thing is added to the matrix to
color or make opaque the finished metal. It is in the preparation of
this metal that salt is indispensable. It acts only as a catalyst, being
recovered afterward, but neither nation has ever had enough salt to make
all the armor they want."

"Aren't those monsters--karlono, I think you called them--covered by the
same thing? And what are those animals, anyway?" Dorothy asked.

"Yes, they are armored with arenak, and it is thought that the beasts
grow it, the same as fishes grow scales. The karlono are the most
frightful scourge of Osnome. Very little is known of them, though every
scientist has theorized upon them since time immemorial. It is very
seldom that one is ever killed, as they easily outfly our swiftest
battleships, and only fight when they can be victorious. To kill one
requires a succession of the heaviest high-explosive shells in the same
spot, a joint in the armor; and after the armor is once penetrated, the
animal is blown into such small fragments that reconstruction is
impossible. From such remains it has been variously described as a bird,
a beast, a fish, and a vegetable; sexual, asexual, and hermaphroditic.
Its habitat is unknown, it being variously supposed to live high in the
air, deep in the ocean, and buried in the swamps. Another theory is that
they live upon one of our satellites, which encounters our belt of
atmosphere every karkam. Nothing is certainly known about the monsters
except their terrible destructiveness and their insatiable appetites.
One of them will devour five or six airships at one time, absorbing the
crews and devouring the cargo and all of the vessels except the very
hardest of the metal parts."

"Do they usually go in groups?" asked Crane. "If they do, I should think
that a fleet of warships would be necessary for every party."

"No, they are almost always found alone. Only very rarely are two found
together. This is the first time in history that more than two have ever
been seen together. Two battleships can always defeat one karlon, so
they are never attacked. With four battleships Nalboon considered his
expedition perfectly safe, especially as they are now rare. The navies
hunted down and killed what was supposed to be the last one upon Osnome
more than a karkam ago, and none have been seen since, until we were
attacked...."

* * * * *

The gong over the door sounded and the Kondalians leaped to their