Suddenly the silence was broken by a cry.

“Help! Help!” shouted a voice. “Help! I’ve got the snakes, but I’m caught and they may get away! Help!”

“The professor!” shouted Ned.

“And a snake has him!” added Bob.

“It can’t be,” declared Harvey Brill. “The luminous snakes are only little things. They couldn’t hurt a cat.”

But again came the cry:

“Help! Help! Help me save the luminous snakes!”

“He must have ’em!” declared Jim Nestor.

The airship drifted around a pile of rocks, and there, [lying at full length on the ground], his foot caught under a big stone, [was Professor Snodgrass]. In either hand he held a wriggling serpent.