228 Observations upon the effects of Frost, 



I have also occasionally availed myself of such published accounts 

 as have appeared most worthy of notice. 



In order that the conclusions to be drawn from the facts here- 

 after noticed should possess their proper value, it is necessary in 

 the first place to explain the state of the weather, previously 

 to the occurrence of the frost itself, and during its continuance. 

 For this purpose the observations made in the garden of the 

 Society by Mr. Thompson, and a few derived from other sources, 

 will convey a sufficiently correct idea for the principal part of 

 England. 



The month of April, 1837, was perhaps the coldest and at 

 the same time the most sunless ever remembered. It was 7° Fahr. 

 below the mean of the same month for 10 preceding years ; and 

 the temperature of May following was 6° below the average. In 

 the latter month, the appearance of vegetation was like what it 

 generally presents a month earlier ; the common hawthorn, for in- 

 stance, was not farther advanced in leaf on the first of May, in 

 the past season, than it generally is on the first of April. The 

 general temperature of April and May being thus low, and the 

 nights frequently frosty throughout both months, vegetation ad- 

 vanced but little, and only commenced under favourable circum- 

 stances in June ; plants consequently made the greater portion 

 of their growth after Midsummer, and during the Autumn, at 

 which season the shortness of the days, and an unusual deficiency 

 of sun heat, were insufficient to enable them to complete the 

 process of lignincation. 



October was nearly 2° below the average of its temperature, 

 and consequently did not contribute its usual share towards ma- 

 turing the wood of the season. November was fully 3° below the 

 mean. December was seasonable during the first fortnight ; but a 

 most remarkable change took place after the 15th. The mean 



