ey are aborg 
XX. Experiments to inveftigate the Variation of Local Heat. 
By James Six, E/y.; communicated by the Rev. Francis. 
$Vollation, LiBp ho wos: 
Read June ro, 1784. 
EING defirous of inveftigating the variation of local 
heat, I made the following experiments. Bd 
_ On the 4th of September, 1783, I placed thermometers im: 
three different ftations; one on the top of the high tower of 
Canterbury Cathedral, about 220 feet from the ground; ano-- 
ther at the bottom of the fame tower, at about 110 feet;. 
and a third in my own garden*, not more than fix feet from 
the ground. They were all carefully expofed to the open air 
in a fhady northern afpect ; the loweft was as little liable to be 
affected by the refleGtion of the fun’s rays as the elevation 
would permit, the fecond ftill lefs, and the higheft not at all. 
They continued unremoved in their feveral places, where I 
vifited them. daily for the {pace of three weeks, and minuted 
down the greateft degree of heat and cold that. happened each 
day and night in their refpective ftations +. 
* This garden is fituate not far from the Cathedral, at. the extremity of the 
buildings on the north fide of the city. 
+ The thermometers here made ufe of were conftructed to fhew the greateft 
degree of heat and cold which happened in the obferver’s abfence (defcribed Phil. 
Trani, vol, LXXII. part J.), which rendered them particularly convenient on this 
oceafion, They had hung together for fome time, and feldom differed half a 
degree from each other. 
By 


