Around the turn of the third millenium, people thought about what a shortlist of the most significant inventions of the second millenium(1001-2000) wouldnecessarily entail...
Herb Brody (Technology Review senior editor) came upwith the following list, in chronological order: compass, clock, lens, printing press,steam engine, telegraph,electrical power, radio, antibiotics, and transistor. That's just about it. Improvements and applications of those great inventions wereruled out, including the telephone, television, computer and other consumer electronics. (So was the PN junction, which is overshadowed by its offspring, the transistor.)
The internal combustion engine did not make the list either,because it isperceived as an improvement over the steam engine,at least by nontechnical people. However, the internal combustion engine is a radically new technical idea,transcending fundamental limitations of steam engines. Simply put,some chemical energy is directly put to workin an internal combustion engine, whereas all of it is first transformed into heatin a steam engine... The fundamental difference is the push providedby a chemical explosion. The French have a better term for the internal combustion engine:moteur à explosion.
To realize how important this is, you have to gain some exposure to the fundamentalsof steam engines, which were poorly understood for centuries, untilthe theory ofthermodynamics and its infamoussecond lawwere discovered. Thesecond law was first stated to explain the limitedefficiency of steam engines, but it ultimately explainsa lot more about the Universe around us andwithin us...
What follows is a guided tour through this fascinating history ofpractical inventions and theoretical discoveries. From water pumps to the elusive idea ofentropy...
Heat Engines and the Fate of the Universe
(2004-02-15) Greatest ball of water wind and fire on Earth
The first documented steam engine was merely a toy. It consisted of a boiler whose steam was routed through hollow supportsinto a spherical chamber, which rotated on a polar axis as steam escaped from twojet tubes along the equator.
This isdescribed,with many other pneumatic or hydraulic devices, in Spiritalia seu Pneumatica by Hero / Heron of Alexandria (c.AD 10-75).
The termaeolipile (Frenchéolipyle, LatinAeoli pylae = ball of Aeolus) may have been coined in the 17th century, when other engines appeared.
Some authors have attributed to an earlier prolific inventor called Ctesibius many of the contraptions described by Heron (who offers no clues on the matter). The aeolipile may or may nothave been the work ofCtsibius. Heron himself is much better known for theformulanamed after him, which schoolchildren use to find the areas of scalene triangles.
(2005-06-26) A blueprint for a steam-powered fountain (1662).
Edward Somerset was known asLord Herbert after 1628. In 1644, he became earl of Glamorgan, before inheriting thetitle of sixth earl and second marquis of Worcester, in 1646.
Worcester published his design but apparently never builtan actual steam engine. He proposed using the partialvacuum created when steam condensesto obtain mechanical work from atmospheric pressure. This was the key idea used byNewcomen inhis successful atmospheric engine, half a century later.
(2004-02-15) Beyond the pressure cooker: The first actual piston engine (1690).
The Frenchman Denis Papin invented the pressure cooker A pressure cooker is a heated closed container. Food cooks faster in it because the temperature of water can be higher than the boiling point under ordinary atmospheric pressure. A critical feature of the pressure cooker is, of course, its safety valve.
In 1690, Papin had the idea of fitting a piston over a boilerwith a limited amount of water in it. When the boiler is heated, water becomes steam and the piston ispushed upward. When the boiler is allowed to cool, the steam condenses and atmosphericpressure pushes the piston down, back to the original volume.
Although considerable forces can be involved, the power of Papin's engine islow, because the heating and cooling of a single chamber is a slow process.
The English engineer Thomas Savery built an engine consistingof two pistons over copper vessels which were alternately fed with steamfrom a separate boiler.
This high-pressure engine could raise water about 20 feet (6 m). Thomas Savery obtained several patents beforeThomas Newcomen made his own entrance. (At some point, Savery may have employed Newcomen,whose blacksmith shop was only15 miles away from Savery's residence at Modbury.)
Thomas Newcomen was an English blacksmith born in Dartmouth (Devonshire)who set up shop there in 1685,in partnership with a plumber named John Calley[also spelled "Cawley"] (d.1717) who shared his interest in engines.
In 1698, Newcomen started corresponding withThomas Saveryand attempted to improve on Savery's machine to produce a safe andreliable steam engine.
In 1708, Newcomen obtained a patent(jointly withSavery)for what's usually considered to be thefirst practicalsteam engine. The use of low-pressure steam (5 psi) made it extremely safe. The key idea was to spray cold waterinside the piston'schamber when is was filled with steam. This caused steam to condense rapidly, andthe atmosphere pushed the piston back to a smaller volume.
In 1712, the first operational engine was built overa mine nearDudley Castle. It ran at 6 to 8 strokes per minute, with manual valves. Automatic valves later allowed a typical regime of 10 to 12 rpm.
Newcomen's engine was successfully used to pump water from coal minesthroughout Europe. It was even exported to North America in 1755.
Joseph Cugnot was a French military engineer. Ostensibly, he designed his fardier à vapeur (steam dray) for the purpose of hauling artillery pieces.
Thesecond prototype, which was completed by June 1771,is religiously preserved in Paris, at theConservatoire National des Arts et Métiers.
(2004-02-15) The steam engine comes of age: Steam condenserandgovernor.
The water-cooledsteam condenser, patented by James Watt in 1769,was the key to a dramatic improvement in the efficiency of steam engines.
Although the fundamental issue was not fully understood until 1824 (seeCarnot's limit below) this improved efficiency came from a greater temperature difference [orratio, rather] between active parts of the enginethroughout its cycle.
Watt's engine has two separate chambers: Thepiston's cylinder remains at the temperature ofhot steam, while thesteam condenser is water-cooled.
