Two Weights on a Compound Pulley Block
Multiplying force by the number of sheaves in the tackle
Drawings of two weights hung from cords running over pulleys, with a compound pulley block (tackle) at the left and simpler pulley arrangements at the right, labelled a b and 1 4 - m n. Leonardo states the rule that multiplying the weight m by the number of sheaves in the pulley-blocks gives the weight required at m to resist the weight n. A second note, breaking off, begins to relate the effect to the distance between the two cords that turn together.
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Force in a tackle equals weight times number of sheaves
Multiply the weight m by the number of sheaves of the pulley-blocks and you obtain the weight required at m to resist the weight n. This states the mechanical advantage of a compound pulley system.
Compound pulley block and simple pulleys
At the left a compound pulley block stacks several sheaves in a long frame carrying two weights; at the right, simpler single-pulley arrangements on a stand are drawn for comparison.