with a tremendous explosion, and the two passengers
clinging to the rest of the gear, falling through a height said to be
near a hundred feet. Both, though only with much time and difficulty,
recovered from the shock."

In 1840, three years after the tragic adventure connected with Mr.
Cocking's parachute trial, we find Charles Green giving his views as to
the practicability of carrying out a ballooning enterprise which should
far excel all others that had hitherto been attempted. This was nothing
less than the crossing of the Atlantic from America to England. There is
no shadow of doubt that the adventurous aeronaut was wholly in earnest
in the readiness he expressed to embark on the undertaking should
adequate funds be forthcoming; and he discusses the possibilities
with singular clearness and candour. He maintains that the actual
difficulties resolve themselves into two only: first, the maintenance of
the balloon in the sky for the requisite period of time; and, secondly,
the adequate control of its direction in space. With respect to the
first difficulty, he points out the fact to which we have already
referred, namely, that it is impossible to avoid the fluctuations of
level in a balloon's course, "by which it constantly becomes alternately
subjected to escape of gas by expansion, and consequent loss of ballast,
to furnish an equivalent diminution of weight." Taking his own balloon
of 80,000 cubic feet by way of example, he shows that this, fully
inflated on the earth, would lose 8,000 cubic feet of gas by expansion
in ascending only 3,000 feet. Moreover, the approach of night or passage
through cloud or falling rain would occasion chilling of the gas or
accumulation of moisture on the silk, in either case necessitating the
loss of ballast, the store of which is always the true measure of the
balloon's life.

To combat the above difficulty Green sanguinely relies on his favourite
device of a trail or guide rope, whose function, being that of relieving
the balloon of a material weight as it approaches the earth, could, he
supposed, be made to act yet more efficiently when over the sea in the
following manner. Its length, suspended from the ring, being not less
than 2,000 feet, it should have attached at its lower end at certain
intervals a number of small, stout waterproof canvas bags, the apertures
of which should be contrived to admit water, but to oppose its return.
Between these bags were to be conical floats,