I went into the office, where our coats hung, and brought back the
notebook with the little board to which it was still attached by the
rubber band. Thorndyke took them from me, and, opening the book, ran
his eye quickly down one page after another. Suddenly he glanced at the
clock.

"It is a little late to begin," said he, "but these notes look rather
alluring. I am inclined to plot them out at once. I fancy, from their
appearance, that they will enable us to locate the house without much
difficulty. But don't let me keep you up if you are tired. I can work
them out by myself."

"You won't do anything of the kind," I exclaimed. "I am as keen on
plotting them as you are, and, besides, I want to see how it is done. It
seems to be a rather useful accomplishment."

"It is," said Thorndyke. "In our work, the ability to make a rough but
reliable sketch survey is often of great value. Have you ever looked
over these notes?"

"No. I put the book away when I came in and have never looked at it
since."

"It is a quaint document. You seem to be rich in railway bridges in
those parts, and the route was certainly none of the most direct, as you
noticed at the time. However, we will plot it out and then we shall see
exactly what it looks like and whither it leads us."

He retired to the laboratory and presently returned with a T-square, a
military protractor, a pair of dividers and a large drawing-board on