orthwestem University
School oï Commerce Library
Chicago
the science
of
y finger prints
Lesson One
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson One
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S A.
Copyright 192 2
by the
Dunlap School of Finger Prints
LESSOX ONE
3
TO OUR STUDENTS
Study some every day. An hour spent each day on
the lessons is better than all of the time put in at once
at the end of the week.
Each student is assigned a class number when he
enrolls. This number must be placed on every lesson,
letter and piece of mail sent to the school. This will
enable us to quickly identify your mail and give you
immediate service. You do not want to be delayed in
your work, so bear this important detail in mind.
Give your full name and address in addition to your
class number.
You are furnished with two lessons when you en¬
roll. When you pass the examination 011 Lesson 1
the third lesson will be sent you. In this way you
will always have one 011 hand to study.
Read the lesson over, first to g"et an idea of the
contents, then go over it again, studying each point
carefully. When you feel certain you have mastered
the text, turn to the examination questions and
answer each to the best of your ability in your own
words. If there are some questions whicli puzzle you,
go back to that part of the text and study it again.
Then answer those questions. If after studying dili¬
gently you still do not feel able to answer some ques¬
tion, write us for special help. Be explicit in your
questions. If your question is in reference to some
part of the text, refer to the lesson number, page
number and paragraph. We will always be glad to
help you.
Number each answer in the margin of the exam-
4 THE SCIENCE OF FINGER PRINTS
ination paper furnished, to correspond with the ques¬
tions in the book. Write out the answers only. Do
not copy the questions.
Use the large return envelope which we furnish
free, to send in your examination for correction. Fold
the papers lengthwise in four even parts. Mail ai! of
your answers to one examination in the same envelope.
Do not send your examination in parts. The small
return envelopes are to be used in making remittances,
and for correspondence in general.
Your corrected examinations will be returned to
you. The passing grade is eighty. Should you fail
to pass we will give you further instruction and help,
and the examination will again be taken by you. No
student will be passed on to his next lesson until he
has reached a grade of eighty.
Just as soon as you pass the third examination the
finger print equipment will be sent to you. You do
not need it before that time.
Should you receive from the school any mail which
has not sufficient postage on it, pay the amount due,
return the envelope in which the mail reached you,
and you will be reimbursed. On the other hand be
careful to place sufficient postage on any mail sent to
the school. Every four sheets of the examination
paper will require two cents postage for first class
mail. Foreign mail will require five cents for the first
four sheets and three cents for each additional four
sheets or fraction thereof enclosed in the same en¬
velope. You are not absolutely required to use our
examination blanks, but the cost is no more than or¬
dinary paper, and their use is a great convenience.
Additional amounts of paper may be bought from the
LESSON ONE 5
school at one cent a sheet. Finger print cards used
for the examinations on Lessons Four and Five and
for practice purposes may be purchased in additional
amounts from the school at 25c a half dozen or 40c a
dozen. Orders for supplies must amount to at least
25c. The overhead is too high to fill smaller orders as
these supplies are sold at cost plus the postage re¬
quired to send them.
Use typewriter, pen or pencil, in writing your ex¬
aminations. Write as plainly as possible and use only
one side of the paper.
Make all remittances payable to Dunlap School of
Finger Prints, 1029 South Wabash avenue, Chicago,
111., by postal or express money order, bank draft, cer¬
tified personal check, or cashier's check.
Re-read this information, and for your own con¬
venience try to comply with our reasonable requests.
It will help us both exceedingly.
FOREWORD:
Lesson One is designed to acquaint the student
with a history of the various methods and means of
personal identification used since it became necessary
to record descriptions of criminals. In the beginning
.memory of faces, general appearance and character¬
istics of individuals were largely depended upon.
Then came photographs, later the Bertillon system
of measurements and finally finger prints.
AVhen Bertillon announced the result of his experi¬
ments it was thought the last word had been uttered
upon this important subject, but a few years of trial
disclosed that there were many weaknesses in Ber-
tillon's plan, magnificent though it was. For instance,
it was definitely determined that measurements taken
& THE SCIENCE OF FINGER PRINTS
prior to the eighteenth year of a man or woman could
not be relied upon, so many changes taking place
after that age.
The pages in this book recount all that the student
needs to know and it will be well for him to pay close
attention to what is imparted to him. After gradua¬
tion and actual employment in the science of finger
prints, he will often be called upon to give expert tes¬
timony in court, and to qualify him the attorneys will
delve into his knowledge of Bertillon as well as Sir
William Herschel, Sir Edward R. Ilenry and Sir
Francis Galton, who devoted their lives to the perfec¬
tion of the science of finger prints.
These words of advice are placed in the front part
of this book for the benefit of students of the Dunlap
School of Finger Prints. If they are followed there is
absolutely no chance of failure. Success is sure to
follow graduation and any man or woman may aspire
to the highest position in this new, honorable and
highly profitable profession.
LESSON I
History of Identification and a Comparison of
Methods.
The necessity of a means of positively identifying
individuals has long been realized by the entire civ¬
ilized world.
The uses to which such a means of identification
could be put are manifold and of inestimable value.
For centuries the various governments of the
world have had to contend with impersonations and
falsification of public and legal documents.
Unscrupulous men in all ages have with more or
LESSON ONE 7
less success forged signatures, assumed names and
used other means to illegally secure money, authority
or make other gains.
The English government first realized the neces¬
sity of a means of identifying their subjects in India
as early as 1855. Previous to that time we have no
authentic records, but it is reasonable to assume that
the Chinese, Egyptians, Greeks and Romans had need
of and used some method of personal identification
during their times of supremacy in the earlier ages-.
Identity must of course be established upon some
personal physical quality, peculiar only to the indi¬
vidual under consideration, and one that remains per¬
manent and unchangeable through the entire lifetime.
Earlier systems have been based upon scars, moles,
tattoo marks, deformities, etc., but none were infal¬
lible, and infallibility is a necessity, or the system as
a whole is not good. Either the marks could be ef¬
faced, duplicated, altered, or else no efficient and
exact means of classifying them could be worked out.
The most successful and practical system that pre¬
ceded finger prints and that is at all used today, is
Bertillonage or Anthropometry. This system, com¬
monly known as the Bertillon system, was devised and
perfected by Alphonse Bertillon in 1882.
As a result of his research work in connection with
identification, he was made chief of the identification
bureau then established in connection with the Pre¬
fecture of Police in Paris.
Bertillon had become convinced there were certain
bony structures of the human body which remained
the same in shape and size from maturity until old
age. Also that the dimensions of the human skeleton
8 THE SCIENCE OF FINGER PRINTS
have wide differences in different subjects. Lastly,
that certain dimensions of the skeleton may be meas¬
ured with little trouble and comparative precision, by
means of calipers of very simple construction.
The Bertillon system is based upon the following
eleven measurements :
Í Height (height when
standing)
Reach (length of out¬
stretched arms from
fingertip to fingertip)
Trunk (height of man
sitting)
¡Length of the head
Width of the head
Length of the right ear
Width of face across
cheekbones
S Length of the left foot
Length of the left middle
finger
Length of the left little
finger
Length of the left fore¬
arm
Figure 1 shows how these various measurements
are taken.
These eleven measurements are shown in a pre¬
scribed order on the Bert-illon signalment, in the milli¬
meter scale. It is upon them that the classification is
based. In a collection of about 100,000 Bertillon sig-
nalments the first distribution is made, according to
the length of the head, into three primary divisions :
namely, short, medium and long.
Each group or division is defined by figures. Each
ABSTRACT OF
THE ANTHROPOMETRICAE SIGNALMEN T
I. Height.
4. Length of head.
7. Left foot.
2. Reach.
5. Width of head.
8. Left middle finger,
(ii)
3. Trunk.
6. Right ear.
9. Left forearm.
Figure 1.
10 THE SCIENCE OF FINGER PRINTS
of the three primary groups is again divided into
three sub-groups, according to the width of the head;
this head width also being separated into narrow, me¬
dium and broad, according to set numerical limits.
This sub-dividing goes on, separating each previ¬
ous accumulation into smaller groups, according to
middle finger length, foot length and forearm length,
the last sub-division reducing each group to about one
dozen cards each.
The fallacy of the system lies in the difference in
measurements made by the same and by different op¬
erators, of one person at different times. The meas¬
urements change as time goes on. This variation in
measurements is due to one or more reasons, such as
a difference in the amount of pressure on the measur¬
ing instruments used by operators; change in the size
of the portion measured, due to growth or shrinkage
of the body; errors made in reading and transcribing
measurements, etc.
When it is considered that an error .of two milli¬
meters, or about two twenty-fifths of an inch, is
enough to frustrate successful search of a Bertillon
record and that the height of the same individual is
often ten millimeters greater in the morning than at
night, the possibilities of error in this system can
easily be seen.
Again, if a measurement falls on one side of the
limit separating a group into small, medium and large,
a search of both compartments must be made to make
sure the search has overlooked nothing.
In his book, Bertillon says the notations of the
body measurements, supported by the knowledge of
the existence of peculiar marks and by the descriptive
LESSON ONE 11
information for the face, are not sufficient to insure
identification if these first measurements were taken
while the subject was under twenty years of age.
Bertillon further says: '"The adding of a photo¬
graphic portrait to the signalment, or measurements,
of a person under twenty years of age, becomes then
so much the more necessary the further toward in¬
fancy it is desired to carry the investigation concern¬
ing identity." In other words, the younger a person
whom you wish to identify, the more necessary it is
to have a picture of that person attached to the card
bearing the measurements.
It should be admitted that as a rule it is difficult to
pursue a verification in the records of the system fur¬
ther back than the twenty-first year, and absolutely
impossible further back than the eighteenth year,
without the aid of a profile photograph from the right
side.
So the student can see for himself that Bertillon,
the author and founder of the Bertillon system, ad¬
mits that his system is practically useless when ap¬
plied to minors. This point is of extremely great im¬
portance, as a very large percentage of criminals break
the laws and are brought to justice before they have
reached the age of maturity. Again, this system
would be of no value as a means of universal registra¬
tion of children, were such registration in effect, as we
have every reason to believe it will be and that in the
not far distant future.
This proposition brings us to the subject of photo¬
graphs as a means of personal identification. A pho¬
tograph, if properly made, will in a few instances be
sufficient for identification between short periods.
12 THE SCIENCE OF FINGER PRINTS
When a period of years passes between the time of
the first and second photographs of a person, a change
in the physical features is bound to occur to such an
extent as to render positive identification practically
impossible.
A good example of this is shown in figure 2. The
two photographs are of Frank Murray. The one to
Figure 2.
h
the left was taken in Toronto, Can., in November,
1908, and the other in Old Town, Maine, in December,
1909, a year later. A person would hardly think they
were photographs of the same man, but the prints of
the left middle finger, taken at the same two times,
prove unmistakable identification.
LESSON ONE 13
A complete disguise is also easily effected, often
rendering photographs useless. For instance, if a
man grows a beard, has his hair cut in a different style
and dyed another color, and wears glasses, just before
a second picture is taken, the two will naturally be
Figure 3.
much different. They would actually look like pic¬
tures of two different men.
Another point that argues against photographs as
a means of positive identification is the fact that sev¬
eral men will resemble each other, so closely in some
cases that it is almost impossible to tell them apart.
Figure 3 shows the photographs of three unrelated
men. The resemblance in this case is close enough
14 THE SCIENCE OF FINGER PRINTS
to raise a doubt, and probably an error, in identifica¬
tion. Their finger prints are totally different.
Another case which is frequently referred to and
quoted in court trials and police annals, which argues
against both the Bertillon system of measurements
and the photographic system, is that of William West,
a negro prisoner in the federal penitentiary at Leaven¬
worth, Kan.
Figure 4.
In 1903, one Will West, a new prisoner, was sen¬
tenced to serve a term of imprisonment at this insti¬
tution. His photograph is shown in Figure 4.
A few days after his arrival he was taken to the.
record clerk with a number of other prisoners to be
measured and photographed. The clerk, remember¬
ing the face of the prisoner, asked if he had not been
committed once before. West emphatically denied
that he had.
The clerk was positive, however, and took the
Bertillon measurements of the Will West then before
LESSON ONE 15
him. At the file he found a card with similar measure¬
ments, and a photograph, the card bearing the name
William West. When the picture was shown to the
prisoner he could not deny that it resembled him (see
Figure 5) but he did deny emphatically that it actually
was a picture of him, declaring he had never been in
the prison before.
The clerk examined the card further and found out
Figure 5.
that William West was still a prisoner in the peniten¬
tiary, having been committed for life in September,
.1901, for murder.
There you have the case. Although their names
were the same, they looked alike and their Bertillon
measurements were practically the same, yet they
were different men. This is probably the most re¬
markable case on record of a resemblance, both in
features and measurements, of two criminals.
Now note this fact and bear it in mind. THE
FINGER PRINTS OF THE TWO MEN WERE EN-
16 THE SCIENCE OF FINGER PRINTS
TIRELY DIFFERENT. This instance, without any
others, thoroughly demonstrates the superiority as a
means of identification, of the finger print system.
The photograph is admitted by experts to be an unre¬
liable means of identification.
"The value of handwriting for identification pur¬
poses will need some discussion. Most of the value
this system can claim is immediately discounted to a
very great extent by the fact that the expert bases his
decision on his opinion. ABSOLUTE PROOF is the
missing quantity in this method, as it. is in the others.
A case is on record where a father and son, both
handwriting experts of the highest repute, gave con¬
trary decisions on the same written instrument, thus
showing that opinions will differ in this as in other
matters.
The handwriting expert bases his opinion on com¬
parison alone. Pie notes the slant of the writing in
question, the way the "t" is crossed, the "i" dotted,
how words are ended, the evenness of the writing, the
average number of words written with one dip of the
pen, peculiarities in forming capital letters, and other
similar items, which might be termed idiosyncrasies
of the writer. Most handwriting experts claim the
ability to read character by handwriting. This phase
is of course beneficial in tracing missing persons and
law-breakers, as a knowledge of habits will often give
a clue to the probable whereabouts of the person
sought, as well as a clue to what actions might reason¬
ably be expected of him.
Aside from the systems considered, namely the
Bertillon, photographic and graphology or handwrit-
LESSON ONE IV
ing, there is none which anywhere near approaches
the finger print in value as to effectiveness and cer¬
tainty. The superiority of the finger print system
over the others has been demonstrated.
Before proceeding further on the subject it is well
to define "finger prints" in order that the student may
thoroughly understand just what a finger print is.
The best definition we have is: "A finger print is a
reproduction on some surface, of the pattern or de¬
sign formed by the ridges on the inside of the first
joint, or tip, of a finger or a thumb."
Now let us go to some extent into the very inter¬
esting history of the origin and discovery of the finger
print system.
Sir Wm. J. Herschel.
Sir William J. Herschel, an assistant under the old
East India Company of Bengal, India, in 1858, and
later magistrate at Hooghly, near Calcutta, is the un¬
disputed discoverer of the value of finger prints as a
means of identification. The discovery was made in
the year mentioned. —
Extensive researches made by Sir Francis Galton,
and an assistant of his at the Legation in Peking,
China, have failed to disclose any previous use of the
ridge formation of finger prints for comparison, to
disclose identity.
The nearest approach to the use of finger prints
previous to discoveries by Sir William Herschel (men¬
tioned in the second foregoing paragraph) was dis¬
closed by the Chinese. It is asserted by a Mr. Bullock,
assistant to Sir Francis Galton, that the Chinese had
a method of signing deeds by use of the fingertips, al-
18 THE SCIENCE OF FINGER PRINTS
though it was not a finger print method or system.
Mr. Bullock was careful to point out that to his
knowledge these marks in most cases were merely for
the moral effect upon the signer.
The fact that the Chinese used water ink, which
will not reproduce an impression of the ridge on the
finger end, proves beyond a doubt that they either
knew nothing of the patterns formed by the ridges or
else they did not care about them. It is natural to
come to this conclusion because the Chinese had dis¬
covered the oil, or printer's ink, long before this time,
this latter ink possessing the quality of clearly re¬
producing lines.
Thomas Bewick.
Thomas Bewick, a wood-engraver, as well as an
author, had a fancy for engraving his finger prints on
the title pages of his books. This was done as far
back as 1809. Mr. Quaritch, a man exceptionally fa¬
miliar with Bewick's life, was asked to investigate
thoroughly as to whether Bervick had written any-,
thing concerning these prints, but no record of such
writings was found. Therefore we must assume that
Bewick did not realize the value of finger prints for
identification purposes.
Johannes Purkenje.
In 1823 Johannes Purkenje, of Breslau, read an es¬
say on finger print impressions. This treatise was
found and examined by Sir Francis Galton. Pur¬
kenje in his work mentions the fact that the papillary
ridges, or ridges on the finger ends, form a variety of
individual patterns, but even in his pioneer work on
the classification of these markings of the fingers he
LESSON ONE 19
does not intimate that he perceived any use or value
they might have as a means of personal identification.
An extract by Galton from the translation of Pur-
kenje's work, delivered in the form of a university
essay at Breslau in 1823, indicates clearly just what
progress he made. It reads in part:
'"Our attention is next engaged by the wonderful
arrangement and curving of the minute furrows con¬
nected with the organs of touch on the inner surface
of the hand and foot, especially of the last phalanx of
each finger. Some general account of them is always
to be found in every manual of physiology and anat¬
omy, but in an organ of such importance as the human
hand, used as it is for ever varied movements, and es¬
pecially serviceable to the sense of touch, no research,
however minute, can fail in yielding some gratifying
addition to our knowledge of that organ. After num¬
berless observations I have thus far met with nine
principal varieties of curvature according to which
tactile furrows, or furrows susceptible to touch, are
disposed upon the inner surface of the last phalanx of
the fingers."
The nine types of fingerprint patterns recognized
by Purkenje were named by him as follows:
Transverse flexures.
Central longitudinal stria.
Oblique stria.
Oblique sinus.
Almond.
Spiral.
Ellipse.
Circle.
Double whorl.
20 THE SCIENCE OF FINGER PRINTS
We will now come back to Sir Wm. Herschel.
The first practical use to which Herschel put his
knowledge of finger prints was in July, 1858. He so¬
licited bids or figures on some binding material he in¬
tended to use in constructing a road in Jungepoor. A
native named Rajyadhar Konai came to terms with
him and drew , up an agreement in his own hand.
When he was about to sign it in the usual way Her¬
schel stopped him in order to read the document. It
then occured to Sir William to have the native stamp
an impression of his hand on the document by way
of signature. This proved so successful that the
practice was continued upon subsequent agreements.
Figure 6 shows the impression of Konai's hand taken
in 1858 at Bengal.
Subsequent experiments by Sir William with his
own hands showed the advantage of using only the
impression of the ridges from the first joint of the
finger, instead of the entire hand. He proved his
theory that the ridges forming the pattern of a finger
print do not change, even to the extent of the course
of a single ridge. That is to say, the same pattern
persists on the same finger at all times. This is one
of the great advantages that finger printing has over
the Bertillon and photographic systems. His proof of
this fact is presented by impressions taken from his
own fingers through a period of fifty-seven years.
Figure 7 is a reproduction of Herschel's prints, show¬
ing the dates on which each set was taken. The stu¬
dent can readily see that all these sets are absolutely
identical in the formation of every ridge. Basing our
judgment on this test it is safe to assert that the ridges
remain exactly the same in form on an individual from
LESSON ONE
Figure 6.
34317
22 THE SCIENCE OF FINGER PRINTS
the sixth month of fetal life until decomposition has
set in after death.
This point brings out an advantage that finger
prints have over photographs. For instance, if the
death of a person has been caused by an accident which
has mutilated the face to any extent, a photograph
would in most cases be well nigh useless. On the
other hand if only a part of the first joint of one finger,
containing the ridges, is found on the corpse, positive
identification can be established.
Sir William made several attempts to bring the
value of finger prints before his government and have
the system officially adopted. In this he did not meet
with great success. His work was not in vain, how¬
ever, for he laid the foundation upon which Sir Fran¬
cis Galton continued to build.
Sir Francis Galton.
Sir Francis continued to extend and perfect the
finger print system where Sir William left off. In
fact for a time he worked contemporaneously with
him. The attention of Sir Francis was first drawn
to the ridges forming" the finger pattern in 1888, while
preparing a lecture on Personal Identification for the
Royal Institution, which subject this society had for
its principal lecture feature. This was an account of
the anthropometric method of Bertillon, which had
been newly introduced into the prison administration
of France. It gave an incentive for further investiga¬
tion, which resulted in the formulation of a system of
classifying and indexing sets of finger print patterns
by Sir Francis.
Three types are set forth by Galton, under one of
LESSON ONE 23
which all fingerprint patterns must be included.
These three types are known as the Arch, the Loop
and the Whorl. Galton's definitions for these pat¬
terns have been accepted and are practically the same
as used today.
W. J. H., 1859, Arrah (aet. 26).
> r. 1 r. 2 r. 1 r. 2 (rf)
W. J. H., March 31, 187? W. J. 11., February 22, 1916 J
Figure 7.
Sir Francis suggested that finger print impressions
should always be placed in natural sequence. In clas¬
sifying a set of finger prints each pattern was des¬
ignated by the symbol "A," "L" or "\V," representing
Arch, Loop or Whorl.
24 THE SCIENCE OF FINGER PRINTS
In indexing or filing, three, six or ten prints could
be used to constitute a set. These sets were then
filed alphabetically in chronological order. Thus in a
three finger print set, a card bearing the classification-
"a a a" would precede one with a formula "a a 1," like¬
wise "11 w" would precede "w w w." Sir Francis also
separated his loop type into sub-groups by counting
the number of ridges appearing between two fixed
points which he defined in that type.
At the request of Sir William, extensive researches
were conducted by Sir Francis into the earlier uses of
finger prints. Frcm the material gathered he formed
the opinion that in previous times only the tips of the
fingers were impressed and that their use was merely
of a superstitional and ceremonial nature. Later th e
size and shape of the impression was considered, much
as a shoe or foot print of today. Galton claims that
so far as he can learn, no higher form of finger print¬
ing than this has existed, in regular and well-under-
stcod use, in any barbarous or semi-civilized country.
Ridges could not have been seen at all in such rude
prints. His work, therefore, dealt mostly with the
classification, formulation and indexing of finger print
patterns. He also made computation as to the prob¬
abilities of two finger print impressions taken from
different persons being identical. For a basis of com¬
parison he used peculiarities of ridge formation which
he called "characteristics."
These were five in number: 1, bifurcations, where
a ridge forked or split in half, forming two branches;
2, abrupt endings, where a ridge terminated sharply
inside of the pattern; 3, short line ridges, or those hav¬
ing a beginning and ending inside the ridge pattern;
LF.SSOX OXE 25
4, ridge dots; 5, islands, where a ridge would fork or
bifurcate, the two branches again uniting further
along in their course.
From these calculations he makes the statement
that theoretically there is only one chance in 64,000,-
000 of two prints taken from different persons being
alike. That is on one finger. When all ten fingers
are taken into consideration, the possibilities become
one to 640,000,000. This theory has been proved to
be true, as two identical prints have not yet been dis¬
covered.
Sir Francis' system of classification and filing was
not accepted by the government with much more suc¬
cess than was Sir William's. It was examined by a
special commission appointed by the Home Secretary
This commission, while recognizing the many excel¬
lencies of the system were of the opinion that it did
not have so effective a means of primary classification
as the Bertillon system. As a consequence they rec¬
ommended a dual system under which the primary
classification should be made according to Bertillon's
method of measurements and the secondary classifica¬
tion according to finger print impressions. This rec¬
ommendation was approved by the government and
the dual system used until 1901.
Sir Edward R. Henry.
At that time experiments were being made in Ben¬
gal with the finger print system by Sir E. R. Henry,
commissioner of police of the city of London, who
took up the work where Sir Francis left off. To
1 lenrv must be given the credit for devising a practical
method of filing and classification. He worked out
26 THE SCIENCE OF FINGER PRINTS
nine standard types, corresponding somewhat with
those of Purkenje, under which all patterns must fall.
Sets of ten finger prints were first filed with a key, by
a process of elimination. Later on he adopted the nu¬
merical system of filing by dividing his nine types into
two groups, and assigning certain numerical values to
each. These, when added, would result in a fraction.
The numbers composing this fraction represented the
drawer or cabinet in which that set would be filed.
Henry's primary classification was a great im¬
provement over Galton's. His work, however, con¬
sisted principally of devising a system of classification,
formulation and filing of ten-finger sets of prints.
The system devised by him with slight modifications
and extensions has been accepted as the standard and
is universally used today.
An application was made to the government of In¬
dia for the appointment of an independent commission
to inquire into and report upon Henry's system. This
commission was composed of Gen. Strahan, R.E.,
Surveyor General of India, and Mr.- A, Pedler, F.R.S.
The commission, after a careful investigation and
weighing of the merits of each system, came to the
conclusion that for five reasons the finger print sys¬
tem of recording and classifying, devised by Sir Ed¬
ward and used in Bengal, was superior to the Bertillon
system or Anthropometry. These five reasons were :
1, simplicity of working; 2, the cost of apparatus;
3, the fact that all skilled work is transferred to a cen¬
tral classification office; 4, the rapidity with which the
process can be worked; and 5, the certainty of results.
Upon the receipt of this report the Governor Gen¬
eral directed by a resolution that after June 12, 1897,
LliSSOX O Ml 27
the finger print system of identification for criminals
was to be adopted and used generally in British India.
Mary E. Holland.
Mrs. Mary E. Holland of Chicago visited Scotland
Yard and made an extensive study of the finger print
system in use there in 1904. She was one of the ex¬
perts who introduced and established the system in
the United States.
Upon her return to the United States she installed,
for the federal government in Washington, D. C., one
of the first bureaus of finger print identification in
America. Later Mrs. Holland made an extensive tour
of the police departments and penal institutions of the
country, making further installations of bureaus, and
instructing the various identification experts as to the
methods of using and maintaining the finger print sys¬
tem. From that time on its use has spread rapidly,
until it is now used by banks, express companies, fac¬
tories, the Post Office Department, Civil Service Com¬
missions, universities and many other institutions.
All of the foregoing history is of the utmost im¬
portance. When you are called into court to testify
as an expert witness, you must be able, if necessary,
to relate the origin and history of fing-er printing and
to point out its superiority over other systems.
Therefore it is necessary that you assimilate all of the
historical facts given in this lesson. Do not cease
your work or be satisfied until you have mastered it.
EXAMINATION QUESTIONS ON LESSON I
(1) What is the value of being able positively to
identify human beings?
28 THE SCIENCE OF FINGER PRINTS
(2) What were the three systems used prev¬
iously to the adoption of finger prints?
(3) Summarize each system and point out its de ¬
fects.
(4) Name in order the founders and perfectors
of the finger print system and tell what each accom¬
plished.
(5) What is a finger print?
(6) When was the finger print system officially
adopted by the British government?
(7) What are the five advantages of the finger
print system as reported by the independent commis¬
sion composed of Gen. Strahan and Mr. Pedler?
(8) Does the finger print pattern ever change on
a person's fing-er ?
(9) What are the chances of two finger prints
being alike?
(10) For how long a period do the ridges of the
fingers persist on the human body?
Note—Your answer to each question will count
for ten per cent of your grade on this lesson.
ABOUT LESSON TWO
In the next lesson the student takes up the actual
study of finger prints. He is taught the significance
of the ridges which appear upon all five fingers of each
hand, why nature placed them there in the very be¬
ginning of life and how it transpires that the impres¬
sions left by the finger prints of a baby are just the
same as those left by the man or the woman.
Finger prints never change from the cradle to the
I.ESSOX OXE 20
grave, and what is more remarkable, there are no two
sets of finger print patterns alike—not one chance in
640,000,000 of the finger prints of any two persons
being the same. This means, of course, that in all the
history of finger prints the finger tip impressions of
two people have never been found to be exactly alike.
They may be similar in many respects, but there is
always a distinguishable difference.
This is why the science of finger prints is such an
interesting study. And it is a simple science. There
is nothing in the entire Dunlap course to baffle or
confuse the student. Learning the letters of the
alphabet and becoming acquainted with numerals are
accomplishments far more difficult. In fact, it may
be said that when you learned your A, B, C's you
learned your first and hardest finger print lesson.
You learned to remember certain outlined formations
which is all there is to finger prints. In a very short
time you will come to know one from the other and
immediately after you will start in classifying the
different types.
It behooves the student, therefore, to go slowly
over the fundamentals. They are easy to understand
and 011 that account some pass them over lightly, but
they are the basis of the entire system. Learn
surely as you go. After the first few lessons you will
get along with marvelous speed. And at the end of
the course you will be ready to enter the professional
field where you will be called upon to take and record
the finger prints of celebrated criminals. If you do
not care for a career in connection with the police de¬
partments of the country or the federal government,
you will find that thousands of large commercial or-
30 THE SCIENCE OF FINGER PRINTS
ganizations maintain finger print bureaus, that insur¬
ance companies have them and that banks have dis¬
covered they cannot get along without them. There'
are literally thousands of opportunities for the finger
print expert, which you will be when you have finished
the Dunlap Course.
i
THE SCIENCE
of
FINGER PRINTS
Lesson Two
Dunlap School of Finger Prints
1029 South Wabaah Avenu«
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Two
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Ill'nois
U. S. A.
Copyright 1922
by the
Dunlap School of Finger Prints
TO ALL AMBITIOUS STUDENTS:
You are now about to receive your primary in¬
struction in the science of finger prints. Please pay
close attention to all that is published in this book. Be
certain that you understand before you send in your
examination papers. If you are in doubt about any¬
thing, pause and write a letter to the school explaining
the point that is puzzling you.
An effort has been made to make this lesson so
clear that not a sentence will bother you. It has been
said by those who know, that this is the very best and
most perfect finger print course ever compiled, and
the truth is that hundreds—yes, thousands—of stu¬
dents have written in praising the simplicity of the
lessons. And when it is said that graduates of other
schools have taken the Dunlap Course before they
could qualify as finger print experts, you will be sure
that this is a superior correspondence course—the one
course that assures success.
It is the desire of the management that Dunlap
students become expert in the shortest possible space
of time so they can join the ranks of a profession that
is constantly calling for more and more competent
operators, but it does not mean by this that students
should hurry over their lessons in order to break speed
records. It will be better, as has been previously
stated, to go slowly and be sure that you are master¬
ing all phases of each lesson. Xo sounder advice can
be given. The student will now proceed with Lesson
Two.
LESSON II
Physiology of the Friction Ridges.
This lesson comprises an anatomical study of the
embryology, or very beginning", as well as the phys¬
iology, of the papillary ridges found on the under sur¬
face of the hands and feet of the human body.
Papillary, or friction ridges, are the minute raised
furrows of skin found on the palm of the hand, tips of
the fingers and soles of the feet. It is with the ridges
found on the final phalanx of the digits, or ends of the
fingers, that we are now concerned.
These friction ridges can be found on the paws of
many animals, and especially on those of the ape fam¬
ily. In animals the ridges perform the function of
preventing slipping, to which such animals as the ape,
squirrel and other tree climbing animals are likely to
be subject, during their rapid movements through
the branches. The alternate ridges and depressions
create suction when pressed against a hard surface.
It is evident therefore that the presence of these
ridges on man is due to some hereditary tendency.
If the student will closely and carefully examine
the surface of the skin on the inside of the first joints
of his fingers (if possible using a small magnifying
glass) he will see that these ridges on the finger tips
stand out prominently and are of an intricate forma¬
tion. They form différent shapes, patterns and de¬
signs. The student should also examine the fingers
of several other persons, and note the general ar¬
rangement of these ridges, the varying direction of
LESSON TWO 5
their course over different areas, and especially the
patterns in their endless varieties.
The embryology of the ridges will find its expla¬
nation in comparative anatomy. The primitive
ground mammals developed eleven pads on the contact
surface of each foot. The main purpose of these was
to cushion the weight of the body. Around these
pads were folds of skin of a triangular or diamond
shape. These pads ran transversely across the sur¬
face, forming parallel rows. In this direction they are
best suited to prevent slipping. In more modern
forms of life, such as the arboreal monkeys, the ridges
upon these pads form themselves into circles and com¬
binations of loops and spirals. This is the first ap¬
pearance of true patterns corresponding to those on
the human hand.
Physiologists are not agreed as to the function of
the friction ridges on the human body. The theories
which are most generally accepted are explained in
subsequent paragraphs.
Students of anatomy have found that the seat of
the touch sense is located under the epidermical sur¬
face of the skin. For instance, when the fingers are
brought into contact with any surface, there is an ef¬
fect on the ends of the nerve fibres producing a sen¬
sation which is transmitted to the brain.
A minute scrutiny of the ridges on the finger ends
with a magnifying glass shows very small pores or
holes, equidistant apart on each ridge. With greater
magnification, these pores or ducts will be shown to
be located on top of a small mound, these mounds be¬
ing so close together that the naked eye gets the im¬
pression of a continuous line or ridge. The ducts or
6 THE SCIENCE OF FINGER PRINTS
glands are tubular in shape, extending deeper into the
skin. The inner extremity of each is coiled upon it¬
self several times, forming a little ball, or sac. This
sac is situated in the derma, or subcutaneous connec¬
tive tissue.
From this coil the duct passes straight out to the
epidermis or surface skin. Through the surface skin
it makes a few spiral turns, after which it opens ob¬
liquely on the top surface of a ridge. The gland con¬
sists of a base membrane which is supplied abundantly
with blood vessels. From the blood is secreted a
watery fluid which is commonly called sweat or per¬
spiration. This sweat is carried to the surface by the
ducts and spreads over the ridge. This is one method
the body has of excreting or getting rid of waste.
Physiologists are also of the opinion- that this sweat
is constantly supplied to the skin surface to oil it up
and keep it soft and pliable. AVhen the finger touches
a smooth object this sweat adheres, leaving an impres¬
sion of the patterns formed by the ridges, in other
words, a FINGER PRINT. It is because of such im¬
pressions accidentally left by many lawbreakers that
they are finally brought to justice.
. This subject of latent finger prints is extremely im
teresting, as well as useful. One whole lesson is given
to the subject.later in the course. ;
: ' Figure 1 shows a cross section view of a portion
of the skin of a male person. In this illustration, "A"
is the epidermis or outer skin layer,. "1>" is termed
the clear layer. "C" is the mucuous layer. P'D" is the
spiral outlet of the duct to the top, of the ridge. "E"
is the duct, carrying the sweat to the surface. "F" is
the sweat gland. .
LESSON TWO 7
Some scientists are of the opinion that the skin is
corrugated, that is to say, arranged into alternate
ridges and depressions, to render it tougher and
stronger than the plain smooth skin. This is with the
view in mind that the hands and feet are subject to
more wear and tear from manual labor than any other
Figure 1.
part of the body. It is known that manual labor of the
ordinary kind will strengthen and develop the ridges,
making them larger and heavier, and that the fingers
of a lady, or of an office employe will have a very deli¬
cate and finely drawn ridge formation.
