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anangement is peculiarly adapted to steam navigation, and of its use, the oscillating engines of Messrs. Penn, in the Exhibition, furnished highly-interesting examples.

From the exhibition of these two models, it appears very clearly that to the inventor of the steam-engine, James Watt, we are also indebted for the first ideas of locomotion by steam; and that the adjuncts of rails and paddles, and afterwards of screw-propellers, were added by other ingenious men who arose to put these ideas into practice. The idea obtained by Mr. Trevethick was carried into practice by himself and a Mr. Vivian, of Camborne near Redruth, in Cornwall, who jointly, in 1804, constructed and took out a patent for the first really useful locomotive.

in locomotive engines, may be judged from the representation, in fig. 214, of the leviathan "Lord of the Isles," exhibited in the Great Exhibition. This is a specimen of one of the ordinary class of engines constructed by the Great Western Company at their works at Swindon. The figure shows both the engine and the tender. It is capable of taking a passengertrain of 120 tons at an average speed of sixty miles an hour upon easy gradients. The evaporation of the boiler when in full work is equal to 1000-horse power; the effective power, as measured by a dynamometer, being equal to 743-horse power. The weight of the engine in working order is 35 tons, which does not include the tender, which, under similar circumstances, weighs 17 tons 13 cwts. The diameter of cylinder, 18 inches; the length of stroke, 24 inches; the diameter of the driving wheel, 8 feet; and the maximum pressure of steam, 120 lbs. The consumption of fuel with an average load of 90 tons, and an average speed of 29 miles an hour, including stoppages, as an ordinary mail train, averaged 20.8 lbs. of coke per mile. The stately proportions of this engine were seen to great advantage in the Crystal Palace; and, contrasted with the light locomotives of Messrs. Adams and England, seemed quite a giant of power and capability. To see this engine, however, in its full glory, the spectator should be at its side when it stops, after a heavy run at express speed; when its furnace is too white with heat for the naked eye to look upon without pain, and the steam, blowing off like thunder, shakes the very ground. One of these engines was nick-named by one of the men the "Emperor of Russia," on account of its extraordinary appetite for oil and tallow ! In order to distribute the weight more equally over the rails, the engine alone has eight wheels. The cylinders were laid horizontally under the front end of the boiler, and could be very conveniently inspected, together with the rest of the Fig. 213.

Fig. 213, is a representation of the side and end view of Messrs. Trevethick and Vivian's first locomotive. It consisted of a cylindrical boiler containing a tube of the U shape, one end of which formed the furnace, whilst to the other was connected the chimney. The power of the steam is conveyed to the wheels through the medium of the piston. This is made of metal, and slides in a cylinder, like the bucket of a pump in the barrel; and the steam being first let on to one side of it, forces it in one direction, and then on the other side, to force it in the other direction, thus keeps up the motion. The piston has a rod in the centre, passing through the cover at one end of the cylinder, to the end of which is attached a connecting rod, which takes hold of a pin in one of the spokes of the wheel, and turns it just as a man's arm turns a coffee mill. The engraving shows this primitive arrangement; and the cylinder a is partially sunk into the boiler, and the power is transmitted through the rods bb to the wheels cc.

An extraordinary misconception for a long period obstructed the use of locomotives. It was gravely alleged that the wheels would turn round without the engine advancing; and this

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working parts, by going down into the pit provided for that purpose under the engine.

notion having once got abroad, people would hardly be persuaded to the contrary, even when they saw it with their own eyes. Much money and great ingenuity were expended in making steam-walking machines, in which iron legs and feet were employed to push the engine along. George Stephenson, in 1814, constructed a locomotive for the Killingworth Col-engine would carry railway managers too far, and that when liery, when all these crude ideas were swept away, and from that time we may date the introduction of the locomotive system. When the Liverpool and Manchester Railway was projected in 1823, Mr. Stephenson and others spent large sums of money in improving the details of the engine; so that on the opening of that railway a very excellent performance was at once attained, and the benefits of the railway system began to be appreciated. The great superiority of the engines used on this line over that just described arose from the use of a boiler containing a number of tubes or small flues, through which the flame passed, and which generated steam much more rapidly than the former boiler with a single large tube through it. Since that date, the increase of power that has taken place

This system, as may be imagined, is best suited for main lines, where the traffic is very heavy. It had, however, been foreseen by some of our engineers that the rage for the heavy their eyes became open to the fact that more than half its power was exerted in moving itself merely, and knocking the rails and sleepers to pieces, they were as anxious to get back their light engines as they had formerly been to discard them. This led to the introduction of the light "locomotive carriage" of Mr. Adams, and the light engine of Mr. England. The specimens which they exhibited, whilst possessing all the advantages which experience and skill have worked out in the heavy engines, are not more than one-third of the weight and half the cost. Mr. Adams' plan consists in combining the engine and carriage in one, so that there is no superfluous weight. The boiler is a cylinder full of tubes placed vertically; but this plan, in subsequent engines, has been given up

Fig. 214.

in favour of the ordinary horizontal construction, as shown in the locomotive carriage in the Exhibition.

