ANSWERS 



TO THE PRACTICAL QUESTIONS 



IN THE 



FOURTEEN WEEKS COURSE 



IN 



DESCRIPTIVE ASTRONOMY. 



: . Did Tycho Brake have a telescope f 

 No. Galileo invented the telescope. 



2. Suppose one should watch the sky, on a winter's evening, 

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

 would he see ? 



All that is ever seen in his latitude. 



3. How do we find what proportion of the sun's heal 

 reaches the earth ? 



Calculate the surface of a sphere whose radius is the dis- 

 tance of the earth from the sun, and then estimate what pro- 

 portion of that area the earth occupies. 



4. How many real motions has the sun ? 



Two. One around its axis, and one with the solar system 

 around (he Pleiades. 



5. How many apparent motions has the sun ? 



Three.. One along the ecliptic, its yearly motion; one 

 through the heavens, its daily motion ; and one N. and S. 



6. How many real motions has the earth ? 



Three. One on its axis ; one around the sun ; an<i i *h ; rd 

 its "wabbling motion," which causes Precession. 



