"All right, Rad, there'll be plenty for you to do when the time comes," said the inventor. And he could not help a feeling of sadness as he left the colored man's room.
"I wonder if he is doomed to be blind the rest of his life," thought Tom. "I hope not, for if he does it will be my fault for letting him try to mix those chemicals."
But, hoping for the best, Tom plunged into the work ahead of him. He did not want to offer his aerial fire extinguisher to any large city until he had perfected it, and he was now laboring to that end.
One day, in midsummer, after weary days of toil, Tom took Ned out for a ride in the machine which had been fitted up to carry a large supply of the chemical mixture, a small but powerful searchlight, and other new "wrinkles" as Tom called them, not going into details.
"Any special object in view?" asked Ned, as Tom headed across country. "Are you going to put out any more tree fires?"
"No, I haven't that in mind," was the answer. "Though of course if we come across a blaze, except a brush fire, I may put it out. I have the bombs here," and Tom indicated the releasing lever.
"What I want to try now is the stability of this with all I have on board," he resumed. "If she is able to travel along, and behave as well as she did before I made the changes, I'll know she is going to be all right. I don't expect to put out any fires this trip."
In testing the ship of the air Tom sent her up to a good height, heading out over the open country and toward a lake on the shores of which were a number of summer resorts. It was now the middle of the season, and many campers, cottagers and hotel folk were scattered about the wooded shore of the pretty and attractive body of water.
Tom and Ned had a glimpse of the lake, dotted with many motor boats and other craft, as the airship ascended until it was above the clouds. Then, for a time, nothing could be seen by the occupants but masses of feathery vapor.
"She's working all right," decided Tom, when he found that he could perform his usual aerial feats with his craft, laden as she was with apparatus, as well as he had been able to do before she was so burdened. "Guess we might as well go down, Ned. There isn't much more to do, as far as I can see."