The theory of the prevention, by the ridges and
depressions, of slipping, is maintained as applied to
humans as well as animals.
8 THE SCIENCE OF FINGER PRINTS
All of these theories can be accepted. One is as
good as the other, and a combination of all is in all
probability the final solution.
The subject of ridge destruction, its cause and re-:
suit, is of especial interest jand importance to the fin¬
ger print expert. The student should make himself
very familiar with it.
There are two kinds of ridge destruction; one, in
which the surface skin only is affected, causing merely
a temporary destruction ; the other is a permanent
ridge destruction. The latter will result when an in¬
jury or a disease is of such a nature that the ducts or
glands are killed. The important thing is, however,
A Figure 2. B
that when the ridges do return, they form exactly the
same pattern as before.
Any number of reasons can be assigned for causes
of temporary ridge destruction. Many skin diseases
will cause only a temporary destruction. Figure 2
illustrates this. The print "A" shows a wart. A wart
always has the appearance of a white circle sur¬
rounded by a black ring. The reason for the black
ring is that the ridges have been pushed aside by the
growth of the wart crowding together around it. The
center of the wart is hollow, or lower than the ridges
LESSON TWO »
surrounding it, so that when the finger is inked, by-
pressing on a glass slab, the center of the wart does not
come in contact with the ink. Therefore, when the
print is impressed on the paper, the center of the wart
will not leave, any mark^.- When a wart disappears
the ridges affected by it resume their original course
and shape. Print "B" in Figure 2 shows the same print
after the disappearance of the wart. Examine the af¬
fected ridges very closely and note how perfectly they
have returned. In comparing two prints for identity
place no reliance on this kind of a growth. The rea-
Figure 3.
son for this is obvious, as one print might show a wart
very prominently while no trace of it will be shown in
another copy of the same print made at another time.
Creases or folds of the skin are also of a temporary
nature. Figure 3 shows a print in which several
creases are visible. Creases appear as thin white lines,
diagonally crossing the ridges. They very frequently
are found on the fingers of very young and very old
persons. Usually, creases are not prominent enough
to obstruct the pattern or hinder proper classification
and will often disappear entirely.
ft) THE SCIENCE ¡OF FINGËR PRINTS
Another common form of ridge destruction is
caused by manual labor of various kinds where the
hands are used to handle objects with rough or sharp
surfaces such as pig iron, rope, panes of glass, boxes
and crates; also by wielding heavy tools such as
shovels, axes, hammers. In other cases the ridges will
become burned or eaten away by having the hands
submerged in commercial acids of various kinds. The
alkalis in the soaps and cleaning powders used by the
housewife has the same effect on the fingers as the
acids, and will often cause a destruction of the ridges.
These varieties of ridge destruction are all of a tem¬
porary nature and if the hands are kept away from
the destructive agent for any length of time the ridges
will return, resuming the same form and pattern as
before the destruction took place.
When you are called upon to handle a case where
the ridges have been destroyed, make a careful exam¬
ination of the hands and ascertain whether the de¬
struction is severe enough to be permanent. If not,
arrange to take another set of prints after the ridges
have grown back again, in order to g'et the best avail¬
able results. Ridges which have been temporarily
destroyed will grow back to normal within a very
.few weeks.
Never be satisfied with an indistinct set of prints
if it is at all possible to get anything better.
Be very cautious while handling a subject upon
whose fingers there are blotches, pimples, or any in¬
dication of the skin peeling or scaling, as the affliction
might be contagious and of a serious nature. The
expert should be certain to wash his hands in an anti-
LESSON TWO 11
septic solution immediately after handling such a sub¬
ject. Clean your instruments thoroughly before tak¬
ing the next set of prints.
In some cases where the hands are diseased the
ridge destruction will be permanent. In some cases
it is hard to decide whether it will or will not be per¬
manent, merely by examination, so it is best to take
the prints of the subject in the condition they are at
the time and get the best results you can. At a later
date a good set of prints can be substituted if the de¬
struction has proved to be temporary. At any rate
you will have one set on file.
In all of the cases outlined above, the ducts have
not been affected. We will now turn our attention
to the causes and result of permanent ridge destruc¬
tion.
As previously mentioned, the ducts are destroyed
in all cases of permanent ridg'e extermination.
Ulcerated sores are fibrous growths which work
deeply into the skin and will kill the ducts. They will
have the same appearance as a wart on a finger print.
Ulcers are of a permanent nature and will leave a scar.
Scars caused by cuts are also permanent. The im¬
pression made by a cicatrix, or scar, very closely re¬
sembles a crease. In a scar, however, the ridges will
pucker, or turn in one direction on each side. The di¬
rection in which the ridges pucker depends upon the
way the cut runs. Thus if the cutting instrument
crossed from left to right the ridges will pucker in
that direction on each side. Scars caused by severe
burns are also of an enduring nature.
Figure 4 shows a permanent scar as discerned in
a finger print impression. Scars when appearing in
12 THE SCIENCE OF FINGER PRINTS
two impressions taken of the same finger at different
times serve as a good characteristic of comparison,
and it is oftentimes useful to note them. Too much
reliance should not be placed in them, however, as a
Figure 5.
very light cut will not always kill the ducts and so
the scar left by it is not necessarily permanent, and
may disappear in the course of time.
EXAMINATION QUESTIONS ON LESSON II
(1) What is a ridge?
(2) Of what use or value are the ridges to man?
(3) What are ducts?
(4) What are their purposes?
(5) To what two degrees may the ridges be de¬
stroyed?
(6) What are some causes of temporary ridge de¬
struction?
(7) What are some causes of permanent ridge
destruction?
(8) What caution should be exercised after tak-
LESSON TWO 13
ing the prints of a person with a diseased condition
evident on his hands?
(9) What is a crease?
(10) How may a crease be distinguished from a
scar on a finger print?
Note—Your answer to each question counts for
ten per cent of your grade on this lesson.
IMPORTANCE OF LESSON THREE
Too much emphasis can not be laid upon the im¬
portance of Lesson Three. It is such a long lesson
that it has been divided into two parts with exam¬
inations for each section, but this does not mean any¬
thing more than that it has been made easier to digest.
Lesson Three, bear in mind, gives you the entire
gist of the science of finger prints. You get all there
is to know, or nearly all, about the different finger
print formations, their names and how they are recog¬
nized when placed upon paper.
It is in your interests, then, that caution is here
given. Lesson Three is so interesting—so completely
absorbing—that you will not want to leave it until
you have it down pat, but it is not well to cram it into
your mind. Take time to go over it slowly first, from
start to finish, and then settle down to careful study.
Memorize the different points brought out and get
so you can tell any finger print pattern as soon as you
see it, especially with no words to guide you. Then it
can be said that you have mastered the greatest of all
finger print lessons.
Lesson Three of the Dunlap School of Finger
14 THE SCIENCE OF FINGER PRINTS
Prints is an improvement upon all similar works. It
is made so simple that a child can comprehend, but
there is so much to it, lucid as it is, that it will require
time in which to assimilate it.
But when you have successfully passed Lesson
Three you are well on your way to finger print suc¬
cess. After that if you are as honest with yourself as
the Dunlap School is with you, it will be but a short
time before you will be numbered among the finger
print experts of the country.
Do not delay in getting Lesson Three. We pre¬
dict you will be wonderfully pleased with it and will
thank your stars that you selected the Dunlap School
of Finger Prints through which to become a profes¬
sional finger print expert.
THE SCIENCE
Í ; ■ " :
of
í - :
FINGER PRINTS
:* ». • "
Lesson Three
Dunlap School of Finger Prints
1029 South Wabash Arenue
Chicago, Illinois
U. S. A.
Copyright 1922
by the
DiinUp School of linger Prints
PATIENCE IS A VIRTUE
In studying the lesson in this book, presented in two parts
with two examinations, patience is a quality you must culti¬
vate if you do not already possess it. But we believe the
average ambitious person has sufficient patience. Do not try
to hurry. Study carefully—understand as you go. First,
however, read the book from beginning to end and then start
in and glean the golden drops of wisdom it imparts. The
reward is so great that none can lightly ignore this advice.
Here's what you accomplish when you successfully pass the
examinations :
Practically you master the entire science of finger prints
so far as the fundamentals are concerned. After that all you
have to do is familiarize yourself with the trimmings—the
embellishments that round out a perfect science—an exact
science.
Yes, finger prints have been reduced to a science and you
will be a scientist when you graduate from the Dunlap School
of Finger Prints. You will discover that the word "science"
has no terrors for ycu. It is just as easy to learn this science
as it is to learn to waltz—easier for many—maybe much
easier for you. But ycu must learn as you go.. If at any time
you cannot get the exact meaning of an illustration or a
statement, sit down and write for an explanation. One will
be immediately sent you.
But we do not believe you will be stumped. We believe
you will wade through this lesson with the same speed you
would show in any contest requiring a little effort.
FOREWORD
This lesson differs somewhat from the others in
that it is divided into two separate parts and contains
two sets of examination questions.
Because of the extensiveness and extreme impor¬
tance of the subject matter covered in lesson three it
was deemed advisable to separate it in this way. This
lesson comprises the fundamentals or basic principles
of the entire classification system. There is so much
important information in it that a student cannot
g'lean all the value it contains by studying it as a single
unit. Dividing it into two natural portions of equal
length makes possible a thorough and lasting knowl¬
edge of the essential details.
We will therefore require that you prepare the
answers to the first set of questions when you have
thoroughly mastered the text up to that point. Send
the papers to the school for correction before taking up
the second part. On your examination paper, indicate
in the "lesson number" space which part of the lesson
it covers. You must correctly answer at least sixteen
of the twenty questions on each of the two parts be¬
fore passing on to lesson four.
LESSON THREE 3
LESSON THREE.
(Part One.)
Types of Patterns.
All finger print patterns are arranged into eight
groups, according to certain general formations of
the ridges common to each group. The names as-
signed to these groups define or describe the form or
pattern to some extent. Thus, under the Arch type,
one finds patterns in which the ridg'es extend from
one side of the print to the other with a slight eleva¬
tion in the center. In the Loop type the general trend
of the ridges is in the form of a loop. It is upon this
arrangement or compilation of patterns that the clas¬
sification, and the indexing of the finger print system
is based.
The eight groups, or types of pattern which are
spoken of in the foregoing paragraph are, 1, the Arch;
2, the Tented Arch; 3, the Loop; 4, the Whorl; 5, the
Central Pocket Loop; 6, the Lateral Pocket Loop; 7,
the Twinned Loop, and 8, the Accidental.
A ninth type was recently instituted and adopted
by all experts in the United States at the annual con¬
vention of the International Association for Identifica¬
tion held in Minneapolis, August, 1920. This is
known as the Exceptional Arch. It will be explained
at a later time.
In order that the primary classification may be de¬
termined, these eight (or nine) types are divided into
two groups. One is known as the Non-Numerical and
the other as the Numerical. Under the first heading
are embodied the arch, tented arch (exceptional arch
included) and loop. Under the numerical heading- fall
the whorl and composite. Composite is a term used
4 THE SCIENCE OF FINGER PRINTS
to embrace central pocket loops, lateral pocket loops,
twinned loops and accidentals. The following table
demonstrates this clearly :
Non-Numerical Group
1—Arch
2—Tented Arch
3—Loop
Numerical Group
4—Whorl
( Central Pocket Loop
. ) Lateral Pocket Loop
Composite yr • , T
1 JI wmned Loop
(Accidental
A clear, concise understanding of the eight types
of fing-er print patterns is an absolute necessity to the
finger print expert. He must be able unhesitatingly
and positively to name the class to which any finger
print belongs. Unless he can do this, his formulation
and filing will be faulty.
Before proceeding further with this lesson learn
the names of the eight types of patterns and their
collection into the Numerical and Non-Numerical
Groups, so you can recite them and tell which group
each belongs to without referring to the text.
TYPE LINES, DELTA AND CORE.
All patterns of the loop, whorl and composite type
have two fixed points or formations, viz., the "core"
and the "delta." The core is the inner terminus or
center of the pattern and the delta is the outer ter¬
minus or extremity of it.
Type Lines.
Deltas are formed in several ways, but always in
Figure 1.
consequence of the "Type Lines." The two diverging
ridges closest to the core or center of the pattern are
the type lines. By diverging" ridges we mean two
ridges which have had a parallel course and then at one
common point separate or spread away from each
other. One of the diverging ridges follows around the
top of the pattern and the other has a course around
the opposite side of the pattern. In the Sketch A of
Figure 1, "A" and "B" are the type lines. "C" is the
point of divergence in the type line of Figure 1.
Sketch A.
Figures 2 and 3 are of several patterns—the
loop, whorl and composite being represented. The
type lines are marked in each print by the letters "TL."
LESSON THREE 7
Figure 3.
S THE SCIENCE OF FINGER PRINTS
Make a careful study of this figure and make sure you
have the idea well fixed in mind before proceeding.
The Delta.
As has been mentioned, the delta forms the outer
terminus of the finger print pattern and is formed in
consequence of the divergence of two ridges called
type lines. The delta may be formed in any one of
several ways, but it always is the very first ridge im¬
mediately following" and in front of the type lines.
The first thing" to do when looking for the delta
therefore is to place these type lines. When you have
satisfied yourself as to which these are in the pattern,
determine which ridge immediately follows their di¬
vergence. In the majority of cases it will be a bifur¬
cation. A bifurcation is a single ridge which splits
in half, or forks, forming two branches. The course
of each branch must be parallel to the type lines, that
is, both branches of a bifurcation must not take the
same or a course parallel to each other after forking.
Sketch B of Figure 1 shows a delta formed by a bifur¬
cation at "E." The ridges "F" and "G" are the type
lines. In sketch C the point "H" is a bifurcation but
both segments of the fork have a parallel course. This
ridge would not form the delta, but would be con¬
sidered one of the type lines with "I" as the other one.
Two ridges coming" together in the form of a
spread out letter V as "<" would not be considered a
bifurcation, so such a formation would not form the
delta unless it immediately followed two diverg-ing
ridges.
In some instances a ridge will bifurcate several
times. In such event the bifurcation or fork closest to
LESSON' THREE 9
the core or center of the pattern is the delta. Sketch
D of Figure 1 shows this. The bifurcation "J" is
the delta.
When a bifurcation is absent the ridge formation
immediately following the type lines constitutes the
delta or outer terminus. It may be only a ridge dot, a
short line ridge, a ridge extending from one of the type
lines, or a ridge turning back on its own course. The
Sketch E Figure 1, illustrates the delta formed in
these various ways. In the sketch, as it is, the ridge
dot "N" forms the delta, being the first ridge forma¬
tion immediately following the type lines "O" '"P."
If this ridge dot "N" did not exist in this pattern, the
ridge "M" springing from the type line "O," would
be the delta. Likewise if both "M" and "N" were
missing in this sketch, the ridge "L" which turns back
on its own course, would be considered the delta. If
all three formations "N," "M" and "L" were missing,
the short line ridge "K" would be the delta, et cetera.
It is necessary to mark the exact point of delta in
most loops, for several reasons which will be dis¬
cussed under classification. In the event of a bifurca¬
tion the "point of delta" is the forking point itself,
or the apex of the angle formed by the fork. In case
of the delta being formed in consequence of diverging
ridges the point of delta will be a point on the ridge
immediately following the divergence, or the delta
ridge, exactly opposite the center of the diverging
ridges. See Figure 4. The circle shows the point of
delta in each sketch, directly opposite the middle of
the divergence of the type lines. The arrows indicate
the direction of the center of the pattern.
HI THF. SCIENCE OF FINGER PRINTS
Figure 4.
The delta must be formed in either one of the two
ways explained. In summarizing, we can form the
following rule for locating the delta: First look for the
type lines, then for a bifurcation immediately follow¬
ing. In case of the non-existence of a bifurcation,
select the ridge formation immediately following the
type lines. In loop patterns, see pages 16 and 17, the
delta may be on either the left or right side of the loop,
depending on the direction in which the ridges of the
loop slope. If the loop inclines to the left the delta
will be on the right side of it. If the loop slopes down¬
ward to the right the delta will have a position to the
left of it. Whorls and Composites, see pages 32 and
37, will have one delta on each side of the pattern, the
type lines opening to the right on the left side and to
the left on the right side.
In Figures 2 and 3 the deltas are all indicated.
Study each of these delta formations very carefully.
The Core.
The core is the inner terminus .or center of the pat¬
tern. The core is of importance only in the loop type
of pattern where it is of especial use in the sub-classi¬
fication as you will learn in a later lesson.
In determining the location of the "point of core"
in the loop type of pattern, the envelope or innermost
LESSON THREE 11
loop is selected. A loop is a ridge which enters the
pattern from a lower corner or side, has an angling
course upward toward the diagonal corner of the pat¬
tern, arcs around, or recurves, again resuming a
course parallel with the entering ridge, and leaving
the pattern from the same source it entered. The
Sketch A of Figure 5 illustrates a loop ridge, or "en¬
velope.''
corev
core
core
If a loop forms the innermost ridge lineament, the
point of core is located on this loop at the point where
the recurve ends and the ridge straightens out farthest
from the delta; that is at the shoulder farthest from
the delta. Sketch B of Figure 5 shows the core
formed in this way.
More often there will be one or several rods or
ridges extending upward inside of the envelope or um¬
bilical loop. These rods, in order that they may form
the core must not touch the envelope. In other words
the tip must protrude inside of the envelope, indepen¬
dent of it. If one such rod protrudes inside the en¬
velope the top or end of it forms the core. Sketch C
12 THE SCIENCE OF FINGER PRINTS
of Figure 5 shows the core formed in this way. If
two rods are displayed, the top of the rod or ridge
farthest from the delta contains the point of core.
Sketch D of Figure 5 depicts the core formed in this
manner. If there are three ridges, the top of the cen¬
ter ridge is the core; (see Sketch E, Figure 5). In
the case of four ridges appearing, the two outside
ridges, that is the ones nearest each side of the en¬
velope, are disregarded. Only the two center or mid¬
dle ridges are considered. Of these two the top of the
one farthest from the delta is the core. See Sketch F,
Figure 5. If more than four ridges should make their
appearance, apply the rule : When the inside of the
envelope consists of an uneven number of rods, the top
of the center ridge is the core. When an even number
of rods appear, select the middle two. Of these two
the top of the one farthest from the delta forms the
core. See "G" and "H" of Figure 5.
A rod may be a ridge sprung from one side of the
Figure SA.
envelope ridge by bifurcation as the left one in "G," or
two rods may be formed from a bifurcation as the
fourth and fifth rods in "H." The essential part is that
the tip projects inside of the center loop without com¬
ing in contact with it.
LESSON THREE 13
Figure 6.
Figure 5A shows several irregularities in the for¬
mation of the core which will be met with, where rods
protrude inside of the envelope and extend into or
14
THE SCIENCE OF FINGER PRINTS
touch the loop ridge. The circle indicates the exact
location of the core in each case.
Figure 6 shows two loop patterns. The cores
are indicated in each one, also the deltas. Study these
as you did Figures 2 and 3 of the deltas.
We define a loop as a finger print pattern in which
at least one ridge must recurve and pass between the
core and delta on the same side it entered. In the
sketch, Figure 7 the ridge "AA" forms such a loop.
You will note that it enters just below the middle of
the left side of the pattern and inclines upward to the
right. At the apex it bends around, in a semi-circular
manner, declining toward the left, parallel to the en¬
tering ridge, leaving the pattern from the same side
it started. Note especially that the entire loop is lo-
Loops.
A
A-
Figure 7.
LESSON THREE 13
cated on the same side of the delta, which is marked
"B." In this particular pattern there are several
i idges which form loops by recurving and making their
exit on one and the same side of the delta. In order
that a pattern be classified as a loop it is only necessary
though that one ridge possess these recurving feat¬
ures.
In order that the ridge can be properly called a re¬
curving one, the loop part, or where it bends or arcs
around, must be perfectly rounded. Sometimes a ridge
will turn back on itself and form a sharp point or barb
at the top. Such a formation could not properly be
called a recurving ridge, nor a pattern containing only
such a formation, a loop. Sketch E of Figure 8 il¬
lustrates a loop formed by a recurving ridge, while F,
which might be mistaken for a recurving ridge is not
one, and illustrates the point brought out above.
E
Figure 8.
Radial and Ulnar Loops.
Loops are sub-divided into Radial and Ulnar, ac¬
cording to whether the ridges forming the loop slope
from left to right or from right to left.
16 THE SCIENCE OF FINGER PRINTS
This sub-division into ulnar and radial is very sim¬
ple but the fact that the slope of the loop will be re¬
versed on one hand from the other makes it a little
confusing at first.
In the forearm extending from the elbow to the
wrist, or the base of the hand, are two large bones.
The bones are anatomically known as the ulna and the
radius. The radius is the smaller of the two and is on
the thumb side of the arm. The ulna is the larger
and is located on the little finger side of the arm. Ulnar
and radial loops derive their names from these bones,
depending upon which one the open end of loop points
to.
Radial Loops.
A loop is radial when the ridg'es forming it slope
downward from the direction of the little finger to¬
ward the thumb, or toward the radius bone. Thus in
an impression of a radial loop from the right hand, the
loops will slope downward from right to left. As the
thumbs are located on opposite sides of the hands, an
impression of a radial loop on the left hand will have an
opposite slope from one on the right hand, or from
left to right. Note that the word "impression" is em¬
phasized in the foregoing sentence. If you examine
a loop pattern directly from the finger.by looking at
your hand, the loop will slope differently, or in an op¬
posite direction from that of an impression, taken
from the same finger. This is natural, because in ex¬
amining the finger, the inside or palm side of the hand
is toward you, while in making an impression you
press that side down, and the back of the hand or the
outside, is toward you. To eliminate any possibility
LESSON THREE 17
Figure 9.
of confusion, therefore, never consider a loop as slop¬
ing from left to right or right to left, but always as to
whether it slopes toward the ulna or radius bone of the
forearm.
Sketch "A" in Figure 9 represents the slope of a
radial loop on the right hand as it will appear in an im¬
pression. "B" of the same figure, likewise represents
a radial loop on the left hand.
Figure 10 portrays six radial loops, on the right
hand, and Figure 11, six radial loops on the left hand.
Ulnar Loops.
An understanding of the radial loop will always help
you to identify an ulnar loop.
In an ulnar loop the ridges slope downward from
the direction of the thumb toward the little finger;
that is, toward the ulna bone. An ulnar loop on the
right hand, would, in an impression, start as in "C" of
Figure 12, and on the left hand as in "D" of the same
illustration. On either hand it is just the opposite of
the radial loop.
Figure 13 shows six ulnar loops on the right hand,
and Figure 14, six ulnar loops on the left hand.
Figure 10.
LESSON THREE
19
Figure 11.
20
THE SCIENCE OF FINGER PRINTS
•V\ /?•
About sixty-five per cent of all patterns are loops,-
with ulnar loops predominating. You can readily see
the importance, therefore, of being absolutely certain
of your classification of this type. .
The true arch is probably the simplest and easiest
pattern to correctly classify. All of the ridges com¬
posing it have an even, regular trend from one side to
the other, with a slight upward curve in the center.
Figure 15 and 16 show a number of true arch patterns.
Study the patterns of these figures carefully.
Not infrequently the finger print expert encoun¬
ters patterns which are arches but which very closely
resemble loops, and loops which approximate arches.
It is essential that you be able to differentiate between
them.
In some seeming arches a delta will appear. When
such is the case the pattern must be examined very
closely for a recurving ridge. If one single ridge is
found which recurves and passes between the core
(formed in consequence of the recurving ridge) and
delta, the pattern must be classified as a loop and not
as an arch. Figure 17 "A" shows this kind of a loop.
c
z>
Figure 12.
Arches
Figure 13.
Figure 14.
Figure 15.
Figure 16.
LESSON THREE 25
Figure 17.
Recurving ridges will not be found in every case where
a delta appears. Figure 17 "B" is of an arch, contain¬
ing a well defined delta but not any recurving ridge.
Again some arches will resemble loops, on the ground
that they contain recurving ridges. The delta will be
missing, as in "C" of Figure 12. If in Sketch "C" only
a ridge dot or formation of any kind appeared in front
of the diverging ridges "AA" this pattern would be¬
come a loop. It is suggested here that the student re¬
fer to the definitions for loops.
Figure 18 illustrates four Loops approximating
Arches. The top two are Ulnar Loops, right hand or
Radial Loops, left hand and the bottom two Ulnar
Loops, left hand or Radial Loops, right hand. Notice
26 THE SCIENCE OF FINGER PRINTS
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jsä»SÄi--.
-4éÊÊÊiÈÈÈÈk
iMp
imSmm
MPI,'
wËÈKBm
Wimm
Figure 18.
that in each one of these patterns one ridge recurves
between the core and delta. Figures 19 and 20 are
Exceptional Arches because the ridges which appear
to form the deltas run into and form part of the re¬
curving ridge. The fact that the recurving connects
with the delta makes ridge counting impossible and is
the only differing point between the Exceptional
Arch and the Loops illustrated in Figure 18. Study
each of these Exceptional Arch patterns with great
care and get the idea of the ridge formation firmly
fixed in your mind.
LESSON" THREE
27
Figure 19.
Figure 20.
LESSON THREE 29
A few cases will be met where it will be more diffi¬
cult to determine whether a pattern is an arch or a
loop, due to the fact that the recurving ridge will not
recurve very far; that is, it will only make a hook. In
such instances it will be necessary to draw a line, actual
or imaginary, between the assumed core and the delta.
If the recurving ridge touches or crosses this line the
pattern will be a loop. If it does not reach the line in
its recourse the pattern must be classed an arch.
Sketch "D" of Figure 17 is an arch. Here the recurv¬
ing ridge does not pass between the core and the delta.
Exceptional Arch.
Mention has been made that the "Exceptional
Arch" type has recently been adopted as standard.
Under this heading are included all arches or tented
arches containing recurving ridges but no deltas, or
deltas without recurving ridges, a pattern being classi¬
fied as an arch only when all of the ridges composing it
have an even trend. Figures 19, 20 and 22 are Ex¬
ceptional Arches.
Tented Arches.
Tented arches are in reality only a modification of
a plain arch. Tented arches are, as the name implies,
arches in which the ridges are pushed up abruptly in
the center, in the shape of a tent. There is no set rule
or definition as to the dividing line between the plain
arch and the tented arch. Be slow in classifying a
pattern as a tented arch. Unless it is markedly a tent,
classify it as a plain arch. Study Figure 21 which
shows a number of typical tented arches.
Tented arches will resemble loops, and loops tented
arches even more closely than in the case of plain
Figure 21.
Figure 22.
32 THE SCIENCE OF FINGER PRINTS
arches, so examine them carefully for deltas and re¬
curving ridges.
Whorls.
Whorls are finger print patterns in which the
ridges unwind spirally from the center, or in which
the ridges form concentric circles, radiating from the
center or core of the pattern. Whorls are also dis¬
tinguished by the fact that they have two deltas, one
located at the bottom left of the pattern and the other
on the lower right side of it.
There are two general classes of Whorls, the single
and double cored. In the single cored whorls one
ridge unwinds from the center, or else the whorl is of
the concentric circle type. Figure 24 shows Whorls
of both the concentric circle and the unwinding spiral
type. In the concentric circle variety, each ridge
forms a circle or ring about the core or center of the
print. Each ring becomes larger the farther from
the core or center it appears. In the unwinding spiral
Whorls one ridge unwinds from the center, getting
larger at each revolution. These two types of Whorls
are very closely related and sometimes the pattern
will represent the concentric circle around the center
or core and change to the spiral type as the ridges
approach the deltas; or the pattern may begin at the
core as an unwinding spiral and evolve into the con¬
centric circle kind. In the double cored Whorls two
or more ridges unwind from the center, forming a
double spiral. Figure 25 illustrates several double
cored whorls. The double cored Whorl resembles to
some extent the Lateral Pocket Loop and the Twinned
Loop, so watch carefully for the distinguishing char-
LESSON THREE
33
Figure 24.
34
THE SCIENCE OF FINGER PRINTS
Êk
J. -TJl.'-'i=r7-; '
•-j-OU*. ,v*
Figure 25.
LESSON THREE 35
acteristics when you come to study these patterns
later on in this lesson. The paramount principle to
bear in mind in connection with the Whorl is that at
least one ridge must make a complete circle around the
core and the pattern must be possessed of two deltas.
STUDENTS!
Give This Your Undivided Attention.
Again we desire to firmly impress upon your mind
that if you study the foregoing and the following les¬
son—give each the most careful attention of which
you are capable—you will have made splendid prog¬
ress toward learning the entire science of finger
prints. These two lessons, coupled with what you
have already reviewed, actually lay the foundation
upon which your entire finger print education will
rest.
We would not stop here to warn you of this if
we were not anxious to have you pass your examina¬
tions with high honors—if we were not ambitious to
have you wonderfully qualified for the profession you
have decided to follow the remainder of your life.
We would not be content to have you just "skim"
over these lessons. Remember that when you grad¬
uate, and you are asked the name of the finger print
course you took, you will reply :
"THE DUNLAP SCHOOL OF FINGER
PRINTS."
Naturally, then, we want you to be a shining ex¬
ample of finger print perfection. It is this sort of an
impression that helps the Dunlap School to greater
achievement.
36 THE SCIENCE OF FINGER PRINTS
Examination Questions, Lesson Three, Part One.
(1) What are the names of the two fixed points
or termini found in finger print patterns of the Loop,
Whorl and Composite types?
(2) Of what use are the type lines?
(3) When we speak of a ridge "bifurcating"
what do we mean? What do we mean by "diverg¬
ing"?
(4) What are the names of the eight types of
finger print patterns?
(5) Show by an outline how they are divided into
the two groups "Numerical and Non-Numerical."
(6) Without referring" to the text, define or ex¬
plain in your own words what the essential and char¬
acteristic formations are (make a word picture) of
the Arch, Tented Arch, Exceptional Arch, Radial
Loop, Ulnar Loop and Whorl.
(7) Do Arches ever resemble Loops, and if so
in what way?
(8) How many deltas appear in plain loops?
(9) Make a sketch of a Radial and Ulnar loop on
the right hand and a Radial and Ulnar loop on the left
hand, labeling each.
(10) What is the delta?
(11) What is the inner terminus of a loop pattern
called?
(12) How are deltas formed?
(13) What are "type lines"?
(14) If the inner or centermost ridge is a loop or
envelope, where is the core?
(15) What is the rule for selecting the core of a
loop where an uneven number of rods protrude inside
of the envelope ?
LESSON THREE 37
(16) What is the rule when an even number of
rods appear?
(17) Make a sketch of an Arch and a Tented
Arch.
(18) Make a sketch of an Exceptional Arch.
(19) Make a sketch of a Whorl, indicating both
deltas.
(20) (a) What type of pattern appears most
frequently? (b) Which type is most seldom found?
You will receive a credit of five per cent for each
of the above examination questions answered cor¬
rectly.
LESSON THREE
(Part Two.)
COMPOSITES.
Central Pocket Loops.
The central pocket is easily confused with the plain
loop and the whorl. Especial care must be exercised
to separate it from the plain loop or the classifica¬
tion formula will be incorrect, thereby causing a great
deal of trouble when locating that set of prints in the
files at some later date. It is even more important that
you be able to differentiate between a Central
Pocket Loop and a plain Loop than between a Loop
and an Arch. You will realize this for yourself later
on in your studies.
A central pocket loop is a finger print in which
some of the ridges form a regular loop. The loop is
usually bulged at the top. Inside of this bulged part
a small whorl is formed. A central pocket loop being
38 THE SCIENCE OF FINGER PRINTS
of the composite type must have at least two deltas.
Very seldom, however, does one have more than two.
The loop is formed 011 one side of one of the deltas and
must enclose the other delta. The necessary qualifi¬
cation of the central pocket loop is that at least one
ridge must recurve or form a hook inside of the loop,
and pass between the core and the delta formed inside
of the loop at right angles to an axis line drawn
parallel to the general direction of exit of the ridge
forming the loop.
Figure 26 is a sketch of a characteristic Central
Pocket Loop and brings out all of the essential char¬
acteristics this type must possess. In the Sketch, "A"
is the ridge which recurves and passes between the
core "B" and the delta "C," (located inside of the loop
XX) at right angles to the arrow line "D" which is
the axis drawn parallel to the general direction in
LESSON THREE 39
which the ridges forming the loop "XX" leave the
pattern. "E" is the other delta formed outside the
loop. Note that this recurving ridge is circular or
rounded in form throughout.
If the ridge inside of the loop converges instead of
recurves the pattern is a loop, and not a central pocket
loop. By converging is meant that the ridge is angu¬
lar in form where it passes between the core and the
delta. Sketch "A" of Figure 27 illustrates a recurv¬
ing ridge, while "B" shows a converging ridge. Note
the difference very carefully.
7?ectjrV.
7?/c/yi
fo/ires-?*
Figure 27.
Figures 28 and 29 are illustrations of a number of
Central Pocket Loops. Examine each one carefully
and pick out the recurving ridges in the Central
Pocket Loops. Compare with the converging ridges
of the plain Loops in Figure 30.
Whorls will often bear a close resemblance to a
central pocket loop in their general appearance and
shape. The difference is easily determined however.
Trace the ridge forming the apparent loop and note
whether it incloses only one delta. If not the pattern
is a whorl. This point is illustrated in Figure 31 at
end of book. The left hand pattern is a Whorl and the
print on the right side is a Central Pocket Loop.
40 THE SCIENCE OF FINGER PRINTS
|Ü
Hi
álÉHiy
wmmgliä
^ifeälltÄI
Ï^ÂÉKSff
Figure 28.
LESSON THREE
41
Figure 29.
42
THE SCIENCE OF FINGER PRINTS
Figure 30.
LESSON THREE 43
Central pocket loops can be divided into four
standard types, according to the ridge formation about
the core. 1. The recurving ridge may be the inner¬
most ridge formation, an imaginary core being formed
in the center of the hook enclosed by the said recurv¬
ing ridge. See Sketch A of Figure 32. 2. It may also
be formed as in Sketch B of the same figure, or as
previously illustrated. 3. It may be formed by a circle
or by several concentric circles as in Sketch C. 4.
Lastly it may be in the form of an arched line as in D
of Figure 32. By standard type is meant the general
or basic formation. Each ridge need not correspond
exactly in shape and course with the illustrations
given, but still the pattern belongs to one of these
types. You must learn to use and rely upon your own
judgment in classifying them.
x A
&
N C
/ 2>
Figure 32.
44 THE SCIENCE OF FINGER PRINTS
Don't pass over the subject of central pocket loops
until you understand it perfectly. If after conscien¬
tiously studying the text, paying special attention to
details, you do not understand the central pocket loop,
write for additional help, stating just what it is you do
not understand. Further assistance will be very gladly
given in this as in any other matter. We are always
glad to help our students.
Lateral Pocket Loops.
The lateral pocket loop is the second of composite
type patterns. Lateral pocket loops are composed of
two distinct loops. One of these loops must either en¬
velope or surround the other. The ridges about the
core of each loop must terminate or make their exit on
the same side of either delta. (Lateral pocket loops
commonly have only two deltas.)
