This diary records the weather and appearances of birds, flowers, and insects.

This collection consists of correspondence, manuscripts, drawings, diaries, notebooks, and photographs. Sanderson began his travels in the jungles of Asia and Africa before starting his formal schooling at Eton and Cambridge in the late 1920s and early 1930s. His papers reflect his interest in animals, jungles, and natural history. Late in his life Sanderson's interest turned to UFO's and he was the director of the Society for the Investigation of the Unexplained.

These letters and papers include a memorandum book (1795-1827), lectures on botany and medicine, genealogical materials, committee reports from Columbia College, speeches, minutes of the New York Horticultural Society (1822-1828), letters to Sir James Edward Smith (1817-1826), a receipt book of Alexander Hosack (1781-1801), and diaries of Thomas K. Wharton (1830-1862).

The papers include miscellaneous letters, letterbooks, books, certificates, and diplomas of various members of the Muhlenberg family. Among them are photostats of letters and papers of General John Peter Gabriel Muhlenberg and officers of the Continental Army on military affairs in the Southern Department during the American Revolution (1772-1804); photostats of letters to Albert Gallatin, Nathanael Greene, Edward Hand, Winthrop Sargent, Baron von Steuben, William Alexander, and George Washington; photostat of General Muhlenberg's journal of trips to the Ohio (1784, 1797); photostats of letters and notes of Gotthilf H. E. Muhlenberg, including a diary kept at Halle (1771) and extracts of thirty letters to Stephen Elliott of Beaufort and Charleston, South Carolina (1808-1815); photostats of letters of Henry A. Muhlenberg about his biography of General Muhlenberg (1848-1849); and photostats of letters of Henry Melchior Muhlenberg (1711-1787). Also included is an original letterbook of Peter Muhlenberg, paymaster of the United States Army, kept at Augusta and Savannah, Georgia (1836-1842). Henry Muhlenberg's notebooks (1784-1813), written in Latin or German script, in a small hand, includes a wealth of botanical observations, with a focus on Lancaster, Pennsylvania. The Henry Muhlenberg journals are a record of daily occurrences, with many features of a commonplace book, containing prescriptions, notes of questions asked candidates for the Lutheran ministry, and the plan of a barn. There is also a biographical account of Rev. Henry Melchior Muhlenberg (1711-1787).

This collection includes letters from, and drafts of letters to, scientists, artists, musicians, soldiers, political figures, and court personages throughout Europe, especially Italy and France. Topics covered range from personal and social affairs to agriculture, botany, geology, natural history, coinage, museum management, politics, weights and measures, current affairs. The collection also includes four diaries, housed separately with manuscript volumes.