(100.) The effects of steam compared with horse-power, at lower rates of motion, will exhibit the advantages of the former, though in a less striking degree. An eight-horse wagon commonly weighs 8 tons, and travels at the rate of 2-1/2 miles an hour. Strong horses working in this way can travel 8 hours daily; thus each horse performs 20 miles a day. The performance, therefore, of each horse may be taken as equivalent to 20 tons transported 1 mile; and his performance on a railway being 20 times this amount, may be taken as equivalent to 400 tons transported 1 mile a day. The performance of a horse working in this manner is, therefore, 5 times the performance of a horse working at 10 miles an hour; the latter effecting only the performance of 4 tons transported 1 mile per day on a good turnpike road, or 80 tons on a railway. We shall hence obtain the proportion of the performance of horses working in wagons to that of a locomotive steam engine. Since 2 lbs. of coke are equivalent to the daily performance of a horse in a mail-coach, and 40 lbs. on a railway, at 10 miles an hour, it follows that 10 lbs. will be equivalent to the performance of a horse on a turnpike road, and 200 lbs. on a railway, at 2-1/2 miles an hour. Since a locomotive engine can perform the daily work of 7500 mail-coach horses, it follows that it performs the work of 1500 wagon horses.
These results must be understood to be subject to modifications in particular cases, and to be only average calculations. Different steam-engines, as well as different horses, varying in their performance to a considerable extent; and the roads on which horses work being in different states of perfection, and subject to different declivities, the performance must vary accordingly.
In the practical comparison, also, of the results of so powerful an agent as steam applied on railways, with so slight a power as that of horses on common roads, it must be considered that the great subdivision of load, and frequent times of starting, operate in favour of the performance of horses; inasmuch as it would oftener occur that engines capable of transporting enormous weights would start with loads inferior to their power, than would happen in the application of horse-power, where small loads may start at short intervals. This, in fact, constitutes a practical difficulty in the application of steam engines on railroads; and will, perhaps, for the present, limit their application to lines connecting places of great intercourse.
The most striking effect of steam power, applied on a railroad, is the extreme speed of transport which is attained by it; and it is the more remarkable, as this advantage never was foreseen before experience proved it. When the Liverpool and Manchester line was projected, the transport of heavy goods was the object chiefly contemplated; and although an intercourse in passengers was expected, it was not foreseen that this would be the greatest source of revenue to the proprietors. The calculations of future projectors will, therefore, be materially altered, and a great intercourse in passengers will be regarded as a necessary condition for the prosperity of such an undertaking.
If this advantage of speed be taken into account, horse-power can scarcely admit of any comparison whatever with steam-power on a railway. In the experiments which I have already detailed, it appears that a steam engine is capable of drawing 90 tons at the rate of about 20 miles an hour, and that it could transport that weight twice between Liverpool and Manchester in about 3 hours. Two hundred and seventy horses working in wagons would be necessary to transport the same load the same distance in a day. It may be objected, that this was an experiment performed under favourable circumstances, and that assistance was obtained at the difficult point of the inclined plane. In the ordinary performance, however, of the engines drawing merchandise, where great speed is not attempted, the rate of motion is not less than 15 miles an hour. In the trains which draw passengers, the chief difficulty of maintaining a great speed arises from the stoppages on the road to take up and let down passengers. There are two classes of carriages at present used: the first class stops but once, at a point half-way between Liverpool and Manchester, for the space of a few minutes. This class performs the thirty miles in an hour and a half, and sometimes in 1 hour and 10 minutes. On the level part of the road its common rate of motion is 27 miles an hour; and I have occasionally marked its rate, and found it above 30 miles an hour.
But these, which are velocities obtained in the regular working of the engines for the transport of passengers and goods, are considerably inferior to the power of the present locomotives with respect to speed. I have made some experimental trips, in which more limited loads were placed upon the engines, by which I have ascertained that very considerably increased rates of motion are quite practicable. In one experiment I placed a carriage containing 36 persons upon an engine, with which I succeeded in obtaining the velocity of about 48 miles an hour, and I believe that an engine loaded only with its own tender has moved over 15 miles in 15 minutes.
