CURRENCY

(Lat. curro, / run.) In Political Economy, a term sometimes used to expre the collective amount of the money, and of the bills, cheques, and other substitutes for money, employed in selling or buying, or in the distribution of commodities and services among the different ranks and orders of the community. CURRENT (Lat. curro.), denotes in its most general sense the progre ive movement of any object; but it is applied chiefly to the progre ive movement of fluids, especially of air, electricity, and water. Currents in the ocean arise from various causes, either occasional or constant. They may be occasioned by an external impulsion, for example a gale of wind; from a difference in the temperature of different parts of the sea; from the inequality of evaporation, the melting of the polar ice, or in short any cause tending to disturb the hydrostatic equilibrium. It is difficult in many cases to trace their causes, or to give any satisfactory theory of tlieir existence; but on account of their importance to navigation they have been observed, especially of late years, with great care. Among those which have a permanent or general character, there are two which are very remarkable. The first is that of the tropical waters westward round the globe, and the second that which constantly flows from each pole towards the equator. The tropical or westerly current is chiefly confined within the zone extending to about 30° on each side of the equator, and its velocity is estimated by Humboldt at about nine or ten miles a day. In the Atlantic it separates into two branches; one of which forms the gulf stream s and the other flows along the cor.st of Brazil, and pa es through the Straits of Magellan. The gulf stream flows northward through the middle of the Atlantic, till it reaches the Cape Verd Islands; it then pa es through the Caribbean Sea, between Cuba and the peninsula of Yucatan, sweeps round the Gulf of Mexico, and rushes out by the Bahama Channel; then, spreading out to a greater breadth, it continues its course along the shores of the United States to Newfoundland, where it is deflected eastward by a current setting in from Baffin's Bay; and, pa ing the Azores and Canary Islands, returns in a great measure into itself. Its breadth is 51 leagues in the Bahama Channel, and velocity from 3 to 5 miles an hour. {Murray's Geography, p. 186.) The polar currents flo^ constantly from the poles towards the equator, though it is evident that their sources must be supplied by currents in a contrary direction. Their existence is proved by the great ma es of ice which are carried every year from the polar seas to tropical latitudes. Oceanic currents, by carrying with them the temperature of the regions whence they flow, contribute in no small degree to modify the temperature of the atmosphere, and give a character to the climate of the countries to which they are contiguous. On the parallel of New York Humboldt found the temperature of the gulf stream 72° of Fahrenheit, while out of the current the heat of the ocean at the surface was only 63°. The current which flows X2 [s. 320]