YOUNG STEAM ENGINEER'S GUIDE.
ARTICLE I.
OF STEAM.
OF all the principles of Nature, which man by his ingenuity has yet been able to apply as a powerful agent to aid him in the attainment of a comfortable subsistence, Steam, produced by boiling water, will perhaps soon be esteemed first in the class of the most useful for working all kinds of mills, pumps, and other machinery, great or small.
Water-falls are not at our command in all places, and are liable to be obstructed by frost, drought, and niany other accidents. Wind is inconstant and unsteady:animal power, expensive, tedious in the operation, and
unprofitable, as well as subject to innumerable accidents.
On neither of these can we rely with certainty. But steam at once presents
us with a faithful servant, at command in all places, in all seasons; whose
power is unlimited; for whom no task is too great nor yet too small; quick
as lightning in operation; docile as the elephant led by a silken thread,
ready, at our command, to rend asunder the strongest works made by the art
of man.
In our search for the means to apply this agent, we have
wandered from the true path of nature. It has long been known, that steam
confined would in all cases burst the vessel if a sufficient degree of heat
were applied, and no vent given for it to escape; and it was equally well
known, that if it had liberty to escape, no heat that we could apply would
endanger the bursting of the vessel. Was there ever a plainer case presented
to our view in all the works of nature, or an inference more easily drawn,
than that by this agent we can obtain any power we may want, by the simple
means of confining the steam and increasing the heat? or that to do this
we had only to make our boilers strong in proportion to the power we wished
to obtain. Yet philosophers have immortalized their names by wandering from
this simple path of nature, leading the world astray to stumble in the dark
for one hundred years, over the many obstacles which lay in the crooked
way; by discovenng that steam might be used as an agent to drive the air out of a vessel, and that this steam could be instantly condensed again
by a jet of cold water, and by these means form a vacuum in the vessel,
that the air under the weight of the atmosphere, being suffered to rush
into the vessel, would produce a power sufficient to work an engine. This
was certainly a great discovery, and will ever remain useful; and being
improved on, finally produced the greatest and most powerful engines ever
invented by human ingenuity.*
*Here the reader should know, that the weight of the atmosphere (which is the air surrounding the earth), has been found to be equal to 15 pounds to every superficial inch of the area of the whole surface of the earth. This air, being so heavily pressed by
3
To philosophy we are indebted for many our most useful
discoveries; yet this since case should put our philosophy to the blush,
and teach us, however learned we may be, to listen with thc closest attention,
even to what the most illiterate mechanician, who has taken the simple works
of nature for his guide, may say. He would have pointed out to us, that
it is much easier to apply the elastic power of steam simply to work the
engine in the first instance. But we have shut our ears, and continue to
use arguments to prove the application ot the simple principle impossible,
even after it is applied to engines daily in operation before our eyes.
its own weight, insinuates itself into the cavities of all bodies; and inside as well as outside of all animals which move therein. They are insensible of the pressure, because the elastic spring of the air inside their bodies is exactly equal to its weight outside, and instead of pressing them to the earth it buoys up a part of their weight, the same as any other fluid does, in proportion to its weight, when they walk in it. When we walk in water we can hardly sink to touch the bottom, because the water is of greater specific gravity than our bodies. Balloons rise in air because they are lighter than their bulk of air: our bodies would sink but little in quicksilver. If we by any means extract the air from the inside of a vessel we form what is called a vacuum, there being no air inside to balance, by its elastic spring, the weight outside of the vessel, every inch of its surface being pressed inward by a weight equal to 15 pounds. Steam, let into a cylinder in which a piston is fitted to work, drives out the air, and the steam being condensed by a jet of cold water, forms a vacuum under the piston, and the weight of the air on the upper side presses the piston to the other end of the cylinder, with a power equal to 15 pounds to the inch of its area: thus steam has been used as the best means for forming vacua to apply the weight of the air as a power to move engines.