Poldice No. 1, Eastern, 1778—1780

Cornish Mine Engines (22 items).

1286. Poldice No. 1, Eastern. Sep., Nov., Dec. 1778, Mar., Jul. 1779, Dec. 1780. 22 items.
Single-acting engine, with 63 inch cylinder, 9 foot stroke, chain connection.

General drawings:
Two general views of the engine, one dated Dec. 1778; two plans of the engine house and boiler (these show different arrangements and neither is titled "Poldice"); cross-section of the boiler and engine house; longitudinal section of the engine house. None of these drawings are dated except for one of the general views. All are titled "Poldice" except the plans of the engine house and boiler.

Drawings of the working and injection gear:
Ground plan and front view of the plug tree and Y post; side view; side view and plan marked as being for Poldice and Wheal Chance - coloured drawings; side view and plan of upper working gear marked as being for Poldice and Wheal Chance - partially coloured drawing. None of these drawings are dated.

Other components:
Sections and plans of cylinder, condenser etc. - two copies, one dated Sep. 1778, the other marked "duplicate"; brass condenser - two copies, one dated Nov. 1778, the other partially coloured and dated Jul. 1779; balance bob, Mar. 1779; plan and section of cradle and bed for balance bob; section and plan of nozzle - two copies, one partially shaded; eduction pipe - two copies, one partially coloured and marked "duplicate"; clack seat pieces etc. for the pumps.
Also coloured drawing of "Lower Nozzle for a 63 inch cylinder", Dec. 1780 (this drawing may be for the second Poldice engine or another 63 inch engine, as this engine was at work by Dec. 1780).

Original Portfolio or 'Book' No. 1. Catalogue of Old Engines p. 300.

For Poldice Mine. This was the first engine for Poldice; it was ordered in 1778, but did not start work until 1780. According to the List of Engines made at Soho, it stopped in Aug 1795 and was sold to Wheal Treasury, where it was erected "upon Bull & Trevithick's syphonic construction." It was still at Wheal Treasury in May 1798, but according to Dickinson & Jenkins [p. 342] it was later sold to Wheal Sparrow.

See also: Engine Agreements.