| Description | Engine Designs by James Watt, Edward Bull and Jonathan Hornblower’s Engines, Dutch Windmill etc. (29 items).
1340. Double Reciprocating Engine, Soho Manufactory. Aug., Oct., Dec. 1782, Jan., May 1783, Apr. 1787. 30 items.
Double-acting rotative engine, with 18 inch cylinder, 22½ inch stroke, rack & sector connection, cast iron connecting rod, "internal" sun & planet gear.
Side view of the engine, marked "First drawing of small reciprocating engine, Aug. 1782."
Side view of the engine house and cross-section of round boiler, plan of the engine house and round boiler - 2 reverse drawings by James Watt, Oct. 1782.
Set of numbered reverse drawings, Dec. 1782, Jan. 1783:
No. 1 - Plan of upper working gear (partially coloured); No. 2 - Side view of upper working gear; No. 3 - Side view of lower working gear; No. 4 - Plan of lower working gear; No. 5 - Parts of the working gear of the lower exhaustion regulator; No. 6 - Parts of the working gear of the lower steam regulator; No. 7 - Parts of the upper exhaustion working gear; No. 7 - Parts of the upper steam regulating working gear; No. 9 - side view of the engine (coloured); No. 10 - end view of the engine; No. 11 - "Drawings made for fixing the fly" (end and side views of fly wheel).
Other drawings:
Plans and sections of nozzles - partially coloured reverse drawing, 1782; plan of the engine, Jan. 1783; plan of the engine - reverse drawing, Jan. 1783, showing different connection to machinery; diagrams and tables for steam and exhuastion regulators, Jan. 1783; views of the working gear, marked "…being various ways of equalizing the different powers of the pressures on the valves…", Jan. 1783; brasses for parts which connect the rod with the beam, Jan. 1783; plan and sections of the condenser - 3 coloured drawings; plan and sections of the cylinder and nozzles etc. - partially coloured reverse drawing; section of the cylinder - reverse drawing; upper and lower working gear - 2 reverse drawings, May 1783; rotative wheels, marked "There is another copy"; drawing of working gear marked "18 inch engine"; drawing of sockets or valves [?] marked "30 Apr. 1787 Double Reciprocating Engine".
Original Portfolio or 'Book' No. 29. Catalogue of Old Engines p. 338.
For Soho Manufactory / Boulton & Watt. This was the first double-acting engine made by Boulton & Watt. It was intially used to drive a corn mill at Soho Manufactory, but was later applied to power lathes and drills for the engine shops, and John Southern describes it in his list of books as the "boring engine". The rotative mechanism was the "internal" sun and planet gear, in which the sun wheel ran round the inside of the planet wheel. This mechanism was included in Watt's patent of 1781. According to the List of Engines made at Soho, the engine was first tried in Jun. 1783, but an entry in Watt's diary for 1783 quoted by Dickinson & Jenkins [p. 140] shows that the engine was at work in Mar. 1783. Dickinson & Jenkins also refer to Watt giving the stroke as 18 and 24 inches in various letters [p. 162]. According to the List of Engines made at Soho it was taken down and broken up in 1803. |