314 ROCHESTER ACADEMY OF SCIENCE. [May 28, 



the benign effects of the great lakes, none receive so much benefit. 

 The explanation for this partiality is the peculiar situation of the city 

 with reference to the lakes in connection with the direction of the cold 

 waves. Lake Ontario lies directly in the way of the cold anticyclonic 

 waves that pass over this place. It is impossible for the cold waves 

 to sweep across the lake, during the time when the coldest waves 

 occur, without having the lower air warmed by the surface waters. 

 The greatest severity of the cold can not strike the city, although it 

 may be felt on the higher ground farther south. 



To appreciate this warming effect of 'the lake one should realize 

 the heat-storing capacity. Mr. Orin Parker has made an estimate as 

 follows : The mass of water is taken as 650 cubic miles. The cooling 

 of this mass through only five degrees of temperature would eliminate 

 as much heat as the combustion of 2,500,000,000 tons of coal. This 

 is five times the total quantity mined in a year in the whole world. If 

 these figures are not precise they at least give some idea of the magni- 

 tude of the forces which are at work. We have the sun heat stored 

 during summer and returned to us when most needed, for the cold 

 waves are moderated by the lake heat until late winter or spring 

 when the severest waves are past. 



No other city has lake protection to the same degree. Lake 

 Erie is too shallow to store so large an amount of heat, or Cleveland 

 might have some similar protection, but Cleveland is also exposed to 

 the cold waves which sweep down the Mississippi valley. Buffalo is 

 reached by the cold waves through the space between Erie and 

 Ontario. Oswego is so far east that the cold waves reach it around 

 the east end ot the lake. Indeed the lowest temperatures at Roches- 

 ter have been due to the cold waves passing east of the lake and then 

 backing up on us, Syracuse is too far south and east. Lake Michi- 

 gan lies nearly on a meridian and its shores are therefore exposed, 

 while Huron and Superior, lying so far north, do not absorb so much 

 summer heat. Rochester has the beneficial effect of the three upper 

 lakes and in addition the fullest protection of Lake Ontario, Cer- 

 tainly no other city in America has a location so peculiarly fortunate 

 in respect to lake protection. 



WEATHER PREDICTIONS. 



The only prognostication of the weather (not climate) which has 

 any basis in knowledge, or any reliability, is that based on the obser- 



