James Watt
person · earth · Greenock and Glasgow, Scotland; then Birmingham, England
Scottish instrument maker (1736–1819), employed by the University of Glasgow, who in 1765 realised while repairing a model Newcomen engine that the fatal loss was the reheating of the cylinder on every stroke, and that condensing the steam in a separate vessel would remove it. He patented the separate condenser in 1769 and spent the next six years failing to make it pay, because no British workshop could bore a cylinder round enough to hold the vacuum until John Wilkinson's cannon-boring machine of 1774. Watt is also the source of the unit: he defined horsepower as 33,000 foot-pounds of work per minute in order to price his engines against the animals they replaced, which is a commercial definition rather than a physical one. His reputation is double-edged in the modern literature. The 1769 patent, extended by Act of Parliament to 1800, was enforced aggressively by his partnership, and Watt's conviction that high-pressure steam was lethally dangerous — not an unreasonable view given contemporary boilers — meant the firm neither developed it nor let others do so freely until the patent lapsed.
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Timeline
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Connections · 1
- Boulton and Wattmember_of
Assembled narrative · 1
Assembled from 17 blocks · 1 evidence · 7 related
- Story
- Scottish instrument maker (1736–1819), employed by the University of Glasgow, who in 1765 realised while repairing a model Newcomen engine that the fatal loss was the reheating of the cylinder on every stroke, and that condensing the steam in a separate vessel would remove it. He patented the separate condenser in 1769 and spent the next six years failing to make it pay, because no British workshop could bore a cylinder round enough to hold the vacuum until John Wilkinson's cannon-boring machine of 1774. Watt is also the source of the unit: he defined horsepower as 33,000 foot-pounds of work per minute in order to price his engines against the animals they replaced, which is a commercial definition rather than a physical one. His reputation is double-edged in the modern literature. The 1769 patent, extended by Act of Parliament to 1800, was enforced aggressively by his partnership, and Watt's conviction that high-pressure steam was lethally dangerous — not an unreasonable view given contemporary boilers — meant the firm neither developed it nor let others do so freely until the patent lapsed.
- Knowledge
- James Watt
- Boulton and Watt
- Connections
- The steam engine
- Boulton and Watt
- Watt patents the separate condenser
- Boulton and Watt form their partnership
- James Watt
- The steam engine
- Birmingham
- Boulton and Watt form their partnership
- The rotative engine turns a shaft
- Evidence
- Supports the separate-condenser priority date, the extension of the monopoly to 1800, and the Boulton and Watt licensing model. V55 verification basis: NOT consulted — legislation.gov.uk is blocked from this session. The patent number and the regnal citation of the extending Act are deliberately omitted rather than reconstructed from memory.
Observed changes · 0
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