The windlass lever, suspended rods, and the machine of the air
A pulley equated to a lever; a hanging and a resting rod; why a thrown stone falls back
The upper part sets a windlass with a lever and cord lettered c, a, b: pulling the lever at c by the cord c b acts as if one turned the lever a b. At the left a rod is drawn hung from a suspension point and another resting on a support, opening a study of how bars are borne. A prose note describes the earth wrapped in its air as a 'terrestrial and worldly machine', in which a stone thrown upward falls back by the shortest path because air of itself sustains no body heavier than itself.
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The windlass lever equated to a pulley
A winch or windlass is drawn with a lever and cord lettered c, a, b. The note explains that pulling the lever of the windlass at c by the cord c b acts just as if one turned the lever a b.
A suspended rod and its hanging point
A rod is shown hung horizontally, its ends marked a and b, from a point called the 'suspension'. It opens the study of how a bar is borne when it hangs.
A resting rod and its support
A second rod rests upon a support (sostentaculo), lettered c, d and a, b. The diagram pairs with the suspended rod above to contrast hanging with resting.
The terrestrial machine of the air
A prose note calls the earth with its surrounding air a 'terrestrial and worldly machine'. A stone thrown up from it returns by the shortest way, because air of itself sustains no body heavier than itself.