LAKE 



3300 



LAKE 



Lakes may be caused by natural collection 

 of water in extinct volcanoes, by rivers which 

 deposit silt until the natural outlet to the 

 sea is closed, by subsidence of portions of the 

 earth, by the melting of the ice in the Glacial 

 Period (which see) or by many other causes. 

 They occur in all parts of the world, but arc 

 more frequent in high than in low latitudes. 



Some lakes are at a considerable elevation 

 above sea level, while others, as in the case 

 of the Dead Sea, are many feet below that 

 level. Lake Titicaca, in the midst of volcanic 

 territory in South America, is 12,500 feet above 

 the sea; the Dead Sea is 1,292 feet below sea 

 level. Many basins of lakes have been scoured 

 out of the rocks by glaciers. In Minnesota 

 ;ilone it is estimated that there are nearly 

 10.000 lakes due to glacial action, and Cayuga 

 Lake (which see) in New York is another 

 striking example of glacial scouring. In addi- 

 tion to the numerous lakes found in all parts 

 of the world, there are equally numerous basins 

 in which lakes once existed. The lakes that 

 now exist will in time vanish, leaving basins 

 that will be rich for cultivation. 



The Great Lakes (which see) have been 

 formed partly by glacial action and partly by 

 the filling of river beds, causing the dammed- 

 np waters to overflow into the surrounding val- 

 leys. Some lakes are basins in which water 

 has accumulated, fed by rivers and mountain 

 streams, with the surplus waters drained off 

 by other rivers; others apparently have neither 

 inlet nor outlet. In contrast, others have 

 streams which bring a continual supply of 

 water, but which have no outlet. The Great 

 Salt Lake is a striking example of this. 



Effect Upon Temperature. The presence of a 

 large body of water, such as any one of the 

 Great Lakes, materially modifies the weather 

 conditions for several miles in every direction. 

 Xo matter how cold the weather may become 

 over a wide area, residents of such a lake dis- 

 trict do not suffer from temperatures as low 

 i- do their neighbors twenty miles inland. 

 Water practically ots no colder than 32 F., 

 the freezing point; it therefore warms the 

 colder surrounding air from 5 to as much as 

 15. In summer a large body of water never 

 >rm as the surrounding atmosphere, 

 therefore it cools the air perceptibly. 



Conditions of agriculture near large bodies 

 ol water are materially changed. The great 

 fruit belt of Michigan is along the east shore 

 of Lake Michigan, where the influence of the 

 winds from over the water so modifv an other- 



wise rigorous climate that small fruits flourish. 

 This great fruit belt is a comparatively nar- 

 row strip along the shore extending from the 

 southern point of the lake in Indiana north- 

 ward for over 200 miles. The grape and to- 

 bacco belt in New York lies along the shore? 

 of Lake Erie and Lake Ontario, and the pres- 

 ence of these large bodies of water has made 

 it possible to raise fruits of many kinds on 

 the other shore, in Southern Ontario, where the 

 climate would naturally bo too severe. W.F.Z. 



Consult Russell's Lakes of North America ; 

 Gilbert's Topographic Features of Lake Shores, in 

 United States Geological Survey, Fifth Annual 

 Report. 



Related Subjects.. The following lakes are 

 treated in their proper alphabetical order in these 

 volumes : 



AFRICA 



Albert Edward Nyanza Nyassa 

 Albert Nyanza Tanganyika 



Chad ' Victoria Nyanxa 



Aral 



Baikal 



Balkash 



ASIA 



Caspian Sea 

 Dead Sea 

 Galilee. Sea of 



Avernus 



Caspian Sea 



Como 



Constance 



Geneva 



Katrine 



Killarney 



Ladoga 



Maracaibo 



Lomond. Loch 



Lucerne. 'Lake of 



Lugano 



Maggiore. 



Neuchatel 



Onega 



Zurich 



SOUTH AMERICA 



Titicaca 



CNITED STATES 



Cayuga 



Champlain 



Erie 



George 



Great Lakes, The 



Great Salt Lake 



Huron 



Lake of the Woods 



Memphrema tfog 



Michigan 



Moosehead 



Okechobee 



Oneida 



Ontario 



Pontchartrain 



Rainy 



Saint Clair 



Salton Sea 



Seneca 



Superior 



Tahoe 



Utah 



