24 



A COMPARISON BETWEEN THE CLIMATES OP 



the maxima are too high."* The minima are lower than at Mal- 

 vern ; consequently the situation of the gardens must be favourable 

 to terrestrial radiation. The mean minimum, also, is considerably 

 lower than the mean minimum at Malvern. 



In showery weather, when the clouds spread themselves out in 

 thin broad white sheets, a decline of temperature almost always en- 

 sues. This spreading out of clouds is frequently seen during, 

 or just after, thunder-storms; the massive-looking arched pillars of 

 vapour, which indicate the tension of electricity, always lose their 

 figure and spread over a larger space as the electric accumulation is 

 expended during the storm. 



TABLE II Mean height of the Barometer at Malvern and London, 



in 1834, 1835, and 1836. 



The result of these observations of the barometer has tended to 

 confirm the opinion that the movements of accurate barometers 

 within a moderate distance (100 miles) of each other, are nearly 

 simultaneous and equal, except when the mercury is rapidly rising 

 and falling, then some hours occasionally intervene in the progress 

 of the atmospheric oscillations. Still the annual mean difference 

 between two perfect instruments within the distance mentioned, 

 after the necessary corrections, will be a tolerably true indication of 

 the elevation of the one above the other. By referring to the ta- 

 ble it will be seen that the mean difference of two years between 

 the barometer in Malvern and that of the Royal Society, in Lon- 

 don, is .573, or something more than half an inch ; which would 

 give the elevation of the village of Great Malvern within a very 

 few feet of the height deduced by the barometrical measurement of 



Vide PfUlosophical Magazine, vol. 7? P- 355. 



