enclosure.

Without, blows on metal sharply resounded. The Master smiled again, as
he realized his orders were going on with exact precision.

"That's the wireless they're putting out of commission," thought he,
glancing at his watch again. "No mere untuning of wave-lengths.
Good, old-fashioned hammer-blows! This station won't work again for a
while!"

Bohannan, meantime, was trying to get some general impression of the
giant plane. Not all the Master's descriptions of it, to him, had
quite prepared him for the reality. Though he well knew all the
largest, biggest machines in the world, this stupendous creation
staggered him. By comparison with the Handley-Page, the Caproni, the
D.H.-4, the Gotha 90-120, the Sikorsky, it spread itself as an eagle
spreads beside a pigeon.

It lay in a kind of metallic cradle, almost like a ship ready for
launching on its ways. Ahead of it, metal plates stretched away like
rails, running toward the lip of the Palisades. Its quadruple floats,
each the size of a tugboat and each capable of being exhausted of air,
constituted a potential lifting-force of enclosed vacuums that
very largely offset the weight of the mechanism. It was still a
heavier-than-air machine, but the balance could be made nearly
perfect. And the six helicopters, whose cylindrical, turbine-like
drums gleamed with metallic glitters--three on each side along the
fuselage--could at will produce an absolutely static condition of lift
or even make the plane hover and soar quite vertically.