the Variation of Local Heat. 433 
tions : to thofe who make them, the refult of thefe experiments 
may be of fome ufe. If convenient opportunity offered, I 
fhould be glad, by the affiftance of friends, to try the local 
difference of heat and cold in more diftant, as well as more 
elevated, fituations. 
By experiments of this kind it may poffibly in fome mea- 
fure be found, how far evaporations from the earth, at certain 
times, or vapours afcending, deicending, or meeting, in dif 
ferent parts of the atmofphere, may increafe or diminifh the _ 
heat of the air in thofe places: or whether different degrees 
of heat and cold (fubje&t however to change) may not be found 
in different ftrata of air, or vapour, floating in different parts 
of the atmofphere; or in what degree and proportion, the cold 
increafes at different altitudes and in different feafons of the 
year: whether the cold, which is known to be very intenfe in 
the fummer time on the tops of high mountains, receives a 
proportional increafe, or be not lefs fubject to variety by the 
return of winter and fummer, night and day, than what we 
experience in the plains below. 
March 10, 1784. JAMES SIX. 
Vox. LXXIV. Lil TABLE 
