ABBOT, Henry Larcom, soldier, born in Beverly, Massachusetts, 13 August 1831. He was graduated at West Point in 1854, and made brevet second lieutenant of topographical engineers. His first service was in the office of the Pacific railroad surveys in Washington, whence in 1855 he was transferred to the Pacific railroad survey of the route between California and Oregon, and afterward served on the hydrographic survey of the delta of the Mississippi river. During the civil war he was principally engaged as a military engineer, and rose by successive steps until brevetted brigadier-general, United States army, 13 March, 1865, and made lieutenant colonel of engineers, 31 March, 1880. He served in various actions, and was wounded at Bull Run in 1861. Since the close of the war he has been engaged in superintending the defenses of the East river; in command of the engineer post and depot at Willet's Point, New York, and of the engineer battalion and the engineer school of application, the latter of which he has created. He was a member of the expedition to Sicily to observe the solar eclipse in 1870, member of the engineer board on the United States military bridge equipage and drill, of one on a plan for the protection of the alluvial region of the Mississippi against overflows, and of various other boards connected with fortifications and River and harbor improvements. He invented and developed the United States system of submarine mines for coast and River defense, 1869 to 1886. He has published "Vol. VI., Pacific Railroad Reports" (Washington, 1857); "'Physics and Hydraulics of the Mississippi," jointly with Capt. A. A. Humphreys (Philadelphia, 1861); "Siege Artillery in the Campaign against Richmond" (Washington, 1867); "Experiments and Investigations to develop a System of Submarine Mines for defending Harbors of the United States" (1881); jointly with boards and commissioners, "United States Bridge Equipage and Drill" (1870); "Reclamation of the Alluvial Basin of the Mississippi River" (1875); "Report of Gun-Foundry Board" (1884); and "Report of the Board on Fortifications or other Defenses" (1886).