Model, rotative beam engine, c. 1805, scale 1:8, made by William Tongue, an apprentice with Boulton & Watt from 1797 until 1804. It represents the rotative steam engine as Watt left it upon the expiry of his patents in 1800. Cast iron has replaced timber in the main engine components, and the sun & planet gear has been replaced by a more straightforward crank. The nozzles (valve boxes that controlled the inlet and exhaust of steam at each end of the cylinder) each contain two concentric socket valves of the type introduced by William Murdock after 1800. The eccentric driving the valves was also his improvement.
- Motive Power
- Object Number:
- brass (copper, zinc alloy), complete, copper (metal), iron, ivory, mahogany (wood), paint, steel (metal) and wood (unidentified)
overall (including mahogany stand): 800 mm x 800 mm x 370 mm, 27kg
- steam engine
- Osman, M.H.