deserts inaccessible by other means of travel, and visiting
places which travellers have never penetrated, would be of immense use
in the science of geography: and when under the line, if the heat near
the earth should be inconvenient, the aeronauts would, of course, easily
rise to elevations where the temperature is equal and agreeable. When
their observations, their needs, or their pleasures demanded it, they
could descend to within a short distance of the earth, say ninety feet,
and fix themselves in their position by means of an anchor. It might,
perhaps, be possible, by taking the advantage of favourable winds, to
make the tour of the world. "Experience will perhaps demonstrate that
aerial navigation presents less inconvenience and less dangers than the
navigation of the seas."

The immensity of the seas seemed to be the only source of insurmountable
difficulties; "but," says Robertson, "over what a vast space might
not one travel in six months with a balloon fully furnished with the
necessaries of life, and all the appliances necessary for safety?
Besides, if, through the natural imperfection attaching to all the works
of man, or either through accident or age, the balloon, borne above the
sea, became incapable of sustaining the travellers, it is provided with
a boat, which can withstand the waters and guarantee the return of the
voyagers."

Such were the ideas promulgated regarding the "Minerva." The following
is the serious description given of the machine. The numbers correspond
with those on the illustration.

"The cock (3) is the symbol of watchfulness; it is also the highest
point of the balloon. An observer, getting up through the interior to
the point at which the watchful fowl is placed, will be able to command
the best view to be had in the 'Minerva.' The wings at the side (1 and
2) are to be regarded as ornamental. The balloon will be 150 feet in
diameter, made expressly at Lyons of unbleached silk, coated within and
without with indict-rubber. This globe sustains a ship, which contains
or has attached to it all the things necessary for the convenience, the
observations, and even the pleasures of the voyagers.

"(a) A small boat, in which the passengers might take refuge in case
of necessity, in the event of the larger vessel falling on the sea in a
disabled state.

"(b) A large store for keeping the water, wine, and all the provisions
of the expedition.

"(cc) Ladders of silk, to enable the pass