Some considerations on the causes of earthquakes. Which were read before the Royal Society, April 5, 1750 / By Stephen Hales.

  • Hales, Stephen, 1677-1761.
Date:
1750
Catalogue details

Licence: Public Domain Mark

Credit: Some considerations on the causes of earthquakes. Which were read before the Royal Society, April 5, 1750 / By Stephen Hales. Source: Wellcome Collection.

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    by the drying of the feveral horizontal Lay¬ ers of Earth $ and will alfo be confiderably the wider in long dry hot Seafons* which are ufually the preparatory Forerunners of Earthquakes. And the Explofion of the ful- phureous Vapours may probably widen them more* It is very obfervable that even Volcano’s* in the Opinion of Borelli and other Natura- lifts, began firft to kindle near the Surface and Top of the Mountains, and not by the fermenting of the Pyrites and fulphureous Vapours in the Caverns, in the lower Parts of the Mountain. Monf. de Buffon fays, that Earthquakes are mod frequent where there are Volcano’s, fulphureous Matter a- bounding mod there ; but that tho’ they continue burning long, yet they are not very exteniive. But that the other fort of Earthquakes, which are not caufed by a Volcano, extend often to a great Diftance. Thefe are much longer Eaft and Weft, than broad North and South ; and fhake a Zone of Earth with different Degrees of Force in C 2 different