HYDROG'RAPHY (from GI:. Gdwp, hyd4r, water -I- -)paom, -graphic, writing, from }paters, gra Orin. to write). That branch of the science of physical geography which treats of the surface waters of the earth particularly with reference to their bearing on 1141V 1,tfa jolt. Practically every civilized nation. and particularly all maritime nations. have special governmental whose duty it is to survey and chart the naviga ble waters belonging to the nation, and also the waters of the oceans wherever navigation ex tends. The hydrographieal work performed by these organizations may be divided into two branches: (1) The collection of hydrographie data; and (2) the recording of these data. and marking the records available for the mariner-. In the succeeding discussion these two branehes of hydrographic work will be considered sepa rately. First, however, it will be interesting to note very briefly the earliest attempts at sys tematic hydrographie work. The first step in the modern science of hydrography was made in the fifteenth century by Henry, 'The Navigator,' who was the first to construct a sea chart worthy of the name. Not mulch of importance in the way of hydrographie work was accomplished, however, until Captain James Cook, of the Eng lish Navy, commenced his long career of ocean surveying in 1759. Captain Cook's first work was the hydrographie mapping of the Saint Law rence River from Quebec to the Atlantic Ocean, which he accomplished while stationed with the British fleet eoitperating with General Wolfe in the attack upon Quebec. In 1763 Captain Cook was sent to survey the coast waters of New foundland. and in 1704 lie performed a similar duty for the coast of Labrador, and thereafter he continued similar hplrographic observations wherever lie was ordered until his death in 1779.
The French had been observers of the operations of Captain Cook. and in 17S5 La Pi-rouse was sent with two ships and a corps of scientists to visit the northwest coast of -America and to ex plore other parts. Ile made important observa tions there. and also on the northeast coast of Asia. After spending two years and a half he went to Botany Bay, after which he was never heard from. except that information was obtained seven or eight years afterwards which made it probable that the ships were wrecked on a coral reef on the coast of Jlallicollo. La Thcrouse had, however, sent duplicates of charts and journals up to the time of his arrival at Botany Bay. The navigating officer of the expedition, Beau temps-Beauprci, sent out to search for La PGrouse in 1791 under the command of D'Entrecasteaux, wrote a work on marine surveying, which was published in an appendix to the narrative of the voyage (1808). This, however, had been preceded by Alexander Dalrymple's essay on marine sur veying, published in 1771. Beautemps-Beaupr6 was placed in charge of the survey of the French coast, where he trained a number of hydrogra pliers. the commencement of a corps of engineers tor future exploration and surveying. The work done by these early English and French naviga tors was imitated by those of other nations, and now, as previously stated, practically every civilized nation has its hydrographic office.