Sketch "A'' of Figure 33 shows a lateral pocket
loop in which the ridges about the core of each loop
terminate between the two deltas. The two loops are
marked "KK" and "LL" respectively. Both termi¬
nations are on the same or right side of the left delta
and on the same or left side of the right delta. Sketch
"B" of the same figure illustrates a lateral pocket
loop, in "which the ridges of both loops "MM" and
"NN" make their exit on the same or left side of the
left delta and Figure 34 shows both terminations
"00" and "PP" to be located on the same or right side
of the right delta.
In actual patterns the characteristics will not in
every case be as closely and well defined as in these
sketches. That is, both complete loops will not always
terminate entirely on either side. Maybe only one or
LESSON THREE
45
A
B
Figure 33.
46 THE SCIENCE OF FINGER PRINTS
Figure 34.
two ridges of each loop will« terminate on the same
side of the delta. In cases like this the expert must
trace the core ridge, that is, the ridge in the center of
the loop, or the central loop if no ridges appear inside
of it. If two bars or ridges appear inside of the loop,
trace the furrow between the two ridges. Figure 35
shows a lateral pocket loop of this type. Here the
right hand loop is not very clearly defined, but when
the furrow in the center of the two bars, formed in¬
side of the envelope, is traced, the termination is
shown to be on the right side of the left delta and the
other loop clearly terminates on the same side of the
left delta. This feature applies also to the twinned
loops, so bear it in mind when considering that type.
Plain loops will in some instances very closely re¬
semble lateral pockets. They will have the appearance
of containing two loops and consequently two deltas.
LESSON THREE 47
Upon minute examination it will be found that there is
only one well defined loop. In the other one the ridges
forming the supposed loop will not be rounded in form
but will converge or form an angle or point at their
summit. The same holds true in the case of Twinned
Loops so bear this point in mind also when classifying
that type of pattern. Figure 36 shows several illus¬
trations of this. Some of the patterns resemble Lat¬
eral Pocket Loops and others Twinned Loops. The
single circle in each pattern of this figure encloses the
summit of the supposed second loop in which the
ridges converge or come to a point. The double circle
encloses the regular loop and emphasizes how rounded
in form the loop ridges are when they recurve. Par¬
ticular attention must be g'iven to such patterns, as an
incorrect classification of one will change the classi¬
fication formula to such an extent that it would be im-
Figure 36.
LESSON THREE 49
possible to locate in the file the set of prints in which
that pattern occurred, if it should happen to be classi¬
fied otherwise at some later date.
Examine Figure 37. Several patterns of the lateral
pocket loop type are represented. Note the termina¬
tions of the ridge of both loops in each pattern, and
also how well defined and rounded both loops are.
Twinned Loops.
Twinned loops very closely resemble lateral pocket
loops in the fact that they are also composed of two
distinct loops which overlap or surround each other.
Their difference, however, lies in the way the ridge
about the core of both loops terminate as regards the
deltas. In the twinned loop this termination is on the
opposite side of either delta. Figure 38 is a sketch of
a characteristic twinned loop. In this illustration the
ridges forming the loops "DD" and "EE" terminate on
opposite sides of the right delta "X."
If the ridges about the cores of these loops made
their egress on antipodal or opposite sides of the left
delta the pattern would still remain a twinned loop.
Not infrequently whorls resemble twinned loops or
lateral pocket loops; that is the double cored type of
whorls. The differentiating characteristic which
should be borne in mind is that if one of the ridges
of each loop makes at least one complete circuit about
the core before passing outside of one of the deltas
the pattern is a whorl. Figure 39 represents Jwo
whorls of this kind, which resemble twinned loops.
Figure 40 illustrates twinned loops. Study these
six patterns carefully, until you familiarize yourself
with each of the characteristics of which the type is
possessed.
Figure 37.
LESSON THREE SI
Accidental.
There will be patterns encountered at intervals
which do not conform to the definitions or require¬
ments of any one of the nine types we have consid¬
ered. These patterns are usually composed of two or
more of the other types combined or conglomerated
Figure 39.
Figure 40.
LESSON THREE S3
into one design. Sometimes they will have the appear¬
ance of a whorl, penetrated by a tented arch, or two
small whorls enclosed by a larger one, or a combination
of a loop and a whorl, etc. All of these various kinds
will contain at least two deltas, placing them in the
composite group. To these types of patterns is as¬
signed the name Accidental. The Accidental type of
pattern occurs less frequently than any of the others.
It has been estimated that an Accidental will occur in
one of every five hundred impressions examined.
Whenever you meet with a pattern which you cannot
define as belonging rigidly within one of the regular
nine classes, and it contains two or more deltas call
it an accidental. In Figure 41, the left row represents
three characteristic Accidentals. The three patterns
on the right side may be classified as Whorls but are
really Accidentals because there is no ridge about the
core of any that makes a complete circle inside of both
deltas.
You now have a knowledge of the various types
of finger print patterns. In restudving this lesson
study each illustration to which reference is made.
Study it until each point cited is understood. It is
impossible to get the full benefit of the lesson unless
such method of study is practiced diligently and intel¬
ligently. It will be hardest for the novice to under¬
stand certain types like the central pocket loop, the
lateral pocket loop, and the twinned loop, so give
special study to the text relating to these.
Remember, if you need help we are here to help
you. We can teach you, but we cannot learn for you,
so you will have to study diligently, if you should find
it a bit difficult to learn at first.
Figure 41.
LESSON THREE
S
ÉmÈÊm
Figure 23.
THINKING THAT PAYS BIG DIVIDENDS
Thinking does not consist in letting a lot of idle
dreams float through your mind—in letting your
thoughts wander all over "Robin Hood's barn"—in
getting what you read all mixed up with "I wonder
what Nellie is doing tonight"—but in concentrating
your mind upon the subject under investigation.
When you concentrate you must shut out of your
mind all discordant thoughts—all thoughts that do not
56 THE SCIENCE OF FINGER PRINTS
Figure 31.
concern the lesson before you. The lesson which you
have just finished is a very important lesson. The
first part and the second part, examinations for which
of each have been provided, are so all important that
we now urge you to pause and ask yourself : "Have I
thoroughly mastered this lesson ? Do I absolutely un¬
derstand everything included in both parts of this
lesson?
If there is the slightest doubt in your mind go over
this lesson again. The time devoted to re-studying it
will pay the biggest interest imaginable, and it will
help greatly in making of you the splendid finger
print expert we want you to be.
LESSON THREE 57
Examination Questions, Lesson Three, Part Two.
(1) Define the Central Pocket Loop.
(2) Define the Lateral Pocket Loop.
(3) Define the Twinned Loop.
(4) Define the Accidental.
(Answer each of the above four questions in the
same manner as you did question six of part one.)
(5) "What is the difference between a Central
Pocket Loop and a Plain Loop?
(6) Make a sketch of a Lateral Pocket Loop and
a Twinned Loop labeling- each.
(7) What would you call a pattern in which a
Tented Arch was surrounded or super-imposed by two
loops and containing- three deltas?
(8) Make a sketch of a Central Pocket Loop. In¬
dicate the two deltas and the recurving ridge by the
letters x, y and z.
(9) to (20) Classify each one of the following-
twelve finger print patterns as to type. Indicate your
answers to each of these questions by their respec¬
tive numbers as they appear in the examination. In
classifying Loops tell on which hand they would have
to appear to be Radial and Ulnar.
Example of answer form to these last twelve
questions :
9—This first pattern is classified as an .
10—This second pattern is of the type.
Each of the above examination questions answered
correctly will count for five per cent of your grade on
this part of the examination.
58
THE SCIENCE OF FINGER PRINTS
LESSON THREE 61
62
THE SCIENCE OF FINGER PRINTS
CONGRATULATIONS
We offer our congratulations upon your having finished
this lesson—one of the most difficult in the course. A little
later it will seem as simple as A, B, C, and you will wonder
why you considered it difficult, but now this study of finger
prints is new to you and we venture to say you have dreamed
of "bifurcations," "lateral pocket loops," "deltas," "cores,"
and other ridge formations until they became personified and
danced deliriously upon your chest. Well, the worst is over.
In Lesson Four you begin to classify finger prints. You are
told all about the slab of glass upon which the ink is placed
for taking finger prints, the roller you use, the right kind of
ink, the record cards, rolled and plain impressions, and the
symbols that represent the different patterns upon the record
cards. This lesson will be a relief after your arduous studies
of Lesson Three, but it is an indispensable lesson—a great
lesson. It starts you upon the really professional stage of
your career as a finger print expert. It gives you the first
inkling of what finger prints will lead you to as an integral
part of America's colossal scheme of universal identification.
It opens up to you a vista of official service to be rendered by
you in the future—points the way to success in a profession
that is indispensable, but young and not overcrowded.
<£>
LESSON THREE 63
REMARKS ABOUT OUR FREE POST¬
GRADUATE COURSE
In this book we have written in quite a bit of side
talk. Our reason for this is clear : We do not want to
interfere with the straight run of the lessons by inter¬
polating counsel and advice, and yet we believe that
this counsel and advice offers encouragement to manv ;
that it stimulates and quickens ambition and urges the
student to persevere.
That no other school of finger prints "lectures"
its students is known to the faculty of the Dunlap
School of Finger Prints, but the Dunlap School of
Finger Prints is different—is better because of these
"lectures." If you were in college the professor would
have a lot to say to you that you would not find in the
books. In fact he is paid to elucidate and put the zip
and pep into students so they will strive and finally
succeed.
In other words we sincerely want our students to
succeed—want them to graduate with flying colors—
want them to feel secure in the knowledge they have
gained—want them to have confidence in their own at¬
tainment.
It was with this wise thought in mind that the
president of the Dunlap School went a step further
than any other finger print school in rounding out the
course you are now studying. He did this at the ex¬
pense of extensive research and the investment of a
considerable sum of money. This is what he did:
Without any additional cost to the student he
caused a "post-graduate course" to be compiled and
published. This post-graduate course is the final les-
64 THE SCIENCE OF FINGER PRINTS
son in the course—not the fifteenth which originally
completed the course—but the sixteenth. If you
should glance at this finishing lesson now it would
mean nothing in your young life. It would be a jum¬
ble of meaningless symbols, and you would wonder
what it was all about, but when you reach it you will
understand it just as clearly as you now do an invita¬
tion to dinner.
This superlative post-graduate course is added to
make of you a genuine, scientific finger print expert.
It deals with classification, sub-classification, and
those important kinks a finger print expert should
know if he is called upon to operate in a bureau where
there are from five hundred thousand to a million
records.
When we say that it is the work of A. J. Renoe,
head of bureau of identification of the U. S. depart¬
ment of justice, you will know that our boast is not an
idle one. During his years of experience at the federal
bureau in Leavenworth, Kas., where he now has half
a million records and is constantly receiving more,
Mr. Renoe found it necessary to go further than any
of his predecessors in the matter of sub-divisions.
What these sub-divisions are will be taught students
of the Dunlap School, bringing them right up to date
when they go before the world as finger print experts.
What more could anyone ask of a school? "Not a
thing," you will answer and your answer will be cor¬
rect. The Dunlap School of Finger Prints ofifers the
only thorough and complete correspondence course in
finger prints obtainable in the United States or any
other country.
5.
THE SCIENCE
of
FINGER PRINTS
Lesson Four
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Four
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 19'il
by the
Dunlap School of Finger Prints
LESSON FOUR.
Recording Finger Prints.
In the last lesson the student learned to classify fin¬
ger print patterns into various types. In this lesson
he will be taught how to take the impressions in the
proper way.
The standard process used by all bureaus and the
one considered the most practical is the inking of the
fingers from a glass slab on which a thin film of prin¬
ter's ink has been rolled.
The accessories or instruments required for taking
finger prints are a glass slab, a rubber roller, a tube of
printer's ink (job black) and some record cards.
The Slab.
The slab is usually of thick plate glass. There is no
specific rule as to size. A slab measuring four inches
wide, twelve inches long and one quarter inch thick is
conceded by practical workers to be the best. The slab
need not necessarily be of glass. Sheet aluminum,
steel, copper, galvanized iron and tin have been used
with equal success. Just as long as the medium has a
hard, even, polished surface, and retains the ink evenly,
it will do just as well as the glass. The advantage of
the portable glass slab is that the proper ink thickness
can be more easily judged on it, by looking through the
glass. For this and other reasons we have based our
text on its use and have furnished it in our outfit. Be
certain there are no blemishes or any roughness in the
surface of any slab you may use. At all times when it
is not in actual usé, keep it scrupulously clean with
benzine and protect it from dust accumulations by
keeping it ih a' tightly covered box, case, or drawer.
4 THE SCIENCE OF FINGER PRINTS
Speaking again of the proper size; have it large
enough so that all ten fingers can be inked on its sur¬
face, using a different portion for each digit, without
having to re-roll the ink on it. The ink slab should be
placed on a table or support about as high as the elbow
of the average person.
The Roller.
It is of primary importance that a good roller be
employed to evenly distribute the ink on the slab. A
composition roller such as is used by printers is the
very best. This is made of a composition of glue and
molasses. Such rollers should be as wide as the slab
used and about three quarters of an inch to one inch in
diameter. Rubber rollers sueh as are used by photog¬
raphers are equally good. Seam rollers used by paper
hangers are also serviceable. .
Keep the roller clean and away from dust and dirt
with the same care as the ink slab. Do not let the
composition roller rest too long in one place as it has
a tendency to flatten out, especially in a warm tem¬
perature. The roller, like the slab is best cleaned with
benzine.
The Ink.
As has been explained, the ink is practically the
same as is used by printers. Regular printer's job
black ink is a very excellent substitute for regular fin¬
ger print ink. Weather conditions affect the consis¬
tency of the ink a great deal. In cold weather the ink
will be come too thick to spread readily on the slab.
This can be remedied by heating the ink. A less sat¬
isfactory method for thinning but which might prove
useful in an emergency is the adding of a few drops of
LESSON FOUR 5
kerosene. Be very careful not to use too much, or the
print made from it will have a dull gray, blotchy ap¬
pearance.
Record Cards.
There are various forms of record cards in present
use on which finger prints are taken. The card most
generally used, and found unequivocally practical is
the eight by eight inch, stiff, glazed, bristol card. This
is filed vertically in a drawer filing cabinet. In se¬
lecting a card see that it is sufficiently tough in tex¬
ture to stand up under constant handling. It should
have a glazed or enamelled surface, but not so much so
that the ink does not penetrate the surface enough to
make a permanent record. The card should be abso¬
lutely white in color, to facilitate the best photo¬
graphic records being made of it. The clearest carbon
black impression will also result on a card of this type.
Note that the impressions or prints of all ten fin¬
gers are made on each card. The right hand prints
should always be above those of the left hand, and the
corresponding finger of the left hand should always
appear direcly under that of the right. The reason for
this will explain itself when you take up the study of
classification.
The finger print expert should take particular pride
in making impressions of the highest quality. In fact
he should perform this phase of the work in the same
way as an artist would paint a picture or execute a
piece of sculpture. A poor set of prints is a disgrace
to the operator and something which he should not
permit himself to make. The recording of finger
prints has been reduced to so exacting a science that
6 THE SCIENCE OF FINGER PRINTS
anyone with an hour of diligent practice should be able;
to make good clear impressions, which are a credit to
himself and to his profession.
We will first learn how to properly spread the ink
on the slab, preparatory to inking the fingers.
Open the tube of ink, and with a spatula or wood
splinter, dig out enough to cover the end of it, or a dab
about the size of a- coffee bean. Ascertaining that the
slab is perfectly clean and the ink of the proper con¬
sistency, continue by spreading it in various places on
the slab. The amount of ink suggested above is for a
four by twelve inch slab. Grasp the roller firmly, and
roll back and forth over the slab in short motions both
lengthwise and widthways. - Allow the roller to spin
while off the slab at the end of the swing precipitated
by the rolling. This will cause the ink to take hold on
different portions of the slab, and facilitate an easy
and even distribution. After the ink appears to be
fairly well spread, roll the roller across the entire
length of the slab in long even motions. If the slab
is portable hold it up to the light and look through it
from the back. If the film of ink appears a rich brown
in color you have the correct amount on it. If it ap¬
pears a very bright brown, add more ink, and if jet
black remove it by cleaning the roller with a cloth,
then roll same over the slab, removing the surplus ink
from the roller. Repeat until the amount is reduced to
the suitable quantity.
By holding the plate to the light and looking
through it you will be able to see just how evenly the
ink is spread on its surface. -
On a stationary slab, it is impossible 'to tell the
LESSON FOUR 7
proper amount of ink except by the actual process of
making a test print.
When you have the slab properly inked, place it
along the edge of the table or support you are using.
The record .card should be placed to the left of the
slab and along the edge of the table. For practice pur¬
poses no form holder will be needed for the card. Fold
it along the line marking the bottom of the spaces of
the rolled impressions, in that way bringing them close
to the edge of the table. Figure 1 shows what is
meant.
Figure 1.
Rolled and Plain Impressions.
You will note the square spaces covering the upper
portion of. the card are intended for "rolled impres¬
sions." A rolled impression is a finger print made by
rolling the finger from one side of the nail to the
?
THE SCIENCE OF FINGER PRINTS
Figure 2.
B
other, showing a cylindrical projection of it. Figure
2 "A" illustrates a rolled impression.
A plain impression is made by merely pressing the
bulb of the fing'er on the ink slab and then on the card.
Figure 2 "B."
The advantages of the rolled impression as com¬
pared with the plain print are obvious. More ridge
surface is presented in-the former, which is of special
value in making comparisons. Again a rolled print in¬
sures that both terminii, so essential to proper classi¬
fication will be shown. In most plain impressions the
deltas are not reproduced.
Making a Record.
Adjust the ink slab and the finger print blank to the
proper height, about on a plane with the subject's
elbow. Fold the card as previously directed, to facili¬
tate the registering of the prints.
Before inking your subject's fingers, have him (or
her) wash his hands thoroughly in soap and water. Ex¬
amine his fingers to see that they are free from any
foreign substance. It is then well to swab the finger
tips with alcohol (denatured). This closes the pores
LESSON FOUR 9
and prevents oil from accumulating on the fingers
before inking them. It will also dissolve any grease
or dirt that remained after the first cleansing.
Have your subject take a position in front of the
slab, squarely facing it. You as the operator, will take
a position in front of your subject to the left. Grasp
the back of the subject's right hand with your same
hand. Have him extend his thumb in a straight line
with his wrist. Fold or double the subject's remaining
fingers into the palm of his hand and out of the way.
Place the thumb on the inked surface of the slab, over
to one end of it, so that the right side of his thumb
nail is at right angles to the slab. In other words the
plane of the right thumb nail should form a vertical
axis with the horizontal plane of the slab. Figure
3 shows this position. From this posture, roll the
Figure b.
10 THE SCIENCE OF FINGER PRINTS
subject's thumb towards you, over the inked sur¬
face, by turning his hand with your right. Supply the
necessary pressure with your left index finger and
thumb, which should grip the sides of his finger. The
finger should be rolled all the way across the bulb and
over to the left so that the left side of the nail touches
the slab, and again is at right angles to the slab. Ink
each finger as far down as the creases of the first joint.
The ridge surface has now been inked from one side
of the finger nail to the other. Figure 4 shows the
completion of the inking of the thumb.
Figure 4.
Now move over in front of the card. When im¬
printing the thumb pattern on the card, repeat exactly
the same process on the surface of the card as was
used in inking the finger. Roll it from the right side
LESSON FOUR 11
to the left. If just a bit heavier pressure be exerted
on the subject's finger just before starting to roll it,
and when finishing the roll, a squarer, neater and more
regular impression will result. The remaining fingers
of the right hand are taken by duplicating exactly the
same procedure. All the fingers but the one in use
should be kept well turned in or doubled up toward the
palm. Ink and print only one finger at a time.
When making the left hand prints, the operator re¬
mains in the same position, in relation to his subject,
that is, on the left side of him. Grasp his left hand
from your right side and have his arm in front
of y.ou. Start with the thumb again. Place it on
a fresh portion of the slab (with a 4 inch by 10 inch
slab, turn to the other side or edge), with the lefl
side of his left thumb nail at right angles to the slab.
See Figure 5. Roll the finger to the right in the same
Figure 5.
12 THE SCIENCE OF FINGER PRINTS
way as you did with the right hand, until the right side
of the nail is at right angles to the slab. Impress it on
the card in the regular manner. Keep all of the fingers
not in use, out of'the way as described. Repeat with
each digit of the left hand. When printing, be careful
that you get the impression of each finger in its proper
space, and that all important formations are shown.
You have now taken the rolled impression of each fin¬
ger.
On the bottom half of the card you will notice that
spaces are reserved for the simultaneous impressions
of the four fingers from the right and left hand. These
are taken by having the subject extend his indexv mid¬
dle, ring and little finger so that the sides of each touch.
Bend the thumb in towards the palm of the hand as be¬
fore. In this way place all four on the ink slab. See
.Figure 6. When inking exert a slight pressure on
each digit by gentling tapping .the end of it. Bear in
mind that all the four fingers are inked at one time in
one operation. When inked, repeat the process on the
card in the proper space. Do not ink the fingers below
the first joint for these plain impressions. These plain
prints must be impressed simultaneously to serve their
purpose. It is a wise practice although not universally
adhered to, to make a plain impression of the thumb,
by inking it separately and printing it in the arc of the
circle formed by the prints of the other four fingers.
The thumbs must, of course, also be plain impressions.
There are two reasons for taking these plain prints.
Very often one of the rolled prints will be blurred,
while the plain print of the same finger will as a rule
be clearer, thereby aiding in the classification of that
set of finger prints. The second and most important
LESSON FOUR 13
Figure 6.
function they perform is to act as a check on the
rolled prints. That is, to prove they are all in their
proper spaces, or to show that the rolled print of the
right index finger does not appear in the middle finger
space and vice versa. The fact that the plain prints
are impressed simultaneously prevents their being
misplaced and in that way furnishes a check on the
others. The importance of this will become more
significant to you when you begin the study of
classification.
It is wise to include a space on the record card for
a rolled impression of the subjects's right index finger
immediately preceding his signature. This is of legal
value, to attest the signature following.
A good rolled print should be rectangular in form,
nicely squared, and should include all important forma¬
tions. The color of the print should be a light black,
14 THE SCIENCE OF FINGER PRINTS
even in tone throughout. Each ridge should be clearly-
defined and have sharp edges. Figure 7 "A" is a good
print of this kind. Figure 7 "B" is not a good print
of this variety. Too much pressure was applied when
rolling the finger, causing the flat, indistinct, grayish
appearance. Figure 7 "C" is of a print where the
finger was coated with too much ink. In the print of
Figure 7 "D" the blotchy appearance is caused by an
uneven application of the ink on the glass slab. The
blotchy appearance of the print "E" of the same figure
was caused by applying an uneven pressure while
rolling the subject's finger. Study these very care¬
fully and learn your faults by comparison of the prints
you take, with those shown in the illustrations: Strive
to improve. Practice and practice constantly.
Figure 7.
LESSON FOUR 15
When you have finished taking prints, clean your
outfit immediately. Use benzine or kerosene to re¬
move the ink from the slab and the roller. Be sure
to remove every trace of ink from these two instru¬
ments. If the ink is allowed to dry on the slab, the
surface will be ruined when the ink is later removed.
After you have thoroughly cleaned the outfit, put it
away, safe from dust accumulations and ready for fu¬
ture use.
Standard Symbols.
Sir E. R. Henry has assigned symbols to represent
the various types of finger prints. These are consid¬
ered standard and are used universally, as a shorthand
method of description. The marking of the patterns
as to types, by these symbols is the first step of classi¬
fication. On the cards you will note a blank space be¬
low each impression. This is provided for the mark¬
ing of these symbols. Learn the following table
thoroughly. The name of the pattern is given first,
and after it the standard symbol used to designate it.
Name of Pattern.
Symbol.
Arch
A
Tented Arch
T
Radial Loop (right hand)
/
Radial Loop (left hand)
\
Ulnar Loop (right hand)
\
Ulnar Loop (left hand)
/
Whorl
W
Central Pocket Loop
CP
Lateral Pocket Loop
LP
Twinned Loop
TL
Accidental
Ac
Iß THE SCIENCE OF FINGER PRINTS
It will be noted that the radial loop symbols slope in
the same direction as the loop in every case. Learn the
above symbols. Be exact in using them. Do not at¬
tach any letter to them or change them in any way.
Use CAPITAL letters to represent symbols in the
INDEX fingers and LOWER CASE or small letters
in all fingers BEFORE AND AFTER THE INDICES.
The radial and ulnar loop symbols remain the same in
all fingers. Figure 8 is of a record card properly
filled out with prints, and on which the symbols are
F. F. FORMULA—
REF
Figure 8.
LESSON FOUR 17
correctly marked. Study this form carefully and let
it serve as a model for your work.
The Inkless System.
Within the past few years an inkless method has
been devised for taking- fingerprint records. This sys¬
tem is applicable mainly to banks and commercial in¬
stitutions where the objection is raised that the use
of ink is too mussy. Generally only three plain im¬
pressions are taken; one each of the right index, mid¬
dle and ring fingers. This saves time and as no means
of classification is necessary, prints being filed alpha¬
betically by name, it serves the purpose very well.
The prints made by this inkless method are not as clear
as ink prints, and because of this many banks use the
ink in spite of the dirt.
For the information of the student we are includ¬
ing a description of this inkless system, which was de¬
vised by Ray Bauder, a bank clerk. Strips of chem¬
ically pure, lintless, photo blotting paper are saturated
with 3 in 1 oil or any other good volatile machine oil.
The fingers are oiled by pressing them on this oiled
blotter and then on the record card. Lamp black or
powered carbon is dusted or brushed over this oil
print with a camel's hair brush. The black powder ad-
hers to the oil, forming the ridges, developing the print
and causing it to stand out black. In this condition the
print is not permanent and can be destroyed by rub¬
bing. To make it permanent a solution composed of
ten parts of spirits of wine (substitute denatured al¬
cohol) mixed with one part of white shellac and one
half part of sandarac gum is sprayed over the print
with an atomizer. When this dries a hard surface is
18 THE SCIENCE OF FINGER PRINTS
formed over the print. It is thus fixed in much the
same manner as a charcoal drawing.
EXAMINATION ON LESSON FOUR.
(a) Fill three of the finger print cards furnished in
the equipment with finger prints of three persons in
the manner set forth in this lesson.
(b) Mark each pattern in the proper space and
with the exact standard symbol used to describe it.
Mail these to the school for correction. Each part,
a and b, will count for fifty per cent of your grade on
this lesson.
THE SCIENCE
of
FINGER PRINTS
Lesson Five
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Five
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of linger Prints
LESSON FIVE
Primary Classification
It is evident that when a collection of finger prints
attains large proportions, some systematic means
must be provided for indexing, so that they can be
filed and again located on short notice. Indexing by
name would be impractical as assumed names are too
frequently made use of. Some infallible method
based upon the finger print patterns is obviously
necessary.
The primary classification devised by Sir E. R.
Henry serves the first purpose. This classification is
in the form of a numerical fraction, the numbers of
which denote the file drawer in which that set would
be contained.
As explained in lesson three, number values are
assigned to certain types of patterns. Their division
into numerical and non-numerical groups was ex¬
plained in that lesson. Before assigning number
values to the prints of a set, such set must be "paired
off." This pairing off is absolutely necessary before
assigning the number values.
When you have a set of prints for which you want
to determine the primary classification, mark each
pattern with the symbol representing it, as you did
for your examination on the last lesson. Copy these
symbols on another piece of paper, placing all those
of the right hand in a row, each in proper sequence.
Draw a line under them. Underneath this line, write
all the left hand symbols, placing each directly under
the corresponding one of the right hand. You now
RIGHT HAND
1. RIGHT THUM»
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
US
5. R. LITTLE FINGER
LEFT HAND
6. LEFT THUMB
IPâm.-... .
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
Figure 1.
LESSON FIVE 5
have a compound fraction, made with letters instead
of figures. Take for example the set of prints illus¬
trated in Figure 1. In actual work do not forget to
check each rolled print by the simultaneous plain im¬
pressions to make certain that each is in its proper
space. If any print happened to be in the wrong place
or sequence, the primar}- classification would stand a
chance of being incorrect, as would also the sub-classi¬
fication. In the set of Figure 1, the plain impres¬
sions have been omitted. Writing out the symbols
representing the types of these patterns in the form
. A / CP \ W
of a letter fraction ^ j p—^—7 would result.
This letter fraction is then paired off by making a
new one from it in which the numerator, or part above
the line, is composed of the second, fourth, sixth,
eighth and tenth symbols of the unpaired one or
X \ T"[ LP /
- , and the denominator, or part below
the line, consists of the first, third, fifth, seventh and
ninth symbols or —yrryn—rp 7—• Combining
A Cj. \\ 1 Ac
these, or the numerator and denominator we would
/- \ TL LP x
get the new paired off fraction ^ ^. In
other words the numerator of the paired off fraction
consists of the patterns found on the even numbered
fingers or the second, fourth, sixth, eighth and tenth
fingers or the right index, right ring, left thumb, left
middle and left little finger, and the denominator con¬
sists of the patterns from the odd numbered fingers:
the first, third, fifth, seventh and ninth or the right
S THE SCIENCE OF FINGER PRINTS
thumb, right middle, right little, left index and left
ring finger. This pairing is very important, so study
the above text until you understand the operation of
pairing off thoroughly.
After the fraction has been properly paired off the
next step is to assign number values to the various
patterns. In Lesson Three, mention was made that
the eight types of patterns were divided into two
groups, the numerical and non-numerical, and that
this subject would come up again under classification.
This is the place.
Arches, tented arches, radial and ulnar loops, be¬
cause of the frequency with Avhich they occur have no
numerical values in the primary classifications. Com¬
posites, which embrace central pocket loops, lateral
pocket loops, twinned loops and accidentals, are given
exactly the same numerical valuation as whorls.
Whorls and composites when they appear in the
first pair, numerator or denominator, (in the paired
off fraction) are given a value of sixteen. Thus if
a whorl appeared in the right index finger of a set,
which would be the numerator of the first pair in the
1 6
paired off fraction, it would get a value of —— . jf a
composite appeared in the right thumb, or denomina¬
tor of the first pair, it would also get a value of 26-
Combining the two into a pair it would read——. If the
16
right index were a tented arch and the right thumb a
central pocket loop the fraction formed by the first
pair would be ^ et cetera. Whorls and composites
LESSON FIVE
when appearing in the second pair, numerator and de¬
nominator, are given the number value of eight ; in the
third pair, four; in the fourth pair, two; and in the
last pair the value of one. Thus the largest primary
fraction possible would be one containing- all whorls or
composites or a combination of whorls and composites
16 + 8 + 4 + 2 + 1 31
16 + 8 + 4 + 2 + 1 01 31
and would read
Figure
Assigning number values to the set of prints of
is the paired
1 of which
/ \ TL LP /
A CP W T Ac
off fraction we g*et as the result :
First
Second
Third
Fourth
Fifth
pair
pair
pair
pair
pair
0
0
4
2
0
0
8
4
0
1
Numerator
Denominator
The numerator of the first pair is a radial loop and
therefore gets no number value, or zerb. The arch in
the denominator is also given the value of zero. The
numerator of the second pair is an ulnar loop with no
numerical value. The denominator of the second pair
is a central pocket loop and being of the composite
type gets the number value of a whorl, which is eight
in the second pair. The numerator of the third pair
is a twinned loop, and the denominator of the same
pair is a whorl. The twinned loop is a composite, so
both get the value of four, being in the third pair. The
numerator of the fourth pair is a lateral pocket loop.
It gets the same value as a whorl, which is two in the
fourth pair. The denominator is a tented arch with
no numerical value. The numerator of the fifth or
last pair is an ulnar loop and receives no value. The de-
3 THE SCIENCE OF FINGER PRINTS
nominator of the last pair is an accidental. Being of
the composite type it gets the value of a whorl or 1.
Adding up the numerator values, also the denom¬
inator values and placing the result in the form of a
regular arithmetical fraction we get as a result
0 + 0 + 4 + 2 + 0 which equals 6
0 + 8 + 4 + 0+1 13
The One Over One Fraction.
As has been stated, a set of prints composed en¬
tirely of whorls or composites, or a combination of
whorls and composites, will have the hig+est value, or
31
On the other hand a set composed entirely of
31
loops, arches and tented arches or their combinations,
will not have any numerical value at all. In order to
have a place irqthe files for a set of prints it must have
a numerical value. Therefore an arbitrary fraction or
a value of — is given to a set composed of all first
group patterns. When this is done the —— fraction
must be added to every set of prints, otherwise sets
containing a different number of whorls, in different
positions in a set will have the same number value.
\ \ \ \ \
/ / •/ W W'
would be ^ ^ ^ / Z, assigning number values
\ \ \ / W
0 0 0 0 1 ,1 • »
equal ——, or the same as given to an all
For instance a set reading y Paired off
00001 1 1
loop or first group set. Remember therefore, that the
LESSON FIVE Ü
fraction —j— is added to every set, to get the primary
classification. In the set in Figure 1, which we took
as an example, Ave got ^ as the sum of the number
-L O
values. In order to get the primary fraction for this
set of prints, we would have to add the fraction—j—
which would give as a result plus -j—equals-^—. In
13 1 14
1 31 32
an all whorl set we would add —y- to yy, obtaining
as the highest primary classification possible.
As there is a possibility of one fing'er having one of
two types of pattern, that is, a numerical type, all ten
fingers can have any one of two, to the tenth power,
(2'") in other words 2X2X2X2X2X2X2X2X
2X2, or 1,024 combinations. Thus we have 1,024
different primary classification fractions possible un¬
der the Henry system of classification.
Occasionally it is handy to be able to tell what fin¬
gers of a set contains loops and which whorls, when
all you have to work from is the primary fraction.
This can very easily be done. All that is necessary is
to work the process in an opposite manner. For in¬
stance if we have the primary classification fraction
13 1
-the first step is to subtract the regular — fraction,
19 1 1
12
leaving . Eig-ht and four are the only numerical
18
values assigned to whorls which, when added up give
twelve for the result. Likewise sixteen and two are
10 THE SCIENCE OF FINGER PRINTS
the only two numbers which give 18 in the denomina¬
tor as the result. As eight is the number given to
whorls in the second pair, and four the third pair, we
08400
get for the numerator and -
for the denominator, or ,> ^ 1 2 2 for the com¬
ió 0 0 2 0
pound numerical fraction. Substituting the letter "L"
for the first group patterns and "W" for the second
L W W L L r . , t rr
group patterns we get — tor the paired off
VV J—/ -L/ VV -Lv
fraction. As the numerator of this paired off frac¬
tion consists of the second, fourth, sixth, eighth and
tenth digdts or fingers and the denominator the first,
third, fifth, seventh and ninth fingers, the transposed
fraction showing each print in its natural order will
read JtV V \\ Therefore the right thumb and
W W L L L
right ring finger, left index and left middle finger pat¬
terns are of the numerical type and the rest are of the
first group type.
