Free Fall and the Articulated Lever
Weight in perpendicular descent, and a lever strong one way and weak the other
On this folio Leonardo pairs two claims about falling weight: a body descending along a perpendicular line with uniform motion never changes its weight, whereas a freely falling body gains both velocity and weight at every part of its descent. He then introduces the 'disjointed' or articulated lever, which is strong in one direction and weak in the other. A drawing below shows a train of such articulated levers linked by toothed screw-rods, with small plumb-line and circle sketches at the margins.
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Uniform perpendicular descent versus free fall
No weight changes during its descent if it falls along a perpendicular line with uniform motion. But a weight that falls freely acquires, in every part of the descent, both increasing velocity and increasing weight.
The disjointed (articulated) lever
Leonardo announces the study of the articulated lever, which is strong when worked in one direction and weak when worked in the other. The drawing shows a chain of articulated levers coupled by toothed screw-rods.