Steam Steel and Electricity | Page 3

that once lay hundreds of
miles away has made the delta of every river that flows into the sea.
The endless and resistless process goes on without ceasing, a force that
is never expended, and but once interrupted within the knowledge of
men, then covered a large area of the world with a sea of ice that buried
for ages every living thing.
The common idea of the steam that we make by boiling water is that it
is all water, composed of that and nothing else, and this conception is
gathered from apparent fact. Yet it is not entirely true. Steam is an
invisible vapor in every boiler, and does not become what we know by
sight as steam until it has become partly cooled. As actual steam
uncooled, it is a gas, obeying all the laws of the permanent gases. The
creature of temperature and pressure, it changes from this gaseous form
when their conditions are removed, and in the change becomes visible
to us. Its elasticity, its power of yielding to compression, are enormous,
and it gives back this elasticity of compression with almost
inconceivable readiness and swiftness. To the eye, in watching the
gliding and noiseless movements of one of the great modern engines,
the power of which one has only a vague and inadequate conception
seems not only inexplicable, but gentle. The ponderous iron pieces
seem to weigh nothing. There is a feeling that one might hinder the
movement as he would that of a watch. There is an inability to realize
the fact that one of the mightiest forces of nature is there embodied in
an easy, gliding, noiseless impulse. Yet it is one that would push aside
massy tons of dead weight, that would almost unimpeded crush a hole
through the enclosing wall, that whirls upon the rails the drivers of a
locomotive weighing sixty tons as though there were no weight above
them, no bite upon the rails. There is an enormous concentration of
force somewhere; of a force which perhaps no man can fairly estimate;

and it is under the thin shell we call a boiler. Were it not elastic it could
not be so imprisoned, and when it rebels, when this thin shell is torn
like paper, there is a havoc by which we may at last inadequately
measure the power of steam.
We have in modern times applied the word "engine" almost exclusively
to the machine which is moved by the pressure of steam. Yet we might
go further, since one of the first examples of a pressure engine, older
than the steam machine by nearly four hundred years, is the gun.
Reduced to its principle this is an engine whose operation depends
upon the expansion of gas in a cylinder, the piston being a projectile.
The same principle applies in all the machines we know as "engines."
An air-engine works through the expansion of air in a cylinder by heat.
A gas-engine, now of common use, by the expansion, which is
explosion, caused by burning a mixture of coal-gas and air, and the
steam-engine, the universal power generator of modern life, works by
the expansion of the vapor of water as it is generated by heat. Steam
may be considered a species of gradual explosion applied to the uses of
industry. It often becomes a real one, complying with all the conditions,
and as destructive as dynamite.
It cannot be certainly known how long men have experimented with the
expansive force of steam. The first feeble attempt to purloin the power
of the geyser was probably by Hero, of Alexandria, about a hundred
and thirty years before Christ. His machine was also the first known
illustration of what is now called the "turbine" principle; the principle
of reaction in mechanics. [Footnote: This principle is often a puzzle to
students. There is an old story of the man who put a bellows in his boat
to make wind against the sail, and the wind did not affect the sail, but
the boat went backward in an opposite direction from the nozzle of the
bellows. There is probably no better illustration of reaction than the
"kick" of a gun, which most persons know about. The recoil of a
six-pound field piece is usually from six to twelve feet. It can be
understood by supposing a gun to be loaded with powder and an iron
rod longer than the barrel to be left on the charge. If the outer end of
this rod were then placed against a tree, and the gun were fired, it is
manifest that the gun would become the projectile, and be fired off of

the rod backward or burst. In ordinary cases the air in the bore, and
immediately outside of the muzzle, acts comparatively, and in a