xxiv INTRODUCTION 



rocks, and they saw that it was protected by those 

 rocks from extremes both of heat and cold, of drought 

 and moisture. They saw, too, that it could get that 

 protection only from rocks arranged in certain natural 

 ways; and therefore they set to work to imitate such 

 arrangements ia their own rock gardens. So the 

 building of rocks became an art and also one of the 

 chief pleasures of rock gardening. It is difficult to 

 convey to any one who has never tried it how great 

 that pleasure can be, and how it iacreases with experi- 

 ence. There is no one fixed principle of rock build- 

 ing, since natural arrangements of rocks are infinitely 

 diverse, and different plants have adapted them- 

 selves to their diversities. But this fact is what makes 

 the pleasure of the game. The beginner, if he is wise, 

 will build upon a fixed principle. He will arrange 

 most of his rocks so that they run into the ground at 

 an angle of about 45 deg. with the earth's surface, and 

 so protect the roots of the plants below them from 

 both heat and cold. But as his knowledge iacreases 

 he will get more of the variety of nature into his build- 

 ing, and put his rocks together so that they provide 

 homes exactly suitable for the more difficult plants 

 which he wishes to grow. He will come to look upon 

 his rockwork as a kind of puzzle to be fitted together 

 so that every interstice will have some peculiar charm 

 for some particular plant; and it will be his delight 

 to find a plant perfectly suited to each interstice. 

 Needless to say, this is not a game that can be played 

 in the ordinary flower border, where there is not much 



