e edge.

"What lots are cracked!" said Tommy. "Oh! August, here is one cracked all
round."

"Yes," said August, "that chick will soon be out." Even as he spoke the
shell parted, and a third little bright-eyed chicken struggled out and
looked about in amazement.

The children could have watched them much longer with great interest, but
mamma was afraid the incubator would get too cool, and she advised August
to cover it.

"How _do_ they do it, mamma?" asked Katie.

[Illustration: HOW THE CHICKEN IS PACKED.]

"The little chick is packed very wonderfully in his shell," said mamma.
"His head under his wing, legs folded up with the feet toward the head,
his bill coming out from under one wing. This bill is furnished with a
little hard point on the top. When he is ready to crack the shell and
come out, he begins to move. He turns his whole body slowly round,
cracking the shell as he goes, by pressing with his whole force against
it, the hard, sharp point on the top of his bill coming next the shell.
When he is a few days old this hard point drops off. Just before he
hatches, after the egg is cracked all around, he frees his head from his
wing and struggles to stretch himself. Then the shell parts and he gets
his head out, and presently his legs, one after the other. I forgot to
say that just before hatching he gradually absorbs the yolk of the egg
into his body, and that nourishes him for twenty-four hours after
hatching."

[Illustration: HOW THE SHELL IS CRACKED.]

"It's very curious, isn't it?" said Tommy.

"I didn't know anything but hens or ducks could hatch eggs," said Katie.

"Why, Katie!" exclaimed August, "there is a place at Canton, in China,
where _thousands_ of ducks' eggs are hatched artificially every day.
There are twenty-eight rooms to the establishment, and all along the
sides of these rooms are rows of sliding trays filled with eggs. These
eggs are put in the first room the first day; on the second day they are
moved to the second room; and so on, until they hatch in the last room.
The heat is graduated, the last rooms being cooler than the first. All
these eggs are hatched by the heat of the rooms."

"If they hatch thousands every day," asked Tommy, "what do they do with
the little ducks?"

"They hatch them for the people in the neighboring towns," replied
August. "The Chinese are very fond of ducks and ducks' eggs. A gentleman
who has been to Canton, and seen the hatching-rooms, told me he ha