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 from the sand-box of the modern engine. This was in October, 1812.

Hedley now went to work building an engine with smooth wheels, and patented his design March 13, 1813, a month after he had put his engine at work. The locomotive had a cast-iron boiler, and a single steam-cylinder 6 inches in diameter, with a small fly-wheel. This engine had too small a boiler, and he soon after built a larger engine, with a return-flue boiler made of wrought-iron. This hauled 8 loaded coal-wagons 5 miles an hour at first, and a little later 10, doing the 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 small chimney. Hedley also contracted the opening of the exhaust-pipe to intensify the blast, and was subjected to some annoyance by proprietors of lands along his railway, who were irritated by the burning of their gra.s.s 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 mounted his engine on eight wheels, the four-wheeled engines having been frequently stopped by breaking the light rails then in use. Hedley's 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.

[Ill.u.s.tration: George Stephenson.]

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, as has been seen, to attract considerable attention. Stephenson, 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, near Newcastle-upon-Tyne, and was the son of a "north-country 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 fireman.

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 a.s.sociation 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 one-half of the amount in paying his father's debts and in making 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,[51] 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.

[51] "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 Killingworth 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 princ.i.p.al owner, of the advantages to be secured by the use of a "traveling engine," that n.o.bleman advanced the money required.

Stephenson at once commenced his first locomotive-engine, building it in the workshops at West Moor, a.s.sisted 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 feed-water 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 horse-power.

Stephenson determined to build another engine on a somewhat different plan, and patented its design in February, 1815. It proved a much more efficient machine than the "Blucher," the first engine.

[Ill.u.s.tration: FIG. 51.--Stephenson's Locomotive of 1815. Section.]

This second engine (Fig. 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 impossible to get the cranked axles made. In this engine the forced draught obtained by the impulse of the exhaust-steam was adopted, doubling the power of the machine and permitting the use of c.o.ke as a fuel, and making it possible to adopt the multi-tubular boiler. Small steam-cylinders, _S S S_, took the weight of the engine and served as springs.

It was at about this time that George 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 former used small tubes, the latter fine wire gauze, to intercept the flame. Stephenson proved the efficiency of his lamp by going with it directly into the inflammable atmosphere of a dangerous mine, and repeatedly permitting the light to be extinguished when the lamp became surcharged with the explosive mixture which had so frequently proved fatal to the miners. This was in October and November, 1815, and Stephenson's work antedates that of the great philosopher.[52] The controversy which arose between the supporters of the rival claims of the two inventors was very earnest, and sometimes bitter. The friends of the young engineer raised a subscription, amounting 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 claimed to be safest, the Davy lamp being liable to produce explosions by igniting the explosive gas when, by its combustion within the gauze cylinder, the latter is made red-hot. Under similar conditions, the Stephenson lamp is simply extinguished, 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-Lamp invented by George Stephenson," etc., London, 1817.

Stephenson continued to study and experiment, with a view to the improvement of his locomotive and the railroad. He introduced better methods of track-laying and of jointing the rails, adopting a half-lap, or peculiar scarf-joint, in place of the then usual square-b.u.t.t joint. He patented, with these modifications of the permanent way, several of his improvements of the engine. He had subst.i.tuted forged for the rude cast wheels previously used,[53] and had made many minor changes of detail. The engines built at this time (1816) continued in use many years. Two years later, with a dynamometer which he designed for the purpose, he made experimental determinations of the resistance of trains, and showed that it was made up of several kinds, as the sliding friction 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.

These experiments seemed to him conclusive against the possibility of the compet.i.tion of engines on the common highway with locomotives hauling trains on the rail. Finding that the resistance, with his rolling-stock, and at all the speeds at which he made his experiments, was approximately invariable, and equivalent to about 10 pounds per ton, and estimating that a gradient rising but 1 foot in 100 would decrease the hauling power of the engine 50 per cent., he saw at once the necessity of making all railroads as nearly absolutely level as possible, and, consequently, the radically distinctive character of this branch of civil engineering work. He persistently condemned the "folly" of attempting the general introduction of steam on the common road, where great changes of level and an impressible road-bed were certain to prove fatal to success, and was most strenuous in his advocacy of the policy of securing level tracks, even at very great expense.

Taking part in the contest, which now became a serious one, between the advocates of steam on the common road and those urging the introduction of locomotives and their trains on an iron track, he calculated that a road-engine capable of carrying 20 or 30 pa.s.sengers at 10 miles per hour, could, on the rail, carry ten times as many people at three or four times that speed. The railway-engine finally superseded its predecessor--the engine of the common road--almost completely.

