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None can intelligently examine this remarkable region of country without a profound conviction that the entire valley of the Jordan from its highest source to the southern extremity of the Dead Sea, is, according to the opinion of these distinguished geologists cited above, a vast crevasse without a parallel. But does it end here? The immense cleft of the Arabah, which runs one hundred miles farther to the Ailanitic Gulf, the eastern arm of the Red Sea, is only a continuation of the same fissure, with the same geological features. Neither is this the end of the crevasse. As the waters of the Lake of Galilee and of the Dead Sea occupy a portion of the bed of this immense chasm, so those of the eastern arm of the Red Sea lie imbedded in a continuation of the same fissure, ninety or one hundred miles farther, where this gulf opens out into the Red Sea, at the southern extremity of the Peninsula of Sinai.

Thus, from the highest source of the Jordan to the Red Sea, a distance of three hundred and fifty miles, we have one uniform continuous chasm in the earth's surface, deep, dreary, desolate, mysterious, presenting throughout the same geological features, and evidently caused by the same convulsions of nature. It is a vast crevasse, without any parallel; a rent of stupendous dimensions in the surface of the earth, which opens a channel for the river Jordan and the bed of the Dead Sea, one hundred and fifty miles; beyond this, one hundred miles in a direct line, the chasm of the Arabah separates the waters of the Dead Sea from the Ailanitic Gulf, which sets back more than one hundred miles from the opening of this crevasse into the Red Sea.

But does this vast rent in the surface of the earth end even at the Red Sea? Or is the valley of this sea itself only a more tremendous expansion and extension of the same fissure, which, for more than a thousand miles, has by this immense chasm sundered from each other the kindred continents of Asia and Africa? We venture with diffidence to propound for the consideration of the learned the theory that these continents were once united by a broad isthmus

from the Straits of Bab-el-Mandeb, at the northwest angle of the Indian Ocean, to the Mediterranean Sea. We respectfully submit, for the consideration of the geologist, the theory that the entire valley of the Red Sea, the Ailanitic Gulf, the Arabah, the Dead Sea, and the Jordan are but continuous parts of one and the same immense fissure or crevasse, opened by some tremendous convulsion, or series of convulsions, from the Indian Ocean to the mountains of Lebanon.

To others better versed in these awful arcana of nature, we submit the inquiry by what particular agency this stupendous rent was opened up through the solid earth the distance of one thousand five hundred miles in length between Asia and Africa, and one hundred miles or more in width. Is this great crevasse the result of a long line of volcanic agencies, whose effects are so impressively manifest from the beginning to the end? The eminent authorities cited above distinctly intimate that this crevasse from Lebanon to the Red Sea, may be the result of "volcanic action." The tokens of such volcanic agency are equally clear and impressive along the whole line of the Red Sea itself; and as conclusively indicate that these tremendous internal agencies may have been alike effective in cleaving the earth asunder along the whole line of this crevasse. In this connection it may be pertinent to notice the indications of volcanic agencies which in various unmistakable forms are scattered along the entire line of this supposed crevasse, without advancing any theory as to the specific agency of volcanoes and earthquakes in producing the great phenomenon under consideration. Whatever may have been the cause, we cannot doubt that at some time, far back in the absorbing periods of the past, unrecorded, unknown, this enormous cleft was opened by some stupendous convulsion of nature, occasioned chiefly or in part by volcanic agencies. With this view, let us note some of the indications of these agencies along the line of the Jordan and of the Red Sea.

This sea itself occupies the bed of an immense longitudinal valley between parallel ranges of volcanic mountains.

Aden, the mart near the strait, is nestled in the crater of an extinct volcano. The islands that line the strait of Bab-elMandeb are all volcanic, as is also the adjacent coast, and the entire promontory. Several of the largest islands in the Red Sea, at distant intervals, are of volcanic origin. Niebuhr also describes "a mountain situated in the middle of the sea, said to have been formerly a volcano, and which is probably the burning island placed by Arrian and Ptolemy in these latitudes."

A long line of volcanic mountains runs parallel with the African shore of this sea. In these mountains porphyry and greenstone particularly abound. The adjacent desert in various places is strewn with vast, round basaltic boulders or balls, denominated by the author of Frost and Fire "volcanic bombs," which by some terrible volcanic enginery must have been shot out of the earth. This portion of the desert has not been sufficiently explored to indicate accurately its geological characteristics, but so far as is known they are eminently volcanic.

