^ ’■Scent . EAiTHftUAKEs. 147 
S''^eriments have shown, that, where the sub- 
occur, lie at a coasiderable 
**in '”sunih surmounted by a very deep and heavy 
Mil *’”^6 n Pleasure, more especially when they con- 
ftiu elastic gases, the effects of such fires 
« cin;. ^" greater, and more diversified, than where 
are absent. 
earth PU^’crftil and extraordinary of these 
reckoned. Tliey are unques- 
iw ®fc ngt dreadful of the phenomena of nature, 
of *h°se countries which, from the 
other • vicinity to volcanic mountains, 
f«lt .'’Olnrlv ®‘®'^ 3 r cause, have been considered as more 
ij| .. V SllKlrii^a- i.* *.1 .1 • . /T- . t . ^ . 
'S 
ha 
^'^riv e k* Aitivv uccii i,uii»iucicu as more 
’'t theg *3 .Joef to them, their effects having rft been 
Ml^'^ous i*j^*^*^ although not in so extensive and 
'L°®Srec. Their shocks, and the eruptions of 
|)fjh of ®ve been considered as modifications (rf tlie 
L ’’o common cause ; and where the agitation 
PC'* 'o ^ earthquake extends farther than there is 
, 10 soj -■ earthquake extends farther than there is 
’ H^^ted ” subten-aneous commotion, it is probably 
is cnv,'*^°'^Sh the earth nearly in the same manner as 
through the air. The different hypo- 
to .1, ^”''e been imagined on tliis subject may be 
''V'”c nat'^ following : 
ascribed earthquakes to water, 
apen’f others, again, to air; each of these 
Ml’ supposed to operate in the bowels of 
Mtfj they assert to abound every where with 
i!PW''^”^er caverns, veins, and canals, some filled 
hs e tilers with gaseous exhalations, and others 
'arious substances, such as nitre, sulphur, 
t.tt, ■^’s, WlioT'*'^®^- Each of these opinions has its 
Pt Paper written copiously on the subject. 
,'arious 
and 
j . wpej. written copiously on Uie subject. 
l" Philosopflical Transactions, 
suId 
earthquakes, as well as thunder and 
inflammable breath of the pyrites, a 
capable of spontaneous combustion; 
■'Miilb'quaV„ bad observed before him, he suppose! 
■ 'Xoodward thin 
more than subterraneout 
,^11 cq aru thinks, that the subterraneous 
• ’’’^ally raises the water from the abyss, or 
‘ ’n the centre of tlie earth, for the stjppljr 
a 2 
