In article ,
"Smarty" wrote:
I am reminded of the challenge I was once given by an English teacher:

Describe in writing a helix without using either a drawing or your hands to
illustrate......

Hexix: A curve described by the parametric equation

x = cos(t)
y = sin(t)
z = t

where t ranges over the real numbers, or any curve that results from a
rotation, translation, reflection, or change of scale of another helix.

--
--Tim Smith