Measurement of three Degrees of the Meridian . 341 
by Svanberg, we have the entire arc measured equal to i° 
34' 55", 896 ; so that the difference between the results of cal- 
culation and of the observations, is only o",532 for the whole 
arc, or o' 7 , 337 for the mean degree. The elliptic hypothesis 
and observation agree more correctly in this instance, for the 
difference is rather less than in that of Lapland, although the 
two arcs are very nearly of the same extent. Thus the de- 
gree on the meridian measured in Bengal, in the latitude of 
2 2 0 32' 21" north, cannot be supposed to exceed Major Lamb- 
ton's estimate by more than 5,22 toises ; and it is extremely 
difficult to speak with certainty to quantities so small as this. 
The same observer also measured one degree perpendicu- 
lar to the meridian, by means of a large side of one of his 
triangles cutting the meridian nearly at right angles, and of 
which he observed the azimuth at the two extremities. The 
data from which his results may be verified are these : 
Length of the chord of the long side in English feet AB = 
291197,20. 
Azimuth of the eastern extremity A equal to 87° o' 7", 54 
NW. 
Azimuth of the western extremity B equal to 267° 10' 44", 07 
NW. 
North latitude of A 12 0 32' 1 2", 2 7 
North latitude of B 1 2 0 34' 38", 86. 
With these data in the triangle formed by the long side, 
the meridian at B, and the perpendicular from B on the meri- 
dian at A, we have the chord of this last arc equal to 290845,8 
feet, and the arc itself 290848,03 feet. By applying the me- 
thod of M. Delambre, we find the azimuth of the extremity 
B less by 2" than it was observed to be ; so that we have no 
Yy 
MDCCCXII. 
