"What, with his mule, Boomerang?" and the gentleman seemed much amused. "How did he ever get up speed enough to deliver a telegram?"
"Oh, Eradicate has some special means he uses on his mule when he's in a hurry. But listen to this message, dad. It's from a Mr. Hosmer Fenwick, of Philadelphia. He says:"
"'Tom Swift--Can you come on to Philadelphia at once and aid me in perfecting my new electric airship? I want to get it ready for a flight before some government experts who have promised to purchase several if it works well. I am in trouble, and I can't get it to rise off the ground. I need help. I have heard about your airship, and the other inventions you and your father have perfected, and I am sure you can aid me. I am stuck. Can you hurry to the Quaker City? I will pay you well. Answer at once!'"
"Well?" remarked Mr. Swift, questioningly, as his son finished reading the telegram. "What are you going to do about it, Tom?"
"I don't exactly know, dad. I was going to ask your advice. What would you do? Who is this Mr. Fenwick?"
"Well, he is an inventor of some note, but he has had many failures. I have not heard of him in some years until now. He is a gentleman of wealth, and can be relied upon to do just as he says. We are slightly acquainted. Perhaps it would be well to aid him, if you can spare the time. Not that you need the money, but inventors should be mutually helpful. If you feel like going to Philadelphia, and aiding him in getting his electric airship in shape, you have my permission."
"I don't know," answered Tom, doubtfully. "I was just getting my monoplane in shape for a little flight. It was nothing particular, though. Dad, I think I will take a run to Philadelphia, and see if I can help Mr. Fenwick. I'll wire him that I am coming, to-morrow or next day."
"Very well," assented Mr. Swift, and then he and his son went into one of the shops, talking of a new invention which they were about to patent.
Tom little knew what a strange series of adventures were to follow his decision to go to the Quaker City, nor the danger involved in aiding Mr. Fenwick to operate his electric airship.