1846.] Meteorological Observations. 323 



pose this dark color of clouds over a large surface of water is 

 common, and accounts for the description of clouds at sea. 



Fall of Lake Ontario. — The water has been slowly falling for 

 months in this lake. The mouth of the Genesee atiords a place 

 for easy measurement, and the fact is certain. Not only is the 

 lake and the w^ater at the mouth of the Genesee river lower than 

 the same was a few years ago, but the fall has been considerable 

 in the last few months. The collector of the port has made the 

 following statement of the fall: 



Feel. lacbea. 



1845, June 1, water below top of wharf, 1 



Sept.l, " " " 2 1 



Oct. 1, " " " 2 6 



Nov. 1, " " " 2 9 



Dec. 1, " " " 3 1 



31, " " " 3 3 



The reason of this fall is, that less water has been poured by the 

 rivers info the lakes. It was announced sometime since that the 

 river at Niagara Falls was lower than ordinary. The last nine 

 months has been one of uncommon drought over a wide extent 

 of our country, and has been especially felt in the region around 

 the great lakes. The summer too was uncommonly warm, and 

 the evaporation from the land and lakes much greater. For both 

 reasons Lake Ontario has received less than its usual volume of 

 w^ater. It is seen by the measurements of the fall that it has been 

 much less rapid in the latter months of the year. The fall rains, 

 however, though considerable, were less than common, and a 

 continuance of the fall is to be expected till the streams shall be 

 abundantly supplied. An unusual amount of rain will be follow- 

 ed by a rise of the lakes. 



It is now well ascertained that there is no regular and periodi- 

 cal rise and fall of the lakes. A variation in their level occurs, 

 from time to time, on the principle and for the reason already 

 given. 



It might be expected perhaps that a greater evaporation should 

 be followed by a greater amount of rain. This is probably true 

 on the whole, but does not hold for any given section of country. 

 In Europe there appears to have been a wet summer and autumn, 

 while drouth rested on our land. It has been remarked that the 

 opposite sides of the Atlantic have different states in respect to 

 the quantity of rain. The drouth and heat may change the cur- 

 rents in the atmosphere, so that the evaporated water shall be 

 transferred to some other part of the world. It is more common 

 still that the northern and southern portions of our country have 

 different quantities of rain in the same season, and a dry season 

 at the north be attended by a wetter one at the south. 



