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profession; but he was an extensive coal proprietor. Coal had before his time been uniformly carried from the Tyne to London by sea, and was familiarly called sea-coal. Stephenson, mainly on his own account, established the inland coal trade by rail to the metropolis. His health, comparatively enfeebled by an attack of pleurisy, could not resist the noxious atmosphere of his green-houses, where he spent much time in superintending the culture of his exotics. To this cause was attributed the attack of intermittent fever, which carried him off on the 12th of August, 1848, in the sixty-seventh year of his age. He was buried in Trinity Church, Chesterfield. Ralph Waldo Emerson, who met him when in England in 1847, observed that he had the lives of many men in him.

George Stephenson was a man of iron frame of body and mind, of plain manners, ardent temperament, eminently social habits; too confident of his powers and too sure of his position to be ambitious. Sir Robert Peel made him the offer of knighthood more than once; but Stephenson preferred his sturdy independence to the precarious privileges of the titled class. He unflinchingly pursued his own ends, and seldom failed in accomplishing his objects.

THE FIRST LOCOMOTIVE.

When the project of connecting Liverpool and Manchester by a double line of railway was undertaken, it was not decided what moving power it might be most expedient to adopt as a means of transport on the proposed road: the choice lay between horse power, fixed steam engines, and locomotive engines; but the first, for many obvious reasons, was at once rejected in favor of one or other of the last two.

The steam engine may be applied, by two distinct methods, to move wagons either on a turnpike road or on a railway. By the one method the steam engine is fixed, and draws the train of carriages toward it by a chain extending the whole length of the road on which the engine works. By this method the line of road over which the transport is conducted is divided into a number of short intervals, at the extremity of each of which an engine is placed. The wagons or carriages, when drawn by an engine to its own station, are

detached, and connected with the extremity of the chain worked by the next stationary engine; and thus the journey is performed, from station to station, by separate engines. By the other method, the same engine draws the load the whole journey, traveling with it.

The Directors of the Liverpool and Manchester Railroad, when the work was advanced towards its completion, employed in the spring of the year 1829 Messrs. Stephenson and Lock and Messrs. Walker and Rastrick, experienced engineers, to visit the different railways where practical information respecting the comparative effects of stationary and locomotive engines was likely to be obtained; and from these gentlemen they received reports on the relative merits, according to their judgment, of the two methods. The result of the comparison of the two systems was, that the capital necessary to be advanced to establish a line of stationary engines was double that which was necessary to establish an equivalent power in locomotive engines; that the annual expense by the stationary engines was likewise greater; and that, consequently, the expense of transport by the latter was greater, in a like proportion.

On the score of economy, therefore, the system of locomotive engines was entitled to a preference; but there were other considerations which conspired with this to decide the choice of the Directors in its favor. An accident occurring in any part of a road worked by stationary engines must necessarily produce a total suspension of work along the entire line. The most vigilant and active attention on the part of every workman, however employed, in every part of the line, would therefore be necessary; but, independently of this, accidents arising from the fracture or derangement of any of the chains, or from the suspension of the working of any of the fixed engines, would be equally injurious, and would effectually stop the intercourse along the line. On the other hand, in locomotive engines an accident could only affect the particular train of carriages drawn by the engine to which the accident might occur; and even then the difficulty could be remedied by having a supply of spare engines at convenient stations along the line.

The decision of the Directors was, therefore, in favor of locomotive engines; and their next measure was to devise some means by which the inventive genius of the country might be stimulated to supply them with the best possible form of engines for this purpose. With this view it was proposed and carried into effect to offer a prize for the best locomotive engine, which might be produced under certain proposed conditions, and to appoint a time for a public trial of the claims of the candidates. A premium of £500 was accordingly offered for the best locomotive engine to run on the Liverpool and Manchester Railway; under the condition that it should produce no smoke; that the pressure of the steam should be limited to 50 lbs. on the inch; and that it should draw at least three times its own weight, at the rate of not less than ten miles an hour; that the engine should be supported on springs, and should not exceed fifteen feet in height. Precautions were also proposed against the consequences of the boiler bursting. This proposal was announced in the spring of 1829, and the time of trial was appointed in the following October.

