334 Conjectures concerning the Cause, and Observations 
lowest of which exceeds the height of Riobamba by above two- 
thirds of a mile, and the highest by more than twice that quan- 
tity. Now, as the earthquakes have been more violent at the 
foot of these mountains, than in the lower lands, so they have 
been still more violent towards the tops of them: this is sufficiently 
manifest, from the many rents made in them and the rocks*, 
that have been broken off frem them, upon such occasions: but 
it appears still more manifestly, and beyond all dispute, in the 
‘bursting forth of voleanos, which are almost always at the very 
summit of the mountains +, where they are found. In these in- 
stances, the earth, stones, &c. which lay over the fire, are ge- 
nerally scattered by the violence of the vapour, that breaks its 
way through, to the distance of some miles round about. 
85. The great earthquake of the Ist of November 1755, was 
also more violent amongst the mountains, than at the city of 
Lisbon. We are told, that “ the mountains of Arrabida, Estrella, 
Julio, Marvan, and Cintra, being some of the largest in Portu- 
gal, were impetuously shaken, as it were, from their very foun- 
dations ; and most of them opened at their summits, split and 
rent in a wonderful manner, and huge masses of thein ‘were 
thrown down into the subjacent valleys t.”’ 
86. The same was observed at Jamaica likewise. In the earth- 
quake that destroyed Port-Royal in 1692,we are told, that ** more 
houses were left standing at that town than in all the island be- 
sides. It was so violent in other places, that people were vio- 
_ lently thrown down on the ground, where they lay with their 
legs and arms spread out, to prevent being tumbled about by the 
incredible motion of the earth. It scarce left a planter’s house 
or sugar-work standing all over the island: I think it left not a 
house standing at Passage Fort, and but one in all Liganee, and 
none in St. Iago, exeept a few low houses, built by the wary Spa- _ 
niards. In Clarendon precinct, the earth gaped, and spouted up, 
with a prodigious force, great quantities of water into the air, 
twelve miles from the sea; and all over the island, there were 
abundance of openings of the earth, many thousands. But in 
the mountains, are said to be the most violent shakes of all; and 
it is a generally received opinion, that the nearer to the moun- 
tains, the greater the shake; and that the cause thereof, what- 
ever it is, lies there. Indeed they are strangely torn and rent, 
especially the blue, and other highest mountains, which seem to 
be the greatest sufferers, and which, during the time that the 
* See d’Ulloa’s Voyage to Peru, part i. book vi. chap. 2. 
+ The only exceptions that I know of to this rule, are in those cases, 
where the highest part having an opening already, some fresh mouth opens 
itself in the side of the mountain. 
} See Hist. and Philos. of Earthq. p. 317. 
great 
a? 
