細節
An exhibition standard 1/12th scale model of a McNaught compound condensing side lever rotative beam engine, originally built for J. Fergus, Prinlaw Mills in Leslie by J. & G. Thomson, Clyde Bank Foundry,
and modelled by A. Walshaw, with brass-bound and wood-lagged cylinders 1¾ and 2½in. bores x 2in. stroke, inward facing and truncated valve chests, the valves operated from a single eccentric and lift-off rod, cranks and rods, the pistons with shaped crossheads, barrelled connecting rods with wedged and cottered big ends with split brasses and shaped oil pots incorporated in the little ends, cast beams pivoted from the central engine frame and air pump driven from from both beams via connecting rods and a yoke crosshead. Further details include inlet pipe with wood lagging, main stop and governor valves, transfer pipe, the overmounted tapered crankshaft supported in three main bearings, two trunnions mounted on tapered columns, the third supported on the "engine house" wall, gear driven Watt type governor and linkage, webbed crank and spoked flywheel, finished in blue, black, red and polished brightwork and mounted on wooden bearers on a slate floor with wooden hand rails with delicately pierced supports, wood base and perspex cover -- 59 x 68cm. (23¼ x 26¾in.)
See Illustration