trigonometrical measurements at Spitsbergen, 305 
The results of the barometrical measurements, collected in 
one view, are as follows : 
July 17. Height of the Cone. 1644.58 feet. 
It may be seen that the result obtained on the 18th of July 
deviates more considerably than any of the others from the 
general mean ; which may be in some measure, if not en- 
tirely, accounted for by a circumstance which was noticed by 
Mr. Foster at the time of registering the observations, 
namely, that the freshness of the wind on the hill obliged him 
to steady the barometer either with the hand or with a guy ; 
the very slight deviation which may have been occasioned 
thereby from the perpendicular suspension of the instrument, 
would cause the ascent of the mercury in the tube, and in 
consequence render the deduction of the height of the cone 
erroneous in defect ; and such it would appear to have been. 
It will be further seen that the particular observations on the 
hill varied more from each other on that day than on the 
other occasions : omitting the observations of the 18th of 
July, the mean barometrical result is 1640.5 feet. 
The following table exhibits a general view of the several 
determinations ; 
July 18. 
July 19. 
July 21. 
1630.66 
16354 
1641.7 or with + .196 1652.06 feet. 
Mean 1638.08 
From Station A Altitude of the Cone. 
Trigonometrical From Station C ... 
From the Observatory 
1642.9 
1640.6 
1644.6 
1630.7 
i 6 354 
1641.7 
1645 feet. 
c J’-iiy 17- 
Barometrical 
July 19. 
July 21. 
MDCCCXXIV. 
Rr 
