[Lectures on the Steam-Engine, by the Rev. Dionysius Lardner, LL. D.
4th Edit. 12mo. London, 1832. Taylor. Price 7_s._ 6_d._]
This is decidedly the best popular account which we have of the
Steam-Engine,--the most accurate and complete and at the same time the
most intelligible and interesting. The book is intended for the use of
unscientific readers, or of the public generally; but it has the unusual
advantage, for a work of this description, of being written by a person
of the highest scientific acquirements. The utmost dependence,
therefore, may be placed on the correctness of the various descriptions
and explanations it presents; they are stripped indeed of those
technicalities which would have rendered them both repulsive and obscure
to ordinary readers,--but the substance of the statement which remains,
although thus transformed from a full and precise detail to a general
outline, is still, in so far as it goes, perfectly clear and
satisfactory. The volume contains all that most persons, with the
exception of engineers and mathematicians, can be supposed desirous of
knowing about the exceedingly curious and important subject of which it
treats. It both describes the steam-engine as it now exists, and it
relates its origin and past history. After a preliminary lecture on the
natural forces on which the action of the contrivance depends, the
author proceeds to recount and describe the successive inventions and
improvements of the Marquis of Worcester--of Captain Savery--of Newcomen
and Cawdley--of Humphrey Potter (the boy who first hit upon the plan of
making the engine work its own valves),--and finally of the illustrious
Watt. The various parts of Watt’s single and double-acting engines are
explained with the fulness which their importance deserves in the fifth
and the three following lectures, the modifications which since his time
have been introduced in the valves, the boiler, the furnace, &c., being
also noticed. The ninth lecture is occupied with an account of the
double-cylinder engines of Hornblower and Woolf, and also of a very
ingenious and elegant machine, possessing certain peculiar and valuable
recommendations, suggested by the late Reverend Mr. Cartwright, the
well-known inventor of the power-loom. These expositions are in general
distinguished by very remarkable clearness--and, illustrated as they are
by abundance of excellent woodcuts and copper-plates, they can hardly
fail to be perfectly and easily understood even by those who have been
but little accustomed to such investigations.
The part of the book, however, on account of which we principally notice
it at present, is the new matter which appears for the first time in
this edition, and which relates to the two latest among the various
extraordinary applications of the power of steam;--the wonders that have
been performed by it on the Liverpool and Manchester railway, and the
still more recent experimental achievements of the several projectors
who have for some time past been endeavouring to introduce steam-coaches
upon our common roads. The two long chapters which are devoted to these
subjects, the first especially, contain a number of facts which had not
previously been laid before the public, and some of which are of
considerable interest.
The locomotive (or travelling) engines which are employed on the
Liverpool railway are all what are called high-pressure engines. One of
Watt’s most ingenious contrivances was his condensing apparatus, by
which, previous to every stroke of the piston, he created a vacuum in
the part of the cylinder through which it had to be driven, and thereby
enabled it to be sent forward through that space with a much inferior
pressure of steam to what would otherwise have been required. But in the
steam-engines affixed to coaches it is found convenient to dispense with
this apparatus, on account of its complexity, its weight, the room which
it would occupy, and above all the constant supply of cold water which
would be requisite to keep it in action. The consequence is that in
these engines and others similarly constructed, a much greater force of
steam is necessary to make the piston do its work; and they are on that
account denominated high-pressure engines. It is only within the last
thirty years that they have been introduced, and the most remarkable
proofs of their power have been afforded on the Liverpool railway, which
was opened only about two years ago.
Some time before it was opened a contest took place on this railway
between three different steam-coaches. The Rocket, constructed by Mr.
Stevenson; the Sans-pareil, by Mr. Hackworth; and the Novelty, by
Messrs. Braithwait and Ericson, for a prize of £500, offered by the
Directors to that which should accomplish the greatest distance in the
shortest time. On this occasion the Rocket, which gained the prize, went
over the space of 30 miles in 2 hours 6 minutes and 49 seconds, being at
the average rate of 14⅕ miles per hour. But in the course of the journey
it sometimes proceeded at the rate of above 29 miles an hour, and its
slowest motion was about 11½ miles in that time[1]. In May last, Dr.
