James Watt

James Watt

James Watt was born on January 19, 1736, at Greenock in Scotland, where

his father was a shipwright. Jamie, as his parents called him, was not at

all strong. He suffered from terrible headaches and this was naturally a

great handicap to him both in play and later in work.

He could not start his schooling at as young an age as most children did,

so his mother taught him to read, and his father taught him writing and

arithmetic. He had a vvery good memory and a natural love of work.

He liked mathematics and was also fond of designing and making things. For

hours he would dismantle his toys and then rebuild them to his own design

with the help of a small set of carpentry tools given to him by father.

When James was able to go to school he was sent to a private school; and

he also received private lessons. He learnt a lot of subjects, and became

good at languages as wwell as at mathematics.

When James was fourteen he was given the famous book by Isaac Newton

called Elements of Natural Philosophy. He found the book so interesting

that he read it many times and spent much time thinking about it. He then

started spending his free time on experiments. He made a small electrical

apparatus with which ha gave his friends shocks that made them jump. At the

same time he studied how steam could be condensed. Thought only fifteen, he

was already beginning to acquire knowledge that was very important for him

later when he began to design the steam engine. Soon after reading Newton’s

book on natural philosophy, James began to read books on other scientific

subjects – chemistry, medicine and anatomy.

[pic] James Watt (1736 – 1819)

An instrument-maker

James Watt, as a boy, spent much time in his father’s workshops. He learnt

about elementary mechanics and about fitting out ships.

His father always kept a good stock of telescopes, quadrants, and other

optical instruments. James showed an especial interest in these

instruments. He spent hours dismantling them to study how they worked and

then carefully reconstructed them. This led him to take an interest in

astronomy. Sometimes he went to a nearby hill and studied the stars through

ships telescopes.

When James was eighteen he decided to become a professional instrument-

maker, and in June 1754 he went to live with his uncle and aunt in Glasgow

hoping to perfect the trade there. But there were so few qualified

instrument-makers in those days tthat James could not find anyone in Glasgow

able to teach him. So he set off on horseback for London.

[pic] The new Wath’s engine

After some time James managed to persuade an instrument-manager to give

him a year’s instruction for twenty guineas. He found his training very

hard and tiring. He worked from early morning till late in the evening.

In a few months, however, he could make many things and towards the end of

his training he told his father, “I thing I shall be able to get my bread

anywhere, as I am now able to work as well as most journeymen, though I am

not so quick as many.”

Watt bought a few tools and returned to Glasgow to establish himself as

instrument-makes in that town.

At Glasgow University

It happened that Glasgow University had just received valuable instruments

for equipping a new observatory. These instruments needed cleaning and

putting into good working order, and Watt was given that job. His work on

the instruments was so good that he was allowed to call himself

“mathematical instrument-maker to the University”.

When he was twenty-one Watt was asked by a professor of medicine to make

instruments that the latter needed for his medical experiments. Then he

began to make quadrants aand sell them at a much lower price than that asked

by most instrument-makers. He also made musical instruments – organs,

violins, flutes, and guitars.

Once Watt was asked to repair a small working model of an atmospheric-

steam engine that was used for demonstration at engineering lectures at the

university.

The original full-size engine which this model represented had been built

in 1702 by the famous engineer Thomas Newcomen to pump water out of coal-

mines.

Newcomen’s engine was the first practical attempt at designing a steam-

engine, or fire-engine, as it was then steam-engine of today.

Watt soon started to think out ways to improve its efficiency. He made a

few scientific experiments in the hope of discovering the causes of its

faults.

The results of these experiments showed him that Newcomen’s engine, like

the other atmospheric-steam engines of that time, was founded on the wrong

principle. He understood that in order to make the best use of steam, it

was necessary – first, that the cylinder should be always as hot as the

steam was condensed, the water to which it was reduced and the injection

water itself should be cooled down to 100 degrees.

It took Watt two years to find a away of putting his new theory into

practice; but oonce Sunday afternoon in April 1765, while he was out for a

walk, he suddenly found the answer to his problem. It occurred to him, he

wrote later, that if communication were opened between a cylinder with

steam and another vessel which was without air or fluids, the steam, as a

fluid, would go into the empty vessel, and that if that vessel were kept

very cool by an injection or some other way, more steam would continue to

enter till the whole was condensed.

Watt had made a great discovery: the using of a separate condenser in a

engine for condensing the steam into water, so that the temperature of the

cylinder was not lowered at each stroke of the piston.

When he returned home, he took an old syringe and a few other things,

including one of his wife’s thimbles and made a model engine to test his

ideas. He introduced another new idea into his model in addition to the

separate condenser: he did not leave the top of his cylinder open and he

did not rely upon atmospheric pressure. So the cycle was completed and the

piston was operated by steam only.