Examination on Lesson Five
Work out the primary classification for the let¬
tered fractions of Questions 1 and 2. The symbols
composing these lettered fractions represent the
prints as appearing in their natural sequence. You
must pair them off before assigning number values.
m A \ CP W T
1 ' TL Ac LP X /
W / T CP \
■ ' T A X TL Ac
LESSON FIVE 11
(3 & 4) With the equipment fill two cards with
prints in the regular way. Mark each print with the
symbol and work out the primary classifications.
Place the resulting fraction in the space marked "F. P.
Formula," using the line following the words, as the
dividing line of the fraction.
(5) Convert the primary classification fraction
19
back to the un-paired symbol fraction by the method
explained on pages 9 and 10.
Your answer to each question will count for 20 per
cent of your grade.
THE SCIENCE
of
FINGER PRINTS
Lesson Six
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Six
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1922
by the
Dunlap School of Finger Prints
Revised Edition
LESSON SIX
Latent Finger Prints
A latent finger print is one found on some smooth,
even surface. It is left by the oil or sweat on the
ridges of the finger tips. When the fingers are
brought into contact with a smooth surface, such as
a piece of paper, furniture, woodwork, windows,
metals, etc., the oil supplied to the ridges by the ducts,
adheres to that surface touched, leaving a reproduc¬
tion of the pattern formed by these ridges. It is called
a latent print because it is composed of a colorless oil
and is therefore invisible to the naked eye in the
ordinary meaning of that expression.
Closely allied with latent prints, and prints which
can well be included under the same heading are those
left in blood, paint, or any colored liquid, prints im¬
pressed on soft paint, wax, etc. In murder cases prints
left in blood are many times found. Blood is the best
printing medium known, so make careful examination
for such prints in any crime involving violence.
Value of Latent Finger Prints
Latent finger print impressions left at the scene
of a crime serve to identify and fix the guilt of the
perpetrator. Such impressions are taken to the files
and a duplicate sought for. If there is no duplicate in
the local files, such prints can be sent to other identi¬
fication bureaus throughout the country in an at¬
tempt to locate a duplicate. If some one is suspected
of the crime, that person's finger prints can be taken
and compared with the latent impression. Otherwise
i THE SCIENCE OF FINGER PRINTS
keep the latent prints found on file so they can be
compared with those of any suspects that are appre¬
hended from time to time. Innumerable crimes that
at the time of commitment seemed obvious mysteries
have been solved in this manner.
How to Look for Latent Prints
In looking on an object for a print, use if possible,
a hand magnifying glass. Keep your eyes some dis¬
tance from the object and examine the surface from all
angles. A latent finger print to be visible to the naked
eye must be viewed at a certain angle. The light
striking the globules of oil composing the ridges of
the latent print should be reflected into the eye. That
falling on the furrows or between the ridges should
be reflected past the eye. On small articles where the
expert has a well founded suspicion that prints exist,
but where they cannot be seen it is well to treat the
entire surface of such an object with the proper chem¬
icals as will be explained later on in this lesson.
Latent finger prints, left accidentally as they are,
will of course not be as clearly defined as finger prints
on a regular record taken with ink and under the hest
of conditions. Often only a portion of the ridge pat¬
tern will be found and even that so indistinct as to be
barely discernible. Llowever, as long as the core or
the delta and five or six additional characteristics are
plain enough to be seen, the print will serve for iden¬
tification purposes. Cases are on record where con¬
victions have resulted from finger print evidence
where only five characteristics or points of compari¬
son could be indicated.
Sir Francis Galton selected five types of ridge for-
mation to be used as characteristics in the comparison
of finger print patterns for identity. These five for¬
mations he named, 1, bifurcation; 2, ridge dot; 3, short
line ridge; 4, abrupt ending; 5, island. The names
describe or define fairly well each formation. A bi¬
furcation is a ridge which forks or splits in half, each
fork continuing as a separate ridge. A ridge dot is a
very short segment of a ridg'e. It is about as long as
it is wide, appearing in the print as a dot or period. A
short line ridge is a slight prolongation of the ridge
dot. It is a ridge which has its source and end within
the pattern. An abrupt ending is, as its name implies,
a ridge which stops suddenly, having its end or ter¬
mination inside of the pattern. The island is formed
in consequence of a ridge bifurcating, the two forks
again uniting into a single ridge. Figure 1 illus¬
trates these five formations. The same character¬
istics are used today for purposes of comparison.
Therefore, when determining if a latent finger
print will be of any value or not, look for the appear¬
ance of any or several of the characteristic formations
just described. The bifurcation and abrupt ending is
most common. Remember that a latent print should
possess at least five bifurcations or five abrupt end-
2
1. Island.
2. Bifurcation
3. Abrupt Ending
4. Short Line Ridge
5. Ridge Dot
Figure 1
G THE SCIENCE OF FINGER PRINTS
ings, or better still, a combination of one or more of
the several characteristics, to warrant bothering with.
Of course, if you find two or three prints which by
their arrangement appear to be from the same hand,
and they have five or six of these characteristics col¬
lectively, they are just as valuable as one print with
that many points of comparison.
Smudges
Right here it is well to learn what "smudges" are.
Smudges, as the name implies, are smeared finger
prints. As applied to latent impressions, they are
those which show no ridge formation and result from
the fingers being drawn over the surface with which
they come in contact. If you come across a smudge
when searching for latent impressions at the scene of
a crime, do not bother or waste time trying to de¬
velop it.
Where to Look for Latent Prints
The principal and usual crimes involving the use
of latent finger print impressions, are those having to
do with robbery, murdering and blackmailing.
"Robbery" in the common sense of the word means
unlawfully entering private premises and removing
articles of value. The finger print expert when called
upon a case of this nature should follow certain plans
of procedure in searching the scene of the crime for
possible latent finger prints.
We will suppose that you are actively engaged in
the profession and have just been called upon to ren¬
der your services on a robbery case.
Before proceeding to the scene of the crime in-
LESSON SIX Ï-
struct the officers upon the premises to keep their
hands off all articles close to the scene of crime. Also
instruct them to keep all other persons away. This is
important because some outsider may unconsciously
or intentionally blur or smudge all the finger print
evidence that might have been found. The public is
usually morbidly curious whenever a murder or rob¬
bery occurs, and if allowed, will go about picking up
and examining everything in sight. To prevent any
evidence being destroyed in this way always see that
the above precaution is carried out.
The logical and only systematic plan on which to
conduct your search for latent prints is to place your¬
self in the position of the robber. First direct your
search around the door, window, transom, etc., where
entrance was gained. If you were entering the prem¬
ises in the same way where would you place your
hands? If a door or window has been jimmied, search
around the sash, the panels of the door, and the glass
surface of the window. If there is a smooth brass or
enameled knob on the door and the entrance is one
that is seldom used, it is well to examine the knob for
latent finger prints. If a pane of glass has been
broken to gain entrance, examine each fragment that
has been removed, also any pieces that might still re¬
main in the sash. If entrance has been made through
a window located some distance up from the ground,
examine the outer window ledge, and bottom of the
inner window ledge, very carefully, as it is quite likely
the robber placed his hands in both places when lifting
himself up. Remember that only smooth surfaces will
show useful latent prints. Do not waste time examin¬
ing rough wood or metal surfaces. Not infrequently
3 THE SCIENCE OF FINGER PRINTS
you will find palm impressions as well as finger prints
and the ridge formations of the palm will often re¬
semble arches, loops and whorls, so you must be very
careful not to confuse a portion of a palm print for a
finger print. They are distinguishable in that a palm
impression will show a very slight curvature of the
ridges as compared to a finger print. This is because
of the much larger skin surface of the palm as com¬
pared to that of the finger. In Lesson Ten there is il¬
lustrated a latent palm impression. Take careful note
of it as compared with the finger print when you come
to that lesson.
Determine, from the owner whose premises have
been robbed, whether any pieces of furniture or fix¬
tures have been moved from their accustomed places.
If so, examine all such articles very carefully for latent
finger prints. Sometimes the robbers will remove
electric light bulbs, in order to attach electric drill
sockets, that is, when safes or strong boxes are to be
opened; light bulbs are also sometimes removed and
replaced in order to get better light to work by.
Therefore it is a good policy to examine all the electric
light bulbs for latent finger prints, especially when the
robbery has been perpetrated during the night and
light was necessary to do the work. If a bulb is mis¬
sing from any socket, make a careful search for it as
the chances are strong in your favor that it will con¬
tain some good impressions. If any tools have been
left by the robbers, as would be likely if they made a
hasty exit, examine same carefully. And lastly, if exit
was made by some different way than the robbers en¬
tered, proceed to look around such exit for latent
prints in the same way you did the entrance.
LESSON SIX 9
In cases involving premeditated homicide, proceed
with the investigation as for robberies, that is, in the
manner just outlined. Murder cases of this kind are
more likely to yield good latent finger prints for sev¬
eral reasons. The person or persons committing the
assault will be nervously pitched up to a high strain of
excitement. This condition causes an excessive flow
of perspiration. The more perspiration the better
will be the latent finger prints left. Also, persons
about to commit such a misdeed have nothing but the
thought of its accomplishment in mind. They will
therefore go about touching and handling objects pro¬
miscuously. Again, murders or assaults often result
in profuse bloodshed, and blood is the best finger print
ink obtainable. Furthermore, this type of criminal
sufifers a mental reaction akin to abhorrence, the mo¬
ment his purpose has been accomplished. His first
subsequent thought is to get rid of the instrument of
death. This is usually dropped on the spot before the
perpetrator flees from the scene. When you are in¬
vestigating a crime of this nature, look for the
weapon. Whether a club, knife or revolver, there is
likely some spot on it which will disclose a valuable
finger print impression.
Another kind of crime involving finger print in¬
vestigation is blackmailing. This type of crime is di¬
rected at both the poor and rich. Anonymous letters
are sent demanding payment of certain sums of money
upon penalty of various dire results. The anonymous
communications should be examined for latent finger
prints. Recently the head of a large lumber company
in Tennessee received such a black-hand letter threat¬
ening destruction of his lumber yard by fire unless a
10 THE SCIENCE OF FINGER PRINTS
fabulous sum of money was forthcoming. Along
with the letter came a photograph of a burning lum¬
ber yard with the inscription typewritten below ''This
is a sample of our work." In pulling the photograph
from the typewriter, however, the blackmailer
thoughtlessly left a latent impression of his thumb on
the front of the paper and one of his index fingers on
the back, in the upper right hand corner. Lieut. Paul
Waggener of the identification bureau in the police
department of Memphis, found these impressions and
caught the guilty party before any damage had been
done.
The foregoing three classifications cover in gen¬
eral, the uses of latent finger print impressions in
solving crime. Of course, each case the finger print
expert is called in on will require an individual appli¬
cation of his own good judgment. The thing to bear
in mind is what objects were likely to have been
touched by the perpetrator and then to carefully ex¬
amine such objects for prints.
If latent finger prints are found on some object
which is of no great value, it is a good idea to cut the
piece containing the print out, or if the object is not
too large, to remove the. whole thing to your office.
You can then work on it in privacy and under better
conditions.
Always work in private on your prints if possible.
When other persons are moving about and distracting
your attention you cannot of course give your best
efforts to your work. Plave two witnesses present
when you make the exposure for the photograph of
the print, to testify as to its genuineness in court.
LESSON SIX ]I
Development of Latent Prints
Latent finger prints as found on an object are prac¬
tically invisible to the naked eye, and useless in that
state for purposes of comparison. To bring them into
view, they are developed. Various means and methods
of development are employed. Each of the methods
taught in this lesson is fitted for a special purpose.
Therefore if you are going to develop a latent print on
a piece of paper use the method described as best
suited for development on paper. If the print is found
Figure 2
on wood, glass, iron, steel, plaster, etc., use the
methods recommended and taught for each case.
The use of powders is the ordinary method em¬
ployed for developing latent finger prints on wood and
metal objects. On light surfaces, such as white
enamel, light wood finishes, gray paint, etc., a black
12 THE SCIENCE OF FINGER PRINTS
powder, usually lamp black or powdered carbon, is
used as the developing agent. A fine quill camel's
hair brush, called a striping brush, such as was sent
you with the finger print outfit, is dipped into the
powder, picking up a small amount on the hairs. The
print is then yery lightly brushed or dusted over with
the powder on the brush. See figure 2. The small
granules will adhere to the oil forming the impres¬
sion of the ridges, thereby causing the pattern to stand
out in contrast to the surface upon which it appears.
The development of latent finger prints is a delicate
task. It requires a very great deal of practice before
the expert will become proficient. Use a very light
circular motion when brushing. The tips of the hairs
on the brush should barely touch the surface. Use
the very least amount of powder possible. The novice
will always want to use more and more powder be¬
lieving he can improve the results and cause the im¬
pression to stand out more clearly. This procedure
is fatal to the print. Only a limited amount of powder
can adhere to the oil of which the latent print is com¬
posed. When more powder is applied after this limit
has been reached the result is that the powder which
had adhered originally and become partially dampened
from absorption by the oil, is swept along by the ex¬
cess powder, thereby smearing the whole impression.
Some schools advocate various methods for
spreading the powder over the latent print other than
using a brush. Practice, however, has proven beyond
the shadow of doubt, that the developing powder is
best distributed with a quill camel's hair striping
brush like the one you received with your finger print
outfit.
LESSON SIX 13
Prints left on glass or any transparent surfaces
are best developed with aluminum lining powder.
The aluminum powder is metallic and will form an
opaque surface on the print. This will permit of a
good photograph being taken. We advocate in cer¬
tain cases, the use of aluminum powders on wood and
metal surfaces also, as it adheres better to the oil and
by reason of its fineness a smaller amount may be
used. The smaller amount being lig'hter, a latent print
will not as likely be destroyed when brushing.
Always select a powder, the color of which is in
strong contrast with the surface upon which the print
is found. This will make it more visible and better
photographs can thus be taken.
Prints found on paper are best developed by using
chemicals.
As paper reflects the light so strongly, it is usually
very hard to locate a latent print on the surface of
it by a mere optical examination or search. Some¬
times, however, foreign substances, such as dirt, dust,
colored matter, oil or grease, have been present on the
fingers of the person leaving a print. This dirt will
show on the paper and indicate the location of the
print. If no trace of a print can be found and the
suspicion is strong that prints are actually there, the
entire surface of the paper should be chemically
treated as explained in the following paragraphs.
The best developer for latent prints on paper is the
action of ammonium sulphide fumes on lead acetate.
Pulverized lead acetate, commonly known as sugar
of lead (white in color), is dusted or brushed over the
latent print the same as black or white powder. Com¬
mercial lead acetate, such as you will buy, invariably
14 THE SCIENCE OF FINGER PRINTS
comes in crystal form. These crystals are very small
and fine and look like tiny flakes. You must reduce
these crystals to powder before using it to develop a
latent print. This is easily done by shaking a small
amount from the bottle or container onto a sheet of
white paper. Place another sheet of paper over it and
proceed to rub the chemical between the two, until it
has been reduced to a fine powder. The paper con¬
taining the powdered latent print is then held, print
side down, over a dish containing ammonium sul¬
phide. The fumes of the liquid act upon the lead
acetate, turning the lead to the metal form, and bring¬
ing the print out a dark brown in color. Where the
location of the prints cannot be determined the whole
paper is treated in this way.
Lifting Developed Latent Prints
Finger prints after they have been developed, can
be lifted from any solid object upon which they might
appear, such as glass, wood or metal. This is useful in
obtaining a permanent record of a finger print from
immovable objects. The lifting of such prints is ac¬
complished by means of a sheet of gelatine. A square
large enough to cover the print to be lifted is moist¬
ened on one side with sufficient water to make it ad¬
hesive. Do not wet the gelatine too much and be
very careful that no drops of water gather on the sur¬
face of the film. It should be dampened only enough
to make it sticky. Place this gelatine, moist side
down, over the developed print. Secure perfect ad¬
hesion by pressing on the back of it, using a blank
piece of paper over the gelatine to keep it clean. Let
it remain for a moment, then peel it off, starting at
one corner. The powder which adhered to the oil
LESSON SIX 15
forming the ridges of the latent print will stick to the
gelatine, transferring the pattern to it. Use as much
powder as possible in developing a latent print that is
to be lifted. The aluminum powders will give the
best results. It is difficult to lift developed latent
prints successfully, and it will require practice to make
you proficient in this phase of finger print work.
The most successful finger print experts do not
develop a latent finger print immediately. Latent
finger prints are sometimes destroyed by brushing
powder over them. Once destroyed they lose all their
value, and can never be restored. Never take a chance
of destroying a print, therefore, until you have made
a permanent record of it. The finger print science has
advanced marvellously in the past ten years and finger
print experts have now learned how a photograph can
be taken of the latent print by a certain amount of
manipulation with the camera and light. This sub¬
ject of finger print photography is covered and fully
taught the student in Lesson Ten. Probably this
record will not be as clear as a photograph made of
the same print after it has been developed, but never¬
theless you have a permanent record. After the pho¬
tograph has been taken of the undeveloped print, de¬
velop it with the powder. Then make another photo¬
graphic record of it. Lastly, you can lift the print
with the gelatine film transfer. Thus you will have
three records of it. At least one of which will be good.
Fixing Latent Prints
In some cases, depending entirely upon the cir¬
cumstances, it is advisable to produce the developed
latent finger print in court, upon the object it was.
found. This necessitates fixing it on that object so it
16 THE SCIENCE OF FINGER PRINTS
will not easily be rubbed off. A solution composed of
ten parts of denatured alcohol, one part white liquid
shellac, one half part sandarac gum mixed together
and sprayed over the surface of the developed latent
print through an atomizer will make it permanent.
When spraying this solution over the print, hold the
atomizer at least a foot away from it and spray in a
horizontal plane. Do not apply too much solution or
it will run, and destroy the print. This solution when
it drys, forms a hard transparent coat or surface over
the print, protecting it from destruction by rubbing.,
Length of Time a Latent Print Will Last
The question has been raised ars to how long a
latent finger print will last before drying up and dis¬
appearing. When acting as an expert witness on the
stand, the opposing attorney will often ask this ques¬
tion. You must be able to answer him. There is no
set time as to how long one of these latent impres¬
sions will be useful. The minimum time is set as forty-
eight hours. The life of a latent finger print is de¬
pendent on temperature, humidity of the air, exposure
to the elements, friction caused by contact with other
objects, also the amount of oil composing it. Being
made up of oil, which evaporates very slowly, they
will usually last for some time. On glass, latent finger
prints have been known to be visible for months, even
long after they have dried up. It seems that a film
will form over the surface, keeping the air from the
oil underneath. This is assigned as the reason for the
length of visibility in these instances. Of course one
of these prints, while it may be visible, can not be de¬
veloped. This is because of the dry film which has
formed over its surface. If a record of an old print
LESSON SIX 17
like this is wanted, photography is the best method of
securing such record. Sometimes if a warm iron is
held on the surface of it, the dry covering film will
soften sufficiently to enable the expert to develop it
with powder. If you are asked the question in court,
relative to the life of a latent finger print, review the
above data to the questioner.
The Elimination Process
If you are successful in finding several latent fin¬
ger prints at the scene of a crime where robbery has
been committed, ascertain who was privileged or auth¬
orized to handle the safe or container of the stolen
articles. Take the finger prints of such persons and
by comparison of these prints with the latent prints
found, eliminate those of all persons who had rightful
access to such container. In this way you can deter¬
mine how many outsiders worked on the job and get
at the actual prints which will be of value to you.
For example, we will suppose you were called upon
to investigate a burglary where an office safe had been
broken open and securities stolen from it. There
were six persons employed in the office but only three
had lawful access to the safe. We will further sup
pose that your investigation had disclosed five laten,
impressions on the outer door of the safe and four
prints on the inner door. Your next step would be tr>
take the finger prints of the three persons having ac¬
cess to the safe, for elimination purposes. That is,
you would take these finger prints and compare then-
with the latent prints you have found. If any of the
latent prints were identical with any of the prints you
had taken, you would know that they were place®
there in the course of duty and had no bearing on th-"
18 THE SCIENCE OF FINGER PRINTS
crime. If one of the prints on the outer safe door
was a whorl and compared with a whorl on the inner
safe door and both of these compared with the whorl
on the rig-ht index fing'er of an employee authorized
to go into the safe, you would eliminate those two
latent prints as having no value in the solution of the
crime. If you found that three more of the impres¬
sions on the outer door and one more on the inner door
compared with the prints from fingers of the other
two employees, you would then direct your attention
at the remaining print on the outside door and the two
remaining impressions on the inner door. If these
three prints were unlike, then all three would be re¬
corded and preserved for purposes of apprehending
and identifying the guilty party. The advisable
course to take next would be a comparison with the
prints of the remaining employees who had no right
to the vault. In this way, you could determine
whether it was an inside job or not. If it was an in¬
side job, perpetrated by one or more of the employes,
your case would be solved there and then; otherwise,
you would be in a position to proceed intelligently
with your work.
Always Have Your Outfit Available for Instant Use
Always have your complete finger print outfit
available for instant use. You may be called on a case
any moment and should therefore be prepared to pro¬
ceed immediately. In every case be prepared with a
complete set of equipment to make a thorough and
perfect investigation. It is most embarrassing and dis¬
tressing to find that you have left your black powder,
your camel's hair brush, your magnifier or your gela-
LESSON SIX 19
tine transfer at the office after you have reached the
scene of a crime and started your investigation.
Theory of Crooks Wearing Gloves Discredited
Many are under the assumption that gloves are
worn by persons while perpetrating a crime. This is
an erroneous impression and very seldom the case.
In the case of a murder or assault, revenge is many
times the motive. Thus the criminal has nothing in
mind but the accomplishment of his desire. The idea
of finger prints will never enter his mind. In cases
of robbery, such as are perpetrated by professional
yeggs, much delicate work is necessary, and they can¬
not allow themselves to be hampered by wearing
gloves merely to prevent leaving finger prints. So if
anyone should advance the theory of crooks wearing
gloves, you will know what to tell them.
Practice! Practice! Practice!
When you have finished the study of this lesson,
you will find yourself unconsciously looking around
for latent finger print impressions on every object that
falls under your observation. This is fine practice.
Keep it up. When you do encounter a latent print,
and the circumstances permit, develop it and experi¬
ment lifting with the gelatine transfer. All the prac¬
tice of this kind you can squeeze in will be of invalu¬
able help later on when you begin working on actual
cases.
You should experiment extensively on developing
and lifting latent finger prints by the methods de¬
scribed in this lesson. In order that you may secure
the necessary paraphernalia there is appended a list
20 THE SCIENCE OF FINGER PRINTS
of all the articles you will need, with the source of
supply. The cost is small.
Lamp black—Any paint store or Devoe & Rav-
nolds, 14 West Lake street, Chicago.
White talcum (unscented)—Any drug store, or E.
R. Squibb & Sons, 111 North Market street, Chicago.
Gold and silver aluminum lining powder—Any
paint store or Devoe & Raynolds (address above).
Lead acetate—Mr. Franzak, Gazzolo Drug and
Chemical Co., 119 So. Green Street, Chicago.
Ammonium sulphide-—Same source as for lead
acetate. (Note: This chemical should be in liquid
form.)
Examination Questions on Lesson Six.
(1) What is a latent finger print?
(2) Of what value are latent fing'er prints?
(3) How are latent prints on glass developed?
(4) What color powder would you use on a dark
surface?
(5) How would you develop a print found on a
sheet of white paper?
(6) What should be done to obtain a permanent
record of a print before developing it?
(7) Why should not a print be developed imme¬
diately upon being found?
(8) What determines the life of a latent finger
print?
(9) Tell why the theory of crime perpetrators
wearing gloves when committing a crime may be
wrong.
(10) Lift a developed latent finger print impres¬
sion from some solid object of wood, metal or glass
LESSON SIX 21
with the gelatine transfer. Attach to your examina¬
tion paper and send to the school with the answers to
the other nine questions.
Note—Your answer to each question will count
for ten per cent.
STUDY THAT PAYS BIG DIVIDENDS
You will agree that this lesson has proved so ab¬
sorbingly interesting as to command your undivided
attention. It is the phase of finger print work taught
in this lesson that has caused the average layman to
believe the Finger Print Science a subject enshrouded
in mystery. It cannot be denied that there is some¬
thing akin to magic in finding, developing and lifting
latent finger print impressions at the scene of a crime
and then through that little mark bringing the un¬
known guilty person to justice.
There has always been an acute shortage of finger
print investigators really proficient in this particular
branch of the work. The reasons for the shortage
are natural. The Dunlap School of Finger Prints has,
in Lesson Six, for the first time comprehensively
compiled and arranged this information in printed
form and made it available to the expert and student.
Then again, it requires a little more patient practice
to g'et the knack of the work than the average man is
willing to devote. Let us remind you here and now
however, of the fact that the price of any article or
service is based upon the supply as compared with the
demand. Because of the scarcity of finger print in¬
vestigators expert in latent finger print work, they
are in such demand as to render their services very
22 THE SCIENCE OF FINGER PRINTS
valuable. It is usual to pay them twenty-five dollars
a day besides expenses. You can therefore readily
realize the advantage and desirability of learning
Lesson Six from "a" to "z" and to practice searching,
developing, and lifting latent prints at every oppor¬
tunity you have. Every minute you spend practicing
will, when you are actually engag'ed in the profession,
prove an investment paying constant returns in
amounts far beyond your expectations.
LESSON SEVEN
In the next lesson we go back again to classifica¬
tion. In Lesson Five you learned how to work out
the primary classification used in filing away finger
print records. When a bureau accumulates a large
number of finger print cards, there will be many hav¬
ing the same primary classification. It therefore
becomes necessary to further divide and arrange the
records by means of sub-classifications. It is this
subject of sub-classification that you are taught in
Lesson Seven. With this lesson you have finished
almost half the course and the goal is in plain sight.
The rest of the way is smooth sailing. Before you
have time to realize it, you will be standing on the
threshhold of your new profession, prepared and
found ready to step in and take your place among
those who are now reaping- the rewards of their study.
THE SCIENCE
of
FINGER PRINTS
Lesson Seven
i'-.r. --'j - "!■ 1 ,
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Seven
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 192 2
by the
Dunlap School of Finger Prints
LESSON SEVEN
The Lettered Sub-Classification.
When a collection of fingerprint records attains a
large size, fifty thousand cards, for instance, there
will be several sets which will have the same primary
classification. To facilitate rapid search of the files for
duplicates it becomes necessary to break up these pri¬
mary accumulations into smaller groups. This is done
by sub-classification.
The sub-classification is composed of a fraction
much like the primary, only it is made up of letters in
the form of symbols describing certain patterns.
The sets of prints were paired off to obtain the
primary classification. In the sub-classification they
remain in their regular order. The prints from the
right hand as they appear, in natural order, form the
numerator, and those of the left hand the denominator.
A set of prints having arches, tented arches, radial
or ulnar loops or combinations of these patterns in
both index fingers, with arches, tented arches or radial
loops appearing in any one or more of the remaining
fingers will have a lettered sub-classification. In¬
cluded with the lettered sub-classification are the four
loop sub-classifications resulting in sets having ulnar
or radial loops in both index fingers, or an ulnar loop
in one index with a radial in the other, and where no
arches, tented arches or radial loops precede or fol¬
low the index fingers. No whorl or composite should
■appear in either index finger. Just as soon as one of
these do, the lettered sub-classification is eliminated.
Arches, tented arches, radial and ulnar loops when
4 THE SCIENCE OF FINGER PRINTS
they appear in the index fingers of a set of prints
which will have a lettered sub-classification are desig¬
nated by a capital letter "A," "T," "R," or "U" in the
sub-classification formula. Thus, if in a set of prints,
the right index finger was a radial loop and the left
index a tented arch, they would be shown in the
R
formula as —, the right index finger forming the
numerator and the left index the denominator, the
numerator symbol appearing directly over that of the
denominator, always.
Arches, tented arches and radial loops when they
appear before or after first group patterns in the index
or first fingers of each hand, are represented in the for¬
mula by small, or lower-case letters, namely : "a," "t"
and "r," appearing before or after the index finger
symbol, either in the numerator or denominator, de¬
pending upon whether it came from the right or left
hand.
Note : The ulnar loop is not considered in the let¬
tered sub-classification when it appears before or
after the indices. This is because of the frequency
with which it occurs, about sixty-five per cent of all
finger prints being ulnar loops. Therefore a set of
, • , , , x • \ \ \ \ \
prints having the symbol ti action / / / /—>
U
would be sub-classified ^7 '
Take for example the set \ /^ t'
tered fraction the numerator represents the right hand
prints and the denominator the left hand prints. As has
previously been mentioned this is the proper order for
the sub-classification. We also learned that the in-
LESSON SEVEN 5-
dex fingers are the first to be taken into consideration.
One is a radial loop and the other an ulnar. We are
thus sure that this set will have a lettered sub-classifi¬
cation, as no whorls or composites appear in either
index. Writing out the classification formula by ex¬
hibiting the symbols of the index finger patterns in
capitals, we get —. Next looking for arches, tented
arches and radial loops before and after the index, we
direct our attention to the right thumb. It being an
ulnar loop and appearing before the index finger is not
considered. The right middle and ring- fingers are
also ulnar loops and being such are disregarded for the
reason just given. The right little finger is a tented
arch, so a lower case symbol "t" is placed after the in¬
dex finger symbol in the numerator of the formula en-
Rt
larging it to -^y-. Note that no space is left in the
formula for the middle and ring finger patterns, "t"
appearing to be from the middle finger, although it
actually is not. Continuing to the left hand, we find
a tented arch in the left thumb. As it appears before
the index it is shown by a small letter, further enlarg-
Rt
ing the sub-classification formula to — . The left
middle finger contains a radial loop, the left ring finger
an arch and the left little finger a tented arch, so all
must be represented in the formula. Using a lower¬
case symbol for each, after the left index symbol in the
order in which they appear, the complete sub-classi¬
fication formula ^ results.
tUrat
When two or three arches, tented arches or radial
loops follow consecutively after the indices of a set of
6 THE SCIENCE OF FINGER PRINTS
prints having a lettered sub-classification, they are
written as "2r," "3t," "2a," etc., with the number of
identical patterns before the symbol. For instance
\ / T T /
a set having a symbolized fraction of
X / A R R
would have for the correct sub-classification
Ua2r
formula. The figure "2" in the numerator of this sub-
classification indicates that two tented arch patterns
appear consecutively after the index. The figure "2"
in the denominator of this sub-classification likewise
indicates two successive radial loops after the left in¬
dex finger.
If a whorl or composite appears before or after the
indices it is not considered, being treated as an ulnar
loop. For instance, a set having a symbol fraction
^ ^ ^would have a sub-classification for-
TL T Ac / LP
mula of X.
T
When an ulnar loop, whorl or composite appears in
the middle finger with two arches, tented arches or
radial loops appearing, one each, in the middle and
little fingers, they are shown in the formula as ap¬
pearing consecutively, being exhibited as "2a," "2t,"
or "2r," whichever the case is. Take for example a
symbol fraction ~^ ^ ^ ^ . The index finger
/ X I W I
would be represented as in the formula. The ulnar
R
loops of the right ring finger being discarded, the ra¬
dial loops of the middle and little fingers separated by
the ulnar of the ring, would expand the formula to
LESSON SEVEN 7
U2r
——, and the tented arches of the left middle and little
R
fingers separated by the whorl of the ring finger
U2r
would complete the formula making it read———
R2t •
Remember that a composite appearing in the middle
finger would be treated the same as the whorl in this
case.
The sub-classification, when placed in the formula,
should be written right after, or following the primary
classification. The fractional division line should ex-
1 ^ Ar
tend through both. Example _ 1 ¡
l/rT2a
As was mentioned in paragraph four of page
three, this lesson, there are four loop sub-classifica¬
tions which, for convenience, we have included
under the heading of the "lettered sub-classifica¬
tion." These four loop sub-classifications result
when both index fingers are radial or ulnar loops,
or when one index finger is a radial loop and
the other index an ulnar loop, and when no arches,
tented arches or radial loops precede or follow the in¬
dex finger patterns. These four loop sub-classifica-
R U R U
tions are ' pT' pj > pj' When both index fingers are
radial loops and no arches, tented arches or radial
loops precede or follow the index fingers, the first
one or will result. For example, a set of prints
\ / \ yy CP
having —y-g—pp for a symbol fraction
R
would have the -=r- loop sub-classification. When
K
the indices, as in a set having
8 THE SCIENCE OF FINGER PRINTS
the left index finger is a radial loop and the right index
T T
an ulnar loop, the ^5— loop sub-classification will re-
K
\ \ \ CV \
suit as for a set having -j-p————- ^ for a sym¬
bol fraction. When the left index finger is an ulnar
loop and the right index finger a radial loop, no arches,
tented arches, or radial loops preceding or following
W / \ \ \
LP y CP / /
R
for a symbol fraction the loop sub-classification pj—
will result. When both index fingers are ulnar loops,
the other conditions being the same as before, as in
CP v \ X X
a set having a svmbol fraction —7 7—7 7—7-
1 y y Ac y y
_U
LT
sets of finger prints having one of these four loop sub-
classifications will, in addition, have a secondary or
second sub-classification as you will learn in the next
lesson.
the last loop sub-classification or --will result. All
Examination Questions for Lesson Seven.
Work out the sub-classifications for the following
ten sets of prints. The names of the fingers and the
types of patterns in each, are written out in the ques¬
tions. From this, construct your symbol fraction
first, and from that work out the sub-classification
formula.
(1) Right thumb-ulnar loop, right index-ulnar
loop, right middle-radial loop, right ring-arch, right
little-ulnar loop, left thumb-radial loop, left index-
LESSON SEVEN 9
tented arch, left middle-ulnar loop, left ring, ulnar loop,
left little finger-ulnar loop.
(2) Where all ten fingers are ulnar loops.
(3) Right thumb-arch, right index-radial loop,
right middle-tented arch, right ring-ulnar loop, right
little-tented arch, left thumb-ulnar loop, left index-
arch, left middle-arch, left ring-whorl, left little finger-
arch.
(4) Right thumb-ulnar loop, right index-arch,
right middle-radial loop, right ring-radial loop, right
little-radial loop, left thumb-arch, left index-ulnar
loop, left middle-whorl, left ring-ulnar loop, left little
finger-accidental.
(5) Right thumb-radial loop, right index-ulnar
loop, right middle-radial loop, right ring-radial loop,
right little-radial loop, left thumb-radial loop left in-
•dex-ulnar loop, left middle-radial loop, left ring-radial
loop, left little finger-radial loop.
(6) Right thumb-ulnar loop, right index-ulnar
loop, right middle-arch, right ring-arch, right little-
arch, left thumb-radial loop, left index-arch, left mid¬
dle-ulnar loop, left ring-ulnar loop, left little finger-
ulnar loop.