Mr. England, on the other hand, combines the engine and tender in one frame, thus adapting it to carriages of the ordinary description. Both these plans have been satisfactorily tested in practice, and bear out the views of the projectors, the engines carrying a moderate load at a high speed, with a small consumption of fuel, and less injury to the permanent way. In addition to these, specimens from numerous other eminent engineers were exhibited. Mr. Trevethick, of the London and North-Western Company, sent the express engine, the Cornwall," in which the boiler is placed very low, and the driving wheels are obtained of large size, by allowing the shaft on which they are fixed to pass through the boiler. Mr. Crampton, the patent narrow-gauge engine "Liverpool," said to be the most powerful engine in the world, being equal to 1140 horse power. The peculiarity of this engine consists in the position of the axle of the driving wheels, which is placed behind the fire-box. Mr. Fairbairn, of Manchester; Messrs. Wilson, of Leeds; and Messrs. Kitson, Thompson, and Hewitson, of the same town, exhibited specimens of the combined engine and tender variety, or "tank engines," as they are technically termed. There was also a very beautiful specimen of the first-class engine by Messrs. Hawthorn and Co., of Newcastle. The British visitor might consider, in dwelling on this collection of fire-steeds, that in this respect at least his country had no competitor. A traveller tells us, with pardonable exultation, how comforted and how much at home he felt at an Italian railway station, by seeing on the name-plate of the engine the familiar words, "Sharp, Roberts, and Co., Atlas Works, Manchester,' ," and hearing a genuine English "All right!" given, before the train was allowed to move from the platform.

One of the greatest improvements in the application of the steam-engine, which was fully displayed in the Great Exhibition, is its employment in agriculture. Among others, Messrs. Ransome and May, of Ipswich, exhibited a portable steam-engine (fig. 215), adapted for thrashing and other agricultural purposes, which is of very simple construction, and, having but few working parts, there is little liability of its getting out of order; the cylinder and the machinery are placed on the top of the boiler, and are therefore constantly under the eye of the engine-man, and very easy of access. The engine is fitted up with a superior governor, and an effective

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regulator-valve for stopping and controlling the speed of the engine. There is a simple and efficient feed-pump, which ensures at all times a regular supply of water to the boiler. The crank-shaft and connecting-rod are of wrought-iron, and the slide-valve

is of brass, and of the most approved construction. The steam and escape-pipes are of copper, and consequently not liable to injure the slide-valve and metallic packing of the piston, by any scales, caused by corrosion of the metal, coming off the pipes, and being carried by the steam into the working parts of the engine, as is frequently the case in common engines fi ted with wrought-iron gas-tubes (instead of copper) for steam-pipes. The boiler is of a superior description, and is made on the same principle as the best locomotive boilers, and will work with safety up to a pressure of 80 lbs. per square inch, if required. This engine requires little fuel, and is free from danger by fire to the surrounding ricks and farm-buildings, the box being enclosed in a wrought-iron ash-pan, which contains water, and effectually extinguishes all hot cinders as they fall from the fire-grate. The engine is supported on a strong neat framing, which is carried on springs, interposed between it and the axles of the wheels. This arrangement effectually preserves the machinery from the injurious shocks caused by

and making the eccentric to contain the same area in its cross section as the piston, and by confining it in its extremes, or, in other words, by causing "an eccentric to revolve in its own diameter," is the same in principle as the arrangement employed in the ordinary engine.

It will be seen that A represents a steam chamber or "cylinder," and в the eccentric or "piston," which is keyed fast on the shaft c. The back plate, D, is fitted into the recess, and is pressed against the piston, either by means of springs, or by the admission of steam behind it by the small steam-pipe, and is introduced for the purpose of compensating for any wear that takes place in the periphery of the piston. It also performs another important office: in cases of priming, it is forced back, and the water rushes from one side to the other of the piston until it escapes. The plate E is dovetailed in and fitted fast, so that all wearing parts can be renewed with the greatest facility, compared with boring of cylinders, etc., in the ordinary engine. The piston is made steam-tight at both ends, with rings of metal, KK, fitted into conical seatings,

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the roughness of the roads over which they frequently travel. These engines thrash, with ease, forty quarters of wheat of average yield per day, and are readily managed by an intelligent farm-servant, on whose care will depend, in a great measure, the quantity of fuel consumed.

Messrs. Simpson and Shipton's Patent Short-stroke Reciprocating Steam-Engine, shown in the Exhibition, though a close approximation to the ordinary engine in principle, differs materially in its mechanical construction. The peculiar properties of it are the direct conversion of rectilinear motion into circular, or the amalgamation of the piston and crank motion in one body. Fig. 216, No. 1, is a side elevation, and Fig. 216, No. 2, an end elevation of this engine. The eccentric, being a mechanical equivalent for a crank, if they be of the same "throw," and each attached to pistons of a certain area, they are equal in effect; by dispensing with the piston,

which are cut open on one side, leaving a lap joint. The shaft c is carried on the vibrating rods FF, and vibrates the distance of the eccentricity of the piston-slots of suitable form being provided in the side plates, LL, to allow the shaft to traverse clear. GG are cranks, and H H are connecting-rods which convey the power from the piston to the lower cranks, through direct lines, and are always parallel. The steam is admitted into the cylinder precisely as in the ordinary engine, viz. top and bottom of the piston alternately; although the valve used in this instance is rather different, as it exhausts through the back, and is packed in a similar manner to the piston's ends, being worked by an eccentric, weight, shaft, levers, etc., as in an ordinary arrangement.

