alley?" The
Atlantean's blunt outstretched finger indicated a towering pine
sprouting from among a mass of reddish volcanic rock at the rim of
that new world.

"Yes, I see it, but--" Nelson was astounded. A pine tree in the upper
Arctic! That alone was sufficient cause for amazement. From a stiff
red-plumed gun captain issued a brief series of commands which set the
wonderfully drilled crew to silently adjusting their training and
elevating mechanism. Click! Clack! Sis-s-s-s!

* * * * *

All up and down the vast staircase other gun crews stood watching.
Nelson saw their weird, bluish goggles raised to that platform where,
for all the world like a coast defense howitzer, the great cannon
swung majestically about on the ponderous, brazen column which seemed
to support it. Gradually the muzzle was elevated, then traversed a few
feet, to finally come to a halt.

"Jakul, a Hero!" shouted the gun captain, his hand raised to Hero
Giles.

"Thou art ready, Friend Nelson?" he inquired in tolerant amusement.
"Mark well yon pine tree!

"Storr!"

Nelson saw one of the armored cannoneers bend forward, firmly grasp a
short lever with both hands. In anticipation of a terrific report, the
aviator pressed finger tips to his ears. There followed not a
thundering crash, but a curious, eery, high-pitched scream, rather
like that of a fire siren. There was no smoke! Nelson's incredulous
eyes sought the muzzle of the gun and detected issuing from it what
appeared to be a thin, white rod. This shimmering stream of silver
shot straight towards the pine tree, gradually widening and giving off
feathery billows of steam. In a fraction of a moment the target was
completely veiled from sight in a furious pall of clouds which, to
Nelson's great astonishment, did not dissipate nor condense with the
speed of ordinary steam.

"Nava!"

With impressive suddenness the screaming sound faded, leaving a sort
of stunned silence on the gun platform. The gunners stalked back to
their original stations.

* * * * *

Slowly, reluctantly, the mist enveloping the pine tree cleared away
and Nelson felt a chill creeping up his spine. The pine was a good
three hundred yards away, yet now it sagged limp to earth, stripped of
bark, twigs and needles, only the bright yellow trunk and major
branches remaining.

"That tree was a good two feet thick," mused the astounded aviator,
"yet the steam g