200 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
less preceptible than it otherwise would be. The summers of Mus- 
koka are cooler than those of any other part of Ontario south of 
the 47th parallel of latitude. But this tempering of the heat 
is due in large measure not so much to the influence of the Georgian 
Bay as to general elevation and the number of small lakes of great 
depth and coolness. Like the Ottawa Valley, though not to the same 
degree, the district is open to cold northerly winds in winter blowing 
outward from such centres of high pressure as move eastward to the 
Atlantic in high latitudes. Elevation adds to the cold of these north 
winds, which however are infrequent in some winters. At Hunts- 
ville (about lat. 45° 15’) in Eastern Muskoka, the temperature in 
January 1882 during the passage of almost the only severely cold 
anti-cyclone of the season, fell under a north wind to a temperature 
30° lower than was reached at Toronto, and actually 47° lower than 
at Windsor, less than three degrees further south and little more 
than 280 miles distant in a direct line. In severe winters, a large 
part of the Georgian Bay, encumbered with islands, freezes over and 
the tempering effect of the lake water is thus greatly diminished. 
The winters of the large island of Manitoulin, which’ approaches 
the 46th parallel, are milder than those of Muskoka. Of the climate 
of the north shore of Lake Huron beyond the 46th parallel, the 
meteorological records are meagre. The district is protected against 
cold west winds in winter by Lake Superior, but is open to cold 
blasts from the north-west, north, and north-east. The winter 
isotherm of 20° skirts the coast ; inland the winters are colder. The 
summers are said to be warmer than those of Muskoka, notwith- 
standing the higher latitude. Small lakes are less numerous, and 
are shallow and heat rapidly. Neighbourhood to the great 
breadth of land between Lake Huron and James’ Bay—an area which 
sometimes becomes intensely heated in summer has probably also some 
effect on the summers of the district. The heat of the southerly 
winds is of course greatly tempered by the great length of Lake Huron 
stretching against them. 
At a distance of from 1Z to 20 miles north of the north shore of 
Lake Ontario extends from the Highlands of Grey in peninsular 
Ontario to the head of the Bay of Quinte, a ridge or watershed 
attaining at a few places an elevation of nearly one thousand feet 
above the sea, and doubtless having some effect on the climate of the 
basin of Lake Ontario. Eastward from the easterly termination of 
