1868-1938. US astronomer, who made pioneer
studies of the Sun and founded three major
observatories. In 1889, he invented the
spectroheliograph, a device for photographing
the Sun at particular wavelengths. In 1897 he
founded the Yerkes Observatory in Wisconsin,
with the largest refractor, 102 cm/40 in,
ever built at that time. In 1917 he
established on Mount Wilson, California a 2.5
m/100 in reflector, the world's largest
telescope until superseded 1948 by the 5
m/200 in reflector on Mount Palomar, which
Hale had had planned just before he died.