sion of the smooth wheels of a carriage, properly weighted, upon the smooth rails of the road. Six men were placed upon the frame, which was fitted up with windlasses attached by gearing to the several wheels. When the men were set to work the windlasses, Mr. Blackett found that the adhesion of the wheels on the smooth rails was sufficient to enable them to propel the machine without slipping. Having then found the proportion which the power bore to the weight, he demonstrated by successive experiments that the weight of the engine would of itself produce sufficient adhesion to enable it to drag after it, on a smooth tramroad, the requisite number of waggons in all kinds of weather. Thus was the fallacy which had heretofore prevailed on this subject completely dissipated, and it was satisfactorily proved that rack-rails, toothed-wheels, endless chains, and legs, were alike unnecessary for the efficient traction of loaded waggons upon a moderately level road.

As may readily be imagined, the jets of steam from the piston, blowing off into the air at high pressure while the engine was in motion, caused considerable annoyance to horses passing along the Wylam road, at that time a public highway. The nuisance was felt to be almost intolerable, and a neighbouring gentleman threatened to have it put down. To diminish the nuisance as much as possible, Mr. Blackett gave orders that so soon as any horse, or vehicle drawn by horses, came in sight, the locomotive was to be stopped, and the frightful blast of the engine thus suspended until the passing animals had got out of sight. Much interruption was caused to the working of the railway by this measure; and it excited considerable dissatisfaction amongst the workmen. The following plan was adopted to abate the nuisance: a reservoir was provided immediately behind the chimney, into which the waste steam was thrown after it had performed its office in the cylinder; and from this

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reservoir, the steam gradually escaped into the atmosphere without noise. This arrangement was devised expressly for the purpose of preventing any blast in the chimney, the value of which was not detected until George Stephenson, adopting it with a preconceived design and purpose, demonstrated its importance and value, -as being, in fact, the very life-breath of the locomotive engine.

* A drawing of the Wylam engine is given in the first edition of Nicholas Wood's Treatise on Railroads, 1825. The engine was placed on eight wheels, having seven rack-wheels working inside them, distributing the motion; while a barrel fixed behind the engine on two other wheels contained the water:-an exceedingly clumsy, uncouth-looking machine.

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CHAP. IX.

GEORGE STEPHENSON'S FIRST LOCOMOTIVES.

WHILE Mr. Blackett was thus experimenting and building locomotives at Wylam, George Stephenson was anxiously brooding over the same subject at Killingworth. He was no sooner appointed engine-wright of the collieries than his attention was directed to the more economical haulage of the coal from the pits to the river side. We have seen that one of the first important improvements which he made, after being placed in charge of the colliery machinery, was to apply the surplus power of a pumping steam-engine, fixed underground, for the purpose of drawing the coals out of the deeper workings of the Killingworth mines, by which he succeeded in effecting a large reduction in the expenditure on manual and horse labour.

The coals, when brought above ground, had next to be laboriously dragged by means of horses to the shipping staiths on the Tyne, several miles distant. The adoption of a tramroad, it is true, had tended to facilitate their transit; nevertheless the haulage was both tedious and expensive. With the view of economising labour, inclined planes were laid down by Mr. Stephenson, where the nature of the ground would admit of this expedient being adopted. Thus, a train of full waggons let down the incline by means of a rope running over wheels laid along the tramroad, the other end of which was attached to a train of empty waggons

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placed at the bottom of the parallel road on the same incline, dragged them up by the single power of gravity exceedingly economical mode of working the traffic. But this applied only to a comparatively small portion of the entire length of road. An economical method of working the coal trains, instead of by means of horses the keep of which was at the time very costly in consequence of the high price of corn, was still a great desideratum; and the best practical minds in the collieries were actively engaged in the attempt to solve the problem. Although Mr. Stephenson from an early period entertained and gave utterance to his sanguine speculations as to the "travelling engine," this was his first practical object in studying it, and endeavouring to make it an effective power; and he now proceeded to devote the entire energy of his strong practical intellect to the subject.

First, he endeavoured to make himself thoroughly acquainted with what had already been done. Mr. Blackett's engines were working daily at Wylam, past the cottage in which he had been born; and thither he frequently went, sometimes in the company of Nicholas Wood, to inspect Trevithick's patent engine, and observe the improvements which were from time to time made by Mr. Blackett, both in the locomotive and in the plateway along which it worked. He carefully inspected the "Black Billy," with its single cylinder and fly-wheel, its pumps, plugs, and spur gear. After mastering its arrangements and observing the working of the machine, he did not hesitate to declare to Jonathan Foster on the spot, his firm conviction that he could make a much better engine than Trevithick's one that would draw steadier and work more cheaply and effectively.

In the meantime he had also the advantage of seeing one of Blenkinsop's Leeds engines, constructed by Fenton Murray and Wood, of that town. The engine was a very

excellent piece of workmanship, and a great improvement upon the clumsy machines which Mr. Stephenson had inspected at Wylam. It was placed on the tramway leading from the collieries of Kenton and Coxlodge, on the 2nd of September, 1813; and a large concourse of spectators assembled to witness its first performances. This locomotive drew sixteen chaldron waggons containing an aggregate weight of seventy tons, at the rate of about three miles an hour. George Stephenson and several of the Killingworth men were amongst the crowd of spectators that day; and after examining the engine and observing its performances, he observed to his companions, as related by Heppel, who was present, that "he thought he could make a better engine than that, to go upon legs." Probably he had heard of the invention of Brunton, whose patent had by this time been published, and proved the subject of much curious speculation in the colliery districts. Certain it is that, shortly after the inspection of the Coxlodge engine, Stephenson contemplated the construction of a new locomotive, which was to surpass all which had preceded it. He observed that those engines which had been constructed up to this time, however ingenious in their arrangements, had proved practical failures. Mr. Blackett's were both clumsy and expensive. Chapman's had been removed from the Heaton tramway in 1812, and was regarded as a total failure. And the Blenkinsop engine at Coxlodge was found very unsteady and costly in its working; besides, it pulled the rails to pieces, the entire strain being upon the rack-rail on one side of the road. The boiler, however, having shortly blown up, there was an end of the engine; and the colliery owners did not feel encouraged to try any further experiment.

An efficient and economical working locomotive engine, therefore, still remained to be invented; and to accomplish this object Mr. Stephenson now applied himself. Profiting