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SCIENCE. 



[Vol. XVIII. No. 462 



the extent of which was fairly well distinguishable from this 

 point of vantage, in spite of the glare which surrounded it. 



For miles and miles away at our feet stretched what looked 

 in the distance a vast frozen lake, but which was in fact a 

 deposit of salt that entirely covered the low plains towards 

 the south, and extended as far as the eye could reach towards 

 the east and west, glittering in the suu like a sheet of glass. 

 Towards the extreme west we imagined that this solid sheet 

 was replaced by water, for we fancied we could see the rip- 

 ples on its surface aad the foam along the edge as the wind, 

 which was high, drove it against the shore; but this may 

 only have been owing to the heated air upon the surface, 

 and the broken pieces of salt which were strewn along the 

 margin. We sat for hours looking at this strange spectacle 

 and examining it through our field glasses, while our guides, 

 who were some of the wild Ilyats, or wandering tribes which 

 baunt this neighborhood, entertained us with all manner of 

 strange stories regarding the peculiarities of its composition 

 and the dangers to be encountered in traversing this vast 

 deposit of salt. 



According to their accounts, it was of the consistency of 

 ice, and, like the latter, formed a coat of varying degrees of 

 thickness upon the top of the water or swampy ground which 

 lay underneath it. In some places they declared that this 

 layer of salt attained a thickness of several feet, and that 

 with such a degree of density that laden camels and mules 

 could cross over it with perfect safety; while in other places 

 where -this was not the case, the crust of coagulated salt 

 would break under their weight did they attempt it, and they 

 would be engulfed in the waters or morass below beyond all 

 iope of extrication. There appeared to be but one path, 

 across which only those who were in the habit of traversing 

 it, such as the owners of camels and mules, were well ac- 

 quainted with, and which no one else in consequence at- 

 tempted without a competent guide, for there was but little 

 to mark its course, and if once lost sight of, tlie unfortunate 

 traveller might wander for hours or days without finding it 

 again, and probably end by dying of thirst if he succeeded 

 in avoiding the more dangerous parts incapable of bearing 

 his weight, where he would inevitably be swallowed up. 

 Tliey told us that the passage across this plain was quite im- 

 possible by day, at any rate if the sunshine were very bright, 

 on account of the dazzling eifect which its reflection upon 

 the white surface of the salt produced, which was such as to 

 quite prevent persons attempting it from seeing where they 

 were going; and they recounted numerous instances of cases 

 which had occurred of travellers who had disappeared from 

 losing their way, and never been heard of again. Of course 

 it seemed to us impossible to imagine how all this could be 

 the case, for in a saturated solution of salt and water the salt 

 would naturally be deposited upon the bottum, and not caked 

 upon the surface; the guides, however, were so positive about 

 the truth of what they said, and -the appearance of the plain 

 before our eyes seemed so peculiar, that our curiosity was 

 thoroughly aroused, and we determined in consequence to 

 completely change our intended route for the purpose of 

 crossing the salt, especially as the moon being just at its 

 full, every facility was offered for doing so. Our muleteers 

 we found to make no objection, as they said that they were 

 in the habit of crossing by this route, and that the surface 

 of the salt was so hard and smooth, that it presented capital 

 footing for the baggage animals. The following evening, 

 accordingly, we found ourselves with our whole convoy of 

 eight camels, sixteen mules, and three horses, approaching 

 the margin of this salt plain, which was distant about fifteen 



miles from the foot of the mountain. As we neared this 

 margin, the ground, which had been hitherto hard and dry, 

 became damp and sloppy, so that we had to confine ourselves 

 to moving along a distinct track, which had probably been 

 used for centuries. To judge from the appearance of the 

 ground here, a regular swamp must extend from the salt for 

 some distance along its margin at certain seasons of the year, 

 for on all sides were to be seen marks of animals who had 

 strayed off the track, and got stuck in the clayey mud, from 

 which it would seem in many cases, from the skeletons 

 lying about, that they had been unable to extricate them- 

 selves. 



After following this track, as it wound through this swampy 

 ground for about a mile or so, we entered upon the sheet of 

 salt itself, which, where the incrustation was thin, as was 

 the case for some distance from its edge, was soft and sloppy, 

 and mixed wHh earth resembling very much in its appear- 

 ance the edge of the ice upon a frozen pool when a thaw has 

 set in. As we proceeded, it gained more and more in con- 

 sistency, till, at a distance of three or four miles from the 

 edge, it looked like nothing more than a surface of very solid 

 ice, such as might have been seen on any pond in England 

 during the course of last winter. For this indeed, so far as 

 its appearance went, it might easily have been mistaken, had 

 it not been that, though the whole area over which it ex- 

 tended was perfectly level, the surface itself was not quite 

 even, but resembled more that of ice which had partially 

 thawed and then frozen again after a slight fall of snow; 

 and, further, that instead of being continuous, it was broken 

 up into countless polygonal blocks, whose dimensions varied 

 from about six inches across to two or three feet or more. 

 Of the solidity of this incrustation there could be no doubt, 

 for there we were, camels, horses, and mules, travelling over 

 it without a vibration of any kind being perceptible, or any 

 sign of our weight making an impression on it. After march- 

 ing for about eight or ten miles upon this strange surface, 

 we halted to examine, as far as we could by the moonlight, 

 its composition. We tried, by means of a hammer and an 

 iron tent-peg, to break off a block of salt to take away with 

 us as a specimen, but found it far too hard for us to make 

 an impression upon, and though we succeeded in bending 

 our tent-pegs almost double, we did not accomplish our wish ; 

 we managed, however, to chip off a lot of fragments, which 

 we found here to be of the purest white; these were quite 

 hard when we got them, but after keeping them a day or two 

 they took up so much moisture from the air, that they got 

 soft and friable and changed their color to a slatey hue. 



We were assured by the muleteers and others that at this 

 distance from the edge the salt deposit was as thick as eight 

 or ten feet, and it seemed possible from our failure in the 

 attempt to bore into it that this might not be any great ex- 

 aggeration on their part; they stated also, as I have mert- 

 tioned, that uuder this crust lay, if not standing water, at 

 any rate a quagmire, and that if we had succeeded in our 

 intention of breaking through the salt, the water from be 

 neath would have burst through the opening thus made and 

 flooded all the surrounding space; they further told us that 

 in the winter, when the snow fell and melted on this surface, 

 there was always water standing upon it, and that later on, 

 as the snows on the surrounding higher ground thawed at 

 the approach of spring, this increased to a depth of two or 

 three feet; but that the mules could always cross so long as 

 it did not get too deep for them to find fooling, for that the 

 layer of salt itself never lost any of its solidity, in spite of 

 the water lying on it. 



