rr 



8 



Dr. Holyoke's Estimate of the Excess of Heat and Cokl 



I 



the many 



o 



which have been published «f 



the deptli of 



which falls 



g 



number of places 



in Europe, and for a long course of years, it appears, that 



the med^im quantity of 



in that quarter of the glob 



scarcely equals, bul certainly does not exceed, 30 inches 

 from year to year. But in America, viz. at Ipswich-Itam- 

 let, by the observations of the Eev. Mr. Cutler, iipon a 



mean of five years (the last of which, viz. 1787, was rath- 



er a dry one) there fell inches 49. 472. And by Dr. Wil- 

 liam's observations at Cambridge, there fell in .1785, inches 



47. 61G. — And by the observations of the Rev. Mr. French 

 at Andover, there fell there, on a mean of the seven last 

 years, inches 51. 2. annually. 



The number of fair unclouded days, which happen in 

 the course of a year, Tor several years together, in any place. 



must also 



some indication of 



ph 



dry 



4 



of that country; for 



clouds 



3SS of the atmos- 

 formed from the 



moisture existing in the air, a freedom from them mf5 



dicate 

 Now ; 



deficiency of moisture : that is, the air must be drier 



appears 



from the Ephemerides Meteorolog 



Pal 



tinae, that the mean number of fair day;^ by observations 

 made in twenty different cities in different parts of Europe,* 

 amounted only to sixty three, or sixty four, and that the 

 same year at Cambridge there were one hundred and seven- 

 ty three such days. To which I may add, that by my own 

 observations at Salem, upon a mean of seven years, we had 



hundred and thirty fair days annually 



The 



* Viz. Those mentioned in 



annexed table. 



