EXPLANATION OF THE PLATES. 
407 
Duplicates of such of the parts as are liable to derangement are kept in readiness, 
powerful cranes and hoisting girders are fixed, and the various tools so arranged that 
the taking to pieces and refixing any part of the engine and pump can be effected 
without loss of time. 
The engine is calculated to raise 2250 gallons of water per minute. 
PLATES LXXXIX. to XCII. 
PATENT LOCOMOTIVE ENGINE, 
MADE BY MESSRS. R. STEPHENSON AND CO., NEWCASTLE-ON-TYNE, 
FOR THE LONDON AND BIRMINGHAM RAILWAY. 
This engine was made in 1836 for Messrs. Cubitt, the contractors for constructing 
a part of the London and Birmingham Railway near Berkhampstead, and was used 
by them for carrying the earth excavated in the construction of the line. The engine 
was employed in this manner for about a year and a half; when, the works being 
nearly completed, it was no longer required, and was purchased by the Railway 
Company for the purpose of carrying ballast for repairing the road, and other similar 
purposes, in which work it is now employed together with other engines. 
Although the original cost of these engines is very considerable, being about £1400 
each, it is found to be advantageous to use them in executing the earthwork of rail 
ways when the earth has to be carried to any considerable distance, as they take the 
place of so many horses and greatly expedite the work. They are also generally 
worth a great deal when done with for the particular purpose, as was the case with 
this engine, which was sold for upwards of two thirds of its original cost. The 
expense of using them is nearly the same as that of doing the same work by horses, 
if the saving of time from the greater speed and heavier loads that can be carried are 
not taken into the account; but the advantage in these respects is so great that 
locomotive engines are generally used for the works of railways whenever the earth 
work is of any considerable importance. 
A locomotive engine differs considerably from other steam engines in many 
particulars, as the engine and boiler are combined together in one machine, and have 
to be carried along at a great velocity, together with the fuel and water required 
for supplying the boiler. Very considerable modifications in the construction are 
thus rendered necessary, in order to obtain sufficient lightness and compactness 
combined with the requisite power. The cylinders are very much smaller than is 
usual in other engines, the steam used being of very high pressure ; the boiler is also 
made of small dimensions in proportion to the power, for the sake of portability,