The mule never moved, though Eradicate yanked on the reins, and used a splintered whip with energy.

“I said as how we’d better git along, Boomerang,” went on the darkey, raising his voice, “Dinnah am mos’ ready, an’ I’m goin’ t’ giv yo’ an extra helpin’ ob oats.”

The effect of these words seemed magical.  The mule suddenly came to life, and was about to start off.

“I done thought dat would cotch yo’, Boomerang,” chuckled Eradicate.

“Wait a minute, Rad,” called Tom, who was tearing open the envelope of the telegram.  “I might want to send an answer back by you.  I wonder who is wiring me now?”

He read the message slowly, and Eradicate remarked: 

“‘Taint no kind ob use, Massa Tom, fo’ t’ send a message back wif me.”

“Why not?” asked the young inventor, looking up from the sheet of yellow paper.

“‘Case as how I done promised Boomerang his airman, an’ he won’t do nothin’ till he has it.  Ef I started him back t’ town now he would jest lay down in de road.  I’ll take de answer back fo’ you dis arternoon.”

“All right, perhaps that will do,” assented Tom.  “I haven’t quite got the hang of this yet.  Drop around this afternoon, Rad,” and as the colored man, who, with his mule Boomerang, did odd jobs around the village, started off down the highway, in another cloud of dust, Tom Swift resumed the reading of the message.

“Hum, this is rather queer,” he mused, when having read it once, he began at it again.  “It must have cost him something to send all this over the wire.  He could just as well have written it.  So he wants my help, eh?  Well, I never heard of him, and he may be all right, but I had other plans, and I don’t know whether I can spare the time to go to Philadelphia or not.  I’ll have to think it over.  An electric airship, eh?  He’s sort of following along the lines of my inventions.  Wants my aid—­hum—­well, I don’t know—­”

Tom’s musings were suddenly cut short by the approach of an elderly gentleman, who was walking slowly down the path that led from the house to the country highway which ran in front of it.

“A telegram, Tom?” asked the newcomer.

“Yes, dad,” was the reply.  “I was just coming in to ask your advice about it.  Eradicate brought it to me.”

“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!’”