Graph in Otto's Encyclopedia (Ottův slovník naučný, 1901) showing the dependance of the water temperature and the depth in various places of the world ocean. a: in the Pacific between 3° N and 3° S ;b: in the Atlantic between 3° N and 3° S; c: in the mid-Atlantic at 36.5° N; d: in the south Indian Ocean at 35° S 83° E.