[Illustration: Map of train route.] He had said it was not more than half a mile; but this half-mile grew to five eighths as he became more accurate and serious. "Well," said he, now resuming the thread of his story, "it was Todhunter put it into my head. He owns he did. Todhunter says, says he, 'Joslyn, what's the use of crooking round all these valleys, when it would be so easy to go across?' "Well, sir, I saw it then, as clear as I see it now. When that trip was done, I had two days to myself,--one was Sunday,--and Todhunter had the same; and he came round to my house. His wife knew mine, and we liked them. Well, we fell talking about it; and I got down the Cyclopædia, and we found out there about the speed of cannon-balls, and the direction they had to give them. You know this was only talk then; we never thought what would come of it; but very curious it all was." And here Mr. Joslyn went into a long mathematical talk, with which I will not harass the reader, perfectly sure, from other experiments which I have tried with other readers, that this reader would skip it all if it were written down. Stated very briefly, it amounted to this: In the old-fashioned experiments of those days, a cannon-ball travelled four thousand and one hundred feet in nine seconds. Now, Joslyn was convinced, like every other engineman I ever talked to, that on a steep down-grade he could drive a train at the rate of a hundred miles an hour. This is thirteen hundred and fourteen feet in nine seconds,--almost exactly one third of the cannon-ball's velocity. At those rates, if the valley at Chamoguin were really but five eighths of a mile wide, the cannon-ball would cross it in seven or eight seconds, and the train in about twenty-three seconds. Both Todhunter and Joslyn were good enough mechanics and machinists to know that the rate for thirty-three hundred feet, the width of the valley, was not quite the same as that for four thousand feet; for which, in their book, they had the calculations and formulas; but they also knew that the difference was to their advantage, or the advantage of the bold experiment which had occurred to both of them when Todhunter had made on the tender his very critical suggestion. The reader has already conceived the idea of this experiment. These rash men were wondering already whether it were not possible to leap an engine flying over the Chamoguin ravine, as Eclipse or Flying Childers might have leaped the brook at the bottom of it. Joslyn believed implicitly, as I found in talk with him, the received statement of conversation, that Eclipse, at a single bound, sprang forty feet. "If Eclipse, who weighed perhaps one thousand two hundred, would spring forty feet, could not my train, weighing two hundred tons, spring a hundred times as far?" asked he triumphantly. At least, he said that he said this to Todhunter. They went into more careful studies of projectiles, to see if it could or could not.