Studies on the balance, power, motion and impetus
Draft propositions for a book on weights, tested with balances and double-groove pulleys
Across four columns Leonardo drafts numbered propositions toward a treatise on weights and motion, illustrated with balances, hanging weights, a spiral wheel and double-groove pulleys. He argues that a balance's pans falsify the true motion of a body in air, that a body freely descending gains velocity at every degree of motion, and that halving the power halves neither time nor space in simple proportion. The final column develops the idea of impetus as born from a wave the moving body makes in the air, asking whether the wave or the body travels farther and why a single impact makes several circular waves. Further faint text and diagrams remain untranscribed.
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True weights on a balance
For the true value of weights, the balance must carry simple weights of equal shape, because the pans falsify the true motion a body would make in air. Leonardo marks this a 'beginning of the book.'
Weakest part of a support
Beside a double-groove pulley he notes that the part of a support situated farther from its fastening will be the weaker.
Infinite power lifts infinite weight
A balance scheme labelled b a states that where there is infinite proportion of power against its resistance, infinite weight will be lifted, with a fragmentary remark on a point so far below the fulcrum that it raises b.
Power, body, space and time
If a power moves a body a given space in a given time, the same power moves half that body over all that space in half the time, or over twice the space in all the time.
Curved paths and failed experiments
Two unequal weights on ropes would move as far as the ropes are long, but the balance does not, since the simple wheel, moving its weights along curved lines about its pole, soon halts. He judges the experiments useless because the balance gains velocity or slowness at every degree of motion.
Free descent, impetus and waves in air
A freely descending thing gains degrees of velocity at every degree of motion, and impetus is greater downward. Impetus is said to be born from the wave the body's percussion makes in the air, prompting the questions of whether wave or body travels farther and why one impact makes several circular waves.