94 Canadian Record of Science. 



the temperature of twenty-two and a half degrees ; whilst 

 l3etween forty-five feet and the bottom at ninety-nine feet 

 the further fall is only five degrees. In Lake Memphre- 

 magog, which is a deep-water lake lying in a higher 

 altitude, in the lap of the mountains in the south-eastern 

 sections of the province of Quebec, I found in August, 

 1892, the temperature of the surface water varying 

 between 71° and 74° F. according to time of day and clear- 

 ness of sky; at 36 feet deptli, 57° F. ; at 72 feet, 51° F. ; 

 at 288 feet, 48° F. ; and at 324 feet, 44-f F. Thus at 72 

 feet the Lake-on-the-Mountain waters were about eight 

 degrees colder than those of Lake Memphremagog in the 

 year named, and the bottom temperature at ninety-nine 

 feet was actually nearly three degrees colder than the 

 Memphremagog waters at three hundred and twenty-four 

 feet depth. 



The deeper waters of Lake Memphremagog, I have else- 

 where sucrgested, do not mingle with the warmer surface 

 waters. These — deri^'ed from the mountain streams and, 

 more directly, from the rains— continue their course 

 down the lake, like a surface river, over the colder waters 

 beneath, until they discharge into the ]\Iagog Eiver. 

 Here at the Lake-on-the-Mountain it can hardly be sug- 

 gested that the deeper waters are more or less stationary, 

 as the height above the Bay of Quinte and the general dip 

 of the rocks in the district rather imply that the infiow is 

 at or near the bottom and througli small subterranean 

 crevices that must be much deeper still. The low tem- 

 perature of these deeper waters would seem to show that 

 the inflow comes from considerable depths and, especially, 

 from a great distance away, but that it is not a large 

 inflow is evident, not only by the outflow, which can be 

 accommodated in a pipe rather more than two feet in 

 diameter, but also by the fact that the in Mowing colder 

 water is not sufficient in volume to control in summer the 

 temperature of the upper thirty feet of the waters of the 

 lake. 



