274 ANNUAL OF SCIENTIFIC DISCOVERY. 



accumulation of the great delta of the Nile, we have recently been 

 put in the way of learning, what has been the amount of the wear 

 and tear of upland or granatic rocks, and what the additions to the 

 great alluvial plain of Lower Egypt, since man inhabited that most 

 holy region, and erected in it some of his earliest monuments. But 

 how long will it be before we shall be able to calculate backwards by 

 our finite measure of time, to those remote periods, in which some of 

 the greatest physical features of this continent were impressed upon 

 it, when the lofty mountains from which the Nile flows, were 

 elevated, and when the centre of Africa was a great lacustrine jungle, 

 inhabited by the Dicynodon, and other lost races of animals ? 



WESTERN HIMALAYA AND TIBET. 



IN the years 1847-8, an expedition was fitted out by the East India 

 Company, for the exploration of the western Himalaya and Tibet. 

 A journal of these travels and geological researches, has recently 

 been published in England, by Dr. Thomson, one of the party, and 

 a son of the celebrated chemist of that name. From this book, 

 which contains much new and interesting scientific information, we 

 derive the following extract. Many of the places examined and 

 described, have never before been visited by any European traveller. 

 The old, and still popular notion of Tibet, is that of a great mountain 

 table land, or a series of table lands, at the back of the Himalaya, by 

 which mighty chain its southern boundary is made, a barrier broken 

 through by the Indus at one extremity, and the Brahmaputra at the 

 other, while its northern limit is similarly walled in by the Kouenlun 

 chain ; the country thus supposed to exist is entirely imaginary. 

 There is, indeed, no such table land. Nor is there, indeed any such 

 great continuous chain as the Himalaya itself. The line of snowy 

 peaks running parallel to the plains of India are not so many sum- 

 mits of one Alpine chain, but are separated from each other by deep 

 ravines, through which floAv large and rapid rivers. Between the 

 Indus and the plains of north-west India is a rugged and mountainous 

 track 150 miles broad. Kashmir is the only plain of any extent 

 among these mountain ranges. The mountains between the Indus 

 and the. plains may be referred to two great groups, which may be 

 respectively termed the Cis-Sutlej and Trans-Sutlej Himalayas. 

 Tibet is the region among and of these mountains between their outer 

 ramifications and the great chain of Kouenlun beyond the Indus. 

 This chain separates Tibet from Yarkand and Kohoten. Over this 

 stupendous barrier there are said to be only four passes, all crossing 

 regions of eternal snows, and two traversing enormous glaciers. The 

 Karakoram Pass is one of these, and is 18,200 feet above the level of 

 the sea. The visit to this extraordinary locality is thus described by 

 Dr. Thomson : 



" On the 19th of August, I started to visit the Karakoram pass, the 

 limit of my journey to the northward. The country round my halt- 

 ing-place was open, except to the north, where a stream descended 

 through a narrow valley from a range of hills, the highest part of 



