"I'm… almost through,” panted the physicist. He was gasping from exhaustion, as he made his last connections.

"This thing won't save our navies. It can't save them!” groaned Gunner Welk. “How can a machine here inside the moon affect a space-battle sixty million miles away?"

"Ready… now,” gasped Philip Blaine. “Bring me that radite!"

The Planeteers hauled forward the asterium-wrapped mass of radite. With tongs Blaine tore away the protective asterium sheets. The unveiled radite blazed with dazzling white radiance, like a solid chunk of the sun.

Blaine rolled it into the injector-hopper of his power-chambers, with the tongs. He slammed down the lid, and then stumbled toward the huge switchboard set in the cavern wall.

"Stand back, all of you!” he panted.

His trembling hands moved rapidly among the switches and relays of the panel. And the power-chambers below the gleaming sphere began to throb with mounting energy.

Louder and louder throbbed the massive chambers as the radite was disintegrated inside them to produce such concentrated power as had never before been produced in one place. And now the proton-turbines of the great generators were droning loud, adding to the deafening throb of the chambers.

Blaine watched his gauges with feverish eyes, while the Planeteers and their companions stood rigid, watching

"Almost voltage enough,” Blaine murmured hoarsely. “Almost — now!"