C 4n ) 
Ltt A p E P be the Earth covered over with very 
deep Warers, C its Center, P, p, its Poles, A E the 
iiquincftial, /^/ the parallel of Latitude of a place, 
iP ^ another Parallel at equal diftance on the other fide 
of the /Equiao&kU H h the two Points where the 
Moon is vertical, and let A' it be the great Circle, where- 
in the Moon appears Horizontal. It is evident, that a 
Spheroid defcribed upon Hh.zod Kk (hall nearly repre- 
fent the Figure of the Sea, and Cf^ CD, C F, C (hail 
be the hights of the Sea in the places /, D, F, in all 
which it is High-water : and feeing that in twelve Hours 
time, by the diurnal Rotation of the Earth, the point 
F is transferred to /j and J to D : the hight of the Sea 
C F will be that of the High-water when the Moon is 
prefent, and Cf that of the other High water, when 
the Moon is under the Earth : which in the cafe of this 
Figure is lefs than the former C P. And in the oppo- 
fite Parallel D d the contrary happens* The Rifing of 
the Water being always alternately greater and lefs in 
each place, when it is produced by the Moon declining 
fenfibly from the itquinodial ; that being the greateft 
of the two High-waters in each diurnal Revolution of 
Y y y the 
