t 11 ] 
A 
In which let the ellipfis ApBqA , whofe axes AB , 
pq , are in any given ratio, as of m to n , have the cir- 
cles apbq , and APB Q infcribed and circumfcribed 
to it : And if the figure revolves on the axis PQ 
there will be generated an oblate fpheroid ApBqA , 
with two fpheres, the greater circumfcribed to the 
fpheroid, and touching it in its equator APA , and 
the lefier infcribed and touching it in the poles pq ; 
the folid content of the fpheroid being the firfl of 
the two mean proportionals between the folidity of 
the exterior fphere, and that of the interior. 
But if the figure revolves on the axis AB , there 
will be generated a prolate fpheroid ApBqA , infcribed 
in the exterior fphere at the poles AtB ; and circum - 
feribing the interior fphere at the equator pqp , its fo- 
lidity being the fecond of the above mean proportion- 
B 2 als. 
