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GEORGE STEPHENSON 289 rails hence "tramways." Over these tramways cars were drawn by horses, or by ropes from stationary engines. Murduck made a locomotive in 1784, and by 1 81 2 several types of engines were used for hauling coal-cars. Stephenson saw one of Blenkinsop's engines. Gear-wheels connected the crank-shaft with the axles, and the driving-wheels were geared with the track, while of course, the coal- cars ran on different rails. This Blenkinsop's engine was a fearful machine. All the teeth rattled, and as there were no springs and the road was very uneven, the shocks were heavy and frequent, even though its speed was only four miles an hour. Stephenson's first engine, " My Lord," in honor of his patron, Lord Ravens- worth, was finished in 18 14. Some experiments on the friction of smooth wheels on iron rails led him to omit the teeth on the drivers, though everyone laughed at him, declaring that the engine would not run an " up grade," much less draw a load. His faith, however, resisted all arguments ; it was based on experiments and careful calculations.' Stephenson knew that his engine would run up hill and draw a load, and it did so triumphantly. But the engine lacked steam. The boiler was small, and the fire was applied only on the exterior of the shell, and the draft was very poor, for the chimney was of necessity short. Only very low steam-pressure was possible, and little or no expansion was practicable. Consequently the exhaust was noisy and forcible. Stephenson turned it into the chimney and found that it increased the draft con- siderably ; he at once thought that a steady jet of steam could be so directed as to make a strong draft even when the engine was not in motion. Thus the " blast " was invented, which about doubled the capacity of the machine. Stephenson's second locomotive, built in 1815, had no noisy gears, but in- stead, chain-belts to the driving-axles. It had, however, no springs, and the shocks were so great that only a low speed was possible. In 18 16 he built locomotives with springs, some of which were in use for hauling coals for forty years. Meanwhile Robert was growing into a manly, useful lad. Knowing some- thing of the value of education, both of the head and of the hand, his father de- termined that Robert should have the best of both. He was sent to Edinburgh for scientific culture, and when at home his father taught him drawing, mechan- ical processes, and the theory of machines as far as he was able and his ability was considerable, for George Stephenson was more of a student than many whose early advantages were far better than his. The broad dual training given Robert appears to have been fully successful. Even before he became a man he was of great value to his father. Together they worked out plans for modi- fying and improving the locomotive and the road it was to run upon. He could soon draw and calculate better than his father, but he never excelled him in the solution of practical problems which depended upon a knowledge of materials and the simple laws of physics and mechanics. Thus far all railroads had been short, leading from mines to piers for ship- ping by water. The success of Stephenson's locomotive, the best working loco- 19