The general tendency towards scientific specialization has resulted in the erection, as it were, of separate laboratories for the study of certain specific features of the physical earth, each with its name-plate upon the door. From some of these--as from meteorology and geology--the geographer, in the course of the studies we have just outlined, borrows such data as are necessary to his purpose, and puts them to his special uses. It is no part of a history of geography to deal with that of meteorology or of geology, though both these sciences are fundamentally geographical, owe an obvious debt to exploration and travel, and make ample use of cartography. On the other hand, there are some departments of research which, though standing under their own names, are grouped perhaps more closely as offspring of physical geography. Such are oceanography (the study of the sea), limnology (the study of lakes), potamology (that of rivers). The last term might be justified on the ground that it helps to lighten the burden of different meanings which rests upon the term “hydrography”; it at any rate defines a clear field of study which, in view of its practical importance, has attracted much recent attention. The study of lakes--the depth, movement, and composition of their waters, the life in them, the physical nature of their basins--which was practically initiated by Professor F. A. Forel’s investigations of Lake Geneva published in 1892–94, has already a notable monument in the bathymetrical survey of the Scottish fresh-water lochs, completed under Sir John Murray’s direction in 1908.