From the May 3, 1930, issue
By Science News
MOON’S SHADOW AT ECLIPSE PHOTOGRAPHED
Clouds over the sun broke away at Camptonville, Yuba County, California, two minutes before the total phase of the solar eclipse of the sun. Only the lightest haze remained, and the observations planned by the various expeditions located there were carried through successfully.
The Lick Observatory-Crocker expedition under the direction of Dr. J.H. Moore secured photographs of the spectrum of the solar atmosphere with two powerful spectographs fitted with plate holders moved by accurately tuned screens driven by motors to secure perfectly uniform speed. One spectograph recorded the spectrum in the violet-blue region from 3900 to 4650 Angstrom Units; the other, the spectrum in the orange-red region from 4861 to 6563 Angstrom Units. Both plates when developed proved to be in perfect focus. It will, of course, require months of careful study to interpret them fully.