The advantages claimed for this invention are as follows:The piston, receiving a reciprocating action from the steam, by reason of its mechanical arrangement, gives out a revolving mo

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loaded engines; but by the arrangements submitted, the crank shaft, which is the piston shaft, receives this shock, which is somewhat diminished on account of the piston itself gliding gradually out of equilibrium into full effect (the same as the common crank, though divested of the intermediate parts). An advantage is also obtained by working a short stroke with a large effective area of piston, and, consequently, a great speed, with slow velocity of the piston through space, is obtained, compared with the ordinary engine-thus the first motion can be

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pressure pendulous engine." Fig. 217, No. 1, and fig. 217, No. 2, represent a side and front elevation, respectively, of the engine. The cylinder is suspended by trunnions from the top, and the piston gives motion to a crank, on the shafts of which are the fly-wheel and pulley. By a band from the latter, motion is distributed to various pulleys and shafts, by which a variety of different machines are set and kept in motion. The engine is of simple construction, and does its work well. The principle, discovered by Woolf, of introducing steam of a high pressure into a small cylinder, and afterwards allowing it to act expansively in a larger one, adding to its effective force by condensation, is in this engine applied in an extremely ingenious and simple manner. The cylinders are not placed before each other, as is generally done in the beam-engine, but firmly bedded and jointed side by side, forming what might be termed a double cylinder, which cylinders the inventors, upon a principle entirely new in this country, invert from their usual position, and suspend them between the framing, the trunnion-pipes or steam-ways being placed at the end, or what in the ordinary engine would be termed the bottom of the cylinders. By these means a direct motion is applied to the crank without the intervention of cross-heads, side-rods, or parallel motion; the piston-rod being attached to the crankpin, the cylinders vibrating with the pendulous movement on their bearings or trunnions, whilst the oscillation of the cylinders works the slides by means of a bar. These engines are capable of exerting a power of fifty per cent. more than the power at which they are rated.

Fig. 217, No. 1.

required, well adapted for barn works, chicory and wood works, flour-mills up to three pairs of stones, for draining low-land from 1 to 2,000 acres, according to their level, for saw-mills, bone-mills, etc. It is fixed on a cast-iron sole plate, firmly bolted down to masonry, and can be easily removed, if required. Engines of this construction are made from two to eight-horse power, with or without governors, felted and cased, with water and pressure gauge, at from £150 to £300 each. An engine of this description has been at work in a printing-office, where it was used for driving two large cylinder machines: it answered its purpose admirably, and was seldom out of order.

Messrs. Lynch and Inglis, of Manchester, exhibited a portable steam-engine, represented in fig. 219, and of a stationary steam-engine, represented in fig. 220. For purposes where a small amount of power is required, such as crushing seeds, hoisting goods, pumping water, etc., these engines are peculiarly adapted. They are portable without sacrificing the proper proportions of their several parts; they are recommended by the simplicity of their construction, there being no more working parts than are absolutely necessary to communicate the required motion; the strain caused by the angle of the crank is entirely removed from the piston-rod; a long connectingrod is also obtained, and the crank shaft is brought down to the lowest point possible, so that the engine may be driven at a very high velocity, and yet remain perfectly steady. And, further to secure this desirable end, the fly-wheel is nicely balanced. Another great advantage may be observed in the

Fig.217, No. 2.

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SIDE ELEVATION,

From the simplicity of the engine there is no risk of derange- | ment, and the friction of the working parts is diminished three-fourths, whilst the consumption of fuel is less than 3lb. per horse power per hour, and there is a saving of one-half the space usually occupied by the ordinary steam-engines. Messrs. W. Joyce and Co. first commenced manufacturing these engines in 1834, since which period they have been erected in large numbers.

Me srs. Tuxford, of Boston, exhibited an improved noncondensing table-engine, which is represented in fig. 218, useful for driving heavy machinery, where a stationary engine is

FRONT ELEVATION.

long slide-valve, which not only effects a saving of steam, and consequently of fuel also, but ensures greater accuracy and durability, which are points of no mean importance in an engine intended to be placed in the care of men not at all, or very partially, acquainted with the construction of steamengines. The inside packings are all metallic, so that the trouble and annoyance of frequently taking the engine asunder is entirely avoided. The time is not far distant when the farmer, warehouseman, and shopkeeper, will call in the aid of these useful auxiliaries to perform that labour which is now but imperfectly accomplished by man.

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