Nathan pressed hard, and the sides came together again, about as easily as usual.
"What!" exclaimed Jonas with surprise. He did not know what to make of the failure of his experiment.
"There must be a leak somewhere," said he. And he took the bellows out of Nathan's hand to look for it.
He found there was a corner, on the side opposite to the one where he had been working, where the leather was open, he having forgotten to nail it down.
"Ah!" said he, "here is the difficulty. When I have nailed this down, we will try again."
"Is that a leak?" said Nathan.
"Yes," said Jonas. "When you worked the bellows, you pressed the air all out through there. I did not know that that was open. Let me nail this down, and then we will begin our experiment regularly."
QUESTIONS.
What was Jonas doing in the shop, when Rollo and Nathan went out to find him? What part of the bellows was out of order? How did he make a new valve? How did he fasten it to its place? Did he nail down only one edge, or both edges? Why did he want the other edge to be left at liberty? How did he prevent its lifting up too far? What was the first experiment which he performed with the bellows, after he had finished the mending? Did it succeed at first? Why not? In working a pair of bellows, where does the air come in? Where does it go out? Why cannot the air escape through the valve where it comes in?