This collection was assembled by Court and was partly used in the book, "The History of the Microscope" (with Reginald S. Clay, London, 1932). There is historical correspondence (including some by Court), documents, broadsides, and photographs, concerning microscopes and instruments. This includes material on Joseph Bonomi, James Epps, John Lee, Edward Nairne, and others. There is significant material on Cornelius Varley: account book, autobiographical sketch, watercolors and sketches, etc. This collection also contains a large number of deeds pertaining to the property of John Lee (1783-1866), Fellow of the Royal Society and an amateur astronomer. In addition, there are about 300 pamphlets, including early trade and auction catalogs, used by Court for his research.

The North Amercian Land Company ledger contains accounts with prominent men of the time; in additon to the ledger are numerous deeds and other documents involving Robert Morris.

This is a miscellaneous collection of deeds, indentures, and land surveys. Many names are represented, including James Claypole, Joseph Harrison, John Penn, Richard Penn, Thomas Penn, Zachariah Poulson, and William Shippen, Jr.

These are deeds and papers pertaining to the estate of Samuel Mifflin, et al., of Pennsylvania.

This collection contains minutes of the Society, 1781-1975; minutes of the directors of the Corporation, 1929-1947; membership book (with signatures of early members), 1785; and names of later members. There are also deeds to the meeting house and burying ground; treasurers' accounts; reports of officers and committees; bills and receipts for constructing, maintaining, and repairing the meeting house; cancelled checks; and letters to the Society and its officers, especially Samuel Wetherill, 1883-1884.

This collection is primarily correspondence, accounts, bills, and receipts of Anthony Morris, but also included is older material on the Morris family (deeds, indentures, etc.). The correspondence centers on two major topics: the settlement of the estate of a Baron de Kalb, and information concerning Morris' proposal to set up the Fellenberg Institution for agricultural education, on his estate at Bolton Farm in Bucks County, Pennsylvania.

This collection includes letters, deeds, receipts. There are several letters concerning the ordering and delivery of scales and weights to various banks, including the Farmers Bank of Virginia, and the U.S. Bank in Savannah, Georgia. There are numerous documents relating to the Voights, namely deeds, real estate transactions, and indenture contracts. There is also a copy of a letter from Elias Boudinot of the U.S. Mint in Philadelphia concerning directions for closing the Mint in case of a yellow fever outbreak (1803).

A collection of letters, legal papers and financial records of three generations of the prominent Philadelphia family. Spanning 1745-1955, detailed are the legal cases and political advocacy work of John Kintzing Kane (1795-1858), Robert Patterson Kane (1827-1906), and Francis Fisher Kane (1866-1955). Also includes correspondence, architectural drawings, and photograph albums of the Cope family. Robert Patterson Kane's daughter Eliza Middleton Kane (1863-1952) married the Philadelphia architect Walter Cope (1860-1902) in 1893. The APS papers of Elisha Kent Kane are in call no. B K132.