ottish boy, James Watt, sat on the
hearth in his mother's cottage, intently watching the steam 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 of capital and of
enterprise, owner of the Soho Engineering Works, near Birmingham. The
firm of Boulton and Watt became famous, and James Watt lived till August
19, 1819--lived to see his steam engine the greatest single factor in
the new industrial era that had dawned for English-speaking folk.

Boulton and Watt, however, though they were the pioneers, were by no
means alone in the development of the steam engine. Soon there were
rivals in the field with new types of engines. One of these was Richard
Trevithick in England; another was Oliver Evans of Philadelphia. Both
Trevithick and Evans invented the high-pressure engine. Evans a