m DESERTS. 



ThU deaert, occupied by Arab* living upon plunder, U traversed by 

 the oaravaiu which carry on the commerce between Haleb and Bagdad. 

 IU southern portion, or Irak-Arabia, present*, by ream of the 

 proximity of the two riven, an aspect quite different from that of 

 Aljesireh. That portion of the plain which form* the ancient Baby- 

 lonia is ooTered with alluvium, and, like the delta of Egypt, U periodi- 

 cally inundated. It U an immenee meadow, requiring only the hand 

 of induetry to be covered a* heretofore with abundant harvests, and to 

 become one* more the garden of Asia, 



Detrrit of Ptrtio. - Scarcely have we left behind us theee dismal 

 region*, (till directing our course eastward, and near the 84th parallel 

 of N. lat, when we meet with the mountain* of Kurdistan, covered 

 with forest*, and interacted by fruitful valley*. 



Having acaled thi* wall, which form* the eaitern boundary of the 

 basin of the TigrU and Kuphratee, we find ounelvn on the high table- 

 land of Peru*, where we again meet with extenaive deaert*, aome of 

 them sandy, *uch a* we have already aeen, but more generally of an 

 argillaceous soil ; and thus it is that the Persian deserts seem to form 

 the transition between those of Africa and Arabia and the Tartarian 



In Persia there are five principal deserts, which occupy about three- 

 tenths of the surface of the country. Of these the first is the great 

 salt desert, which separates Irak-Ajemi from Khorassan, and is about 

 130 leagues long and 70 wide. On the south it joins the desert of 

 Carmania; on the east it unite* to the province of Khorasaan. Its 

 soil is a stiff clay, whose surface is covered with a saline efflorescence 

 in some places an inch thick ; and its vegetation, as in all the high 

 plains of the country, consist* of saline plants, such as the Static? 

 Tartarica, intermingled with a few patches of pasture. The three 

 other deserta are those of Kiab, of Heckran, and of Karakoum. The 

 desert of Meckran U in Beloochistan. It is bounded on the south by 

 the sea of Oman, and is separated from the desert of Sinde in Hiii- 

 dostan by the Brahouic mountains and the Indus. It does not belong 

 to the table-land of Persia, but to the basin of the sea, of which it 

 forms the northern boundary, or coast line followed by a part of the 

 army of Alexander the Great on it* return from India. It* produc- 

 tions differ from those of the Great Desert, and consist of the Indian 

 palm, and the aromatic shrubs of Arabia Felix. The desert of Kara- 

 koum is to the north of Khoraasan ; it is sandy. 



Daert* of Grand Tartary. Descending the Paropamisian mountain!) 

 which bound Khorassan on the north, and form in that direction the 

 escarpment of the great high-land of Persia, of which the sandy 

 province of Kohistan seems to form the ridge, we enter upon the 

 deserts of Independent Tartary. This country is bounded on the 

 south by the Paropamisus already named, and by the lofty chain of 

 the Hindoo Koosh, of which it seems to be the continuation; on the 

 east by the high mountains which separate it from China; on the 

 north by aome ridges, which on the one hand descend from the great 

 Altaic chain, and on the other from the extremity of the Uralian 

 mountains ; and on the west by the Caspian. It may be regarded as 

 the north-western declivity of the great central platenu of Asia, It 

 occupies a surface of about 60,000 square leagues, of which the 

 greater half is a desert ; for, with the exception of the immediate 

 foot of the mountains and the water-courses, the whole country is 

 condemned to drought and sterility. The saline and sandy plains 

 extend even round the northern part of the Caspian as far as the 

 Don, and, to the east of the Ural, join the steppe of Isim, claimed by 

 Russia. 



The country of Khowarezme or Earissnm on the south of Lake 

 Aral is now reduced, by causes among which the invasion of the sands 

 is perhaps the most powerful, to the little district of Khiva, which 

 rise* like an oasis in the desert, and which a man may ride round in 

 three days. 



The greater Buoharia, or Bokhara, is also surrounded by sands to 

 the north and west. The whole of Independent Tartary at the present 

 time perhaps hardly contains a population of five millions, a proof of 

 the extreme sterility of the soil. 



On the south-east of the province of Kohistan, of which we have 

 spoken, is situated Segestan, and the country of the Afghans. 



Dettrt of Afghanistan. Afghanistan is an extensive country, con- 

 taining the city of Candahar. [AFGHANISTAN, in OEOO. Drv. It is a 

 vast andy basin, except in the immediate vicinity of the mountains 

 by which it is bounded on the east and north, and along the banks of 

 the rivers Lhonh and Helmend or Hindamend, which latter traverses 

 it from east to we*t, and terminates in the Lake Zorah. The land 

 ne* on the north-east towards the lofty mountains which sustain 

 the great central plateau of Asia, and from which descend the Indus 

 towards the south-wort, and the Ganges to the south-east 



The vast extent of arid dewrU which we have jut described, 

 carcely interrupted by the Indus itaelf, reaches to the very banks of 

 the Hesydnis, the most eastern of the rivers of the Punjab 



From Cape Bujador on the Atlantic to beyond the Indus, the sandy 

 region extend* in a curved line of 1400 geographical miles, and setting 

 aiide the fertile oases, is estimated by Humboldt as covering a surface 

 of 300,000 square leagues; and yet, however extensive this tract which 

 aeems condemned to eternal sterility, we have still to consider the 

 at central table-land of Asia, not leas arid than what we have just 



DESERTS. 481 



Dacrti of Ike Grrat Central Plateau of Aria. The first country we 

 meet with a* we go eastward is Little Bucharia, bounded on the north 

 by the mountain chain of Alak, which separate* it from Songaria, and 

 on the south by the Moos Tagh and Great Tibet. On the east it joins 

 Mongolia. 



