2 HAYDEN: GEOLOGY OF THE PROVINCES OF TSANG AND 0. 
was at once recognised and it was decided that a geologist should 
join the mission at Kampa dzong. 
The results of the traverse subsequently made through a consider- 
able part of Central Tibet are embodied in the following pages, 
which^ however, do not claim to give more than the merest outline 
of the geology of the area passed through, for although, during the 
early months of peaceful expectancy at Kampa dzong, it was found 
possible to make a fairly extensive examination of the surrounding 
country, yet after the transfer of the scene of operations to the Chumbi 
Valley, the exigencies of a military expedition confined observations 
almost entirely to the bare line of march. 
I must once more record my great indebtedness to Sir F. E. 
Younghusband, K.C.I.E., vi^ho did so much to forward every branch 
of scientific enquiry and earned, both by his never-failing sympathy, 
as well as by material aid always so generously given, the deep 
gratitude of all who were privileged to work under him. My 
thanks are also due to many members of the mission and escort for 
frequent assistance in the collection both of geological specimens and 
of information : I am especially indebted to Messrs. J. C. White, C.I.E., 
E. H. Walsh, I.C.S., E. C. Wilton, C.xM.G., Major C. H. D. Ryder, 
R.E., D.S.O., Captains W. F. O'Connor, C.I.E., H. M. Cowie, R.E., 
and R. Lloyd, I. M.S., and Lieutenant F. M. Bailey. 
CHAPTER h 
PHYSICAL FEATURES, 
I. Mountain Systems. 
On the map compiled by Trelawney Saunders and published 
in Sir Clements Markham's edition of the narratives of Bogle and 
Manning,^ the Himalaya mountains are shown, so far as their eastern 
division is concerned, as consisting of two distinct and continuous 
ranges lying to the south of the Tsangpo and running parallel to 
1 2nd e:iition (1879). 
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