The steam engine familiarly explained and illustrated; with an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain maxims for railway speculators. By the Rev. Dionysius Lardner ... With additions and notes by James Renwick ...

LOCOMOTIVE ENGINES ON TURNPIKE ROADS. 233
burst. I have stood close to a locomotive on the railroad
when the boiler burst. The effect was that the water passed
through the tubes into the fire and extinguished it, but no
other consequence ensued.
In fig. 65 is represented the appearance of a locomotive
of Mr. Gurney's, drawing after it a carriage for passengers.
Fig. 65.
(109.) One of the greatest difficulties which locomotives
upon a turnpike road have to encounter is the ascent of very
steep hills, for it is agreed upon all hands that hills of very
moderate inclinations present no difficulty which may not
be easily overcome, even in the present state of our knowledge. The fact of Mr. Gurney having propelled his carriage up Old Highgate Hill, when the apparatus was in a
much more imperfect state than that to which it has now
attained, establishes the mere question of the possibility of
overcoming the difficulty; but it remains still to be decided
whether the inconvenience caused by providing means of
meeting the exigency of very steep hills may not be greater
than the advantage of being able to surmount them can compensate for: and Mr. FJarey, whose authority upon subjects
of this kind is entitled to the highest respect, thinks that it
is upon the whole more advantageous to provide, at very steep
hills, post horses to assist the steam carriage up them, than to
incur the inconvenience of providing the necessary power and
strength of machinery for occasions which at best but rarely
occur. If the question merely referred to the command of mctive power, it appears to me that Mr. Gztrney's boiler would
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