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EXPLANATION OF THE PLATES. 
PLATE LXV. 
SECTION OF LOCOMOTIVE ENGINE, STANHOPE AND TYNE RAILWAY. 
Plate LXV. is a general section of the engine, divested of its internal apparatus of 
tubes, &c., in order to prevent unnecessary complication, and to explain more clearly 
the more important divisions of the engine. 
A locomotive engine is thus shewn to consist of three principal divisions ; namely, 
A, the external fire-box, containing the internal one in which the fuel is placed ; B, 
the boiler, of a cylindrical form, containing the brass tubes placed longitudinally from 
the smoke-box end D, to the fire-box end A ; through these tubes the flame cir 
culates, thereby distributing a maximum quantity of heated surface to the water. 
The boiler contains two or more long stays, E E, extending from the internal plate of 
the smoke-box end to the external plate of the fire-box end ; the use of these stays 
is for preventing too great a strain upon the tubes by the expansion of the metal. In 
the earlier engines considerable inconvenience was experienced by the cylinders be 
coming primed, in consequence of water and steam coming over together and entering 
them, occasioned principally by the motion of the engine. This inconvenience has 
been obviated by the introduction of the chamber or steam-head C, into which the 
steam rises ;—-from the interior of this chamber the steam is conducted by a pipe 
(not shewn) to the cylinders. The relative position of the cylinders, piston, and 
guide frame, to preserve the parallelism of the piston-rod is shewn, by the references 
F, G, and H ; I is the connecting rod attached to the crank J ; K the man-hole for 
ascertaining the state of the fire-box, and as an entrance for the purpose of cleaning 
the same. The fire-bars L, it will be seen, are so placed that with a short lever 
they may be unhooked from their position, and the whole of the fire allowed to fall 
out when no longer required. M is the fire or furnace door. 
PLATE LXVI. 
SAFETY VALVES, STANHOPE AND TYNE RAILWAY LOCOMOTIVE ENGINE. 
This Plate contains drawings to a working size of the two kinds of safety valves 
usually employed upon locomotive engines. Fig. 1 is a longitudinal section of the 
lever safety valve, with the application of Salter’s improved spring balance at 
tached instead of a weight. Fig. 2 is an elevation of the back of the balance, on