Mighty SteamExpanding steam has great power, but learning to harness that power takes time. Early steam engines are large and clumsy. As they become smaller and more efficient, they provide a huge boost to businesses of all kinds. Soon, steam engines are mounted on wheeled platforms and called locomotives, pulling strings of carriages on smooth iron rails. As time goes on, the power of steam is adapted for many other purposes, from pumps to tractors. |
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Limitless Power (almost) When water boils in a tea kettle, it produces a jet of steam which is hot, but otherwise harmless (center top). In you contain the steam in a pressure cooker, however, the pressure of expanding steam continues to increase. As the temperature rises far above the normal boiling point, the cooker will explode unless the pressure is limited by a vent. A steam engine harnesses this pressure to perform work. Large boilers, like the ones used to power railroad locomotives, simply expand on this concept (lower right). | |||||||||
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Experimenting with Steam Early attempts to use steam engines to move carriages are often comical. Some designs put the boiler behind the carriage, and operate on regular streets. Most are simply a boiler on wheels, rigged up to pull some kind of carriage behind, on iron rails. The driving force is delivered by pistons, gears and even walking feet (lower right). It is a period of wild experimentation. But all these designs share the need to include a firebox, with a burning fire inside which needs constant tending. | |||||||||