Recent British papers and correspondents bring very pleasing accounts of
a balloon ascension, which took place in London on the 9th of October.
This adventure is the more interesting to us, from the fact that the
well-known and experienced aëronauts, Messrs. Coxwell and Glaisher, were
accompanied in their celestial excursion by several private individuals
of distinction, and among the rest by the Hon. Robert J. Walker, of this
country, whose able contributions have done so much to enhance the value
of THE CONTINENTAL. Some years ago, this gentleman had the
scientific curiosity to descend to the bottom of the sea, in a new
diving apparatus, just then invented; and recently he has been driven
through a tunnel on a railway, by the pneumatic process, which in
certain locations and conditions, will probably hereafter be substituted
for the ordinary power of the locomotive engine. He seems to be not only
ready to welcome all valuable improvements in science and mechanics, but
is ready himself to take the risks of dangerous exploration in the
pursuit of knowledge and for the promotion of progress.
But of all such adventures, that into the regions of the atmosphere is
by far the most interesting. Living immersed in this great ocean of air
and moisture which surrounds the earth, and is the theatre of all the
grand, beautiful, benignant, and often terrific phenomena of
meteorology, it is no more than a very natural curiosity which induces
us to seek by aërial exploration to understand its physical
peculiarities, and to make use of the vast resources which it will
doubtless soon afford to the genius and enterprise of the human race.
Until recently, we believe, it has been considered a settled fact, that
the atmosphere was limited to the height of about forty-five miles, that
being estimated as the limit at which the earth's attraction would be
balanced by the expansive force of the particles of air. But in this
problem there is an element of complication in the rotation of the
atmosphere with the earth on its axis. Near the surface, and for a great
distance upward, the air is but a part of the solid globe, or rather an
appendage to it, moving with it in all respects like the denser fluid
which constitutes the mighty ocean. But there must be a point in the
ascent upward, where the centrifugal force of the particles of air, in
the diurnal rotation, must over-balance the power of gravitation; and
from that limit, the motions of the atmosphere must be subject to a law
of a wholly different character--partaking of the nature of planetary
revolution, rather than of axial rotation. The latest speculations as to
the height of the atmosphere, seem to have reached only this degree of
certainty, viz., that it does not extend so far as the orbit of the
moon. Otherwise, it is argued, the superior attraction of that body, in
its immediate vicinity, would aggregate a considerable quantity of the
air about it, which would tend to retard the motions of the satellite in
its orbit, and of the earth on its axis; whereas, the revolutions and
rotations of both are known to have been uniform for a period as far
back as authentic observation extends.
But these speculations, however curious and interesting, are of no
practical importance. We shall never be able to traverse the air to any
great distance above the earth's surface. Independent of mechanical
difficulties, two great impediments will forever prevent the realization
of any such ambitions aspirations. These are the increase of cold and
decrease of pressure in the upper regions of the air, and the deficiency
of oxygen in the rarefied element for the support of animal life. It is
well known that at the earth's surface, the pressure on all parts of the
body, internal and external, by the weight of the superincumbent
atmosphere, is no less than 14½ pounds to every square inch. The
structure of the human body is physiologically conformed by nature to
this pressure, and it cannot survive with any very great change of this
amount, either by increase or diminution. When one descends into the
water, the pressure is doubled at about 32 feet of depth. In ascending
in the atmosphere, the pressure is diminished much less rapidly, of
course, but quite sensibly when the altitude becomes very great.
Messrs. Coxwell and Glaisher are said to have ascended in 1862 to a
height of seven and a half miles. One of these gentlemen became entirely
insensible from cold and want of oxygen, and the other very nearly so,
being obliged to open the valve of the balloon with his teeth for want
of the use of his hands.
Nature provides a partial remedy for the difficulty of breathing in the
upper regions of the atmosphere. In the effort to breathe, the lungs are
found to expand and to develop air cells not ordinarily used, so as to
bring a larger quantity of the rarefied air into contact with the blood.
It has been proposed to assist this effort of nature, and, in order to
enable the aëronaut to reach a greater altitude with safety, to carry up
in bags a supply of oxygen for breathing. As air is carried or forced
down into the water to enable the diver to breathe, so it may be
conveyed upward for the benefit of the aërial adventurer.
But with all possible expedients, it is not probable that man will ever
be able to get far away from the surface of the earth which is his
natural place of abode. If he can explore the lower strata immediately
adjoining his own theatre of action--the strata in which all the great
and important phenomena of meteorology take place--and if he can succeed
in traversing it at his pleasure with safety and some degree of
celerity, as we doubt not he will eventually, this great achievement
will subserve all the useful purposes possible to be derived from such
skill and knowledge.
The atmosphere will still be the vast reservoir of oxygen, nitrogen, and
carbon, from winch all living things in the air, on the earth, or in the
depths of the boundless ocean, whether animal or vegetable, draw far the
greater part of their nutriment. We can never reach the surface of this
atmospheric ocean, for that would be for us a region of inanity and
death; but there is scarcely a doubt that we shall freely use it in the
future for purposes of locomotion, at the same time that we breathe and
assimilate it as the very pabulum and substance of our mortal bodies.
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