356 METEOROLOGICAL OBSERVATIONS. 



METEOROLOGICAL 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. 



PARTIAL FROST. The country people, who are abroad in 

 winter mornings long before sun-rise, 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, consi- 

 dering the small quantity of rain. Does not the warmth at 

 such times come from below ? The cold in still, severe sea- 

 sons, seems to come down from above : for the coming over 

 of a cloud in severe nights raises the thermometer 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 mois- 

 ture. 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. 



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 



