124 ANSWERS TO PRACTICAL QUESTIONS 



27. lit, Greenland, at what part of the year will the 

 midnight sun be seen due north ? 



At all places whose latitude is 66 30' N., the sun will be 

 on the northern horizon at midnight of the summer solstice. 

 At all places north of the Arctic Circle the sun will remain 

 above the horizon, even at midnight, for a certain portion of 

 the summer, the number of days increasing with the latitude. 

 Read Ball's Elements of Astronomy, p. 142. 



28. Can you give any other proof of the rotundity of 

 the earth 9 besides that named in the teoct (p. 85) ? 



(See Astronomy, note, p. 299.) 



A sphere is the only body that always presents to us the 

 form of a circle, no matter in what direction we view it. At 

 sea, the circular form of the horizon is even more evident than 

 on land. 



29. Point out the error in tJie following passage from 

 Byron's "Darkness," where the poet, in describing the 

 effect of tJie sun's destruction, says : 



" I had a dream, . . . 



. . . which, was not all a dream ; 

 The bright sun was extinguished, and the stars 

 Did wander darkling in the external space 

 Eayless and pathless." 



The fixed stars would be unaffected by the extinction of the 

 sun's light. 



30. Explain the rernarh of the First Carrier in Scene 

 I., Act II., King Henry IV. : "An't be not four by the day, 

 I'll be hanged: Charles' wain is over the new chimney." 



(See Astronomy, note, p. 311.) 



Since the two great stars which mark the summit and the 

 foot of the Cross have nearly the same right ascension, it fol- 

 lows that the constellation is almost perpendicular at the mo- 

 ment when it passes the meridian. This circumstance is known 

 to every nation that lives beyond the tropics or in the Southern 

 Hemisphere. It has been observed at what hour of the night, 

 in different seasons, the Cross of the south is erect or inclined. 

 It is a time-piece that advances very regularly near four min- 



