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 ...