'j'j() Home Nature-Study Course. 



disc of the moon faintly outlined within the new crescent it is because the light 

 reflected from our earth illumines it sufficiently so that we can see it. It is difficult 

 sometimes for the pupils to understand the difference between this old moon in 

 the new moon's arms and a partial eclipse, but the former is one edge of the moon 

 shining in the sunlight and the remainder illumined faintly by the earth light, while 

 an eclipse must always occur near the full of the moon when the earth gets between 

 the sun and the moon and hides the latter in its shadow. The moon keeps one face 

 toward the earth because practically, as one might say, it revolves around the earth's 

 axis instead of an axis of its own. It is, of course, approximately a month 

 from one new moon to the next, and the children should find this by studying 

 the almanac or making observations. As it takes twenty-nine and one-half days 

 for the moon to make one revolution, therefore, each moon day is fourteen and 

 three-fourths days long and the night the same length. Of course, the pupils will 

 find for themselves that the moon goes around the earth once each month. The 

 explanation of the difference in time between the sidereal and lunar months is too 

 advanced for these lessons, — as is also the subject of the moon's effect upon 

 our tides. 



Lesson XXIV. 



THE PHYSICAL GEOGRAPHY OF THE MOON. 



Purpose. — To make the pupils think what air and water do for the 

 world. 



Questions for the pupils to think about and anszver if they can. — 

 (i). Since it has been proven that there is no air or water on the moon, 

 could there be any life there? 



(2). Supposing you could do without air or water and should be able 

 to visit the moon, what would you find to be the color of the sky there? 



(3). Would there be a red glow before sunrise or beautiful colors at 

 sunset? 



(4). Would the sun appear to have rays? 



(5). Could you look at the sun without being blinded? 



(6). Would the stars appear to twinkle? 



(7). Could you see the stars in the daytime? 



(8). How would the shadows look? If you could step into the shadow 

 of a rock at mid-day, could you be seen? 



(9). Could you tell by looking at it whether a mountain was far or 

 near? 



(10). It is estimated that the temperature of outer space is 250 

 degrees below zero, and the sun's direct heat is 500 degrees above zero. 

 Supposing this be correct, how hot would it be in the sunshine on the 

 moon ? 



(11). How cold would it be at midnight? 



