The larger drawing 'A' depicts a carpentry framed engine after an engraving in Stephen Switzer's An introduction to the general system of Hydrostaticks and Hydraulicks (1729). The detail of the valve-gear, depicted on the smaller drawing, is incorporated as an inset in the engraving. With ink and colour wash drawing 'B', 26.5x33.5cm, drawn after the engraving by Sutton Nicholls of 1725 and published in 1726 prior to the completion of the engine for the waterworks which it purports to show. Actually, the general lay-out of the subject has close parallels with Beighton's engraving of a colliery engine at Griff, published in 1717. [Nicholls' adaptation of Beighton's print indicates design improvements between 1717 and 1725]. With also a "Description [re drawing 'B'] d'une machine hidraulique pour Elever l'eau par le moyen du feu"