The Columbia Encyclopedia, Sixth Edition. 2001-07.
Dollond, John
(dl´nd) (KEY) , 170661, English optician and inventor. A silk weaver, he taught himself languages, mathematics, and science, becoming a noted scholar as well as a scientist. He invented the achromatic lens, which led to the construction of telescopes free of color fringes, and the heliometer, used in astronomical measurement.