While Mr. Temple conversed with Mr. Hampton, in whose oil operations he naturally was interested, as he had invested a considerable sum in them, the boys talked in whispers.  They were frankly envious of Jack’s adventures and wishing that they, too, were on the ground.  Suddenly, something said by his father caught Bob’s attention, and he stopped talking to Frank and turned to listen.

“Well, I’ll tell you, Hampton,” Bob heard his father say, “I’ve got a sharp attack of spring fever.  I think I need a vacation.  And if these two youngsters of mine will let me go along, I’ll come out with them.”

Bob couldn’t control his eagerness.  Going up to his father’s side, he pulled insistently at his sleeve.

“Wait a minute, Hampton,” said Mr. Temple.  “Bob has something on his mind.”  He removed the receiver and regarded his son with a twinkle.  “Out with it,” he said.  “I suppose that quite shamelessly you’ve been listening to my conversation.”

“No, Dad, Honest Injun,” protested Bob.  “Only I couldn’t help overhearing that part about you going with us.  Say, Dad, we’ll go by airplane, won’t we?”

Mr. Temple groaned in mock dismay.  “Run along,” he said.  “You’ll drive me crazy with that airplane business.”  Then, once more adjusting his headpiece, he resumed his interrupted conversation with Mr. Hampton.

Bob returned to Frank, wearing a wide grin.  “I couldn’t resist putting over that piece of propaganda,” he said.

“Do you think he’ll let us fly?” whispered Frank.

“Say,” answered Bob scornfully, “now that Dad has decided to go along, it’s a cinch.  He’s as crazy about flying as Mr. Hampton is about the radiophone.”

“Ssst.  Ssst,” came a warning whisper, interrupting them.  They swung about to face the door into the power house.  It was part-way open and the round good-natured face of Tom Barnum, filled now with anxiety, was framed in the opening.  Tom was the mechanic-watchman.  He beckoned, and the boys tiptoed across the room and into the power house, closing the door behind them.  Old Davey, caretaker at the Hampton home, stood there, wringing his hands.

“What is it?  What’s the matter?” Frank Merrick asked sharply.

“Old Davey says there’s a thief up at the house,” said Tom.

“A thief?” said Bob.  “How do you know?”

“Seed him myself with my own two eyes,” quavered Old Davey, a little old man who was a pensioner of Mr. Hampton’s.  “He’s a big dark ugly-lookin’ feller.  I seed him a-sneakin’ into the house through the cellar door I left open to git out some garden tools.”

“Then what did you do?” asked Frank.

“I run,” said Old Davey, simply.  “Leastways I tried to, but my legs ain’t what they used to be.”

“Come on, Bob,” said Frank, impulsively.  “Let’s go see.”

“Not till we tell Dad, first,” said Bob, as always the cooler.

Re-entering the sending room, Bob once more gained the attention of his father, who still was in conversation with Mr. Hampton.  He told him what Old Davey had reported.  Mr. Temple readjusted the headpiece and swung about to the transmitter.