This diary records the individuals and sights that he saw while in England. There are many observations of life in London, e.g. parks, buildings, paintings, food. Outside of London he visited many towns, including Manchester and its cotton mills as well as the steel mills of Birmingham. He relates his visit to Drury Lane and the dramatic performance of Sarah Siddons. Some of the people he met included Sir Joseph Banks, Sir Charles Blagden, Matthew Boulton, Joseph Priestley, William Pitt the Younger, and Benjamin Vaughan. He also visited and described the gardens at Kew. The diary includes several sketches, including the plan of Blenheim Palace, and also a table of distances traveled.

This microfilm contains correspondence from scientists, including Friedrich Wilhelm Bissell, 1816-1846 [from Deutsche Akademie der Wissenschaften, Berlin]; Matthew F. Maury, 1849-1859 [from National Archives, Washington, D.C.]; Paulus Usteri, 1789-1821 [from Bibliothèque Universitaire, Zurich; and Johann G. Galle, 1836-1858 [from Frau von Heinz, Schloss Tegal]. There is also correspondence from the Royal Society, London; Bibliothèque Nationale, Geneva; Göttingen University Library; British Museum; Massachusetts Historical Society; Bancroft Library of the University of California; Yale University; Henry E. Huntington Library; Library of Congress; the Alexander von Humboldt Kommission; Westdeutsche Bibliotek, Marburg; and Deutsche Staatsbibliotek, Berlin. The materials were, in general, collected by Helmut de Terra and contain correspondence with various scientists. A few items pertain to Humboldt's travels and general comments on American Indian linguistics.

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.