The red men had always considered it a miracle that caused great columns of water to spurt from the solid rock of their reservoir sides to increase the supply of the precious liquid which is so scarce in the outer world of Mars.
Never had their learned men been able to fathom the secret of the source of this enormous volume of water. As ages passed they had simply come to accept it as a matter of course and ceased to question its origin.
We passed several islands on which were strangely shaped circular buildings, apparently roofless, and pierced midway between the ground and their tops with small, heavily barred windows. They bore the earmarks of prisons, which were further accentuated by the armed guards who squatted on low benches without, or patrolled the short beach lines.
Few of these islets contained over an acre of ground, but presently we sighted a much larger one directly ahead. This proved to be our destination, and the great ship was soon made fast against the steep shore.
Xodar signalled us to follow him, and with a half dozen officers and men we left the battleship and approached a large oval structure a couple of hundred yards from the shore.
"You shall soon see Issus," said Xodar to Phaidor. "The few prisoners we take are presented to her. Occasionally she selects slaves from among
