Pendulum-driven mill, a screw pump, and paired self-turning tanks
Figures 8-10 with a lettered overbalancing device (a-n)
Four mechanisms are laid out: three toothed wheels and a long pendulum driving a millstone (Fig. 8); the alternating motion of two long poles linked to threaded rods (Fig. 9); and an Archimedean screw raising water (Fig. 10). Below, a pair of rotating instruments tied together is lettered f, S, m, a, b, c, d, e, n; the long note describes how the left tank passes water through an inward-opening valve while air escapes, so that lead sitting above forces the water across and the paired tanks keep turning and exchanging their water. A block of mirror-script runs along the foot of the leaf.
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Figure 8: pendulum-and-gear drive for a millstone
Three toothed wheels combined with a long pendulum are arranged to drive a millstone (molino). The pendulum stores and returns motion to keep the mill turning steadily.
Figure 10: Archimedean screw raising water
A single Archimedean screw (coclea) is drawn as a water-raising device, fed from the water source. It complements the pumps and scoop wheels studied on the neighbouring folios.
Paired self-turning tanks (f, S, m, a-e, n)
The left tank sends its water from f into b through a valve that opens inward, while air escapes by a-n and the mouth a is set high so no water spills. When tank a-b-c fills, it turns over, the lead stays on top and presses the water across; once empty, the lead sinks and through m-S the tank receives water from the right, keeping both in motion.