METEOROLOGICAL OBSERVATIONS 373 



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 vapor. WHITE. 



THAW. Thaws are sometimes surprisingly quick, consid- 

 ering 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, 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 moist- 

 ure. But the true philosophy is, that the steam and vapors 

 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 2Oth. 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 north-east 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. 



REFLECTION OF FOG. When people walk in a deep white 

 fog by night with a lantern, if they will turn their backs to 

 the light, they will see their shades impressed on the fog in rude 

 gigantic proportions. This phenomenon seems not to have 

 been attended to, but implies the great density of the meteor 

 at that juncture. WHITE. 



HONEY-DEW. June 4th, 1783. Fast honey-dews this 



