Ernst Mayr Library, Museum of Comparative Zoology

Thayer Expedition Papers

Also see: Burkhardt Collection

In April 1865, Museum of Comparative Zoology founder and director Louis Agassiz set off for Brazil with his wife Elizabeth and a dozen assistants on a fifteen-month collecting expedition financed by Boston banker Nathaniel Thayer. Agassiz’s primary goal was to investigate the distribution of Brazil’s freshwater fish species.

The Ernst Mayr Library’s Thayer Expedition Papers include field notes, specimen lists, correspondence, diaries, sketches, and other materials, digital images of which can be accessed through the following links:

• Agassiz, Alexander. 1 letter to Auguste Mayor, 9 December 1865, photostatic reproduction (bAg 10.10.34a).
• Agassiz, A., and Agassiz, Louis. Lists of specimens (bAg 826.50.1).
• Agassiz, Elizabeth Cary. 2 letters to Nathaniel Thayer (bAg 13.10.6).
• Agassiz, Louis. 1 letter to Tom Ward, 6 June 1865 (bAg 15.10.54).
• Agassiz, L. Lists of specimens with correspondence, primarily to A. Agassiz (bAg 826.50.2).
• Agassiz, L. Notes on Brazilian fishes (bAg 15.41.6).
• Agassiz, L. Notes on Brazilian fishes (bAg 15.42.4).
• Agassiz, L. Catalogue systematique de tous les poissons de l’Amazone (bAg 15.41.7).
• Bellows, F.W.G. 1 letter to William Gray, 29 July 1865, writing for Pacific Mail Steamship Company, New York, concerning Thayer Expedition (bAg 826.30.1).
• Cary, Thomas Greaves. 1 letter to A. Agassiz, 20 April 1866, Maldonado, Uruguay (bAg 188.10.1).
• Hartt, Charles, and Copeland, Edward. Catalogue of contents of can no. 4, Cannavieiras Collection (bAg 437.50.1).
• Hunnewell, Walter. 1 letter to Samuel Henshaw, 19 September 1918, concerning Thayer Expedition photograph (bMu 1498.10.1).
• James, William. Brazil diary, 1865 (bMu 1556.41.1).
• St. John, Orestes. Lists of fishes, 1865 (bMu 2411.50.1).
• St. John, O. List of fishes, 1866 (bMu 2411.50.2).
• St. John, O. List of fishes, for Louis Agassiz (bMu 2411.50.3).
• Thayer, Nathaniel. 1 letter to William Gray, 26 July 1865, resigning as MCZ treasurer (bMu 2761.10.1).
• Ware, H. 1 letter to George Ticknor, 25 April 1866, writing for John Albion Andrews, concerning Thayer Expedition, accompanied by enclosed letter from Jose Antonio Saraiva, writing for Pedro II, Emperor of Brazil, to John Albion Andrews, 15 December 1865, plus English translation of Portuguese original (bAg 826.30.2).
• A Thayer Expedition group photograph featuring Jacques Burkhardt, Joao Coutinho, D. Bourget, Newton Dexter, Walter Hunnewell, William James and Stephen van Rensselaer Thayer (Portrait Collection) is in HUL’s Visual Information Access catalog (VIA).
• Also, an item owned by Houghton Library (included in the MCZ’s Thayer Expedition LDI Project), "James, William, 1842-1910. Papers. [Notebook 4] Z: Brazilian diary and sketch book, 1865 (Houghton Library MS Am 1092.9 (4498))".

Among the assistants on the journey was Louis Agassiz’s personal and principal artist Jacques Burkhardt, whose fish watercolors and landscape paintings, a highlight of the expedition’s treasures, are in the Jacques Burkhardt Collection.

See also: A Journey in Brazil by Louis and Elizabeth Agassiz (Boston: Ticknor and Fields, 1868).