Page:Journal of the Right Hon. Sir Joseph Banks.djvu/502

444 of Mr. Maskelyne, who was sent out to this island by the Royal Society for the purpose of observing the transit of Venus in the year [1761].

This small island, which is no more than twelve miles long and seven broad, is situated in a manner in the middle of the vast Atlantic Ocean, being 400 leagues distant from the coast of Africa and above 600 from that of America. It appears to be, or rather is, the summit of some immense mountain, which towering far above the level of the earth (in this part of the globe very much depressed) elevates itself even considerably above the surface of the sea, which covers its highest neighbours with a body of water even to this time unfathomable by the researches of mankind.

The higher parts of all countries have been observed almost without exception to be the seats of volcanoes, while the lower parts are much more seldom found to be so. Etna and Vesuvius have no land higher than themselves in their neighbourhood. Hecla is the highest hill in Iceland; in the highest parts of the Andes in South America volcanoes are frequent, and the Pike of Teneriffe is still on fire. These still continue to burn, but numberless others have been found to show evident marks of fire, although now extinct from the times of our earliest traditions.

That this has been the case with St. Helena, and that the great inequalities of the ground there have been originally caused by the sinking of the ground, easily appears to an observing eye, who compares the opposite ridges, which, though separated always by deep and sometimes by tolerably broad valleys, have such a perfect similarity in appearance as well as in direction as scarce leaves room for a doubt that they formerly made part of a much less uneven surface, and that this sinking in of the earth has been occasioned by subterraneous fires. The stones abundantly testify to this, as they universally show marks of having been at some time