"You turned round at once, I understand," said Thorndyke, "so we draw no line in that direction. The next is?"
"'Eight fifty-eight minutes, thirty seconds, East by North'; and the next is 'Eight fifty-nine, North-east.'"
"Then you traveled east by north about a fifteenth of a mile and we shall put down half an inch on the chart. Then you turned north-east. How long did you go on?"
"Exactly a minute. The next entry is 'Nine. West north-west.'"
"Then you traveled about the seventh of a mile in a north-easterly direction and we draw a line an inch long at an angle of forty-five degrees to the right of the north and south line. From the end of that we carry a line at an angle of fifty-six and a quarter degrees to the left of the north and south line, and so on. The method is perfectly simple, you see."
"Perfectly; I quite understand it now."
I went back to my chair and continued to read out the entries from the notebook while Thorndyke laid off the lines of direction with the protractor, taking out the distances with the dividers from a scale of equal parts on the back of the instrument. As the work proceeded, I noticed, from time to time, a smile of quiet amusement spread over my colleague's keen, attentive face, and at each new reference to a railway bridge he chuckled softly.
"What, again!" he laughed, as I recorded the
