{Leo J. Scanlon; William C. Scarritt; Robert O. Schad; Paul W. Schenck; James A. B. Scherer; Frank H. Schleer; Carl Schleicher & Schüll; Hans W. Schneider; Dorothy E. Schoof; J. Schroeter; F. Schuerer; L. Schützenberger; A. Schwassmann}
[J. Samuel Salvo; James Schenck; Cor Scheffers; Margaret Hale Scherer; Herbert W. Schneider {incl c.ltr JAAnderson to HWS; ltr HWS to JAAnderson}; Martin Schwarzschild; The Science Press {Ruth H. Little}; G. D. Shallenberger; J. Shearer; Hiram Wilson Sheridan; Leslie E. Simon {director, Ordnance Department, Ballistics Research Laboratory, Aberdeen}; Edmund W. Sinnott; Charlotte M. Sitterly; V. M. Slipher; Gilbert B. L. Smith {Naval Ordnance Station, Inyokern}; Harvey C. Smith; W. R. Smythe; James T. Spalding; Sir Harold Spencer-Jones; Armand N. Spitz; Robert G. Sproul]
{C. E. Adams; Hans Christian Adamson; Agence de Libraire et de Publications; Dinsmore Alter; American Academy of Arts and Sciences; American Astronomical Society [Raymond Smith Dugan]; American Council on Education; American Mathematical Society [Marc H. Ingraham]; American Offset Printers; American Telescope Laboratories, Inc.; Genevieve Arduin; Merle Armitage; Associated Press; Association of Colleges and Universities of the Pacific Southwest [Charles T. Fitts; Ernest J. Jaqua]; J. Attarablas; Audiphone Co.; Automobile Club of Southern California. folded}
{J. S. Plaskett; E. Pringsheim; Hugh B. Rice, Co.; A. Lawrence Rotch; C. Runge; J. R. Rydberg; Fernando Sanford; J. A. B. Scherer; Arthur Schuster [incl ltr Mrs. Schuster ? FHS]}
{Salto Observatory; Sanborn, Vail & Co.; San Diego Business and Professional Women's Club; San Diego County Planning Commission; San Diego Scientific Library; E. Sanger-Sheppherd; W. W. Sargeant; A. P. Saunders; Frederick A. Saunders; George G. Saunders}
{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}
{Charlotte Bushnell Abbott; Julia Andrews; Dorothy Bach; Ruth E. Barnett; Della L. Bens; Mrs. Betty Trier Berry; Ronnie Best; Dorothy W. Block; Martha C. Borton; Anita Brown; Inez Mitchell [Mrs. S. M.] Brown; Keith Brown; Carolyn D. Burns [see also folder 48, A. J. CANNON]; Helen O. Burns}
