Pease, Francis Gladheim (18811938), a United States astronomer and optician. Pease made photographic and spectrographic studies of the moon, the planets, star clusters, and nebulae. He also measured the diameters of stars with an interferometer. He helped to design the optical systems of the 100-inch (254-cm) and 200-inch (508-cm) telescopes of Mount Wilson and Palomar observatories. Pease was born in Cambridge, Massachusetts. He graduated from Armour Institute of Technology in 1901 and received advanced degrees in 1924 and 1927. Pease was an astronomer at Mount Wilson Observatory from 1911 until his death.