(7) Right thumb-arch, right index-ulnar loop,
right middle-radial loop, right ring-lateral pocket loop,
right little-radial loop, left thumb-ulnar loop, left in¬
dex-ulnar loop, left middle-tented arch, left ring-acci¬
dental, left little finger-tented arch.
(8) Right thumb-ulnar loop, right index-ulnar
10 THE SCIENCE OF* FINGER PRINTS
loop, right middle-central pocket loop, right ring-ulnar
loop, right little-ulnar loop, left thumb-whorl, left in-
dex-ulnar loop, left middle-ulnar loop, left ring-acci¬
dental, left little finger-ulnar loop.
(9) Right thumb-twinned loop, right index-ulnar
loop, right middle-accidental, right ring-radial loop,
right little-arch, left thumb-central pocket loop, left
index-tented arch, left middle-radial loop, left ring-
radial loop, left little finger-lateral pocket loop.
(10) Right thumb-arch, right index-whorl, right
middle-ulnar loop, right ring-ulnar loop, right little-
ulnar loop, left thumb-tented arch, left index-ulnar
loop, left middle-arch, left ring-arch, left little finger-
arch.
NAME i I P. P-FORMULA
r. p. No . '—LEDGER No I REP
RIGHT HAND
1. BIGHT THOMS
2. R FORE FINGER
J. R. MIDDLE FINGER
4. R. RING FINGER
4. R. LITTLE FINGER
Üt
(V'
¿¡¡u
Si
mssss?
'»¿¿GUT
LEFT HAND
l LEFT THUMB
7. L. FORE FINGER
8. L. MIOOLE FINGER
». U RING FINGER
10. L. LITTLE FINGER
jMJ
m
Q
; m
M-
9m
Question 11.
Work out the primary and sub-classification for
the sets of prints illustrated in questions eleven and
twelve. Exhibit same on your examination paper in
the regular formula form.
Your answers to the first ten questions count for
LESSON SEVEN
11
Question 12.
5 per cent each, and answers to questions eleven and
twelve for 25 per cent each.
Study Every Day
We know you have found everything that has
gone before very interesting or you would not have
continued your studies with such profound interest
to this point. Now that you have made such splendid
progress the remainder of the lessons will not seem
half so hard to assimilate as those that have gone be¬
fore. Once the fundamental principles and basic ideas
of .any subject are understood, as you now under¬
stand those of the finger print science, it is pure pleas¬
ure and pastime to learn the fine steps that will round
out your finger print education to the point of mak¬
ing you an expert.
Possibly there are times in the evenings when
your thoughts wander to amusements of various
kinds—times when you feel entitled to rest and re¬
laxation. On these occasions you are apt to let your
12 THE SCIENCE OF FINGER PRINTS
finger print studies slip. This is one thing you should
guard against. Do not permit a single day to pass,
without spending some time on these lessons. B}'
studying every day you maintain that strain of en¬
thusiasm and interest so vital to success in any line of
endeavor. You keep your mind on the alert, eager for
the next lesson. And best of all, you move steadily
forward to your diploma. Remember that you will
learn far more by studying a half hour each day than
by spending six hours all at one time the end of the
week. The mind can absorb just so much information
at one time. "Cramming" only makes hazy the whole
of the subject.
In the next lesson we take up the whorl sub-classi¬
fication and the secondary classification. The whorl
sub-classification corresponds in purpose to the let¬
tered sub-classification you learned in this lesson.
The only difference, as implied by the name, is that it
has to do with whorls instead of first group patterns.
The secondary classification is used as a further sub¬
division for finger print records having loop sub-
classifications. You will find lesson eight even easier
to learn than lesson seven because you have already
learned the principles which apply throughout the en¬
tire system of classification. But you must keep plug-
ging to attain that measure of success you have had
in mind ever since enrolling with the Dunlap School
of Finger Prints. By constantly keeping fresh in
your thoughts the future the finger print profession
holds in store, you have an incentive to persevere in
the study of the lessons—you should be imbued with a
"bull-dog" determination'to'complete the course with¬
out wasting a moment's precious time.
THE SCIENCE
FINGER PRINTS
Lesson Eight
□
Dunlap School of Finger Prints
1039 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Eight
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U- S. A.
Copyright 1920
by the
Dunlap School of Finger Prints
LESSON EIGHT
The Whorl Sub-Classification
We learned in the last lesson that sets of prints
containing arches, tented arches, radial and ulnar loops
in both index fingers, had a lettered sub-classification.
There must also be some method of breaking up pri¬
mary accumulations of sets having whorls and com¬
posites in the indexes. This method is called the
whorl sub-classification.
Whenever a whorl or composite or a combination of
a whorl and composite shows in the indexes, that set
will have a whorl sub-classification. If there is a
whorl in one index with any other type of pattern in
the other, a whorl sub-classification will result.
Ridge Tracing.
Whorls and composites are subdivided into three
groups by ridg'e tracing. The ridges are traced from
the left delta toward the right delta, and the whorl or
composite is classified as Inner, Meeting or Outer, de¬
pending upon how the ridge traced passes the right
delta.
If the left delta is formed by a bifurcating ridge,
the lower fork or ridge is traced across the pattern
toward the right delta. When the left delta is formed
in consequence of two diverging ridges, the lower type
line is traced toward the right delta. Therefore, be¬
fore starting to trace ridges in whorls and composites,
determine the location of the two deltas. Trace the
iower branch if a bifurcation, or the lower type line in
the case of a divergence of two ridges. The ridge may
end abruptly before reaching the right delta. In that
case drop to the ridge directly below and continue trac-
4 THE SCIENCE OF FINGER PRINTS
ing to the right. If this ridge should again end
abruptly, drop to the next one, etc., until the traced
ridg'e meets the right delta or reaches a point directly
above or below it. If a ridge which is being traced bi¬
furcates, trace the lower branch of the bifurcation. In
some cases ridges will both bifurcate and end abruptly
in their course. In that case trace the lower branch
of the ridge which bifurcates, and if this ridge ends
abruptly drop to the next one below. When tracing
ridges, be very careful to select the right delta and
trace the exact ridge, as an error of one ridge above or
below will in many cases cause the classification to be
wrong.
If the ridge traced exactly meets the right delta or
passes above or below it, that is, inside or outside of it,
with not more than two ridges intervening between
the ridge traced and the right delta, the whorl or com¬
posite is termed "meeting," designated in the classi¬
fication formula by the capital letter "M." When the
ridge traced passes above, or inside of the right delta
with three or more ridges between it and the delta, the
pattern is classified as an inner whorl and assigned the
formula symbol "I."
On the other hand, if the ridge traced passes below
or outside of the right delta with three or more ridges
intervening, the pattern is classified as an outer whorl
and given the symbol "O" in the formula.
This subject of ridge tracing is a very important
one, and the student should practice diligently on as
many patterns as he can. In the science of fing'er print
identification, the maxim "practice makes perfect" is
very true. Therefore, never miss a chance to put any
LESSON EIGHT 6
part of your finger print knowledge into practice.
You will never regret any time so spent.
In Figure 1, A is a regular whorl, the ridge tracing-
is sketched below the pattern, showing it to be outer.
B, C, D, E, are also whorls and composites in which
the ridge tracing is exhibited in like manner. Study
each of these examples carefully and be sure your re¬
sult agrees with that of the figures shown before leav¬
ing them. Ridges are traced in composites by exactly
the same method.
Ridge Counting.
It is also necessary to further subdivide radial and
ulnar loops. This is done by counting the number of
ridges between the core and delta, a certain number
setting the limit of inner and outer.
Ridges are counted in loops to divide them into
inner and outer, in certain instances when they appear
in the index and middle fingers. A loop in the index
finger is inner when one to nine ridges, inclusive, ap¬
pear between the core and delta. Ten or more ridges
intervening between the two termini make the loop
an outer. Remember that these limits are for the in¬
dex fingers only. In the middle finger the limit is
raised one ridge. In other words an ulnar or radial
loop in the middle finger, if one to ten ridges inclusive
appear between the inner and outer termini is inner.
Eleven or more ridges thus intervening place the loop
in the outer class. Remember that the delta and core
ridges are excluded from the count. The symbols I and
O are used to designate such inner and outer loops in
the classification formula.
When differentiating radial and ulnar loops as inner
X
Figure 1.
The arrow-heads on the
ridges of the sketches be¬
low each pattern, indicate
the ridge which is traced.
Ridge tracing of print "A"
shows it to be Outer. Print
"B" is Meeting. Print "C"
is Inner. Print "D" is In¬
ner. Print "E" is Outer.
Study the ridge tracing
of each pattern very care¬
fully.
THE SCIENCE OF FINGER PRINTS
LE.SSOX EIGHT
Print A—18 ridges be¬
tween Core and Delta.
Print A is Outer in both
index and middle fingers.
Print IΗId ridges be¬
tween Core and Delta.
Print II is Outer in the
index tinker and Inner in
the middle finger.
Print C—14 ridges be¬
tween Core and Delta.
Print C is Outer in both
index and middle fingers.
Print D—(> ridges be¬
tween Core and Delta.
Print D is Inner in both
index and middle fingers.
Print E—15 ridges be¬
tween Core and Delta.
Print E is Outer in both
index and middle fingers.
Figure 2.
8 THE SCIENCE OF FINGER PRINTS
find outer, be extremely cautious in selecting the pro¬
per core and delta. Be absolutely certain that you
have picked out exactly the right ridge for each ter¬
minus. It will be well for you to go back to Lesson
Three and review the text relating to the core and
delta.
Figure 2 shows several loops with a line drawn be¬
tween the core and delta; the ridge count for each is
given below the figure, in the right hand corner. Go
over each pattern carefully and verify the result given.
The Whorl Sub-Classification.
Just as sets of prints containing loops in the in¬
dexes have a sub-classification, so also do sets of prints
in which whorls appear.
If a whorl or composite appears in the indexes of
both hands or a whorl in one index with a composite in
the other, and the middle fingers are not whorls or
composites, that set will be subdivided by ridge tracing
of the index finger prints. Trace the ridges of both
patterns and thus determine whether they are inner,
meeting or outer whorls. The result will be shown in
the formula as one of the following nine possible com¬
binations :
iiMi Ql :_i _LMI 9.
I I I M M M O O O '
Take for instance a set of prints having
(I)
A W \ \ \
/ CP / / /
(°)
ior the symbol fraction. In this set the right index is
a whorl and the left index a composite of the central
pocket loop type. The other fingers are all of the first
LESSON EIGHT 9
group type. This set therefore will have a whorl sub-
classification resulting from ridg'e tracing- in the whorl
of the right index, and the central pocket loop of the
left index. The result shows the right one to be inner
and the left one outer. Using the symbols I and O,
the right hand for the numerator and the left for the
denominator, we get the formula •
Sometimes the index and middle fingers of both
hands will all be whorls or composites, or a combina¬
tion of whorls and composites. If such is the case the
ridges are traced in all four. This gives eighty-one
combinations. Take for example a set reading
(I) (M)
A CP W \ \
/ W TL / /'
(M) (O)
I lere the index and middle fingers are all of the second
group. Ridges tracing in all four fingers shows the
central pocket loop of the rig'ht index to be inner, and
the whorl of the right middle to be meeting, the whorl
of the left index, to be meeting, and the twinned loop
of the left middle to be outer. Substituting the sym¬
bols the formula reads ^ •
M O
If a loop should appear in one index with a whorl
or composite in the other, and the middle fingers are
arches or tented arches, the ridges are counted in the
loop to determine whether it is inner or outer, and the
ridges traced in the whorl. The symbols resulting
from such ridge counting and tracing are expressed as
the sub-classification. Take for example the set
10 THE SCIENCE OF FINGER PRINTS
(I)
\ \ A \ \
/ W T A / '
(M)
Here the loop of the right index has less than ten
ridges between the core and delta, so it is inner. The
whorl of the left index is meeting. The symbol I rep¬
resenting the inner loop and the symbol M for the
meeting whorl are written, the right above the left, as
~, to form the sub-classification. Bear in mind the
M
rule that if only one of the indexes contains a whorl or
a composite, that set will have a whorl sub-classifica¬
tion.
In the whorl sub-classification if the index and mid¬
dle fingers of either hand are of different types of pat¬
terns, only the index is considered. If both the index
and middle fingers are of the same type, either loops or
whorls, composites being included under whorls, both
must be considered.
Take for an example a set reading
(I) (O)
A \ W \ \
/ W CP / /
(M) (O)
Here the right index and middle fingers are of differ¬
ent types, the index being a loop and the middle finger
a whorl. Applying the above rule, only the index must
be considered. The left index, and middle fingers are
both of the same type, one being- a whorl and the other
a composite, whorls and composites being considered
of the same type, so both are used. The sub-classifi¬
cation for this set, therefore, is í—»
LESSON EIGHT 11
An arch or tented arch will sometimes appear in
one index finger with a whorl or composite in the
other. If this should occur, describe the arch or tented
arch by its symbol A or T and the result of ridge trac¬
ing in the whorl. Example ————————— •
1 / W / / /
(M)
Here the right index is an arch and the left in-
A
dex a meeting whorl. The sub-classification is —
M
There are three possible combinations each, that is
three with the arch and three with the tented arch;
\ \ A T T T
These six combinations are dou-
I M O I M O
bled by inverting the numerator and denominator.
When one index is an arch or tented arch, and the
other index and middle fingers both whorls and com¬
posites, the arch and both second group patterns are
\ T \ \ \
dealt with. Example . Elere the
/ \v CP / /
w (?)
right index is a tented arch while the left index is an
inner whorl, and the left middle finger an outer cen¬
tral pocket loop. The sub-classification for this set is
T
j-Q-. The arch and tented arch is considered in the
whorl sub-classification only when in the index fingers.
If an arch should appear in the index and middle fin¬
gers, both of one hand, and a whorl in the other, only
the index finger arch would he given consideration.
\ A A \ \ A
For example in the set WOL1^
.(°).
correct as the Sub-classification for the set. Never
A A
O
12 THE SCIENCE OF FINGER PRINTS
Second Sub-Classification.
Certain sets of prints composed of loops and
whorls, composites included, will have a "secondary"
or second sub-classification. This follows the first
sub-classification in the formula.
When the index fingers are radial or ulnar loops
or one is radial and the other ulnar, the remaining fin¬
gers all being ulnar loops, a secondary classification
will result. The sub-classification is shown after the
U R U R
primary as one of the following four : --- —- —' —p
U R R U
No other sub-classifications are followed by a secon¬
dary.
The secondary classification results from counting
the ridges in the index fingers in some cases, and in
other cases from counting the ridges in both the index
and middle fingers. In a set reading ^———————
\ve see that all the patterns are ulnar loops. Being of
the first group this set will have a primary classifica¬
tion of The sub-classification is yy-. The secon¬
dary is formed by counting" the ridges of the index and
middle fingers of both hands. The result will be one
of the following" sixteen combinations :
I I, I O, O I, O O, 11, 10, O I, O O, II, I o, o I,
II I I II II 10 10 10 10 OI OI OI
0 0, I I, 10, O I, o o
01 OOOOOOOO'
In a set reading ^^^^^, where both in-
R,
dex fingers are radial loops, the sub-classification is
R
and the secondary results from counting the ridges in
LESSON" EIGHT 13
the index and middle fingers of both hands, as in the
ease of all ulnar loops. The same holds true if one in¬
dex is radial, the other ulnar, and both middle fingers
ulnar, with all the remaining patterns ulnar loops or
whorls and composites.
Here is an important rule to remember. If an arch,
tented arch or radial loop should precede or follow ul¬
nar or radial loops in the indexes, the secondary classi¬
fication is eliminated. That is, a set in which such pat¬
terns appeared before or after ulnar or radial loops in
the indexes would have no second sub-classification
íesulting from ridge counting. Take for example the
set —————————• Here the primary classification is^-
/ / / / / 1 * 1
The sub-classification is -. The right middle finger
is a radial loop, so in applying the rule that when an
arch, tented arch, or radial loop, precedes or follows
the index finger, the second sub-classification is elim¬
inated, and the lettered sub-classification is substi-
U3r
tuted. \\ e get the lettered sub-classification of
for this set.
As in the whorl sub-classification, when the index
and middle fingers are of different types, that is, when
one is a loop and the other a whorl, only the indexes
are considered. For example
(I) (O)
\ \ \ \ \
"7 \ W / 7
(O) (M)
Here the indexes are both loops, and as no arches,
tented arches or radial loops precede or follow them,
chis set will have a secondary classification. The sub-
14 THE SCIENCE OF FINGER PRINTS
classification is The right index and right middle
fingers are of the same type, so both are considered.
The left index and left middle fingers are of different
types, so only the index is considered. The secondary
classification for this set then, is .
\ CPA X.
Take for example a set reading
/ W / /'
here the sub-classification is As the index and
middle fingers of both hands are of different types
than the indexes, the former only are considered. This
set would therefore have one of the following four sec¬
ondary or second sub-classifications : —. —. —, —.
1IOO
Bear in mind that ulnar and radial loops are con¬
sidered to be of the same type when the latter appear
in the indexes and the former in the middle fingers.
In actual work the finger print expert will handle a
large number of records, requiring secondary classifi¬
cation. The largest percentage of patterns are ulnar
loops, with whorls following in predominance. The
combinations following these two types are such that
they will require either a whorl sub-classification or a
second sub-classification, so spend quite a bit of time
on this lesson and learn it thoroughly.
The final classification provides the final means of
breaking up accumulations. This is formed by ex¬
hibiting the ridge count of the loop in the right little
finger when such occurs. In any set of prints where
the right little finger is an ulnar or radial loop, count
the ridges between the two termini, excluding the last
LESSON EIGHT 15
mentioned points from the count, and place the result¬
ing number in the numerator of the formula follow¬
ing the sub- or second sub-classification, whichever the
case may be. Take for example a set having a formula
^If there were twelve ridg'es intervening
between the core and delta of the loop in the right lit¬
tle finger of this set, the complete classification form¬
ula, including the final, would read ^ ——
J 8 R O
Sometimes the right little finger will contain a
whorl, while the left little finger is a loop. In that case
count the ridges of the left little finger and write the
number in the denominator of the formula as
. 7 U 10
22 R O 12'
In bureaus where a very large number of records
are on file, half a million for instance, the ridges are
counted in both the right and left little fingers when
same are loops, exhibiting the right little fing-er count
in the numerator and the left little finger count in the
denominator, as , ' P p°—or whatever the
18 R O 16
count happened to be.
Examination Questions on Lesson Eight.
(1) What is the whorl sub-classification com¬
posed of?
(2) What is the purpose of the sub-classifica¬
tion ?
(3) How do you tell whether a whorl is Inner,
Meeting or Outer?
(4) How many ridges appear between the delta
and core of an inner loop in the index finger? In the
J6 THE SCIENCE OF FINGER PRINTS
middle finger ? Of an outer loop in the index finger ?
In the middle finger ?
(5) Under what conditions does a set of prints
have a secondary classification?
(6) What are the symbols used for whorls in the
sub-classification? For loops in the second sub-classi¬
fication?
(7) What four secondary classifications are pos-
_ No
F. P. FORMULA.
REF
. RIGHT THUMB
2. R. FORE FINGER
î. R. MIDDLE F
1. RING FINGER
5. R. LITTLE FINGER
fllMMI
S. LEFT THUMB
LEFT HAND
.. RING FINGER
.
. L. tITTLE FINGER
NAME
F. P. No.
Figure 1.
„LEDGER No
No
F. P. FORMULA
REF
. RIGHT THUM8
RIGHT HAND
2. R. FORE FINGER
3. R. MIDDLE FlNQER
S. R. LITTLE FINGER
LEFT HAND
7. L. FORE FINGER
a. L. MIDDLE FINGER | I. L. RING FINCER
Figure 2.
LESSON EIGHT 17
sible, resulting from ridge counting of loops in both
indexes?
(8) What sixteen secondary classifications are
possible resulting from ridge counting of loops in both
index and middle fingers?
(9) Are arches, tented arches or radial loops con¬
sidered when appearing before or after whorls in the
indexes ?
(10) What nine combinations are possible when
a whorl appears in both indexes, with arches in both
middle fingers? - '
(11) Work out the sub-classifications for the
two sets of prints illustrated in figures 1 and 2.
(12) Woi;k out the lettered sub-classificatibns for
the two sets of prints illustrated in figures 3 and 4.
Your answer to each of the first ten questions will
count for five per cent, and twenty-five per cent for
each of questions 11 and 12.
r. r. foamula_
Rir
right hand
1. RIGHT THUMB
Í A. F 0*1 Fl AGFA
X A. MIOOU Fl AGFA
«. R. RING FINGER
X A. UnU FINGEA
■ Éiiiyp
III
©
. i«*?*.
■UNIA»!-
lfcft hand
Figure 3.
THE SCIENCE OF FINGER PRINTS
V*
Figure 4.
THE SCIENCE
of
FINGER PRINTS
Lesson Nine
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Nine
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 192 2
by the
Dunlap School of Finger Prints
LESSON NINE
Combinations, Amputations, and the Classification of
Indistinct Finger Prints—Order of Filing
It is a regrettable thing, but still a fact, that many-
finger print records contain prints very poorly made ;
in many instances so blurred as to be undecipherable.
This greatly hampers correct classification. It is not
fair to say that it is the operator's fault in every case,
however, as a subject may have fingers in such bad
condition that it is impossible to obtain good, clear
impressions from them. In all instances where one
or more such bad impressions occur in a set, more
than one classification formula will have to be worked
out, and the files searched under each until a duplicate
is found or the search exhausted.
If a print is not too badly blurred or too indistinct,
the type of pattern can usually be determined, thus
giving the operator comparative assurance as to the
correct primary classification. Where a print is too
badly blurred to determine whether it is of the first or
second group, that is, a non-numerical or a numerical
type, it must be classified, first as one, then as the
other, the file being searched under each heading.
Order of Filing
In order that the student may grasp more,easily
the method of computing combination formulas,
especially where more than one digit is missing,.it be¬
comes necessary to have a knowledge of the order in
which finger print records are filed by, their classifi¬
cation. . .
4 THE SCIENCE OF FINGER PRINTS
The finger print formula is divided into four parts,
the (1) primary, (2) sub-classification, (3) secondary
classification, and (4) the final classification. The
primary classification is first considered in filing a
record. Records are arranged in numerical sequence,
first according to the size of the number making up
the denominator of the primary fraction and secondly
according to the numerator number. Thus a primary
classification with a denominator __ would precede in
filing order a primary classification with a denominator
A denominator _ , would precede _ and _ would
2 2 3 3
precede _ etc. As was just mentioned, the second
4
arrangement is according to the numerator number.
Thus of two primary classifications JL* the J._
1 1 1
would precede in filing order the 2_ as the numerator
number 1, is smaller than the numerator number 2, the
denominator being the same. Likewise 31 would
18
precede 32 or 1 would precede iL , etc.
18 17 17
Now where there are a large number of finger
print records to be filed there will be many bearing the
same primary classification. It is here that the sub-
classification is taken into consideration. As you
learned in lessons seven and eight, there are two kinds
of sub-classifications, depending upon the patterns in
the index fingers. There is the loop sub-classification
and the whorl sub-classification. The left index finger
constitutes the first order of filing in both the loop
and whorl sub-classifications. In the loop sub-classi¬
fication the order is A, T, R, and U; in the whorl sub-
LESSON NINE 5
classification the order is I, M, and O. When the
records have been arranged in the A, T, R, U
order,, according to the denominator in loop sub-
classifications, they are next arranged according
to the pattern of the left thumb, then left middle
finger, then left ring finger and then left little
finger, always in the same A, T, R, and U order.
The right index forms the next order, also by A, T,
R, and U, then according to right thumb, right mid¬
dle, right ring, and right little finger again in the
A, T, R, and U order. For instance, a loop sub-classi¬
fication reading _A would precede in order of filing a
A
loop sub-classification reading T ;-k m 1 would
Ä A
precede R and F would precede U_, etc. In the let-
A R R
tercd group, A would precede _A and _A would
aA Äa Au
precede a A , etc..
A
Between the all-lettered and all-whorl sub-classi¬
fication comes the combined lettered and whorl sub-
classification. In other words the following sub-
classifications jy' etc., would follow
in order the - or lettered sub-classifications just
explained.
When an arch or tented arch appears in one index
in combination with a whorl or composite in the other
index, the order of filing is as follows: —
. . . A . A A
(when the arch appears in the left index and the
whorl or composite in the right index). When a
tented arch appears in combination with a whorl or
6
THE SCIENCE OF FINGER PRINTS
composite in the same fingers the order is — Mi M
T T T
This order is followed by ~ j' M' T,
(when the whorl or composite is in the left index fin¬
ger and the arch or tented arch in the right index).
When a radial or ulnar loop appears in the left
index with a whorl or composite in the right index
(see lesson eight for classifying loops in whorl sub-
classifications) the order is ¿ Mi M M M» M.
This is followed by the combination of two loops in
the left index and middle finger with a whorl or com¬
posite in the right index as
I, M, 0, J, M, O, l M, O,
II II II 10 10 10 01 01 OI
J». _M, S>-
00 00 00
This is followed by the combination of a loop in the
left index and middle finger and whorls or composites
in the right index and middle fingers. This would re¬
sult in the following combinations and order of filing:
II, IM, 10, MI, MM, MO, Ol, OM, 00,
II ' II II II II II II II II
II, IM, 10, MI, MM, MO, OI, OM, 00,
TO 10 10 10 10 10 10 10 10
II. IM, 10, MI, MM, MO, 01, OM, 00,
Öl Ol ÖI OI 01 01 01 01 OI
TL IM, 10. MI, MM, MO, OT. OM, OO.
00 OO 00 OO 00 00 00 00 OO
In all these combinations of non-numerical types
in the left hand and numerical types in the right hand,
the sub-classifications would be the same if the non-
numerical types appeared in the numerator and the
LESSON NINE
numerical types in the denominator, but the order of
tiling would be :
II,
10,
Ol,
00,
11
II
II
II
II,
10,
Ol,
00,
IM
IM
IM
IM
II,
10,
Ol,
00,
10
ÏO
10
10
II,
10,
Ol,
00,
MI
MI
MI
MI
II,
10,
Ol,
00,
MM
MM
MM
MM
II,
10,
Ol,
OO,
MO
MO
MO
MO
II,
10,
Ol,
00,
Öl
Ol
Ol
Ol
II,
10,
Ol,
00,
OM
OM
ÖM
OM
II,
IO,
Ol,
00,
OO
00
00
OO
In the whorl sub-classification, (remember that
composites are classified the same as whorls) the left
index again forms the first order of filing in the order
of T, M, and O. The second order is according to the
left middle finger likewise by I, M, O. The right
index and right ring fingers form the third and fourth
order respectively, also by I, M, O. Thus I would
I
precede J and I_ would precede _I , and M would
M M O I
precede O . Likewise, ff would nrecede IT and
I IT IM
TM would nrecede TO . etc. In other words, when
TO TO
onlv the two index fingers are considered, the order
. ' „ T. M. O, I. M.O, I. M, O. ,
is as follows: j T j m M M O O O And
8
THE SCIENCE OF FINGER PRINTS
when both index and middle fingers are considered th(
order is:
11,
IM,
IO,
MI,
MM,
MÖ,
01,
OM, 00,
11
II
II
II
11
11
11
"II II
11,
IM,
10,
MI,
MM,
MO,
-01,
OM, 00,
IM
IM
IM
IM
IM
IM
IM
IM" IM"
II,
IM,
10,
MI,
MM,
MO,
01,
OM, 00,
10
10
10
10
"10
10
10
10 10 "
II,
IM,
JO,
Ml, MM,
MO,
OI,
OM, 00,
Ml
MI
Ml
Ml
Ml
MI
Ml
Ml "MI
II,
IM,
10,
MI,
MM,
MO,
OI,
OM, OO,
MM
MM
MM
MM
MM
MM
MM
MM MM"
II,
IM,
10,
MI, MM, MO,
01,
OM, 00,
MO
MO
MO
MO
MO
"MO
MO
MO MO"
II,
IM,
10,
MI,
MM,
MO.
OI,
OM, 00,
OI
Ol
Ol
OI
01
01
01
. 01 01
II,
IM,
10,
MI,
MM,
MO,
01,
OM, 00,
OM
OM
OM
OM
OM
OM
OM
OM OM
II,
IM,
10,
MI,
MM,
MO,
01,
OM, 00,
OÖ
00
00
00
00
00
00
00 00
The loop
sub-classification of the lettered divisior
is followed in order of filing by the secondary classi¬
fication, which is the result of ridge counting in loof
patterns of the index fingers also the index and mid¬
dle fingers. (See lesson eight.)
After each of the four loop sub-classifications
r' t7 ü' secon^ary glides are arranged ir
the order of j' y' yj and |y when only the inde^
fingers are loops. The second arrangement is wher
the index and middle fingers of the left hand are loops
and only the index finger of the right hand, the righl
middle finger pattern being of some other type
LESSON NINE
9
Then the order is n' n' QI' — Q¿
R TJ R TT
after each of the sub-classifications - ' ' - ' — '
R R U U
Following these would be records where the index and
middle fingers of the right hand were both loops and
only the index of the left hand a loop. The order
,, be II, 1Ü, Ol, GO, II, 10, 01, 00.
W0U I T I "I o o o o
When the index and middle fingers of both hands
are ulnar or radial loops, the following sixteen sub-
classifications result and are filed in this order, after
each of the four sub-classifications —* '
R R U U
II,
10,
o
o
i—r
c
ÍI
II
II II
II,
IO,
01, oo,
ÏO
IO
10 10
II,
10,
01, 00,
01
01
01 OI
II,
IO,
01, 00,
00
00
00 00
The last order of filing is by the final classification
or ridge count of the right little finger loop. If the
right little finger pattern is not an ulnar or radial loop,
of course that record will not have a final classifica¬
tion. The order of filing in the final classification is
simply numerical according to the number represent¬
ing the ridge count of the loop. Thus a final classifica¬
tion of 1, would precede 2, and 2 would precede 3, etc.
Remember now that the primary classification
forms the first order of filing in the orders given. All
sets having the same primary classifications are
10 THÈ SCIENCE ÖF FINGER PRINTS
further arranged according to the sub-classifications,
which may be of either the lettered or whorl type.
All sets having the same primary and sub-classifica¬
tions are further arranged according to the final classi¬
fication. All sets having the same primary classifica¬
tions with one of the following sub-classifications
p-' -p-' pj.' -pA are further arranged according to the
secondary classification and last according to the final
classification.
Take for instance in the set of prints illustrated in
figure 1. In this set the right index print is so blurred
that one is not certain in classifying it as a loop be¬
cause this impression could just as well be a central
pocket loop and thereby come under the numerical
group. It is supposed that the man from whom
these prints were taken has a previous record on file.
But as to how these prints had been classified at that
time is uncertain. The first thing therefore, is to class-
FIGURE 1.
LESSON NINE 11
ify it as a whorl. This gives a primary classification of
—. Considering the right index print to be a whorl,
21
a whorl sub-classification will result. Here again a
difficulty confronts the classifier. Is the whorl inner,
meeting or outer? It is too blurred to trace any
ridges. It must be classified and searched under each
heading. We will consider it first as inner. Count¬
ing the ridges of the loop in the left index finger the
print is shown to be outer. As the middle fingers are
of different types of patterns than the index in both
hands, they are not to be considered. Counting the
ridges of the loop of the left little finger for the final
classification, gives 15 as the result. The complete for¬
mula would then be ^ ^ The right index fin-
21 O 15
ger must also be considered as both meeting and
outer, providing search has failed to locate a dupli¬
cate under the first formula. Thus ——M and
21 O 15
——— would also have to be considered. Now there
21 O 15
is a possibility of the right index finger being of the
first group. This changes the primary classification to
Considering the blurred pattern as being an ulnar
loop first, this type of pattern predominating, the
complete formula —- results. As a radial loop
21 U 15
consideration the formula ——— will result.
21 U 15
Then considering it first as an arch and lastly as a
tented arch, the classifier gets the formulae 3 Aa
21 U 15
12 THE SCIENCE OF FINGER PRINTS
and 3 Ta This exhausts the search for this
21 U 15
set of prints, as the student will readily see.
In nine cases out of ten a print will not be so
badly blurred that the general type cannot be distin¬
guished. If the type, as far as non-numerical or
numerical, can be ascertained by examination, some
of the combinations will be eliminated both in the pri¬
mary and also in the sub-classification, especially
where the index finger is affected and where several
of the prints are indistinct.
Where more than one print is blurred the task of
working out the combination becomes correspond¬
ingly more difficult, especially if both index fingers
are involved. Take for instance in the set illustrated
in Fig. 1, if the left index print was in the
same condition as that of the right index, there
would be two more, or four possible primary com¬
binations, namely, the two alreadv considered, — —
21'21
1Q 3
and and ~ , considering the left index finger a
¿O cO
whorl and then a loop. Of course, many additional
combinations in the sub-classifications would result.
That is, we do not know whether the right index is
inner, meeting or outer, in the case of a whorl, or
whether the left index is inner, meeting or outer, so
each must be considered under the various combina¬
tions, also under all the "lettered" or "A," "T," "R"
and "U" combinations. •
Considering both the right and left index fingers
of the set illustrated in Figure 1, to be badly blurred,
LESSON NINE 13
that is, so the type of pattern cannot be ascertained,
let us see how an exhaustive search of the files for a
duplicate record can be made, taking it for granted
that the ridges on the two index fingers were in per¬
fect condition wh.en.the first set of impressions was
taken and filed.
First we will suppose that both index fingers were
loop patterns. This would result in the primary
3
classification -yr. Then as both index fing-ers are of
the first group type and an arch follows in the right
hand; a lettered sub-classification will result. (See
lesson seven.) Assuming that both index fingers are
ulnar loops, first, we get the complete classification
3 Ua
2^ Then pretending that they are both
3 Ra
radial loops we obtain the formula ^—j-=- ¡then
as arches we get ^ 15 > then as tented arches
3 Ta
we get -^1—y;—Then we must alternate and first
1 I I
consider the left index finger to be an ulnar loop and
3 Ra
the right index a radial, giving Tyy——jy, then the
right index as changing to an arch and finally a tented
arch with the left index still an ulnar loop, giving
21 U& 15"' ?1 TT 15" as a result. Then we change
the left index to a radial loop and use the same combi¬
nations for the right index. This gives the following
3 Ua 3 Aa 3 Ta T,
formulas: 21 R 15> 21 R 15 ' 21 R IS' Then
changing the left index finger to an arch and using
14 THE SCIENCE OF FINGER PRINTS
the same combinations for the right index we get
3 Ua 3 Ra 3 Ta t-- n i
21 A 15' 21 A 15'"20015' Fmally chang"
ing the left index to a tented arch, and using the same
combinations for the right index as before, Ave get :
3 Ua 3 Ra 3 Aa ^ i ,
21 T 15"' 21 T 15 ' 21 T 15" w
gather all these combinations together. They are :
3 Ua 3 Ra 3 Aa 3 Ta
21 U 15' 21 R 15' 21 A 15 ' 21 T 15
3
Ra
3
Aa
o
0
Ta
21
U
15'
21
U
15'
21
U
15
3
Ua
3
Aa
3
Ta
21
R
15'
21
R
15'
21
R
15
3
Ua
o
0
Ra
3
Ta
21
A
15'
21
A
15'
21
A
15
3
Ua
3
Ra
o
0
Aa
21
T
15'
21
T
15'
21
T
15
The next step is to arrange these formulas in their
proper order of filing. The primary classifications are
identical so they must be arranged according to their
lettered sub-classifications. As A, T, R, U, by left in¬
dex forms the first order of filing, gather together
those formulas showing arches in the left index.
