About this time a new pit having been sunk in the district where he worked, the engine fixed for the purpose of pumping the water out of the shaft was found a failure. This soon reached George's ears. He walked over to the pit, carefully examined the various parts of the machinery, and turned the matter over in his mind. One day when he was looking at it, and almost convinced that he had discovered the cause of the failure, one of the workmen came up, and asked him if he could tell what was wrong. "Yes," said George; "and I think I could alter it, and in a week's time send you to the bottom." George offered his services to the engineer. Every expedient had been tried to repair the engine, and all had failed. There could be no harm, if no good, in Stephenson trying his hand at it. So he got leave, and set to work. He took the engine entirely to pieces, and in four days had repaired it thoroughly, so that the workmen could get to the bottom and proceed with their labours. George Stephenson's skill as an engine-doctor began to be noised abroad, and secured him the post of engine-wright at Killingworth, with a salary of L100 a-year. Robert was now old enough to go to school, and was sent to one in Newcastle, to which, dressed in a suit of coarse grey stuff cut out by his father, he rode every day upon a donkey. Robert spent much of his spare time in the Literary and Philosophical Institute of Newcastle; and would sometimes take home a volume from the library, which father and son would eagerly peruse together. Occasionally they tried chemical experiments together; and now and then Robert would try his hand by himself. On one occasion he electrified the cows in an adjacent enclosure by means of an electric kite, making the bewildered animals dash madly about the field, with their tails erect on end; and another time he administered a severe electric shock to his father's Galloway pony, which nearly knocked it over, and drew down upon him the affected wrath of his father, who, coming out at the instant, shook his whip at him and called him a mischievous scoundrel, though pleased all the while at the lad's ingenuity and enterprise. As an early proof of the former, there still stands over the cottage door at Killingworth a sun-dial, constructed by Robert when he was thirteen years old, with some little help from his father.