326 Conjectures concerning the Cause, and Observations 
68. We are told, that two or three days before an earthquake * 
in New England, the waters of some wells were rendered muddy, 
and stank intolerably : why might not this be occasioned by the 
waters contained in the spaces before described, which, being 
impregnated with sulphureous steams, were driven up, and mixed 
with the waters of the springs ! ? At least, there can be no doubt, 
by whatsoever means it was brought about, that this phanome- 
non was owing to the same cause, already" beginning to exert 
itself, which afterwards gave rise to the succeeding earthquake, 
69. Something like this happened before the great Lisbon 
earthquake ¢ of 1755. We are told, that at Colares, about 
twenty miles from thence, “ in the afternoon preceding the Ist 
of Nov ember, the water of a fountain was greatly decreased : on 
the morning of the Ist of November, it ran very muddy, and af- 
ter the earthquake, it returned to its usual state, both in quantity 
and clearness.” The same author says, a little lower, ‘ in the 
afternoon of the 24th, I was much apprehensive, that the fol- 
lowing days we should have another great earthquake ; for I 
observed the same prognostics as in the afternoon of the 31st of 
October; thatis,” &c. ‘And I further observed, that the water 
of a fountain began to be disturbed to such a degree, that in the 
night it ran of a yellow clay colour; and from midnight to the 
morning of the 25th, I felt five shocks, one of which seemed to 
me as violent as that of the 11th of December.” 
70. But the most extraordinary appearance of any that pre- 
ceded this earthquake, was that of the agitation of the waters 
of Lochness {, and some others of the lochs in Scotland, about 
halfan hour before any motion was felt at Lisbon, notwithstand- 
ing the cause of all tiese great effects could not lie far from 
thence, and, I think, certainly lay to the south of Oporto. Ner 
is it probable, that there should be any mistake in the time, not 
only because the difference is too great, as»well as the concur- 
rent testimonies too many, to admit of such a solution ; but be- 
cause they mention another greater agitation, that happened 
* See Philos. Trans. No. 437, or Martyn’s Abridgem. vol. viii. p. 689. 
+ See Philos. Trans. vol. xlix. p. 416 and 417; or Hist. and Philos. of 
Earthq. p. 313. 
+ See Philos. Trans. vol. xlix.—or Hist. and Philos. of Harthq. art. Loch- 
ness, Lochlomond, &c. Tne same thing also seems to have taken place in 
Switzerland; for Mons. Bertrand says, that all the agitations of the waters 
in the lakes there, which were observed on the lst of November 1755, hap- 
pened between nine and ten in the morning; and particularly at lake Le- 
man, he says, the agitation happened just before ten; which, allowing for 
the difference of longitude, must have been just before nine at Lisbon; and, 
consequently, if there is no mistake in the times, all these agitations pre- 
ceded the earthquake, at this last place, by near three ao of an hour. 
[See Memoires sur les Tremblemens de Terre, p. 107 & 105.) 
about 