Lardner saw the engine called the Victory draw on the same rail-road the
weight of 92 tons 19 cwt. 1 quarter, in twenty waggons, together with
its tender containing fuel and water, from Liverpool to Manchester, a
distance of 30 miles, in 1 hour 34 minutes and 45 seconds, besides 10
minutes spent in taking in water. The speed on this occasion was in some
places 25½ miles an hour, and on level ground, where there was no wind,
it was generally 20 miles an hour. On another day, the engine called the
Samson drew fifty waggons laden with merchandise, and, with itself,
making a gross weight of above 233 tons, the same distance in 2 hours
and 40 minutes, exclusive of delays upon the road for watering, &c., the
rate of motion having varied from 9 to 16 miles an hour, and being on an
average nearly 12 miles an hour. The coke consumed in this journey was
1762 lbs., or a quarter of a pound per ton per mile. The attendance
required is only an engine-man and a fire-boy, the former of whom is
paid 1_s._ 6_d._ for each trip, and the later 1_s_. The expense of the
original construction of the engines, however, and of their wear and
tear is very great, though not nearly so great on the latter account,
Dr. Lardner assures us, as has been sometimes stated. The price of one
of the most improved engines at first is about £800, and it will travel
from 25,000 to 30,000 miles without costing as much more for repairs.
Notwithstanding many extra expenses which this undertaking, as the first
of the kind, has had to bear, and from the experience purchased by which
future speculators will profit, it has been perfectly successful in a
commercial point of view. The profits on the capital invested have been
from the first above 6 per cent. per annum; and during the latter six
months of 1831, it was at the rate of above 8 per cent. per annum; and
it has since probably exceeded that amount. The original £100 shares
already sell for above £200. On the other hand the advantages to the
public have been as great as to the proprietors. Fully 600,000
passengers now pass by the rail-road in the course of the year between
Liverpool and Manchester, or four times as many as used formerly to make
the journey. The transference of merchandise is also effected both with
infinitely greater speed, and at a vast reduction of expense.
Some time ago a work was published by Mr. Gordon, the engineer, on the
application of steam as a moving power for coaches on common turnpike
roads, the facts contained in which were principally derived from the
report on this subject of the Committee of the House of Commons, which
was ordered to be printed on the 12th of October last. Dr. Lardner has
here availed himself of the information supplied by the same most
interesting and important parliamentary paper; some of the curious
details given in which we may possibly take another opportunity of
laying before our readers. In the meanwhile we can only afford room for
the general conclusions to which the Committee came on the evidence
brought before them. They are as follows:--
“1. That carriages can be propelled by steam on common roads at an
average rate of ten miles per hour.
“2. That at this rate they have conveyed upwards of fourteen passengers.
“3. That their weight, including engine, fuel, water, and attendants,
may be under three tons.
“4. That they can ascend and descend hills of considerable inclination
with facility and safety.
“5. That they are perfectly safe for passengers.
“6. That they are not (or need not be, if properly constructed)
nuisances to the public.
“7. That they will become a speedier and cheaper mode of conveyance than
carriages drawn by horses.
“8. That, as they admit of greater breadth of tire than other carriages,
and as the roads are not acted on so injuriously as by the feet of
horses in common draught, such carriages will cause less wear of roads
than coaches drawn by horses.
“9. That rates of toll have been imposed on steam-carriages, which would
prohibit their being used on several lines of road, were such charges
permitted to remain unaltered.”
The toll-bills complained of have since been repealed. “At the moment
that I write,” says Dr. Lardner, “several steam-carriages are in process
of construction for regular work upon the public roads of England. Some
are about to be established between Paddington and the Bank, upon the
New Road; others between London and Greenwich, and other places in the
vicinity of the metropolis. Another it is stated, is to run between
London and Birmingham. The first impulse once received, the progress
will be rapid, and the effect of proportionate importance.”
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Footnote 1:
In another place Dr. Lardner states that “the engine which conveyed
Mr. Huskisson to Manchester, after the unhappy occurrence which took
place at the great trial, moved at the rate of 35 miles an hour.” (p.
206.)
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