168 
PRIMARY GEOGRAFHY, 
LESSON 80. 
PLANETS, 
i. THERE are two kinds of stars to be seen in the heavens;— the 
planets and the fixed stars, The first are called moving, or wander- 
ing stars, because they alter their positions in the sky. 
2. The planets are opaque bodies, and have no light oftheir own, 
but shine by reflecting the light of the sun, around which they move, 
or revolve. Some of them are many hundred times larger than the 
earth; but otbers are of less size. 
Commnarative size 0° „he Planets. 
This picture shows that the earth is much smaller than Jupiter, 
Saturn, and Uranus. The planets Venus, Mars, Mercury, and the 
Moon, are still smaller, . 
3. The planets all appear to be spherical bodies; that is, they are 
round, like a ball, or an apple. Each of them, by turning constantly 
on its own axis, has a regular succession of day and night. 
4. The varied appearance which the surface of the planets presents, 
when examined by powerful telescopes, shows that some parts are 
high, and some are low ; some are bright, and others are dark. The 
bright parts are supposed to be land, and the dark parts water. 
Questrons, — 1. How many, and what kinds of stars are there in the heavens? 
.— What do they form a part of? 2. What are tbe planets ? — How’ do they 
phine? — What are some of the planets? 3. How do the planets appear? 
4. What are the bright and dark parts of the planets supposed to be? 5. How