In 1817, Stephenson built an engine for the Duke of Portland, to haul coal from Kilmarnock to Troon, which cost 750, and, with some interruptions, this engine worked on that line until 1848, when it was broken up. On November 18, 1822, the Hetton Railway, near Sunderland, was opened. George Stephenson was the engineer of the line--a short track, 8 miles long, built from the Hetton Colliery to the docks on the bank of the river Wear. On this line he put in five of the "self-acting inclines"--two inclines worked by stationary engines, the gradients being too heavy for locomotives--and used five locomotive-engines of his own design, which were called by the people of the neighborhood, possibly for the first time, "the iron horses."

These engines were quite similar to the Killingworth engine. They drew a train of 17 coal-cars--a total load of 64 tons--about 4 miles an hour. Meantime, also, in 1823, Stephenson had been made engineer of the Stockton & Darlington Railroad, which had been projected for the purpose of securing transportation to tide-water for the valuable coal-lands of Durham. This road was built without an expectation on the part of any of its promoters, Stephenson excepted, that steam would be used as a motor to the exclusion of horses.

Mr. Edward Pea.r.s.e, however, one of the largest holders of stock in the road, and one of its most earnest advocates, became so convinced, by an examination of the Killingworth engines and their work, of the immense advantage to be derived by their use, that he not only supported Stephenson's arguments, but, with Thomas Richardson, advanced 1,000 for the purpose of a.s.sisting Stephenson to commence the business of locomotive-engine construction at Newcastle. This workshop, which subsequently became a great and famous establishment, was commenced in 1824.

For this road Stephenson recommended wrought-iron rails, which were then costing 12 per ton--double the price of cast rails. The directors, however, stipulated that he should only buy one-half the rails required from the dealers in "malleable" iron. These rails weighed 20 pounds to the yard. After long hesitation, in the face of a serious opposition, the directors finally concluded to order three locomotives of Stephenson. The first, or "No. 1," engine (Fig. 52) was delivered in time for the opening of the road, September 27, 1825. It weighed 8 tons. Its boiler contained a single straight flue, one end of which was the furnace. The cylinders were vertical, like those of the earlier engines, and coupled directly to the driving-wheels. The crank-pins were set in the wheels at right angles, in order that, while one engine was "turning the centre," the other might exert its maximum power. The two pairs of drivers were coupled by horizontal rods, as seen in the figure, which represents this engine as subsequently mounted on a pedestal at the Darlington station. A steam-blast in the chimney gave the requisite strength of draught.

These engines were built for slow and heavy work, but were capable of making what was then thought the satisfactorily high speed of 16 miles per hour. The inclines on the road were worked by fixed engines.

[Ill.u.s.tration: FIG. 52.--Stephenson's No. 1 Engine, 1825.]

On the opening day, which was celebrated as a holiday by the people far and near, the No. 1 engine drew 90 tons at the rate of 12, and at times 15, miles an hour.

[Ill.u.s.tration: FIG. 58.--Opening of the Stockton and Darlington Railroad, 1815. (After an old engraving.)]

Stephenson's engines were kept at work hauling coal-trains, but the pa.s.senger-coaches were all drawn for some time by horses, and the latter system was a rude forerunner, in most respects, of modern street-railway transportation. Mixed pa.s.senger and freight trains were next introduced, and, soon after, separate pa.s.senger-trains drawn by faster engines were placed on the line, and the present system of railroad transportation was now fairly inaugurated.

A railroad between Manchester and Liverpool had been projected at about the time that the Stockton & Darlington road was commenced. The preliminary surveys had been made in the face of strong opposition, which did not always stop at legal action and verbal attack, but in some instances led to the display of force. The surveyors were sometimes driven from their work by a mob armed with sticks and stones, urged on by land-proprietors and those interested in the lines of coaches on the highway. Before the opening of the Stockton & Darlington Railroad, the Liverpool & Manchester bill had been carried through Parliament, after a very determined effort on the part of coach-proprietors and landholders to defeat it, and Stephenson urged the adoption of the locomotive to the exclusion of horses. It was his a.s.sertion, made at this time, that he could build a locomotive to run 20 miles an hour, that provoked the celebrated rejoinder of a writer in the _Quarterly Review_, who was, however, in favor of the construction of the road and of the use of the locomotive upon it: "What can be more palpably absurd and ridiculous, than the prospect held out of locomotives traveling _twice as fast_ as stage-coaches? We would as soon expect the people of Woolwich to suffer themselves to be fired off upon one of Congreve's ricochet-rockets, as trust themselves to the mercy of such a machine going at such a rate."

