It all began with a kettle.
James Watt's aunt was angry. Rather than
reading a good book, the fifteen-year-old
sat around the house all day just watching
the kettle boil.
He'd lift the lid, look inside, see the steam
rising, see the steam condensing against
the lid, and what the aunt saw as idleness,
was really keen attention of a junior scientist,
a man who would one day, invent the world's
first, really efficient, steam engine.
James Watt grew up to be a maker scientific instruments at Glasgow University.
One day, he was asked to repair a model of
an early steam engine, the Newcomen engine.
The model had literally run out of steam.
The Newcomen engine had been in use since
the beginning of the 18th century.
It was mainly used for pumping water out of
mines, but didn't work terribly well.
The engine operated on the principle of a
vacuum, created by condensing steam in a single cylinder.
However, it consumed a huge amount of coal
to produce not a lot of power.
This is where Watt had a simple ingenious
idea, a real leap forward, the cooling process
was separated from the cylinder.
Here we have his condenser down here, a
wonderful thing, which means that the cylinder,
upstairs, can remain hot all the time.
Steam from the boiler enters the cylinder
at the top, pushing down the piston inside.
At the end of the stroke, the pressure in the cylinder is
equalized, and the natural weight of the pump
rod pulls the piston up towards its starting
position.
As it rises, the valve releases the steam
into the bottom of the cylinder.
On each downward stroke, this steam is drawn
into the separate condenser where it is condensed.
This process creates a vacuum, which pulls down the piston as the steam above pushes it down.
It's an amazingly efficient use of steam.
It means that the Watt engine consumes less
than a third of the amount of coal used by
the Newcomen engine.
It's also twice as powerful.
The awesome power of this engine raised a
ton of water with every stroke.
That's nearly 4 million gallons a day.
But Watt's engine was to become more than
just an efficient super pump.
It was to drive the transformation of every
workplace in the country.
