Personal and professional correspondence, including 25 long letters from Professor Henry F. Herbig; manuscripts (mainly speeches); specifications for patents in electrical fields; technical and personal photographs; and memorabilia. Included is a copy of the famous "shot in hand" x-ray photograph, ca. 1896, one of the first ever to be taken. This collection also contains the correspondence, manuscripts, documents, and memorabilia of Professor Pupin's daughter, Varvara Smith, and his son-in-law, Louis Graham Smith. His daughter's letters and documents deal with her financial difficulties, her administration of Pupin's estate and her claims against Columbia University. Louis G. Smith's letters deal with his anti-Communist sentiments and his manuscripts are mainly ideas for popular songs and plays. There are three letters (photostatic copies) to Smith from Dwight D. Eisenhower.