50 Fun Facts About James Watt

In which Scottish town was James Watt born in 1736?

He was the eldest of five surviving children; his father was a shipwright and shipowner who served as the town's chief baillie.

What was the trade of Watt's father?

His grandfather Thomas taught mathematics, surveying and navigation; the family were Presbyterian Covenanters, though Watt became a deist.

Whose 1712 engine did Watt famously improve rather than invent?

The Newcomen atmospheric engine had pumped mine water for half a century with barely a change in design.

In which city did the young Watt spend a year (1755–56) training as an instrument maker?

Without a full apprenticeship he struggled to set up in Glasgow until instruments bequeathed from Jamaica gave him work at the university.

At which university did Watt run a small workshop as an instrument maker?

Three professors offered him space after he restored the Macfarlane astronomical instruments; there he met chemist Joseph Black.

What was Watt's key insight about why Newcomen engines wasted energy?

His separate condenser kept the cylinder hot, radically improving power, efficiency and running cost.

Where was Watt walking in May 1765 when he hit on the idea of the separate condenser?

He surrounded the cylinder with a steam jacket too, and had a working model later that same year.

Which chemist, famous for the concept of latent heat, helped fund Watt's early engine work?

Larger backing then came from John Roebuck, founder of the Carron Iron Works.

At which Bo'ness estate did Watt work on his engine in a cottage beside his backer John Roebuck's home?

Roebuck later went bankrupt and Matthew Boulton acquired his share of the patent.

In which year was Watt's fundamental separate-condenser patent enrolled?

Patent 913, 'a method of lessening the consumption of steam', was extended to 1800 by Act of Parliament in 1775.

With which Birmingham manufacturer did Watt form his famous partnership in 1775?

Boulton owned the Soho Manufactory and the two men later shared a Bank of England £50 note.

Which ironmaster's cannon-boring technique produced tight-fitting cylinders for Watt's engine?

He worked at Bersham near Wrexham; the Coalbrookdale cylinders had proved too leaky for Watt's airtight piston.

Where were most of the first commercial Watt engines of 1776 onwards installed?

They produced only reciprocating motion for pump rods; rotary engines for mills came later.

How did Boulton and Watt charge customers for their early engines?

The scheme failed for customers who used horses rather than old engines, which pushed Watt to invent horsepower.

Which mechanism did Watt use for rotary motion because a rival held the crank patent?

James Pickard's crank patent expired in 1794, but the firm kept using the alternative long after; William Murdoch may have devised it.

Which invention, patented in 1784, was Watt proudest of?

It gave the straight-line motion double-acting engines needed from a beam whose end moves in an arc.

What did Watt patent in 1788 to stop his engines 'running away'?

With the throttle valve and other refinements his engine became up to five times as fuel-efficient as Newcomen's.

Which Watt device, kept as a trade secret, plotted cylinder pressure against volume?

Its diagrams later became a standard tool for engineers analysing engine efficiency.

A double-acting engine, described by Watt, does what?

He also described working steam 'expansively' at pressures above atmospheric, and patented these ideas in 1781 and 1782.

How many turns per hour of a 12-foot mill wheel did Watt reckon a horse could manage when defining horsepower?

With a pull of 180 pounds-force, that works out to about 33,000 foot-pounds per minute.

Why did Watt need to invent horsepower at all?

His coal-savings royalty was meaningless to a brewer or miller whose power came from draught horses.

When did the General Conference on Weights and Measures adopt the watt into the SI system?

C. William Siemens proposed the name in 1882 and the British Association adopted it in 1889.

One watt equals one what per second?

The unit measures the rate of energy transfer, or 1 kg·m²·s⁻³.

Who proposed naming the unit of power the watt in an 1882 address to the British Association?

He was the Association's president that year.

What was Watt's patent 1,244 of 1780 for?

His copying press served offices for a century; he never patented his later machines for copying sculptures.

Which chemical process did Watt investigate after seeing Berthollet make chlorine in Paris in 1786?

