62 ELEMENTARY SCIENCE 



In this way it was found that the height of a column of 

 mercury could be used as a measure of altitude above sea- 

 level. 



QUESTIONS 



1. Explain what happens when you suck up lemonade through a 



straw. 



2. Why can't you pour liquid out of a can with only one hole in 



it? 



3. Explain how a pump works. 



4. Explain how a siphon works. 



5. Explain how an aneroid barometer works. A mercury barom- 



eter. 



6. Why is the barometer important for the "weather-man"? 



