"Well, so they are," said Ned, who, lying on his back, was looking up through the branches, "for I see an acorn."
"Here is another I've found on the ground. What a funny acorn! The cup comes half way over it."
Near by them was a rude building open at the sides, and with thatched roof.
"I'm going to see what is in that building, Wal." And going to it, he cried out, "Come here; it is half full of great sheets of cork."
"So it is, Ned; and these are cork trees, you may depend." Trying the bark with their knives, they found it to be the fact.
"O, my! I'm so glad we came! Only think how much we have learned to-day; and we've got the old castle to see when we go back."
"I never thought before," said Walter, "that a cork tree was an oak, and bore acorns."
Returning, they re-crossed the island.
"How old," asked Walter of the peasant, "must a cork tree be, before they can take off the cork?"
"Twenty years; after that, they take it every ten years, but the cork is not of the best quality till the third stripping."