ton, and had communicated with Mr. Fulton on the subject. Thus at Helensburgh, in the firth of Clyde, nearly opposite to Greenock-the birth-place of the illustrious Watt-and at a distance only of six miles, originated the first practical application of the modern steam-engine to the purpose of navigation in Europe, and the invention, also, of his own countryman. Very soon after this period, steam-navigation by paddleSyming-wheels became general in Great Britain, and it thence extended over the Continent.

Fig. 209.

Fig. 210.

and three feet in stroke, and were adapted to drive the screw the engines may be wrought by this force of steam only, by propeller by direct action at sixty-five revolutions per minute. discharging the steam into the open air after it has done its A friend of Mr. J. P. Muirhead saw this model drive The object of the inventor of this modification of the steamengine, was to combine lightness and compactness relatively a small wagon round the room in Mr. Murdoch's house at to the power, along with simplicity of arrangement. These Redruth, in Cornwall. In a letter from Dr. William Small to Mr. Watt, dated engines, which are of the collective power of 700 horses, are September, 1786, he says: "Your very clever friend, Mr. Robison, and his pupil, passed Friday evening with me, to my great satisfaction. I told them I hoped soon to travel in a fiery chariot of your invention!" The tribute afterwards borne by Watt to the chief of these visitors was fully merited: "It was with great concern I learnt the other day the death of my worthy friend, Professor Robison. He was a man of the clearest head and the most science of any body I have known, and his friendship to me only ended with his life, after having continued nearly half a century." Mr. Muirhead states that among the persons who saw this "working model" at Mr. Murdoch's was Mr. Richard Trevethick, who, in 1802, took out a patent for an engine to be applied to the driving of carriages, using the same principle with variations.

constructed so that they can be placed in the ship entirely below the water-line, whereby they are protected from the effect of shot in war-vessels; and in the mercantile marine service, they leave the decks clear for passengers and cargo. The same exhibitors showed in the Exhibition two working models made in 1785, by Mr. William Murdoch, of Soho, the inventor of the method of illuminating our streets by coal-gas, who was at that period connected with the firm of Messrs. Boulton, Watt and Co. The first of these models is represented in fig. 211; it is that of a "locomotive," showing the

Fig. 211.

It is interesting to examine this model, in connexion with those complex, and in some instances, stupendous machines, of which the Exhibition supplied so many beautiful examples. Franklin said of the first balloon:-"It is a 'babe,' but it may become a giant." The balloon, however, is a "babe "still; while the locomotive presents to it a most striking contrast; if, in this model, we have "the babe," "the giant" is at hand inviting our contemplation. But it appears that the idea of a rail never entered the mind of Watt; all that he seems to have considered was, the movement of a carriage by steam on ordinary roads.

The second model exhibited by Messrs. J. Watt and Co. was that of an "oscillating engine," constructed at that early period, for the purpose of illustrating Mr. Watt's patent of 1784, for making the cylinder work on its axis. For the representation of this model, see fig. 212.

original application of steam for the purposes of travelling; and it was tried by the maker of it upon the common road in Cornwall in 1785 and 1786.

Mr. Murdoch was a man of great ingenuity. Of this there is sufficient proof in his paper in the "Philosophical Tran actions" for 1808, on "The Application of Gas from Coal to Economical Purposes," for which the Royal Society presented him with the large Rumford gold medal. He had previously proved, for many years, a most able and zealous agent in carrying out the plans of Messrs. Boulton and Watt, in the introduction of their engines into Cornwall; and afterwards in the construction and carrying forward their works at Soho. Watt refers, in one of his works, to several of Murdoch's very ingenious inventions, and also to his construction of tools for the manufacture of machinery. In these circumstances he made the model now referred to, the first locomotive ever applied to the drawing of carriages, as described in the specification of Watt's patent. "I intend, in many cases," said that eminent man, "to employ the expansive power of steam to press on the piston. In cases where cold water cannot be had in plenty,

The name of this engine is derived from the cylinder being made to oscillate, so that the important purpose of saving room may be gained. To understand this, let it be observed that, when a cylinder is fixed, the piston-rod can only describe a right line, and, consequently, there must be some intermediate mechanism between the piston-rod and the crank, as the latter describes a circle. But this mechanism requires space, which is greatly saved when the cylinder is made to oscillate, as the piston-rod can be attached at once to the crank. This

arrangement 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 Wester.i 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 circum stances, 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

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 This system, as may be imagined, is best suited for main making steam-walking machines, in which iron legs and feetlines, where the traffic is very heavy. It had, however, been were employed to push the engine along. George Stephenson, foreseen by some of our engineers that the rage for the heavy 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 their eyes became open to the fact that more than half its that time we may date the introduction of the locomotive power was exerted in moving itself merely, and knocking the system. When the Liverpool and Manchester Railway was rails and sleepers to pieces, they were as anxious to get back projected in 1823, Mr. Stepheson and others spent large sums their light engines as they had formerly been to discard of money in improving the details of the engine; so that on them. This led to the introduction of the light "locomotive the opening of that railway a very excellent performance was carriage" of Mr. Adams, and the light engine of Mr. England. at once attained, and the benefits of the railway system began The specimens which they exhibited, whilst possessing all the to be appreciated. The great superiority of the engines used advantages which experience and skill have worked out in the on this line over that just described arose from the use of a heavy engines, are not more than one-third of the weight and boiler containing a number of tubes or small flues, through half the cost. Mr. Adams' plan consists in combining the which the flame passed, and which generated steam much more engine and carriage in one, so that there is no superfluous rapidly than the former boiler with a single large tube through it. weight. The boiler is a cylinder full of tubes placed vertiSince that date, the increase of power that has taken place cally; but this plan, in subsequent engines, has been given up

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

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