616 ON THE FIGURE, DIMENSIONS, AND MEAN SPECIFIC GRAVITY OF THE EARTH, 
north and to the east, and if we put | and yj for the same quantities at Greenwich, 
from which point the calculations of latitude and longitude and azimuths had their 
commencement, then each point at which the latitude has been observed will give an 
equation of the form 
f „ = a + ^1+ c;j + mla -\-n6e, 
and each point at which the longitude or direction of the meridian has been deter- 
mined will give an equation of the form 
=a! c'ri -j- m!^a -\-n''he, 
in which la and are the increments to the semiaxis major and eccentricity of the 
spheroid (A). 
In consequence of the smallness of the coefficients nni m the latitude of Great 
Britain, the quantity le would have very little weight as determined from these equa- 
tions. 
Surface of Great Britain. 
The approximate results derived from the above equations are, assuming ^e=0, 
Sa=2536 
=0 
I = + l"-4, 
so that the semiaxes of the spheroid most nearly representing the surface of Great 
Britain are 
a=20926249] 
>feet of Ordnance Standard O,. 
6=20856337] 
a — b 1 
a “299-33 
Most probable Deflections. 
The last column of the following Table contains the most probable deflections at 
the various stations as resulting from a comparison of the actual observed latitudes 
with those of spheroid (B), or of the apparetit and mean latitudes. 
