INTRODUCTION. 
Sandstone, if not too friable, is good, but bald; retentive of 
moisture and not sterile. Its bare lines, however, make it an 
unsympathetic building medium where better can be had. 
Whinstone and millstone have the porosity of typical sand- 
stone, with the same fault of obstinate brutality of line. They 
never adapt themselves to the plant or their builder, never cease, 
even after years of weathering, to seem crude and raw and arti- 
ficial. Each block keeps a cold and barbarous isolation of its 
own, no matter how copiously clothed in plants; and perpetu- 
ally refuses to join hands with its neighbour in a dignified and 
immemorial-looking scheme. For the triumphant achievement 
of such a scheme, however, the rock-gardener will always and 
only seek for limestone. 
All limestone, except the most friable and crumbling (such 
as some Oolites), is unparalleled in value for rock-work. By far 
the best of its forms, though, is the wonderful weather-worn rock 
of the Craven Highlands (N. Wales, Derbyshire, Westmoreland 
also), which has so singular a beauty, alike of colour and outline, 
that a rock-garden so built is well furnished in itself already, though 
never a plant has yet been inserted. (An instance of perfect 
beauty in this medium will be fresh in the minds of all those who 
saw Mr. Wood’s exhibits at the London Shows in 1912 and 1913 
—true works of art that they were, among innumerable compila- 
tions of nurserymen.) Further, it forms naturally into flutings 
and ribbings, bays and inlets, “ moutonnements ” and ripples of 
primeval effect, enhancing with lights and shadows the tender 
grey-whiteness of the stone itself, in texture soft and tender to 
the plants it nourishes so well, yet leonine and stark in its 
moulded forms, which have the rare gift of so obvious a soli- 
darity, that block fits to block like the sections of a jigsaw 
puzzle, so that the merest child at work with these could 
hardly help compiling, without thought or effort, a rock-work 
that shall really look all of a piece, the creation not of man, 
but of the untrammelled forces of the world at work since the 
hills first were. 
Thus our ground is dug, our soils prepared, our rock chosen. 
ExXxX 
