Eight Pulleys on a Beam: Doubling of Power Along a Cord
A row of eight wheels with seven 4-pound weights, plus smaller pulley diagrams
Across the top a horizontal beam carries eight small pulleys threaded by a single cord, with seven square weights (each marked 4) hanging below. Leonardo states that a cord doubles its natural power as many times as it is supported at different points along its length. Below the text are several smaller pulley studies, one repeating the doubling series 64, 32, 16, 8 with the total 116, others noting simpler 4-and-8 pound balances.
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A cord multiplies its power at each support
The cord will double its natural power as many times as it is supported in different parts of its length. The top row shows one cord over eight wheels carrying seven 4-pound weights, illustrating how repeated supports multiply the effect. The lower stack repeats the doubling 64, 32, 16, 8 summing toward 116.
Number labels on the small pulley studies
The subsidiary diagrams are annotated with their loads: pairs reading 4 and 4 making 8, and a quadruple stack running 64, 32, 16, 8 down to 4 with the figure 116. The numbers track how each cord segment accumulates weight.