on of Einstein's gravitation and
electricity in field relation. It is by means of this, and the three
dynamos on the ground that we were able to neutralize your engines
last night and bring them down where we wanted them. You must be sure
to tell the Washington hogs about that."

* * * * *

He motioned to Dick to cross the room and ascend the spiral staircase.
Following him, he flung another switch similar to the first one, and
instantly all sound within the room was cut off.

They ascended the winding flight and emerged upon a floor or platform.
Dick felt it under his feet, but he could see nothing except the
ground, far beneath him. He seemed to be suspended in the void. He
stopped, groping, hesitating to advance. Von Kettler's jarring laugh
grated on his ears.

"Don't be afraid, swine," he jeered. "This place is enclosed. There is
a shadow-breaking device on every floor, which renders us complete
masters of camouflage."

A switch snapped. Dick found himself instantly in a rotunda, roofed
with glass, sections of which were raised to a height of three or four
feet from the wooden base, admitting a gentle breeze. Three or four
men were moving about in it, but these wore the black uniform with the
silver braid, and Von Kettler's manner was deferential as he addressed
them, jerking his hand contemptuously toward Dick. Grins of derision
and malice appeared on all the faces.

Save one, an elderly officer, apparently of high rank, who came
forward and raised his hand to the salute.

"Captain Rennell," he said, "we are at war with your nation, but we
are also, I hope, gentlemen." He turned to Von Kettler. "Is it
seemly," he asked, "that an officer of the American army should be
brought here in chains and cords?"

"Excellency, it is His Majesty's command," responded Von Kettler, with
a servile smirk that hardly concealed his elation. "Moreover, the
American is to witness the forthcoming destruction of the Yankee
fleet."

The elderly officer reddened, turned away without replying. Dick
looked about him.

* * * * *

There was less machinery in this room. The iron pillar that he had
seen came through the floor and terminated some five feet above it in
another of the opaque glass domes, filled with iridescent fire. About
it was a complicated arrangement of dials and gauges.

In the centre of the room was a sort of camera obscura. A large hood
projected