About half a mile city-wards from the plant Dave passed through a square devoted to public park purposes. He sat down on a tree-shaded rustic bench. There, alone, quiet and undisturbed, he set his wits at work.
Whoever it was who had committed the theft must have been a professional airman. Dave formulated a plan to ask Mr. Randolph if anybody in Bolton, or any employee of the plant was missing. In case this was not discovered then some stranger must have come to Bolton. There might be a trace found of the party at some of the hotels.
"There's a bit of detective work to do by some one besides myself," decided Dave. "I'm going to suggest this plan to Mr. Randolph."
"Hello, boss," spoke an approaching voice as Dave got up to return to the plant.
He observed a man he had noticed on a bench directly opposite to the one he had occupied sidling towards him. The fellow was ragged and trampish looking. There was a queer leer in his face and his eyes were fixed on the coat Dave wore.
"Well, what is it?" inquired Dave.
"Excuse a question, matey?"
"Oh, that's all right."
"Noticed a badge you're wearing," said the tramp.
"Oh, that?" spoke Dave lifting his hand to his coat lapel, and wondering at the man been so observant.