This is a model of a self propelled portable engine, AKA "Lokomobile". In real; life, they were an intermediate stage of development between the horse drawn portable and the traction engine.
The internal dimensions of the boiler are approx 120mm long x 55mm diameter, which is somewhat smaller than it looks from outside. It has a standard Wilesco style water level glass in the rear end, situated slightly higher than central. There is also a drain cock beside the glass. Fittings on the top of the boiler are a pressure gauge, safety valve, spring loaded whistle and a steam feed pipe with a regulator. Mounted on the forward end of the boiler are the engine bracket, a pillar carrying the dummy governor and a chimney.The chimney is hinged so that the top half can be folded down.
Steam is fed from the regulator to the under side of the steam chest on the double acting fixed cylinder. There is a small oiler on the top side of the steam chest. The cylinder is approx 13mm bore x 16mm stroke. The piston valve is operated by a slip eccentric on the crankshaft. Exhaust steam is fed forward to the dummy smoke box and hence to the chimney. The crankshaft has a 78mm diameter flywheel at each end, on one of which is fixed a double pulley and on the other a sprocket for the drive chain. The chain drive is in two stages with an intermediate shaft under the boiler.
The overall colour scheme is all black and brass. The firebox, engine frame, chimney, pressure gauge and wheel spokes are black, the rest being mostly brass or brass colour.