III. PRIME MOVERS. 459 



by the London and North-western Railway Company. The following 

 dimensions of them may be interesting : 



Dignity. Impudence. 



Size of cylinders - - 17| in. x 24 in. 4| in. x 6 in. 



Diameter of driving wheels - 8 ft. 6 in. 15 inches. 



Gauge - - - 4ft. 8^ in. 18 inches. 



Weight in working order - - 28^ tons 2 tons. 



2212h. Six Wheels coupled Mineral Engine. Size of 

 cylinders, 17" dia., 24" stroke. Diameter of wheels, 4 ft. 3 in. 

 Total weight in working order, 29 tons 11 cwt. F. W. Webb. 



The barrel of the boiler and fire-box casing are of steel, and the axles and 

 many of the working parts are also of steel. 



22121. Four Wheels coupled heavy Express Passenger 

 Engines. Size of cylinders, 17" diameter, 24" stroke. Diameter 

 of coupled wheels, 6 ft. 6 in. Total weight in working order, 

 32 tons, 15 cwt. F. W. Webb. 



The frames, barrel of boiler, and fire-box casing, are of steel, and the axles 

 and many of the working parts are also of steel. 



2212 j. Four Wheels coupled Passenger Engine, for 



heavy gradients. Size of cylinders, 17" X 24" stroke. Diameter 

 of coupled wheels, 5 ft. 6 in. Weight in working order, 

 31 tons, 8 cwt. F. W. Webb. 



The barrel of the boiler and fire-box casing are of steel, and the axles and 

 many of the working parts are also of steel. 



1942. Model of Agricultural Locomotive Engine, fitted 

 with patent side-plate brackets. Aveling and Porter. 



This represents one of Aveling and Porter's road locomotive engines. 

 The single cylinder is placed on the forward part of the boiler, and is sur- 

 rounded by a jacket in direct communication with it ; the steam is taken into 

 the cylinder from a dome connected with the jacket. Priming is by this 

 means prevented, the use of steam-pipes either inside or outside the boiler is 

 rendered needless, and a considerable economy in fuel is effected. The crank- 

 shaft brackets are formed out of the side plates of the fire-box extended up- 

 wards and backwards in one piece, so as not only to carry the erank-shaft 5 but 

 to provide bearings also for the counter-shaft and driving-axle, in the most 

 convenient position. This arrangement produces a combination of much 

 strength and lightness, reduces to a minimum the loss and annoyance from 

 leakage at strained bolt holes, and unites all parts, peculiarly exposed to 

 injury by jarring, with such firmness as to give almost absolute security 

 against such injury on even very rough roads. The driving wheels are of 

 wrought iron, and are fitted with compensating motion for turning sharp 

 curves without disconnecting either wheel ; they carry about 85 per cent, of 

 the weight of the engine. The engine is steered from the foot-plate. The 

 boiler is made of best quality plates, and tested with cold water to 200 : lbs. on 

 the square inch ; the fire-box is of Lowmoor iron. 



1947. Sectional Model of a Locomotive* 



Paul Lochmanri) Zeitz. 



