While most of the early pioneering computer artists were scientists learning to manipulate the giant mainframe computers they worked on during the day, Henry was different and chose to work with analogue computers instead. During the 1950s he bought himself an old WW2 Sperry Co. bomb sight computer (widely known as the first true analogue computers) then set about modifying it into a sort of plotter.
By constantly finely adjusting the different dials and settings Henry was able to produce his fantastically expressionist artworks. Not a quick process, each drawing would take between 2 hours and several days to complete. His work is a genuine fusion between man and machine and he has commonly been called the Picasso of Mechanical Art. Unlike his digital programming counterparts whose work would be achieved with robotic uniformity (provided they got their codes right), Henry’s work was also somewhat ground-breaking as he actively accepted and integrated the element of uncertainty into his drawings. Tiny flexes or mis-adjustments could send the pen off in its own direction, and it is this spontaneity that makes Henry’s images so appealing and lively to the viewer.