The universal geography : earth and its inhabitants

110 THE NORTH-EAST ATLANTIC.pole to polo was at a uniform temperature of 40° Fahr., a temperature which waswrongly assumed to be that of the point of maximum density.In the North Atlantic, as in other seas, the temperature diminishes from thesurface downwards, but not uniformly. In certain strata the fall is measured onlyby tenths of a degree for hundreds of yards, whereas in the liquid masses fartherdown there are sudden falls of several degrees. These serious differences canonly be explained by the volumes of water which here meet from various quarters.Thus, from the depth of 50 to 500 fathoms, the waters of the Atlantic betweenIreland and Rockall cool very slowly, for this zone is covered entirely by the warmmass flowing from the tropical seas. But from 500 to 750 and 1,000 fathoms the5. Fall of Temperature in the Lotver Depths of the Atlantic, West of Ireland.According to Sir Wyvillc Thomson.j