single ton will darken all eastern
North America for five days. Whereas the concentration would be made
only in specific areas liable to attack. The gas is distilled with
great facility from one of the tri-phenyl-carbinol coal-tar
derivatives."

Vice-president Tomlinson was a pompous, irascible old man, but it was
he who hit the nail on the head.

"That's all very well as an emergency measure, but we've got to find
the haunt of that gang and smash it!"

An orderly brought in a telegraphic dispatch and handed it to him. The
Vice-president opened it, glanced through it, and tried to hand it to
the Secretary of State. Instead, it fluttered from his nerveless
fingers, and he sank back with a groan. The Secretary picked it up and
glanced at it.

"Gentlemen," he said, trying to control his voice, "New York was
bombed out of the blue at sunrise this morning, and the whole lower
part of the city is a heap of ruins."

* * * * *

In the days that followed it became clear that all the resources of
America would be needed to cope with the Invisible Empire. Not a day
passed without some blow being struck. Boston, Charleston, Baltimore,
Pittsburg in turn were devastated. Three cruisers and a score of minor
craft were sunk in the harbor of Newport News, where they were
concentrating, and thenceforward the fleet became a fugitive force,
seeking concealment rather than an offensive. Trans-Atlantic
sea-traffic ceased.

Meanwhile the black gas was being hurriedly manufactured. From
cylinders placed in central positions in a score of cities it was
discharged continuously, covering these centers with an impenetrable
pall of night that no light would penetrate. Only by the glow of
radium paint, which commanded fabulous prices, could official business
be transacted, and that only to a very small degree.

Courts were closed, business suspended, prisoners released, perforce,
from jails. Famine ruled. The remedy was proving worse than the
disease. Within a week the use of the dark gas had had to be
discontinued. And a temporary suspension of the raids served only to
accentuate the general terror.

There were food riots everywhere, demands that the Government come to
terms, and counter-demands that the war be fought out to the bitter
end.

Fought out, when everything was disorganized? Stocks of food congested
all the terminals, mobs rioted and battled and plundered all through
the east.

"It means s