on. These could not penetrate the
canopies of the other ships, but the one which had turned turtle was
blown to fragments.

The squadron attempted to change its course and dodge the barrier in
front of it. But a new barrier of blazing detonations and churned earth
appeared on its flanks. In a matter of minutes it was ringed around,
thanks to the skill of our fire control.

One by one the wallowing ships plunged into holes from which they could
not extricate themselves. One by one their canopy rays were shut off, or
the ships somersaulted off the knolls on which they perched, as their
canopies melted the ground away from around them. So one by one they
were destroyed.

Thus the second ground sortie of the Hans was annihilated.

CHAPTER IV

Han Electrono-Ray Science

At this period the Hans of Nu-Yok had only one airship equipped with
their new armored repeller ray, their latest defense against our tactics
of shooting rockets into the repeller rays and letting the latter hurl
them up against the ships. They had developed a new steel alloy of
tremendous strength, which passed their _rep_ ray with ease, but was
virtually impervious to our most powerful explosives. Their supplies of
this alloy were limited, for it could be produced only in the Lo-Tan
shops, for it was only there that they could develop the degree of
electronic power necessary for its manufacture.

This ship shot out toward our lines just as the last of the groundships
turned turtle and was blown to pieces. As it approached, the rockets of
our invisible and widely scattered gunners in the forest below began to
explode beneath its _rep_ ray plates. The explosions caused the great
ship to plunge and roll mightily, but otherwise did it no serious harm
that I could see, for it was very heavily armored.

Occasionally rockets fired directly at the ship would find their mark
and tear gashes in its side and bottom plates, but these hits were few.
The ship was high in the air, and a far more difficult target than were
its _rep_ ray columns. To hit the latter, our gunners had only to gauge
their aim vertically. Range could be practically ignored, since the
_rep_ ray at any point above two-thirds the distance from the earth to
the ship would automatically hurl the rocket upward against the _rep_
ray plate.

As the ship sped toward us, rocking, plunging and recovering, it began
to beam the forest below. It was equipped with a superbeam too, which
cut