Experiment on thick vs. thin fulcrums and ease of motion
A weighted balance-arm and a framed pulley test how axle thickness affects movement
Two experimental diagrams test how the thickness of a fulcrum or axle affects how easily a load moves. At left a balance-arm carries a hanging weight marked 100; at right a weight marked 2 sits within a hatched vertical frame above a pulley, its cord lifting a small weight marked 1 below the ground line. The note concludes that the thinner the axle (the 'pole') of a cart, the more easily its motion is achieved.
On this page
A thinner axle makes motion easier
The trials set out to prove how thick or thin fulcrums behave, one pitting the values 5 against 1 and the other marking 100. Leonardo concludes that the thinner the 'pole' (axle) of a cart, the more easily its motion is made, a statement of reduced friction at a slender pivot.
Framed pulley lifting a hanging weight
At right a weight labelled 2 rests inside a hatched vertical frame set over a pulley, its cord descending past the base line to a small weight labelled 1. At left a graduated balance-arm carries a rounded weight marked 100 on a cord.