Page:Austin Freeman - The Mystery of 31 New Inn.djvu/61

This page needs to be proofread.
THORNDYKE DEVISES A SCHEME
57

we die. And now as to your method of locating this house. Here is a pocket reading-lamp which you can hook on the carriage lining. This notebook can be fixed to the board with an india-rubber band—thus. You observe that the thoughtful Polton has stuck a piece of thread on the glass of the compass to serve as a lubber's line. This is how you will proceed. As soon as you are locked in the carriage, light your lamp—better have a book with you in case the light is noticed—take out your watch and put the board on your knee, keeping its long side exactly in a line with the axis of the carriage. Then enter in one narrow column of your notebook the time, in the other the direction shown by the compass, and in the broad column any particulars, including the number of steps the horse makes in a minute. Like this."

He took a loose sheet of paper and made one or two sample entries on it in pencil, thus—

"9.40. S.E. Start from home.

9.41 S.W. Granite setts.

9.43. S.W. Wood pavement. Hoofs 104.

9.47. W. by S Granite crossing. Macadam—and so on. Note every change of direction, with the time; and whenever you hear or feel anything from outside, note it, with the time and direction; and don't forget to note any variations in the horse's pace. You follow the process?"

"Perfectly. But do you think the method is accurate enough to fix the position of a house? Remember, this is only a pocket-compass with no