The Red Thumb Mark

icroscope of the pattern used for examining plate-cultures of micro-organisms, on the wide stage of which was one of the cards bearing six thumb-prints in blood. A condenser thr

rked as, in response to a double ring of the electric

ed the campaign, supported, as usual, b

ng seemed oddly out of character with the tea-tray that he carried, smiled

a beautiful negative washing upstairs and a bromide enlargement too, whi

ture to be a professor of physics. As an actual fact he was first a watchmaker, then a maker of optical instruments, and now he is mechanical factotum to a

ou pick him

deserved misfortune. I gave him one or two little jobs, and when I found what class of man he was I took him per

ographs he was ref

thumb-prints on bromide paper and a negative of

t imagine how you propose to go to work. To me his case seems as hopeless a one as it is possibl

I make it a rule, in all cases, to proceed on the strictly classical lines of inductive inquiry-collect facts

ceivable hypotheses: (1) that the robbery was committed by Reuben Hornby; (2) that it was committed by Walter

gard for the present and confine myself

. Hornby could have stolen the diamo

Thorndyke. "I merely state the hypotheses. John Hornby had acce

was responsible

proving. You see, he was what is called a gratuitous bailee, and in such a case no

fellow!" I exclaimed. "How ca

kind of magical touchstone, a final proof, beyond which inquiry need not go. Now, this is an entire mistake. A finger-print is merely a fact-a very import

you propose

haracter with that of Reuben Hornby-of which, however, I have very little doub

d t

ou for assistance, and, if we have finished breakf

g from the office four small, paper-covered

ter it in this book." He wrote on the cover "Reuben Hornby" and passed the book to me. "In this second book you will, in like manner, enter anything that you can learn about Walter Hornby, and, in the third book, da

rints, in which all the minute details, such as the orifices of the sweat glands and trifling irregularities in the ridges, which, in the original, could be seen only with the aid of a lens, were plainly

quare twelfths of an inch. The magnification is eight diameters, so that the squares are here each two-thirds of an inch in diameter. I have a number of these micrometers of different sc

power eye-piece. Everything is in the case; and I have put 'special

otland Yard lions in their den," said T

scope to Scotland Yard, when you only want eight diameters. Haven

ut I may have need of a more powerful instrument-and here let me give you a word of warning: whatever you may

on the inner door-the outer oak being op

table. He strode across to the door and opened it somewhat brusquely, but immed

have written to ask for an appointment but the matter is rather urgent-it concerns

etting out for Scotland Yard on this very business. Let me pr

remarked with perfect self-possession, "My name is Gibson-Miss Juliet Gibson.

Thorndyke placed for her, and continu

em. I first came to the house as a sort of companion to Mrs. Hornby, though, as I was only fifteen at the time, I need hardly say that my duties were not ve

ed daughter. Naturally, I have seen a great deal of their nephews, who spend a good part of their time at the house, and I need not tell you that the horrible charge against Reuben has fallen upon us like a thunderbolt. Now, what

ay?" asked

ss Gibson. "I understand that legal advice a

quite correctly infor

ant you to promise me that nothing shall be left undone that might help to prove his innocence if I make myself responsible

se of your generosity you would have to approach Mr. Reuben's solicitor through the medium of your guardian, Mr. Hornby, and with the consent of the accused. But I do not suppose the occasio

impertinent that you considered ne

ure to inquire if any special relati

tle. "No, there have been no tender passages between Reuben and me. We are merely old and inti

t you are engage

him-he has asked me, in fact, more than once; and I r

hing asserted were curious and rather incredible, and the tone

e he has.

atch for a young man like Walter, who has neither property nor expectations, and one naturally takes that into accou

