sea-gauge

The Sailor's Word-Book

An instrument used by Drs. Hale and Desaguliers to investigate the depth of the sea, by the pressure of air into a tube prepared for the purpose, showing by a mark left by a thin surface of treacle carried on mercury forced up it during the descent into what space the whole air is compressed, and, consequently, the depth of water by which its weight produced that compression. It is, however, an uncertain and difficult instrument, and superseded by Ericson's patent, working on the same principle, but passing over into another tube the volume of water thus forced in. (See water-bottle.)

Related Words