peasant, Jacques, is admirable, and gives us a satisfactory idea of the integrity and independence of the rural Frenchman. Dufour, the suspicious artist, is a delicious full-length. The true hero of the whole is, however, M. de Saint Elme, the fashionable swindler. The impudence, the ease, the volubility, the vivacity, the dexterity, of this chevalier d'industrie, are altogether marvellous. It is nearly impossible to give satisfactory extracts from this writer, or we should be tempted to exhibit some traits of this truly Parisian adventurer. But Paul de Koch spreads a character over the whole of his four volumes; scarcely a page occurs without a characteristic stroke of humour, and every successive trait fills in with the rest, and harmonizes the whole picture; whilst the extraction of any one would forcibly remind the reader of the brick and the house-vendor. There is nothing more remarkable in this writer than the thorough-going consistency of his characters: the conception is one and entire ; and every speech, word and action is as true to the genius of each personage as it is found to be in real life.

ART. VII.-1. Considérations sur les Chemins de Fer, et sur les Machines Locomotives, par M. J. Cordier. Paris, 1830. Svo. 2. Traité pratique sur les Chemins en Fer, et sur la Théorie des Chariots à Vapeur, &c., traduit de l'Anglais de M. Tredgold, par J. Duperré. Paris, 1881. 8vo.

THE substitution of the power of steam for the strength of horses in propelling carriages, coaches, and waggons, has now been the subject of general and sustained interest for more than twenty years; the expectations, even of the less sanguine, have been raised periodically, and after intervals of nearly equal duration, to the full assurance of perfect confidence, by the reported and apparently entire success of some fortunate projector in effecting the complete solution of the grand problem; expectations that have only deepened the total disappointment by which they have been invariably succeeded. There is not at this moment, in this country or in any other, a single instance of a regular land communication satisfactorily sustained by the agency of steam. On common roads we have never seen anything better than short-lived and unproductive experiments; on rail-roads (chemins de fer) they can scarcely be said to have been more successful. On the Liverpool and Manchester line they are only retained by an enormous sacrifice of money and of the interests of the proprietors. The steam-engines used on it are huge, disproportioned, clumsy masses of mechanism, better

adapted in their size and structure to the staid and sober pace of an elephant, than to the rapid flight for which they are used; and, though by being urged to the uttermost, they have attained velocities approximating nearer to aerial flight than earthly trudge, yet, like a cart horse goaded to a gallop, they founder themselves, and knock the road to pieces. From all that has yet been made public, we are only warranted to deduce this one conclusion,— that every attempt yet made to render steam-carriages the means of economical and regular inland communication has totally and absolutely failed.

Reduced to this condition, it may be well to inquire into our prospects. Is there, we may ask, any peculiarity in the nature of land locomotion, to prevent that power which turns the wheels of a boat, from propelling with similar effect, the wheels of a britchka? Is there anything in the nature of a carriage so peculiar, that, while a steam-engine can do the work of a hundred horses, it cannot do the work of "four-in-hand?" Have we attained the "hitherto and no further" of the power of steam? Knowing, as we do, that the proposed substitution would bring about a great and beneficial change in the moral, political, and commercial state of the empire, are we at last, after hopes so long and so fondly cherished, so long pregnant with apparent fruition, doomed to discover that we have only been tantalized? Are we to find that we have been hunting after nothing more attainable, than an alchymist's stone for converting steel and steam into oxen and corn, and baking the bread of the poor from the dust of the highway? Is all the mechanical skill of Great Britain at last foiled? Is all her science, all her ingenuity, unequal to the evolution of this little problem,-" with an engine of sixteen-horse power, to propel a four-horse coach?" Where is the present race of the Bells, the Boltons, and the Watts? Can the government do nothing to foster the invention and bring it to maturity? These questions are serious:-the answers to them weighty, all important to us--to Great Britain. We think they can be answered fully and satisfactorily, so as to show, that not in the nature of the thing to be doue, but in the mode of setting about it, is the cause of failure to be discovered. We may be able to detect in each invention omissions and elements of selfdestruction necessarily involving total failure, and these not in mere details, but in the great principles of structure and arrangement. By asking the question, What has been done? we may elicit the answer to its successor, What is to be done? For the more perfect understanding of the subject, we shall arrange our observations under the following heads:

1. The nature of steam,the manner in which it may be made

to produce the direct motion of a carriage-the various peculiarities that are requisite to form a good steam-carriage, and the difficulties in the way of their effective combination.

2. The causes of failure in such attempts as have been most nearly successful.

3. The ways and means of attaining success, and the advantages to be expected from it.

I. Of inventions, as of infants, some are occasionally observed shooting rapidly up to precocious maturity, and, like the infant Lyra, or the young Roscius, attaining an early perfection of power, which subsequent training and extended experience never enable them to surpass. Like Richard III. born with a full set of teeth, they come forth from the hand of creation in possession of amply developed capabilities. Such exactly has been the history of the steam-engine. Till the time of Watt, it scarcely existed in a form more important than a philosophical toy. He produced it at once-what he has left it to us-a perfect engine. Since his day we have done nothing, added nothing, improved nothing. We may have multiplied its duties, and assigned to its performance a variety of tasks; we may have effected a trivial saving in the amount of the fuel it consumes, or the quantity of space it may occupy; but no new feature have we added to the engine itself. We have made no improvement in its construction greater than we produce in the mechanism of a man, when we set him to a variety of trades and occupations. Steam was made a water-pumper, but has now become a miner and a mariner, a coal-heaver and a cotton-spinner, a cook and a coffee-mill, a universal agent and jack-of-all-trades.

