“Well, I might as well give up my gyroscope work until you come back from the city of gold, Tom, I can see that,” said Mr. Swift, with a faint smile.  “And if you go, I hope you come back.  I don’t want that mysterious image to be the undoing of you.”

“Oh, I’ll come back all right!” cried Tom confidently.  “Ho! for the city of gold and the images thereof!  I’m going to get ready to start!”

“And so am I!” cried Mr. Damon.  “Bless my shoe strings, Tom, but I’m with you!  I certainly am!” and the little man excitedly shook hands with Tom Swift, while the aged inventor looked on and nodded his head doubtfully.  But Tom was full of hope.

CHAPTER II

AN UNSUSPECTED LISTENER

For a few moments after Tom Swift had announced his decision to start for the city of gold, and Mr. Damon had said he would accompany the young inventor, there was a silence in the workshop.  Then Mr. Swift laid aside the delicate mechanism of the new model gyroscope on which he had been working, came over to his son, and said: 

“Well, Tom, if you’re going, that means you’re going—­I know enough to predict that.  I rather wish you weren’t, for I’m afraid no good will come of this.”

“Now, dad, don’t be talking that way!” cried Tom gaily.  “Pack up and come along with us.”  Lovingly he placed his arm around the bent shoulders of his father.

“No, Tom, I’m too old.  Home is the place for me.”

“Bless my arithmetic tables!” exclaimed Mr. Damon, “you’re not so much older than I am, and I’m going with Tom.  Come on, Mr. Swift.”

“No, I can’t put up with dangers, hardship and excitement as I used to.  I’d better stay home.  Besides, I want to perfect my new gyroscope.  I’ll work on that while you and Tom are searching for the city of gold.  But, Tom, if you’re going you’d better have something more definite to look for than an unknown city, located on a map drawn by some African bushman.”

“I intend to, dad.  I guess when Mr. Illingway wrote his letter he didn’t really think I’d take him up, and make the search.  I’m going to write and ask him if he can’t get me a better map, and also learn more about the location of the city.  Mexico isn’t such a very large place, but it would be if you had to hunt all over it for a buried city, and this map isn’t a lot of help,” and Tom who had shown it to his father and Mr. Damon looked at it closely.

“If we’re going, we want all the information we can get,” declared the odd man.  “Bless my gizzard, Tom, but this may mean a lot to us!”

“I think it will,” agreed the young inventor.  “I’m going to write to Mr. Illingway at once, and ask for all the information he can get.”

“And I’ll help you with suggestions,” spoke Mr. Damon.  “Come on in the house, Tom.  Bless my ink bottle, but we’re going to have some adventures again!”

“It seems to me that is about all Tom does—­have adventures—­that and invent flying machines,” said Mr. Swift with a smile, as his son and their visitor left the shop.  Then he once more bent over his gyroscope model, while Tom and Mr. Damon hurried in to write the letter to the African missionary.