VOL. LI.] PHILOSOPHICAL TRANSACTIONS. 469 



The same was observed at Jamaica likewise. In the earthquake that destroyed 

 Port-Royal in \0g2, we are told, that " more houses were left standing at that 

 town than in all the island besides. It was so violent in other places that 

 people were violently 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 scarcely 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. lago, except a few low houses, built by the wary Spa- 

 niards. In Clarendon precinct the earth gaped, and spouted up with a prodi- 

 gious force great quantities of water into the air, 1 2 miles from the sea ; and 

 all over the island there were abundance of openings of the earth, many thous- 

 ands. 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 mountains the greater 

 the shake ; and that the cause thereof, whatever 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 great shakes continued, bellowed out prodigious loud noises and echoings. 



" Not far from Yallowes, a mountain, after having made several moves, over- 

 whelmed a. whole family, and a great part of a plantation lying a mile off; and 

 a large high mountain near Portmorant, near a day's journey over, is said to be 

 quite swallowed up. 



" In the blue mountains, whence came those dreadful roari;igs, may reasonably 

 be supposed to be many strange alterations of the like nature ; but those wild 

 desert places being very rarely, or never, visited by any body, we are yet ignorant 

 of what happened there ; but whereas they used to afford a find green prospect, 

 now one half part of them, at least, seem to be wholly deprived of their natural 

 verdure." 



Sect. vi. — Mr. M. has supposed that fires lying at the greatest depths generally 

 produce the most extensive earthquakes ; we must however except from this rule 

 those cases where the depths are very great : for, as the weight of 3 miles per- 

 pendicular of common earth is capable of absolutely repressing the vapour of 

 inflamed gunpowder, so we may well suppose that there may be a quantity of 

 earth sufficient to repress the vapour of water, and keep it within its original 

 limits, though ever so much heated. Now, whenever this is the case, it is ma- 

 nifest that it can produce no effect : or it may happen, that though the quan- 

 tity of earth may not be sufficient absolutely to repress the vapour, yet it may be 

 so o-reat, as to suffer it to expand but very little : in this case an earthquake arising 

 from it would be but of small extent ; the wave-like motion would be little or 

 none ; the vibratory motion would be felt every where ; arid the propagation of 

 the motion would be very quick. This last circumstance being almost the only 



