VALVE MAKING.
One morning, when Rollo awaked, he heard a sharp clicking against the
window.
"Nathan," said he, "Nathan, I believe there is a snow-storm."
But Nathan was too sleepy to hear or understand.
Rollo looked up, but there was a curtain against the window, and he
could not see very well. He listened. He heard a low, moaning sound made
by the wind, and a continuance of the sharp clicking which he had heard
at first.
When he had got up, and dressed himself, he found that there was a
violent snow-storm. At first he was glad of it, for he liked
snow-storms. But then, pretty soon, he was sorry, for it had been winter
a long time, and he was impatient for the spring.
After breakfast, he and Nathan read and studied for two hours, under
their mother's direction. When they were released from these duties,
Rollo proposed to Nathan that they should go out into the shed, and see
how the storm came on. There was a large door in the shed, opening
towards the street, where they could stand, protected from the wind, and
see the drifts of snow.
They accordingly put on their caps, and went. They found that the snow
was pretty deep. It was heaped up upon the fence and against the
windows; and there was a curious-shaped drift, with the top curled over
in a singular manner, running along from the corner of the shed towards
the garden gate.
"Ah," says Rollo, "when it clears up, I mean to go and wade through it."
"And I too," said Nathan.
"O Nathan," said Rollo, "it is over your head."
"Hark!" said Nathan; "who is that pounding in the barn?"
"It is Jonas, I suppose," said Rollo. "I mean to go out and see what he
is doing."
"How are you going to get there?" said Nathan.
"O, I can put on my boots," said Rollo, "and go right out through the
snow."
"I wish _I_ could go," said Nathan.
"Well," said Rollo, "I can carry you on my back."
Nathan clapped his hands at this proposal, being doubly pleased at the
prospect of both getting into the barn to see what Jonas was doing, and
also of having a ride, on the way.
So Rollo put on his boots, while Nathan went and got Rollo his straps,
to fasten his pantaloons around them. When all was ready, Rollo sat down
upon the step of the door, in order that Nathan might get on easily.
"We'll play that I am a camel," said Rollo, "and that I'm kneeling down
for you to get on."
"Do camels kneel down," said Nathan, "when the men want to ride?"
"Yes," said Rollo; and so saying, he rose laboriously, with his heavy
burden upon his shoulders. He staggered along with some difficulty, but
yet safely, until he came to the great drift; and, after wallowing into
the midst of it, he lost his balance, and both camel and driver rolled
over together into the snow. The snow got up under Nathan's sleeve, and
he began to cry.
"O Nathan," said Rollo, "don't cry. I'll run and get Jonas to come and
carry you in."
So Rollo ran into the barn, and called to Jonas to come quick. Jonas
laid down his hammer upon the bench, and followed Rollo. He found Nathan
in the snow, and took him up in his arms, and carried him into the barn.
As soon as he got him under cover, he brushed the snow off, and told him
not to cry. "I've got a fire in the shop," said he, "and you shall see
me do my work. I'm mending the bellows."
So he led Nathan through the barn, and thence along under a shed to a
sort of shop-room, where there was a large fireplace and a fire. Rollo
put on some sticks, which made a great blaze; and so Nathan soon got
warm and dry, and forgot all his troubles. Then Jonas sat him up, upon a
high stool, near the bench, where he could see him work. He was just
drawing out some of the nails, by which the leather of the bellows was
nailed to the sides.
"What is the matter with the bellows?" said Nathan.
"The valve is out of order," replied Jonas.
"The valve," repeated Nathan; "what is the valve?"
"The valve is a kind of clapper," said Jonas. "I will show it to you in
a few minutes."
So Jonas proceeded to take off the leather from one of the sides of the
bellows. There was a hole in one of the sides, but no hole in the other.
Nathan had often noticed the hole, but he did not know what it was for.
"What is the hole for?" said Nathan.
"That is to let the air in," said Jonas.
"What do they want the air to come in for?" said Nathan.
