ABSTRACT
The invention of Newcomen’s steam engine around 1710 marked the first time that humanity’s old friend fire could readily be harnessed to generate artificial power. Watt and Boulton engines that had replaced Newcomen’s design by the last decades of the eighteenth century combined the force of steam at slightly above atmospheric pressure with the vacuum generated by a condenser to move a piston within a cylinder. This, in turn, allowed some of the energy produced by the fire in the boiler to be transformed into mechanical force. A century or so later, when the first successful rotary steam engine was developed, the working principles remained essentially the same, even though the energetic steam was now at much higher pressure and was used to spin a turbine rather than to move a piston lengthwise within a cylinder. People had known about steam for thousands of years, but until Newcomen, Watt and Parsons, they had never been able to effectively harness it. Towards the end of the nineteenth century, in contrast, physicists were amazed to discover a completely new source of energy, one that appeared to emanate spontaneously from inside the atoms of some chemical elements.
