of worriment.

"Father has just sent me a message," he said. "It's a warning flashed
through space! He's been trying to get it to me since yesterday!"

"What is it?" asked Mr. Jenks, rising from his seat.

"The mysterious man is aboard the airship--hidden away!" cried Tom.
"That's what Eradicate was trying to call to our attention as we started
off. Eradicate saw his face at a rear window, and tried to warn us! The
mysterious man is a stowaway on board!"

CHAPTER X--DROPPING THE STOWAWAY

Tom's excited announcement startled Mr. Damon and the others as much as
if the young inventor had informed them that the airship had exploded
and was about to dash with them to the earth. The men leaped to their
feet, and stared at the lad.

"A stowaway on board!" cried Mr. Damon. "Bless my soul! How did he--"

"Are you sure that message is straight?" asked Mr. Jenks. "Did Eradicate
see the man?"

"He says he did," answered Tom. "The man is hidden away on board
now--probably among the stores and supplies."

"Bless my tomato sauce!" exploded Mr. Damon. "I hope he doesn't eat them
all up!"

"We must get him out at once!" declared Mr. Jenks.

"I knew something would happen on this voyage," came from Mr. Parker. "I
predicted it from the first!"

Tom thought considerable, but he did not answer the scientist just
then. Another communication was coming to him by wireless. He listened
intently.

"Father says," the lad told his companions "that Eradicate only had
a glimpse of the man at the last moment. He was looking from the rear
storeroom window--he's the same man who called on me that time--Rad
remembers him very well."

"Bless my shoes! What's to be done?" inquired Mr. Damon, looking around
helplessly.

"We must get him out, that's all," decided Mr. Jenks; with vigor. "Get
him out and drop him overboard!"

"Drop him overboard!" cried Mr. Parker, in horror.

"Not exactly, but get rid of him," proceeded the diamond seeker. "That
man is one of my enemies. He has been sent by the band of diamond makers
hidden among the mountains, to spy on me, and, if possible, prevent me
from seeking to discover their secret. He tried to work on Tom's Swift's
fears, and frighten him from using his airship on this quest. Then, when
he failed, the man must have sneaked into the shed, and hidden himself
in the ship. We must get rid of him, or he may wreck the Red Cloud!"

"That's so!" cried Tom. "We must try to capture him. I thin