MEAN DENSITY OP THE EARTH. 
375 
space inside the 10 mile limit is also to be conceived as 
divided by concentric circles whose radii have the same 
geometric relation to each other, hut which are not drawn 
in the figure to avoid complicating the diagram, since start¬ 
ing with a radius of one mile and increasing in this ratio 
we should have the eighth circle, where for the arithmetical 
division we now have the second. The 10 mile limit above 
chosen includes the crater, the highest peak of the mountain 
(Kolekole) and the pendulum station at Pakaoao. The sec¬ 
tors count from left to right and are designated by Roman 
numerals. The radii are indicated by Arabic figures and 
increase from within outward. The compartment in sector 
I and between radii 1 and 2 may be written thus, If, and so 
on for others, so that the ring between these radii would be 
If + Ilf + Illf..XlXf 
The next ring would be 
If + Ilf + Illf.XlXf 
and so on. The compartment heights are given in the fol¬ 
lowing tables, pages 376 and 377. 
The attraction of compartment Ilf by formula (8) would 
be 
F=Jc3X 0.0189 X i*o X [jVop. log (1.12 + VTlW + 0. 0189 2 ) — 
Nap. log (1.02 + VTM 1 + 0Xfi!F)~] ’ (11) 
all distances being taken in miles. If we take a mean height 
for the entire ring between circles 1 and 2, we have 0.075 
miles and the attraction for the ring would be given by using 
this value for the height and multiplying the result by the 
number of compartments. The table on page 378 gives the 
computation in condensed form. 
