The papers of Abbott Lawrence Rotch include correspondence, writings, notes, photographs, maps, drawings, tables, charts, financial papers, newspaper clippings, printed matter, and other material. Rotch developed an early interest in meteorology as a young man that led him to establish in 1885 the Blue Hill Meteorological Observatory, near Boston, Massachusetts. Rotch was the first person in the world to use kites to record data about the upper atmosphere and later used balloons to carry various instruments to record and photograph atmospheric conditions. The bulk of the collection, 1903-1910, consists of letters to Rotch that are filed in the general correspondence, although the correspondence does contain a few drafts of Rotch's outgoing letters. The general correspondence, mainly between Rotch and meteorologists, aviators, and aircraft designers, relates chiefly to discussions about aeronautics and atmospheric experiments and observations. The letters include several exchanges with the United States War Department about the air flight trials of the Wright Brothers. Also included are letters relating to Rotch's writings, speech engagements, and his participation and interest in the International Aeronautical Congress at the Universal Exposition in 1904 in St. Louis, Missouri. A writings file in the collection contains notes and drafts of writings by Rotch, reflecting his interests in meteorology and aeronautics. Tables and charts document atmospheric measurements recorded by Rotch. Correspondents include Cleveland Abbe, James Allen, Louis P. Casella, Octave Chanute, Glenn Hammond Curtiss, Oliver L. Fassig, A. Hildebrandt, S. P. Langley, Percival Lowell, Alexander McAdie, James Means, Hermann W. L. Moedebeck, Edward C. Pickering, Charles Stewart Rolls, Sir Napier Shaw, Lǒn Philippe Teisserenc de Bort, and Robert DeCourcy Ward.