"We've tapped some maple trees for sap," said Donald.
"And we could see it run right out of the tree," said Susie.
"I've told the children how we used to make maple sugar in New England," said Mrs. Leonard. "Do you remember, Robert, what a quantity of sap it took to make just a little sugar?"
"Yes, and I also remember how long I thought it took to boil it down into the wax I was so fond of."
"About thirty gallons of sap can be taken from one tree each year," said
Mr. Leonard.
"But I should think that would hurt the tree," said Frank.
"No," replied Uncle Robert, "for the hole they make is only about an inch across. If they were to cut all around the tree, you see, it would stop the running of the sap and kill the tree."
"That is called girdling," said Mr. Leonard. "They used to clear off hundreds of acres of land in that way when this country was first settled. Instead of cutting down the trees, they girdled them near the ground. In a very short time they died, because they could get no food from the earth. The dead trees lost their strength, and a strong wind would blow them over. Then they were piled up and burned."
"How do you know when a tree is dying?" asked Uncle Robert.
"The leaves turn yellow," said Donald.