"What a monstrous sheet of birch bark!"
This sheet, which Marco lifted up from the ground where it was lying, was about four feet long and two feet wide. Marco wondered that so large a sheet could be got from any tree.
"What a monstrous tree it must have been!" said he to Forester.
"No," said Forester, "not very large. This sheet is about four feet long, which would make the tree only about sixteen inches in diameter."
"How do you prove that?" asked Marco.
"Why, the distance through a tree is about one third the distance round it," replied Forester. "Now, this bark grew around the tree, and it is about four feet long. Four feet is forty-eight inches, and one-third of forty-eight is sixteen. Now, sixteen inches in diameter would not be a very large tree."
"I mean to try this bark on some of these trees," said Marco, "to see how big a tree it will fit."
So Marco took up the sheet of bark. It was white and clean, especially on the outside, having been blanched by the summer rains. Marco, in order to carry the sheet more easily, put it upon his shoulders, drawing it up around his neck like a shawl.
"Cousin Forester," said he, "see my shawl. It would do for an umbrella, if I only had a handle."