ABSTRACT
The ancient philosophers and men of science in Persia and Greece understood the importance of heat in the scheme of things as their designation of it as one of four basic elements of the universe, that is, earth, air, fire, and water. The true utilization of heat as an energy source came with the development of the steam pump and the engine. Steam pressure was used to eject the water up a delivery pipe. The early mechanical engineers designed and built the first steam cycle engines without reference to any elaborate theory on heat engines. The reversible operation of the engine alone determined its efficiency in producing mechanical work. The marriage of scientific theory and engineering made for rapid evolution of this field during the 19th and 20th centuries. Wind power came in the form of post mills, smock and tower mill, whereby Britons pumped and ground. Post mills were the earliest design going back to medieval times.
