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 A big improvement over these two types of transportation is mechanical power. Mechanical power is more efficient and portable than animal power. Steam engines were the first practical mechanical engines built. Hero of Alexandria built the first operating steam apparatus around the first century AD. It was called the aeoliphile, and had no practical purpose. It consisted of a hollow ball mounted on two metal tubes in such a way that the ball could turn, using the tubes as axles. Two additional tubes exited the ball, perpendicular to the axles. These tubes were bent at about a ninety degree angle. The axle tubes were connected to a boiler which supplied steam to the ball when the water in the boiler was heated. The steam exited the ball through the vent tubes, causing the ball to spin. The aeoliphile was considered a toy by the ancient world and no application was ever found for it. The first important step in mechanical power came in 1698. Coal was an important source of heat for homes and businesses at this time. Coal mines, since they are underground, have the unfortunate habit of collecting water from above ground. In pre-industrial times, removing this water was a major problem. A military engineer named Thomas Savery solved this problem with his invention of the steam powered suction pump. This pump, it was found, could also supply water to large buildings. The Savery pump, improvement that it was, was still very inefficient. Thomas Newcomen, another Englishman, devised a steam powered piston pump in 1712. It proved to be much more efficient than the Savery pump, but the apparatus was still limited to pumping water. James Watt was called on to repair a Newcomen engine in 1764. Seeing the limitations, he began working to improve the engine. His first innovation, which was the beginning of a twenty five year career of improvements on the steam engine, was to the condenser of the engine. Watt’s first improved engines were still limited to pumping water because their motion was reciprocating - or back and forth. The ‘sun and planet’ gear system he devised in 1781 gave the engine a rotary movement. This opened the door to many more applications for the engine. This was one of the most important developments in modern times. With the development of the steam engine from novelty to useful machine, the stage was set for the Industrial Revolution and improved methods of transportation. Soon the engines were powering factories turning out products. The rise of the railroad using steam powered locomotives forever changed the course of our history, allowing fast, convenient travel. Shipping became faster and more reliable with steam engines providing the power to cross vast oceans swiftly. The steam engine, because it was the first successful mechanical power system devised in our history was a very important invention. It fueled the Industrial Revolution, helped transport countless millions of people and tons of freight. It also tended to draw countries and continents together as the locomotive which followed allowed quicker, easier and cheaper transportation of long distances than had been possible before. |