dial, and it will jump frightfully. And the mode of estimating distance is very rough."
"That is all perfectly true," Thorndyke answered. "But you are overlooking certain important facts The track-chart that you will produce can be checked by other data. The house, for instance, has a covered way by which you could identify it if you knew approximately where to look for it. Then you must remember that your carriage is not traveling over a featureless plain. It is passing through streets which have a determined position and direction and which are accurately represented on the ordnance map. I think, Jervis, that, in spite of the apparent roughness of the method, if you make your observations carefully, we shall have no trouble in narrowing down the inquiry to a quite small area. If we get the chance, that is to say."
"Yes, if we do. I am doubtful whether Mr. Weiss will require my services again, but I sincerely hope he will. It would be rare sport to locate his secret burrow, all unsuspected. But now I must really be off."
"Good-bye, then," said Thorndyke, slipping a well-sharpened pencil through the rubber band that fixed the notebook to the board. "Let me know how the adventure progresses—if it progresses at all—and remember, I hold your promise to come and see me again quite soon in any case."
He handed me the board and the lamp, and, when I had slipped them into my pocket, we shook hands and I hurried away, a little uneasy at having left my charge so long.
