irmation of
whether there is or not heavy absorption of waves in the upper levels of
our own atmosphere. If successful it would indicate a reasonably good
reflection coefficient at the surface of the moon--the power of the
moon's surface to act as a joint agent in the perfection of the signal.

The signal might have some bearing also on whether the moon has an
atmosphere--something pretty much settled already by astronomical
observation. It would also lead to the possibility of fairly accurate
determination of wave velocity in free space, all of interest to
science, either confirming existing theories or establishing new ones.

The Pirate Planet

PART TWO OF A FOUR-PART NOVEL

_By Charles W. Diffin_

It is war. Interplanetary war. And on far distant Venus two
fighting Earthlings stand up against a whole planet run amuck.

WHAT HAS GONE BEFORE

A flash of light on Venus!--and at Maricopa Flying Field Lieutenant
McGuire and Captain Blake laugh at its possible meaning until the
radio's weird call and the sight of a giant ship in the night sky prove
their wildest thoughts are facts. "Big as an ocean liner," it hangs in
midair, then turns and shoots upward at incredible speed until it
disappears entirely, in space!

McGuire goes to Mount Lawson observatory, and there he sees the flash on
Venus repeated. Professor Sykes, who had observed the first flash,
confirms it and sees still more. He sees the enveloping clouds of Venus
torn asunder, and beneath them an identifying mark, a continent shaped
like the letter "L."

And then the great ship comes again. It hovers above the observatory and
settles slowly down.

[Illustration: "Hold them off as long as you can!"]

Back at Maricopa Field, Captain Blake has tested a new plane for
altitude, and is now prepared to interview the stranger in the higher
levels. McGuire's frantic phone call sends him out into the night with
the 91st Squadron of planes in support. It is their last flight, for all
but Blake. The invader smothers them in a great sphere of gas, but
Blake, with his oxygen flasks, flies through to crash beside the
observatory. Only Blake survives to see the enemy land, while strange
man-shapes loot the buildings and carry off McGuire and Sykes.

A bombardment with giant shells dispels the last doubt of the earth
being under attack. The flashes from Venus at regular intervals spout
death and destruction upon the earth; a mammoth gun, sunk into the
p