NATURE-STUDY LESSONS. 187 



From the time of full moon until half of the illuminated part is visible, 

 it is in its tAirJ quarter. 



From the time of its third quarter until new moon, it is in its !asi quarter. 



In the Nautical and other almanacs these phases are called respectively 

 the new moon, first quarter, full moon, and last quarter. 



8. What is the shape of the visible part of the moon 

 at the following times : — 



(«) While it is in the first quarter ? 

 {b) While it is in the second quarter ? 

 (c) While it is in the third quarter? 

 {d) While it is in the last quarter ? 



9. {a) Have a companion walk in a circle round you 



while you are seated in a chair as follows : — ■ 

 (i) Always having the same side to you. 

 (2) Always having his face looking in the 

 same direction. 

 (^) In the first case, what part of him can you see? 

 {c) In the second case, what part of him has been 

 seen when he has completed the circle ? 



10. (a) As the moon always presents the same side to 



us, what inference can be drawn with refer- 

 ence to the way in which it moves round 

 the earth? 

 ((5) Then how often must it turn on its axis each 

 month .' 



1 1. From what you know of the reflection of light, infer 

 whether the moon receives any light from the earth. 



1 2. Explain, if you can, why the dark portion of the 

 moon's disk is dimly visible during the first and last 

 quarters. 



