Persistence, moving

One operation, a swept pass, runs over the canvas many times along nearly the same trajectory. Every cell of a fixed sixty-four square register counts how many passes reached it, and the finished image is that count, drawn: cells reached once carry a single thin bar, cells reached a few times carry ruling, cells reached by every pass are solid and heaviest. The sweeper itself is never drawn. Underneath is a chronology: a ring system, then quiet strata that buried it, then the passes. Where the passes scoured the strata thin the ring system comes back at full strength, not as a ghost; where they hit hardest it is gone entirely under the record.

Of the pieces in the gallery this is the one whose subject was already time, so it is the one that had the least to be given. The trajectory drifts, and the record is rewritten continuously: the band writhes, old ground is uncovered where the passes leave and buried where they arrive, and the fan opens and closes on the beat. The count is always of a full fifteen passes, so this is a duration being revised rather than a register filling up, and the frame at rest is the published picture.