Wear of a pivot; a stage-mountain that opens
Which wears more, wheel or support; and a mountain machine opening to reveal Pluto's Hell.
In transmitted light this leaf (231v, the reverse of the mechanical studies) shows the same repertory of beams, trusses, levers and rollers in mirror image, with an arched structure at the lower left. One lettered note weighs which wears more - a wheel turning with its hole on a fixed pole, or the support carrying a movable pole and its wheel - concluding that the support wears more because it bears both wheel and pole. A second passage designs a stage 'mountain that opens': the segment a b moves into c d and c d into e f to reveal Pluto in g, his dwelling, whereupon devils sound twelve pots as infernal voices amid Death, the Furies, Cerberus, weeping naked children and fires of various colours.
On this page
Which wears more, the wheel or its support
Leonardo asks whether more is worn away by the wheel turning with its hole on the immovable pole, or by the support that holds the movable pole together with its wheel. He answers that the support wears more, because it sustains both wheel and pole, while the pole sustains only the wheel.
A mountain that opens in segments a b, c d, e f
The stage machine a b c d is a mountain that opens: a b moves into c d, and c d into e f, so that Pluto is disclosed in g, his residence. The lettered scheme describes the sliding segments of the set.
Pluto's Hell revealed, with devils and Furies
When Pluto's paradise opens, devils are to sound twelve pots as infernal voices; here are Death, the Furies, Cerberus and many naked weeping children, with fires made of various colours. A marginal note beside a figure reads that 'here one is clothed'.