Little Bucharia is tolerably fertile near the mountains, whence 

 deeoeod innumerable streams, which, uniting in the river Yarkand, 

 flow with it into the Lake Lop, having no issue. The whole of the 

 centre and eastern portion of the country is sandy and salt 

 desert. 



Leaving on the north Songaria, which also contain* immense arid 

 spots, and whence the river Irtish take* it* rue, still continuing our 

 route towards the east, we find the sterile plain extending towards 

 Mongolia, where it open* out to form the vast desert of Shamo, which 

 extends to the Great Wall of China through a length of 600 leagues, 

 rarely interspersed with a few fertile spots. 



From the outer slopes of those mountains which inclose and sustain 

 the central plateau, the highest in the world, descend those mighty 

 rivers which, on the one hand, fertilise the great empire of China, and 

 pour the tribute of their waters into the Pacific, and on the other, 

 traverse the widely-extended tttpptt of Siberia to disembogue into the 

 Frozen Ocean. 



As for the area of the sandy deserts of the Tartarian table-land, it 

 may on a very moderate computation be estimated at 100,000 square 

 leagues, which, together with the former 300,000 for the African, 

 Arabian, and Persian deserts, and about 100,000 more for the widely- 

 spread sandy and barren tract* in the south of Africa, and sandy patches 

 of Europe, gives a grand total of half a million square leagues of desert 

 in the Old World alone; that is,a surface equal to the whole of Europe, 

 or forty-four times the extent of Great Britain, and this without inclu- 

 ding the boundless tleppet of Siberia, or the marshy plains of Northern 

 Asia bordering on the icy sea. 



A peculiarity of character in the enormous heat and aridity of the 

 Australian deserts, and which also appears to be extended, though in 

 on inferior degree, to those of South Africa, has a cause purely astro- 

 nomical the greater proximity of the earth to the sun at the period 

 of the summer solstice in the southern hemisphere, and winter solstice 

 in the northern; and was pointed out a few years since by Sir 

 J. F. W. Herschel, in his Elements of Astronomy ' (869), tc. This 

 peculiarity is so remarkable, and would appear 'to be in its turn the 

 cause of so many phenomena, characterising the physical geography 

 and all the three kingdoms of nature in Australia, that it is requisite 

 to enter more particularly into the subject than might at first sight 



:I]>I.IMV ll'-i-i --.TV. 



For half the year the earth is one-thirtieth part nearer the suu than 

 in the other half-year, and the difference of the sun's direct heating 

 power amounts, iu consequence, to one-fifteenth of the whole ; but 

 during that half-year, precisely, the earth moves quicker in iU orbit, 

 and therefore does not receive any more heat than in the other half- 

 year when it moves slower, at a greater distance from the sun. No 

 inequality therefore exists between the mean temperature of the two 

 hemispheres, but on equal and impartial distribution of heat is accorded 

 to both. 



The perihelion of the earth's orbit, however, the point where the 

 earth i nearest to the sun by 8,000,000 of miles, is nearly at the place 

 of the southern summer solstice, so that the effect of the greater heat- 

 ing power of the sun, owing to the smaller distance of the earth at this 

 particular time, the midsummer of the southern hemisphere, is really 

 to augment the local temperature of places in that hemisphere. This 

 causes the direct impression of the sun's heat in the height uf em 

 to use the words of the original elucidator of the subject : " The 

 glow and ardour of his rays under a perfectly clear sky, at noon, in 

 equal latitudes and under equal circumstances of exposure," to be 

 " very materially greater in the southern hemisphere than in the 

 northern." One fifteenth is too considerable a fraction of the whole 

 intensity of sunshine," continues Sir J. Herschel, " not to aggra , 

 a serious degree the sufferings nf those who are exposed to it in : 

 deserts, without shelter. The account* of these sufferings in the 

 interior of Australia, for instance, are of the most frightful kind, and 

 would seem far to exceed what have ever been undergone by travellers 

 in the northern deserts of Africa," 



Facts illustrative of this peculiarity of the Australian desert*, great 

 part of which, in consequence, and on account of their mineralogical 

 constitution, ore in the state of compact highly-baked earth, will be 

 found in the relations of their explorers; especially in Caj.t. Sturt's 

 Narrative of his expedition into Central Australia. He remarks, that 

 the ground was almost a molten surface ; and the progress of one of the 

 most recent expeditions is stated to have been terminated by the 

 ground having assumed the condition of the top of a glowing brick-kiln ; 

 properly, of a clamp of burning bricks. Capt. Stokes, R.N., has recorded 

 in his ' Discoveries in Australia,' circumstances which evince that the 



It mail be remembered, that, as If to counteract ny possible tendency of 

 thli to disturb the general equlibrium or balanced condition of the earth's 

 surface, on which the well-being of the human race and of organic nature in 

 general depend*, the land being greater in extent in the northern hemiiphere, 

 which baa Its lummer toliuoc in June, the temperature of the whole (a* Pro- 

 fcuor DOTC baa shown) ti greater in that month than U U In .December, when 

 the earth is actually nearest the sun. 



