12 



Indiana Uiiiversity Studies 



stratification of our lakes. The second factor is the depth of 

 the lakes. The deeper New York lakes have a greater capacity 

 for heat. This factor also delays the stagnation period. 



The following table gives the amount of wind-distributed heat 

 in the different types of Indiana lakes so far examined: 



Table III. Showing the Heat Content of Types op Indiana Lakes 









Wind- 



Lake 



Average 



Average 



distributed 





depth 



temperature 



heat 



Manitou 



2.997 



21.89 



5,361 



Yellow Creek 



10. 



15.45 



11,458 



Big Barbee 



6.7319 



19.6911 



10,563 



Plew 



7.327 



17.8833 



10,172 



Silver 



4.1172 



22.95 



9,438 



Little Eagle (Chapman) 



4.975 



24.713 



10,304 



The effect of the wind on the circulation of water in a lake 

 and the factors governing it are worthy a more detailed analysis 

 than, to the present time, has been given them. 



A priori, the shape of the basin, its size, depth, and exposure, 

 the relation of its major axis to the direction of the prevailing 

 winds are factors that enter into the problem. For example, 

 a small circular basin protected by high moraines (e.g. Center 

 lake) will become thermally stratified much sooner than if the lake 

 had low shores and were elongated in the direction of the pre- 

 vailing winds (e.g. Turkey lake). The nature of the currents, 

 i.e. their directions, depths, and changes, during continued wind 

 in various types of basins is not well known. 



Concerning the effect of the wind in the early spring, Birge and 

 Juday (1911, p. 27) say: '^The surface water will be blown across 

 the lake and when it reaches the leeward side it must return; 

 some of it will remain at the surface and return around the lake; 

 but probably the greater portion will turn down and return at 

 various depths, some of it returning along the bottom.'' 



In his report on the temperature of the Scottish lakes Wedder- 

 burn (1910, p. 125) states: '^Numerous observations were made 

 in Loch Ness after the discontinuity had appeared, and although 

 the results obtained were extremely complicated, it appeared that 



