Thomas Hubbard Sumner (20 March 1807 – 9 March 1876) was a sea captain during the 19th century. He is best known for developing the celestial navigation method known as the Sumner line or circle of equal altitude. (From Wikipedia)
More about Thomas H. Sumner:Books by Thomas H. Sumner:
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Sumner, Thomas H.: A New and Accurate Method of Finding a Ship's Position at Sea, by Projection on Mercator's Chart (second edition; Boston: T. Groom, 1845)- Sumner, Thomas H.: A New and Accurate Method of Finding a Ship's Position at Sea, by Projection on Mercator's Chart (third edition, revised; Boston: T. Groom and Co., 1851) (page images at HathiTrust)
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