Peter DollondDied 2 Jul 1820 (born 1730).British optician, son of John Dollond. Peter, though lacking a theoretical background, invented the triple achromatic lens still in wide use, made substantial improvements in the astronomical refracting telescope, and improved navigation instruments of his day. In 1765, he placed convex lenses of crown glass on either side of a biconcave flint glass lens to make the achromatic triplet lens to further improve the correction of colour fringes. (In 1733, Chester Moore Hall had invented the achromatic lens system by joining a crown glass lens and a flint glass lens, which reduce chromatic aberration.) |
