Using a piston in a cylinder, Otto von Guericke showed that when a vacuum was created on one side of the piston, the atmosphere would move the piston and a considerable mass through a distance, thus performing work. In 1672 he made a cylinder with a close fitting piston, all that strongly fixed in the vertical position.
By a rope and pulley 20 men effortlessly raised the piston to the top of the cylinder. Von Guericke had earlier prepared a large hollow sphere from which he had removed the air using a vacuum pump of his invention. When the sphere was connected to the cylinder atmospheric pressure pushed the piston down in spite of the efforts of the 20 men to restrain it. This demonstrated that the atmosphere was a potential source of energy but a vacuum was also needed to make use of it. No easy means existed of creating a vacuum except by a mechanical pump. This became the basic principle of the Newcomen steam engine (1712) i.e. the first practical device to harness the power of steam to produce mechanical work.
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