align="left">The Mammoth Cave of Kentucky
114 |
| Land Building by Rivers |
121 |
| The Making of Mountains |
126 |
| The Lava Flood of the Northwest |
130 |
| The First Living Things |
134 |
| An Ancient Beach at Ebb Tide |
138 |
| The Lime Rocks |
147 |
| The Age of Fishes |
152 |
| King Coal |
155 |
| How Coal Was Made |
160 |
| The Most Useful Metal |
167 |
| The Age of Reptiles |
175 |
| The Age of Mammals |
180 |
| The Horse and His Ancestors |
186 |
| The Age of Man |
194 |
| PART II. THE SKY |
| Every Family a "Star Club" |
201 |
| The Dippers and the Pole Star |
207 |
| Constellations You Can Always See |
213 |
| Winter Constellations |
219 |
| Orion, His Dogs, and the Bull |
223 |
| Seven Famous Constellations |
231 |
| The Twenty Brightest Stars |
239 |
| How to Learn More |
241 |
ILLUSTRATIONS
| Pike's Peak |
Frontispiece |
|
FACING PAGE |
| Sand Dunes in Arizona |
44 |
| Grand Cañon of the Colorado |
45 |
| Castles Carved by Rain and Wind |
52 |
| Where All the Water Comes From |
53 |
| The Richest Gold and Silver Mines |
72 |
| Rocks Being Ground to Flour |
73 |
| A Pond Made by a Glacier |
|
