USS Loggerhead (SS-374) USS Loggerhead (SS-374) USS "Loggerhead" (SS-374/AGSS-374), a "Balao"-class submarine, was a ship of the United States Navy named for the loggerhead, "Caretta caretta", a very large, carnivorous sea turtle common in the warmer parts of the Atlantic, Pacific, and Indian Oceans. "Loggerhead" (SS-374) was laid down on 1 April 1944 by Manitowoc Shipbuilding Co., Manitowoc, Wisc.; launched 13 August 1944; sponsored by Mrs. Barbara Fox; and commissioned on 9 February 1945, Commander Ralph M. Metcalf in command. "Loggerhead" emerged from the Manitowoc River into Lake Michigan on 1 March 1945 and headed via Chicago to Lockport, Ill., where she entered
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to