still have at
command a surplus ascensional force of upwards of ninety millions of
pounds; a force sufficient to sustain a body of fifty thousand men!

'In the construction of these enormous balloons, M. Petin proposes to
substitute, in place of the silken bag hitherto used to contain the
gas, a rigid envelope of a cylindro-conical form, composed of a series
of metallic tubes, laid one above the other, and supplied with
gas--obtainable to any amount and almost instantaneously--from the
decomposition of water by a powerful electric battery; and with these
resources at command, M. Petin conceives that balloons might be
constructed on a scale even larger than that just given!

'In fact, this assumption of the possibility of obtaining command of
an unlimited ascensional force has suggested, to certain enthusiastic
partisans of M. Petin's theory and plans, a long perspective of
astounding visions, from which sober-minded Englishmen would, in all
probability, turn away with derision. These enthusiasts have evidently
adopted the language of Archimedes, and are ready to exclaim: "Give us
a _fulcrum_, and," with hydrogen gas as our lever, "we will move the
world!"

'For ourselves, we have already stated the facts from which we derive
our conviction that the conquest of the air, if achieved, is to be
brought about through the agency of new and powerful mechanical
combinations, rather than by means of the balloon; and though, as
before remarked, the experiments of M. Petin and others may probably
not be without useful results, we dismiss these brilliant
phantasmagoria with the charitable reflection, that the extravagance
of overweening hopefulness is, at least in an age which has witnessed
the advent of steam and electricity, more natural and more pardonable
than the scepticism of confirmed despondency; and that "he who shoots
at the stars," though missing his aim, will at all events shoot higher
than he who aims at the mud beneath his feet.

'Meantime, the science of meteorology--a subject intimately connected
with that of aero-locomotion--though yet in its infancy, already
furnishes many indications of great importance, as establishing a very
strong presumption in favour of the existence of permanent atmospheric
currents, blowing continuously in various directions at different
degrees of elevation.

'We know that air, when rarefied by heat, becomes lighter and rises,
cold air immediately rushing in to supply its place; and