Himavava Mountains. 319 
ebserved with the theodolite and deduced from comparisons with the. sin, 
(a method not capable of the same precision as that of clongations, it 
was thought more correct to confine ourselves to the original Azimuth from | 
Gelville, determined in so much more satisfactory a manner. The others 
indeed were principally ebserved as checks, and to be an assurance against 
the intrusion. of any errors, not properly. belonging to the subject. . 
Saar 
Barometrical Observations.to determine the Height of the Station near 
Saharanpir, above the level.of the Sea. 
Tuis important point it is hoped is satisfactorily settled fromthe eigh- 
teen corresponding barometrical observations made at Saharanpir and: 
Calcutta, for that express —:purpose, with. correct mountain. barometers, in - 
which the-level of the mercury im the cistern can always be adjusted. . As 
for want of the verification of the zero -of their scales, the observations. 
usually made in Calcutta for meteorological purposes, are’ not sufficiently 
correct, to use as correspondents where differences of height are desired: 
we rather chose, to determine the differences of height of Sakéranpir, and - 
the sea, from the assamed mean height at which the mercury is supposed 
by philosophers to stand: at the sea level, on-an average of the whole 
year, but to render that mode of comparison, perfectly correct, it would” 
be necessary, to. have the observations, taken..during twelve months at. 
Saharanpur ;- therefore, on» the -arrival’ ef a perfect mountain barometer” 
in Calcutta, an: actual cotemporancous comparison. was immediately insti- - 
VOL. XIV. 4 WE 
