Statics of Beams: Levity, Gravity and the Pulley
A beam raised at one end, cords lifting loads at right angles, and cranes with hanging weights.
Pen studies in the statics of beams. Leonardo states that a beam resting flat loads every part equally, but that once one end is raised, each degree of motion gives levity to that end and gravity to the opposite one. He adds that a cord meeting the beam at a right angle transmits the beam's true weight, less the counter-lever of the pivot. Around the text are many small diagrams of beams, cranes and pulleys lifting weights, together with a circle on a rectangle crossed by secant lines.
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A beam resting flat versus raised at one end
A beam lying evenly on its plane loads every part of it equally. But if it is raised at only one extremity while the opposite end stays fixed, every degree of motion gives degrees of levity to that part, so that each degree of motion yields levity at one end and gravity at its opposite.
Cord lifting a beam at a right angle
If the cord that raises the beam from one of its ends joins it at a right angle, it receives in every part of itself the true weight the beam gives it, after deducting the counter-lever of its pivot. The figure of the pulley and two beams is lettered p, o, 18, n, m.
Cranes and pulleys lifting weights
The upper part of the sheet is filled with small mechanisms: jib cranes, pulley blocks and cords from which weights hang. They translate the abstract beam-statics into practical lifting gear.
Circle on a rectangle with secant lines
A circle set on a rectangle is crossed by cutting (secant) lines and lettered b, c, m, o, d, r, t, S, e, n, a, f. The note marks it as 'copied'.