With a 4.25 in. objective lens and a focal length of 40 in., the refracting telescope was probably first used by Hale for solar work. In his advancing years Hale used it at his private observatory. Reportedly, it was later used in the site search for the Palomar telescope and also in optics courses at Caltech through the late 1950s. With wooden stand. Manufacturer: John Byrne, New York, 1885.