upon the Phenomena, of Earthquakes, 182 
2. That these concussions should owe their origin to some- 
thing ip the air, as it has sometimes been imagined, seems very 
ill to correspond with the phenomena. This, 1 apprehend, will 
sufficiently appear, as those phenomena are hereafter recounted ; 
nor does there appear to be any such certain and regular con- 
nexion between earthquakes and the state of the air, when they 
happen, as is supposed by those who hold this opinion. It is 
said, for instance, that earthquakes always happen in calm still 
weather: but that this js not always so, may be seen in an account 
of the earthquakes in Sicily of 1693*, where, we are told, “ the 
south winds have blown very much, which still have been im- 
petuous in the most sensible earthquakes, and the hike has hap- 
pened at other times.”’ 
3. Other examples to the same purpose we have in an account 
of the earthquakes that happened in New England in 1727 and 
1728; the author of which says, that he could neither observe 
any connexion between the weather and the earthquakes, nor 
any prognostic of them; for that they happened alike in all 
kinds of weather, at all times of the tides, and at all times of the 
moon f. 
ditional ones, in “‘ The History and Philosophy of Earthquakes,” (a work 
well worth the perusal of those who are desirous of being acquainted with 
this subject). The author of it has given us, besides the aforesaid facts, 
a very judicious abridyement of ten of the most considerable writers upon 
the subject. I have taken the greatest part of my authorities either from 
this author, or the Philesophical Transactions, that those-who wou!d wish 
to examine them may have an oppertunity of doing it the more easily: 
-some things only, which were not to be met with in these, and which yet 
were necessary to my purpose, I have been obliged to seek for elsewhere. 
* See Philos. Trans. No. 207; or vol. ii. p. 408.—Lowthorp’s Abridge- 
ment. 
+ See Philos. Trans. No. 409; or vol. vi. part ii. p. 02.—Eames’s Abridve- 
ment.—Tv these authorities we may add the opinion of Mons. Bertrand, 
who expresses himself, upon this occasion, in the following manner: “ Ari- 
stotle, Pliny, and Seneca, tell us, that earthquakes are preceded by a calm 
and serene air. This is, indeed, often the case, but not always. T don’t 
know, upon an examination of the whole, if there are not as many excep- 
tions to this rule, as examples that confirm it. Some authors again have 
thought, that they might look onadark sky, lightnings, and sudden storms, 
as the forerunners of earthquakes.” Then relating some instances of shocks 
that happened in calm and serene weather, he adds, “ On the other hand, 
it appears, from the examples which we have before related, that many 
earthquakes have bappened at the time of great rains, violent winds, and 
with a cloudy sky; so that one cannot find any certain prognostic of thew 
in the state uf the atmosphere.”—See Memoires Historiques et Physiques 
sur les Tremblemens de Terre, par Mons. Bertrand, a la Haye 1757. ‘This 
author, in these sensible memoirs, has oblived the public with a circum: 
stantial account of all the facts he could collect, relating to the earthquakes 
of Switzerland, or those of other places that seemed to be connected with 
them. The whole seems to be done with care and fidelity, aud without the 
Jeast attachment.to avy particular system, 
weet 7 4, If, 
