Studies of Wheels, Levers and Weights on Suspended Rods
Statics of balances, a hub moved by one-fifth its load, and where a weight presses
A crowded sheet of statics and mechanism studies. Diagrams of a wheel and its hub, a pincer-shaped instrument, and many rods hung from cords or resting on supports are annotated with weights, while the argument marked b n a demonstrates that a weight of 6 presses equally on the pole whether placed at n or m because it lies five times nearer the pole than to the arm a b. A wheel loaded with 500 pounds, one note observes, will be moved by 100 pounds of force. A small figure in the upper-left corner ties the sun's position to June, September and December.
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A wheel moved by one-fifth of its load
Beside a drawing of a wheel and hub Leonardo writes '500 - 100': this wheel, loaded with 500 pounds, will be set in motion by only 100 pounds of applied force. A companion note on the hub instructs one to measure the axle (pole) at a n where it has various thicknesses.
A weight presses the pole equally whether at n or m
By the figures b n a Leonardo wants to prove that the pole a bears as much of the weight 6 when that weight is at n as when it is at m above, because the 6 always lies five times nearer the pole n or m than to a d or a b.
Proportional distance on a rod hung from two cords
A rod is suspended from two cords and marked 1 6 - d c m - 16. The note reasons that 6 is nearer to 5 - five times nearer - than 1 is, fixing how the load divides between the supports.