Transactions of the London Horticultural Society. 477 



Rogers, Esq. Jun., Sevenoaks, Kent. The Hon. W. F. Strangways, Abbots- 

 bury, Dorchester, John Henry Vivian, Esq. M.P., Singleton, Swansea, 

 Glamorganshire. Joseph Walker, Esq., Calderstone, near Liverpool. William 

 Wells, Esq., Redleaf, Tonbridge, Kent. John Williams, Esq., Pitmaston, 

 near Worcester. Mr. John Wilson, Gardener to the Earl of Surrey, Work- 

 sop Manor, Nottinghamshire. Mr. Robert Wilson, Gardener to his Grace the 

 Duke of Norfolk, Arundel Castle, Sussex. 



" 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 hereafter 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 ^o.^^ 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 ten 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 

 instance, was not farther advanced in leaf on the 1st of May, in the past 

 season, than it generally is on the 1st of April. The general temperature of 

 April and May being thus low, and the nights frequently frosty throughout 

 both months, vegetation advanced but little, and only commenced under 

 favourable circumstances in June ; plants consequently made the greater por- 

 tion 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 lignification. 



" October was nearly 2° below the average of its temperature, and con- 

 sequently did not contribute its usual share towards maturing 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 temperature of the last sixteen days of the month was 46° ; 

 instead of the temperature which usually occurs at the winter solstice, this 

 corresponds with that generally experienced even after the vei-nal equinox. 

 The rise of temperature, above that of November, was also greater than what 

 takes place between March and April. The thermometer was seldom below 

 40° at night, and never at freezing. These circumstances all contributed to 

 bring on excitement in the fluids of plants, as was evidently manifested in the 

 production of young shoots by many species. On Christmas day the thermo- 

 meter in the shade stood at 54^°. 



" In the beginning of January the weather was slightly rainy, and so un- 

 usually warm, that the lowest temperature observed on the 2d of the month 

 was 41°, and for each of the four first days the thermometer marked 48° in 

 the day, the wind blowing from the S. and S.W. On the 5th the wind shifted 

 to the N.W. and the temperature began to fall, but up to the 7th the thermo- 

 meter did not sink below 27°. After this, winter may be said to have set in ; 

 the weather continued to increase in severity till the night between the 19th. 

 and 20th, when it arrived at its greatest intensity and the thermometer sank 

 in the morning of the 20th to — 4i°, the ground being scarcely covered with 

 snow. 



" In quoting the temperature throughout this paper, I have only taken the 

 observations made upon thermometers placed under ordinary circumstances. 

 But where the thermometer was so isolated, as to be cut off from the influ- 

 ence of the heat emitted by surrounding bodies, the temperature was in reality 

 much lower, as will be seen by observing the column, in the following table, in 

 which the observations upon the radiating thermometer are recorded. The 

 daily register of the weather during this period was as follows: — 



I I 3 



