HYDROGRAPHY, the science dealing with all the waters of the earth's surface, including the description of their physical features and conditions; the preparation of charts showing the position of lakes, rivers, seas, the contour of the sea-bottom, the position of shallows, deeps, reefs and the direction and volume of currents ; a scientific description of the position, volume, configu ration, motion and condition of all the waters of the earth. See also SURVEYING : Nautical, and OCEAN AND OCEANOGRAPHY. The Hydrographic department of the British Admiralty, established in makes charts for the admiralty, and is under the hydrog rapher to the admiralty. The corresponding Hydrographic Office in the United States was established in 1866 in connection with the Bureau of Navigation in the Navy department. (See CHART.)