1SGJ.] 
165 
Proceedings of the Asiatic Society. 
been from 20 to 30 miles in length. Their present size, so much 
exceeding those that have been found in more easterly parts of the 
Himalayas, is no doubt due, in some measure, to the increase of 
latitude, as well as to the great height of the peaks, which are 
absolutely higher than any others west of Nipal. 
Captain Montgomerie pointed out that the highest peaks had 
generally been found on the spurs, at some distance from the water- 
shed lines. 
After a description of the rope-bridges used in the country, he 
explained that the heights of the Kashmir series depended upon those 
of the N. W. Himalaya series, and those heights had been tested by 
trigonometrical levelling, carried round Colonel Waugh’s great 
geodetical quadrilateral, viz., from Kurrachee to Sirouj, Sirouj to 
Debra Dhoon, thence to Attock, and back again to the original 
starting point. This circuit of no less than 2,500 miles, closed with 
a discrepancy of only £ of a foot by one set of levels, and of 1J feet 
by another. 
The Kashmir series consequently may be said to have started, with 
as accurate heights as nature would admit. The heights of the series 
itself have been tested in a similar way, the effects of attraction are 
known to be cancelled, in some measure, in the Kashmir series, as 
Captain Montgomerie’s latitude observations shew that there is in 
the mountains a strong Southerly as well as Northerly attraction. 
Every care has been taken to diminish the uncertainties of the 
refraction, which, in the lower hills, was about 1-lGth, and in the 
higher ground, as little as l-25th, of the contained arc. 
Sir Andrew Waugh’s system of trigonometrical levelling was ex- 
plained, the main features being the taking of vertical observations 
at the time of minimum refraction, between 2 to 3 p. m., repetitions 
of observations on different days, and strict adherence to the same 
apparent time for reciprocal observations. This system makes the 
trigonometrical levelling a rival to the spirit levelling, more especially 
in hilly ground. 
For instance, the trigonometrical levelling from Kurrachee made a 
point near Attock 1014 feet 6 inches, and the spirit levelling made 
the same 1012 feet 3 inches, being a difference of little over 2 feet in 
830 miles. The spirit levelling was carried out with the best modern 
instruments of the largest size, and with every possible precaution to 
y 2 