It will then perhaps be asked, if the engines possess these great capabilities of speed, why they have not been brought into practical operation on the railroad, where, on the other hand, the average speed when actually in motion, does not exceed 25 miles an hour? In answer to this it may be stated, that the distance of 30 miles between Liverpool and Manchester is performed in an hour and a half, and that 10 trains of passengers pass daily between these places: the mail, also, is transmitted three times a day between them. It is obvious that any greater speed than this, in so short a distance, would be quite needless. When, however, more extended lines of road shall be completed, the circumstances will be otherwise, and the despatch of mails especially will demand attention. Full trains of passengers, commonly transported upon the Manchester railroad, weigh about 50 tons gross: with a lighter load, a lighter and more expeditious engine might be used. The expense of transport with such an engine would of course be increased; but for this the increased expedition there would be ample compensation. When, therefore, London shall have been connected with Liverpool, by a line of railroad through Birmingham, the commercial interest of these places will naturally direct attention to the greatest possible expedition of intercommunication. For the transmission of mails, doubtless, peculiar engines will be built, adapted to lighter loads and greater speed. With such engines, the mails, with a limited number of passengers, will be despatched; and, apart from any possible improvement which the engines may hereafter receive, and looking only at their present capabilities, I cannot hesitate to express my conviction that such a load may be transported at the rate of above 60 miles an hour. If we may indulge in expectations of what the probable improvements of locomotive steam engines may effect, I do not think that even double that speed is beyond the limits of mechanical probability. On the completion of the line of road from the metropolis to Liverpool we may, therefore, expect to witness the transport of mails and passengers in the short space of three hours. There will probably be about three posts a day between these and intermediate places.
The great extension which the application of steam to the purpose of inland transport is about to receive from the numerous railroads which are already in progress, and from a still greater number of others which are hourly projected, impart to these subjects of inquiry considerable interest. Neither the wisdom of the philosopher, nor the skill of the statistician, nor the foresight of the statesman is sufficient to determine the important consequences by which the realization of these schemes must affect the progress of the human race. How much the spread of civilization, the diffusion of knowledge, the cultivation of taste, and the refinement of habits and manners depend upon the easy and rapid inter-mixture of the constituent elements of society, it is needless to point out. Whilst population exists in detached and independent masses, incapable of transfusion amongst each other, their dormant affinities are never called into action, and the most precious qualities of each are never imparted to the other. Like solids in physics, they are slow to form combinations; but when the quality of fluidity has been imparted to them, when their constituent atoms are loosened by fusion, and the particles of each flow freely through and among those of the other, then the affinities are awakened, new combinations are formed, a mutual interchange of qualities takes place, and compounds of value far exceeding those of the original elements are produced. Extreme facility of intercourse is the fluidity and fusion of the social masses, from whence such an activity of the affinities results, and from whence such an inestimable interchange of precious qualities must follow. We have, accordingly, observed, that the advancement in civilization and the promotion of intercourse between distant masses of people have ever gone on with contemporaneous progress, each appearing occasionally to be the cause or the consequence of the other. Hence it is that the urban population is ever in advance of the rural in its intellectual character. But, without sacrificing the peculiar advantages of either, the benefits of intercourse may be extended to both, by the extraordinary facilities which must be the consequence of the locomotive projects now in progress. By the great line of railroad which is in progress from London to Birmingham, the time and expense of passing between these places will probably be halved, and the quantity of intercourse at least quadrupled, if we consider only the direct transit between the terminal points of the line; but if the innumerable tributary streams which will flow from every adjacent point be considered, we have no analogies on which to build a calculation of the enormous increase of intercommunication which must ensue.
Perishable vegetable productions necessary for the wants of towns must at present be raised in their immediate suburbs; these, however, where they can be transported with a perfectly smooth motion at the rate of twenty miles an hour, will be supplied by the agricultural labourer of more distant points. The population engaged in towns, no longer limited to their narrow streets, and piled story over story in confined habitations, will be free to reside at distances which would now place them far beyond reach of their daily occupations. The salubrity of cities and towns will thus be increased by spreading the population over a larger extent of surface, without incurring the inconvenience of distance. Thus the advantages of the country will be conferred upon the town, and the refinement and civilization of the town will spread their benefits among the rural population.[32]
(101.) The quantity of canal property in these countries gives considerable interest to every inquiry which has for its object the relative advantage of this mode of transport, compared with that of railways, whether worked by horses or by steam-power; and this interest has been greatly increased by the recent extension of railway projects. This is a subject which I shall have occasion, in another work, to examine in all its details; and, therefore, in this place I shall advert to it but very briefly.