186 LABORATORY LESSONS IN GENERAL SCIENCE 



This record should be made at intervals of two or three days through- 

 out a month. If the weather has been unfavorable, continue the ob- 

 servations for two months or more. Observe the moon's appearance 

 as early in the morning, too, as possible. 



1. On your paper make a drawing to show the shape of 

 the moon as you saw it last. At what hour and date was 

 this? 



2. Hold at arm's length an orange from which the peel 

 has been removed. With the same side toward you all the 

 time, 1 turn completely around where you stand without 

 stepping to one side. Let the revolution of the moon about 

 the earth be thus represented in the motion of the orange 

 around yourself as an observer. 



Select some object in the room as a source of illumination 

 (the sun). Using the shell of a half orange to cover the 

 unilluminated side of the peeled orange (always, of course, 

 on the side opposite the light), note very definitely the form 

 of the white (illuminated) part visible to you as seen under 

 these several conditions : 



(a) When the orange is held between the eye and the 

 object representing the sun. 



(6) When it is moving through the first quarter of its 

 circular path. 



(c) At the end of this quarter. 



(d) When moving through the second quarter. 



(e) At the end of the second quarter, and opposite the 

 sun. 



(/) When moving through the third quarter. 

 (g) At the end of the third quarte*r. 



1 One side of the moon is always away from the earth, and a large part 

 of that side is never visible from any part of the earth at any time. 



