Rollo's Philosophy. [Air]

he spring. The first day, they amused themselves pretty well, during their play hours, in the shed and in the garret; but on the second day, they began to be tired. Nathan came two or

sit down by her, and she would tell them something more a

different and hesitating manner, which showed that he

very well about th

me books, and began to read; but somehow or other, they did not find the books very interesting, and Rollo, after reading a little while, put down his book, an

ecision enough to set themselves about something useful, and in fact I ought not t

aloud to Rol

box. Open this box, and you will find it filled with feathers. Select from these feathers

they for?"

ed his mother, "when you

thers. They carried them to their mother. She said that they wou

began to cut off some of the lighte

ng to give you some writ

g?" sai

plain to you something about the air, and

t write," s

tell Rollo what you would wish to

, "I don't think that tha

for play. It will be quite hard work. I hope you w

form some experiments for you, before

ether in a little heap. Then she took a fine thread, and tied this little tuft of down

member what your father told you, the oth

it light,"

make it light?"

xactly recollec

ity of air spreads over a greater space; and this makes it lighte

ool and heavy air around presses in under it, and buoys it up. This produces currents of

Rollo, "I

ut to various places, and hold it up by its thread, and it will show you the way the air

n, let us go. First we will hold

r, in such a way, that the tuft was exactly before the

ows out. The air is coming

room, and none in the entry, then the cold air in the

her," said Rollo; "it b

, "just as the water did from the hole in your dam. And, now

heir father had showed them before, that the heavy, cold air, pr

"that the cold air could come in through the

athan thought th

here it comes in. For it is plain, you see, that the light air cannot be driven up c

They found currents coming in around the windows, and by the hinges of the doors; and at length Rollo said, he meant to open the window a little way, and see if the col

m; and of course the hot air could not be buoyed up into the chimney, and a great deal of the hot air and smok

s opened wide; then should not you think that more cold an

great deal mor

" said h

air was pressing in very strongly through the open space. Wherever he held it, it was

there is cold air coming in; but I don't believe

pt the chimney and the door, and the little crevices, which he had obser

of the door-way. He did so, and found that the current of air

a little higher,

nd that it was still pre

" said h

ch a length, that the tuft hung about opposite to his shoulder.

t point, where the weight and pressure of the air above it are the greatest; j

lo, "it is very

, and if you look up chimney, you will see that there is scarcely room

"and stand up upon it, and so hold your

kept there to stand upon, in order to reach the high shelves. Rollo brought out the step-ladder, and placed it in the door-way, and then ascended it. From the t

" said Rollo,

ted Nathan,

instead of swinging into the room,

ere the hot air of the room goes to, to make roo

to the entry

ere to open the door, you see that the water, being heavier, would flow in, through the lower part of the door-way, into the parlor, and the air from the parlor would flow out, through the upper part of

ther," s

open the door, then the cold air, being heavier, will sink down, and spread over the floor of both rooms; and the warm air, being light, wil

her, "let me recapitulat

by recapitulatin

ance of it, so that you

now," said Rollo; "

er it, Nathan?"

emember some of

llo kept his desk, and they remained there half an hour.

the largest paper, a

t the window, and it blew in very strong. At the bottom of the door, it blew in very strong too; but at the top, it blew out, into the entry. S

ll

o in Rollo's handwritin

ht, and you were to open the door between the two rooms, the water would flow into the pa

th

STI

repare the downy tuft? What experiments did they perform with it? Where did they find that the air came in which crowded the warm air up the chimney? What experiments did they perform when the door was opened? Which way di

to co