were several cabins, including that of the engineer, the saloon, and
above them all a glass house in which stood the helmsman, who steered
the vessel by means of a powerful rudder. All these cabins were
lighted by port-holes filled with toughened glass, which has ten
times the resistance of ordinary glass. Beneath the hull was a system
of flexible springs to ease off the concussion when it became
advisable to land.

Engines of suspension and propulsion.--Above the deck rose
thirty-seven vertical axes, fifteen along each side, and seven, more
elevated, in the centre. The "Albatross" might be called a clipper
with thirty-seven masts. But these masts instead of sails bore each
two horizontal screws, not very large in spread or diameter, but
driven at prodigious speed. Each of these axes had its own movement
independent of the rest, and each alternate one spun round in a
different direction from the others, so as to avoid any tendency to
gyration. Hence the screws as they rose on the vertical column of air
retained their equilibrium by their horizontal resistance.
Consequently the apparatus was furnished with seventy-four suspensory
screws, whose three branches were connected by a metallic circle
which economized their motive force. In front and behind, mounted on
horizontal axes, were two propelling screws, each with four arms.
These screws were of much larger diameter than the suspensory ones,
but could be worked at quite their speed. In fact, the vessel
combined the systems of Cossus, La Landelle, and Ponton d'Amecourt, as
perfected by Robur. But it was in the choice and application of his
motive force that he could claim to be an inventor.

Machinery.--Robur had not availed himself of the vapor of water or
other liquids, nor compressed air and other mechanical motion. He