justly--avenged, existed no longer. None of those who accompanied
him had survived. The secret of the "Albatross" was buried in the
depths of the Pacific!

That Robur had a retreat, an island in the middle of that vast ocean,
where he could put into port, was only a hypothesis; and the
colleagues reserved to themselves the right of making inquiries on
the subject later on. The grand experiment which the Weldon Institute
had been preparing for so long was at last to take place. The
"Go-Ahead" was the most perfect type of what had up to then been
invented in aerostatic art--she was what an "Inflexible" or a
"Formidable" is in ships of war.

She possessed all the qualities of a good aerostat. Her dimensions
allowed of her rising to the greatest height a balloon could attain;
her impermeability enabled her to remain for an indefinite time in
the atmosphere; her solidity would defy any dilation of gas or
violence of wind or rain; her capacity gave her sufficient
ascensional force to lift with all their accessories an electric
engine that would communicate to her propellers a power superior to
anything yet obtained. The "Go-Ahead" was of elongated form, so as to
facilitate her horizontal displacement. Her car was a platform
somewhat like that of the balloon used by Krebs and Renard; and it
carried all the necessary outfit, instruments, cables, grapnels,
guide-ropes, etc., and the piles and accumulators for the mechanical
power. The car had a screw in front, and a screw and rudder behind.
But probably the work done by the machines would be very much less
than that done by the machines of the "Albatross."

The "Go-Ahead" had been taken to the clearing in Fairmount Park, to