THE TYPES OF ROCK GARDEN 23 



The large hollow is not a form which re- 

 commends itself very much, for it is apt to 

 look too artificial and also entails considerable 

 labour to make. But in cases where there is 

 only a very limited extent of ground it is useful, 

 for in this form the maximum amount of 

 surface available for planting can be obtained. 

 It must be on sloping ground, for to dig a 

 large hollow in the level will usually result 

 in the formation of a small lake. The lower 

 side should be open and at least level with the 

 surrounding ground, above it if possible. This 

 entrance should face either east or south ; the 

 north is the least desirable aspect, because 

 then so little of the garden would get any sun. 



The gravel-pit is practically identical with 

 the foregoing, except that the hollow is already 

 made. The lie of the ground here must also be 

 such as to ensure the drainage being efficacious, 

 and the open side should face any point except 

 the north, preferably south or east. 



The bank and \noll types are exactly the 

 same as the rocky bank and rocky knoll 

 already described, except that in the former 

 the natural rock is already there, while in the 