Thorndyke, with a smile, "even if Mr. Walter were qui

hed very prettil

d to Walter Hornby, I should be sorry to apply the term 'mercenary' to him, and yet-well, I have never met a young ma

rstand that yo

friendly, but not of such a nature as

oment to Mr. Reuben. You ha

imately for six years

of character do

ed. As to theft, it is merely ridiculous. His habits have always been inexpensive and frugal, he is unambitious to a fault, and in respect

you will help us if you can, and that you can help us if you will, with your clear head and your admirable frankness. If you wil

reamily into the fire. Then, with a quick glance at his watch, he resumed his hat

as we descended the stairs; "but

not," I answe

as you could desire-what would be called in the jargon of the novels,

ibson's relations with

dyke

oncern of ou

n of ours at this preliminary stage. We are groping ab

e is not wildly infatuated wit

ly; "we may take it that the canny Wa

Miss Gibson's hand, I think I would soone

with you," said

acter was tempered by something that she had heard from a third party. That expression of hers, 'speaking from my

or in you-the capacity to perceive the essential underneath the obvious. Yes; somebody has been saying something about our client, and the thing that w

you ask her what she m

my face. "Why didn'

appear too discerning. Let me carry the microsco

case to me and rubbing his fi

. "A common pocket lens would do all that you require. Besides, a s

four. Polton made them both for me for examining cheques, bank-notes and other large objects. But

and were passing up the narrow thoroughfare, when we encount

g, doctor," said he genially. "I heard this morn

"I am going to see what ca

given us a good many surprises, but you'll give us a bigger one if yo

is no such thing. You mean that there i

ied your teeth on-and they're pretty strong teeth too, I'll say that. You had better come into Mr. Singleton's office," and he conducte

and holding out his hand. "I can guess what you

oduced me, he continued: "We were partners in the last g

eton; "and we are going

m block, and bore the pencilled inscription: "Handed in by Reuben at 7.3 p.m., 9.3.01. J. H." At one end was a dark, glossy blood-stain, made by the falling of a good-sized drop, and

ing the thumb-print and the smears in turn, but making no remark, wh

entifying that mark," the

cellent impression and a very distin

car makes it absolutely conclusive. Y

lap-pocket the enlarged photograph, at the sight of

gement; three diameters is ample for studying the ridge-patterns. I see you have divided it up into numbered squ

in length. The print was marked by a number of figures written minutely with a fine-pointed pen, each figure being

points which are important for comparison, whereas your squares or the intersections of the lines fall arbitrarily on important or unimportant point

let me take a photograph

I know you don't care to take anything on trust. And now I must get on with my work, i

inal," added Thorndyke, with a smile

as Mr. Singleton returned to his table, Thorndyke unlo

the microscope?" exclaimed Mr. Single

Thorndyke, as he set up the microscope and screwed

o the inspector, as he took the paper from Mr. Singl

did watch, with close attention and great interest, while Thorndyke

ns carefully, and then moved the thumb-print into the field of vision. After looking at this for some time with deep attention, he drew from the case a tiny spirit lamp which was evidently filled with an alcoholic solution of some sodium salt, for when he lit it I recognised the chara

erved him hurriedly draw one or two diagrams in his notebook. Then he replaced the spectroscope and lamp in the case and brought forth the microm

h that of the lines on the large photograph, which he held in his hand. After a considerabl

re on our print, so, with Inspector Johnson's assistance, we

e on its stand into a horizontal position, he produced from the camera case a slab of mahogany with three brass

e eye-piece end of the microscope was now passed, the sleeve being secured round the barrel of

mb-print by means of a condenser, Thorndyke proceeded to focus the image on the ground-glass screen with extreme

e the exposure," he said to me and the inspector. "A very litt

then removed the cap, standing motionless, wa

hould not turn out quite perfect," he said, a

same way, and then, having removed the micrometer and repl

e drew out the second dark slide. "I think I w

sures-one of the larger blood-sta

"box of tricks." "I think we have all the data that we can squeeze out of Scotland Yard, and I am very much ob

We work for a conviction, of course, but we don't throw obsta

official by the hand. "Haven't I benefited by your help a sc

u luck, though I fear you wi

ndly wave of the hand to the inspector he caught u