Tom fairly rushed into the building, much of the space of which, was taken up by machinery, queer tools and odd devices, many of them having to do with the manufacture of aeroplanes, for Tom had as many of them as some people have of automobiles.

"I say, dad!" cried Tom, waving the letter above his head, "what do you think of this? Listen to--"

"Easy there now, Tom! Easy, my boy, or you'll oblige me to do all my work over again," and an aged man, beside whom a younger one was standing, held up a hand of caution, while with the other hand he was adjusting some delicate piece of machinery.

"What are you doing?" demanded the son.

"Bless my scarf pin!" exclaimed the other man--Mr. Wakefield Damon--"Bless my rubbers, Tom Swift! What should your father be doing but inventing something new, as he always is. I guess he's working on his new gyroscope, though it is only a guess, for he hasn't said ten words to me since I came out to talk to him. But that's like all inventors, they--"

"I beg your pardon, Mr. Damon," spoke Mr. Swift with a smile, "I'm sure--"

"Say, can't you listen to me for five minutes?" pleaded Tom. "I've got some great news--simply great, and your gyroscope can wait, dad. Listen to this letter," and he prepared to read it.

"Who's it from?" asked Mr. Damon.

"Mr. Jacob Illingway, the African missionary whom you and I rescued, together with his wife, from the red pygmies!" cried Tom. "Think of that! Of all persons to get a letter from, and such a letter! such news in it. Why, it's simply great! You remember Mr. and Mrs. Illingway; don't you Mr. Damon? How we went to Africa after elephant's tusks, with Mr. Durban the hunter, and how we got the missionaries away from those little savages in my airship--don't you remember?"

"I should say I did!" exclaimed Mr. Damon. "Bless my watch chain--but they were regular imps--the red Pygmies I mean, not the missionaries. But what is Mr. Illingway writing to you about now, Tom? I know he sent you several letters since we came back from Africa. What's the latest news?"