i8 ROCK GARDENING FOR AMATEURS 



that cooling has taken place they have a more or less 

 glassy or vitreous appearance. Whinstone and granite are 

 typical representatives of this great class of volcanic 

 rock, and the crystalline forms obtained in certain 

 localities are also of similar nature. In the latter a 

 kind of stratification is traceable, but this is easily seen 

 to be entirely different from that of the sedimentary 

 rocks, and an attempt to break up specimens of the 

 two kinds conclusively determines their classification. 



Crystalline rocks are distinctly beautiful as specimens 

 for a museum, or a private collection, but by all means 

 should be avoided for the rockery. Gaudy, bright 

 rocks are much too conspicuous, and detract from the 

 charm of the rock garden. Weather-beaten stones from 

 which all suspicion of newness has been removed by long 

 exposure are best ; and irregular, uneven pieces of all 

 dimensions are much to be desired. 

 Avoid building with stones of uniform 

 size ; small stones are useful 

 for mixing with the soil and 

 binding the bigger pieces 

 together, but fairly large 

 ones, from a cube of six- 

 inch size up to the largest 

 obtainable, are 

 best for the 

 actual building, 



Showing the wrong use of cement in building and should be 

 up a " rock " ; all the crevices are blocked, 

 thus preventing the roots reaching the soil. Selected. 



