"Will you answer a straight question?" persisted the boy.

"Certainly!"

"Then answer it. What are we here for?"

"We are here," replied Will, "to secure the print of a thumb!"

"Has the shock of this incident turned your head?" asked Tommy.

"I answered the question correctly!" replied Will. "We came all the way from Chicago to find the print of a man's right thumb!"

"Where do you expect to find it?" demanded Sandy.

"Somewhere among the mountains and glaciers," smiled Will.

"I can get all the thumb prints I want on South Clark street!" declared Tommy. "Of course, it's fun to come out here, under any pretext whatever, but I think Mr. Horton might have given us a more sensible errand than that. This is worse than the trip to the coal mine!"

"Now tell us the excuse Mr. Horton gave for wanting this print of a man's right thumb," smiled Sandy.