Percussion of compressible elements; lifting screws and pumps
Notes on the screw that must pull, and a piston fitted to a pump
On blue paper Leonardo opens with the percussion of the flexible or compressible elements, stating that they can condense without limit. Among many mechanical sketches, including a screw jack on a splayed tripod and press-like frames, he notes that a screw used to lift weights must always pull and never push. In the lower right corner a piston is drawn in section with the labels b, d, c, a, and a rule that the plunger rod must be equal to or smaller than the tongue of the pump.
On this page
Screw instrument for lifting weights
A note beside the mechanisms states that the screw used to raise weights must always pull and never push. The tall screw set on a splayed tripod illustrates such a lifting screw.
Piston fitted to a pump, in section
In the lower right corner a piston is shown in section with the labels b, d, c, a. Leonardo notes that the plunger rod must always be equal to or smaller than the tongue of the pump and its bore.
Percussion of compressible elements
The opening line treats the percussion of the flexible elements, asserting that the compressible elements have the capacity to condense infinitely. This frames the mechanical studies as questions of impact and compression.