METEOROLOGICAL OBSERVATIONS. 303 



METEOEOLOGICAL OBSERVATIONS. 



BAROMETER. 



NOVEMBER 22, 1768. A remarkable fall of the barometer all over the 

 kingdom. At Selborne we had no wind, and not much rain ; only vast, 

 swagging, rock-like clouds appeared at a distance. WHITE. 



PAETIAL FROST. 



The country people, who are abroad in winter mornings long before 

 sunrise, talk much of hard frost in some spots, and none in others. The 

 reason of these partial frosts is obvious, for there are at such times 

 partial fogs about ; where the fog obtains, little or no frost appears ; 

 but where the air is clear, there it freezes hard. So the frost takes 

 place either on hill or in dale, wherever the air happens to be clearest 

 and freest from vapour. WHITE. 



THAW. 



Thaws are sometimes surprisingly quick, considering the small 

 quantity of rain. Does not the warmth at such times come from 

 below ? The cold in still, severe seasons seems to come down from 

 above ; for the coming over of a cloud in severe nights raises the ther- 

 mometer abroad at once full ten degrees. The first notices of thaws 

 often seem to appear in vaults, cellars, &c. 



If a frost happens, even when the ground is considerably dry, as soon 

 as a thaw takes place, the paths and fields are all in a batter. Country 

 people say that the frost draws moisture. But the true philosophy is, 

 that the steam and vapours continually ascending from the earth, are 

 bound in by the frost, and not suffered to escape till released by the 

 thaw. No wonder then that the surface is all in a float ; since the 

 quantity of moisture by evaporation that arises daily from every acre of 

 ground is astonishing. WHITE. 



FROZEN SLEET. 



January 20. Mr. H.'s man says that he caught this day in a lane 

 near Hackwood park, many rooks, which, attempting to fly, fell from 

 the trees with their wings frozen together by the sleet, that froze as it 

 fell. There were, he affirms, many dozen so disabled. WHITE. 



MIST, CALLED LONDON SMOKE. 



This is a blue mist which has somewhat the smell of coal smoke, and 

 as it always comes to us with a N.E. wind, is supposed to come from 



