LOCAL OLULiTOLOOr. 79 



the spring when the ice thaws and the water is gathering its warmth for 

 summer. Hence, while this cause will produce a manifest difference in 

 temperature at particular seasons and on the coldest days^ it is not likely 

 that it will exert any very great influence on the general average of 

 temperature for the year ; but it will accomplish two important practical 

 results: (1) It will retard the spring so as to prevent the more delicate 

 fruits from putting forth so soon as to be in the way of the later frosts ; 

 and (2) it will put oft' the frosts in the autumn, so as to allow grapes and 

 other fruits that need a long season, to ripen better than they otherwise 

 would. 



If, now, inland towns like all those in the western and northwestern 

 part of our State, and those in States farther west and in Canada even, 

 are situated not on a lake merely, but in the neighborhood of a chain or 

 system of them, we shall have these inland bodies of fresh water exert- 

 ing an influence upon them all, and extending over a large tract similar 

 to what I have described, and similar, likewise, to some extent, to that 

 which I have ascribed to the greater bodies of salt water, in speaking of 

 inland distance. There can be no doubt, I think, that we are indebted 

 to this influence, largely, for the climate which renders our inland towns 

 and counties in central New York so productive. Like the Atlantic 

 ocean on the east of us, which, as already said, is exposed to more than 

 its normal share of the polar current by the position and course of the 

 great mountain ranges of the old continent, so our land is exposed to, 

 and receives far more than its due share of the same cold winds by 

 reason of the situation of the Rocky mountains. The polar current that 

 should pass over where they stand, is turned out of its course by them, 

 and deflected across the continent towards the Atlantic ocean; so that 

 our polar currents, which should come from a northeasterly direction, 

 come from the northwest, and are sometimes deflected so far that they 

 come to us from a point of the compass that is some degrees to the south 

 of Avest. Hence it is, as I think, that the isothermal line of 50° for the 

 year, which should pass some 10° northward of us — latitude 43° — passes 

 across the continent from the moment it reaches the plains east of the 

 Rocky mountains in the northern part of Colorado, along in a direction 

 somewhat south of easterly until it reaches and passes by the longitude 

 of the great lakes, and then turns to a direction north of east until it 

 reaches its normal parallel of latitude, 50°, about the middle of the 

 Atlantic ocean, and after it has crossed and been warmed by the Gulf 

 stream. 