Upon the eastern shore of the sea are found coral reefs, many feet above the sea, in which they must have been formed. Coral also is said by Lieutenant Wellsted" to enter largely into the composition of some of the most elevated hills on the Arabian side of the sea. At Kahme near Beit el-Fakkih, basaltic columus were found by Niebuhr, like the giants causeway, "so uniformly regular that they might be mistaken for works of art." And he adds: "Piles of the same kind of rocks are found in many other parts of Arabia." On the way from Mocha to Sana, the capital of Yemen, "the rock which first occurs is porphyry, fractured so regularly into columns that the steep cliffs sometimes present the appearance of organ pipes; trap-rocks with basalt occurred, and at Sana the common building stone is lava. Mount Saben, likewise, is an immense mass of trachyte and other volcanic rocks." Ali Bey also in going from Djedda, the port of Mecca, to that city, passed "between some volcanic mountains covered with black lava." This traveller and

Niebuhr both report mines of native sulphur in the same region. Mineral salt is also a production of the country, "still worked near Loheia and several other places." At a place called Jedeida travellers also report seven groups of volcanic hills. At Medina "a layer of volcanic rock also occurs, and on the Hedjaz, the route of pilgrims to Mecca, hot springs are reported "at almost every station."

The entire Sinaitic group presents the most impressive indications of the terrible convulsions by which its labyrinth of mountain heights has been rent and torn since its first upheaval. From the summit of Mount Serbal, as from a watch-tower in high heaven, one looks down upon a perfect sea of mountain ridges, often precipitous, always intensely steep, and culminating in a sharp edge at the height of two, three, or four thousand feet from their base. The entire lines of these mountains is seen to have been rent transversely by clefts from the base to the summit, filled with injections of basaltic rocks, striping the mountain on each side with black bands. The whole assemblage is a perfect ganglion of ridges thrown up in wild confusion, with its strata dislocated, disjointed, dipping in all directions and at every angle from horizontal to perpendicular. The mountains of Sinai form no system, no regular ranges like the Alps, the Appenines, Pyrenees, or the mountains of America.

Jebel Hummâm and the hot springs at its base, forty-five miles below Suez, and the hot springs at Tur, near the southern extremity of the western arm of the Red Sea, are significant indications of the fires that are still burning within. On the western shore of the Ailanitic Gulf, nine miles from the southern angle of the peninsula, Burckhardt reports the existence of " volcanic rocks." "For a distance of about two miles the hills presented perpendicular cliffs, formed in half circles, none of them being more than sixty or eighty feet in height; in other places there was an appearance of volcanic craters." The disruptions, faults, and dykes along the mountain heights on the whole line of this gulf, with the frequent occurrence of porphyry and greenstone, and

occasionally of chalk, bear unequivocal evidence of volcanic agency. These disruptions open passes singularly wild, between perpendicular bulwarks of rocks, which frequently compress the passage into a gateway ten and twelve feet in width, leading from the platform of the desert down to the shore of the gulf. Toward the northern extremity of the gulf for several miles, a line of basaltic cliffs advances quite up to the sea, leaving only a narrow pathway for the camel; then jutting into the sea, compelling us to pass them by a toilsome detour around and over their heights. Burckhardt, with his customary accuracy, has noted this geological formation. "We followed a range of black basaltic cliffs, into which the sea has worked several creeks, appearing like so many small lakes with narrow openings toward the sea. They are full of fish and shells."

The indications of similar convulsions again become exceedingly impressive about the base of Mount Hor, at Petra, in the mountains of Edom. In addition to the famous fissure which opens a wild pass from the high plains on the east down to the rocky abyss occupied by the old city itself, one as wild and extensive runs up towards the rock-hewn temple known as ed-Deir, the convent. And an unexplored fissure again breaks down through the mountains several miles to the valley of the Arabah. None can mistake the geological indications of this region. Further north, in the mountains of Edom, fifteen or twenty miles southeast of the Dead Sea, the indications of volcanic agency become more marked. A group of four mountain heights is reported by Burckhardt and by Irby and Mangles, composed entirely of basaltic rocks, lava, and other remains of extinct volcanoes. Similar volcanic indications are found in Wady Ahsy, east of the southern extremity of the Dead Sea, and again at Kerek and on the river Arnon. Above this river, on the shore of the sea, Lieutenant Lynch reports "huge black boulders lying confusedly on the shore, which proved to be trap interspersed with tufa. The whole mountain, from base to summit appeared to be one black mass of scoriae and

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