"Look now at my leather sucker. I make it hold to the stone, because I press out every particle of air between them. It holds because the air outside it is pressing it to the stone. If I try it on this slate, it does not matter whether I hold the slate level, place it against the wall,or sideways, the sucker will hold. The air in each case presses it against the slate.
"Now we know then that air presses with equal force upwards, downwards, sideways, and in all directions."SUMMARY
A square box, a foot across each way, holds one ounce of air. Air presses with equal force downwards, upwards, sideways, and in all directions.
Lesson 29
The Frog and the Toad Compared
"Fred, can you tell me the difference between frogs and toads?" asked Norah. "They seem to me to be so much alike that I am sure I could not tell one from the other.""I think I can make it clear to you, Norah," said Fred. "We had a good lesson about these animals this morning.