CHAP. X.

MENTIONING the subject of the last chapter, to the celebrated Doc|tor Moyes, who, though blind, delivered a lecture upon optics, and delineated the properties of light and shade, to the Bosto|nians, Page  95 in the year one thousand seven hun|dred and eighty five; he exhibited a more astonishing illustration of the power of the touch. A highly polished plane of steel was presented to him, with a stroke of an etching tool, so minutely engraved upon it, that it was invisible to the naked eye, and only discoverable with a powerful magnifying glass; with his fingers he dis|covered the extent, and measured the length of the line.

This gentleman lost his sight, at three years of age. He informed me, that be|ing overturned, in a stage coach, one dark rainy evening, in England, when the carriage, and four horses, were thrown in|to a ditch, the passengers and driver, with two eyes a piece, were obliged to apply to him, who had none, for assistance, in extricating the horses. As for me, said he, after I had recovered from the aston|ishment of the fall, and discovered that I had escaped unhurt, I was quite at home Page  96 in the dark ditch. The inversion of the order of things was amusing. I, that was obliged to be led like a child, in the glar|ing sun, was now directing eight persons, to pull here, and haul there, with all the dexterity and activity of a man of war's boatswain.