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 aerial 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. Ind