CURRENT, in hydrography, a stream or flux of water in any direction. In the sea, they are either natural, occasioned by the diurnal motion of the earth round its axis, or accidental, caused by the waters being driven against promontories, or into gulfs and straits, where, wanting room to spread, they are driven back, and thus disturb the ordinary flux of the sea. Dr Halley makes it highly probable that in the Downs, there are under-currents, by which as much water is carried out as is brought in by the upper-currents.