8 Unsuitable Rocks 



ferred because of its high decorative value, though 

 from the point of utility I know of no useful purpose it 

 may serve that could not be served by the carbonifer- 

 ous limestones, e.g., the famous Millstone Grit. It 

 scores chiefly by reason of decorative effect, and in this 

 sense tufa is probably unique. Highly fossilised rocks, 

 as those belonging to the Gryphsea and Ostrea group 

 of the Cotswolds, and others which in Nature have be- 

 come crystallised by contact with rocks in the molten 

 state, I regard as unsuitable for rock gardening in 

 general. The first-named attract too much to them- 

 selves, and are otherwise too thin for effective work. 

 In their own district they are frequently used, though 

 they are mostly in demand for the dry stone wall fence 

 so characteristic of the Cotswold region. 



Granite Rook.— This is the last of the natural rocks 

 of this country calling for remark here, and it is, in my 

 opinion, the least valuable, primarily because of its 

 nature — hard, impervious and non-absorbent — which 

 is known to all. Hence it is at once, broadly speaking, 

 unsympathetic to plant life, and, therefore, unsuited to 

 the purpose we have in view. It has, however, the 

 merit of cheapness, with a boldness and ruggedness 

 which surpasses all others perhaips, and, of course, 

 everlasting wear. In these respects it is, without ques- 

 tion, unapproachable, and those whose idea of rock 

 gardening consists in the piling up of huge boulders 

 alone may find in granite something after their heart's 

 desire. The object in view, however, is rock building 

 in conjunction with alpine gardening, and while Nature 

 through the centuries had adorned the granitic rock 

 fissures or recesses with more or less luxuriant vegeta- 

 tion, the instances of such in gardens are exceedingly 

 rare. In granite, too, the nourishing quality of the 

 limestones is entirely lacking, hence our low estimate 

 of its worth when we are gardening in conjunction 

 therewith. 



Artlfioial Rooks — In the opening lines of this chap- 

 ter these were referred to as "almost all wholly bad," 



