| Description | Engine Designs by James Watt, Edward Bull and Jonathan Hornblower’s Engines, Dutch Windmill etc. (46 items).
1342. Balance Bobs and Printed Drawings. 1779, circa 1780-1781, Jul. 1795. 46 items.
Balance bobs for mines, and printed plates etc. of drawings of engines and parts.
Balance Bobs:
Plan and sections of cradle of balance bob for Poldice; plan and cross-section of cradle marked "belonging to model of Ale & Cakes balance bob"; coloured plan and side view of a balance bob cradle and bed; large unmarked side view of a balance bob and section of the cradle; small unmarked side view of a balance bob and plans and sections of the cradle.
Printed plates from "Directions for Erecting and Working the Newly-Invented Steam Engines":
Plate X - Plan and Section of the Lid or Cover of the Cylinder (5 plates); Plate XI - Plan and Section of the Piston (7 plates); Plate XII - Piston Rod Caps (2 plates); Plate XIII - Methods of Fixing Pipes, Ladder which determines the Opening of the Steam Regulator etc. (original drawing and 2 plates); Plate XIV - Air Pump, Hot Water Pump etc. (original drawing and 7 plates); Plate XV - Section of the Beam, King Post etc. (original drawing and 7 plates).
Four plates from Hall's New Encyclopedia, Jul. 1795 (also used for a reprint of Watt's 1782 patent):
Sun & planet pumping engine with rack and sector connection; sections of piston, views of air pump and condenser etc.; equalizing machinery and beams; beamless pumping engine with two wheels.
Other printed drawings:
Air pump and condenser; chain links and adjusting screw; piston rod caps, martingales etc.; plan of a beam; section and plan of nozzle (2 drawings); section and plan of nozzle (different to the previous nozzle drawing); cross-section of boiler. None of these drawings are titled or dated, and all are much larger than the plates for the "Directions…"
Original Portfolio or 'Book' No. 24. Catalogue of Old Engines p. 338.
John Southern opened Book 24 in 1781, and described it as being for "Balance Bobs and printed drawings". The book was described in the Drawing Office Index as being for "Balance bobs and prints". However Henry Hazleton misleadingly described it as containing "printed sheets of engine details" in the Catalogue of Old Engines. |