James Watt was in many ways a typical product of the Scottish Enlightenment. He opened a shop near Glasgow University in 1757 in order to provide mathematical instruments to the students, and it was through this location that he met Joseph Black who developed the theory of latent heat. In 1764 he was asked to repair a working model of the Newcomen steam engine (invented 1704) and it dawned on him that the engine was made very inefficient by its cooling of the main cylinder in order to create the necessary vacuum to pull the piston up again after the down-stroke. If the cooling process could be located in a different place, then the engine would be much more energy efficient. Watt worked on this problem for five years supported by Joseph …
Clark, Robert. "Watt patents his steam engine". The Literary Encyclopedia. First published 10 February 2004; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1184, accessed 18 April 2015.]