This includes communications or correspondence from such figures as A.D. Bache, Amos Bonsall, John F. Frazer, and M. F. Maury. There are reports by committees, such as those on agriculture, botany, horticulture, and meteorology.

Mentioned in these letters are personal affairs, experiments, Babbage's calculating machine, and his "Bridgewater Treatise," second edition.

These are letters to Quetelet primarily on the subject of astronomy (meteorological observations), including charts showing directions of shooting stars.

The manuscripts of father William Mitchell and daughter Maria Mitchell are not easily separated, and are treated here together. The collection includes William Mitchell's autobiography, his memoir of Judge Walter Folger of Nantucket, astronomical and meteorological observations, lectures, family and other correspondence.

This collection includes letters to and from Americans (including South America and the West Indies) and letters about America selected from the Society's manuscripts (Classified Papers, Letter Books, Letters and Papers, Royal Society Letters, Miscellaneous Correspondence, and other official groups) and from collections of private papers (Sir Charles Blagden, William Buckland, John Canton, Sir John F. W. Herschel, Sir Edward Sabine, and others). The documents range in time and character from John Winthrop, Jr., "A Description of the Artifice & Making of Tarr & Pitch in New England" (1662), to letters from Sir Thomas Edward Thorne to his wife describing the American West, where he was on a surveying party in the 1880s.

From the Board of Trustees of the Estate of Stephen Girard, these films are the complete archive of one of the largest mercantile and financial operations in the United States of his day. The collection includes correpondence, with translations of letters in French (139 reels). It also includes bank records, account books, ledgers, cash books, and journals; papers, documents, and records of trading voyages (arranged by vessel and date); records of Girard's country house, "The Place"; records of real estate, rents, etc.; prices current of ports of the world. There is a card index of correspondents and ships (14 reels). Included is a card file, a unique and invaluable research tool, this is an index of names and places and alphabetical abstracts of Philadelphia newspaper items and advertisements for the period covering ca. 1718-1795. Roach made a systematic search through eighteenth-century newspapers and several other sources, for biographical and subject information on Philadelphians and Pennsylvanians of the period. It is primarily biographical , but subject headings, such as "The Barracks," "Blue Lion, Sign of the," "Custom House," are scattered throughout. The source of each entry is cited, and there are brief annotations. There is also a miscellaneous assortment of volumes that were received with the Kane family papers.