Dr. Holyoke's Estimate of the Excess of Ileal and Cold. 



70 



The number^ of cloudy days in these same twenty cities 

 was in 1785, upon a mean, one hundred and thirteen, or 

 one hundred and fourteen; but at tJambridgo there were 

 only sixty nine ; and at Salem, upon aj^ mean of seven years, 

 about ninety five days annually. 



• 



The number of clays^ whicli were partly cloudy, in those 

 same cities was one hundred and seventy four^ or one bund- 



■ 



red and seventy five ; at Cambridge but one hundred and 



twenty three ; and at Salem anni 

 hundred and twenty upon a mean 



ally, for seven year 



one 



The number of rainy -days in those cities was upon a 



88 



and at Salem 9 



an- 



•mean 122 ; at Cambridge ou 

 nually, for seven years. 



The number of foggy days in those cities Avas sixty sev- 

 en* at Cambridge sixteen; and at Salem, for seven years, 

 twenty one days annually. 



As to hygrometrical observations, we unluckily have none 



to 



pare with the Europ 



excel) 



nly those 



made by the illustrious Dr. Franklin, and communicated in 

 a letter to Mr. Nairne on hygrometers, published in the 

 2d. vol. of the Transactions of the American Philosophical 

 Society at Philadelphia; by which it appears, that the air- of 

 Philadelphia is 



drier 



than that of Great Britain 



but also than that of Passy, in France 

 to be direct. 



This evidence seems 



Our evaporation then is greater, than the European; our 



quantity of rain, much greater: we have more 



clear fair 

 days ; 



^ 



1^ 



