Part 14 (1/2)

When the wheels slipped in consequence of the presence of grease, frost, or moisture on the rail, Hedley proposed to sprinkle ashes on the track, as sand is now distributed froine This was in October, 1812

Hedley noent to work building an engine with sn March 13, 1813, a ine at work The locole steam-cylinder 6 inches in diaine had too sine, with a return-flue boiler ons 5the work of 10 horses The steam-pressure was carried at about 50 pounds, and the exhaust, led into the chimney, where the pipe was turned upward, thus secured a blast of considerable intensity in its s of the exhaust-pipe to intensify the blast, and was subjected to so his railere irritated by the burning of their grass and hedges, which were set on fire by the sparks thrown out of the chimney of the locomotive The cost of Hedley's experiment was defrayed by Mr Blackett

Subsequently, Hedley ines having been frequently stopped by breaking the light rails then in use Hedley's engines continued in use at the Wylaine was reton Museuenerally accorded the honor of having first ine at Killingworth, England, in 1814

[Illustration: George Stephenson]

At this time Stephenson was by nothe steaes on co, as has been seen, to attract considerable attention Stephenson, however, coreat natural inventive talent and an excellent ly of James Watt Indeed, Stephenson's portrait bears soreat inventor

George Stephenson was born June 9, 1781, at Wylam, near Newcastle-upon-Tyne, and was the son of a ”north-country reat mechanical talent and unusual love of study When set at work about the ence obtained for hie, he was ine at which his father was fireman

When a mere child, and eines in clay, and, as he grew older, never lost an opportunity to learn the construction andbeen eine-reater interest than ever the various steaine and the Watt puhly understood by hiton Quay, where he married, and cos per week It was here that he becauished Willia as an apprentice at the Percy Main Colliery, near by The ”father of the railroad” and the future President of the British association were accustoe works,” and were frequently seen in consultation over their nuton Quay that his son Robert, who afterward becaineer, was born, October 16, 1803

In the following year Stephenson reworth, and becaladly accepted an invitation to beco-mill near Montrose, Scotland At the end of a year he returned, on foot, to Killingworth with his savings (about 28), expended over one-half of the a his parents comfortable, and then returned to his old station as brakeman at the pit

Here he e his engine and planning newand repairing an old Newcoive satisfaction, hly successful after three days' work The engine cleared the pit, at which it had been vainly laboring a long time, in two days after Stephenson started it up

In the year 1812, Stephenson was100 a year, and it was made his duty to supervise the machinery of all the collieries under lease by the so-called ”Grand Allies” It was here, and at this period, that he commenced a systematic course of self-ian to be recognized as an inventor He was full of life and so applications of his inventive powers: as when he placed the watch, which a coht him as out of repairs, in the oven ”to cook,” his quick eye having noted the fact that the difficulty arose si of the wheels by the oil, which had been congealed by cold

Se as a perfect curiosity-shop, filled with ines, machines of various kinds, and novel apparatus He connected the cradles of his neighbors'

wives with the smoke-jacks in their chimneys, and thus relieved them froht with a subave hiive colloquial instruction to his felloorke and Robert Stephenson,” by Samuel S inclined plane for his pit, on which the wagons, descending loaded, drew up the eworth pit, that the nuround was reduced from 100 to 16

Stephenson now hadof the experiments of Blackett and Hedley at Wylaine He also went to Leeds to see the Blenkinsop engine draw, at a trial, 70 tons at the rate of 3 miles an hour, and expressed his opinion in the characteristic reo upon legs” He very soonlaid the subject before the proprietors of the lease under which the collieries orked, and convinced Lord Ravensworth, the principal owner, of the advantages to be secured by the use of a ”traveling engine,” that nobleman advanced the money required

Stephenson at once co it in the workshops at West Moor, assistedthe years 1813 and 1814, coine had a wrought-iron boiler 8 feet long and 2 feet 10 inches in diale flue 20 inches in diameter The cylinders were vertical, 8 inches in diameter and of 2 feet stroke of piston, set in the boiler, and driving a set of wheels which geared with each other and with other cogged wheels on the two driving-axles A feed-water heater surrounded the base of the chiradient of 10 or 12 feet to the ine proved in many respects defective, and the cost of its operation was found to be about as great as that of e horse-power

Stephenson deterine on a son in February, 1815 It proved a ine

[Illustration: FIG 51--Stephenson's Loco 51) was also fitted with two vertical cylinders, _C c_, but the connecting-rods were attached directly to the four driving-wheels, _W W'_ To permit the necessary freedom of motion, ”ball-and-socket” joints were adopted, to unite the rods with the cross-heads, _R r_, and with the cranks, _R' Y'_; and the two driving-axles were connected by an endless chain, _T t'_ The cranked axle and the outside connection of the wheels, as specified in the patent, were not used until afterward, it having been found iine the forced draught obtained by the i the power of theit possible to adopt the multi-tubular boiler Sine and served as springs

It was at about this tie Stephenson and Sir Humphry Davy, independently and almost simultaneously, invented the ”safety-lamp,” without which few mines of bituminous coal could to-day be worked The forauze, to intercept the fla with it directly into the inflaerous uished when the laed with the explosive mixture which had so frequently proved fatal to the miners This was in October and Novereat philosopher[52] The controversy which arose between the supporters of the rival claims of the two inventors was very earnest, and soineer raised a subscription, a to above 1,000, and presented it to him as a token of their appreciation of the value of his simple yet important contrivance Of the two forms of lamp, that of Stephenson is clai liable to produce explosions by igniting the explosive gas when, by its coauze cylinder, the latter is made red-hot Under siuished, as was seen at Barnsley, in 1857, at the Oaks Colliery, where both kinds of lamp were in use, and elsewhere

[52] _Vide_ ”A Description of the Safety-Lae Stephenson,” etc, London, 1817

Stephenson continued to study and experiment, with a view to the improvement of his locomotive and the railroad He introduced bettera half-lap, or peculiar scarf-joint, in place of the then usual square-butt joint He patented, with these modifications of the perine He had substituted forged for the rude cast wheels previously used,[53] and had ines built at this time (1816) continued in use ned for the purpose, he made experimental determinations of the resistance of trains, and showed that it wasfriction of the axle-journals in their bearings, the rolling friction of the wheels on the rails, the resistance due to gravity on gradients, and that due to the resistance of the air

[53] The American chilled wheel of cast-iron, a better wheel than that above described, has never been generally and successfully introduced in Europe