August 5, 1887.] 



SCIENCE. 



63 



forms one enormous system stretching from the Pamir Plateau to 

 western China. Its most northern range is formed by the Taguz 

 Daban, the Altin Tagh, and Nan Shan. It was on his second jour- 

 ney, in 1876, that Prejevalsky explored this region. He advanced 

 from Kulja on the Hi. which he describes as the most lovely district 

 of Central Asia, crossed the Tian Shan, and descended to the oasis 

 of Karashar, on the Bagrash Kul. Here he turned south, and, 

 after having reached the Tarim, followed it until he reached the 

 famous Lob Nor (Lake Lob). He stated the remarkable fact that 

 the western part of this lake, which has no outlet, contains fresh 

 water, — a fact which he verified on his fourth expedition. He 

 concluded that Lob Nor is a reedy lake of no great depth, sur- 

 rounded by flat shores, the haunt of prodigious numbers of water- 

 fowl, and inhabited by a few hundred human beings, whose habits, 

 tenements, and mode of life, resemble those of the primitive lake- 

 dwellers. The eastern part of the lake must be salt, as it is an 

 inland lake, and all the matter contained and dissolved in the waters 

 of the Tarim is carried into it. 



His most important discovery here was that a high chain of 

 mountains, the Altin Tagh, rises almost precipitously from the 

 southern shore of the lake to the limit of perpetual snow. On his 

 fourth expedition he completed these discoveries by that of the 

 high chains of mountains forming the western and southern bound- 

 aries of Tsaidam. 



He had explored this saline marshy district on his first journey, 

 1871 -73, and thence had visited northern Tibet, with the intention 

 of visiting Lhasa ; but when about five hundred miles from this 

 place he was compelled to turn back. 



The same region was the goal of his third expedition. Well 

 supplied with funds, he started from Zaisan, in the government of 

 Semipalatinsk. His party numbered thirteen all told, ten being Cos- 

 sacks. They travelled along the south shore of Lake Urungu, and 

 ascended the Ulyungur. The natives of this river and its chief 

 tributary, the Bolgun, are Targute-Kalmuks, whose kinsmen, in- 

 habiting north-western Dzungaria, are the descendants of those 

 Kalmuks, who, driven out of their camping-grounds by the Dzun- 

 gars, migrated to the banks of the Volga and LTral, and in 1770 

 suddenly departed, to the number of four hundred and sixty thou- 

 sand families, and at last settled on the Hi. 



Prejevalsky crossed from the Ulyungur to the eastern continua- 

 tion of the Tian Shan, and, passing the plain of Barkul, he at last 

 arrived at the oasis of Hami, which he describes as remarkably 

 productive. Corn, vegetables, grapes, and melons are grown there, 

 the last being of such exceptionally fine flavor as to be considered 

 worthy of being sent to the Court of Peking. It is a place of the 

 highest importance, as it commands the chief roads from China to 

 eastern Turkestan and Dzungaria. From here, roads lead to the 

 cities situated along the northern foot of the Tian Shan, and across 

 the desert of Gobi to Sha-chau, on the upper Bulunzir. This oasis 

 is situated at the foot of the Nan Shan, which is here a chain of 

 mountains only twenty-seven miles in width ; though farther east, 

 near the Koko Nor, it attains far greater dimensions. Still farther 

 east, in the province of Kansu, the mountains are covered with 

 dense forests ; but near Sha-chau it is a sterile, treeless range. Yet 

 the highest parts possess a savage grandeur, with their summits 

 towering above the main axis, their precipices, snow-covered peaks, 

 and glaciers. 



The expedition now entered the plateau of Tsaidam, — an ex- 

 panse of salt marsh and clay flats dotted with lakes, and elevated 

 about ten thousand feet above the sea. The level and desolate 

 character of this country is shown in Fig. 2, which is reproduced 

 from Le Tour du Monde. 



Another characteristic feature of this region is shown in Fig. i, 

 which has been taken from the same journal. Around the 

 shrubs and bushes masses of sand and dust are accumulated by 

 the wind, and thus in course of time a small hill is formed, on the 

 top of which a new shrub begins to grow. Von Richthofen's re- 

 searches show that the masses deposited by the wind are distrib- 

 uted over a wide area in Central and Western Asia, and that the 

 form of the surface of this region is principally due to the action of 

 the wind. 



Tsaidam forms the first terrace of the plateau of Tibet. On its 

 northern and southern sides it is enclosed by the branches of the 



Kwen Luen, while the spurs of the Nan Shan form its eastern limit. 

 The southern part, which was formerly covered by an extensive 

 salt lake, is extremely level, while the northern section is higher and 

 hilly, and is composed of a barren, sandy ground and saline 

 marshes. The inhabitants of this region are Mongols. Their 

 principal occupation is stock-raising. In summer the herds are 

 driven to the mountains, as the lower parts of the country swarm 

 with insects. On account of the great distance of the agricultural 

 districts of China, and the difficulty of obtaining grain, the inhabit- 

 ants till the soil to a limited extent. As they are frequently at- 

 tacked by the Chara Tanguts and the Golyks of the river Mur-usu, 

 they fortify certain parts of their camps and villages, in which they 

 defend themselves from their enemies, whose predatory excursions 

 are said to be permitted and supported by the Chinese governor. 



Though the inhabitants of Tsaidam received Prejevalsky well, the 

 native princes, acting doubtless by orders from Peking, refused 

 him both guides and provisions ; but at length he succeeded in 

 starting on his way south. After they had passed the Shuga and 

 Baian-kara-ula Mountains, the difficulties of travelling increased 

 greatly. Their guide, who had only once, fifteen years before Preje- 

 valsky 's journey, traversed that country on his way to Lhasa, did not 



know the way, and the caravan had to select the way according to 

 their own judgment. They succeeded in reaching the Napchitai- 

 ulan-muren, where they found traces of caravan camps, which as- 

 sured them that they were on the right road. Though it was only 

 the middle of October, the weather turned cold, with continued 

 snowfalls, and their camels and horses could find nothing to eat. 

 Thus, under great difficulties, they succeeded in crossing the Koko- 

 shili and Dumbure Mountains. Having reached the valley of the 

 Mur-usu, they struck the track taken by the Lhasa pilgrims, and 

 ascended the river. But soon the track was lost again ; and, after 

 having deposited part of the load in a cache, the caravan proceeded 

 southward, and crossed the Tangla Range by a pass which, though 

 16,700 feet in height, is only 2,100 feet above the valley of the Mur- 

 usu, and has a very gradual slope to the north and south. The 

 eastern continuation of this mountain-range is probably the water- 

 shed between the Yang-tse-Kiang and the rivers of Farther India ; 

 but we are far from having a sufficient knowledge of the compli- 

 cated river-systems of this region. It is even still doubtful whether 

 the Nap Chu is the upper course of the Salwen as represented on 

 our map, or of the Irawadi, as some authiorities on the geography of 

 Farther India suppose. Prejevalsky now reached the valley of the 

 San Chu ; but here his further progress was stopped, as the Dalai- 

 Lama did not permit him to enter his territories. So he was com- 

 pelled to return, though only one hundred and fifty miles from Lhasa, 

 the goal of his journey. 