The engines which finally underwent the public trial were the Rocket, constructed by Mr. Stephenson; the Sanspareil, by Hackworth; and the Novelty, by Messrs. Braithwait and Ericson. A line of railway was selected for the trial, on a level piece of road about two miles in length, near a place called Rainhill, between Liverpool and Manchester; the distance between the two stations was a mile and a half, and the engine had to travel this distance backward and forward ten times, which made altogether a journey of 30 miles. The Rocket performed this journey twice: the first time in 2 hours 14 minutes and 8 seconds; and the second time in 2 hours 6 minutes and 49 seconds. Its speed at different parts of the journey varied: its greatest rate of motion was rather above 29 miles an hour; and its least, about 111⁄2 miles an hour. The average rate of the one journey was 13.4 miles an hour; and of the other, 14.1 miles. This was the only engine which performed the complete journey proposed, the others having been stopped from accidents which occurred to them in the experiment. The Sanspareil performed the distance

between the stations eight times, traveling 221⁄2 miles in I hour, 37 minutes and 16 seconds. The greatest velocity to which this engine attained was something less than 23 miles per hour. The Novelty had only passed twice between the stations when the joints of the boiler gave way, and put an end to the experiment. The Rocket obtained the premium.

The great object to be attained in the construction of these engines was, to combine with sufficient lightness the greatest possible heating power. The fire necessarily acts on the water in two ways: first, by its radiant heat; and second, by the current of heated air which is carried by the draft through the fire, and finally passes into the chimney. To accomplish this object, therefore, it is necessary to expose to both these sources of heat the greatest possible quantity of surface in contact with the water. These ends were attained by the following arrangement in the Rocket. The engine is supported on four wheels; the principal part of the weight being thrown on one pair, which are worked by the engine. The boiler consists of a cylinder six feet in length, with flat ends; the chimney issues from one end, and to the other end is attached a square box, the bottom of which is furnished with the grate on which the fuel is placed. This box is composed of two casings of iron, one contained within the other, having between them a space about 3 inches in breadth; the magnitude of the box being 3 feet in length, 2 feet in width, and 3 feet in depth. The casing which surrounds the box communicates with the lower part of the boiler by a pipe; and the same casing at the top of the box communicates with the upper part of the boiler by another pipe. When water is admitted into the boiler, therefore, it flows freely through the pipe into the casing which surrounds the furnace or fire-box, and fills this casing to the same level as that which it has in the boiler. When the engine is at work, the boiler is kept about half filled with water; and, consequently, the casing surrounding the furnace is completely filled. The steam

which is generated in the water contained in the casing finds its exit through a pipe, and escapes into the upper part of the boiler. Through the lower part of the boiler pass a number of copper tubes of small size, which communicate at one end

with the fire-box, and at the other with the chimney, and form a passage for the heated air from the furnace to the chimney. The ignited fuel spread on the grate at the bottom of the fire-box disperses its heat by radiation, and acts in this manner on the whole surface of the casing surrounding the fire-box; and thus raises the temperature of the thin shell of water contained in that casing. The chief part of the water in the casing, being lower in its position than the water in the boiler, acquires a tendency to ascend when heated, and passes into the boiler; so that a constant circulation of the heated water is maintained, and the water in the boiler must necessarily be kept at nearly the same temperature as the water in the casing. There are two cylinders, one of which works each wheel. The spokes which these cylinders work are placed at right angles on the wheels; the wheels being fixed on a common axle, with which they turn.

In this engine, the surface of water surrounding the fire box, exposed to the action of radiant heat, amounted to 20 square feet, which received heat from the surface of 6 square feet of burning fuel on the bars. The surface exposed to the action of the heated air amounted to 118 square feet. The engine drew after it another carriage, containing fuel and water; the fuel used was coke, for the purpose of avoiding the production of smoke.-D. LARDNER.

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