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ance, I can mofl readily and willingly afk pardon for 
the trouble, which I have given, and dehfl; from 
giving any for the future. I am, 
S I R, 
Your moft obedient humble fervant. 
Hen. Eeles. 
7^ the Royal Society, 
LETTER II. 
Gentlemen, Lifmore (in Ireland), Nov. 25, 1754. 
great honour you have 
. X done me, in accepting my 
letter concerning the caufe of thunder, has embol- 
dened me to proceed in part of what I therein pro- 
pofed, vtz, to endeavour to fhew, that the fire, which 
IS made apparent by eledlrical experiments, is the 
principal caule of the afcent of vapour and exhala- 
tion ; and that the lower part of oUr atmofphere is, 
by that means, kept more homogeneal than is gene* 
rally fuppofed, and fitter for refpiration, vifion, Gfc. 
and that clouds of heterogeneous matter are kept 
^fpended, at their ufual height, merely by this fire. 
To which I have added fomething concerning the 
caufe of the winds, and to explain the general phe- 
nomena of the weather and barometer. 
But as I mufi: now contradid fome generally re- 
ceived opinions, it may be thought decent to make 
fome apology for offering my own. But I fhall not 
take 
