Page 407 - 89 history of astronomy_opt

erate size; but there was a difficulty in mak-
ing flint-glass lenses of large size. The first
actual inventor and constructor of an achro-
matic telescope was Chester Moor Hall, who
was not in trade, and did not patent it. To-
wards the close of the eighteenth century a
Swiss named Guinand at last succeeded in
producing larger flint-glass discs free from
striae. Frauenhofer, of Munich, took him
407