On tliCduft^-of Earthqu'ahes. "^ 345 



li finds" the leaft refiftance to its free pafiage. It appears, 

 then, that lliis roiitt nuid be that where the waters have not 

 flopped lip the pores of the earlh. It is for this reafon, pro- 

 bably, that volcanoes manifell themfeh'es at the fumTuits of 

 mountains. 



- 58. The crevices of volcanic mountains incline oftencr 

 from their centre towards the weft or the fouth than towards 

 the other fides. It is always towards ihofe parts that volca- 

 noes throw out their lava'. The reafon of this feem? to be 

 explained by the 31ft, 3ad, 33d, 34th, 35ih, and 36ih ob- 

 fervatio.ns, and in particular by the 37th and 3Sth. 



59. The molt violent volcanoes almoft always manifcft 

 thenifelvcs in the higheft mountains. 



60. It would appe;ir that the ice on the fumniits of thefe 

 mountains ought to fccure the earth found there from being 

 penetrated by the fnow water which the teniperature of the 

 air mav fometimes difTolve ; and, as this temperature afts 

 only on the furface of the fnow, the ice below ought to throw 

 off'that which is melted towards the fides where the declivity 

 is, and by thefe means prevent the water from penetrating 

 the earth' of the fummit to moiftcn that at the centre of the 

 mountain. 



61 . Volcanic mountains which are not very high, or which 

 are not fiiuated agreeably to the general pofition to which 

 fubterranean fires'^feem to proceed, have in general only 

 weak volcanoes, which often in the. end become extini:!:. 



62. Manv of the extinguifhcd craters have become lakes, 

 or refervoirs of rain wate'r, at the fummit of mountains; 

 fprin'is commonly manifell themfolves around their fides, 

 and ferve to fertilize the lands at their bottom, 



63. Hiftory makes mention of many lakes which have 

 been formed oy mountains being fwallowed up : all countries 

 fubjert to earthquakes have a grt-at'many of them, 



64. The earth has been fecn to fwell up fo as ahiioft to 

 form a hemifpherical mountain, and to burft fuddenly, with 

 a horrid cxplofion, and Icavenothing but a lake in the place. 



65. Many iflnnds have emerjred from the fea : lome of 

 thele have exifted for a long time, others have gradually dif- 

 appeared ; and fonie, in confcqtience of a continual imdula- 

 tion, occafioncd l)y lubfeirauvan fire, have difappeared after 

 being (lowly confimicd. 



It is here proper to obfervc, that a-1 thefe events take place 

 in continents or iflands the pofitions of which are analogous 

 to thof«; mentioned in the ill, 3d, and 9th obfervatious, 



Thoutrh this nu'iiioir is only a verv (hort cxtrart from a 

 manulcript lull during the troubles of the Cape, I think it 



my 



