Henry's drawing machines produced abstract, curvilinear, repetitive line drawings compared to natural form mathematics produced using pendulum harmonographs and ornamental geometric lathes.

The chance element inherent in the construction and function of each Henry drawing machine ensured the unrepeatable quality of their infinitely varied visual effects. The aesthetic appeal of these 'mechanical fractals' lies in their unique blend of order and chaos, of regularity and irregularity.

Today not one drawing machine remains intact.