148 BOARD OF AGRICULTURE. 



or than is now customary to collect and preserve on all scientific 

 topics. The science of meteorology, or the observance of the 

 weather, in the largest sense of the words, is even now in its 

 infancy, and the instruments necessary to carrying on such 

 observations witli precision, are of very modern date. The 

 thermometer was little used in this country, or even in older 

 countries, previous to the last century, and all instruments of 

 this kind employed in the early part of that century were very 

 imperfect. Till after the year 1750, the only thermometer 

 used in New England was Hawksbee's. Not a single specimen 

 of this instrument is now known to exist. There is good reason, 

 however, to believe that it was much less accurate than any 

 thermometer now employed. During more than half a century, 

 however, tliat of Fahrenheit has been in general use throughout 

 New England at least, and we possess an exact register of ob- 

 servations made witli it during more than forty years on one 

 spot, and by one individual, the venerable Dr. Holyoke, of Salem. 

 A particular account of this register may be found in a valuable 

 paper l)y the late Dr. E. Hale, in the Transactions of the 

 American Academy, Vol. 1, New Series. The temperature of 

 each day was thrice noted at the same hours during the whole 

 period. As a comparative statement, therefore, of the earlier 

 and later portions of that period, it is of singular value. No 

 conclusion can be drawn from it, as Dr Hale has clearly shown, 

 favoring, in the least, the popular impression respecting the 

 amelioration of our climate. On the contrary, it seems evident 

 from Dr. Hale's Essay, that from the year 1786 to the year 

 1829, the climate of the vicinity of Boston has continued essen- 

 tially the same. It should be recollected that in no previous 

 period, of equal length, were the changes greater or more ex- 

 tensive in the face of our country, as well as the condition of its 

 inliabitants, or greater inroads made on our ancient forests. 



There is another interesting as well as important mode 

 of procuring light upon this question of change of climate, viz. : 

 by observing for years in succession the periodical changes in 

 the vegetation of our trees and shrubs. It has been observed 

 by the late Mr. Lowell, that " had there been precise records 

 kept of the date of flowering of trees in certain specific loca- 

 tions fi'Dm the first settlement of the country, very much would 



