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Simony's comparison of the bottom temperature of 

 the G'munder See with the winter temperature of the 

 air 296 



My observations in the Lochs of the Caledonian 

 Canal in Scotland . . . . . . .297 



The bottom temperature of even the deepest of 

 them varies from year to year. 



His observations covered the two very cold winters 

 1878-79 and 1 880-8 1. 



Up to this date it was universally believed and 

 taught that water below the ice of a frozen lake must 

 necessarily have a uniform temperature of 4 C. or 

 39-2 Fahr. This was held to follow as a corollary of 

 the demonstration that the density of pure water has 

 its maximum value at that temperature. In the first of 

 these winters, 1878-79, and on the first day that I sank 

 my thermometer below the ice of Loch Lomond in 

 the region between Balloch and Luss, I found all 

 the water from the ice to the bottom to have a tempera- 

 ture below 34 Fahr. and thus proved the corollary to 

 be a fallacy ......... 300 



Effect of wind in circulating the water of a Lake. 

 Observations irt other frozen Lakes . . .302 



Changes of level and seiches ..... 303 



Remarkable seiche in Loch Tay .... 305 



Changes of level due to meteorological causes . 307 

 Lake Tanganyika a remarkable example. 



Great interest of Central African lakes . . . 308 



Lakes without outlet ...... 309 



Table of data regarding some of these . . . 310 



No. 21. ON THE DISTRIBUTION OF TEMPERATURE IN LOCH 

 LOMOND DURING THE AUTUMN OF 1885. [From 



Proc. Roy. Soc. Edin., 1885, Vol. xin. p. 403] . . 312 



The observations reported in this paper were made 

 during a summer residence on the banks of Loch 

 Lomond, and the object of them was to obtain informa- 

 tion regarding the relation which exists between the 

 gain and loss of heat of the water of the lake and the 

 change of season. 



Loch Lomond is naturally divided into three basins, 



