16 FEDNOM YE. 07F„CANToO L&

O'er ſhining oceans ray volcanic light, Or hurl innocuous embers to the night. While with loud ſhouts to Etna Hecla calls,

And Andes anſwers from his beacon d walls;

Furl innocuous embers. 1. 152. The immediate cauſe of vol- canic eruptions is believed to be owing to the water of the ſea, or from lakes, or inundations, finding itſelf a paſſage into the ſubterraneous fires, which may lie at great depths. This muſt füſt produce by its coldneſs a condenſation of the vapour there exiſting, or a vacuum, and thus occaſion parts of the earth's cruſft or ſhell to be forced down by the preffure of the incum- bent atmoſphere. Afterwards the water being ſuddenly raiſed into ſteam produces all the explofive efeds of earthquakes. And by new acceflions of water during the intervals of the exploſions the repetition of the ſhocks is cauſed. Theſe circumſtances were hourly illuſtrated by the fountains of boiling water in Ice- land, in which the ſurface of the water in the boiling wells ſunk

down low before every new ebullition,

Beſides theſe eruptions occaſioned by the ſteam of water, there ſeems to be 2 perpetual efuſion of other vapours, more noxious and(as far as it.18 yet known) perhaps greatly more expanſile than water from the Volcanos in various parts of the world. As theſe Volcanos are ſuppoſed to be ſpiracula or breathing holes to the great ſubterraneous fires, it is probable that the eſcape of elaſtic vapours from them is the-cauſe, that the earth- quakes of modern days are of ſuch ſmall extent compared to thoſe of ancient times, oi which veitiges remain in every part'of the world, and on this account may be ſaid not only to be innocu- ous, but uſeful,

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Mi Orn Mit Hemd Amir ad 30 Nh 8 1 Be