Steam engine Denis Papin Smeaton, too Why Watt? Heat engines Commentary

James Watt thermodynamics

Steam engine

• James Watt didn’t invent the steam engine;
• he improved the Newcomen engine.
• Newcomen didn’t invent it either;
• Newcomen combined a vacuum, created by cooling steam,
• from Thomas Savery, with a piston from Denis Papin.
• The Newcomen engine rocked a beam up and down,
• suitable for operating a pump.
• Actually, the idea of harnessing steam is ancient.
• Archimedes invented a steam cannon in 212 BCE;
• Leonardo da Vinci invented another steam cannon around 1485,
• when it was called an architonnerre.
• Heron’s aeolipile, in 70 AD,
• was a simple steam turbine that did no work,
• but Gerbertus powered an organ with steam in 1125.
• More recently,
• Taqi al-Din invented a steam jack in 1551;
• Jerónimo de Ayanz y Beaumont a steam pump in 1606;
• Giovanni Branca a steam turbine in 1629;
• John Wilkins a steam jack in 1648;
• and Edward Somerset a water pump in 1663,
• which simply used steam-pressure to drive water up a pipe.
• To improve the Newcomen engine,
• Watt added a separate condensation chamber,
• injected steam into the upper part
• of the cylinder during the cooling cycle
• (called a “double acting” engine),
• and geared the engine for rotary motion.

Denis Papin

• Denis Papin had collaborated with Christiaan Huygens
• on a piston-and-cylinder engine driven by exploding gunpowder.
• They gave up on that project, but it taught Papin about pistons.
• Working with Robert Boyle in 1680, Papin invented the safety valve
• and the first pressure cooker, which they called the “steam digester”
• because it was used for rendering fat and softening bones before grinding.
• Having learned from his steam digester, in 1690 Papin created
• a model steam engine that raised a weight from the condensation of steam.
• In 1704, Papin installed one of his engines in a ship to move its paddles.
• This was another first. And in 1705, working with Gottfried Leibniz
• and influenced by Thomas Savery, Papin developed an engine that used
• steam pressure rather than atmospheric pressure, yet another first!

Smeaton, too

• John Smeaton created the equation
• for lift, with the coefficient of drag
• that the Wright brothers used
• and had to correct.
• Smeaton also improved the seals
• of the Newcomen steam engine
• and developed a theory of how
• a steam engine operates.

Why Watt?

• Credit goes to James Watt
• for inventing the steam engine
• because using a separate condenser
• and harnessing both vacuum and pressure
• radically improved the efficiency
• of the steam engine, and his rotary
• gearing improved its usefulness.
• But all this wasn’t enough. Watt’s
• commercial success came about
• because Matthew Boulton became
• his business partner after Watt’s
• original partner, John Roebuck,
• defaulted. The practical and commercial
• success of the steam engine
• helped bring on the social and economic
• changes of the industrial revolution.

Heat engines

• A steam engine is a heat engine.
• It converts heat into mechanical energy
• like an internal combustion engine
• or the earth’s atmosphere and hydrosphere.
• It would be tempting to say that life itself
• is also a heat engine, and many have argued
• one way or the other, which boils down to whether
• living things have free will or are merely
• driven by things they can’t control.
• I imagine Samuel Johnson arguing the matter
• by kicking a stone across a cobblestone street
• and asking, “Do I bounce like a stone?”