“It’s a light-weight rocket mortar,” explained Kennedy, ramming something into it. “You’ll see in a moment. Stand back, all of you—off the float—on the dock.”
Suddenly there came a deep detonation from the mortar and a rocket shot out and up in a long, low parabola. Kennedy rushed forward, and another detonation sent a second far out in a different angle.
“What is it?” gasped Burke, in amazement.
“Look!” called Kennedy, elated.
Another instant, and from every quarter of the harbor there seemed to rise, as if from the waves, huge balls of fire, a brilliant and luminous series of flames literally from the water itself. It was a moonless night but these fires seemed literally to roll back the Cimmerian darkness.
“A recent invention,” explained Craig, “light-bombs, for use at night against torpedo-boat and aeroplane attacks.”
“Light-bombs!” Burke repeated.
“Yes, made of phosphide of calcium. The mortar hurls them out, and they are so constructed that they float after a short plunge in the water. You see, the action of the salt water automatically ignites them merely by contact and the chemical action of the phosphide and the salt water keeps them phosphorescing for several minutes.”
As he talked he shot off some more.
“Kennedy, you’re a genius,” gasped Burke. “You’re always ready for anything.”