The Road to Entropy – Phil Hosken on Richard Trevithick and the invention of the high-pressure steam engine (video)

As shared in my previous post (here), the historical road to entropy started with Denis Papin’s development of the piston-in-cylinder assembly and Thomas Newcomen’s and James Watt’s subsequent efforts to commercialize and continuously improve fire engines or atmospheric engines built around this assembly. Steam at atmospheric pressure was employed in these engines, not as a driving force but instead as a means to create a vacuum inside the cylinder (condensation via water spray), thus causing atmospheric air to drive the piston down into the cylinder and so generate useful work.

Around 1800 in Cornwall, England, Richard Trevithick transformed this technology by inventing an entirely new engine based on the (safe) use of pressurized steam as the driving force. Several technological breakthroughs were required, including the design and fabrication of the first shell-and-tube heat exchanger. The arrival of these steam engines, now accurately named, quickly attracted the entrepreneurial interests of other Cornish engineers, as these engines were proving themselves more efficient (quantified by work done divided by bushels of coal consumed) than those of Newcomen and Watt; rapid improvements followed, as best reflected by the eventual increase in steam pressure from 0 to 50 psig. Arthur Woolf commercialized one such improved design and his former business partner, Humphrey Edwards, brought the end product to France. The importance of this history? It was arguably Woolf’s design that inspired Sadi Carnot in 1824 to conduct the first theoretical analysis of the steam engine.

In the act of writing my book on this topic, I had the good fortune to connect with Phil Hosken. Phil lives in Cornwall and is an expert on the life and times of Richard Trevithick, having once served as President of The Trevithick Society. As Trevithick played such a critical role in this historical timeline, I invited Phil to prepare the short video shown above. I do think you’ll enjoy learning something new by watching this video and also think that questions will come to your mind. Phil gladly welcomes such questions so please do not hesitate to engage. His email is: His website is:

If you’re interested in a deeper dive, Phil wrote the following two books on Richard Trevithick.

Hosken, Philip M. 2011. Oblivion of Richard Trevithick. Cornwall, England: Trevithick Society.
Hosken, Philip M., 2013. Genius, Richard Trevithick’s Steam Engines. Place of publication not identified: Footsteps Press.

I go into more detail about Richard Trevithick and the rise of the pressurized steam engine in my book Block by Block – The Historical and Theoretical Foundations of Thermodynamics.

Published by Robert T Hanlon

I earned my Sc.D. in chemical engineering from the Massachusetts Institute of Technology and subsequently conducted post-doctoral research at Karlsruhe University in Germany. My professional career took me to Mobil Oil Research & Development Corporation, the Rohm and Haas Company, and then back to MIT where I am currently involved with their School of Chemical Engineering Practice.

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