{F. G. Hagemann; H. M. Hall; J. Halm; Hamburg Seewarte; Richard Hamer; W. J. Hanna; E. Hartwig; Georg Hartwig; Harvard College Observatory; Herbert Harvey; Margaret Harwood; W. Hassenstein}
{Clem Stoeckle; Julius F. Stone; P. W. Stoner; Clarence Strachauer; Samuel Wesley Stratton; George L. Streeter; Paul Stroobant; Georg Struve; Sunset Press; Sun Yatsen University Observatory; Swarthmore College Library; Eugene Swarzwald; Synchronome Co., Ltd}
{Joseph A. Hodam; C. Hoffmeister; Helen Sawyer Hogg; Melvin J. Hoirch; Hong Kong Royal Observatory; Inga Howard; Herbert A. Howe; J. Huizinga; Beatrice M. Humason; W. J. Hussey; Robert Maynard Hutchins}
{Edna Wadsworth; Heint Walentowsky; Gilbert T. Walker [folded]; O. R. Walkey; War Department [T. L. Coles; F. W. Coe]; J. G. Ward; Warner & Swasey Co.; Wasco County Library [Nina M. Moran]; Washburn College [Helen Whitaker]; Washburn Observatory [George C. Comstock]; Washington Academy of Sciences [Robert B. Sosman]; Washington, State College of [W. W. Foote]}
{Pacific Electric Railway Co. [incl to/from GEH]; Pacific Geographic Society [Humphrey Read]; Pan American Scientific COngress [José J. Bravo]; Paris Observatory; Const. Parvule; J. Newton Parker; Sir Charles Parsons; Pasadena Association; Pasadena High School and Junior College [Ida E. Hawes]; Pasadena Vocation Bureau [Marion de Paar]; A. W. Pawlow; Fred Pearson; Peckham Bros.; George B. Pegram; Walter M. Pegram; Peking Central Observatory; G. Edward Pendray}
{E. Valenta; George Van Biesbroeck; Marguerite Van Biesbroeck; H. C. Van Buskirk; Mabel Van Deusen; E. A. Varela; Ventura Abstract Co. [Charles Barnard]; A. Verschaffel; Vienna II Physical Institute [Georg Stetter]; Vitalait Laboratory, Inc. [Earle L. Ovington]; J. Voute. folded}
{Herbert Meredith Reese; F. P. Reilly; M. dos Reis; W. Reiter; Remeis Observatory, Bamberg; Rennselaer Polytechnic Institute Library; Republic Productions, Inc. [John T. Bourke]; D. J. Rhederg; E. W. Rice; Hugh S. Rice; C. R. Richards; Harold Richards; L. J. Richardson; R. G. D. Richardson; K. M. Richey}
