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I V. Ohfervations on the Heat of the Grotmd 
on Mount Vefuvius : By John Howard, 
Efq\ F, R, S, 
Read Jan. 17, BEG leave to lay before this Society, 
1771- fome obfervations which I made laff 
June, on the heat of the ground on mount Vefuvius, 
near Naples. 
On my afeending the mountain, I often immerged 
the bulb of a thermometer in the ground, but found 
no fenfible heat for fome time : the iirll: riling in 
my thermometer, was 114°; every two or three 
minutes, I obferved the inflrument, till I gained the 
fummit. At thofe times, I found it riling to 122°, 137% 
147°, 164°, and 172°: on the top, in two places, 
where I made the obfervations, in tlie interllices be- 
twixt the hard lava, itw'as2i8°. Such a degree of 
heat, after I had 'overcome the inconvenience of the 
exhalations, raifed n*y curiolity to know if there was 
a flill greater degree of heat in the mouth of the faid 
mountain. Accordingly, I made a fmall defeent, 
and, by two obfervations I carefully and attentively- 
made, my thermometer both times flood at 
240°. 
John Howard. 
P. S. It 
