University of Chicago Centennial Cataloguesback
Forty-inch telescope, Yerkes Observatory
Forty-inch telescope, Yerkes Observatory.

Four inches wider than the Lick telescope on Mt. Hamilton in California, the light-gathering capabilities of the Yerkes instrument allowed Hale and his colleagues to see farther and in greater detail than anyone ever had before. Hale attached his newly designed Rumford spectroheliograph to the telescope and used it to investigate the sun's internal characteristics. Hale was also the first to photograph low temperature red stars known as Secchi's fourth type.