It was hard work, for he had to labor with his arms stretched up in the air, and any one who has even put up pictures knows what that means. The muscles are unaccustomed to the strain. The German scientist, though a strong man, had to rest at frequent intervals.
"We're falling rapidly," announced Jack, in a low voice, as he looked at the height gauge.
"I am doing all I can," answered Mr. Roumann. "I think I will soon be able to right the craft."
He labored desperately, but he was at a disadvantage, for the Annihilator was not now moving smoothly through space. With the stopping of the motor she was falling like some wobbly balloon, swaying hither and thither in the ether currents.
But Professor Roumann was not one to give up easily. He kept at his task, aided occasionally by Professor Henderson and by the boys whenever they could do anything.
Finally the German cried out:
"Ah, I have discovered the trouble. It is that scoundrel Axtell! See!" And reaching into the interior of the machine he pulled out a small magnet. To it was attached a card, on which was written:
"I told you I would have my revenge!" It was signed with Axtell's name.
"This was the dastardly plot he evolved," said Professor Roumann. "He slipped this magnet into the equilibrium machine, knowing that in time it would cause a deflection of the delicate needles, and so shift the centre of gravity. He must have done this as a last resort, and to provide for his revenge in case we discovered him on board after we started. It was a cruel revenge, for had I not discovered it we would soon all be killed."
"Is the machine all right now?" asked Jack.