These are
3 Aa 3 Ua 3 Ra 3 Ta
21 A 15' 21 A 15' 21 A 15' 21 A 15
The second order of filing is A, T, R, U, by right index,
so next arranging these four formulas in this order by
right index finger we get
3 Aa 3 Ta 3 Ra 3 Ua
21 A 15' 21 A 15' 21 A 15' 21 A 15"
In a like manner arranging the remainder of these for¬
mulas we get :
LESSON
NINE
3
Aa
3
Ta
3 Ra
3
Ua
21
T
15 '
21
T 15 '
21 T
15' 21
T
15
3
Aa
3
Ta
3 Ra
3
Ua
21
R
15 '
21
R 15'
21 R
15' 21
R
15
3
Aa
3
Ta
3 Ra
3
Ua
21
U
15 '
21
U 15'
21 U
15' 21
U
15"
We next change the right index to a numerical
group pattern. This gives 19 for the primary classi¬
fication, and the sub-classification will be of the whorl
kind (see lesson eight) resulting from ridge tracing
of the right index finger and ridge counting of the
left index finger. As the middle fingers of both hands
in this case are of different types than the indexes,
only the indexes are to be considered. The whorl or
composite in the right index finger is either inner,
meeting, or outer. The symbols I, INI, and O of the
right index finger are then combined with the non-
numerical group symbols A, T, R, and U. You will
recall, of course, from lesson eight, that when a whorl
appears in one index finger in combination with a loop
of the other index, ridges are counted in the loop, sep¬
arating it into inner and outer. Therefore, we get the
formula combinations:
19
I
19
M
19
0
21
A
15'
21
A
15'
21
A
15 '
19
I
19
M
19
0
21
T
15'
21
T
15'
21
T
15'
19
I
19
M
19
O
21
I
15 '
21
I
15 '
21
I
15 '
19
I
19
M
19
O
21
0
15 '
21
O
15'
21
0
15.
Now we arranged the above formulas in their
16 THE SCIENCE OF FINGER PRINTS
proper order of filing as we went along so no re¬
arrangement is necessary.
Considering the right index to be of the non-
numerical group and the left index to be of the nu¬
merical, provides our third primary classification
3
change of We now have numerical type pat¬
terns in both the left index and middle fingers so both
are to be considered in making up the formula. (See
lesson eight.) Working out the combinations for the
left hand becomes a little more complicated in this case
because we have two fingers to deal with, and three
combinations, that is, I, M, and O are possible in each
of the two fingers. If you will constantly bear in
mind the order of filing you will find the process com¬
paratively easy. In this case, the index of the left
hand forms the first order of filing and the middle
finger of the left hand the second order. This gives
the following nine combinations II, IM, 10, MI, MM,
MO, 01, OM, 00. You see, we first used the symbol
"I" three times for the index finger, combining it suc¬
cessively with the symbols I, M, and O for the middle
finger, giving the three combinations II, IM, and 10.
We then changed the index finger symbol to "M" and
combined it in the same way with the symbols I, M,
and O, for the middle fingers giving the second set of
three combinations MI, MM, and MO. Lastly we
changed the index finger symbol to "O," and again
combined it successively with the symbols I, M, and O
for the middle finger giving the last three combina¬
tions 01, OM, and 00. Combining these nine denomi¬
nators with the "A" symbol of the non-numerical pat¬
tern in the right index and the primary and final classi-
LESSON NINE 17
fications we get the following formula combinations:
3
A
3
A
3
A
23
II
15'
23
IM
15 '
23
10
15'
3
A
3
A
3
A
23
MI
15 '
23
MM
15'
23
MO
15'
3
A
3
A
3
A
23
01
15'
23
OM
15'
23
00
15 "
Combining the same sub-classification denomina¬
tors successively with the "T" symbol, in the numera¬
tor which is the second order of filing for non-numer¬
ical types, we get the second set of nine combinations:
3
T
3
T
3
T
23
3
II
T
15 '
23
3
1M
T
15'
23
3
10
T
15 '
23
3
MI
T
15 '
23
3
MM
T
15 '
23
3
MO
T
15'
23
01
15'
23
OM
15'
23
00
15 '
Now when we get to combining these denominator
combinations of the sub-classification with the radial
and ulnar loop classification of the non-numerical type
in the right index we must use the symbols I and O
representing inner and outer loops. (See lesson
eight.) This gives the following eighteen formula
combinations :
3
I
3
I
3
I
23
II
15 '
23
IM
15'
23
10
15'
3
I
3
I
3
I
23
MI
15'
23
MM
15 '
23
MO
15 '
3
I
3
I
3
I
23
01
15'
23
OM
15'
23
oo
15'
3
O
3
0
3
o
23
II
15'
23
IM
15'
23
10
15'
3
O
3
0
3
0
23
MI
15 '
23
MM
15 '
23
MO
15'
18 THE SCIENCE OF FINGER PRINTS
3 O 3 O 3 O
23 OI IS' 23 OM IS' 23 00 IS'
The last step is to consider both missing indexes
to be of the numerical type. This gives the fourth
19
primary classification combination The same
denominator combinations in the sub-classification
will result as under the last primary classification
which was -yr ; namely, II, IM, 10, MI, MM, MO, 01,
OM, and 00. These nine denominator combinations
will be combined first with the symbol "I" for the
numerator, representing the numerical type in the
right index, then with "M" and finally with "O."
This gives the following twenty-seven formula com¬
binations :
19
I
19
I
19
I
23
II
15'
23
IM
15'
23
10
15 '
19
I
19
I
19
I
23
MI
15'
23
MM
15'
23
MO
15'
19
I
19
I
19
I
23
01
15'
23
OM
15'
23
00
15'
19
M
19
M
19
M
23
II
15'
23
IM
15'
23
10
15'
19
M
19
M
19
M
23
MI
15'
23
MM
15'
23
MO
15'
19
M
19
M
19
M
23
OI
15'
23
OM
15'
23
00
15 '
19
0
19
0
19
0
23
II
15''
23
IM
15'
23
10
15 '
19
0
19
O
19
0
23
MI
15'.
23
MM
15 '
23
MO
15'
19
0
19
0
19
0
23
Ol
15'
23
OM
15'
23
oo
15 '
We have now worked out all the possible classifica¬
tion combinations providing for an exhaustive search
LESSON NINE 19
)f the files for a duplicate of this record considering
:hat the two index fingers were nice clear impressions
ind could be properly classified when the first set of
mpressions was taken and filed. In other words, the
first set is filed under any one of these ninety (90)
:lassification formulas, and so a systematic search
nust be made, starting with the lowest primary classi-
3
fication combination, which in this case would be -yy *
Under this primary division the search would proceed
iccording to the order of filing in the sub-classifica¬
tion. The search would then be shifted to the pri-
19
nary division -yy and proceed through the various
sub-classifications just 'figured. If the search had
failed so far to locate the duplicate, we would continue
3 19
in the same way with -yyancbyy.
When one or more of the other fingers preceding
or following the indices are blurred, the classification
will not be affected as much. For instance in the set
illustrated, Fig. 1, if the right ring finger pattern was
blurred or indistinct and the right index was clearly
a whorl, the primary classification would be
y~, calling the right ring a non-numerical type. If a
numerical tvpe, the primary classification would be
°7
changed to ~ ^. As this set has a whorl sub-classifi¬
cation, the ring finger pattern would not affect it.
Hint.
When indistinct prints show in a set, classify them
as far as possible as to type; this will eliminate part
of the work.
20 THE SCIENCE OF FINGER PRINTS
In the above text there have been covered the
basic principles upon which the combinations in the
classification formula are computed. Each individual
case will be different though, so in order to become
better versed in this subject it is advised that the
student make up several cases of blurred prints and
work out all the combinations in each. Do it syste¬
matically. First figure out all the possible changes in
the primary classification. Then determine how the
sub-classifications will be affected by each primary
change and work out all the sub-classification combi¬
nations possible with each such change. If the set
will have a secondary classification in consequence of
any primary or sub-classification change, work out the
combinations for it also. Then arrange your primary
classifications, each followed by its various sub-classi¬
fication combinations in the proper order of filing.
Where the little fingers cannot be properly classified,
due to indistinctness, the final classification is omitted.
Amputations
Not infrequently a subject to be finger printed
will have one or more missing fingers, due to amputa¬
tion. To locate a duplicate record of such person in
the files, two methods will have to be followed. First
consider that the fingers were missing at the time
such previous records were made. Secondly, suppose
the fingers to have been amputated since the first set
was taken. This will necessitate working out all the
formula combinations. .
Whenever a set of prints contains amputations,
such missing fingers are first classified exactly the
same as the corresponding digit on the other hand.
LESSON NINE 21
Thus if the left index finger was missing, and the
right index finger was a tented arch, the left index,
which is missing, would also be classified as a
tented arch. The original set, or first taken of a
subject, is thus classified and filed. If both corre¬
sponding digits of a set of prints were missing, they
must both be classified as meeting whorls. Therefore,
whenever you have a record of this sort and have sat¬
isfied yourself that no previous record of that person
is on file, classify it as above and file it accordingly.
Some bureaus file all sets of prints containing missing
fingers in a separate file drawer. This latter idea is
well to follow if a bureau has a very large number of
records to file and index.
The abbreviated form of the word "Amputated" or
"Amp.," must always be written at the end of the
classification formula, and also in the spaces provided
for those fingers of sets containing missing digits,
when classifying for filing.
To return to the subject of searching for dupli¬
cates of sets embodying abscissions; first consider
such removals to have been made previous to the first
record. Classify the missing digits as above, that is,
to correspond with the same finger of the other hand
and search the files accordingly. If this fails to lo¬
cate such duplicates, the other method must be em¬
ployed.
This other method is exactly the same as used for
indistinct prints. That is, the missing print is consid¬
ered to be of each type, all the combinations possible
being worked out and searched for under each consid¬
eration. This latter method is rather complex as you
22 THE SCIENCE OF FINGER PRINTS
yourself have no doubt concluded by this time, es¬
pecially when several digits are missing, so be very
certain that your search is exhaustive.
One important point in classifying such sets, is that
the abbreviated form of the word, or ''Amp.," is also
written in the space reserved for such missing finger.
Another point :—when recording prints of a person
not possessing all ten fingers, leave blank the spaces
reserved for such missing prints, recording each fin¬
ger in its proper allotted space.
Damaged Fingers
Prints taken from damaged fingers are to be classi¬
fied the same as indistinct prints or amputations if
the resulting print is so indistinct as to show no ridge
formation, When classifying the original set of im¬
pressions for filing make the notation "damaged" in
the formula followed by the number of fingers so af¬
fected, enclosing this notation in parentheses. For
example, we will suppose we had a set of prints giv¬
ing this symbol fraction ^ ~—-y—^—y-—. The
square in the right ring finger space indicates the
damaged finger of which a print could not be taken.
The formula for this set would then read:
5 Art (4 damaged)
1 Ur ~
If a damaged finger makes an impression showing
at least part of the ridge formation it should be classi¬
fied the same as a blurred or indistinct impression.
LESSON NINE 23
Examination Questions on Lesson Nine
1. How is an amputation noted in the classifica¬
tion formula of a set of prints?
2. In an original set of prints or the first taken
of the subject, where the right index finger had been
amputated, how would it be classified for filing?
3. In case the right and left thumb were both
missing, how should they be classified for filing?
4. What should be written in the space provided
for an amputated finger?
5. What will cause a greater number of possible
combinations in the classification formulae, a missing
index finger or a missing ring finger?
6. In working out combinations how many
changes are possible in the primary classification
when one finger is missing?
7. When two digits are missing?
8. How do some large bureaus file sets of prints
containing amputations?
9. What type of patterns appears most fre¬
quently?
10. What type of pattern is most seldom found?
11. Work out all the possible combinations in
both primary and sub-classification for the following
set of prints, illustrated on page 24, in which the left
index and middle finger patterns are missing. Ar¬
range your formulas in their proper filing order.
Your answers to the first ten questions will count
for five per cent each. The answer to Question 11
for fifty per cent.
QUESTION 11.
THE SCIENCE
of
E FINGER PRINTS
Lesson Ten
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Ten
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON TEN
Finger Print Photography
Records of latent finger prints are secured by mak¬
ing photographic copies of them, as you were taught
in a previous lesson. Photographs are also taken of
ink prints for making exhibits to prove identity in
court.
If it is at all possible, the finger print expert
should learn to do his own photographing. It is not
absolutely necessary that he do it, but he will be bet¬
ter satisfied if he does. In any case, he should be able
to instruct a commercial photographer as to how the
best results can be obtained, because this kind of work
will be new to most photographers. Many students
will have no knowledge of the principles of photog¬
raphy. Therefore, it will be necessary to study this
lesson carefully, so that if you do not intend to do your
own work, you will have sufficient knowledge to in¬
struct the photographer.
Apparatus
The apparatus needed is a camera, tripod, focusing
cloth, plates and plateholders.
The camera for general work should be one of the
standard makes. The Premo Cameras, numbers Nine
and Ten, manufactured by the Eastman Kodak Com¬
pany of Rochester, N. Y., are very good types of
cameras for this purpose. See Figure 1.
The camera should take a picture five inches wide
by seven inches long.
4
THE SCIENCE OF FINGER PRINTS
FIGURE 1.
The bellows of the camera should be of long ex¬
tension capacity, about nineteen or twenty inches.
It should be equipped with an anastigmat or rapid
rectilinear lens. The anastigmat lens is preferable, as
it. is corrected for astigmatism. That is, it will sharply
reproduce vertical and horizontal lines in the same
picture. The rapid rectilinear lens is also corrected
for this fault, but not to so great an extent as the anas¬
tigmat. Any deficiencies that the rectilinear lens has
LKSSON TEX 5
can be further corrected by stopping it down, that is,
using a smaller diaphragm opening, as explained later
on. The cheaper type of lens known as the meniscus
achromatic, is useless for finger print photography.
The lens of the camera should be fitted into an
automatic shutter. The shutter should operate by a
cable release or a bulb. This is to prevent any jarring
of the camera while releasing the shutter to make an
exposure for a finger print. Any jar, no matter how
slight, would spoil the picture. A shutter operating
by five hinged metal leaves and opening in the shape
of a star is best, as it permits the maximum amount of
light to reach the plate in the shortest amount of time.
The shutter should be equipped with an iris dia¬
phragm. The diaphragm is a series of metal leaves,
opening in the shape of a circle by being hinged at one
end and movable at the other. The function of the
diaphragm is to regulate the depth of focus. The size
of the circle can be increased or decreased by moving
a lever on the outside of the shutter barrel. Making"
the circle smaller increases the depth of focus of the
lens by reason of using only the center or thickest part
of it. It also sharpens the definition. When photo¬
graphing finger prints the smallest diaphragm open¬
ing should he used, to insure a sharp reproduction of
the ridges, composing the print, in the photograph.
A shutter working at an instantaneous and time
exposure will serve the purpose of the finger print
photographer, providing it possesses the above essen¬
tials.
The camera must have a ground glass focusing
screen in back. This permits of the camera being
6 THE SCIENCE OF FINGER PRINTS
sharply focused, so that each ridge will reproduce
clearly.
A plate is the best medium for the negative. Films
of large size are hard to handle. Plates are made up
in all kinds of speeds and emulsions, so you can get
just the kind to suit your purpose. When making
finger print photographs use a plate with a very slow
emulsion. Such as a process or copying plate. It
should be backed to prevent halation or glare, caused
by reflection on the emulsion from the back. This
halation is caused by very bright or high lights ap¬
pearing in the field of the view covered by the camera.
If you do not intend to do your own work and ex¬
pect to use an outside photographer,' see that all the
above mentioned points are strictly observed. If you
don't the results will not be the best.
We will suppose that you intend doing your own
photographing and that you have the necessary equip¬
ment at hand. Set the camera on the tripod, open it
and slide the bellows out. Point the camera at the
print to be photographed, about one foot away from
it. Set the shutter on "Time" or "T," as it is indicated
on most cameras, and then open it by pressing the
bulb or release. Open the door at the back of the
camera to bring the ground glass into view. See that
the largest diaphragm opening is in the lens. Look on
the ground glass; do not try to look through it. Then
see if the print shows. Use a focusing cloth. This
should be thrown over your head and the back of the
camera to shut out all the light except that coming
through the lens illuminating the ground glass. The
print will probably show as just a blur, or will not be
LESSON TEN 7
visible at all. Reach around to the front of the cam¬
era with your right hand and move the front back
and forth, along the track it runs in. Watch the
print. At one point it will show the clearest. If the
print will not show clearly on the ground glass at any
position of the bellows, move the entire camera
farther away from the print or closer to it. At one
point the print will show sharp and clear on the
ground glass. It should be about the same size as the
finger print impression being photographed. When
it is, and the ridges show sharply, you have the cor¬
rect focus. Do NOT try to photograph the finger
print larger than natural size.
The exposure is the next consideration. This de¬
pends entirely upon the intensity of the light, the size
of the diaphragm opening used, and the speed of the
emulsion on the plate. The correct exposure to be
given is probably the most uncertain factor the pho¬
tographer has to contend with. The light is always
varying in intensity, so the exposure will very seldom
be the same. For this reason the use of artificial light
is probably the most satisfactory, especially for the
beginner. Use two nitrogen mazda lamps of 500
watts each. Place one on each side of the print to be
photographed, slightly forward of it. Have them far
enough out so that the light itself will not show in the
ground glass. Using the smallest stop in the dia¬
phragm and a slow plate, an exposure of fifteen
to thirty seconds will be about right. No other light
than that from the electric bulbs should reach the
plate. In other words the rest of the room must be
dark. An outfit of these lights can be made portable
fi THE SCIENCE OF FINGER PRINTS
so that prints may be photographed at the scene of a
crime. Use reflectors back of the lights so as to con¬
centrate the light on the prints. : •
If you prefer to-use daylight, it is suggested that
you purchase a Wàtkins Bee Exposure Meter from
any photographic supply house. With its use you are
practically certain of good results. ■ ~ ■
To continue with the photographing of the print;
after you have secured the proper focus, close the
shutter by again pressing the shutter release.
Take a plate holder containing a plate. You can
have the plate inserted in the plate holder by a photog¬
rapher or you can do it'yourself." If you insert the
plates yourself you must have a darkroom. The dark¬
room will be discussed later. Insert the plate holder
in the camera. See that it fits properly, then draw
the slide out. Open the shutter and after exposing
the proper length of time, close it. Replace the slide
into the plate holder with the "Exposed" side out.
Then remove the plate holder from the camera.
When photographing a developed latent print
which is not very distinct, you might experience some
difficulty in securing a sharp focus. If a card con¬
taining printed matter is placed alongside of the print
to be photographed, and the camera focused on the
edges of the letters, the focus will be sharp for the
print. Remove the card before exposing for the fin¬
ger print.
Quite a bit of manipulation will be necessary to ob¬
tain a good photograph of a latent finger print which
has not been developed. By examining from different
angles, determine in just what position the light
FIGURE 2.
10 THE SCIENCE OF FINGER PRINTS
throws the print into visible relief.—Place your cam¬
éra in th,at position and look on the^ground glass.;' If
the ridges do not show, manipulate the camera to;
point at the print in different positions, until the
ridges do show. It may tax your patience before you;
get just the right angle, but you must learn to be pa-1
tient to succeed. When photographing do not fail to
use the smallest diaphragm stop. Fig. 2 shows a
latent palm print which was found on the fender of an
automobile from which accessories had been stolen,
also a finger print on a safety deposit box which had
been rifled. These undeveloped latent prints were
photographed by manipulation as explained above.
The theory of photog'raphy can be briefly stated as
follows : Light is allowed to act on a sensitized plate.
This plate holds silver bromide, suspended in gelatine.1
The silver bromide is sensitive to light, and is affected
by it to the extent that the bromide of silver turns to:
the black metal form, when acted upon by certain
chemicals. The camera is composed of a telescopic
bellows, excluding all light except that which comes
through the lens. In front of the bellows is an open-;
ing across which the lens is fitted. This lens has the:
dualities of reducing the rays cast into it from an
image, and reflecting these rays to the plate in propor¬
tion, but smaller. The closer the lens is to the object
and the further from the plate in the back of the cam¬
era, the larger will be the image produced, and vice
versa. Light colored objects reflect more light than
dark colored objects, and thus when reflected on to the
plate, the bromide of silver in parts of the plate re¬
ceiving the greatest amount of light will turn darker
LESSON" TEN II
than those receiving a less amount. Red and black
objects which reflect practically no light at all, will not
affect the bromide on the plate, and will naturally be
reproduced as white, or transparent. The shutter reg¬
ulates the time the light is allowed to act on the plate,
and the diaphragm regulates the quantity of light al¬
lowed to act on the plate.
The negative, as the name implies, will show color
values just opposite what they really are. To secure
a positive, this trasparent negative is placed over a
piece of paper sensitive to light the same as the plate.
Light is allowed to act on it, and when developed, the
result on the paper will be a positive showing true
color values as the light passed through the trans¬
parent parts of the negative, and not through the
opaque parts.
The Eastman Kodak Company has manufactured
a special camera, designed solely for finger print pho¬
tography. This camera is illustrated in Figure 3.
All that is necessary to operate it is to place the square
opening at one end of it over the print to be photo¬
graphed. (A latent finger print must be developed
before it can be photographed with this camera.) The
shutter is released and the rest is automatic. It car¬
ries its own source of light so the exposure is prac¬
tically constant.
Some difficulty will be encountered when photo¬
graphing prints from bottles, electric light bulbs, can¬
dles, etc., in fact all rounded surfaces. The ends of
the print will be further away and at an angle from
the camera when it is focused on the center part of
the print. The difference in the distance can be over-
12 THE SCIENCE OF FINGER PRINTS
come by using" a small diaphragm opening or stop,
thereby increasing the depth of focus. The other
fault cannot be corrected. If you have to photograph
a print on such a rounded surface, focus on the most
important portion of the print, that is, the part show¬
ing the most salient characteristics, and photograph
that part. The ridges around the edges of the print
farther from the camera will appear crowded or run
together in the photograph.
After a print has been developed on a glass bottle,,
fill the bottle with a liquid, colored in contrast to the
powder used on the latent print. On electric light
FIGURE 3.
bulbs, the glass can be painted, in back of and around
the print, in contrast to the color of the powder used
in developing the print.
Impressions of finger print patterns left in can-
L KS SON" TKN' 13
dies or on pliable or plastic surfaces can easily be pho-
togra])hed without developing by using one sidelight,
throwing the alternate ridges and depressions into re¬
lief. They can then be developed by filling with
printer's ink the depressions or furrows which in this
case form the ridges, and again photographing.
In photographing prints left on mirrors, remove
the silvering from the back of the mirror directly op¬
posite the print, and treat in the same manner as plain
glass. Another way is to paint the mirror a dull black
all around the edges of the print. Practical results
have proven the first method to be the most success¬
ful, however.
If you intend to do your own work you will need a
darkroom, regular or improvised. This darkroom
should be made so that all light can be excluded. A
dark ruby light is used for illumination, when develop¬
ing plates, printing pictures or changing plates into
the plateholders. If you do not care to go to the ex¬
pense of constructing a regular darkroom, or the cir¬
cumstances will not permit, you can probably impro¬
vise some room to suit the purpose. The kitchen or
bathroom will do at night. The prime requisite is that
no white light enter the room and strike the sensitive
surface of the plate or paper. A streak of light, how¬
ever small, will fog the plate if the light strikes the
surface of it.
We will suppose that you have improvised some
room for use as a photographic darkroom. You will
then require paraphernalia, consisting of three trays,
each slightly larger than the size of the plate used,
one pound of acid hypo, several tubes of developer, one
eight ounce graduate, a stirring rod and a drying rack.
14 THE SCIENCE OF FINGER PRINTS
To develop a plate, mix the contents of one of the
tubes of developer in the required amount of water,
usually four or eight ounces. The directions will be
found on each tube. Leave the developer in the grad¬
uate. Prepare eight ounces of hypo fixing solution,
according to directions on the package. To develop,
turn out all lights but the ruby light, place the plate,
emulsion side up in the developer tray, and pour the
developer over the surface of the plate. Quickly rock
the tray from side to side, expelling any air bubbles
that might have formed. The plate will begin to dark¬
en. Rock the tray continually throughout the entire
process of developing. From time to time remove the
plate from the developer and examine it before the
ruby light. When it appears to be fully developed re¬
turn it once more to the developer and leave it for
about thirty seconds. The plate should then be
thoroughly rinsed in clear water and then placed in
the fixing bath. The gelatine, which appears a milky
white from the back of the plate after it comes out of
the developer, will be dissolved by the hyposulphite of
soda. When thoroughly fixed and transparent, the
plate should be washed for one hour in running water
and then placed in the racks to dry.
Prints are made in exactly the same way as the
plate was developed. After the plate is dry, place it
in a printing frame, emulsion side inward. The sen¬
sitized paper is placed emulsion side against emulsion
side of the plate. Clamp the back on and expose to a
white light for fifteen seconds. If the plate is very
dense use a thirty-second exposure. Remove from the
frame and develop exactly the same as the plate, elim-
LKSSOX TEN 1".
inating the extra thirty seconds in the developer, as a
print does not fix out the same as a plate does.
Plates should be inserted in the plate'holders with
the emulsion side outward. The emulsion side can
easily be determined in the darkroom by pressing the
lips over one corner of the plate. The lip will stick to
the emulsion side. Do not touch the surface of the
plate with the fingers. Always handle it by the edges
only.
In developing plates of finger prints be extremely
cautious to have every article very clean. A speck of
dirt catching onto the plate of a finger print might
form what could be taken for a characteristic in the
print. ..•«-■ i
For presentation in court, the finger prints need
to be enlarged. You can do this yourself if you care
to go to the expense of purchasing an enlarging cam¬
era. If not, any photographer will be able to make
an eight inch by ten inch enlargement for you from a
good negative. The 8 by 10 size is that usually used
for court work.
Photography is a science and a profession in itself.
You will not necessarily need to learn all about it to be
successful, but the more you learn about every phase
of finger print work, the more expert you will become,
and you will rise more rapidly to the pinnacle of suc¬
cess, and thus earn larger fees. If you desire to learn
more about photography than the specialized and ele¬
mentary account given in this lesson, write to the
Eastman Kodak Company, Rochester, Xew York, or
to Burke & James, Chicago, 111., for a list of books on
the subject.
16
THE SCIENCE OF FINGER PRINTS
Examination Questions on Lesson Ten.
1. What is the theory of photography?
2. What are the essentials of a camera capable of
photographing finger prints?
3. What kind of a lens is best for finger print
photography?
4. What is the function of the diaphragm?
5. Should a slow or fast emulsion plate be used?
6. How can a latent print be photog'raphed before
it has been developed?
7. Summarize the process of developing a photo¬
graphic plate.
8. Is it necessary to enlarge finger print photo¬
graphs for use as evidence in court?
9. To what size should they be enlarged?
■ 10. What is the value of the ground glass focus¬
ing screen ?
Your answer to each question will count for ten
per cent.
PUTTING YOURSELF ACROSS.
INothing can be put across in this world without enthusiasm.
INo fame—no name has ever been gained except through belief, backed
"by that whole-hearted, earnest effort which makes long hours pass quickly
and hard work a pleasure.
Unless you have, first and last, an abiding faith in your studies and in
your ability—you cannot successfully carry out your purpose.
Enthusiasm is the connecting link between you and the world.
It carries you forward with a rush, overcomes obstacles, surmounts dif¬
ficulties, beats down opposition and gains your goal.
Enthusiasm is the key which opens the hearts of the world's people.
On the baseball field, the battle front or in the busy ways of the trades
and professions—it's all the same. People like pep, and their plaudits and
rewards are for the fel'ow who goes at it heart and soul. *
So do not permit your interest in your studies to lag. You can sustain
that interest by keeping at your lessons regularly every day and you will
have the incentive to study your lessons every day if you will always keep
in your mind's eye that goal you are striving for—the day you receive
your diploma from the Dunlap School of Finger Prints and start your
wonderful career as a full-fledged finger print expert.
THE SCIENCE
of
FINGER PRINTS
Lesson Eleven
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Eleven
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON ELEVEN
Classification Review
In previous lessons the subject of finger print classi¬
fication was covered. You learned that a set of prints
is composed of the impressions of all ten fingers ap¬
pearing in natural sequence, the right hand above the
left hand; the left hand thumb, index, middle, ring
and little fingers appearing directly under the corre¬
sponding digits of the right hand. You also learned
that each set of prints must be given a classification
formula by which the set is systematically filed. This
formula is composed of two, three or four parts, all
depending upon the types and formation of the pat¬
terns composing them.
Let us first review the definitions of the eight types
of finger print patterns, very briefly, to refresh your
memory.
The true arch is the most simple of all formations.
The ridges forming the arch extend from one side of
the pattern to the other in parallel rows. Usually the
ridges bend upward slightly at their middle, in the
form of an arch.
The tented arch is a modified form of the plain
arch. In the tented arch the ridges bend upward
abruptly in the center, forming a very pronounced
peak or barb, somewhat like a tent.
The exceptional arch will occasionally cause some
trouble. The exceptional arch verges on the loop
type. That is, it may contain a well defined delta but
no recurving ridge, or else a recurving ridge but no
, delta.
The loop consists of one or more ridges entering
the pattern from one side, bending or arching around
at the summit, retracing their courses and terminat¬
ing on the same side as they entered. This entire
loop formation must be located on one or on the same
side of the delta.
4
THE SCIENCE OF FINGER PRINTS
Loops are further sub-divided into radial and ulnar,
depending on the slope of the ridges forming the loop.
If, in an impression of a loop from the right hand, the
ridges slope from right to left, the loop is radial. If
the ridges forming the loop slope from left to right
in a loop print from the same hand it is an ulnar loop.
On a left hand loop print, if the slope is from left
to right it is a radial loop and from right to left, ulnar.
A whorl is a pattern containing two deltas, one on
the right and the other on the left. The ridges un¬
wind spirally from the center, or form concentric
circles about the core. One ridge must make at least
one complete circuit about the core or pass through
an arc of 360 degrees in order to fill the requirements
of this type.
Composites are finger print patterns containing
two or more deltas. As the name implies, they are
composed of two or more patterns combined in one.
The central pocket loop is a pattern of the compo¬
site group. It is made up of a loop enclosing a small
whorl or recurving ridges. There are usually only
two deltas, one outside of the loop and the other
enclosed by it. This ridge formation inside of the
loop must be made up of at least one ridge which re¬
curves, that is, one that is circular or rounding in
form, and which passes between the core or center of
the pattern, and the delta formed inside of the loop,
at right angles to the axis formed by the ridges of the
loop in the direction that they enter the pattern.
The lateral pocket loop is also of the composite
type, usually containing only two deltas. It is com¬
posed of two distinct loops, one of which surrounds
or overlaps the other. The core or center ridges of
both loops must terminate on the same side of either
the right or left delta.
A twinned loop, also of the composite type, closely
resembles the lateral pocket loop. It is also composed
of two distinct loops, one of which overlaps or sur-
LESSON ELEVEN
S
rounds the other. However, the termination of the
central ridges of both loops is on opposite sides of
either delta.
The accidental is the last of the composite type.
Any pattern containing at least two deltas, having
no regular ridge formation whereby it can be classi¬
fied as a whorl or any other of the three composite
patterns, is called an accidental. That is, any con¬
glomeration of ridges or patterns with two or more
deltas is an accidental.
The primary classification is the first and most im¬
portant given to a set of prints. It is made up of a
numerical fraction. The ten fingers are placed in pairs,
each pair forming a fraction expressed in the standard
symbols describing that type of pattern. The right
thumb and index finger form the first pair, the second
pattern being written as the numerator and the first
as the denominator. The right middle and ring fin¬
ger patterns form the second pair and fraction, being
written as ring finger over middle finger. The right
little finger and left thumb form the third pair, writ¬
ten left thumb over right little finger, etc. Numbers
are assigned to all the whorls and composites. Arches,
tented arches and ulnar loops receive no numerical
value. Whorls or composites appearing in the first
pair, numerator and denominator, receive the value
of sixteen. In the second pair numerator and de¬
nominator, eight; in the third pair, four; in the fourth
pair, two; and the fifth or last pair, one. All the
numerator values are added together, likewise the
denominator numbers. The result is written as one
fraction. To this, a value of one is added in both
numerator and denominator, the result being the pri¬
mary classification.
The second division for filing is by the sub-classifi¬
cation. This may be either lettered or of the whorl
type, depending upon the type of patterns contained
in the indices.
6
THE SCIENCE OF FINGER PRINTS
In the sub-classification the right hand forms the
numerator, and the left hand the denominator. The
sub-classification is also expressed in fraction form,
except that it is with the use of letters instead of
figures.
As has been stated, the indexes are the key of the
sub-classification. If both are loops, arches or a com¬
bination of a loop and an arch (tented arches in¬
cluded) the set will have a lettered sub-classification
This is shown by the symbols written as a fraction.
The index fing-ers are written as capitals. Arches,
tented arches and radial loops only are considered
before and after the indexes in the sub-classification.
They are exhibited in the formula by lower case let¬
ters, written before and after the index finger sym¬
bols. Ulnar loops are not considered except in the
first fingers. When two or three arches, tented
arches or radial loops appear consecutively after the
indexes they are written in the formula as "2a," "3t,"
"3r," etc. If two arches, tented arches or radial loops
appear in the middle and little fingers separated by a
whorl, composite or ulnar loop in the ring finger, they
are written as "2a," "2t" or "2r," disregarding the
pattern of the ring- finger altogether.
If a whorl or composite appears in either or both
indexes, that set will have a whorl sub-classification.
Ridges are traced in whorls, from the left to the right
delta, to determine whether they are inner, meeting
or outer. This sub-division is represented as I, M and
O in the formula. If both index and middle fingers
are whorls the ridges are traced in all four fingers.
If the index and middle fingers are of different types
only the indexes are considered. If one index finger
is a whorl and the other a loop, the ridges are traced
in the whorl and counted in the loop. The loop count
results as inner or outer, and is represented in the
formula as I or O.
In case of a lettered sub-classification of
LESSON ELEVEN
7
U R U R
—, —, — or —, where no arches, tented arches or
U U R R
radial loops appear before or after the index, such a
set will have a secondary, or second sub-classification.
