242 LOWEST TEMPERATURE OF JANUARY, 1838. 



side wall of my house, five feet above the ground. In one hour the mercury of 

 this thermometer had disappeared from the tube, which is graduated to eight de- 

 grees below zero. Some observations which I was making on the rale of cooling 

 within doors prevented me leaving this thermometer outside. Next morning at 

 eight o'clock the mercury of Dollond's thermometer was just rising from the 

 tube. I again put out Adie's thermometer, which had fallen to two degrees above 

 zero by nine o'clock, and it then commenced to rise again. From these observa- 

 tions, I am entitled to say, that in the country within fifteen miles of London, 

 the cold was below zero of Fahrenheit, and probably continued so for at least 

 twelve hours ; and that the temperature of four degrees below zero was even 

 exceeded in this parish of Thames Ditton. The circumstance of thermometers 

 sold by our first makers of instruments of this kind, for the purpose of meteor- 

 ological observation, not being graduated low enough to indicate the exact 

 temperature of this night, is strongly indicative of the unusual severity of the 

 cold. Indeed, from the facts stated, it is probable that on the night of the 19th 

 of January, we had here a lower temperature than has been recorded in the 

 vicinity of London. It may be fancied that the very low temperature is an 

 indirect evidence of some inaccuracy in the observations, or in the graduation of 

 the instruments. But in regard to the first supposition, I may add that the 

 instruments were examined at intervals for some hours, so that there could be no 

 mistake in reading the figures ; and the agreement between the two instruments, 

 made by different persons, both of whom are of high reputation, is presumptive 

 proof of accuracy ; beside which they have been compared with other thermome- 

 ters by the same makers, and have been tried in various ways during several 

 years in which they have been in my possession. A third themometer (a 

 minimum register, by Adie) also fell below zero, and became useless; but the 

 index-pin was left at zero, the oil having adhered to the tube and separated. 

 A farmer informed me that his thermometer fell to 14 degrees within doors. 

 Hence we must conclude, either that London was many degrees warmer than the 

 surrounding country on this night, or that the record at the Royal Society is 

 inaccurately kept. Probably both circumstances occurred ; at least no one can 

 look over the tables published in The Athenaeum without being convinced that 

 the minima are incorrectly given; the temperature at a fixed hour being some- 

 times entered as lower than the loicest degree for the whole twenty-four hours of 

 the same day. 



In driving into town, on the morning after nights of frost in spring, I have 

 frequently observed that the vegetation has suffered much more in this neigh- 

 bourhood than has been the case nearer to London, which is presumptive proof 

 of greater cold here ; and our crops are always a few days later than those of 

 Kent and Middlesex, in the parts near London. I will shortly send, for The 



