METEOROLOGICAL OBSERVATIONS. 363 



THAW. 



Thaws are sometimes surprisingly quick, considering the 

 small quantity of rain. Does not the warmth at such 

 times come from below 1 The cold in still, severe seasons 

 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, etc. 



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 suff'ered 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 isfastonishing. — "White. 



FROZEN SLEET. 



January 20th. 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 London. It has a strong smell, 

 and is supposed to occasion blights. When such mists 

 appear they are usually followed by dry weather. — White. 



