Loom mechanism: warp beams, reed and levers
Gearing of two warp beams, treadle-and-reed timing, and a note on aerial perspective
A cream sheet crowded with mechanical studies for a weaving loom. Two connected warp beams (subbi) are geared with equal numbers of teeth, the take-up beam made thicker so that as the finished cloth shortens it winds seven-eighths of a braccio for each braccio the other unwinds. Further notes and figures set out the timing of treadle (calcula) and reed (pettine), and a tooth-and-lever escapement a b / m n that alternately releases and engages side levers. A note at the foot observes that objects seen in fog appear larger, since only the perspectives of colour and outline change, not that of magnitude; a short column of numbers stands at the left.
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Two connected warp beams geared in a 7/8 ratio
Because beam a gathers the finished, shortened cloth, it must be geared to beam b, which is made thicker, their teeth equal in number so each makes the same number of turns. When beam b unwinds one braccio of thread, beam a winds up seven-eighths of a braccio.
Timing of shuttle-race and reed
While the race pulls without turning, the reed must beat; when the race slackens and returns backward without turning, the reed must return to its starting place. A companion note adds that when the treadle beats it must strike something that stops the beam.
Tooth-and-lever escapement a b / m n
The tooth a is raised by the cam of its channel, and in rising the fork n releases the lever n m so that b a moves until it drives the reed's stroke. The front n stays locked until the reed has struck, then on the return of b a it is unlocked and carried to repeat the action on the opposite side.
A lever set between two side levers
A central lever is placed between two other levers so that, moving from one side to the other, it leaves one side lever and takes the other, and on returning leaves the second and brings the first back with it.
Objects seen in fog appear larger
Things seen in fog or a dark medium appear larger than in clear thin air. The perspective of magnitude is not lost, but the two other perspectives vary greatly: one alters the true colours of bodies, the other the recognition of their outlines and the particles of which they are composed.
Column of figures
A short column of numbers set to the left of the mechanical figures: 45, then 13 and 4, 3 and 8, 3 8, 1 8, and 8.