By separating carefully in our minds the structure of the steamengine itself from the machinery of its applications, we shall very materially contribute to the clearness and accuracy of our notions on the subject. In regard to most of the latter, steam is only superior to water, or wind, or horse-power, in being more easily, or uniformly, or economically obtained. The means by which steam is made to produce uniform and continuous motion are nearly the same in all its varieties: at least there are only two great species of the engine that differ in any important point; the High Pressure, and the Low Pressure engines; the former consisting of two great members or parts, and the latter of three. The two parts of the first are the boiler for generating steamand the cylinder with its piston, and apparatus of cocks and passages admitting the steam above and below the piston, and allowing its escape into the air alternately. We take it for granted that our readers are sufficiently acquainted with these to

render any detailed description of them in this place unnecessary. In the Low Pressure Engine, instead of allowing the steam to pass off into the air, there is added a third part, a condenser, or cooling apparatus for condensing the steam and reconverting it into water, by which a considerable saving of heat, fuel and power is effected.

It is the High Pressure Engine alone which is used in steamcarriages: the great quantity of cold water, and the weight of the cooling apparatus, render the condensing engine too cumbrous for light and rapid motion. The proximity of cold water, and the buoyancy of a ship, make it much more suitable to the` of navigation.

purposes

The adaptation of steam to the purposes of propelling carriages is made in this way-a steam-engine and a boiler, with a supply of water, are set in the body of the carriage, or placed upon it above the hinder axle, so as to be in the vicinity of the great wheels of the vehicle; a rod is then attached at one extremity to a moving part of the engine, and the other end clasps a handle, either in the axis or upon a spoke of each wheel, so that, as the piston of the engine moves up and down, the wheels are forcibly turned round, and the engine with its carriage moves forwards.

These simple steps are all that are necessary to the construction of a steam-carriage. Having ascertained that the general use of a steam-engine is to turn the wheels of machinery, we place it on four wheels, and make the wheels which it turns identical with those which carry it, so that by turning them it carries itself forward; the passengers either sit in the same carriage with the engine, or are carried in a separate vehicle which it draws after it.

That an application so simple should have been suggested and executed at a very early period in the history of steam, appears not at all wonderful. The first suggestion is said to be due to Professor Robison of Edinburgh, the friend of Watt. The execution of the plan remained to Richard Trevithick of London, who, in 1802, perfectly solved the problem by producing a steamcarriage that ran on the common road, and was perfectly manageable, but, owing to the state of the roads at that time, the machinery was jolted so severely in a rapid motion as to be speedily rendered useless.

Even previous to this period, towards the end of the last century, experiments were still more successfully made in Pennsylvania by Oliver Evans, an American mechanic of considerable ingenuity. Having made, or rather invented, a particular modification of the steam-engine, he first used it to grind flour, then placed it in a carriage to drive the same flour to market, and,

having to cross a river on the way, he substituted paddle-wheels for those of the carriage, the body of which was formed as a boat, and having crossed the ferry, the load was safely marketted by the same engine. We have not learned why this conveyance was discontinued.

It appears therefore, that, so long as thirty years ago, steamcarriages were constructed both on a large and a small scale, by which the practicability of the application was perfectly proved, and its efficiency established, in so far as progressive motion by turning round the wheels was concerned; while on the other hand, the fact that they have never yet taken the road as regular conveyances, stares us in the face. Every man who is moderately familiar with the public prints of the last twenty years, must be well aware that labourers in the field of invention have been neither "few nor far between," but that each invention, as it has followed its predecessor in public favour, has succeeded it also, after no long interval, in total failure. Even now, we hear daily of successful experiments-of mountains ascended and descended at 10 and 50 miles an hour with enormous loads of 5 and 8 tons, and the power of 30 or 40 horses gained by pressures of millions of pounds.* We see them advertised as shortly to run-as about to be started on the common road, Yet the person who knows this must also know that there does not exist at this moment in Great Britain a single public road upon which a conveyance is carried on by steam at even the ordinary moderate velocities.

These constantly-repeated failures, and the large sums of money squandered in them, point with no ambiguous indication to the existence of radical errors or fatal oversights that cannot lie immediately on the surface of the subject, but must lurk deep in some recess not hitherto penetrated. A few simple considerations may perhaps lead us to form some idea of the obstacles to success, and the amount of the obstructions they may oppose.

1. The first of these may lie in the boiler Common boilers are generally made of thick iron plates, forming a strong chest or close box, about half full of water, the fire being placed under the bottom of the boiler, and the chimney around its sides; the quantity as well as the power of the steam depend on the largeness of the fire, and the extent of the surface of the boiler exposed to it. An engine for a carriage will require at least a surface of seven yards in length, and one yard in width, to be directly exposed to the fire; so that, supposing the boiler and

* A late speculator states that his carriage has 30 horse power, and yet we find that its greatest velocity on the level was 12 miles. Query, if 4 horses take a carriage 10 miles an hour, at what speed shall 30 horses take it?