Gravity, Resistance, and the Beginning of Motion
A body seems heavier the weaker its support, and how motion, like a line, begins at a point
Leonardo argues that gravity keeps as far as it can from lightness, and that a body appears heavier when held by a weaker resistance, which arises from the part most remote from the support's fixed point. The part a b is thus twice as strong as b c, being half as near the center of the support, while equally remote resistances are equal. Two pulley wheels hung with weights and a crossed-arm balance accompany the notes. A closing passage denies that weight m should descend merely because its line is straighter, reasoning that motion, like a line, must begin at a point and arises only because the weight overcomes a weak support.
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A body seems heavier the weaker its support
Gravity makes itself as remote as it can from lightness, and that body shows itself heavier which is sustained by a weaker resistance. That resistance is weaker which arises from a part more remote from the fixed point of its support.
Arm a b twice as strong as b c
The part a b is twice as strong as b c, being half nearer to the center of the support than b c is. Where two parts are equally remote from the support's fixed point, their resistances are equal.
Motion, like a line, begins at a point
Leonardo refuses to accept that weight m descends merely because its line is straighter than a b. Since motion is of the nature of a line and a line begins in a point, motion too begins in a point; it does not resolve on descent by reason of a curved line it has not yet known, but arises because the weight overcomes a weak support.
Pulley wheels bearing weights
Two wheels turning on axles carry cords with hanging weights, illustrating how a load is supported at differing distances from the wheel's center. A crossed-arm balance is drawn beneath them.