"Do you remember the cartridge I found in the cellar?"
"Yes, yes; but you did not pay much attention to it, I thought."
He looked gravely at me. "Stone, that cartridge probably corresponds in calibre to the one which was used in the murder of Mark."
"Ah!" said Moore. "I had a notion of that myself. Why did you not tell us your opinion before?"
"Because, when I found it, we were working on the Mansion affair only. I divined the value of the find; but why should I have mentioned it? I was not hunting the Mark murderer then."
"Quintus, you consummate fox—you worked Hallen well!"
"Not at all; business is business. What is the use of gossiping? There are no ladies to be entertained in my profession, Doctor."
He led the way to the parlor—we meekly following—to where a cluster of arms hung upon the wall: one of those ornaments of crossed swords, guns and a shield, so common in old houses.
He remarked that he had noticed these arms on his previous visit. He looked at a revolver hanging across the shield, with a pouch beneath it, and then suddenly, in surprise, said: "Last time I was here, a few weeks ago, there was a large old-fashioned revolver here of 44 or 45 calibre. I remember it well, being interested in firearms.
"This one now here is of a similar pattern and appearance, but of smaller calibre, and newer. Look! The cartridges in this pouch are of about 45 size; they belong to the old weapon and cannot be used with this one."