224 THE NATUEAL HISTOKY 



On the 3d of January Benjamin Martin's thermometer within 

 doors, in a close parlour where there was no fire, fell in the night 

 to 20, and on the 4th to 18, and the 7th to 17 J, a degree of cold 

 which the owner never since saw in the same situation ; and he 

 regrets much that he was not able at that juncture to attend his 

 instrument abroad. All this time the wind continued north and 

 north-east ; and yet on the 8th roost-cocks, which had been silent, 

 began to sound their clarions, and crows to clamour, as prognostic 

 of milder weather ; and, moreover, moles began to heave and 

 work, and a manifest thaw took place. From the latter circum- 

 stance we may conclude that thaws often originate under ground 

 from warm vapours which arise ; ^ else how should subterraneous 

 animals receive such early intimations of their approach ? More- 

 over, we have often observed that cold seems to descend from 

 above ; ^ for, when a thermometer hangs abroad in a frosty night, 

 the intervention of a cloud shall immediately raise the mercury 

 ten degrees ; and a clear sky shall again compel it to descend to 

 it's former gage. 



And here it may be proper to observe, on what has been said 

 above, that though frosts advance to their utmost severity by 

 somewhat of a regular gradation, yet thaws do not usually come 

 on by as regular a declension of cold ; but often take place 

 immediately from intense freezing ; as men in sickness often 

 mend at once from a paroxysm. 



To the great credit of Portugal laurels and American junipers, 

 be it remembered that they remained untouched amidst the 

 general havock : hence men should learn to ornament chiefly 

 with such trees as are able to withstand accidental severities, 

 and not subject themselves to the vexation of a loss which may 

 befall them once perhaps in ten years, yet may hardly be re- 

 covered through the whole course of their lives. 



As it appeared afterwards the ilexes were much injured, the 

 cypresses were half destroyed, the arbutuses lingered on, but 

 never recovered ; and the bays, laurustines, and laurels, were 

 killed to the ground ; and the very wild hollies, in hot aspects, 

 were so much affected that they cast all their leaves. 



^ [This notion was perhaps put into White's mind by some remarks in Hales' 

 Statical Essays, e.g. , vol. ii. , p. 360. It is almost needless to point out that 

 changes of weather arise not in the earth, but in the atmosphere, as the power of 

 prediction by observation of the barometer implies. ] 



2 [We now explain the fact which White goes on to relate by the radiation of 

 heat into space.] 



