The Adams Papers contains approximately 100 letters addressed to the astronomer Walter Sydney Adams, dating primarily from the period after his move to Mount Wilson Observatory in 1904. Much of the correspondence is relatively perfunctory, however a few letters include interesting scientific content, including Harlow Shapley discussing his photometric study of HV 3435 and interest in Alpha Circini, Arthur Compton's comments on Keener's photoelectric method, Svante Arrhenius on the possibilities of constructing a new observatory for the Swedish Academy of Sciences, and Arthur Eddington discussing the implications of the spectrum of the companion to Sirius. Among Adams' other correspondents are J. C. Kapteyn, James H. Jeans, Henry Norris Russell, Elihu Thomson, and Willem de Sitter.

Two letters in the collection deal specifically with instrumentation: H. Spencer Jones complains of the problems in the manufacture of optical glass in the post-World War I period, and Elihu Thomson writes about his manufacture of quartz disks and tubes. Typically, a few of the letters include interesting personal details. In addition to Edwin B. Frost's recommendation for a fellowship at the University of Chicago when Adams was a graduate student there, the collection includes a fine, long letter from Russell describing his trip in the Middle East, and Adams' correspondence with English colleagues during the First World War provides a glimpse of the stress on astronomical research in England and on Anglo-American relations.