the resistance of the air, without occasioning any loss of containing
power), would suffice to raise one hundred millions of pounds; and
allowing some four or five millions of pounds for the weight of the
vessel and its machinery, which, for a ship of this size--supposing it
were possible to make its various parts hold together--should be, M.
Pétin computes, of twelve hundred horse-power, we should 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. Pétin 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. Pétin 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. Pétin'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