Except for the remarkable "
Blue Balls" pictures of the early '60s (which were "inspired," as it were, by another illness, this time renal tuberculosis, which painfully swelled and discolored Francis's eponymous testicles), his paintings started to look like an ongoing technique applied to large or small formats, depending on what the market would bear, and varied in configuration (the almost-vacant "Edge" paintings, 1966-69, the transparent wet grids corralling his liquid primaries, the snaky-patterned pictures done more or less the same way, and so on) according to the influence of the moment (Minimalism, a Jungian therapist).
At the countdown, the tree factory, or "solar green machine," showed the workings of a tree by spraying out water (evapotranspiration) and inhaling red balls (representing carbon dioxide) and exhaling
blue balls (oxygen).