The collection includes correspondence, manuscripts, printed material and ephemera all related to astronomer Francis Gladheim Pease, his astronomy work, and the telescopes he designed. There are 13 letters and an offprint, "Building the 200-Inch Telescope", by George Ellery Hale. There is an offprint of "The Spectra of Four of the Temporary Stars" written by Pease and Walter S. Adams. The correspondence includes: Giorgio Abetti, Walter S. Adams, John A. Anderson, Andrew Carnegie, Edward H. Davis, Elmer Grey, George Ellery Hale, Fred E. Harvey, Herbert E. Ives, Thornwell Jacobs, George Wharton James, Helen Keller, Albert A. Michelson, Robert A. Millikan, James R. Page, F. E. Wright, the Bausch & Lomb Optical Company, and Thomas Edison. The manuscripts include a "Figuring Book" which contains his work on and blueprints for various telescopes and a manuscript entitled "Notes on a 25-Foot Reflector." The ephemera is made up of printed offprints, a blueprint of the telescope at Mt. Wilson, newspaper clippings, miscellaneous items, and articles from several websites regarding Einstein, telescopes, Mt. Wilson, the Palomar Observatory and the Comet Hale-Bopp. The photographs include a portrait of George Ellery Hale (1929), three photographs of the construction of the telescope at Palomar Observatory (1937), and a photograph of Albert Einstein with Charles St. John, Ferdinand Ellerman, Walther Mayer, and Edwin Hubble on the steps outside the 150-foot tower telescope during Einstein's second visit to Mt. Wilson (January 1931).