[No. 2. 
106 Proceedings of the Asiatic Society. 
ensure accuracy. The trigonometrical levelling, had moreover, had 
its own tests, and had stood them well, after traversing unprecedent- 
edly great distances ; thus, starting from the sea at Calcutta, the 
trigonometrical levelling closed at Bombay, with a discrepancy of 
only 6f feet in a circuit of 2127 miles, similarly from Calcutta to 
Kurrachee, 2082 miles, there was a discrepancy of 16| feet. 
The result of the comparison of these two systems over such a 
very long line was highly gratifying, and shewed the great value of 
the trigonometrical levelling, which, in the infancy of geodesy, was 
neglected, or at any rate, not made full use of, in Europe and other 
places. 
The Kashmir series observations afforded ample proof of the 
reliability of the heights of inaccessible peaks, for, many as high as 
20,000 feet, which were at first computed as inaccessible points, have 
subsequently been visited as principal stations, and their new values 
as accessible stations, have agreed very closely with those determined 
before the station was visited. No greater difference, in fact, was 
found than could be easily accounted for, by the difference in depth of 
the snow at different periods, &o. 
A short account was then given of the Kashmir series triangulation, 
which is connected with the triangulation of India, and has been 
carried over three snowy ranges, and across the great Himalayan 
range in two places by stations built on its peaks. 
The observations of the principal series were invariably taken to 
luminous signals, viz., heliotropes and lamps. 
Great difficulty was experienced in building the masonry pillars 
and platforms on the snowy peaks. The highest part of the snow 
was not always over the highest part of the rock. Several shafts had 
to be sunk in the snow before the rock could be found ; when 
found, sufficient snow had to be cleared to supply building material 
for the platform. The snow had to be melted to slake the lime. A 
description of an encampment on the snow was given, referring to the 
difficulties necessarily encountered by the Surveyors during a residence 
of at least three or four days on each peak. 
The mountainous nature of the country enabled orders to he trans- 
mitted at great distances by means of heliotrope signals. 
The reverberatory lamps saved great delay, for if the clouds inter- 
fered with the work during- the day, they generally fell to a lower 