"To make wind of," said Jonas.
"Do they make wind out of air?" said Nathan.
"Yes," said Jonas, "they get the bellows full of air, and then blow it
out through the nose, and that makes wind."
"Wind is air, put in motion," said Rollo. "I read it in a book."
By this time, Jonas had taken off the leather so far that Nathan could
see into the bellows. He saw that there was a little clapper over the
hole, in one of the sides of the bellows.
"Is that the valve?" said he to Jonas.
"Yes," said Jonas.
"What is it for?" said Nathan.
"It is to keep the wind from coming out of that hole."
"Why don't they want the wind to go out of that hole?" said Nathan.
"Because," said Jonas, "they want it to go to the fire,--to blow the
fire."
"You see," said Rollo, "it can't go out of the hole, and so it has to go
out of the long nose, which is pointed towards the fire."
"What makes it go out at all?" said Nathan.
"Why, when we blow the bellows, we press the two sides together, and
that presses the wind out. It can't go out of the hole whence it came
in, because the clapper stops it up, and so it goes out the long nose,
right into the fire, and makes the fire burn."
By this time, Jonas had got the leather off so far, that he could get at
the clapper to mend it. He told the boys that it was old and worn out,
and he must make a new one.
"How are you going to make it?" said Rollo.
"You'll see," said Jonas, "if you watch me closely."
So Jonas took some leather, and cut out a piece, of an oblong shape, a
little wider than the hole, and about twice as long. Then he laid this
down over the hole. It covered it entirely. Then he took some small
carpet nails, and nailed one of the ends of the leather down to the
board. Then Jonas put his hand down under the board, and run one of his
fingers up through the hole, and pushed the leather up a little way.
"There," said he to the boys, "you see I have nailed the leather, so
that, when it lies down in its place, it covers the hole completely; and
yet I can push it up a little with my fingers, so that there will be an
opening."
Then Jonas cut a small leather strap, and nailed one end of it down upon
one side of the clapper, and the other end upon the other side of the
clapper. He put one little carpet nail into each end of the strap. The
strap, when it was nailed, passed directly across the clapper or valve.
It was not drawn tight across, but it lay upon the clapper loosely. The
ends were nailed tight, but the middle rested loosely upon the clapper.
"Now," said Jonas, "I can push the clapper up a little way, but I can't
push it far. The strap keeps it from coming up far."
"But why," said Nathan, "do you want it to go up at all?"
"To let the air in," said Jonas. "When I get the leather all nailed on
again, I'll show you the whole operation of it."
"And you can be telling us about it in the mean time," said Rollo.
"Well, then," said Jonas, "when I lift up the upper side of the bellows
by the handle, to blow, the air comes in by the hole. The clapper lifts
up a little way, and lets it in. Then, when I press down the handle
again, it presses the air out through the nose, because it can't go back
through the valve hole."
"Why not?" said Nathan.
"Because," said Jonas, "the valve falls down over the hole, and stops it
up. It is made so as to lift up easily, and then to fall down and cover
the hole exactly, and prevent the air going out the same way it came in.
So, as it cannot get out by the valve, it has all to go out through the
nose. If the nose were stopped up, it could not get out at all."
"And what then?" said Rollo.
"Why, then," replied Jonas, "you could not bring the two sides of the
bellows together again. The air between would keep them apart."
"I should like to try," said Rollo.
"Well," said Jonas; "and there are some other experiments you may
perform with it too."
At length, Jonas said that he had got the leather all nailed on, and
they might try the experiment. He took hold of the nose of the bellows,
and held his thumb near the end of it, ready to stop up the hole.
"Now, Nathan, you may take hold of the handles, and pull them apart as
if you were going to blow."
Nathan did so. He pulled the handles apart, and held them open.
"Now," said Jonas, "I will stop up the nose, and the valve will close
itself; and then you will find that you cannot bring the sides together
again."
So Jonas put his thumb over the hole, and told Nathan to blow.
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?