ent the judge paused for a moment, pen in hand, and stared
at Thorndyke with his mouth slightly open, while the two experts looked
at one another with raised eyebrows.

"By what means do you consider that the mark was produced?"

"By means of a stamp, either of indiarubber or, more probably, of
chromicized gelatine."

Here Polton, who had been, by degrees, rising to an erect posture, smote
his thigh a resounding thwack and chuckled aloud, a proceeding that
caused all eyes, including those of the judge, to be turned on him.

"If that noise is repeated," said the judge, with a stony stare at the
horrified offender--who had shrunk into the very smallest space that I
have ever seen a human being occupy--"I shall cause the person who made
it to be removed from the court."

"I understand, then," pursued Anstey, "that you consider the
thumb-print, which has been sworn to as the prisoner's, to be a
forgery?"

"Yes. It is a forgery."

"But is it possible to forge a thumb-print or a finger-print?"

"It is not only possible, but quite easy to do."

"As easy as to forge a signature, for instance?" "Much more so, and
infinitely more secure. A signature, being written with a pen, requires
that the forgery should also be written with a pen, a process demanding
very special skill and, after all, never resulting in an absolute
_facsimile_. But a finger-print is a stamped impression--the finger-tip
being the stamp; and it is only necessary to obtain a stamp identical in
character with the finger-tip, in order to produce an impression which
is an absolute _facsimile_, in every respect, of the original, and
totally indistinguishable from it."

"Would there be no means at all of detecting the difference between a
forged finger-print and the genuine original?"

"None whatever; for the reason that there would be no difference to
detect."

"But you have stated, quite positively, that the thumb-print on this
paper is a forgery. Now, if the forged print is indistinguishable from
the original, how are you able to be certain that this particular print
is a forgery?"

"I was speaking of what is possible with due care, but, obviously, a
forger might, through inadvertence, fail to produce an absolute
_facsimile_ and then detection would be possible. That is what has
happened in the present case. The forged print is not an absolute
_facsimile_ of the true print. There is a slight discrepancy. But, in
addition to this, the paper bears