mption of fuel was
enormous in Savory's engine, as may easily be perceived from the great
loss of steam by condensation. Nevertheless, it was on the whole a good
and a workable engine, as we find the following said of it by Mr.
Farey:--"When comparison is made between Captain Savory's engine and
those of his predecessors, the result will be favourable to him as an
inventor and practical engineer. All the details of his invention are
made out in a masterly style, so as to make it a real workable engine.
His predecessors, the Marquis of Worcester, Sir S. Morland, Papin, and
others, only produced outlines which required to be filled up to make
them workable."

I must not detain you much longer before I proceed to the great Watt,
but I will just name Newcomen, who invented an engine with a cylinder,
and introduced a beam, to the other end of which he fixed a pump rod
like a common or garden pump. He made the weight of the pump and beam to
lift the piston, and then let the steam enter below the piston and
condensed it by a jet of water, thus causing a vacuum, when the pressure
of the atmosphere drove the piston from the top to the bottom of the
cylinder and lifted the pump rods in the usual way. There were various
cocks to be opened and shut in the working of this engine for the right
admission of steam and water at the required moments, a task which was
performed by boys who were termed cock-boys. I will now mention an
instance which, though in practice not to be imitated, yet was one of
those happy accidents which sometimes turn out for the best. One of
these boys, like many, more fond of play than work, got tired of turning
these cocks day by day, and conceived the idea of making the engine do
it for itself. This idle boy--we will not call him good-for-nothing, as
he proved good for a great deal in one way--was named Humphrey Potter,
and one day he fixed strings to the beam, which opened and shut the
valves, and so allowed him to play, little thinking this was one of the
greatest boons he could possibly have bestowed on the world at large,
for by so doing he rendered the steam-engine a self-acting machine.

We now come to a period which was destined to advance the cause of steam
to a far greater extent--in fact, the time which rendered the
steam-engine the useful and valuable machine it now is. This is the time
of James Watt. This great man, be it said to the credit of Scotland, was
born in Greenock, on the Clyde, on the