@LPdan Further to my previous novel: The mastering shaft traversing the full length (width) of each horizontal row had a continuous, full length, key way milled into it. Individual dimmers at 100% could be pre-rotated and locked.
Dimmers set less than full could be rotated and
preset to lock as their mastering shaft rotated, thus collecting / coralling them as it rotated past.
Similarly, Master handles for the horizontal rows could be locked and would likewise be captured by the Grand Master on its way to lower levels.
Sub mastering, or Grand Mastering, on the way up required more skill, practice, prayer and luck to individually unlock sub masters &/or individual dimmers on the way back up.
Skilled operators perfected various moves and choreographed dance routines involving wrists, forearms, elbows, ankles and knees.
When forearms were insufficient; four arms were added resulting in carefully rehearsed duets and trios involving wondrous (humorous) contortions which would definitely violate polite / social distancing conventions.
Toodleoo!
Ron (
Who, unfortunately, became too well acquainted with the sweaty BO of his seniors) Hebbard