IN DESCRIPTIVE ASTRONOMY. 123 



One going around the world westward will lose a day in 

 his reckoning ; one going eastward will gain a day. The Alaska 

 calendar was established by those who came from the West to 

 this continent, and their Tuesday corresponded to our Monday. 



20. Why do the dates of the solstices and equinoxes 

 vary a day in different years ? 



(See Astronomy, p. 99.) 



Leap-year advances the dates one day. 



21. Why are not forenoon and afternoon of the same 

 day, as given in the almanac, of equal length ? 



(See Astronomy, p. 265.) 



Apparent noon marks the middle of the day ; but mean 

 noon may be either before or after the apparent noon; i.e., 

 the time when the real sun is on the meridian. 



22. In ivhat part of the heavens (in our latitude) do 

 the stars apparently move from west to east? 



The northern circumpolar constellations revolve about the 

 North Pole, and, during a part of their paths, they apparently 

 move from west to east. 



23. What year was only nine months and sioc days 



long ? 



(See Astronomy, note, p. 312.) 



24. What day ivill be the last day of the nineteenth 

 century ? 



December 31, 1900. 



25. If one should watch the sky, on a winter's evening, 

 from 6 P.M. to 6 A.M., ivhat portion of the celestial 

 sphere would he be able to see ? 



All that is ever seen in his latitude. 



26. How do ive know that the moon has little, if any, 

 atmosphere ? 



Because when the moon occults a star, there is no refrac- 

 tion of the star's true place. 



