XIV INTRODUCTION. 



rocks, not as quarrymen or miners, but as farmers and 

 gardeners. From the rocks come all the soils. Thus 

 it is true the world is a great stone picture-book, and 

 he or she who has eyes to see can learn to read its 

 wonderful pages. We cannot leave the book, as long 

 as we live ; we walk over its pages every day, and this 

 ought to make us eager to understand it. It is a book 

 full of wonders, full of strange and curious things ; 

 and, while men have been reading this book of the 

 world for thousands of years, they have never found 

 the end of the delightful story. 



