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 very 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 well as at mathematics.
When James was foourteen 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
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)
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 wworked 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
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 that James could not find anyone in Glasgow
able to teach him. So he set off on ho
[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 and 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 wa
steam engine that was used for demonstration at engineering lectures at the
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-
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
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 once 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 w
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 debt.
[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 there; 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
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 those 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
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, more and more orders from other parts of the country began to
come. One order was from France for an engine for supplying Paris with
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 at 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
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 and 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
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
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.