John Wilkinson

1728-1808

English Inventor

John Wilkinson is best remembered for developing the machine tools and techniques that helped make it possible to power the Industrial Revolution. By developing precision metalworking tools, Wilkinson was able to bore accurate, consistent cylinders for the steam engines under development by James Watt (1736-1819). These same techniques, it turned out, were also very useful in constructing cannons, pipes, and other similar devices.

Wilkinson was born in Clifton, England, in 1728, moving to Staffordshire at the age of 20. There, he helped build one of the first iron furnaces, making cast iron. Although cast iron is much stronger than native iron and is less brittle than wrought iron, it is difficult to work with. However, its superior material properties made the added effort worthwhile, while Wilkinson's furnace design helped make it affordable for a much larger group of people than had previously been the case.

Following this success, Wilkinson went to work at his father's factory in Wales. There, in 1775 he constructed his first cylinder boring machine, a device that could bore engine cylinders and cannon barrels more accurately than any previous such machine. In fact, existing boring machines were relatively crude, adapted as they were from wood-working tools and often used manually. By using better tools and mechanizing the process as much as was possible at the time, Wilkinson was able to produce borings that were remarkably precise, round, and consistent from one engine (or cannon) to the next.

Although this is a simple feat by today's standards, it was a phenomenal breakthrough in the eighteenth century. One of the major stumbling blocks in developing steam power was the fact that the cylinders leaked steam because they were not precisely round. The leaking steam, in turn, robbed the machines of efficiency, causing them to operate poorly. By making the borings precisely round and all the same diameter, Wilkinson's machine made it possible to coax more work out of the steam engines for the same cost in fuel. This, in turn, meant that more work could be gained for the same cost, a major improvement over previous practices.

As noted above, this same technology was also put to immediate use in boring cannon barrels. Like steam engines, cannons use the power of an expanding gas as a motive force; in this case, moving a cannonball out of the barrel at a high speed. Also like steam engines, a barrel that was not perfectly round threatened to cause the ball to bind, or resulted in gas leaking around it and robbing the shot of power. With more precise cannon barrels, balls (later shells) could be made to fit with closer tolerances in the knowledge that they would fit all cannon barrels, not bind while loading or being shot, and would get the most efficiency out of the load of powder. With more predictable characteristics from each cannon, artillery tables could now be drawn up that showed the distance a particular weight would be thrown for a given load of powder and elevation angle on the gun.

Other Wilkinson inventions included the world's first iron-hulled barge, used to transport the cannon barrels he manufactured, and the mating of Watt's steam engine to his boring machine to further automate the process of boring these pieces of equipment. At the same time, Wilkinson also worked with the French, teaching them to bore cannon barrels from solid iron and casting many miles of pipe and ironwork for the Paris waterworks.

Wilkinson died in 1808 at the age of 80. In accordance with his wishes, and very fittingly, he was buried in a cast-iron coffin he had designed some years earlier.

P. ANDREW KARAM