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 Memph rem agog a Cold Water Lake. 
 
 By a, T. DRUMMOND. 
 
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" Beprinledfrom the Canadian Record of Science, April, 1893." 
 
 Memphremagog a Cold Water Lake. 
 
 By A. T. Drummono. 
 
 Lake Memph rem agog is the Loch Lomond of Canada, but, 
 being less easy of access from the great cities, does not 
 attract the tourist as does the Scottish lake. It is, how- 
 ever, not less beautiful. Fiora the summit of Owl's Head 
 there is a view that for beauty and breadth is probably 
 unsurpassed elsewhere in Canad.^, while at the lake margin 
 there are lovely scenic effects particularly in the evenings 
 when the purple hills are brought into bolder relief b}'- the 
 brilliant tints of the setting sun and are mirrored in the 
 waters of the lake. 
 
 Whilst the surrounding mountains and glens have an 
 interest to the botanist, und the whole environs of (he 
 lake present to the geologist u peculiar record of the pa^t, 
 the waters of the lake have in their temperatures a feature 
 of interest to which, in a word, I would like to draw 
 attention. Lake Memphremagog has a length of about 
 thirty miles, an area of thirty-seven square miles, and, 
 according to Sir William Logan, a surface level of tSG feet 
 above the level of the sea. Lake Superior, with Hs co'd 
 waters, is in higher latitude but is only 600 feet above the 
 sea level, whilst its deeper depths sink far beneath it. 
 The smaller and shallower lakes are, like the rivers, suscep- 
 tible to the equalizing influences of summer temperatures, 
 but, in the case of Lake Memphremagog, circum- 
 stances peculiar to itself, affect the conditions of heat 
 and cold in its waters. Whilst it is exceptionally high 
 above the sec, it is in many places of considerable depth. 
 Nearly opposite Owl's Head, the sounding lino, it is claimed, 
 has reached the depth of 600 feet, whilst near George- 
 ville, six miles further down the lake, there are places 
 
852 Canadian Record of Scietue. 
 
 where I have not found the b>ttoiTi at 325 feet. The oppo- 
 site shoreH at this point are about two milcH upai-t, and it 
 was here, about midway acioHS, that hist August the tem- 
 peratures were taken. Nogretti & Zambi-a's deep-sea 
 thermometer was used for ascertaining bottom records. 
 The following register made on 10th of August at 11 a.m. 
 ■ndor the conditions of strong sun and cloudless sky, indi- 
 •ates generally the results : 
 
 Air in shade 77.5° F. 
 
 Water 1" below surface 74° 
 
 do 6 fms. do 57.5° 
 
 do 12 do do 5P 
 
 do 48 do do 48° 
 
 do 54 do do 44.75° 
 
 The results establish the two facts, 
 
 1. That Lake iMemphremagog is a cold water lake whoso 
 bottom temperature at 54 fathoms is, in early August, as 
 low as 44.75° F. 
 
 2. That the high temperature of the sulfate at the same 
 period is only maintained for, relatively, a lew feet beneath, 
 beyond which the mercury falls rapidly to near the lowest 
 temperature. 
 
 At the head of the lake at Newport, the flow of water 
 from the small rivers vising in the Vermont hills, creates 
 a decided surface current past Newport, and although I 
 have not specially endevvored to trace this current onward 
 to the outlet at Magog, it is suggestive from the tempera- 
 tures that the warm waters from the neighboring rivers and 
 streams flow, river-like, over the colder waters of the lake, 
 just as the Gulf Stream, under a different influence, but 
 lightly skims the surface of a large portion of the broad 
 Atlantic Ocean. 
 
 To illustrate the relative temperatures, whilst th& ther- 
 mometer at 12 fathoms here i-egistered 51°, the waters of 
 Lake Ontario, at their outlet into the St. Lawrence, indi- 
 cated at the same depth, and at about the same period, 67°.