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James Watt, Instrument Maker

11 points by cfmcdonald 5y ago

Animats 5y ago
It's amazing how long it took to get even the basics of thermodynamics figured out. You'd think some clockmaker would have made a little brass steam engine by 1600 or so. But no. Making a big engine with the necessary precision is hard, but a little demo-sized one was within the limits of 17th century clockmaking skill.
throw0101a 5y ago
I understand that the article's focus is Watt, but this throwaway line is bit disappointing: > Wilkinson’s cylinders, true to a circle with a variation of less than width of a shilling — about 1/10th of an inch — were sufficiently precise that Watt’s pistons could work without leaking a noticeable amount of steam. As much as Watt's engines were an improvement over Newcomen's in efficiency, I wouldn't be surprised if the 'Wilkinson-manufactured' engines were as much again a relative improvement by the same amount over the 'pre-Wilkinson' engines of Watt. * https://en.wikipedia.org/wiki/John_Wilkinson_(industrialist) https://en.wikipedia.org/wiki/John_Wilkinson_(industrialist) There's an entire chapter on the subject in the book The Perfectionists: How Precision Engineers Created the Modern World by Simon Winchester. From a review of the book by James Gleick: > Watt, meanwhile, had patented his steam engine, a giant machine, tall as a house, at its heart a four-foot-wide cylinder in which blasts of steam forced a piston up and down. His first engines were hugely powerful and yet frustratingly inefficient. They leaked. Steam gushed everywhere. Winchester, a master of detail, lists the ways the inventor tried to plug the gaps between cylinder and piston: rubber, linseed oil-soaked leather, paste of soaked paper and flour, corkboard shims, and half-dried horse dung—until finally John Wilkinson came along. He wanted a Watt engine to power one of his bellows. He saw the problem and had the solution ready-made. He could bore steam-engine cylinders from solid iron just as he had naval cannons, and on a larger scale. He made a massive boring tool of ultrahard iron and, with huge iron rods and iron sleighs and chains and blocks and “searing heat and grinding din,” achieved a cylinder, four feet in diameter, which as Watt later wrote “does not err the thickness of an old shilling at any part.” > By “an old shilling” he meant a tenth of an inch, which is a reminder that measurement itself—the science and the terminology—was in its infancy. An engineer today would say a tolerance of 0.1 inches. * https://www.nybooks.com/articles/2018/10/25/precision-accuracy-perfectionism/ https://www.nybooks.com/articles/2018/10/25/precision-accura... * http://www.simonwinchester.com/precision-praise http://www.simonwinchester.com/precision-praise * https://www.goodreads.com/book/show/35068671-the-perfectionists https://www.goodreads.com/book/show/35068671-the-perfectioni...
- cfmcdonald 5y ago
  I did read Winchester's chapter. I actually found Gavin Weightman's coverage of Wilkinson in The Industrial Revolutionaries better. I wanted to have more on Wilkinson, but I had to draw the line somewhere. This was already the longest post I've ever written by a good margin.

11 points by cfmcdonald 5y ago

It's amazing how long it took to get even the basics of thermodynamics figured out. You'd think some clockmaker would have made a little brass steam engine by 1600 or so. But no. Making a big engine with the necessary precision is hard, but a little demo-sized one was within the limits of 17th century clockmaking skill.

throw0101a 5y ago

I understand that the article's focus is Watt, but this throwaway line is bit disappointing: > Wilkinson’s cylinders, true to a circle with a variation of less than width of a shilling — about 1/10th of an inch — were sufficiently precise that Watt’s pistons could work without leaking a noticeable amount of steam. As much as Watt's engines were an improvement over Newcomen's in efficiency, I wouldn't be surprised if the 'Wilkinson-manufactured' engines were as much again a relative improvement by the same amount over the 'pre-Wilkinson' engines of Watt. * https://en.wikipedia.org/wiki/John_Wilkinson_(industrialist) https://en.wikipedia.org/wiki/John_Wilkinson_(industrialist) There's an entire chapter on the subject in the book The Perfectionists: How Precision Engineers Created the Modern World by Simon Winchester. From a review of the book by James Gleick: > Watt, meanwhile, had patented his steam engine, a giant machine, tall as a house, at its heart a four-foot-wide cylinder in which blasts of steam forced a piston up and down. His first engines were hugely powerful and yet frustratingly inefficient. They leaked. Steam gushed everywhere. Winchester, a master of detail, lists the ways the inventor tried to plug the gaps between cylinder and piston: rubber, linseed oil-soaked leather, paste of soaked paper and flour, corkboard shims, and half-dried horse dung—until finally John Wilkinson came along. He wanted a Watt engine to power one of his bellows. He saw the problem and had the solution ready-made. He could bore steam-engine cylinders from solid iron just as he had naval cannons, and on a larger scale. He made a massive boring tool of ultrahard iron and, with huge iron rods and iron sleighs and chains and blocks and “searing heat and grinding din,” achieved a cylinder, four feet in diameter, which as Watt later wrote “does not err the thickness of an old shilling at any part.” > By “an old shilling” he meant a tenth of an inch, which is a reminder that measurement itself—the science and the terminology—was in its infancy. An engineer today would say a tolerance of 0.1 inches. * https://www.nybooks.com/articles/2018/10/25/precision-accuracy-perfectionism/ https://www.nybooks.com/articles/2018/10/25/precision-accura... * http://www.simonwinchester.com/precision-praise http://www.simonwinchester.com/precision-praise * https://www.goodreads.com/book/show/35068671-the-perfectionists https://www.goodreads.com/book/show/35068671-the-perfectioni...

cfmcdonald 5y ago
I did read Winchester's chapter. I actually found Gavin Weightman's coverage of Wilkinson in The Industrial Revolutionaries better. I wanted to have more on Wilkinson, but I had to draw the line somewhere. This was already the longest post I've ever written by a good margin.