136 A YEAR IN SCIENCE 



6. How high will the atmosphere hold a column 

 of water? Of mercury? How do you account for the 

 difference in these heights? 



7. Does the height of the column of mercury held 

 by the atmosphere vary with the diameter of the tube ? 



8. How can you prove that air presses in all 

 directions ? 



9. Does the pressure of the atmosphere vary? If 

 so, under what conditions? 



10. What is the structure of a barometer? 



11. Why do we use mercury in a barometer instead 

 of some other liquids? 



12. What are the uses of a barometer? 



13. What kind of weather does a high barometer 

 indicate? A low one? 



