Correspondence, certificates, and printed matter. Consists primarily of correspondence from family members, friends, and fellow scientists. Includes a group of personal letters from Myron A. Munson, Morley's college roommate and lifelong friend, some written while Munson was serving in the Union Army in 1864, and an extensive correspondence with a number of prominent European and American scientists. Subjects include Albert Einstein's theory of relativity, the atomic weight of hydrogen, automobiles, densities of oxygen and hydrogen and the ratio in which they combine to form water, the electric streetcar, the Michelson-Morley experiment, and the typewriter. Correspondents include Henry Edward Armstrong, Herbert Brereton Baker, R. Börnstein, Wilhelm Böttger, Charles Francis Brush, Frank Wigglesworth Clarke, Edward Salisbury Dana, James Dwight Dana, Harold Baily Dixon, Hugo Erdmann, Phillippe-Auguste Guye, Edward Hart, Walther Hempel, Francis Hobart Herrick, W.M. Hicks, Sir William Higgins, F.F. Jewett, Baron William Thomson Kelvin, S.P. Langley, Joseph Larmor, Thomas C. Mendenhall, Albert A. Michelson, Dayton Clarence Miller, Charles E. Munroe, William A. Noyes, Wilhelm Ostwald, Henry S. Pritchett, F.W. Putnam, William Ramsay, Baron John William Strutt Rayleigh, Ira Remsen, William A. Rogers, Frederick Soddy, and W.F.G. Swan.