of a Hemisphere, &c, 313 
in terms of the cosine of the simple one, we have, for the 
equation of the curve brC. 
When n = i, V x *-\ -y = or x% +>" = tx, the equa- 
tion of a circle. 
When n = 2, v/x* y* = ~iy y i . — r or (a ; 2 -f- y ') 3 = r 9 
{x % —y'Y\ and in general the curve will be algebraic when » 
is any whole number. 
