“The train stops at Wadsworth five minutes to change engines,” said Allan.
“So I drive a third pin right out along this Wadsworth line at the intersection of it and the 3.10 o’clock line. Now, what time does it reach Parkersburg?”
“At 5.50 P. M.”
“Well, here’s the 5.50 line, and here, at the bottom of the board, is the Parkersburg line. I drive a fourth pin there, draw the cord tight and tie it. Then I cut it off, and tie at the end this little tag marked ‘Number Four.’ Now what does that cord indicate?”
Allan, looking at the board, saw a line that ran roughly like this:
(For complete time-table, see diagram facing [page 60])
“Why,” he answered, after a moment, his eyes shining, “the cord indicates the exact time that the train passes every station along the line.”
“Exactly,” assented Mr. Schofield. “Now, just by way of illustration, we’ll put on a west-bound train next,” and he picked up the red ball. “We’ll take Number Three. At what time does it leave Parkersburg?”
“At 11.40 A. M.”