As for the boys themselves, as readers of earlier volumes of this series know, they both lived at High Towers, the estate of Jack’s father, near Nestorville. Jack’s father was an inventor of note, and in our first story, “The Boy Inventors’ Wireless Triumph,” it was described how the boys aided him in many stirring adventures in Yucatan and in the discovery of Tom Jesson’s long missing father, an explorer and naturalist. Since that time Mr. Jesson had made his home with his brother-in-law who, like himself, was a widower. The next volume detailed how Jack and Tom helped an inventor in trouble, and how, after many perils and difficulties, a wonderful vanishing gun was at length brought to perfection in spite of the machinations of a gang of rascals. This volume was called “The Boy Inventors’ Vanishing Gun.”
The third volume has already been referred to. It told how the boys had many exciting times under the ocean and on the surface. The _Peacemaker_ was a wonderful craft and proved of material aid to some Americans beleaguered by blood-thirsty negro revolutionists in Cuba. Through the experiences related in this book both the boys increased their mechanical ability and learned self-reliance and manliness in many a hard test of both those sterling qualities. Had this not been so, it is doubtful if they would ever have had the grit to bring to a triumphant conclusion the construction of the _Wondership_, beset as their way was oftentimes by apparently insurmountable difficulties. But now, as we know, the _Wondership_ lay finished before them. Already they had tested her in flight to ascertain how she bore the added weight. It was this trial, on which she carried side lights, like a ship, that had caused the flurry in the city papers. It had been a complete success, and only the trial by water remained.
Although Mr. Chadwick and Mr. Jesson knew that the boys were engaged on a supreme task, neither had interfered or asked questions. Jack’s father believed in letting his son solve his own problems. He knew that if occasion arose his advice would be called for. But the boys meant to fight out their battle alone. Even the test to take place that evening was to be unwitnessed, or so they hoped. Not till all was an assured success did they intend to invite their parents to inspect their work.