30 



A HISTORY OF 



rible roarings of the wind, rushing through 

 the volcano, still louder than the former 

 rumblings in its bowels. At last all was 

 quiet, neither fire nor smoke to be seen, nor 

 noise to be heard; till, in the ensuing year, 

 the flames again appeared with recruited vio- 

 lence, forcing their passage through several 

 other parts of the mountain, so that in clear 

 nights the flames being reflected by the trans- 

 parent ice, formed an awfully magnificent 

 illumination." 



Such is the appearance and the effect of those 

 lires which proceed from the more inward 

 recesses of the earth : for that they generally 

 come from deeper regions than man has 

 hitherto explored, I cannot avoid thinking, 

 contrary to the opinion of Mr. Buffbn, who 

 supposes them rooted but a very little way be- 

 low the bed ofthe mountain. "We can never sup- 

 pose," says this great naturalist, "that these 

 substances are ejected from any great distance 

 below, if we only consider the great force 

 already required to fling them up to such 

 vast heights above the mouth ofthe mountain ; 

 if we consider the substances thrown up, 

 which we shall find upon inspection to be the 

 same with those of the mountain below ; if we 

 take into our consideration, that air is always 

 necessary to keep up the flame ; but, most of 

 all, if we attend to one circumstance, which 

 is, that if these substances were exploded 

 from a vast depth below, the same force re- 

 quired to shoot them up so high, would act 

 against the sides of the voJcano, and tear the 

 whole mountain in pieces." To all this spe- 



cious reasoning, particular answers might be 

 easily given ; as, that the length of the funnel 

 increases the force of the explosion ; that the 

 sides of the funnel are actually often burst 

 with the great violence of the flame ; that air 

 may be supposed at depths at least as far as 

 the perpendicular fissures descend. But the 

 best answer is a well-known fact ; namely, 

 that the quantity of matter discharged from 

 ./Etna alone, is supposed, upon a moderate 

 computation, to exceed twenty times the 

 original bulk ofthe mountain." The greatest 

 part of Sicily seems covered with its erup- 

 tions. 



The inhabitants of Catanea have found, 

 at the distance of several miles, streets and 

 houses sixty feet deep, overwhelmed by the 

 lava or matter it has discharged. But what 

 is still more remarkable, the walls of these 

 very houses have been built of materials evi- 

 dently thrown up by the mountain. The in- 

 ference from all this is very obvious ; that the 

 matter thus exploded cannot belong to the 

 mountain itself, otherwise it would have been 

 quickly consumed ; it cannot be derived from 

 moderate depths, since its amazing quantity 

 evinces, that all the places near the bottom 

 must have long since been exhausted; nor 

 can it have an extensive, and, if I may so call 

 it, a superficial spread, for then the country 

 round would be quickly undermined ; it must, 

 therefore, be supplied from the deeper regions 

 ofthe earth ; those undiscovered tracts where 

 the Deity performs his wonders in solitude, 

 satisfied with self-approbation ! 



CHAPTER X. 



OF EARTHQUAKES. 



HAVING given the theory of volcanoes, we 

 have in some measure given also that of 

 earthquakes. They both seem to proceed 

 from the same cause, only with this differ- 

 ence, that the fury of the volcano is spent in 

 the eruption; that of an earthquake spreads 



Kircher, Mund. Subt. vol. i. p. 202. 



wider, and acts more fatally by being confin- 

 ed. The volcano only affrights a province ; 

 earthquakes have laid whole kingdoms in 

 ruin. 



Philosophers'* have taken some pains to dis- 

 tinguish between the various kinds of earth- 



b Aristotle, Agricola, Buffon. 



