What is a harmnograph?

Question

yes i meant harmonograph

Answer 1

The simplest form of a harmonograph uses two pendulums to draw geometric designs.  The pendulums are suspended through holes in a table.  The shaft of one pendulum carries a platform with a piece of paper on it.  The shaft of the other pendulum carries a pen.  One pendulum moves the pen back and forth while the other moves the surface back and forth along a perpendicular axis and a drawing is created as a result of their combined movements.  This is known as the "lateral harmonograph".

There is also a "rotary harmonograph" which uses three pendulums.  In these harmonographs, two pendulums are connected to the pen instead of one.  While the two still move at right angles to each other, the third pendulum, connected to the paper, moves in circles.  

Answer 2

Assuming you meant "Harmonograph", it's a device like a Spirograph, which uses occillating motion to draw complex curves