EARTHQUAKE. 
bottom through their craters; this inter- 
fering with the operations of the fire, vast 
bodies of steam must ensue, tlian wliich no- 
thing can be more powerful and insinuating ; 
this rushing by the force of violent explo- 
sions through every aperture of the various 
stratas of the surrounding eartli, must occa- 
sion those horizontal and perpendicular 
movements and tremblings, so terrific to 
the inhabitants above ; besides, hot steams, 
impregnated with sulphurous vapours, often 
attend earthquakes. 
Homer, whose knowledge was extensive, 
seems to have been aware that the sea 
caused earthquakes, several instances of 
which might be quoted from the Iliad : 
“ But Neptune rising from the seas pro- 
found, 
The God whose earthquakes rock the 
solid ground.” Bookxiii. 1. 67. 
And in the xxth book, line 77. 
“Beneath, stem Neptune, shalves the 
solid ground ; 
The forests wave, the mountains nod 
around ; 
Through all their summits tremble Ida’s 
woods. 
And from their sources boil her hundred 
floods.” 
Indeed the sudden eruption of stones and 
calcined matter seem unquestionably the 
effect of water flying off in steam, and car- 
rying every loose object with it. The sea, 
or water of any great extent always indi- 
cates the commencement of an earthquake 
before it is otherwise perceived, this cir- 
cumstance doth not proceed from any cause 
peculiar to the component parts of the 
water, but merely from the motion of the 
earth under the bottom, which is not felt by 
a person on the adjacent shore, probably 
from its gliding steadily in one direction, 
and returning in the same manner; but 
water ever seeking a level will rise at the 
remotest influence from the land, as that 
inclines towards it, and then rush precipi- 
tately back to its previous level, as far as it 
can be attained, before another inclination 
of the earth prevents it. The sea is observ- 
ed to retire before the eruptions of Vesu- 
vius, which is evidently caused by the ris- 
ing of the earth during the first efforts of 
the- matter endeavouring to escape out of 
the mountain ; when that is discharged the 
water flows back again impetuously, plainly 
indicating that the earth has again sunk 
to its original place; the same effect was 
noticed at Lisbon, as far as related to the 
dreadful agitation of the sea, from wliich 
vessels received violent shocks at fifty 
leagues distance, indeed the effects of that 
earthquake, so fatal to the city above 
named in 1755, were felt throughout Eu- 
rope and America. 
Having detailed some of the probable 
causes of earthquakes, it will be proper to 
mention the indications of their approach 
in those countries were they are most pre- 
valent, which is in Mexico, Peru, Jamaica, 
and the neighbouring Islands ; Italy, parti- 
cularly in Sicily, Asia minor, and Portu- 
gal ; they are felt in almost every other 
country, but so slightly as seldom to occa- 
sion serious injui-y. Beginning near their 
visible causes, where they are necessarily 
most frequent, it may be observed that 
when a long interval has occurred from the 
last eruption of a volcano, there is just rea- 
son for alarm,- that the succeeding will be 
introduced by violent concussions of tlie 
earth. There are some phenomena which 
attend earthquakes of decided certainty, 
others may happen accidentally near the 
time of their approach, and be attributed 
erroneously to them ; such as very dry and 
hot seasons, which undoubtedly take place 
frequently where shocks are but little 
known, and dark atmospheres caused by 
unusual vapours; of the latter, many in- 
stances are recorded without the least cala- 
mity following, indeed the case of Lisbon 
is directly in point against this being univer- 
sally an indication of earthquake, for the 
morning of that dreadful day was particu- 
larly fine, and the sun shone with the ut- 
most brilliancy. Neither is the sudden ebb- 
ing and flowing of the sea, or rivers, always 
to be depended upon as the forerunner of 
convulsions of the earth, though it is uni- 
formly the consequence of them, as such 
effects have been observed without any 
assignable cause. Electrical phenomena 
sometimes attend them, in violent streams 
of lightening, the aurora borealis, meteors, 
&c. but as these are common appearances 
they afford no just cause of alarm if a trem- 
bling of the earth doth not very soon suc- 
ceed. 
If the clear water of deep wells suddenly 
becomes heated and impregnated with soil, 
and an nnusual stillness of the air prevails, 
and cattle evince great restlessness and 
terror, well founded apprehensions may be 
entertained of an approaching earthquake, 
which will commence -with slight trembling 
motion, perceivable in the most fleshy parts 
