"I'm afraid he's dying," he said.
"Dying?" cried jack in dismay.
"Yes; and if he expires, the secret of the wonderful power will die with him. We will never be able to get to Mars!"
The professor placed his ear against the breast of the unconscious man.
"There is still a spark of life," he remarked. "Perhaps I can save him. I will try my electric remedy."
He got up and hurried to the house. Mr. Henderson had invented a number of medical appliances, not the least of which was an affair, different from an electric battery in that it allowed a current to be administered internally. It was this that he now decided to try on the unfortunate German.
He came back in less than a minute with a curious machine. It was shaped like a box, but on the outside had a number of shiny knobs, and several wires ending in brass handles.
Professor Henderson placed a brass handle in each of the palms of the German, directing Mark and jack to hold them there. Then he placed several of the shining knobs at the back of his head, and ran a long wire around his waist.
"Now, Andy," ordered the inventor, "if you will take hold of this rod and place the end of it on his tongue when I open his mouth, I think we may be able to revive him."
This was done, and Mr. Henderson turned on the current. There was a buzzing sound from the box, and a slight tremor was visible throughout the whole body of the unconscious man.