The 'sophistical' overbalanced wheel
A weight-driven wheel Leonardo brands a fallacy, with a bow-and-windlass device
The sheet is dominated by an overbalanced wheel: a hub carrying radiating arms, the longer arms ending in weights lettered b through i and the shorter arms carrying r q p o n m L K. In the accompanying note Leonardo works through the levers and counter-levers and marks the whole scheme 'soffistico' (sophistical), concluding that, since each descending weight is resisted by another, the weight f is left alone against the rest and the wheel cannot drive itself. At the lower left is a bow-armed device with a long stock and a windlass or lever, and small spiral figures appear at the foot of the page.
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An overbalanced wheel judged a fallacy
The center of gravity of the weights r q p o n m L K lies at n, so the lever nf must receive the counter-lever mn within itself twelve times. Because i resists the descent of c, h resists d, and g resists e, the weight f is left alone against the rest - and Leonardo marks the device 'soffistico', a sophistical scheme that will not turn of itself.
The radiating weight-arms of the wheel
Eight longer arms carry the weights lettered b, c, d, e, f, g, h, i, and shorter arms carry r, q, p, o, n, m, L, K. The weight b, sitting over the center of the wheel on the perpendicular line, counts for nothing in the power of motion.
Bow-armed device with stock and windlass
At the lower left is drawn a device with a curved bow, a long stock, and a windlass or lever resembling a spanning mechanism; a separate arc is sketched above it. No descriptive text accompanies these drawings in the bundle.