an airship coming along you can slip up in your noiseless one, overhaul it, and make them submit to a search."
"But I won't have any authority to do that," objected Tom, who really did not care for the commission.
"Oh, I'll see that you get the proper authority all right," said Mr. Whitford significantly. "I made you a temporary deputy to-night, but if you'll undertake this work, to catch the smugglers in their airships, you will be made a regular custom official."
"Yes, but supposing I can't catch them?" interposed our hero. "They may have very fast airships, and"
"I guess you'll catch 'em all right!" put in Ned, who was at his chum's side as they walked along a quiet Shopton street in the darkness. "There's not an aeroplane going that can beat yours, Tom."
"Well, perhaps I could get them," admitted the young inventor. "But"
"Then you'll undertake this work for Uncle Sam?" interrupted Mr. Whitford eagerly. "Come, Tom, I know you will."
"I'm not so sure of that," spoke Tom. "It isn't going to be as easy as you think. There are many difficulties in the way. In the first place