Though he had managed to make a successful model without much difficulty,

he found it very difficult to

construct a full-size engine based on his

principles. He could not make his piston slide smoothly up and down the

inside of the cylinder. The steam percolated between the piston and the

cylinder and reduces power. Eventually, Watt managed to solve this problem

to a certain extent: he put a mixture of pasteboard, cork, tow and horse-

dung over the inside surface of the cylinder; but it was several years

before he thought of this, and by that time his costly experiments had run

him heavily into ddebt.

[pic] James Watt’s Boulder

At a Factory in Birmingham

Once, when Watt was on his way back from London to Scotland, he visited a

large factory in Birmingham which had been built a few years before. This

factory, described as „the largest in England“, had over workmen, who made

„all sorts of works . even astronomical clocks“.

Watt was much impressed with the factory, but ha saw one serious weakness.

The mechanical equipment used in the factory, such as it was, was driven by

a water-wheel, in much the same way as the country flour mills were driven.

But the stream providing the water ran so low in dry weather that

production was often brought to a standstill. Watt thought that his new

steam-engine could be used tthere; and in May 1774 Watt and his two children

(his wife had died three years before) want to Birmingham.

James Watt was now thirty-eight. It was eleven years since he had first

become interested in building a steam-engine, but he had still not

perfected his engine and ha had not been able to make use of it at all for

industrial purposes.

One reason why his engine was not fully efficient was that the cylinder

bore was not a perfect circle; it was a little oval. This meant that

nothing could entirely prevent the escape of steam round the piston. When

Watt explained this difficulty to his partner, the latter immediately

arranged to have better cylinders especially bored for him.

New cylinders were a great improvement on tthose that Watt had used before,

and with their help he could build an engine that at last really was

efficient. „The fire engine that I have invented is now going, and answers

its purpose better than any other that has yet been made,“ he wrote to his

father.

His engine was soon drawing up water from the mines from a lower level

than had ever been reached before.

[pic] The machines-tool

Once it was known how successfully the engine was working in the Cornish

tin-mines, mmore and more orders from other parts of the country began to

come. One order was from France for an engine for supplying Paris with

water.

Other Inventions

Watt did not work on his engine only. He made several other inventions of

a different kind. The most important of them was a copying machine to help

him with his correspondence and other written work.

This is how the machine worked. A letter or manuscript was written in a

special ink. Then thin sheets of paper were pressed in turns over the

original script until ink had successfully penetrated the paper and had

left a clear impression of the writing. Several copies could be taken very

quickly in this way, thus saving the writer hours of work.

Watt’s copying machine was used all over the country for about 100 years –

until the typewriter was invented.

He also invented a method of bleaching, a machine for drying linen, and an

instrument for determining the specific gravities of liquids.

In October 1781 Watt made a still better engine that could do much more

than merely pump water out of mines. This was a rotative engine. It could

run machines, a thing no steam-engine had ever been able to do before. This

was a great invention aat that time. Watt took some time to improve his new

relative engine. After he perfected it all kinds of industries began to use

it. In fact, it became the basis of industry: the motive power that drove

the wheels of the various machines used in industry. It could do many

things.

But there was one thing that Watt’s engine could not do: propel itself and

so drive a train. Watt thought to try to design a locomotive as well as his

stationary engine, but he soon gave up the idea of designing a locomotive.

In 1800, when James Watt was sixty-four, he retired. But he was by no

means idle in the retirement. He fitted up a room in his house as a

workshop, and shut himself away in his room for hours making experiments or

designing something. One invention that occupied his attention was a

machine for copying sculptures.

When he came out of his workshop, he usually liked to read by the fire, to

improve his general knowledge. He read anything that he could lay hands on,

but he was particularly interested in reading about music, medicine, law,

and architecture, and, of course, about engineering and scientific

subjects. He often continued his reading till late at night.

As well as reading aand experimenting, Watt received many visitors to his

own home. He was an excellent conversationalist, and people paid great

attention to everything that he said.

[pic] Watt’s statue

Recognition

James Watt lived to the age of eighty-three. He received many honors in

recognition of his valuable work. He was elected a Fellow of the Royal

Society of both London and Edinburgh. Glasgow University, the university

where he began his successful work, conferred on him the honorary degree of

Doctor of Law; and France made him a member of her famous Academy of

Sciences.

He liked very much to explain engineering problems to anyone, particularly

young people, who wished to consult him, and he was consulted very often by

people of all ages.

On August 19, 1819 James Watt died at his home. A few years later a

monument was erected to his memory in Westminster Abbey.