“What do you make the distance from the land?” Croyden asked.
“About one hundred yards—but it’s very difficult to estimate over water. It may be two hundred for all I can tell.”
“It is exactly three hundred and twenty-two feet from the Point to the near side of the ruins,” said Croyden.
“Why not three hundred and twenty-two and a half feet!” scoffed Macloud.
“I measured it this morning while you were dawdling over your breakfast,” answered Croyden.
“Hitched a line to the land and waded out, I suppose.”
“Not exactly; I measured it on the Government map of the Harbor. It gives the distance as three hundred and twenty-two feet, in plain figures.”
“I said you had a great head!” Macloud exclaimed. “Now, what’s the rest of the figures—or haven’t you worked it out?”
Croyden drew out a paper. “The calculation is of value only on the assumption—which, however, is altogether reasonable—that the light-house, when erected, stood on the tip of the Point. It 156 is now three hundred and twenty-two feet in water. Therefore, dividing ninety-two—the number of years since erection—into three hundred and twenty-two, gives the average yearly encroachment of the Bay as three and a half feet. Parmenter buried the casket in 1720, just a hundred and ninety years ago; so, multiplying a hundred and ninety by three and a half feet gives six hundred and sixty-five feet. In other words, the Point, in 1720, projected six hundred and sixty-five feet further out in the Bay than it does to-day.”
“Then, with the point moved in six hundred and sixty-five feet Parmenter’s beeches should be only eighty-five feet from the shore line, instead of seven hundred and fifty!” Macloud reflected.