to your tubes!" came Samms' ringing
voice.

As the words were being spoken, mighty blasts of power raved from the
driving projectors and the immense mass of the super-ship shot out
through the portals and upward into the stratosphere. Through the
tenuous atmosphere the huge ship rushed with ever-mounting speed, and
while the hope of Triplanetary drove eastward Rodebush studied the
ever-changing scene of battle upon his plate and issued detailed
instructions to the highly trained specialists manning every offensive
and defensive weapon.

But the Nevians did not wait to join battle until the newcomers arrived.
Their detectors were sensitive--operative over untold thousands of
miles--and the ultra-screen of the Hill had already been noted by the
invaders as the earth's only possible source of trouble. Thus the
departure of the _Boise_ had not gone unnoticed, and the fact, that, not
even with his most penetrant rays could he see into her interior, had
already given the Nevian commander some slight concern. Therefore, as
soon as it was determined that the great ship was being directed toward
Pittsburgh the fish-shaped cruiser of the void went into action.

High in the stratosphere, speeding eastward, the immense mass of the
_Boise_ slowed abruptly, although no projector had slackened its effort.
Cleveland, eyes upon interferometer grating and spectrophotometer
charts, fingers flying over calculator keys, grinned as he turned toward
Rodebush.

"Just as you thought, Skipper; an ultra-band pusher. C4V63L29. Shall I
give him a little pull?"

"Not yet; let's feel him out a little before we force a close-up. We've
got plenty of mass. See what he does when I put full push on the
projectors."

As the full power of the Terrestrial vessel was applied the Nevian was
forced backward, away from the threatened city, against the full drive
of her every projector. Soon, however, the advance was again checked,
and both scientists read the reason upon their plates. The enemy had put
down re-enforcing rods of tremendous power. Three compression members
spread out fanwise behind her, bracing her against the low mountainside,
while one huge tractor beam was thrust directly downward, holding in an
unbreakable grip a cylinder of earth extending deep down into bedrock.

"Two can play at that game!" And Rodebush drove down similar beams, and
forward-reaching tractors as well. "Strap yourselves in solid,
everybody!" he sounded a general war