ON CONOIDS AND SPHEROIDS 
59 
,he area of 
equilateral 
I compared 
which are 
the double 
le polygons 
ion is then 
>n an ellipse 
mdicular to 
t, (1) in the 
in the case 
ue) circular 
section of it, 
lions of the 
mference of 
the circular 
face passing- 
re G, where 
and perpen 
dar to that 
conoids and 
le respective 
the sections 
fferent ways 
-•h the centre 
t* to the axis, 
reference to 
j of parallel 
•eal business 
! the volume 
»ids and the 
1 inscribe to 
)r ‘ frusta of 
as we please 
nd inscribed 
o coincidence 
them. 
lane through 
to the plane 
of the section which is the base of the segment, and which 
is a circle or an ellipse according as the said base is or is not 
at right angles to the axis; the plane of the paper cuts the 
base in a diameter of the circle or an axis of the ellipse as 
the case may be. 
The nature of the inscribed and circumscribed figures will 
be seen from the above figures showing segments of a para 
boloid, a hyperboloid and a spheroid respectively, cut off