the earth at its fountain, and then, after tumbling and foaming for a short distance over its rocky bed, it descends again into the ground, disappearing as suddenly and mysteriously as it came into being.
The plain which this evanescent stream thus gave up its life to fertilize, was all under cultivation at the time that Robinson visited it, being divided into gardens, which belonged to a certain tribe of wandering Arabs. This tribe were, however, not now encamped here, but had gone away to a tract of ground belonging to them in another part of the country, having left only a few sentinels to watch the fruits that were growing in the gardens. Robinson and his party went across the plain, and finally came to the margin of the sea, approaching it at last over a bank of pebbles which lined the shore, and formed a sort of ridge of sand and shingle, six or eight feet higher than the level of the water. The slope of these pebbles, on the seaward side, was covered with saline incrustations.
The water had a greenish hue, and its surface was very brilliant. To the taste, the travelers found it intensely and intolerably salt, and far more nauseous than the waters of the ocean. The great quantity of saline matter, which it contains, makes it very dense, and, of course, very buoyant in respect to bodies floating in it. This property of the sea has been observed and commented upon by visitors in every age. Swimmers, and those who can not swim, as an ancient writer expressed it, are borne up by it alike. Robinson himself bathed in the sea, and though, as he says, he had never learned to swim, he found, that in this water he could sit, stand, lie, or float in any position without difficulty. The bottom was of clean sand and gravel, and the bathers found that the water shoaled very gradually as they receded from the shore, so that they were obliged to wade out many rods before it reached their shoulders. Its great density produced a peculiar effect in respect to the appearance that it presented to the eye, adding greatly to its brilliancy, and imparting a certain pearly richness and beauty to its reflections. The objects seen through it on the bottom appeared as if seen through oil.
MEASUREMENTS
After having spent some time in noting these general phenomena, Robinson, finding that the day was wearing away, called the attention of his party to the less entertaining but more important work of making the necessary scientific measurements and observations. He laid off a base line on the shore, fifteen hundred feet in length; and from the extremities of it, by means of a large and accurate compass, which he carried with him in all his travels for this express purpose, he took the bearings of all the principal points and headlands which could be seen around the sea, as well as of every mountain in view. By this means he secured the data for making an exact map of the sea, at least so far as these leading points are concerned; for, by the application of certain principles of trigonometry, it is very easy to ascertain the precise situation of any object whatever, provided its precise bearing from each of two separate stations, and also the precise distance between the two stations is known. Accordingly, by establishing two stations on the plain, and measuring the distance between them, and then taking the bearings of all important points on the shores of the sea, from both stations, the materials are secured for a correct map of it, in its general outline.
This work being accomplished, and the day being now fully spent, the party bade the shores of the sea farewell; and, weary with the fatigues and excitement of the day, they began, with slow and toilsome steps, to reascend the path toward their encampment by the fountain. They at length arrived at their tent, and spent the evening there to a late hour, in writing out their records of the observations which they had made, and of the adventures which they had met with during the day. From time to time, as the hours passed on, they looked out from their tent to survey the broad expanse of water now far below them. The day had been sultry and hot, but the evening was cool. The air was calm and still, and the moon rising behind the eastern mountains shone in upon their encampment, and cheered the solitude of the night, illuminating, at the same time, with her beams, the quiet and lonely surface of the sea.
THE SALT MOUNTAIN OF USDUM
At a subsequent period of his tour in the Holy Land, Robinson approached the Dead Sea again, near the southern extremity of it, and there examined and described a certain very remarkable geological formation, which is justly considered one of the greatest wonders of this most wonderful valley. It is called the Salt Mountain of Usdum. It is a lofty ridge that extends for a great distance along the shore of the sea, and consists of a solid mass of rock-salt. The situation of this mountain, as will be seen from the map, is on the southwestern shore of the sea. There is a narrow tract of low and level land between the mountain and the water. The road passes along this plain, close under the cliffs, giving the traveler a very convenient opportunity of examining the formation of the mountain as he journeys with his caravan slowly along.
The existence of such a mountain of salt was asserted by certain travelers many centuries ago, but the accounts which they gave of it were not generally believed, the spot being visited too seldom, and the accounts which were brought from it being too vague and imperfect to confirm sufficiently so extraordinary a story. Robinson, however, and other travelers who have, since his day, fully explored the locality, have found that the ancient tales were true. The ridge is very uneven and rugged, its summit and its sides having been furrowed by the rains which sometimes, though at very distant intervals, fall in this arid region. The height of the ridge is from one hundred to one hundred and fifty feet. The surface of the hill is generally covered, like that of other rocky ridges, with earth and marl, and sometimes with calcareous strata of various kinds, so that its true character is in some measure concealed from ordinary and casual observers. The mass of salt, however, which underlies these superficial coverings, breaks out in various places along the line of the hills, and sometimes forms perpendicular precipices of pure crystalized fossil salt, forty or fifty feet high, and several hundred feet long. The traveler who beholds these crystaline cliffs is always greatly astonished at the spectacle, and can scarcely believe that the mountain is really what it seems, until he has gone repeatedly to the precipice and broken off a fragment from the face of it, to satisfy himself of the true character of the rock, by tasting the specimen.
The mountain extends for two or three miles along the shore, drawing nearer and nearer to it toward the south, until at last it approaches so closely to the margin of the sea, that the waters, when high, wash the foot of the precipice. Along the road which lies between the cliffs and the shore, and upon the beach, masses of salt are found, which, having been broken off from the heights above, have fallen down to the level land below, where they lie like common rocks upon the ground. Here and there ravines are found, forming little dells, down which small streams are constantly trickling; and, in some seasons of the year rains fall, and, dissolving small portions of the rock, flow with the solution into the sea below. Of course, what salt finds its way into the sea remains there forever, except so far as it is carried away by man – for the process of evaporation takes up the aqueous particles alone, from saline solutions. A very small annual addition is therefore sufficient to keep up the saltness of such a sea. It is supposed that this mountain is the source which furnishes the supply in this case. If so, the Dead Sea, geologically speaking, is simply an accumulation of the waters of the Jordan, formed in a deep depression of its valley, and made salt by impregnation from a range of soluble rocks, the base of which they lave.
THE CAVERN
At one point in the eastern face of the Usdum mountain, that is the face which is turned toward the sea, there is a cavern. This cavern seems to have been formed by a spring. A spring of water issuing from among soluble strata will, of course, always produce a cavern, as its waters must necessarily dissolve and wear away the substance of the rock, and so, in the process of ages, form an open recess leading into the heart of the mountain. The few European travelers who have ever passed the road that leads along the base of this mountain, have generally stopped to examine and explore this cavern. It is irregular in its form, but very considerable in extent. The mouth of it is ten or twelve feet high, and about the same in breadth. Robinson and his party went into it with lights. They followed it for three or four hundred feet into the heart of the mountain, until at length they came to a place where it branched off into two small fissures, which could not be traced any farther.