This secondary classification is the result of ridge
counting in the loops of the index, or index and mid¬
dle fingers. Where the index and middle fingers are
of different types, ulnar and radial loops being con¬
sidered as of the same type, only the indexes of either
hand are considered. The result of ridge counting
is exhibited as I and O in the formula.
The final classification is the number resulting from
counting the ridges between the core and delta of the
loop in the right little finger when such pattern is an
ulnar or radial loop. The number is shown in the
numerator of the formula, being written as the last
part of it. If the right little finger is not a loop, use
the left little finger and write the result in the denom¬
inator of the formula. In case no loop appears in
either little fing-er, the final classification is omitted.
On all standard finger print cards space is reserved
in the upper right hand corner for inserting thè classi¬
fication formula of that set of prints. The words
"finger print formula" are either spelled out in full or
abbreviated, as "F. P. formula," followed by a line.
This line serves as the division of the numerator and
denominator of the formula. The primary classifica¬
tion is written first on this line, the numerator above
and the denominaor below. Following this is the sub-
classification, which will be either lettered or of the
whorl kind. In a set of prints where the lettered sub-
classification represents the index fingers only, that
set will have a second sub-classification, which will
follow the lettered sub-classification resulting from
the symbols representing the index finger pattern.
The final classification appears last in the formula.
Following are examples of various written formulae:
8
THE SCIENCE OF FINGER PRINTS
1 aRa 16 32 10 1 U 10 10
1 Aa ' 32 MM 1 U 01
We will take several sets of prints, bringing out
the various forms of classification, and starting at the
beginning, work out the complete formula, explain¬
ing each step as we go along.
For the first example take the set illustrated in
Fig. 1.
NAME ' ! F. P. FORM Cl. A
Figure 1
In this set the right thumb is a very plain arch, as
is also the right index finger. The right middle finger
is an ulnar loop, likewise the right ring and little
fingers.
The left hand prints are all loops, the thumb being
radial and the remainder ulnar. We then mark each
print with its standard symbol as you did with the
sets you made up for the fourth and fifth examina¬
tions.
We know by glancing over this set, that the pri¬
mary classification will be 1, as no second group pat-
1
terns appear. The index fingers are the foundation
of the sub-classification, so they must first be exam-
LESSON ELEVEN
9
ined for the sub-classification. Bear in mind that the
fingers are not paired off for the sub-classification as
they were for the primary. The right hand forms
the numerator and the left hand the denominator.
The indexes are both of the first group so this set
will have a lettered sub-classification. The right in¬
dex finger is an arch and so is written as "A" in the
numerator of the formula. Continuing to the left
index finger we find an ulnar loop, which expands our
formula to A. Looking for arches, tented arches and
U
radial loops, before and after the indexes, we find an
arch in the right thumb. Inasmuch as it appears be¬
fore the index finger it is written with a lowercase
letter, further enlarging the sub-classification to aA.
U
As no arches, tented arches or radial loops follow the
right index finger we must pass to the left hand. The
left thumb is a radial loop and as such is written as a
small "r" preceeding the capital "U" of the left index
finger. As none of the patterns considered follow the
left index finger the complete letter sub-classification
will read aA.
rU.
The last part is the final classification, or the ridge
count of the right little finger. This is thirteen.
The complete classification formula for this set,
therefore, will read 1 aA 13.
1 rU
Taking the set illustrated in Fig. 2, we will work
out its complete formula as we did in the first set.
The right thumb is a double spiral whorl, so a "W"
is written under it. The index finger is also a whorl
and is therefore designated by a "W." The middle,
10
THE SCIENCE OF FINGER PRINTS
K1CIIT 1IANI>
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIOOLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
%
P
u
3
I.EKT IIANIi
6. LEFT THUMB
7. 1. FORE FINGER | 8. L. MIDOLE FINGER | 9. L.RINGFINGER
10. L. LITTLE FINGER
S
W
S
ÄSU
m
Figure 2
ring" and little fingers of the right hand are also
whorls. The symbols are written for these in the
same way. The left thumb is an ulnar loop, so the
ulnar loop symbol, sloping from right to left likewise
is written underneath for the left index finger. The
remaining left hand patterns are whorls.
As several whorls appear in this set it will have a
high primary classification. Making out a letter frac¬
tion for it, composed of the symbols, the result is
(1) (2) (3) (4) (5)
w w w w w
. Pairing off this fraction,
//WWW
(6) (7) (8) (9) (10)
using the second, fourth, sixth, eighth and tenth fin¬
gers as a new numerator and the first, third, fifth,
seventh and ninth fingers as a denominator, we have
(2) (4) (6) (8) (10)
W W / W W
as a result the new fraction .
WWW / W
(1) _(3) (5) (7) (9)
To this paired off fraction are assigned the number
values. The whorls in the first pair, numerator and
LESSON ELEVEN
11
denominator, each get a value of 16 or 16. The whorls
16
in the second pair, numerator and denominator, get
a value of 8 each. The two are combined to read
16 8. The numerator of the third pair is a loop, so it
16 8
gets no value. The denominator is a whorl with a
value of 4, and enlarges the fraction to 16 8 0. The
16 8 4
numerator of the fourth pair is a whorl with a value
of 2. The denominator is a loop and therefore re¬
ceives no value. The fraction becomes 16 8 0 2.
16 8 4 0
The numerator and denominator of the fifth
or last pair are both whorls with a value of 1.
The complete fraction becomes 16 8 0 2 1. Adding
16 8 4 0 1
the numerator values, then the denominator values 27
29
results. The customary 1 fraction is added to this
1
total, making 28 the primary classification for the set.
30
The sub-classification for this set is the next con¬
sideration. As a whorl appears in the rig-ht index fin¬
ger it is evident that this set will have a whorl sub-
classification. The right index and middle fingers
being of the same type, both are considered. Tracing
of the ridges in the whorl of the right index finger
shows it to be inner. The ridge emanating from the
12
THE SCIENCE OF FINGER PRINTS
left delta, when traced to the right, passes inside of
the right delta with more than two ridges interven¬
ing. A capital letter "I" is inserted above the right
index finger pattern in the space allotted to the sym-
mols /. The right middle finger is likewise inner.
The left index finger being- a loop, the ridg-es are
counted between the core and the delta. As there are
more than nine it is an outer loop. A capital "O" is
placed above it, as in the case of the right index and
middle fingers. The left middle finger being of a dif¬
ferent type than the index, it is not considered. The
sub-classification formula therefore is I I.
O
The little fingers on both hands are whorls so there
will be no final classification in this set.
The complete classification formula will read 28 II.
30 O
For our next example take the set illustrated in
Fig. 3. This set of finger prints is composed entirely
NAM F I F P FORMl'LA
F. P No LEDCFR No ' REF
RICHT HAND
Figure 3
LESSON ELEVEN
13
of first group types. The primary classification will
necessarily be 1.
1
As the indexes are both of the first group, this set
will have a lettered sub-classification. Writing the
symbols of both indexes in capital letters to form this
sub-classification we get R.
U
No arches, tented arches or radial loops appear be¬
fore or after the indexes so R completes the sub-
U
classification. 1
To further break up accumulations of the sub¬
group R a secondary classification is employed. This
U
was discussed in one of the previous lessons. This
secondary classification is composed of the resulting
"I" and "O" of the ridge count of the loops in the
index and middle fingers. As both the index and
middle fingers of both hands are all loops in this case,
they must all be considered.
The count of the ridges between the core and delta
of the right index finger places it in the outer class,
as more than nine ridges intervene. More than ten
ridges appear between the core and delta of the loop
in the right middle finger, classing it as outer. Ex¬
hibiting it by the symbols, 00 is the result.
10
The right little finger is an ulnar loop, so its ridge
count will form the final classification. There are
twenty-one ridges between the core and delta so the
numeral "21" is written at the end of the formula,
above the line.
14
THE SCIENCE OF FINGER PRINTS
The complete formula for this set when written out
1 R 00 21.
will read
1 U 10
Sometimes the final classification, if it be the ridge
count of the right little finger, is written at the end
of the numerator and denominator dividing line
midway between the numerator and denominator
1 R 00
position as 21. - -
1 U 10
Figure 4 illustrates a set of prints in which the
secondary classification is composed of the ridge
count of the index fingers only. The middle fingers
are of different types than the indexes, so the indexes
only are considered. No arches, tented arches or
radial loops appear before or after the indexes, and
as both indexes are loops, this set will have a sec¬
ondary classification.
Dopt. No
-
RICHT llANl»
SI
Jit '
121
ÄÄS|
m
WAS*1
JBlÊi
-
IHH
SáH •
m»-
S
Figure 4
Figure 5 illustrates the classification of a set of
prints containing amputations, the right and left in¬
dex fingers being the ones missing. Remember that
the abbreviated form of the word, "amp.," is written
in the space allotted to those fingers. As both of these
LESSON ELEVEN
IS
_ LEDCER No
F. P. FORMtXA_.
RE F
1. RIGHT THUMB
Z R. FORE FINGER
3. R. MIOOLE FINGER
S. R. LITTLE FINGER ,
J!
gïûli
II
S. LEFT THUMS | 7. L. FORE FINGER | I. L. MIOOLt FINGER | ». L. RING FINGER j 10. L. LITTLE FINGER
in
mi jpj
--
Figure 5
corresponding fingers are missing they are classi¬
fied as meeting whorls. This insures a whorl sub-
classification. Both middle fingers also being whorls,
all four are considered. Ridge tracing of the middle
finger whorls proves one outer and the other inner.
Combining their symbols with the index finger sym¬
bols, results in the sub-classification formula MO.
MI
The complete formula for this set will be
31 MO 15
(Amp.)
12 MI
Examination on Lesson Eleven
Work out the complete classification formula for
the five sets of prints reproduced on the following
pages. On the regular examination paper blank write
out the complete classification for each, in the regular
formula form. Number each answer to correspond
with the number of sets illustrated. Each answer will
count for 20 per cent of your grade on this lesson.
16
THE SCIENCE OF FINGER PRINTS
Set Number One
Set Number Two
LESSON ELEVEN
17
Set Number Four
18
THE SCIENCE OF FINGER PRINTS
Set Number Five
THE SCIENCE
of
FINGER PRINTS
Lesson Twelve
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Twelve
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON TWELVE
Filing and Searching
There are two kinds of finger print filing cabinets
in use at the various bureaus throughout the country.
The oldest type of cabinet is the open shelf or pig-eon-
hole style; the newer style is the vertical drawer file.
The open shelf file is still used in the large central
government bureau at Leavenworth, Kansas, and
also at the central New York city police department.
This .style of filing cabinet consists of a series of
shelves, arranged horizontally. At regular intervals
the shelves are partitioned off by upright sides. The
general appearance of the'cabinet resembles a post¬
man's sorting box. . The construction is extremely
simple and inexpensive. The horizontal partitions or
shelves are about four inches apart and seventeen
inches deep. The vertical partitions are eight inches
apart. Each pigeon-hole, therefore, is seventeen
inches deep by four inches high and eight inches wide.
The filing cards used for this style of cabinet are of
thin material, a trifle smaller than the size of the file
compartment. This style of card was probably
adopted many years ago when the science was yet in
its infancy. The rolled impression spaces on these
cards are twice as long- as on the square cards. If the
operator made a poor impression in the upper half
of a space, he could take another print below it, and
in that way avoid making a whole new set of prints.
These long records are filed flat in the compart¬
ments. A stiff cover is used to hold them together.
The records between two covers are therefore called
books. The primary classification was sub-divided
by ribbon indexes, overlapping the ends of the rec¬
ords.
The objection to this style of finger print filing
cabinet is that the records accumulate dust and dirt
very rapidly by reason of the open forward end. The
4
THE SCIENCE OF FINGER PRINTS
record cards, being of thin stock, will not stand a
great amount of handling and soon become very
ragged and unwieldy. It is also much harder to look
through this kind of a collection as the paper on
which the records are contained is so thin. Each rec¬
ord must be flipped over with the thumb and fore¬
finger. After a book has been looked through a num¬
ber of times, the upper right hand corners, where the
formula appears, becomes very bent and wrinkled by
reason of flipping them between the fingers.
The old open style of filing cabinet has in recent
years been supplanted by the vertical drawer files.
Stiff bristol cards, such as were furnished you in the
outfit, are filed vertically in the drawers. That is,
they are stood on end. The sub-division guides are
also in the form of cards, a little larger than the reg¬
ular records, standing visibly above them. The sub¬
divisions are plainly marked on these cards.
Finger print records are kept in a much neater,
cleaner condition in these drawer files than in the
other type. The cards being heavier, they will stand
a great deal more handling, and being thicker, there
is not so much chance of a record being missed or
passed over, when turning them over. Taking every¬
thing into consideration, the drawer files are a great
improvement over the open shelf files. While the old
style serves the purpose, we advocate the use of the
new kind. It is used nearly everywhere. Our text is
therefore based upon its use.
In the lesson on primary classification, the student
learned that there are one thousand and twenty-four
primary classifications in the Henry system. From
this, one might reasonably deduce that a filing cabinet
with one thousand and twenty-four drawers would
be necessary to accommodate them all. On second
thought the inadvisability of such an unwieldy cab¬
inet becomes apparent.
In files containing about fifty thousand finger print
LESSON TWELVE
5
record cards, an eight drawer file is sufficient. To
accommodate all the primary classifications, an aver¬
age of one hundred and twenty-eight primary classi¬
fication combinations will have to be contained in
each drawer.
The student also learned in a previous lesson that
about sixty-five per cent of all finger print patterns
are loops. As loops receive no numerical value in the
primary classification, it is obvious that a large por¬
tion of records in a collection will have a primary
classification of 1. For this reason a larger space
1
must be reserved in the files for them. In an eight
drawer file, one whole drawer should be reserved for
the one-over-one primary division.
Nearly one hundred and fifty primary divisions will
have to be contained in each of the seven remaining
drawers. The denominator forms the first order of
filing in the entire classification system. The second
order is chronological, according to the size of the
number composing the denominator of the primary
classification. Thus 2 would follow 1, and 3 would
1 1 1
follow 2, etc., up to 32, 32 being the highest primary
1 1
number possible. Following 32, the denominator
1
will change to 2, and the numerator back to 1, as 1
2
to 32. The denominator then changes to 3 as 1 to 32.
2
6 THE SCIENCE OF FINGER PRINTS
A file drawer, in order to contain one hundred and
fifty primary divisions, arranged chronologically,
would have to be marked as 1 to 22. That is, it would
2 6
contain all the following primary divisions:
• J., 2, 3, etc., to 32 = 32
2 2 2 T
J_ to 32 = 32
3 3
JL_ to 32 = 32
4 4
J_ to 32 = 32
5 S
1 to 22 = 22
~6 6~
32+32 + 32 + 32 + 22 = 150
Therefore, on the outside of the second file
drawer, an index card would be placed, marked 1 to
2
22 23 12 .
—. The third drawer would be marked , the
6 6'11
13 2 3 24
fourth drawer , the fifth drawer —-, the
11 ' 16 16 20
25 14 15 4
sixth drawer , the seventh drawer , the
20 25 25 30
5 32
eighth and last drawer .
. . 30 32
' You will note that the last drawer contains only
LESSON TWELVE
7
eighty-four primary divisions. The extra space will
be taken up by sets with a 32 primary classification,
32
1
as this division will be next in size to the —.
1
The primarv classifications are arranged in the
1
drawers, starting at the top, left hand drawer with —,
1
down the vertical row on the left side of the cabinet.
The bottom drawer in the first row is followed by the
top drawer in the second row, etc.
The inside of each drawer will be sub-divided by
guides, bearing each primary division, arranged in
chronological order.
Two different colored card guides should be used,
one marking the chang-es iii the numerator division,
and the other the denominator divisions. It is a good
idea to use white for the numerator and blue for the
denominator. Thus in the second drawer the first
card would be a blue one bearing the number 2. Fol¬
lowing this, white index guides numbered from one
up to thirty-two will be arranged consecutively.
After the thirty-second white guide a blue one bear¬
ing the number three is placed, then white guides
again numbered from one to thirty-two, etc.
In a fifty thousand card collection, each primary
group will be so small that no sub-division guides will
be necessary except in the 1 drawer. This should
1
be sub-divided by the regular sub-division and sec¬
ondary guides.
Regardless of the fact that no sub-division guides
are used in a fifty thousand collection, the complete
8
THE SCIENCE OF FINGER PRINTS
classification formula should always be made out.
The records are arranged according to the sub-classi¬
fication, even though no guides are used. Also, room
must be left for expansion, because the files will con¬
tinue to grow and sub-classification guides will
eventually be incorporated in the files.
The larger the collection the more the sub-division
guides will be necessary. Under all primary head¬
ings requiring tented arch, radial and ulnar loop sub¬
divisions, these are arranged in the order of "A," "T,"
"R" and "U." As was previously explained, the index
fingers are the key of the sub-classification. That is,
the patterns of the indexes determine the first order
of filing. The denominator forms the first order. Thus
A would be the first sub-classification guide, T the
A A
second, R the third and U the fourth, followed in
A ' A
ATRU ATRU ATRU
order by —, —, —, —, —, —, —, —, —, —, —, —.
TTTTRRRRUUUU
' In all collections of normal size, that is, from 15,000
to 20,000, these index finger markings will be suffi¬
cient. The sets are arranged between these guides,
in the order of "a," "t" and "r," first according
to thë denominator, and then the numerator, the
thumb pattern preceding the middle finger, the mid¬
dle finger the ring, etc. Thus a set of prints having
a sub-classification formula A, will precede one with
aA
a formula aA, and A will also precede A, and the
A aA Aa
LESSON TWELVE
9
last' formula of A will precede the first one of aA,
Aa A
because as just explained, the denominator forms the
first order or filing in the order of A, T, R, U. Like¬
wise rA3r would precede T, as the index finger pat-
rA3r A
terns have preference over all the others, and an "A"
in- the numerator precedes a "T," the denominators
of the .indexes of both classifications being the same.
In the same manner aRatr would precede aRa2r,
aUa2r aUa2r
because the "t" of the right ring finger pattern in the
first formula precedes the "r" in the right ring finger
of the second formula, the remainder of both formu¬
lae being identical.
Some of the lettered and sub-classified records will
require a final classification, that is, those containing
loops in the right little fingers. The arrangement of
the cards according to this final division is very
simple. Within each sub-classification section, the
cards are arranged numerically according to the size
of the number forming this final classification. Thus
a final classification of 1 will precede 2, and 2 pre¬
cedes 3, etc.
Under the 1 primary heading and a few others
1
where the index fingers are both loops, and no
Arches, Tented Arches or Radial Loops precede or
follow the indexes, a secondary sub-division is neces¬
sary in the files. The guides of the secondary
sub-division will follow the sub-classification guides
R U R U
R RU' U'
10
THE SCIENCE OF FINGER PRINTS
These secondary guides are also arranged so that
the denominator forms the first order of filing. The
second order of filing is I and O. If all the sec¬
ondary guides are incorporated in the files they will
read II, 10, 01, 00, II, 10, 01, 00, II, 10, 01,
II II II II 10 10 10 10 01 01 01
00, II, 10, 01, 00. In smaller collections it will
Ol ÖÖ 00 00 00
not be necessary to use guides for all the sub-divi¬
sions. Four can be used, showing the denominator
change only. The numerators are filed in bàck of
them in the prescribed order. These four index guides
will be marked II, 10, OI and 00, will be arranged
in the order shown. In other words, the four numer¬
ator combinations possible with the "II" denominator
will be filed in the order of II, 10, OI and 00 in back
of this guide, etc.
Under the headings where the secondary guides
are used, the final classification will appear last.
The whorl sub-classification guides will have to be
placed under other primary headings. The denom¬
inator forms the first order of filing in the whorl sub-
classification as it did in all others. The arrangement
is secondly made in the order of I, first; M second,
and O, last. There are eighty-one possible combina¬
tions in the whorl sub-classification, when both index
and middle fingers are considered, and nine combina¬
tions- when only the two indexes are sub-classified.
All of them will not have to be used in other than
unusually large collections. These eighty-one are
II, TM, 10, MI, MM, MO, 01, OM, 00, II,
II II II II II II II II II IM
IM, 10, MI, MM, MO, OI, OM, 00, II, IM,
IM IM IM IM IM IM IM IM 10 10
LESSON TWELVE
11
10, MI, MM, MO, 01, OM, 00, II, IM, 10,
10
10
10
10
10
10
10 MI
: MI MI
MI,
MM, MO,
Ol,
OM,
00,
II, IM,
10, MI,
MI
MI
MI
MI
MI
MI
MM MM
MM MM
MM.
, MO,
Ol,
OM,
00,
II,
IM, 10,
MI, MM,
MM
MM
MM
MM
MM
MO MO MO
MO MO
MO,
Ol,
OM,
00,
II,
IM,
10, MI, MM, MO,
MO
MO
MO
MO
Ol
Ol
Ol Ol
Ol Ol
Ol,
OM,
00,
II,
IM,
10,
MI, MM,
MO, Ol,
Ol
Ol
Ol
OM
OM
OM
OM OM
OM OM
OM,
00,
II,
IM,
10,
MI,
MM, MO,
Ol, OM,
OM
OM
00
00
00
00
00 00
00 00
00.
00
Finger print records containing this type of sub-
classification are filed as shown in the above order.
The nine combinations for both indexes are I, M,
T r
O, o M, O, I, M, O.
1 M M M O O O
A guide is unnecessary for each one of these eighty-
one combinations, except in collections of a quarter
of a million or more. Use of the guides marked with
each of these nine combinations of the denominator
will be sufficient for the eighty-one combinations
shown above. In the same way, three guides showing
the three denominator changes when only the indexes
are considered, will be sufficient.
The cards are filed in the order shown for the eighty-
one possible combinations. Back of these are filed all
the exceptions. First, are the whorl sub-classifica¬
tions, where loops are involved. The combinations
possible where the right index and middle fingers are
loops and the left index and middle fingers whorls, are
n, io, oi, oo, il, io, oi, oo, n, io,
II " II II II IM IM IM IM 10 10
12 THE SCIENCE OF FINGER PRINTS -
01, 00, II, 10, 01, 00, II, 10, 01, 00,
10 10 MI MI MI MI MM MM MM MM
II, 10, 01, 00, II, 10, 01, 00, II, 10,
MO MO MO MO 01 01 01 01 OM OM
01, 00, II, 10, 01, 00.
OM OM 00 00 00 00
When the left index and middle fingers are loops,
and the right index and middle fingers are whorls,
the combinations will be the same, except that each
combination will be inverted, that is, the same denom¬
inators will become the numerators, and the numer¬
ators will be the new denominators. Record cards
falling under this group will be arranged in the order
given.
The right index finger being a loop and the left
index and middle fingers both whorls, another com¬
bination is formed. The above combination is re¬
versed when the left index finger is a loop, and the
right index and middle fingers are both whorls.
These two combinations will have the various "I"
and "O" subcombinations in the files.
Another combination is found when one index fin¬
ger contains a whorl, and the index and middle fingers
of the other hand both contain loops. A third com¬
bination is possible when one index finger is a loop
and the other index finger a whorl, both middle fin¬
gers being of other types than the two indexes. Then
there are the miscellaneous combinations of A, A, A,
rio
T, T, T, I, M, O, I, M, O.
IMOAAA TTT
The number of index cards to be used under each
change must be determined by the expert in charge of
the bureau. It will depend entirely upon the size of
the collection.
Cards containing amputations, blurs and deform¬
ities can be filed in a separate drawer or else in the
regular file.
LESSON TWELVE
13
Examination Questions on Lesson Twelve
1. Describe the two types of filing cabinets used,
pointing out the advantages of the new style over the
old.
2. In an eight drawer file, how much space should
be reserved for records bearing a 1 primary classifi-
T
cation ?
3. How are the primary guides arranged inside of
a small vertical drawer file?
4. How many primary combinations are possible
under the Henry system of classification?
5. What is the first order of filing under the Henry
system ?
6. What is the second order of filing in the lettered
sub-classification ?
7. What are the orders of filing in the secondary
classification? In the whorl sub-classification?
8. How many combinations are possible in the sec¬
ond sub-classification when both index and middle
fingers are considered? In the whorl sub-classifica¬
tion when both index and middle fingers are con¬
sidered ?
9. How would you mark the primary guides on the
outside of each drawer on a sixteen drawer cabinet?
10. How are finger print records arranged as to
final classification?
The student will be given a rating of ten per cent
on each of the above ten questions.
THE SCIENCE
of
FINGER PRINTS
Lesson Thirteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Thirteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON THIRTEEN
Filing and Searching—Continued
Mr. A. J. Renoe, the finger print expert in charge
of the central finger bureau at the federal pentiten-
tiary, Leavenworth, Kansas, has to contend with
large accumulations of prints in the sub-classes, and
has devised several means of breaking them up. This
bureau contains one of the largest collections of fin¬
ger print records in the country.
The two methods described in this lesson were de¬
vised by Mr. Renoe, and are used successfully in his
bureau. They were recently explained at the con¬
vention of the International Association for Identifi¬
cation and universally adopted by vote of the mem¬
bers.
A very large percentage of all finger print records
will be composed entirely or almost entirely of loops.
Very large accumulations will therefore accrue in the
1 R U R U
— section in the sub-classes —, —, — and —. The
1 R R U U
secondary classification by ridge count will break
these accumulations up to some extent, but not suffi¬
ciently in a large collection to facilitate rapid enough
search. To break up such largue accumulations, the
ridge counting of loops has been extended to include
the ring fingers of both hands. That is, the ridges are
counted in the loops of six fingers, the right and left
index, the two middle and two ring fing-ers.
The loops of the ring fingers are divided into inner
and outer, as are those of the index and middle fin-
g'ers. The ridg'e number limit, separating inner from
outer is raised one ridge, for the ring fingers. That
is, a loop with from one to twelve ridges between the
core and delta is inner. A loop having twelve or more
ridges appearing between the inner and outer termini
is classified as outer. The same symbols are used for
4
THE SCIENCE OF FINGER PRINTS
ring finger results as in the other digits. This exten¬
sion provides for forty-eight extra sub-divisions.
In other words, there are two possible combina¬
tions in each finger, inner and outer. In six fingers
there will be 26 or 2x2x2x2x2x2 or 64 possible com¬
binations, while when only four fingers are consid¬
ered there are 24 or 2x2x2x2 or 16 combinations.
Under this extension the cards are filed first accord¬
ing to denominator as usual, in the order of I and O
in the index, first; middle, second; and ring, third.
The other extension has to do with whorls. The
32
— primary division of the files will become crowded
32
before other intermediate divisions, and will also
necessarily need further breaking up. This is accom¬
plished by extending ridge tracing to the whorls of
the ring fingers. The same rules govern the ring
finger division into inner, meeting, and outer, as used
for the index and middle fingers.
This whorl extension provides six hundred and
forty-eight extra subdivisions. That is, three in each
finger, being I, M and O or 36 or 3x3x3x3x3x3 or 720
in all six fingers. This is 648 more than the 81 of the
two index and middle fingers.
The benefits to be derived from these two exten¬
sions are obvious. Many more combinations are pos¬
sible, which will break accumulations up into small
groups. The small groups greatly facilitate the
operation of searching and in that way save valuable
time.
Records are filed by a sort of elimination process.
That is, the drawer is located by the primary classifi¬
cation. The location inside of the drawer is deter¬
mined by elimination of the remainder of the drawer,
first by the sub-classification, then the secondary and
lastly the final.
Take for example a set of prints with a classifica-
LESSON THIRTEEN
S
13 R 10
tion formula of 16. In this formula 17 is
17 U 01
the denominator of the primary classification. In the
cabinets, look for a drawer with a 17 in the denom¬
inator on the index guide of the drawer. If the num¬
ber of drawers composing the cabinet is small, each
drawer will contain several primary classifications.
The guide will therefore bear the first and last pri¬
mary classification contained in that drawer. If you
are using an eight-drawer file this set will be con-
3 24
tained in the drawer marked about . The 17
16 20
denominator comes between 16 and 20. You Avould
therefore have to open this drawer and look for a blue
guide card bearing the number 17. This would be
immediately back of the first 32 white guide. Be¬
tween the blue guide 17 and 18 look for a white guide
marked 13. Between the white guide 13 and 14 look
R
for a sub-group guide marked —. In an eigfht-
U
drawer file, you would have no more sub-guides. In
R U
this bunch of cards between — and — would be the
U U
place for the card you have. Look for one with an OI
in the denominator. If you have no card with an
— secondarv denominator, deposit your record be-
01
tween one marked — and -— in the denominator. In
II OO
other words, bear in mind the order of filing, and
deposit the card in accordance with this order.
As another example take' a card with a formula
I rU2t
. This would be contained in the first drawer,
I aAr
6
THE SCIENCE OF FINGER PRINTS
U
back of the — sub index.
A
Searching
When searching for duplicates in the files, much
the same method is used as for filing.
Before starting the search, check the classification
formula so that you are certain it is correct. Note
23
the primary classification; if it is — look for a denom-
9
inator guide marked nine, or one with a number less
than nine for a left side denominator member and
more than nine for a right side denominator mem¬
ber. Open that drawer, and find a denominator guide
bearing the number 9, and continue in back of it till
a numerator guide marked 23 is reached. Suppose
M M
the sub-classification to be —-——; within the bunch
I
22 24
of cards between — and — look for some bearing a
9 9
denominator I. If there are fifty or more with this
same denominator look for an M M numerator. If
M M
there are still several cards bearing an sub-
I
classification, look at the final classification. Sup¬
posing the ridge count of the loop of the right little
finger to be 11, look for a card bearing a number 8.
Allowance of three ridges either way is always made
for the final classification or little finger ridge count.
That is, one operator may count 10 ridges and an¬
other 11 on the same print. To prevent any chance
of missing a duplicate this allowance is made. If
there are cards bearing a final classification of 8, pick
LESSON THIRTEEN
7
out some odd print in the set you have and for which
you are trying to find a duplicate.
A curious formation of a core, a lateral, or central
pocket loop, will often present some such salient
characteristic. Fix a picture of this formation in your
mind, and turn the cards in the file over slowly, look¬
ing at the corresponding digit of each card, and for
a duplicate of such characteristic formation. Con¬
tinue the search through the cards bearing final classi¬
fications 8, 9, 10, 11, 12, 13 and 14. If there is a
duplicate of the set in the files it will be found in this
last bunch.
We will conduct a theoretical search for a set of
2 rA2a
prints bearing the formula , as filed in a col-
6 tUr
lection of one half million records. In a collection of
this size, an average of three primary classifications
would be filed in each drawer. That would mean
that you would require cabinets totaling about three
2
hundred and fiftv drawers. The — primary drawer
6
32
would follow one or two drawers after the — drawer.
5
1
It would be about the fifth drawer after the —
1
1 32 1 32
section. That is, the drawers from — to —-, — to —,
1 12 2
1 32 1 32 1 32 1
— to —, — to ■—-, —- to —, and possibly — would
3 3 4 4 5 5 6
2
precede it. Open the drawer containing the — cards.
6
They will fill from one-third to all of the drawer. In
8
THE SCIENCE OF FINGER PRINTS
A
this drawer find the — sub-guide. It will follow the
U
U T
sub-guide — and will precede the guide marked —.
R U
In this sub-group look through the cards until a "t"
is found in the left thumb.
Through those cards having tented arches in the
left thumb, search for radial loops in the left middle
finger. Do this by comparing the parts of the
formula. Then pick out cards having the same num¬
erator. Through these, search carefully, comparing
individual prints on each card with those on the rec¬
ord you have, for a duplicate.
If your search has been unsuccessful, check the
formula again, so you are certain that the set could
not be differently classified.
On the finger print cards which you received with
the outfit, you will note that a space is reserved in the
upper right hand corner directly under the space
marked "F. P. Formula," which reads "Ref." This
space is to be used when a reference classification is
necessary. Occasionally you will come across some
sets which contain prints which will be hard to
classify one way or the other. That is; they will
border upon two types. Thus an arch will approxi¬
mate a loop so closely that you fear one expert might
classify it one way and another expert the other way.
With such sets, classify the doubtful prints to be of
the type you feel certain they are. Place the result¬
ing- formula in the reg-ular "F. P. Formula" space.
Under the "Ref." make out the formula classifying
the approximating- or doubtful print to be of the other
type. Where reference classifications are necessary
secure two sets of prints if possible. File one under
one of the formulas using the other as a reference.
File the second set under the formula used as a refer¬
ence on the first. The regular formula of the first is
LESSON THIRTEEN
9
used as the reference on the second set. If only one
copy of the prints is available, use a blank record for
the duplicate, marking the "F. P. Formula" and
"Ref." on it, filing it blank. This system of cross
filing or double filing will prevent the set being missed
when looking for a duplicate, by reason of it being
differently classified at a later date. Sometimes a loop
will have just nine ridges between the core and delta
in the index finger with the appearance of another
ridge, or the core or delta point is not very distinct,
or a ridge comes very close to touching the imaginary
straight line from the two termini. Another classifier
might count ten ridges and classify the print as outer,
while you called it inner. In instances like this run
a reference formula on the sub or secondary classifi¬
cation.
Suppose Ave had a set of prints bearing the formula
23 I
12. The central pocket loop of the left middle
1 O
finger, very closely approximates a plain loop and
mig'ht easily be mistaken for one by a less careful
23 I
classifier. The formula 12 will therefore have to
1 O
be referenced. Classifying the left middle finger as a
21
loop changes the primary classification to —. It also
1
makes the left index and middle fingers of the same
type, so that both must be used in the sub-classifica-
I
tion, changing- it to —. The reference formula there-
01
21 I
fore would be 12. One card would have to be
I OI
filed under each classification. In searching for a
10
THE SCIENCE OF FINGER PRINTS
duplicate of this set a double search would neces¬
sarily be made, one under each heading.
Search is made for sets of prints requiring a com¬
bination of classifications due to missing and indis¬
tinct prints, in the same way as for references, except
that the combinations are not noted on the card and
several more compartments will have to be searched
in most cases.
Examination Questions on Lesson Thirteen
1. Explain in detail how you would proceed to
search for a set of prints with the classification
12 Ra
formula 12 in an eight-drawer set containing
18 tU
about fifteen thousand records.
2. How would you g"0 about filing a set of prints
23 IM
bearing the formula 9 in a verv large collec-
9 O
tion, say half a million records?
3. What is the new extension used in the second
1
subclassification of the — section in very large collec-
1
tions ?
4. Describe the new classification extension
32
adopted for sub-classifying — cards in very large
32
collections.
5. What is the space marked "Ref." on the finger
print cards used for?
6. What arrangement of double filing is used on
cards bearing- reference classifications to prevent a
set being" missed upon subsequent search ?
7. In searching for duplicates what allowance for
error is made in the final classification for the little
finger ridge count?
8.
