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Show 248 THE ATMOSPHERE TRANQUIL. brought all the elements into play. Its smallness is indeed an advantage to those who study it, because it comes as near to being an experimer.~ in the making of islands by the action of fire as it is possible for any thing in nature to come. The internal action, when deep below the water, was sensible only in the motion communicated by the quaking earth to the water over it; and as the heat was only one degree above the common temperature at twelve yards from the island, one can hardly suppose that any smoke or even steam could come to the surface, or be produced, until the solid matter had risen very nearly to that. On the 28th of June, when Sir Pulteney Malcolm and his companions felt the shocks, the action had begun, but was going on quietly under the water. It may be indeed that there is always an action under that part of the Mediterranean, as shoals are laid down near the place in some of the charts; and the Maltese have traditions about a former island there. But Swinburne found no bottom with a line of eighty fathoms, till he came within twenty yards of the is}and, and there as has been said, it was eighteen fathoms, or one hundred and eight feet. That is an exceedingly abrupt slope, and would meet the bottom of one hundred and thirty fathoms deep, at little more than one-twelfth part of a mile, if we suppose the slope uniform. The rapidity of the slope, and the depth of the sounding are not very consistent with the supposition that a shoal in any way tended to the formation of the island, though it is true, that with the same external action, the bottom would rise more readily in shallow water than in deep. The island was subsequently visited by various persons, and the nature of its materials examined. Ashes, a substance resembling cake, scoria of iron, and burnt clay were the chief ones ; and there were not many of the substances that are usually discharged in the eruption of volcanoes. It should SABRINA. seem that only the common matters at the bottom of the sea came to. the surface, even when the walls of the crater attamed an elevation of nearly two h~ndred fe_et ; for t_he layers formed by the succesSive eruptwns, wh1ch could easily be distinguished by the salt th3;t was left ~h~n they evaporated the water, were fnable and yieldmg to the action of the waves. It seems to be not an unusual occurrence in what may be called volcanic seas, for small island's to ri~e up m that manner, and afterward to disappear, probably by the mere action of the water. That was the case with the island of Sabrina, which made its appearance off the Azores in 1811, and attained nearly the s~me dimensions as the one in question. It has no'Y disappeared and there are eighty fathoms of water m the place where it stood. As those in .. stances are well authenticated, and as others have been mentioned, i~ is by no me~ns unlikely that they occur frequently m the sea w1thout producing any appearance at the surface. It would be contrary to the g~neral economy of nature, in which there is no thmg or power out of the connexion, to suppose that those depths of the sea, which we may conclude are too far from the action of the sun and atmosphere. for supporting life, lie idle. They are very ~xtens1ve, and the power of water pressure in them IS vast. It therefore agrees with the analogy . ~f nature, as well as with the observed facts, that !n the~ are placed the grand laboratories of nature, 1n .whiCh new lands are prepared; and that the actwn of those smaller submarine volcanoes which shoot up their columns of charred and granul~r matter, to be st~ewed over. the bed of the ocean by the · currents of ~ts waters, IS the process by which the str~ta are mixed and tempered, so as to fit them for theu purposes. ~he following cut will give some idea of that . achon: |