It was during his examination before a committee of the House of Commons, during this contest, that Stephenson, when asked, "Suppose, now, one of your engines to be going at the rate of 9 or 10 miles an hour, and that a cow were to stray upon the line and get in the way of the engine, would not that be a very awkward circ.u.mstance?"

replied, "Yes, _very_ awkward--_for the coo!_" And when asked if men and animals would not be frightened by the red-hot smoke-pipe, answered, "But how would they know that it was not _painted?_" The line was finally built, with George Rennie as consulting, and Stephenson as princ.i.p.al constructing engineer.

His work on this road became one of the important elements of the success, and one of the great causes of the distinction, which marked the life of these rising engineers. The successful construction of that part of the line which lay across "Chat Moss," an unfathomable swampy deposit of peat, extending over an area of 12 square miles, and the building of which had been repeatedly declared an impossibility, was in itself sufficient to prove that the engineer who had accomplished it was no common man. Stephenson adopted the very simple yet bold expedient of using, as a filling, compacted turf and peat, and building a road-bed of materials lighter than water, or the substance composing the bog, and thus forming a _floating_ embankment, on which he laid his rails. To the surprise of every one but Stephenson himself, the plan proved perfectly successful, and even surprisingly economical, costing but little more than one-tenth the estimate of at least one engineer. Among the other great works on this remarkable pioneer-line were the tunnel, a mile and a half long, from the station at Liverpool to Edgehill; the Olive Mount deep-cut, two miles long, and in some places 100 feet deep, through red sandstone, of which nearly 500,000 yards were removed; the Sankey Viaduct, a brick structure of nine arches, of 50 feet span each, costing 45,000; and a number of other pieces of work which are noteworthy in even these days of great works.

Stephenson planned all details of the line, and even designed the bridges, machinery, engines, turn-tables, switches, and crossings, and was responsible for every part of the work of their construction.

Finally, the work of building the line approached completion, and it became necessary promptly to settle the long-deferred question of a method of applying motive-power. Some of the directors and their advisers still advocated the use of horses; many thought stationary hauling-engines preferable; and the remainder were, almost to a man, undecided. The locomotive had no outspoken advocate, and few had the slightest faith in it. George Stephenson was almost alone, and the opponents of steam had secured a provision in the Newcastle & Carlisle Railroad concession, stipulating expressly that horses should there be exclusively employed. The directors did, however, in 1828, permit Stephenson to put on the line a locomotive, to be used, during its construction, in hauling gravel-trains. A committee was sent, at Stephenson's request, to see the Stockton & Darlington engines, but no decided expression of opinion seems to have been made by them. Two well-known professional engineers reported in favor of fixed engines, and advised the division of the line into 19 stages of about a mile and a half each, and the use of 21 fixed engines, although they admitted the excessive first-cost of that system. The board was naturally strongly inclined to adopt their plan. Stephenson, however, earnestly and persistently opposed such action, and, after long debate, it was finally determined "to give the traveling engine a chance." The board decided to offer a reward of 500 for the best locomotive-engine, and prescribed the following conditions:

1. The engine must consume its own smoke.

2. The engine, if of 6 tons weight, must be able to draw after it, day by day, 20 tons weight (including the tender and water-tank) at 10 miles an hour, with a pressure of steam on the boiler not exceeding 50 pounds to the square inch.

3. The boiler must have two safety-valves, neither of which must be fastened down, and one of them completely out of the control of the engine-man.

4. The engine and boiler must be supported on springs, and rest on 6 wheels, the height of the whole not exceeding 15 feet to the top of the chimney.

5. The engine, with water, must not weigh more than 6 tons; but an engine of less weight would be preferred, on its drawing a proportionate load behind it; if of only 4-1/2 tons, then it might be put only on 4 wheels. The company to be at liberty to test the boiler, etc., by a pressure of 150 pounds to the square inch.

6. A mercurial gauge must be affixed to the machine, showing the steam-pressure above 45 pounds to the square inch.

7. The engine must be delivered, complete and ready for trial, at the Liverpool end of the railway, not later than the 1st of October, 1829.

8. The price of the engine must not exceed 550.

This circular was printed and published throughout the kingdom, and a considerable number of engines were constructed to compete at the trial, which was proposed to take place October 1, 1829, but which was deferred to the 6th of that month. Only four engines, however, were finally entered on the day of the trial. These were the "Novelty,"