CHAPTER II 

 THE WORLD IN THE MAKING 



]HE world passed through a long period 

 of development before there were any 

 oceans or rivers or atmosphere upon it to 

 serve as agents of erosion or deposition. 

 The earth on which we live is one of 

 several similar bodies called planets that 

 move about the sun. These planets, in 

 order from the sun outward, are Mercury, 

 Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. 

 Around many of these planets as centers there are other smaller 

 bodies known as moons. The earth has one attendant moon, 

 Jupiter four, Saturn ten. Planets and moons appear bright when 

 seen from the earth, shining by the reflected light of the sun. The 

 planets look like stars to the naked eye ; the ones near our earth are 

 very bright and are familiar as evening and morning stars. Our 

 sun, on the other hand, shines because its substance is so intensely 

 hot that it is perpetually emitting light. It is a true star and not a 

 very large one either, but it is so near our earth, comparatively 

 speaking, that its light and heat seem much greater to us than that 

 of much larger suns or stars that are very far away. The diam- 

 eter of one of the stars in the constellation Orion, Betelgeuse by 

 name, recently measured by a newly devised instrument, is some 

 three hundred times that of the sun. Sun and planets, moons, 

 and some still smaller bodies that revolve about the sun together 

 make up our solar system. Probably the other stars are also 

 centers of planetary systems. 



The eye unaided counts four or five thousand stars, but the 

 telescope enables us to locate hundreds of thousands, and each 

 new telescope more powerful than its predecessors adds to the 



