| Description | Engine Designs by James Watt, Edward Bull and Jonathan Hornblower’s Engines, Dutch Windmill etc. (43 items).
1346. Sliding Valve Engine. Jan., Mar., May, Jun., Nov. 1783, Aug. 1793, circa Sep. 1799. 47 items.
Double-acting rotative engine, with 12 inch cylinder, trunk piston, 12 inch stroke.
Views of engine etc.:
Side and front view of engine with separate valves, direct connection between the beam and piston rod; side view and plan of engine with piston slide valve, rack and sector working gear, rack and sector connection; side view of engine with piston slide valve, rack and sector working gear (different to the previous drawing), rack and sector connection; section of piston and slide valve, with drawings of rotative motion on the same sheet; section, front view and plan of cylinder and slide valve; plan of engine house (? - v. poor drawing, a reverse copy?). None of these drawings are dated or bear titles.
Valves, working gear, nozzles etc.
Side view of two separate valves; side and front view of two separate valves and plug tree; "Drawing of a Sliding Regulator for a double reciprocating engine", Jan. 1783 - coloured drawing of D slide valve marked "J. S. [John Southern]" in pencil, with reverse copy; pencil sketch of a piston slide valve; sketch of a piston slide valve [Dickinson & Jenkins date this sketch to circa Jun. 1783]; sections and plans of piston and D slide valves; rack and sector working gear; 4 drawings of nozzles, valve boxes etc. All these drawings are untitled and undated unless otherwise noted.
Parts of engine, Mar., May, Jun. 1783:
Plan and sections of condenser - 3 reverse drawings; section and plans of cylinder - partially coloured reverse drawing; section of piston and piston rod - reverse drawing; rotative motion - reverse drawing; plan and section of piston slide valve - original and reverse drawings.
Drawings dated Nov. 1783:
Outline side view of the engine showing slide valve and direct connection between the beam and piston rod, front view and plan of the engine, sun & planet motion, section and side view and plan of slide valve - reverse drawings.
Set of drawings made Aug. 1793:
Side view of the engine, plan of the engine marked "For Fenton & Co. erected at Morriston", front view of the engine - reverse drawings. All these drawings bear letter codes. These drawings show an engine with a crank and drop valves, and are probably of the Soho Mint cutting-out engine.
Graphs and miscellaneous drawings etc.:
3 graphs for the working of valves and spirals [?]; miscellaneous drawings of slide valves, nozzles and unidentified machinery. None of these drawings are titled and none are marked "Book 40", so they may have originally been kept elsewhere.
Original Portfolio or 'Book' No. 40. Catalogue of Old Engines p. 338.
John Southern opened Book No. 40 in 1783 for drawings of an experimental sliding valve engine. According to the List of Engines made at Soho, the engine was erected in "The Temple" at Soho Manufactory for trials, and began work in 1785. However the dates on the drawings suggest that the engine may have been at work earlier. At around the same time Matthew Boulton erected a 12 inch engine for operating cutting-out machinery at the Soho Mint. According to the List of Engines made at Soho, the cutting-out engine began work in 1785 or 1786. It is not clear whether these two engines were identical - the experimental engine featured a trunk piston and appears to have had several different types of valve fitted to it, but the List of Engines made at Soho does not mention the cutting-out engine having sliding valves. According to the List of Engines made at Soho, the cutting-out engine was sold to Thomas Fenton & Co. of Morriston in 1793 or 1794, while the experimental engine was used as a compressed air engine for working pattern-makers' lathes at Soho Foundry in 1802.
Published references: Dickinson & Jenkins p. 162, 163, 190, 191, plates LX - sliding regulator Jan. 1783, LXI - slide valve Nov. 1793, Fig. 21 - sketch of piston slide valve. |