THE EARTH 25 



QUESTIONS 



1. Why do we see no stars in the day time? How may 

 planets be distinguished from true stars? 



2. What planets are visible to the naked eye? What planets 

 have no satellites? 



3. How often does Halley's Comet make its appearance? 

 When did it last appear ? 



4. Name two constellations that are visible on any clear night 

 in the northern hemisphere. Why is the Pole Star so called? 



5. How many rotations does the earth make while the moon 

 is making one? 



6. Does the moon have day and night? What is the length 

 of a " day " on the moon? 



7. What simple proofs are there that the earth is round? 



8. What proportion of the earth's diameter is the height of 

 the highest mountain? 



9. If a man left Havana, Cuba, about June twenty-first and 

 traveled slowly to Rio Janeiro, reaching there about December 

 twenty-first, what changes of season would he experience? 



10. What part of the earth's surface is illuminated by the sun 

 at one time? Why does the lighted space move to the westward? 

 How many degrees per hour does it move? 



11. If the sun rises at 7 A.M. at places on the 75th meridian 

 west longitude, at what meridian will it rise an hour later ? 



12. When it is eight o'clock at Philadelphia, what time is it in 

 St. Louis? Pittsburg? Los Angeles? Detroit? Cleveland? 