Among many other innovations,Watt also introduced an ingenious speed regulator in 1788,which is probably the earliest technological example of afeedback mechanism: The so-called Watt governor (also known as thecentrifugal orflyball governor)made steam engines safer and easier to use.
By 1790, the new and improved Watt engineshad all but completely replaced Newcomen engines. Watt's clever innovations were so successfull that it's nownecessary to stress that James Watt did not invent the steam engine!
(2005-06-26) The inventor of the railroad locomotive was not George Stephenson.
In 1796, Richard Trevithick experimented with high-pressure noncondensingsteam engines and built his first miniature locomotive. OnChristmas eve of 1801, he took 7 of his friendson a trip aboard a "road locomotive". He is credited with the idea that smooth wheels on smoothiron rails would provide enough traction for most practical purposes.
In February 1804, Trevithick tested the first locomotive ever torun on rails. This locomotive featured a single vertical cylinder, an 8-foot flywheeland aninnovative exhaust steam chimney (producing an efficient updraft). It hauled 5 wagons, 10 tons of iron and 70 passengers,but made only 3 short trips on a projected 9-mile railroadbetween the Merthyr-Cardiff Canal and the ironworks at Pen-y-darren (whose owner, Samuel Homfray, was financing the enterprise). Each time, the locomotive broke some cast-iron rails. The sponsor gave up.
George Stephenson himself stressed the importance of theexperiments of Trevithick in the development of locomotives. However, in February 1828, the House of Commonsdenied a pension to Trevithick, who died in poverty.
The immediate successors to the Trevithick locomotives were usedin mining operations. This included the Blutcher locomotive, builtin 1814 by the British engineerGeorge Stephenson (1781-1848). In 1829, the Liverpool and Manchester Railroad ran alocomotive competition for a railway intended to carry both passengers and freight. The trials took place at Rainhill, near Liverpool, in October 1829. The award went to Stephenson, for a legendary locomotive named Rocket.
(2005-06-23) Fundamental limitations: Thesecond law of thermodynamics.
After the dramatic innovations of James Watt, many engineers wonderedif anything could be done to further increase the low efficiencyof steam engines. By offering a sobering upper limit to that efficiency,a young Frenchman helped create the new science of thermodynamics: In 1824, [Nicolas Léonard] Sadi Carnot analyzed an ideal enginetransforming into work some of the heat going from a hot source to a cold one...
Carnot defined the efficiency of an heat engineas the ratio of the net work doneby the engine to the heat it received from its boiler (whatever heat is spend by the engine to warm up the condenser is,indeed, pure waste).
This efficiency can't exceed the following function of the hot (T1 ) and cold (T0 )temperatures above absolute zero, known as Carnot's limit :
1 T0 / T1
The unavoidable "waste" is thus equal to the ratio of the absolute temperatures. This example was ultimately generalized into what became the Second Law of Thermodynamics, evenbefore the First Law was generally accepted.
Carnot's limit is not directly applicable to an internalcombustion engine, which may involve some direct transformationof chemical energy into mechanical work.
(2005-06-22) Steam turbines (1884) are still used in nuclear power plants.
In 1629, Italian engineer Giovanni Branca (1571-1640) rana double-pestle stamp mill with a steam blower (directing a jet to vanes on a wheel).
In 1791, the British inventor John Barber obtained a patent for a gas turbine.
In 1884, Charles Parsons (6th son of the 3rd earl of Rosse)patented the modern steam turbine, with multiple staging. Each stage in such a turbine improves overall efficiency by makinguse of the steam of the previous stage and is optimized for itstask in this chain of successively lower steam pressures. Parsons' first prototype produced about 10 hpat 20000 rpm (by contrast, a reciprocating steam engine islimited to about 1500 rpm, at best).
In 1887, the Swedish engineer Carl Gustaf Patrik de Laval (1845-1913)built a small demonstration steam turbine which rotated at 42000 rpm. In 1890, he invented the convergent-divergent nozzle now named after him,to optimize the efficiency of a single-stage steam turbine (thede Laval nozzle is commonly used in modern rocketry). De Laval also came up with innovative reduction gearing which couldaccomodate the high rotational speed of steam turbines.
Turbinia :
Although he had no training as a naval architect, Parsons designed and builtTurbinia,the first ship ever to be powered by steam turbines. He demonstrated her astounding speed on June 22, 1897, during Queen Victoria's Diamond Jubilee Fleet Review. Parsons piloted the ship himself, at the astounding speed of 34.5 knots (64 km/h, 40 mph). Charles Parsons was knighted in 1911.
(2011-08-31) A clever heat engine based on evaporative cooling.
The very popular book "Physics for Entertainment" by Yakov Perelman (1882-1942) was first published in 1913 and was last revised by its original author in 1936. It went through 18 Russian editions beforebeing translated in English (in 1975, volume 2 only). Onpp. 226-228 of that translation,the insatiable birdie is discussed as an interesting "Chinese toy" (its exact origin is unknown, to the best of my knowledge).
The drinking bird waspatented in the US by Miles V. Sullivan in 1946. The son of Miles Sullivan has confirmed thatAlbertEinstein could not figure out the operating principle of the toy when he wasfirst confronted with it (in 1922). Neither could most physicists...
The fluid contained in the vessel (which is usually colored) must have a fairly high vapor pressure at roomtemperature. The US patent (1946) mentions "ether,alcohol,carbon tetrachloride orchloroform". Formerly, the toy was manufactured with trichloromonofluoromethane (Freon-11) before its harmful impact on the environment was recognized. Nowadays,dichloromethane ismost commonly used (it's a moderately hazardous substance heralded asthe least toxic of the simpleorganochlorides).
Homer Simpson
