28 



NATURE 



[May 13, 1897 



tains"), I'M the oases Niya and Cherchen, to lake Lob- 

 nor, Roborovsky and Kozloff, with two or three men, 

 pushed into the mountains, and beyond, into the wilder- 

 nesses of the northern part of the Tibet plateau. These 

 excursions, which were made under great difficulties, 

 and in one of which Roborovsky's party was very 

 nearly lost, are described in the present part of the 

 " Works " of the expedition, and illustrated by six maps 

 on the scale of 13 miles to an inch. The most important 

 of these reconnoitring expeditions was the second, made 

 by Roborovsky, when he crossed the Astyn-tagh, and, 

 following a valley at its south-eastern foot, between the 

 Astyn-tagh and the steep snow-covered Uzu-tagh, reached 

 the Keria river, as it issues from the Tibet plateau and 

 turns north-westwards, fringing the mighty glacier-covered 

 Kuen-lun. No inhabitant of Kashgaria ever went that 

 way, and nobody ever came to Kashgaria from that 

 quarter ; only a few gold-diggers visit the above-men- 

 tioned valley, without ever daring to penetrate further 

 south into the dreary wilderness of the high plateau. 

 Roborovosky did so, notwithstanding the terrible snow- 

 storms, one of which, on May 22, covered the ground 

 with three inches of snow. After having reached the 

 Keria river, which flows at an altitude of 14,300 feet, 

 and must be a mighty stream in summer, Roborovsky 

 returned ; but he came once more to the same spot, 

 a couple of weeks later, moved by the desire of crossing 

 the Uzu-tagh and of casting a glimpse on the dreary 

 desert in the south of it. The altitude of the desert was 

 16,600 feet, and on June 12-14 almost no signs of life 

 were found on it. Its surface is covered with low rows 

 of stony hillocks, consisting of sharp-edged broken strata 

 of quartzite, running west and east. A few bushes of a 

 willow were found after a 22 miles' march, but no 

 lichens were seen ; and the only animals noticed were a 

 few broken-down (?rtfA!^<7-antelopes, which slowly walked 

 within a few yards from the party — too weary to pay 

 attention to it. Only snow seems to fall all the year 

 round in this desert, and rain must be quite unknown- 

 In June, snow fell every day, and evaporated imme- 

 diately. On June 15 the altitude was 17,080 feet, and the 

 temperature - 12° Celsius in the morning. The horses 

 were severely suffering from the sharp stones, and broke 

 down ; so that the party was compelled to return, after 

 having covered only 40 miles southwards. The desert 

 stretched further south, as far as the foot of the snow- 

 covered Kuen-lun. The return journey was extremely 

 difficult, one horse only being able to stand it ; and it was 

 in a desperate condition that Roborovsky's party reached 

 a spot where they had left some of their provisions. 



The sand-storms in that part of Kashgaria, at the foot 

 of the mountains, are simply terrible. The loess-terrace, 

 which fringes the highlands, is easily destroyed by the 

 wind, and the dust is carried in the air, becoming 

 occasionally so dense that complete darkness prevails 

 — nothing being seen at a distance of some ten yards. 

 If it rains during such a dust-storm, the drops df rain 

 evaporate as they fall, and the dust they carry with them 

 falls in the shape of small lumps. Whole forests of 

 poplars are buried in the loess-dust hillocks, forty feet 

 high being blown round the trees, which soon die and 

 slowly decay, after the wind has carried the hillock away, 

 to spread the dust further on. 

 NO. 1437. VOL. 56] 



Another exciysion into the highlands, during which 

 nearly 500 miles were covered and mapped, was made to 

 lakes Achik-kul, Chom-kum-kul, and " Unfreezing " — a 

 salt lake at an altitude of 13,300 feet, which has various 

 species of Gamniariis among its fauna — and to Prjeval- 

 sky's Ridge, which is a mighty chain of mountains, 

 buried in snow, running west and east under a number 

 of local names, and very rich in animal life in its 

 northern spurs. 



A fourth excursion was made along the Cherchen-daria, 

 which flows in a flat-bottoraed valley, and has on both its 

 sides two strips of sands, arranged by the wind in the 

 shape of harkhans (rows of hillocks), attaining the extra- 

 ordinary height of 360 feet. Great numbers of wild 

 camels, stags, antelopes, wild cats, boars, and masses 

 of small rodents and spiders, belonging to a variety of 

 species, inhabit these sands, while the banks of the river 

 are covered with poplars, tamarisks, and rushes. Traces 

 of recent desiccation are found everywhere, and immense 

 spaces are occupied with marshes, now covered with 

 rushes, and strewn up with masses of fresh-water molluscs 

 — the former inhabitants of a great lake. The population 

 of the Lob-nor depression consists of half-breeds between 

 Aryans and Turco-Mongols, who live in huts made of 

 rushes, keeping some cattle, and carrying on fishing to a 

 great extent. 



The accounts of Roborovsky's and Kozloff's excursions 

 to lake Bagrach-kul, near Karashar, and Kozloffs, up the 

 Konche-daria, are also full of interest, and, like the pre- 

 ceding, give a good idea of the physical characters, flora 

 and fauna, of the visited regions. General Pyevtsoff's 

 discussion of Roborovsky's altitudes and astronomical 

 observations completes this very interesting volume. 



P. K. 



OUR BOOK SHELF. 

 Algebra for Beginners. By T. Todhunter. New edition, 



revised and enlarged by S. L. Loney. Pp. xxxvi -t- 428. 



(London : Macmillan and Co., Ltd., 1897.) 

 This excellent elementary treatise is too well known to 

 require detailed description in these columns, so we need 

 only refer to the changes which have been made by the 

 reviser of the new and enlarged edition. Prof. Loney has 

 given additional chapters on negative quantities, the 

 theory of quadratic equations, logarithms, and miscel- 

 laneous theorems, each of which has been inserted in those 

 parts of the book which seemed most appropriate. The 

 chapter on factors has been rewritten, and chapters 

 towards the end have been considerably expanded. By 

 renumbering the paragraphs, and maintaining the old 

 numbers in smaller type, the reviser has facilitated the 

 use of employing both editions together ; the newly-added 

 paragraphs contain only one — namely, the new — system 

 of numbers. As examples form a very important part of 

 such an elementary book as this. Prof. Loney has 

 thought fit to more than double the original number, the 

 answers being, as usual, included in the list at the end. 

 Teachers will thus find in this edition a most complete 

 and efficient course, and one especially adapted for boys 

 commencing the subject. 



Picture Lessons in Natural History. A series of 

 diagrams on roller. (London : G. W. Bacon and Co., 

 1897.) 

 The four sheets before us, which, we presume, form only 

 a portion of the series, include the Protozoa and " Inver- 

 tebrates." From all points of view they seem admirably 



