"I—I—-," began Tom.
"Promise!" insisted the aged inventor, trying to rise. Dr. Hendrix made a hasty move toward the bed.
"Promise!" whispered the surgeon to Tom.
"I—I promise!" exclaimed Tom, and the aged inventor sank back with a smile of satisfaction on his pale face.
"Now you must go," said Dr. Gladby to Tom. "He has talked long enough. He must sleep now, and get up his strength."
"Will he get better?" asked Tom, anxiously.
"We can't say for sure," was the answer. "We have great hopes."
"I don't want to enter the race unless I know he is going to live," went on Tom, as Dr. Gladby followed him out of the room.
"No one can say for a certainty that he will recover," spoke the physician. "You will have to hope for the best, that is all, Tom. If I were you I'd go in the race. It will occupy your mind, and if you could send good news to your father it might help him in the fight for life he is making."
"But suppose—suppose something happens while I am away?" suggested the young inventor.