One of the great changes of the 1700s was the development of coal as an energy source. This allowed larger quantities of metal to be mined and smelted. Before 1750 metal was used almost exclusively for weapons or critical tools. When larger supplies of metal became available at lower costs due to coal one of the dreams this spawned was an interest in devices made out of metal--notably the steam engine. The idea behind the steam engine dates back to ancient times, but until bulk metal became available noone could reasonably build a steam engine. Once the forges of England began to churn with coal, however, many inventors eagerly worked on the development of the steam engine. There was still a problem though.

Even with plentiful supplies of metal the pressure in the piston was relatively low because it did not fit tightly. Consequently the engine was large (using up too much precious metal) for the amount of power it generated. There was an inverse relationship between the pressure in the piston and the amount of metal needed. This held back the steam engine until John Wilkinson provided the key enabling technology to James Watt in 1774: a boring mill. This tool was a kind of a lathe that produced tolerances of 1/16" on a 36" diameter piston cylinder. The steam engine became practical and the industrial revolution was born.

What exactly did (and does) the steam engine do? If you ask most people this question they will answer that it made possible locomotives, but this is a relatively minor relationship to the steam engine and only happened many years after the steam engine became widespread. The real importance of the steam engine was two-fold: it could power mining operations (lifting and pumping) and it could power factories. Before steam engines factories were run on water power, but water power was weak and unreliable. The steam engine made possible much larger and more powerful factories. The way it worked is that the steam engine would drive a central shaft and the factory would be full of machines that would be run by belts looped around the shaft. Until World War II and the spread of electricity all looms, presses and machine tools were powered this way.

The Steam Engine Wins the West

Having larger factories was a huge advantage in itself. For example, Eli Whitney used the steam engine to manufacture musket parts. Since all the parts were made in the same factory to the roughly the same specification using the same methods by the same people they were interchangeable. Until this time all guns were made one at a time by scattered, individual gunsmiths and each part in the gun would only fit that one gun. The steam engine essentially made it possible to mass produce guns. One of the effects of this was that American frontiersmen, outfitted with these guns overwhelmed the older and more established Spanish empire. California, Texas and Florida and the entire West were all conquered by 1850 at Spain's expense. To the Spaniards guns were precious and unique instruments only to be granted to authorized Spanish soldiers. Normal Mexicans and other Spanish citizens were (and still are) forbidden to possess guns. Contrast this to their opponents, a small group of pioneers who had a steam-engine-produced gun in every house and you can see why Spain lost.

Keyway Technologies

For the steam engine, itself an enabling technology, the critical tool was the development of a boring lathe. I call this a keyway technology; a small advance, but one which is critical to a much more significant development. Many inventors were working furiously on the steam engine, but it was only the keyway device that Watt had that turned the trick. History depends on these keyways, but for some reason they go unstudied.

One person who has perceived the importance of technology to civilization was the inventor of "Civilization" himself, Sid Meier. His innovative idea was to embody the progress of technology in his game Civilization which first appeared in 1991. In Civilization each technological advance depends on others. For example, before your civilization can research 'electricity' it must accomplish 'metallurgy' and 'magnetism'. Mastering the game requires learning its technology tree. Of course this tree is for a game and only roughly corresponds to reality, but maybe someday schools will teach real technology trees so that everyone will understand how civilization works.