Imagini ale paginilor
PDF
ePub

engines continued in use at the Wylam collieries many years. The second engine was removed in 1862, and is now preserved at the South Kensington Museum, London.

GEORGE STEPHENSON, to whom is generally accorded the honor of having first made the locomotive-engine a success, built his first engine at Killingworth, England, in 1814. At this time Stephenson was by no means alone in the field, for the idea of applying the steam-engine to driving carriages on common roads and on railroads was beginning,

[graphic][merged small]

Ste

as has been seen, to attract considerable attention. phenson, however, combined, in a very fortunate degree, the advantages of great natural inventive talent and an excellent mechanical training, reminding one strongly of James Watt. Indeed, Stephenson's portrait bears some resemblance to that of the earlier great inventor.

George Stephenson was born June 9, 1781, at Wylam,

C

near Newcastle-upon-Tyne, and was the son of a “northcountry miner." When still a child, he exhibited great mechanical talent and unusual love of study. When set at work about the mines, his attention to duty and his intelligence obtained for him rapid promotion, until, when but seventeen years of age, he was made engineer, and took charge of the pumping-engine at which his father was fire

man.

When a mere child, and employed as a herd-boy, he amused himself making model engines in clay, and, as he grew older, never lost an opportunity to learn the construction and management of machinery. After having been employed at Newburn and Callerton, where he first became "engine-man," he began to study with greater interest than ever the various steam-engines which were then in use; and both the Newcomen engine and the Watt pumping-engine were soon thoroughly understood by him. After having become a brakeman, he removed to Willington Quay, where he married, and commenced his wedded life on 18 or 20 shillings per week. It was here that he became an intimate friend of the, distinguished William Fairbairn, who was then working as an apprentice at the Percy Main Colliery, near by. The "father of the railroad" and the future President of the British Association were accustomed, at times, to "change works," and were frequently seen in consultation over their numerous projects. It was at Willington Quay that his son Robert, who afterward became a distinguished civil engineer, was born, October 16, 1803.

In the following year Stephenson removed to Killingworth, and became brakeman at that colliery; but his wife soon died, and he gladly accepted an invitation to become engine-driver at a spinning-mill near Montrose, Scotland. At the end of a year he returned, on foot, to Killingworth with his savings (about £28), expended over onehalf of the amount in paying his father's debts and in mak

ing his parents comfortable, and then returned to his old station as brakeman at the pit.

Here he made some useful improvements in the arrangement of the machinery, and spent his spare hours in studying his engine and planning new machines. He a little later distinguished himself by altering and repairing an old Newcomen engine at the High Pit, which had failed to give satisfaction, making it thoroughly 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 was made engine-wright of the Killingworth High Pit, receiving £100 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-improvement and the education of his son, and here he first began to be recognized as an inventor. He was full of life and something of a wag, and often made most amusing applications of his inventive powers: as when he placed the watch, which a comrade had brought him as out of repairs, in the oven "to cook," his quick eye having noted the fact that the difficulty arose simply from the clogging of the wheels by the oil, which had been congealed by cold.

Smiles,' his biographer, describes his cottage as a perfect curiosity-shop, filled with models of engines, 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 from constant attendance upon their infants; he fished at night with a submarine lamp, which attracted the fish from all sides, and gave him wonderful luck; he also found time to give colloquial instruction to his fellow-workmen.

1 "Lives of George and Robert Stephenson," by Samuel Smiles. New York and London, 1868.

He built a self-acting inclined plane for his pit, on which the wagons, descending loaded, drew up the empty trains; and made so many improvements at the Kiilingworth pit, that the number of horses employed underground was reduced from 100 to 16.

Stephenson now had more liberty than when employed at the brakes, and, hearing of the experiments of Blackett and Hedley at Wylam, went over to their colliery to study their engine. 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 remark, "I think I could make a better engine than that to go upon legs." He very soon made the attempt.

Having laid the subject before the proprietors of the lease under which the collieries were worked, 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 commenced his first locomotive-engine, building it in the workshops at West Moor, assisted mainly by John Thirlwall, the colliery blacksmith, during the years 1813 and 1814, completing it in July of the latter year.

This engine had a wrought-iron boiler 8 feet long and 2 feet 10 inches in diameter, with a single 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 feedwater heater surrounded the base of the chimney. This engine drew 30 tons on a rising gradient of 10 or 12 feet to the mile at the rate of 4 miles an hour. This engine proved in many respects defective, and the cost of its operation was found to be about as great as that of employing horsepower.

Stephenson determined to build another engine on a somewhat different plan, and patented its design in Febru

ary, 1815. It proved a much more efficient machine than the "Blücher," the first engine.

This second engine (Fig. 51) was also fitted with two vertical cylinders, Cc, 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,

[graphic][subsumed][subsumed][subsumed][merged small]

Rr, 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 impossible to get the cranked axles made. In this engine the forced draught obtained by the impulse of the exhauststeam was adopted, doubling the power of the machine and permitting the use of coke as a fuel, and making it possible to adopt the multitubular boiler. Small steam-cylinders, SSS, took the weight of the engine and served as springs.

It was at about this time that George Stephenson and

« ÎnapoiContinuă »