borrowed the method from him--is better for this purpose."

He drew from the portfolio a half-plate photograph of the thumb-print
which appeared magnified to about four inches in length. The print was
marked by a number of figures written minutely with a fine-pointed pen,
each figure being placed on an "island," a loop, a bifurcation or some
other striking and characteristic portion of the ridge-pattern.

"This system of marking with reference numbers," said Mr. Singleton, "is
better than your method of squares, because the numbers are only placed
at points which are important for comparison, whereas your squares or
the intersections of the lines fall arbitrarily on important or
unimportant points according to chance. Besides, we can't let you mark
our original, you know, though, of course, we can give you a photograph,
which will do as well."

"I was going to ask you to let me take a photograph presently," said
Thorndyke.

"Certainly," replied Mr. Singleton, "if you would rather have one of
your own taking. I know you don't care to take anything on trust. And
now I must get on with my work, if you will excuse me. Inspector Johnson
will give you any assistance you may require."

"And see that I don't pocket the original," added Thorndyke, with a
smile at the inspector who had shown us in.

"Oh, I'll see to that," said the latter, grinning; and, as Mr. Singleton
returned to his table, Thorndyke unlocked the microscope case and drew
forth the instrument.