according to my own observation, tho'. Sr. Isaac was of a very serious, & compos'd
, yet I have often seen him laugh, & that upon moderate occasions. he had in his disposition, a natural pleasantness of temper, & much good nature, very distant from moroseness, attended neither with gayety nor levity. he usd a good many sayings, bordering on joke, and wit. in company he behavd very agreably; courteous, affable, he was easily made to smile, if not to laugh. beside his severe studys,
he frequently diverted himself with his tools in mechanical works. he made speaking trumpets, he ground, & polishd glasses, for microscopes, telescopes, prisms, spectacles, & all kind of optical purposes. He would work very hard upon these. & his constancy, & persevereance at it, was great. that wonderful invention of the reflecting telescope is his. he made that famous reflecting telescope, now in the repository of the Royal Society: & likewise that concave speculum, or burning glass of many lesser, all respecting one common focus, now in the same repository. they are all instances of his curious hand in workmanship; as well as of his wonderful penetration, into the nature of vision. when we read his book of optics [
], we are astonishd at his indefatigable attention to that nice, & abstruse subject; & the long course of his observations, &
