Stephenson often thought of the difficulties he had in life because of his lack of schooling. He was determined to give his only son Robert, born in 1803, a good education. As soon as Robert was old enough he was sent to the parish school. The education to be had there scarcely went beyond the primer and writing, and it soon seemed best to send Robert to Newcastle. This was expensive, and Stephenson's earnings were small. Besides, he was the sole support of his afflicted parents. How was the money to be obtained? "I betook myself," said Stephenson long afterwards, "to mending my neighbors' clocks and watches at night, after my daily labor was done, and thus I procured the means of educating my son."

Robert went to and from Newcastle on a donkey. But it was not only Robert who was at school at Newcastle, his father was also at school there. Their evenings were spent together in going over the lessons of the next day. Books were brought from the library to be read. When the desired books could not be taken out, Robert would bring home descriptions and sketches for his father's information. The son thus helped to educate the father—but such a father! Do you wonder that Robert was later proud of saying that if his success had been great, it was mainly to the example and training of his father that he owed it?

Stephenson as engine wright at Killingworth not only had to keep the pumping and hoisting engines in repair, but it was also part of his duty to look after all the other machinery. As he traveled from mine to mine, he was on the lookout to find where improvements could be made. Among other improvements, he began to think about a locomotive.

The locomotive was still looked upon as a curious and expensive toy. Stephenson saw more clearly than most others of what great use it might be, not only in carrying coal to market, but in transporting all kinds of products. He turned all his knowledge of machinery, and all the power of his inventive mind, to the making of a locomotive.

There are three parts to a railroad: the locomotive, the cars, and the track on which these run. The first railways were tramways, used to haul coal from the mines to the wharves, where it was loaded on boats to be carried to distant cities. Such tramways were often ten to a dozen miles long. They were constructed by building a roadway more or less level, and by placing, upon wooden crossties, two wooden rails. At some mines, a thin plate of iron was nailed on the upper surface of the rails. Cast-iron rails, three or four feet long, were also common.

The cars had a large hopper-like, wooden body. This huge body rested on a wooden platform made of heavy wooden beams. These were fastened at each end to an iron axle, which connected the two supporting cast-iron wheels. A horse could draw, at the rate of two or three miles an hour, two or more of these cars, when loaded altogether with from eight to ten tons of coal.

Two parts of a railroad, the rail or tramway and the cars, were thus at hand when Stephenson set himself to make a locomotive. His object was to invent an engine which would take the place of horses on the tramways. Hence, his locomotive to be successful must do the same work, not only more satisfactorily, but at less cost than it could be done by horses.

The idea of such a locomotive did not originate with Stephenson, nor was he the first to make one. That honor belongs to Richard Trevithick, who built a locomotive as early as 1804. This locomotive was able to haul ten tons, along with the cars, men, fuel, and the like, at the rate of five or six miles an hour. For a short time it was in successful use. But it broke so many of the small cast-iron rails of which the road was made, and ran off the track so often, that it was soon put aside and the engine degraded to working a pump. The trouble was with the track and not with the engine. With a little more perseverance, Trevithick might have succeeded in making a successful locomotive and have risen to fame and fortune. But Trevithick was a genius, fond of trying new projects. He left his locomotive, after a few trial trips, to take care of itself, and thought no more about it.

No one devoted much attention to the locomotive for some time. Still, the idea was not lost. In 1811, Mr. Blenkinsop, a mine manager near Leeds, decided to build one. Blenkinsop followed Trevithick's design. The big flywheel was, however, omitted, while the new features were the two cylinders and a toothed wheel working in a rack rail.

This toothed wheel and rack rail were contrived to overcome an imaginary difficulty. Even the wisest men of the time thought that if a load were placed behind an engine, the "grip" or "bite" of its smooth wheels on the smooth rails would be so slight that the wheels of the engine would spin round and round in the same place and the engine never move. Naturally, Blenkinsop thought that the toothed wheel working in a rack rail was necessary, if his engine was to draw a load.

Blenkinsop's locomotive, when loaded lightly, traveled at the rate of ten miles an hour. It would draw ninety tons at three and a half miles an hour on a dead level, or fifteen tons up grade. The locomotive cost two thousand dollars, and did the work of sixteen horses. For more than twenty years it was in constant use, and was the first successful locomotive ever made.

Encouraged by Blenkinsop's success, Mr. Blackett, of Wylam, resolved to try a locomotive at his mine. The first one made for him "flew all to pieces" on first trial. He had a second one built, which like the first was modeled after Trevithick's and Blenkinsop's engines. The new locomotive had a flywheel, and the driving wheel was cogged and traveled in a rack rail. This engine was able to haul eight or nine loaded cars at the rate of a mile an hour. It was too heavy for the track, and the rails were always breaking. The driver was asked one day how he got on. "Get on?" said he, "We don't get on; we only get off!"

The chief cause of the failure was the cogged driving wheel working in the rack rail. Blackett learned by experiment that these were unnecessary. His third locomotive, built in 1813, was fitted with 61 smooth wheels. This new engine, Puffing Billy, was more of a success. It was easy to manage, and drew ten to fourteen loaded cars, having a combined weight of twenty tons, at the rate of four or five miles an hour.

Stephenson's first engine, Blucher, was built in 1814. It was not much of a success. The best that Blucher  could do was to pull thirty tons on a grade, at the rate of four miles an hour. After a year's trial, it was found that it cost just as much to haul coal by steam power as by horse power. There was little encouragement in this, for the success of the locomotive depended on its economy.

Stephenson set to work with new vigor, and early in 1815 completed a second engine. This new engine had a wrought-iron boiler eight feet long and thirty-four inches through, with a single flue twenty inches in diameter. The flue was furnished with a steam blast. The steam blast or forced draft was one of Stephenson's wonderful inventions. In the earlier locomotives, the steam after doing its work in the cylinder was allowed to escape into the air, with a horrible hissing which terrified both man and beast. Stephenson noticed that the steam escaped with much greater speed from the cylinder than the smoke came from the smokestack. It occurred to him that if this escaping steam were turned into the smokestack, it would produce a draft. This, by increasing the intensity of the fire, would make it possible with the same size boiler to produce a greater amount of steam. The experiment was no sooner tried than the speed and the power of the engine were more than doubled. It is not too much to say that, without the forced draft, along with a boiler with a number of small tubes connecting the fire box and the smokestack, invented afterwards, locomotives might still be dragging along at a rate of not more than four or five miles an hour.

In Stephenson's first engine, the power was applied to the driving wheels by means of cogwheels. Stephenson saw that if the locomotive was to be a success, the power would have to be applied directly. In the new engine, the two cylinders were connected directly with the four driving wheels. To obtain the necessary freedom of motion, and to avoid the friction and jars due to rough places in the track, ball-and-socket joints were used to join the connecting rods with the crossheads of the cylinders, and with the crank pins of the driving wheels. Stephenson planned also to connect each pair of driving wheels by bars fastened to cranks in each axle. Workmen were, however, not able at this time to forge these cranks, and it was necessary, for the time being, to fall back on connecting chains.

Stephenson thus succeeded in making an engine having direct connection between the cylinders and the driving wheels, direct connection between all the wheels, and a forced draft. These are the essential points in all the engines which have been built since. Stephenson therefore accomplished for the locomotive, what Watt had done for the steam engine.