Mathematical Experiment 5

Construct the spiral as thus:
The stereographic projection from the xy plane to the unit sphere is given by
f(x,y) = 
Select a circle C orthogonal to the unit circle in the xy plane. Construct the surface formed by the line segments connecting points on C to the corresponding stereographic images.
Construct three cylinders with any two touching at one point. 
Construct one-half of the tangent cone to a sphere. 
Construct one-half of a right solid cylinder whose boundary consists of the helicoid, part of the cylinder and two semi-disks. 
Construct the cyclide by inverting a torus.