George Henry Corliss was another mechanical genius, who, in one respect, anticipated Howe, for about 1842 he actually invented a machine for stitching leather. That was two years before Howe made his discovery. But Corliss was soon attracted to other work, and the development of the sewing machine was left for the other inventor. It was in 1846 that Corliss began to develop those improvements in the steam engine which were to revolutionize its construction. One trouble with the steam engine as then built was that it was not uniform in motion. That is, if the engine was running a lot of machines their speed would vary from moment to moment, as they were started or stopped. For instance, a hundred looms, all running at once, would run at a certain speed, but if some of them were shut off, the speed of the others would increase, so that it was very difficult to regulate them. Again, there was a tremendous waste of power, so that the fuel consumption was out of all proportion to the power actually developed. It was these defects that Corliss set himself to remedy, and he did it simply by taking a load off the governor, which had always been used to move the throttle-valve. In the Corliss engine, the governor simply indicated to the valves the work to be done, and the saving of fuel was so great that the inventor often installed his engine under a contract to take the saving in coal-bills from a certain period as his pay. One of his great achievements was the construction of a 1400 horse power engine to move all the machinery at the centennial exposition at Philadelphia, in 1876. The engine, which worked splendidly, was one of the sights of the exposition. What the sewing-machine is to the needle, the typewriter is to the pen. No other one invention has so revolutionized business, and the credit for the invention of a practicable typewriting machine is due to C. Latham Sholes. Others had tried their hands at the problem before he took it up, but he was the first to hit upon its solution--a number of type-bars carrying the letters of the alphabet operated by levers and striking upon a common centre, past which the paper was carried on a revolving cylinder.