did his reading by candle-light." He touched the seat and the back of the chair, and then examined his hand. "There's dust, but nowhere near a decade's accumulation. Some one has been browsing in this library rather recently; and he was dashed secretive about it. He didn't dare draw the shades or turn on the lights. He sat here with a single candle, sampling Tobias's brand of literature. And it apparently appealed to him, for this one saucer contains evidence of many bookish nights. How many other saucers of paraffin there were we don't know."
"The old lady could tell us who had a chance to put the key back this morning after hiding the galoshes," offered Heath.
"No one put the key back this morning, Sergeant. The person who was in the habit of visiting here wouldn't have stolen it and returned it on each occasion when he could have had a duplicate made in fifteen minutes."
"I guess you're right." The Sergeant was sorely perplexed. "But as long as we don't know who's got the key, we're no better off than we were."
"We're not quite through yet with our scrutiny of the library," rejoined Vance. "As I told Mr. Markham at lunch, my main object in coming here was to ascertain Tobias's taste in literature."
"A lot of good that'll do you!"
"One never can tell. Tobias, remember, bequeathed his library to the Police Department. . . . Let's see with what tomes the old boy whiled away his inactive hours."
Vance took out his monocle and, polishing it carefully, fitted it to his eye. Then he turned to the near-
