"Now think again. We catch water as it flows from the faucet. Could teacher have caught the gas in a pail as it flowed from the burner? No, it would be impossible to catch the gas, because gases always spread themselves out rapidly in all directions. Teacher says gases differ from liquids in having no surface.""Oh yes," said Norah, "and liquids always keep a level surface."SUMMARY
Gases are fluids-they flow. Liquids always keep a level surface, but gases have no surface. They spread themselves out in all directions.
Lesson 31
The Frog-Its Life History
"Suppose my frog could talk, Norah, would you like him to tell you his history?""I should like it very much," said Norah.
"Then just shut your eyes and imagine me to be the frog. Listen to my story.
""I have not much to thank my mother for. The first thing I remember was that I was a tiny thing, with a big head and a long, flat, waving tail. I found myself swimming about in the water. I had just come out of an egg, which my mother had laid in the water. In fact, that"s all I know about my mother, for, as I told you, I never had a mother"s care. People called me a tadpole.