LESSON THIRTEEN
11
(9)(10) (16)
W \ \ CP \
/ / / W \
(6) (4)
Above is a symbol fraction representing a set of
finger prints. The numbers in parenthesis above the
right index, right middle, right little and below the
left index and left middle fingers, represents the ridge
count of the loops in those fingers.
9 Uli
Why is the formula — 6 incorrect for the
18 Uli
above symbol fraction? What is the correct formula?
9. Re-arrange the following formulas, showing
each one in the proper order of filing. That is, place
the one that would be filed back of all the rest, last.
Place the one that will be filed next to the last, be¬
fore it, etc:
1 RIO 1 U OI 1 Ut 1 U3r 1 R I O
10, 9, 6, , 9.
1 UOI 1 U 00 1 rA 1 rT 1 U O I
1 Ut 1 Ut2r
6, .
1 At IrT
10. Re-arrange the following primary classifica¬
tions in the order in which they would be filed, the
same as above. That is, the lowest first and highest
3 32 18 14 27 19 31 16 28 17 2
1 r\ of •
* y y y y y y y y y y
23 7 12 2 27 22 7 12 27 2 23
THE SCIENCE
of
FINGER PRINTS
Lesson Fourteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Fourteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON FOURTEEN
Preparing Finger Print Evidence for Court
When a latent finger print has been found at the
scene of a crime and a duplicate of it has later been
located, either in the files or from the prints taken
from a suspect's finger, it will in some cases have to
be prepared for use as evidence in court.
A 'confession can often be secured from the suspect,
however, by confronting him with the two enlarged
prints, explaining where and when they were found
and pointing the identity out to him. If he does con¬
fess you will save the cost of court expenses for your
client and will be reimbursed accordingly. Some sus¬
pects will be crafty and will obstinately refuse to
admit their guilt. Then the prints will have to be
properly prepared.
To start with you will require a photographic nega¬
tive of the latent print and one from a print taken
from the suspect's finger.
A print, natural size, is too small to convince a jury
of the identity existing between the two. The aver¬
age juror will know practically nothing about finger
prints, and in order that you be able to convince him
of the identity you must present it to him in the very
clearest, plainest and most concise manner humanly
possible.
By experience it has been found that photographic
enlargements of the prints are necessary. If you
have a photographer make the enlargements for you
he can testify as to their genuineness. It you make
them yourself, have some outsider act as a witness.
These enlargements are to be 8 inches long and 10
inches wide, the actual print itself occupying all but
two inches of margin around the paper. One of these
enlargements is of the latent print, and the other of
the print taken from the suspect's finger.
These enlarged prints must then be plainly marked,
to clearly bring out the points of identity.
4
THE SCIENCE OF FINGER PRINTS
The five characteristics or details outlined by Gal-
ton (called the Galton details) are usually used for
purposes of comparison. These five characteristics
are :
(1) The Bifurcation. A bifurcation is a
ridge which forks or splits in half, each fork
continuing as a separate ridge.
(2) Ridge Dot. T he ridge dot is a very
short segment of a ridg-e or ridge formation.
It is about as long as it is wide, appearing
in the print as a dot or period.
(3) Short Line Ridge. A short line ridge
is a slight prolongation of a ridge dot. It is
a ridge which has its source and ending
within the pattern.
(4) Abrupt Ending. An abrupt ending
is, as its name implies, a ridge which stops
suddenly, having its end inside of the pat¬
tern.
(5) An Island. A ridge which bifurcates
and again joins into a single ridge.
Figure 1 illustrates each one of these Galton de¬
tails.
1. Island
2. Bifurcation
3. Abrupt Ending
4. Short Line Ridge
5. Ridge Lot
In addition to these five points, the formation of
the core and deltas are used for purposes of com¬
parison, as is also the general type of pattern.
Several methods are used for comparing two prints.
The most common is the indication of the Galton
z
Figure 1
LESSON FOURTEEN
5
details by lines radiating from the characteristic out
into the margin around the print. The lines are num¬
bered consecutively. The same characteristics on
both prints must be marked and numbered consecu¬
tively, when comparing the two, for proving identity.
A table of explanation is then drawn up, explaining
each one of the characteristics enumerated on both
enlargements. Do not make two tables, one for each
photograph. Furthermore, this table of explanation
should be prepared on a separate sheet of paper. Do
not crowd it in on one corner of the photograph.
In marking the characteristics on an enlarged
print, be as neat as you know how. Much of the
value and weight your evidence will carry with the
court depends upon the clearness with which it is
presented. It is best to draw the characteristic lines,
first with a pencil, then when they are satisfactory,
they can be inked in over the pencil markings. DraAv
an oval around the print, very lightly in pencil, so
that it can easily be erased, leaving about one inch
of margin from the sides of the print. Extend your
radiating characteristic lines to touch the circumfer¬
ence of this circle. Then after the lines have been
inked in, the penciled oval around the print can be
removed. It is much easier to follow the consecutive
characteristics when they extend evenly around the
print than when one is way out and the next one close
to the margin of the print and a third one half way
between the other two, etc.
Another thing, do not cross any of the character¬
istic indicator lines. It is very confusing to follow
up a line when it is crossed in several places by other
lines.
On the other hand try to space them evenly. After
the print has been properly marked in pencil, ink it
in with red or black India waterproof ink. This ink
is thicker than ordinary writing ink, and is best ap¬
plied with a ruling pen, such as is used by architects.
One of these pens can be purchased for a few cents,
and it will do the work one hundred per cent better
than a common writing pen.
6
THE SCIENCE OF FINGER PRINTS
When ordering- enlargements, or if you make them
yourself, use a paper with a semi-matte surface. This
surface will take the ink much better than a glossy
surface.
Figure 2 shows three impressions from the same
fing-er, marked in this way. The impression in the
upper left portion was made with ink from the sus¬
pect's finger. The impression to the right is a copy
of one left on the front door by the perpetrator of
the robbery, as is also the one in the lower left-hand
corner. This print was left on the arm of a chair.
The characteristics enumerated in these prints are
explained in the table "D" of Figure 2.
The data on this case is as follows:
United States v. August Meier, alias Henry Vandal.
On March 3, 1918, the store of Louis Sonnebaum at 495 Penn¬
sylvania Avenue N. W., Washington, D. C., was entered by a
burglar and a lot of clothing stolen.
Upon examination of the premises it was found that the bur¬
glar entered the place through a transom over the front door and
left by the same route. In order to reach the transom from within
he carried an arm chair from the rear of the store and placed it
against the door. Several finger prints were found on the arm
of the chair, one in which the details were clear was photographed,
also one found on the inner surface of the glass in the front door.
A lookout for the clothing was sent to nearby cities and a few
days later a man giving the name of August Meier alias Henry
Vandal was arrested in Baltimore, Md., while trying to dispose
of some clothing, stolen. Meier was brought to Washington on
the 11th of March; he denied having entered the store, claiming
that he bought the clothes from a stranger, but when his finger
prints were taken it was found that the print from the left thumb
was identical with those found on the chair and door.
Meier waived examination in police court and was held for
the action of the grand jury. On April 1st he was indicted for
housebreaking. On April 5th arraigned in Criminal Court No. 1,
Judge Wendell P. .Stafford presiding. He pleaded not guilty and
was tried by jury. After Government had presented its case, the
attorney for Meier offered no defense, the finger print evidence
placing Meier in the store, and Judge Stafford instructed the jury
to bring in a verdict of guilty as indicted.
On June 8, 1918, Meier was sentenced to serve six months in
the United States penitentiary at Atlanta, Ga.
When explaining- these characteristics to the jury,
have them compare each print on both impressions,
LESSON FOURTEEN
7
fihqtr prinfyfrjd 'i
^cn1 arm of choir
3) i.
Bifurcation
2.
Bifurcation
jjk C 3.
Bifurcation
4.
Bifurcation
5.
Abrupt Bnding
6.
Abrupt Ending
ft 7.
y it
Ridge Dot
-—II 8.
Short Line Ridge
9.
Abrupt Ending
10.
Bifurcation
XL.
Abrupt Ending
12.
Abrupt Ending
13.
Bifurcation
Figure 2
and be sure they understand each point brought out.
It sometimes helps to make the explanation more
graphic by making a sketch of the part of the impres¬
sion containing the characteristics to one side of your
enlargement, and about the same size. Such a sketch
8
THE SCIENCE OF FINGER PRINTS
can very easily and accurately be made by using a
pantagraph. These pantagraphs can be had from any
artists' or architects' supply house.
The use of a stereopticon lantern, throwing the
image on a screen in very large size, has been success¬
fully practiced. The identity of the prints becomes
very apparent on this large sized view. The expert
can point out the characteristics on the screen in the
same way as on the enlargements.
Bring all the evidence you have with you to court.
If at all possible, bring the developed latent finger
print itself, as it appeared on the surface where it was
found. If this is impossible, have a photographic
print of it showing it in natural size. Then have a
print taken from the suspect's finger in ink.
Several copies should be struck off from the en¬
larged exhibit, bearing the marked characteristics
and a table of explanation of these characteristics.
Each one of the jurors should be supplied with a copy.
The judge and attorneys should also each possess a
copy.
In some states it is not permissable to make any
marks on photographs used as evidence. And the
attorney for the defense will often bring this up as
a legal point. It is advisable that you secure a copy
of the Laws of Evidence as applicable to the courts
of your city and state, and familiarize yourself with
them.
When you are called on the witness stand you will
have to qualify as a finger print expert. Your train¬
ing, past experience, and general knowledge will be
the main factors bearing on the qualification. You
will in nearly every case be required to relate the his¬
tory and evolution of finger printing, explain the
chances of two being alike, and the persistency of the
pattern. Familiarize yourself especially with these
points by the restudying the texts bearing on these
subjects (lessons 1 and 2) until you have them well
fixed in mind.
LESSON FOURTEEN
9
When cross-examined by the attorney for the de¬
fense, be extremely careful in answering. Be very
conservative in your statements, and always think
twice before you answer. Never make a statement
which you are not positive is absolutely correct.
Lawyers, as a rule, are very clever in getting expert
witnesses confused, and once you allow yourself to
make a wild statement and later contradict it, the
value of your evidence, no matter how strong, will
slump to a very great extent in the eyes of the jury,
and your reputation will be badly marred. There¬
fore have your case well in hand before taking the
witness stand.
In important cases the opposition will often hire
a finger print expert to examine and pass his opinion
on your evidence. You will therefore have to be
doubly sure of yourself.
One thing I wish to impress on you again, very
strongly, is that you must mark the characteristics
on the enlargement. Never mark them on the small
print and have them photographically reproduced on
the enlargement. The reason is obvious. The orig¬
inal sized print is very small, and a common inked
line will be as thick or thicker than the ridges. Any
inaccuracy on this small print will show very badly
on the enlargement.
When you have the prints enlarged have them
mounted on a large sheet of white paper, or better
still, have plenty of margin left around the print
itself on the photographic paper so that you will have
plenty or room in which to indicate the characteris¬
tic without in any way crowding your work.
Your two marked enlargements, the pantograph
sketch and table of explanation, should be neatly ar¬
ranged and mounted on a large sheet of paper.
10
THE SCIENCE OF FINGER PRINTS
Examination on Lesson Fourteen
Make a latent finger print impression on some
smooth surface with your finger. Develop it care¬
fully with a powder in strong contrast to the surface
on which you made the print. Then make a nice
clear rolled print from your same finger on a piece
of smooth white paper. Have a photographer make
two 8xl0-inch enlargements of the prints. Prepare
these enlargements just exactly the same as if you
intended to present them in court as evidence. Send
them to the school for correction.
Note: You will be graded according to the quality
and neatness of your work.
THE SCIENCE
of
FINGER PRINTS
Lesson Fifteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Lesson Fifteen
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
LESSON FIFTEEN
Operation and Maintenance of a Finger Print
Bureau
You have now learned all about the science of fin¬
ger prints. Every phase of the work has been thor¬
oughly covered in the preceding lessons. In this final
lesson we will discuss the operation and maintenance
of the average finger print bureau. There are, of
course, two general classes of bureaus, the criminal
identification, and the private, or commercial bureau.
Each has its own specific functions.
In case of a criminal bureau, it will be operated in
connection with a police department, penal institu¬
tion, or detective agency. In case it is a g-overnment
institution, its size and functions will be entirely de¬
pendent upon the government, local, state or federal.
All appropriations for its operation and maintenance
will be made by the government, and its functional
limits will be determined by the government.
The police bureau will have to do the recording of
all suspects and notorious criminals at large, and the
prison bureau of its inmates.
We will first consider the police bureau. Every
morning the suspects who have been picked up for
the past twenty-four hours will be brought in for
registration. In a small local bureau, two sets of
impressions will usually be taken. The subject's
name, address, offense, etc., will be noted on each
card or set.
The local file will first be searched for a duplicate
of the set. The other card is forwarded to the central
bureau at Leavenworth, Kansas, for identification.
If no duplicate of the card is found in the local file,
it will be given a number to correspond with a blank
page of a ledger. In this ledger is written all the data
concerning the case. A small index card is also made
out, one under each name, and alias, of the prisoner.
On this card is noted the classification formula of his
4
THE SCIENCE OF FINGER PRINTS
finger prints and the ledger number. These index
cards are filed alphabetically in a small drawer file.
The finger print card is then filed according to the
classification formula. AVhen word is received from
the central bureau at Leavenworth, any new informa¬
tion is noted in the ledger. If no identification has
been made at the central bureau either, the source is
notified to that effect. If the prisoner is going to be
tried for some offense, the presiding judge should be
furnished with all the facts at your disposal, concern¬
ing the subject.
The operation of a prison bureau is the same as
that of a police department.
The central finger print bureau at the federal peni¬
tentiary at Leavenworth, where Mr. A. J. Renoe is in
charge, is operated solely to act as a clearing house
for finger prints for all other penal bureaus in the
country. This bureau is supplied every day with the
finger print records of suspects and criminals appre¬
hended all over the country. The use of this bureau
is extended, without charge, to all who have legiti¬
mate use for it; in fact, all are urged to co-operate
with the central bureau and make use of its records.
This central bureau will furnish you, free of charge,
with their style of fing'er print blanks. All records
sent to the bureau should be made on these long rec¬
ord cards, as the open shelf system is used at that
bureau. You will not need to classify the records you
send there.
The bureau at Leavenworth is composed of four
divisions, or departments. The classification, the
checking, the searching and the clerical departments
make up the four. All incoming mail is first sent to
the clerical department, and is opened and sorted.
All the finger print records are turned over to the
classification department. This department works
out the formula for each set of prints received and
then turns them over to the checking department.
LESSON FIFTEEN
S
The checkers verify the correctness of the formula,
and examine the set to see that each print is in its
proper space. When checked, the cards go to the
searchers, who are in charge of the files.
The searchers look through the files for duplicates
of the sets. If a duplicate record is found, it is
fastened to the original and returned to the clerical
force. If no duplicate is found the record is returned
to the clerk marked "no record." The clerks notify
the source by letter as to what information they have.
On all records of which duplicates were found new
information is noted on the back of the original cards.
Then all records, both identified and non-identified,
are returned to the filing department for filing. All
the originals are returned to their respective places
in the files. All duplicates are kept separately, bound
in loose leaf books, or destroyed. Each man special¬
izes on a certain branch of the work in this bureau
and becomes expert in it. The efficiency of the entire
bureau is in this way brought to the highest point.
Private and industrial bureaus will have to be oper¬
ated to suit the individual purpose which they are to
serve. Prints should be taken of all ten fingers and
filed in the regular way. If the bureau is to be oper¬
ated for a large concern, in checking up on their em¬
ployes, each employe's prints should be taken upon
his acceptance for employment. A set of his prints
should be sent to the central bureau to find out
whether he has had any past police record. One set
should be filed according to the formula. On the
back of the card space can be left for signature, ad¬
dress, telephone number, nearest relative, and name
and address of such relative, date employed, age,
nationality, etc.
If the system is to be used in connection with the
pay roll, take an impression of each employe's thumb
and have him sign his name at the top of the card.
File these alphabetically, according to names. When
an employe calls for his pay, take an impression of
6
THE SCIENCE OF FINGER PRINTS
his thumb, together with his name, and compare it
with the one you have on file. In this way it will pre¬
vent the drawing of an employe's pay by someone not
entitled to it. Where more than two hundred people
are employed, a paymaster cannot remember each
individual person and in such cases the finger print
system will prove an infallible method of identifica¬
tion.
The system is installed in banks for the use of
illiterate depositors and for persons drawing large
sums of money, to prevent fraud. No standard sys¬
tem of filing has been adopted. This field is open
to the ingenuity of the expert.
The finger print expert can also maintain a private
bureau of his own. Your prospective clients will be
men who are well off financially, children of wealthy
parents, traveling men, etc., for purposes of individual
registration, and commercial concerns for registra¬
tion of employes ; also in assisting detective agencies
and other investigating bureaus. The ten finger
Henry system will be found most satisfactory in
every place. This, of course, is the system which you
have learned in this course of lessons.
Relative to the fees you should charge in operating a
private bureau: this work is like that of the law, medi¬
cine or any other profession, and the charges should
be made commensurate with your client's resources.
For individual registration, $1.50 to $50 a year is not
at all excessive. For registering employe's prints,
make a regular yearly charge, depending upon the
number of employes. About $1.50 each for less than
500, and $1 each for any amount over 500 is reason¬
able and will net you good profits. Whenever you
testify in court for a client, a charge of $25 a day with
all expenses paid for all the time so spent is a very
reasonable amount.
When operating a bureau of any kind, and espe¬
cially a private one, it should be as neatly arranged
and as well appointed as possible.
LESSON FIFTEEN
7
Use the vertical drawer filing system. An eight-
drawer cabinet will be large enough to start with.
You can purchase all of your finger print filing equip¬
ment from the Yawman & Erbe Company of Roches¬
ter, N. Y., who make a specialty of finger print equip¬
ment. The filing cabinet should be placed in your
office so that the light strikes the front of it.
The recording table should be placed directly under
a window, so that it will be well illuminated during
the day. An artificial light should be suspended over
it to furnish illumination when daylight is not suffi¬
cient. The classifying desk should be especially well
illuminated. Classifying finger prints is strenuous
on the eyes, so arrange to have plenty of light on this
desk. Place a strong electric light over it for night
work and use a green shade over your eyes. By the
side of your recording table have your washing stand.
If possible provide warm water. Have a container
of benzine handy and some absorbent cotton for re¬
moving the excess ink from a subject's fingers. Pro¬
vide Ivory soap and individual tissue-paper towels.
Have your subject wash his hands thoroughly before
taking the prints of his fingers, and immediately after
washing swab each finger with alcohol to close the
pores and prevent accumulation of sweat on the
ridges. The remainder of your bureau can be ar¬
ranged to suit your own tastes. A dark room, photo¬
graphic and chemical units can be provided for.
Arrange with the United States Department of
Justice at Leavenworth by letter so that you will re¬
ceive all of their reward circulars. The department
will be gdad to issue these to you without charge.
Most of these will contain finger print reproductions
and fing'er print formulae. File all such reward cir¬
culars in your finger print file. If the circulars are
too large the way they are issued, cut them up and
paste the important parts on one of your blank finger
print cards. In this way you can make a regular
album of rewards for ready reference. You will have
8
THE SCIENCE OF FINGER PRINTS
a good chance of picking up large amounts of reward
money in this way.
You might find it profitable to advertise your
bureau in the local papers. Daily newspapers, house
organs, and especially financial publications are good
mediums. A small classified or display ad should
bring good results. Have interested prospects ar¬
range with you by telephone for an interview. You
then have a good opportunity to make your sale. I
would not advise spending too much money on adver¬
tising, however, as this is a proposition best sold by
personal solicitation. Make up a list of every person
or concern in the vicinity which you think will have
some use for the system. Get up a good sales talk
and interview each one of these prospects, pointing-
out the advantages the system would be to their
special organization.
You have now covered the entire field of finger
print work, and upon completing the final examina¬
tion, we are sure that you will be able to successfully
hold down any kind of a finger print job.
Examination Questions on Lesson Fifteen
General Review
1. What is a finger print?
2. How long- does the pattern on the human finger
persist ?
3. What is the standard system of classification
called ?
4. How are finger prints made on record cards for
filing? Explain process in detail.
5. What is a latent finger print?
6. How are latent finger prints developed?
7. What is the primary classification?
8. How are records filed by the primary classifica¬
tion ?
LESSON FIFTEEN
9
aA2a
9. What is a part of a formula reading
tR2r
called ?
10. What kind of a sub-classification results when
whorls appear in the indexes?
11. How many primary classification combinations
are possible under the Henry system?
12. What are the essentials of a camera capable of
photographing finger print impressions?
13. How is a latent print found on paper developed
chemically?
14. On what side of your subject do you stand
when taking his right hand prints? His left hand
prints?
15. In what direction do you roll the right hand
fingers when taking' prints of them? The left hand
fing'ers ?
16. What instructions should you issue to the
police officers when notified that a crime has been
committed ?
17. According to Galton, what are the chances of
two finger prints being alike?
18. Work out the primary classification for the fol¬
lowing letter symbol fraction (assume that the set is
to be filed for the first time) :
A W \ \ Amp.
W A / CP Amp.
19. Work out the sub-classification for the fol¬
lowing letter symbol fraction:
A \\ T \
/ / / CP /
20. What are the standard symbols used?
THE SCIENCE
of
FINGER PRINTS
Final Examination
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
THE SCIENCE
of
FINGER PRINTS
Final Examination
Dunlap School of Finger Prints
1029 South Wabash Avenue
Chicago, Illinois
U. S. A.
Copyright 1921
by the
Dunlap School of Finger Prints
Final Examination
The student is required to have made a grade of at
least eighty per cent on every examination of the
fifteen lessons composing the course of instruction in
the finger print science as prepared by this school,
before being permitted to take this final examination.
The faculty and directors of the Dunlap School of
Finger Prints have made this examination practical
in every way. It has been compiled in such manner
that the student may refer to the lesson texts or to
any other treatise on finger print identification as
often as is desired while writing out the answers.
Do not begin this examination before you have
thoroughly reviewed the entire course. In review¬
ing, concentrate especially on all the lessons treating
the subject of classification. Your answers to the
last forty questions will depend upon how well you
know this subject.
This test consists of fifty questions. The first ten
deal with finger print identification in general, cover¬
ing every practical phase of the work. The last forty
questions are each a ten finger set of prints. You
are required to work out the complete classification
formula for the filing of each set. On the regular
examination paper preferably, or the paper you are
using, write the number of the set or question in the
margin. Directly opposite the number write, or bet¬
ter still print plainly, the complete formula. You do
not need to show the work necessary to obtain the
results ; the answer is all you want to see. Where you
think it is absolutely necessary, run reference form¬
ulas on the classification. On your final classifica¬
tions you will be allowed a variation of six ridges,
that is, three ridges under or three ridges above the
correct count of the little fing-ers. ABOVE ALL.
ADHERE WITHOUT THE SLIGHTEST VARI¬
ATION TO THE STANDARD HENRY SYSTEM
OF CLASSIFICATION AS TAUGHT IN OUR
LESSONS. EVERY CLASSIFICATION MUST
BE WRITTEN IN STANDARD FORMULA
FORM.
4
THE SCIENCE OF FINGER PRINTS
You will notice that the patterns reproduced in this
examination are a trifle smaller than natural size.
This should not cause you any trouble, as by using the
magnifying g'lass each print can be easily read. A
few of the patterns are a bit indistinct. None of them
are so indistinct, however, but that a little effort will
enable you to correctly classify them. You may be
assured that when you are actually engaged in the
finger print profession you will be required to classify
finger print patterns which are a great deal harder to
read than any in these questions.
Use pen and ink or a typewriter in writing out your
answers. We will not accept papers written with pen¬
cils. Use a smooth surfaced white paper, preferably
the regulation school blanks and WRITE ON ONË
SIDE OF THE PAPER ONLY.
You will be given a credit of 2 per cent for each
correct answer out of the fifty. Eighty per cent is
the passing grade. Correct answers will be checked
in the usual manner; a cross indicates that the answer
is wrong. No explanations will be offered or any
corrections made on questions answered incorrectly.
If you should fail to make the required grade of 80
per cent you must wait six weeks before being per¬
mitted to try again. Under no circumstances can you
take this examination a third time before writing the
instructor stating that you have reviewed the entire
course and have studied consistently for the six weeks
immediately preceding, and feel confident that you
will be able to make good.
Figure 1
FINAL EXAMINATION
5
EXAMINATION QUESTIONS
Questions No. 1 to 5—The five finger print impressions illus¬
trated in Figure 1 correspond to, or are identical with some one
print in the forty sets which make up the last part of this examina¬
tion. On your examination paper, indicate by question number
with which set and finger each of these prints correspond. (Exam-
Print number one corresponds with the left ring finger print
y *he set of Question 28.)
Question No. 6—Work out all the possible combinations for an
exhaustive search of the files for the set of prints illustrated below,
Fig. 2, supposing the missing fingers to have been present when
the first set was taken and filed.
F. P. No_
Dept.
.LEDGER No_
F. P. FORMULA
REF.
RIGHT HAND
1. RIGHT THUM8
2. R. FORE FINGER
3. R. MIDDLE FINGER
L R. RING FINGER
5. R. LITTLE FINGER
<?■
LEFT HAND
6, LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
Figure 2
Question No. 7—Lift a developed latent finger print from some
Ç Jid object with a gelatine transfer and send it in with the re¬
mainder of your examination. You will be graded on the quality
of the work.
Question No. 8—You will find a sketch on the last page of this
book which represents a 24-drawer filing cabinet. Each drawer is
numbered. You must mark the guides on the outside of each
drawer, indicating the first and last primary classifications which
are to be contained therein. Tear this sheet out and send it in with
the rest of your examination.
Question No. 9—On your examination paper indicate by drawer
number, of the file represented by the sketch of Question eight
THE SCIENCE OF FINGER PRINTS
which you have filled out, where each of the following primary
7 31 5 4 27
classifications would be contained —. —. —, —, —. (Example:
26 32 19 26 2
7
The primary classification — would be contained in drawer num-
26
ber 22.)
(
F. P. No_
Dept.
—LEDGER No_
J
F. P. FORMULA
REF
RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
mm
i '
Kj SU JÜ
■ M&ÊUjk
LEFT HAND
E. LEFT THUMB
7. L FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
LEFT HAND
RIGHT HAND
PLAIN IMPRESSIONS OF THE FOUR FINGERS TAKEN SIMULTANEOUSLY
PLAIN IMPRESSIONS OF THE FOUR FINGERS TAKEN SIMULTANEOUSLY
•Ml
aiyw
m
1ÉÂ
1»*. M
o
NAME OF EXPERT
ADDRESS
CITY
_LESSON No._
DUNLAP SCHOOL OF
FINGER PRINTS
chicago
Figure 3
(Catch question.)
Question No. 10—Work out the complete classification formula
for the set of prints illustrated above, Fig. 3. Be very careful in
working out this formula as there is a catch in it. (Hint: Study
lesson four again before answering it.)
FINAL EXAMINATION
7
RIGHT HAND
1. BIGHT THUMB
2. B. FOBE FINGES
3. B. MIDDLE FINGEB
4. B. BING FINGEB
5. B. LITTLE FINGEB
ÍÜ1
«■Ii ■
ÍIIHBI
LEFT HAND
6. LEFT THUMB
7. G FOBE FINGEB
B. G MIDDLE FINGEB
9. L BING FINGEB
10. L. LITTLE FINGEB
■
s
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jpn
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ill
RIGHT HAND /-?
1. BIGHT THUMB
2. B. FOBE FINGEB
3. B. MIDDLE FINGEB
4. B. BING FINGEB
5. B. LITTLE FINGER
cf
9%
«S
ggl
LEFT HAND
6. LEFT THUMB
7. G FORE FINGER
8. G MIDDLE FINGER
9. G RING FINGER
10. G LITTLE FINGER
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8
THE SCIENCE OF FINGER PRINTS
1. BIGHT THUMB
2. B. FORE FINGER
RIGHT HAND
3. R. MIODLE FINGER
4. R. RING FINGER
TT
5. R. LITTLE FINGER
LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIODLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
fl
^ >v
m
-f»
IT
RIGHT HAND
I. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDCLE FINGER
I. R. RING FINGER
5. R. LITTLE FINGER
LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
■■
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RIGHT HAND
RIGHT THUMB
»
2. R- FORE FINGER
'
3. R. MIDDLE FINGER
I. R. RING FINGER
&
5. R. LITTLE FINGER
ÍT8
LEFT HAND
FINAL EXAMINATION
9
10
THE SCIENCE OF FINGER PRINTS
27
1. RIGHT THUMB
2. R FORE FINGER
3. R MlDCLE FINGER
4. Ti. RING FINGER
3. R. LITTLE FINGER
uu
•
Ip «Efe
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1. RIGHT THUMB
2. R. FORE FINGER
3. R MIDDLE FINGER
4. R RING FINGER
5. R. LITTLE FINGER
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LfcFT HANI;
6. 1ER THUMB j 7. * L FORE FINGER | 6. L MIDDLE FINGER j 9. L. RING FINGER | 10 L. LITTLE FINGER
FINAL EXAMINATION
11
RIGHT HAND Z§3
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
■IB
0
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m
I
LEFT HAND
i 6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L RING FINGER
10. L. UTTLE FINGER
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RIGHT HAND
1.- RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
6. R. UTTLE FINGER
3
P3ï
m
LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FiNGER
10. L. LITTLE FINGER
ljf- ^
¡¡Mil
RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
6. R. LITTLE FINGER
;,lf§i
r \Wmm>
m
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LEFT HAND
B. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. UTTLE FINGER
Éjj
IS
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'^S§dii§8í
12
THE SCIENCE OF FINGER PRINTS
RIGHT HAND J?&
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. ,R. LITTLE FINGER
S
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J|SÄ
P
LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. UTTLE FINGER # >
ÊÊÊÊ
g j*%ái§r
S
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RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
6. R. LITTLE FINGER
V5
9HI
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MÊÊt
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LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
S. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
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Werner
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1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
6. R. LITTLE FINGER
Í31
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*****
FINAL EXAMINATION
13
kk.iii hand
2?
1. right thumb
2. r- fore finger
3. r. miqcle finger
4. r ring finger
5. r. little finger
ifevffr V: '
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fifpt
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left hand
! 1 6. left thumb
1 l. fore finger .
8. l. middle fincer
1. l. ring finger
10 l. little finger
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life
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right hand
30
1. right thumb
2 r fore finger
}. r miodie finger
4. r ring fincer
5. r. little finger
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left hand
6. left thumb
7 l fore finger
8. l. miodle finger
9 l ring finger
10 t little finger
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rigid hand
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1 right thumb
? r fore finger
3 r mioole finger
4 p king finger
i r little finger
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6. left thumb
' l fore finger
8 l miodle finger
9 i rinc finger
jû l. little finger
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11
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14 THE SCIENCE OF FINGER PRINTS
RIGHT HANI)
32
• 1 RIGHT THUMB
2. R FORE FINGER
3. R. MIODLE FINGER
4. R. RING FINGER
5. R LITTLE FINGER
1
m
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left hand
6. LEFT THUMB
7. L. FORE FINGER
8. L MlpDLE FINGER
9. L. RING FINGER
10. L LITTlE FINGERI
^ >
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RIGHT HAND
33
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
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Ignite;
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LEFT HAND
6. LEFT THUMB-
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
g
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RIGHT HAND
34
t. RIGHT THUMB
2. R. FORE FINGER
3. R. MIODLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
gjf
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LEFT HAND
6. LEFT THUMB,
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
1
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."3525^
FINAL EXAMINATION IS
RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIOCLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
\
n,
JÛ
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LEFT HAND
»6. LEFT THUMB
7. G FORE FINGER
8. G MIOOLE FINGER
9. G RING FINGER
10. L. UTTLE FINGER
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RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINCER
4. R. RING FINGER
ó. R. LITTLE FINGER
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LEFT HAND
6. LEFT THUMB
7. G FORE FINGER
8. G MIDDLE FINGER
9. G RING FINGER
10. G LITTLE FINGER
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RIGHT HAND
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LEFT HAND
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16
THE SCIENCE OF FINGER PRINTS
RIGHT HAND
38
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
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fill
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LEFT HAND
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6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGEf^
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fill
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RIGHT HAND
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
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LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
1 9. L. RING FINGER
10. L. LITTLE FINGER
M
¿mÙÊÈÈk
fi
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RIGHT HAND
4Û
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIDDLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
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LEFT HAND
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
A
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0030
FINAL EXAMINATION
17
RH.Ill HANI)
-v . „
41
1. bight thumb
2. b. fore finceb
3. r. middle finger
i. b bing finger
i. r. little finger
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^ 8. lett thumb
1 i fore finger
s. l middle finger
9 L RING FiNGER
10 l little finger
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RH,111 HAND
42
1. bight thumb
2 b fore finger
3 b m'Oole finger
» R RING FlNCEB
5 r little Finger
;
IS
i
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6. left thumb
? 1 fore finger
8. L MIDDLE FlNCER
9 L RING FiNGER
10. l little finger
ä
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RlOlll HAND
4:1
1 bight thumb
2 r fore finger
3 b m'cole finger
a p Ring Finger
i r little Finger
'*|||i'" littrnr
i ■'. i
LfcFT HAND
6. left thumb
7 1 fore finger
s. l middle finger
9 l Ring finger
10 l little finger
Sffaöa»--
iâpÉte
-
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T'rifáis
■iß,
-'^ÊÊk
18
THE SCIENCE OF FINGER PRINTS
LUFT IIAM)
6. LEFT THUMB
L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RINC FINGER
10. L. LITTLE FINGER
FINAL EXAMINATION
19
RIGHT HANI)
48
I. RIGHT THUMB
2. R. FORE FINGER
3. R. MIOOLE FINGER
4. R. RING FINCER
5. R. LITTLE FINGER
iíl'-: ' ÏÂÂÂl
m&m
. ***
fpltj
JÄ
LEFT HANI)
6. LEFT THUMB
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
■ llplí'
la
—
right hand
■¿y
1. RIGHT THUMB
2. R. FORE FINGER
3. R. MIOOLE FINGER
4. R. RING FINGER
5. R. LITTLE FINGER
S
"lÄ^SS#
¿aS
jj|
left ham)
7. L. FORE FINGER
8. L. MIDDLE FINGER
9. L. RING FINGER
10. L. LITTLE FINGER
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8
20
THE SCIENCE OF FINGER PRINTS
1. RIGHT THUMB
2. R. FORE FINGER
RIGHT HAND
3. R. MIDDLE FINGER
4. R. RING FINGER
t-m
5. R. LITTLE FINGER
■
LEFT HAND
6. LEFT THUMB
mam
7. U FORE FINGER 8. L. MIDDLE FINGER 9. L. RING FINGER
10. L. LITTLE FINGERE
FINAL EXAMINATION
21
/
7
7 3
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z
8
H
20
3
9
IS
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+
to
16
22
S
II
17
23
6
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18
24
Above sketch represents a 24 drawer finger print filing cabinet.
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