Dredging

the operation of removing mud, silt and other deposits from the bottom of harbors, canals, rivers docks, etc., by mechanical means. Maenigy | is also the operation of dragging the bottom of the sea in order to bring up oysters, or to procure shells, plants, and other objects fot scientific observation. The oyste! dredge is a light iron. frame with s scraper like a narrow hoe on one side and a suspending apparatus on the ether. To the frame is attached ¢ __ ee eina i bag made of some kind of netting to receive the oysters. The dredges used by naturalists are mostly modifications of or somewhat similar to the oyster dredge. Scientific dredging has of late a umed a high importance as making us acquainted with the life of deep-sea areas, Dred Scott Case, a notable case before the Supreme Court of the United States in 1856. A negro called Dred Scott, with his wife and two children, had been held as slaves by a Dr. Emerson in Mi ouri. After Dr. Emerson’s death, Scott and his family claimed to. be free, as having resided with their owner in JJlinois and Minnesota, free States. The decision was hostile to their claim, and they were held to be still slaves.