^i8 JAMAICA. 



No earthquake perhaps ever happens without an explofion or erup- 

 tion fomewhere or other ; but, where fuch explofion happen?, its etfctts 

 are always the moft deftru6tiv"e; and the injury decreales in proportion 

 to the fquares of the diftances from that part. 



At what diltance from the eruption the efFefls are fo far weakened, 

 as to caufe no damage to buildings, has not yet been decided. The pul- 

 fation, or ftroke, we know, may be communicated through a line of fome 

 thoufand miles in length ; thus the great earthquake at Lifbon, in 1755, 

 caufed fome unufual agitation of the water to be obferved at Barbadoes. 

 Ships, at 180 miles diftance at fea, felt the fhock in the fame manner as 

 if they had ftruck upon a rock ; but I am apt to think, that the etfefts 

 are rarely fatal to ilrong buildings at the diftance of 50 miles, unlefs 

 they lie on the fea-coaft, or arm of the fea, whofe water freely condudls 

 the fhock. 



Rivers are likewife conduftors, and the buildings fituated on their 

 banks are more feverely affefted than others which are remote from 

 them. 



On the 9th of November, 1761, the day cloudy and fultry, ther- 

 mometer, at ten o'clock A.M. j^ deg. the Southern horizon looked 

 extremely bLck, and a prodigious fwell tumbled into Kingfton har- 

 bour, which raifcd the water 2 | feet above the wharfs. On this day 

 happened an earthquake and ftorm at Carthagena, diftant about 435 

 miles, which did fome damage to the town, and choaked up the entrance 

 of their port with fand. The next day the wind at Jamaica was S. E. 

 vcrv fqually, attended with hard rain and thunder. On the nth, a 

 biitk North fet in. 



In 1 766 (June), when a violent earthquake happened at St. Jago in 

 Cuba (dillance about 95 miles), where it occafioned vafl mifchief, the 

 unJulatioii was felt the fame night at Jamaica, tending from North to 

 South, and fo (Irong, that it flopped the pendulum of every clock in the 

 ifland, but threw down no building. It was ftlt here between 1 1 and 

 12 at night. The evening was remarkably ferene, the Iky perfedly 

 clear, and the air unulually clofe. Some perfons, who were abroad, 

 obferved feveral ftreams of light, or ignited vapour to the Northwards, 

 darting up to a confiderable height, immediately before they perceived 

 the tremor. A fimilar phenomenon was obferved juft before the great 

 earthquake in Sicily (1693). Some country people, who were travel- 

 ing, faw a great flame, or light, fo bright, that they took it for real 

 fire; and, whilft they were gazing at it, the (hock began. I remember 

 likewife, that, whilft I was fitting at table after diimer one dav, the air 

 uncommonly fultry, the liOufe feemcd to be ftruck on a ludden as with 

 an eleflrical fiiock ; and, at the fame inllant I heard a rumbling noiie, 

 7 and 



