prints were, in reality, forgeries, executed with rubber or gelatine stamps. That is an outline of the case."
The close of this recital brought our meal to an end, and we prepared for our visit to the scene of the crime. Thorndyke slipped into his pocket his queer outfit—somewhat like that of a field geologist—locked up the photographs, and we set forth by way of the Embankment.
"The police have no clue, I suppose, to the identity of the murderer, now that the finger-prints have failed?" I asked, as we strode along together.
"I expect not," he replied, "though they might have if they examined their material. I made out a rather interesting point this morning, which is this: the man who made those sham finger-prints used two stamps, one for the thumb and the other for the four fingers; and the original from which those stamps were made was the official finger-print form."
"How did you discover that?" I inquired.
"It was very simple. You remember that Mr. Singleton of the Finger-print Department sent me, by Superintendent Miller, two photographs, one of the prints on the window and one of the official form with Belfield's finger-prints on it. Well, I have compared them and made the most minute measurements of each, and they are obviously