The Centre of Gravity of the Earth , [August, 
446 
to differ considerably at intervals of six months, and from 
no other cause than that the centre of gravity of the Earth 
does dot coincide with the true centre of the Earth. The 
amount in minutes and seconds of arc due to this position 
of the centre of gravity of the Earth can now be demon- 
strated. 
From an investigation of the relative arrangement of land 
and water on the surface of the Earth, I have concluded 
Diagram 2. 
that the centre of gravity of the Earth is 2100 feet from the 
axis joining the two poles, which two poles are equidistant 
from all parts of the Equator. A second of latitude may 
be taken as equal to 101 feet on the Earth’s surface ; conse- 
quently 2100 feet may be taken as about 2o"'j. It follows, 
therefore, that a plumb-line at the Poles directed towards 
the centre of gravity of the Earth would form an angle of 
20 "7 with an axis joining the two poles. Consequently the 
