rising from the mouth of the tea kettle, and of the great role
which this boy afterwards assumed in the mechanical world. It was
in 1763, when he was twenty-eight and had the appointment of
mathematical-instrument maker to the University of Glasgow, that
a model of Newcomen's steam pumping engine was brought into his
shop for repairs. One can perhaps imagine the feelings with which
James Watt, interested from his youth in mechanical and
scientific instruments, particularly those which dealt with
steam, regarded this Newcomen engine. Now his interest was
vastly. quickened. He set up the model and operated it, noticed
how the alternate heating and cooling of its cylinder wasted
power, and concluded, after some weeks of experiment, that, in
order to make the engine practicable, the cylinder must be kept
hot, "always as hot as the steam which entered it." Yet in order
to condense the steam there must be a cooling of the vessel. The
problem was to reconcile these two conditions.

At length the pregnant idea occurred to him--the idea of the
separate condenser. It came to him on a Sunday afternoon in 1765,
as he walked across Glasgow Green. If the steam were condensed in
a vessel separate from the cylinder, it would be quite possible
to keep the condensing vessel cool and the cylinder hot at the
same time. Next morning Watt began to put his scheme to the test
and found it practicable. He developed other ideas and applied
them. So at last was born a steam engine that would work and
multiply man's energies a thousandfold.

After one or two disastrous business experiences, such as fall to
the lot of many great inventors, perhaps to test their
perseverance, Watt associated himself with Matthew Boulton, a man