The Red Thumb Mark | Page 9

in-patient at the hospital when I first met him, miserably ill
and broken, a victim of poverty and undeserved misfortune. I gave him
one or two little jobs, and when I found what class of man he was I
took him permanently into my service. He is perfectly devoted to me,
and his gratitude is as boundless as it is uncalled for."
"What are the photographs he was referring to?" I asked.
"He is making an enlarged facsimile of one of the thumb-prints on
bromide paper and a negative of the same size in case we want the print
repeated."
"You evidently have some expectation of being able to help poor
Hornby," said I, "though I cannot imagine how you propose to go to
work. To me his case seems as hopeless a one as it is possible to
conceive. One doesn't like to condemn him, but yet his innocence
seems almost unthinkable."
"It does certainly look like a hopeless case," Thorndyke agreed, "and I
see no way out of it at present. But I make it a rule, in all cases, to

proceed on the strictly classical lines of inductive inquiry--collect facts,
make hypotheses, test them and seek for verification. And I always
endeavour to keep a perfectly open mind.
"Now, in the present case, assuming, as we must, that the robbery has
actually taken place, there are four conceivable hypotheses: (1) that the
robbery was committed by Reuben Hornby; (2) that it was committed
by Walter Hornby; (3) that it was committed by John Hornby, or (4)
that it was committed by some other person or persons.
"The last hypothesis I propose to disregard for the present and confine
myself to the examination of the other three."
"You don't think it possible that Mr. Hornby could have stolen the
diamonds out of his own safe?" I exclaimed.
"I incline at present to no one theory of the matter," replied Thorndyke.
"I merely state the hypotheses. John Hornby had access to the
diamonds, therefore it is possible that he stole them."
"But surely he was responsible to the owners."
"Not in the absence of gross negligence, which the owners would have
difficulty in proving. You see, he was what is called a gratuitous bailee,
and in such a case no responsibility for loss lies with the bailee unless
there has been gross negligence."
"But the thumb-mark, my dear fellow!" I exclaimed. "How can you
possibly get over that?"
"I don't know that I can," answered Thorndyke calmly; "but I see you
are taking the same view as the police, who persist in regarding a
finger-print as a 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 important and significant one, I
admit--but still a fact, which, like any other fact, requires to be weighed
and measured with reference to its evidential value."

"And what do you propose to do first?" "I shall first satisfy myself that
the suspected thumb-print is identical in character with that of Reuben
Hornby--of which, however, I have very little doubt, for the finger-print
experts may fairly be trusted in their own speciality."
"And then?"
"I shall collect fresh facts, in which I look to you for assistance, and, if
we have finished breakfast, I may as well induct you into your new
duties."
He rose and rang the bell, and then, fetching from the office four small,
paper-covered notebooks, laid them before me on the table.
"One of these books," said he, "we will devote to data concerning
Reuben Hornby. You will find out anything you can--anything, mind,
no matter how trivial or apparently irrelevant--in any way connected
with him and enter 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, data concerning John Hornby. As to the fourth
book, you will keep that for stray facts connected with the case but not
coming under either of the other headings. And now let us look at the
product of Polton's industry."
He took from his assistant's hand a photograph ten inches long by eight
broad, done on glazed bromide paper and mounted flatly on stiff card.
It showed a greatly magnified facsimile of one of the thumb-prints, 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 visible to the naked eye.
Moreover, the entire print was covered by a network of fine black lines,
by which it was divided into a