Wheal Virgin Double (Wheal Maid Double), 1786, 1787

Cornish Mine Engines (11 items).

1281. Wheal Virgin Double (Wheal Maid Double). Dec. 1786, Feb. 1787. 11 items.
Double-acting engine, with 63 inch cylinder, 9 foot stroke, parallel motion, unequal beam, separate air pump beam.

Set of numbered reverse drawings dated 11 Dec. 1786:
No. 1 - general view of the engine ("No. 1" has been crossed out); No. 2 - plan of the engine and boiler; No. 3 - cross-section of the boiler, plan of spring beams, section of pump rod and motion; No. 4 - parallel motion and connection to pump rod; No. 5 - front view of parallel motion and plan of condenser pump beam.

Also sections of nozzles; steam and catch pipes; boiler steam pipe; 3 sheets of calculations.

Original Portfolio or 'Book' No. 83. Catalogue of Old Engines p. 302.

For Consolidated Mines. Wheal Virgin and Wheal Maid were both part of Consolidated Mines, formed in 1782. This engine was referred to both as the "Wheal Virgin Double" and the "Wheal Maid Double". This was the only double-acting engine erected in Cornwall with a 63 inch cylinder.