Slowly and with majestic grace the battleship dropped until she rested on the water. Her great propellers had been drawn and housed during our descent of the shaft and in their place had been run out the smaller but more powerful water propellers. As these commenced to revolve the ship took up its journey once more, riding the new element as buoyantly and as safely as she had the air.
Phaidor and I were dumbfounded. Neither had either heard or dreamed that such a world existed beneath the surface of Barsoom.
Nearly all the vessels we saw were war craft. There were a few lighters and barges, but none of the great merchantmen such as ply the upper air between the cities of the outer world.
"Here is the harbour of the navy of the First Born," said a voice behind us, and turning we saw Xodar watching us with an amused smile on his lips.
"This sea," he continued, "is larger than Korus. It receives the waters of the lesser sea above it. To keep it from filling above a certain level we have four great pumping stations that force the oversupply back into the reservoirs far north from which the red men draw the water which irrigates their farm lands."