“But how will you get hold of the people who know about phosphorescent paint?” said Tom. “I think you’re in the blindest alley yet.”
CHAPTER XI
As the horses started up, Dorothy refuted Tom’s statement indignantly. “It isn’t a blind alley. It’s a good clue. We’ve run down practically every other line, and now we may as well try this. Everything points to the belief that ‘the man’ is a scientist of no slight ability. Whether he or some one else discovered his high power radio-active force, he must be a good man, or he wouldn’t be able to use it. Now, it seems probable to me that he was working with phosphorescent ink simply because it was the nearest at hand. A man engaged in research like that would be likely to have at least one assistant. I propose to find that assistant.”
“I’d like to see you do it,” said Tom doubtingly. “How would you go to work?”
“I’d advertise,” said Dorothy.
“Advertise,” remarked Tom. “Here’s the way to do it,—‘Wanted, the assistant of the man who is trying to stop all war.’”
“Of course not, stupid,” said Dorothy impatiently. “We’ll advertise for a man who has had some experience in making phosphorescent ink. That’s the line to work on. Don’t you see that since phosphorescent paint acts best with such energy as is given by radio-active substances, that he’s likely to have been using it. There’s such a close relation between phosphorescence and radioactivity, that a man might be working with both.”
“But where will you advertise?” I said. “How can you tell where the man has worked? How can you tell his nationality? I think he is an American, but no one can tell.”