Lakes 293 



area will be about 150,000 square miles, while the whole 

 drainage area is only 537,000 square miles. Hence the water 

 eonveyed by the St Lawrence to the sea, rather more than 

 one-fourth falls on the surface of the water itself. Looking to 

 their great extent, we should have suspected them to be much 

 deeper than is found to be the case. The deepest, Lake 

 Superior, is no deeper than Loch Morar in Inverness-shire. 

 Comparatively shallow, however, as they are, the bottoms of 

 them all, with the exception of Erie, are several hundred feet 

 below the level of the sea. It has been supposed that in former 

 times this chain of lakes formed an arm of the sea similar 

 to the Baltic in Kurope, and in support of this view we have 

 the fact of the discovery of marine forms in Lake Michigan. 



In Asia, Lake Baikal is in every way comparable to the 

 great Canadian lakes as regards size. Its area of over 9000 

 square miles makes it about equal to Erie in superficial extent, 

 while its enormous depth of over 4000 feet makes the volume 

 I its waters almost equal to that of Lake Superior. Although 

 its surface is 1360 feet above the sea-level, its bottom is 2720 

 feet below it. A former connection with the ocean has been 

 ' laimed for this lake, owing to the fact that seals inhabit its 



rs. Other large lakes in Asia are mostly salt, and some lie 

 wholly below the level of the sea. Thus the surface of the Caspian 



^5 feet below that of the Black Sea, and the bottom at its 

 greatest depth is 3600 feet deeper. The Dead Sea is over 1300 

 feet deep, and its surface is 1272 feet below the Mediterranean, 

 so that its bottom is 2580 feet below the level of the sea. In tin- 

 Caspian seals are found. A former connection with the Red 

 Sea has been claimed for the Dead Sea, l>ut this is disallowed by 

 Peschel and others. Tin- Jordan valley, and the Sea of Tiberias 

 and the Dead Sea, lie on the line of an extensive fault, and it i- 

 el, timed that this depression in the surface occurred with the 

 n of the fault. Further evidence in support of the 



nent that the Dead Sea was never connected with the sea 

 is of a negative character, and con-i-t^ . hi ll\ in the fact that 



:ie fnrm-, have not been found in the waten <>f the Jordan 

 or of Lake Tiberia-. .md that -ilvrr i- absent Inun the 

 of the Dead Sea. 



