The effort of raising versus dragging a load
How dragging and wheels lessen the force needed to move a thousand-pound weight
This continuous note compares the force needed to move a heavy body by different means. Leonardo states that a thousand-pound load lifted straight up still weighs a thousand pounds to its mover, but dragging it cuts the effort by a third, and moving it on wheels reduces the effort further in proportion to the size and the multiplied number of the wheels. He adds that the same journey can be made with different amounts of time and power, the gain coming from multiplying the wheels on which the axles rest.
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Raising, dragging, and rolling a weight
A load of a thousand pounds, raised by simple pulling, still shows itself as a thousand pounds to its mover. Dragged along the ground it diminishes by one third, and moved on wheels it diminishes further by degrees. The same distance may be covered with differing quantities of time and power.
Wheels reduce the mover's effort
The reduction of effort grows with the size of the wheels and, further, with their number multiplied. In the same time and motion the gain is made only by the wheels on which the axles (poles) rest, when these are multiplied.