On the following morning the boys, with the exception of Stacy, reported at Tom Phipps's shack ready for the day's sight-seeing in the zinc mine far underground. The assistant superintendent had made ready a large basket of food, as the party was to dine in the mine.
Professor Zepplin was enthusiastic. It was an opportunity that he had much desired.
"I understand," he said, fixing Tom Phipps with a stern glance of inquiry, as they started for the mine, "that Silurian species have been found in the limestones hereabouts. Also that others believed to be Cambrian have been discovered. Is this in accordance with your experience?"
"I think I understand to what you refer," answered Tom gravely. "I can't say that I am familiar with the species, however."
"If Chunky was here he would want to know if it were something to eat," laughed Ned. "I'm not very certain myself whether it is or not."
"You'll be wiser by-and-by," said Tad.
Entrance to the mine was gained through a shaft leading straight down for a great many feet. A windlass and bucket was employed to carry the miners up and down, while through another and larger shaft automatic buckets raised the zinc ore to the surface.
All of the party could not be accommodated in the passenger bucket at one time, so it was necessary to make two trips, Mr. Phipps returning with the vehicle to see that the rest of the boys got down safely.
Descending into the cool, damp darkness was a new experience for them. And while the sensations were not particularly pleasant, they agreed that it was the most interesting journey they ever had taken.
"How far down do we go?" asked Walter.