is in which it is involved is founded upon a presumed
analogy with a Balloon exposed to the action of the wind while in a
state of attachment to the earth, I would first observe that the cases
in question, however apparently analogous, are in reality essentially
dissimilar. In the one case (that where the Balloon is supposed to be
attached to the earth) all the _motion_, and consequently all the
_momentum_, is in the air; in the other case (where the Balloon
is supposed to be progressive), it is in the constituent particles of
the machine itself and of its gaseous contents. And this momentum,
which is ever proportioned to the rate of its motion, and,
consequently, to the amount of resistance it experiences, is amply
sufficient to secure the preservation of the form of its opposing
front, however partially distended, and whatever the velocity with
which it might happen to be endowed. Independently, however, of this
corrective principle, another, equally efficacious is afforded in the
buoyant power of the included gas, which, occupying all the upper part
of the Balloon so long as it is in a condition to sustain itself in
the air, and generally extending to its whole capacity, presses from
within with a force far greater than any it could experience from
the external impact of the atmosphere, and sufficiently resists any
impression from that quarter which might tend to impair its form.
To what extent this is effective, will appear more clearly when we
observe that in any balloon inflated, it is the _sides_ of the
distended globe that bear out the weight of the appended cargo,
through the intervention of the network; a weight only limited by the
sustaining power of the machine itself, and in the case of the great
Vauxhall or Nassau Balloon, amounting to more than two tons, and
consequently pressing with a force far exceeding any that could arise
from the impact of the air at any rate of motion it could ever be
expected to accomplish. And this statement, which represents the
theoretical view of the question, is fully borne out by the real
circumstances of the case as they appear in practice. So far
from justifying the apprehensions of those who conceive that the
_front_ of the Balloon would be disfigured by its compulsory
progression through the air, the result is exactly the reverse; the
only tendency to derangement of form displaying itself in the part
_behind_, where the rushing in of the atmospheric medium to fill
the pl