BWG No. 1, Cadiz, Spain, 1791—1793

Vacuum and Blowing Engines (38 items).

Engine with 34 inch cylinder, 8 foot stroke, parallel motion.

Reverse drawings, Aug. 1791: plan of the engine and boilers and blowing apparatus, showing 6 furnaces arranged in a circle round a central 'blowing' or air vault which was fed by the blowing cylinder; general view of the engine, blowing cylinder and air vault (with a sketch of the Donnington Wood blowing cylinder on the back).
Reverse drawings, Jan. 1792 (not showing the blowing cylinder or air vault): front view and general view of the engine only (with original drawing); ground plan of the engine; plan of the cylinder and boiler tops
Reverse drawings, Feb. 1792: general view of the engine, blowing cylinder and air vault; ground plan of the engine, boiler, blowing cylinder and air vault; cross-section of the boiler and outside view of the chimney; front view of the engine and longitudinal section of the boiler; plan of the tops of the cylinder, boiler, blowing cylinder and air vault; outside view of the engine house and boiler; outside front view of the engine; cross-section of the boiler and seating through the uptake; plan of the main beam and spring beams.
Drawings, Feb. 1793: plan of the engine and boilers , blowing cylinder, air vault and 6 furnaces; general view of the engine, blowing cylinder and air vault (these drawings are simlar to those done in Aug. 1791 and are referred to by the "Reference to Drawings" manuscript below).
Coloured original and reverse drawings of second boiler and seating, Jul. 1793: plan, plan of the top and steam pipe, sections showing seating, feed apparatus and chimney, longitudinal section.
Blowing cylinder pipes; plans and sections of the blowing cylinder - original and reverse drawings, and sheet marked "Cylinder for Mr. Low"; parallel motion - partially coloured reverse drawing; working gear - partially coloured front and side views; small sheet of drawings of various pipes; valves, regulating air cocks - reverse drawings; injection gear - side and front views and plan. All these drawings bear letter codes.
Also the following uncoded items: small sketch of steam pipe for the second boiler; plans and sections of the old iron boiler, new iron boiler and copper boiler; coloured plan showing 4 furnaces, pipes and throttle valves.
Also "Reference to Drawings" - press copy of manuscript sent with the original drawings, Mar. 1793, comprising the following parts: "Reference to the Drawings" (2 unumbered pages with key to the Feb. 1793 drawings); "Remarks upon the Drawings with directions for working the Blowing Engine BWG No. 1 for Messrs. Fermin de Tastet & Co." (pages 1-29); pages 30-32 left blank; "General Rules, Cautions & Directions (pages 33-37). A manuscript page 37 and 38 in Watt's hand has been inserted after the press copy pages.

Original Portfolio or 'Book' No. 159. Catalogue of Old Engines p. 268.

For Cadiz, Spain, ordered by Don Diego Gardoqui through Fermin de Tastet & Co. of London. The List of Engines made at Soho says that this was a 50 horse engine, but the Catalogue of Old Engines gives the nominal horse power as 49.2. It was usually referred to in the firm's records as "BWG", which may have stood for "Boulton & Watt - Gardoqui".

See also: Incoming Correspondence.