HEAT OF THE SUN.
ILLUSTRATING DAY AND NIGHT.
"We live on a big round globe called Earth," replied his sister, "and we travel round the sun, which gives the earth light and heat. The sun is like a great lamp in the sky, and when you face the lamp you see the light, but if you turn away from it you are in darkness. As the earth goes around the sun, it whirls around like a huge top; first one side and then the other is turned to the sun and gets sunlight, and so we have day and night. If the sun, or the lamp in the sky, went out and stopped shining, all the light would go out on the earth, and we would miss its heat as well.
"It is so hot that if it kept coming nearer and nearer until it was as far from the earth as the pretty bright moon, the earth would get warmer and warmer and melt like a ball of wax."
"Just like Nellie's doll, then," said Harry, "when she left it on the grass the other day. The sun was so hot that day that when Nellie picked up her doll, she found that its wax face had melted and the eyes had fallen in. So the sun did that," continued Harry, laughing heartily. "Poor Nellie! I must tell her that the next time I see her."
"I can show you something else to prove how hot the sun is," said Mary, as she picked up a leaf from the ground. "Just wait a moment while I go into the house and get a magnifying-glass."
In a few minutes she returned, holding the glass in one hand and the leaf in the other. She held it so that the sun shone directly upon the glass and passed through it onto the leaf. In a few seconds the leaf began to smoke, and then burn, until a little hole could be seen.
Harry was so surprised that he had to try it for himself, and he looked forward with much delight to a visit from his cousin Nellie.
"Won't I have a lot to tell her?" he said to his sister: "all about the sun's melting her dollie, and how to make the sun burn a hole through a leaf. But the sun cannot be very far away, can it?" he asked.