viii ATMOSPHERIC PRESSURE AND BOYLE'S LAW 117 



9. If you ascended to the height of 3.1 miles in a balloon, carrying 

 a liuroinrtrr, slate 



(a) The indication which would be given by the barometer. 

 (l>) Your explanation of this. 



10. State Boyle's Law. Describe an experiment which demon- 

 strates the truth of the law. 



11. What volume would the quantity of air which fills a space of 

 a cubic foot at the sea-level occupy if carried to a height of 3 A miles ? 

 Explain this alteration in volume. 



12. What would be the effect on the height of the mercury 

 column if an ordinary barometer were carried down a deep 

 mine ? 



