776 
AECHDEACON PEATT OX THE DEFLECTIOX 
Major Steachey, after his brother, calls the northern boundary’ of the table-land the 
Turkish Watershed, and the southern the Himmalayan Watershed (p. 33). 
“ The average elevation of the crest of the Indian watershed most probably exceeds 
18,000 feet. In a comparatively few points only its continuity is broken, and it allows 
the passage of rivers that rise on its northern flank ; but at aU other pomts its summit 
must be crossed in entering Tibet from the south. The passes over it are frequently 
more than 18,000 feet above the sea ; and, except where it is broken through, I know 
of no point to the east of Kashmir where it can be suiunounted under 16,400 feet ” 
(p. 51). 
“ The summit of the table-land, though deeply corrugated with vaUeys and moun- 
tains in detail, is in its general relief laid out horizontally, at a height little inferior to 
that of its southern scarp ” (p. 52). 
The plain along the upper course of the Sutlej “ lies immediately to the north of the 
British provinces of Kumaon and Gurhwal, and is about 120 miles in length, its breadth 
varying from 16 to 60 miles. Its surface, to the eye a perfect flat, varies in elevation 
from 16,000 feet along its outer edges on the south-west and north-east, to about 15,000 
feet in its more central parts, where it is cut through by the river Sutlej which flows at 
the bottom of a stupendous ravine, furrowed out of the alluvial matter of which the 
plain is composed to a depth of 2000 or 3000 feet, and at its west end even more” (p. 53). 
This will account for the statement on the Survey Map (as noticed at p. 75 of my Paper 
of 1855), at the point where the Sutlej leaves the table-land, that the height of hs bed 
is only 10,792 feet. This I have taken in my former calculation as the greatest height of 
any of the compartments into which I divide the surface ; this, therefore, the researches 
of Major Steachey show to be much under the mark. 
On a careful consideration of all the data, Captain H. Steachey estimates the mean 
elevation of the table-land between the Himmalayan and Turkish watersheds, and to the 
west of the ridge between the sources of the Indus and Brahmaputra, to be 15,000 feet 
(P- 5®)- 
3. A comparison of Major Steachey’s map, copied in part in the diagram above, with 
the diagram I have given in former Papers of the “Enclosed Space*,” will show that 
much attracting matter which, from Humboldt’s account, I supposed to exist, in Major 
Steachey’s description does not appear, at any rate not in so important a degree. Lest, 
therefore, it should be thought that, my data being in some respects wrong, my results 
are altogether vitiated, I have examined the effect of these new measm-es, and I find 
that the increased height given to the plateau compensates for the removal ot imy 
attracting mass higher north which I had supposed to exist. 
4. I do not intend to enter anew into a lengthened calculation of the deflection of 
the plumb-line, with a view, as before, to obtain an exact result, because my object will 
be equally answered by taking a simpler course. My object in these various communi- 
cations has been, first, to give an easy method of determining the amount of attraction 
* Pliilosopliical Transactions, 1855, p. 76. 
