"Don"t forget that evaporation goes on over every part of its surface. Of course it is more rapid in the hot parts of the world than in the cold, but even in the cold regions there is evaporation.""Teacher gave me a surprise, Fred, about the plants," said Will.
"Yes, Will, I think most of the boys were surprised to see that bottle," replied Fred.
"What was that?" asked Norah.
"Teacher showed us a bottle with some fresh- cut leaves in it. He had put the leaves into the bottle and corked it up tight before he left home for school. The bottle was perfectly dry when he put the leaves in, but when he showed it to us the whole of the inside was covered with little drops of moisture.""Then, of course," said Norah, "the moisture must have come from the leaves.""Yes," replied Fred. "Teacher says all plants give out moisture, and this moisture is changed into vapor and absorbed by the air.
"Think what a quantity of vapor must be formedand sent into the air in this way by all the trees and plants that grow on the earth.