He had already found that a chlorine solution bleached cloth, and pursued experiments back in Britain.

Which Birmingham intellectual circle counted Watt among its important members?

Regular attendees included Boulton, Erasmus Darwin, Josiah Wedgwood and Joseph Priestley.

In which year did Watt retire, the same year his fundamental patent and the Boulton partnership expired?

The firm passed to the two men's sons, and engineer William Murdoch was soon made a partner.

What was the name of Watt's home near Handsworth where he died in 1819?

He was 83; his garret workshop there was later moved intact to the Science Museum in London.

Where was Watt buried?

The church was later extended so his grave now lies inside the building.

Francis Chantrey's colossal statue of Watt was placed in Westminster Abbey and later moved where?

Its inscription says he 'enlarged the resources of his country, increased the power of man'.

On which Bank of England note did Boulton and Watt appear together from 2011?

It was the first dual portrait on a Bank of England note; Watt's quote reads 'I can think of nothing else but this machine'.

Which Scot had preceded Watt as the only other Scottish figure on a Bank of England note?

Smith appeared on the £20 note issued in 2007.

How much more fuel-efficient than a Newcomen engine was Watt's improved engine, at best?

That efficiency came from the separate condenser, throttle valve, governor and expansive working together.

What is the factual basis behind the legend that boiling water on the hob inspired Watt's engine?

The tale of the rattling lid inspiring the engine is probably apocryphal, but the kettle in his lab was real.

When did Boulton and Watt open their own Soho Foundry to cast engines?

Before that, cylinders and castings were made by others to Watt's drawings, with Watt acting as consulting engineer.

Which long-serving Boulton and Watt engineer, credited by some with the rotary mechanism, became a partner in 1810?

He never contested Watt's 1781 patent and retired from the firm twenty years later.

Whom did Watt marry in 1764, losing her to childbirth in 1773?

He was surveying in the Highlands when she fell ill; he remarried Ann MacGregor, a dye-maker's daughter, in 1777.

Watt's son Gregory, from his second marriage, became known in which field?

Gregory died young in 1804; James Jr. carried on the engine business.

Which Edinburgh institution began in 1821 as the world's first Mechanics Institute?

It was renamed for James Watt in 1852 and became Heriot-Watt University in 1966; George Heriot was jeweller and banker to James VI and I.

How did Watt prefer to communicate his ideas, rather than publishing in journals?

He was nonetheless a prolific correspondent, writing to Boulton several times a week from Cornwall.

Which learned body made Watt a fellow in 1784?

Rotterdam's Batavian Society followed in 1787 and the Smeatonian Society of civil engineers in 1789.

What did Watt's grandfather Thomas teach, as well as serving as baillie to the Baron of Cartsburn?

Young James was schooled at home by his mother before Greenock Grammar School, where Latin and Greek left him cold.

Raised by Presbyterian Covenanter parents, what religious position did Watt later adopt?

His father was a shipwright and Greenock's chief baillie whose wealth came partly from trading in slaves and slave-produced goods.

Which engine builder did Watt sue in 1793 in the first of his patent-infringement trials?

Hornblower's case ended decisively for Watt in 1799; friend John Wilkinson had quietly erected some 20 engines of his own.

Watt wrote in 1772 that he would rather face what than settle an account or make a bargain?

He was a poor businessman who hated negotiating and suffered from nervous headaches and depression.

In retirement Watt built an unpatented machine for copying what?

One of its first products was a small head of his old friend Adam Smith.

In 1816 Watt revisited Greenock aboard which pioneering paddle-steamer?

He also bought and improved an estate at Doldowlod House in mid-Wales.

Where has Watt's untouched garret workshop been recreated in its entirety since 1924?

Locked after his death, it was first opened in 1853 and went back on public display in 2011.

In which year did the French Academy make Watt a Foreign Associate?

Glasgow University had given him an honorary Doctor of Laws in 1806.