The professor looked up from his calculations. His face was very pale; his eyes glowed with excitement. The boys had seldom seen the old gentleman so moved.
"You are right, my boy. A planet it surely is," he said to Jack.
"But why have we never seen it before?" demanded Mark.
"For a very good reason," returned the professor, solemnly. "We were never in a position before to behold that planet, save on two occasions."
"Then we have seen it twice before?" asked the puzzled Jack.
"On two occasions we have been enabled to stand off, as it were, and look at that planet as though we were inhabitants of another world—when we went to the moon, and when we went to Mars."
"What do you mean, Professor?" cried Mark.
"It's the earth!" exclaimed Jack Darrow. "It's the earth! We have left the earth—is that it, Professor?"
The old scientist nodded. Phineas Roebach snorted his disbelief, while Washington White gave vent to his trouble of mind most characteristically:
"Goodness gracious gollyation! De fat am suah in de fiah now! We'se done los' de earf an' Buttsy an' me will nebber see our happy home no mo'."