[ 6 33 ] 
104. As the obfervations relating to the earthquake 
of the 1 ft of November 1755 are too grofs, it would 
be in vain to attempt, by any of the foregoing me- 
thods, to determine with any certainty the depth at 
which the caufe of it lay ; but, if I might be allowed 
to form a random guefs about it, I fhould fuppofe, 
(upon a comparifon of all circumftances) that it could 
not be much lefs than a mile, or a mile and half, and 
I think it is probable, it did not exceed three miles. 
CONCLUSION. 
105. Thus have I endeavoured to lhew how the 
principal phenomena of earthquakes may be pro- 
duced, by a caufe with which none, that I have feen, 
appear to me to be incompatible. As I have not 
knowingly mifreprefented any fadt, fo neither have I 
defignedly omitted any that appeared to affedt the main 
queftion ; but, that I might not unneceffarily fwell 
what had already much exceeded the limits at frit in- 
tended for it, I have omitted, 
106. Firft, Thofe minuter appearances, which 
almoft every reader would ealily account for, from 
what has been laid already, and which did not feem 
to lead to any thing farther : inch, for inftance, are 
the fudden flopping and gufhing out of fountains, oc- 
casioned by the opening or contracting of fhfures; the 
dizzinefs and ficknefs people feel, from the almofl 
imperceptible wave-like motion, &c. 
vapour. I don’t find, that this phenomenon, which is a common 
attendant on earthquakes, was obferved any-where, at the time of 
the earthquake of the iff of November 1755, except at Amfter- 
dam, where the mercury fubfided more than an inch. See Hift. 
and Philof. of Earthq. p. 309, 
107 . Se- 
I 
