accordance with the instructions from the old man. The inventor and
Washington were the only ones visible in the cabin.

"Why don't you turn up the light?" went on the visitor in fretful tones.
"Are you sure no one is here to learn our secret?"

"Do you see any one?" asked the professor, not wishing to disclose the
boys' presence. "Do you think I am so foolish as to waste the labor and
toil of years?"

"I didn't think so," said the man, "but as I came along I thought I saw
lights in the balloon shed."

"Very likely," admitted Mr. Henderson coolly. "Washington and I were
out there doing some work."

"All right," was the rather ungracious answer. "I have those chemicals
you wanted."

"Give them to me!" implored the old man in an anxious tone. "I thought
you would never bring them."

"Oh, I don't forget so easily. Here you are," and the newcomer passed
over a package. "Now when are you going to sail?"

"In about a week," answered the inventor.

"Then I guess I'll stay until you go," spoke the stranger. "I don't want
to be left behind."