Water-Lifting Machines: Piston Pumps, Air Pump, Screw
Figures 23-25: paired alternating piston pumps, a compressed-air pump, and a crank-driven screw
Three machine studies numbered 23, 24 and 25 fill the sheet, each captioned only by a figure number and a short descriptive title. At upper left a pair of piston pumps works with alternating motion above two cylinders; at upper right a scaffolded compressed-air pump with a U-tube; and across the lower half a large tilted screw (coclea) said to be eight braccia long, turned by a cranked toothed wheel. The drawings are devices for raising water, sketched rapidly in ink with no continuous prose.
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Pair of piston pumps with alternating motion (fig. 23)
The upper-left mechanism is captioned as a pair of piston pumps working with reciprocating motion. A rocking beam suspended from above drives two cylinders set side by side, so that one piston rises as the other descends.
Compressed-air pump (fig. 24)
The upper-right figure is titled a compressed-air pump. A tall framework carries a piston above a cylinder joined to a U-shaped tube, the arrangement by which trapped air is used to move the water.
Cranked wheel driving a large screw of 8 braccia (fig. 25)
The lower figure shows a large tilted screw whose caption states that a toothed wheel turned by cranks drives it, and that the screw measures 8 braccia. It is drawn as a broad cylindrical body lying across an inclined support.