Screw devices, a leather-bound tripod, and a hollow-sphere note
Small mechanical sketches drawn with the sheet inverted
Drawn with the sheet turned upside down, this leaf gathers a scatter of small mechanical studies: screw mechanisms said to push on the outward stroke and to pull or hold on the return, a tripod whose three staves are bound together with leather, and a brief note on making a hollow sphere. Clamp-like fittings, a spiral coil, and a helical screw are sketched among them. Additional faint sketches and further untranscribed lines of mirror-writing appear across the sheet.
On this page
A screw that pushes and pulls
A crossing-of-channels detail is labelled the manner of the screw: it drives forward and draws back as it turns. A companion figure is said to push on the outward stroke and to hold on the return, describing a reciprocating threaded action.
Reciprocating action: outward push, return hold
An analogous figure is noted to push while going and to sustain on the return, distinguishing the working and idle phases of the mechanism's stroke.
Tripod with three staves joined by leather
A tripod is annotated 'leather,' and a small figure is captioned as the piece that joins the three staves together, i.e., the leather binding that gathers the three legs at their meeting point.
Note toward making a hollow sphere
A device at the right, drawn with the page inverted, carries the opening words of an instruction for making a hollow (concave) sphere; the note breaks off unfinished.