1851 Great Exhibition: Official Catalogue: Class V.: John Penn and Son
8. PENN, JOHN, and SON, Greenwich — Manufacturers.
Pair of marine oscillating engines. One paddle-wheel is fitted on the patent feathering principle; and the other on the ordinary plan. Collective power, 24 horses.
Pair of patent marine engines on the trunk principle, arranged and adapted for the driving of the screw-propeller direct. Collective power, 60 horses.
Fig. 1 represents a section of the patent marine trunk engines, the piston being at half stroke.
Fig. 2 shows a section of the marine oscillating engines at the air-pump.
Working model of a pair of marine oscillating engines, as made and fitted on board H.M. steam-frigate "Sphynx." Collective power, 500 horses.
Working model of a pair of oscillating engines, used in river vessels.
Working model of a pair of patent trunk engines, as fitted on board H.M. steam-frigate "Arrogant," 46 guns, and H.M. steam-sloop "Encounter," 12 guns. Collective power, 360 horses.
An auxiliary or " donkey" engine for pumping water into marine boilers when the larger engine is not at work.