Water feeds the growing plants by dissolving proper food for them out of the soil. Water dissolves many substances out of the earth as it soaks through. It forms mineral springs and brine springs, but all this water falls in rain from the clouds at ?rst.
Lesson 08
Birds
"Suppose we have a chat about birds this evening," said Fred. "Can you tell me, Norah, why all birds are clothed with feathers?""Feathers make the lightest of all coats," said Norah. "Birds have to raise themselves in the air and fly, and a thick heavy coat would prevent them from doing this.""Quite right, and so would a thick heavy body, wouldn"t it? Teacher has been showing us that the bird"s body must be light as well as its clothing.
"If we compare the bones of a bird with the bones of some other animal about the same size, we find a great difference. The bones of the bird are very much lighter.
"You would find out the difference by holding Will"s guinea pig in one hand and my pigeon in the other. I am sure it would surprise you.
"The bones of the bird are all hollow, and at the same time they are very light and thin.
"Now let us think of the build of the bird"s body.
