THE ROCK GARDEN 
211 
Material 
Used. 
the smooth, flat lawns and flower-beds of Kew, might easily have 
created a sense of incongruity, but this was avoided by shutting out 
any view of the immediate surroundings. 
Owing to the limited amount of money available, it was not 
possible to build the rockwork from end to end — it is 270 yards long — 
with one kind of stone only, as would, of course, have been 
preferable. A quantity of finely-weathered pieces of 
Bath oolite was obtained, and also some water-worn 
limestone from the cliffs at Cheddar. At this time there existed in 
the Arboretum an old ruin, with a sort of cellar attached, known 
as the “ Stone House.” It was said to have been constructed by 
the sons of George III. A certain spurious interest had gathered 
about this overgrown ruin through its having acquired the name 
of Merlin’s Cave. (The true Merlin’s cave of the Richmond Gardens 
stood, as has been told in an earlier page, on a spot near the southern 
corner of the present Lake.) The material of which the Stone House 
was built had, in the long course of years, sunk into the ground, and 
in digging it out several fine masses of marble and Portland oolite 
were found. All this furnished useful if somewhat mixed material 
for the Rock Garden. Some of the stones had been squared for 
building purposes, and the rather happy idea was adopted of imitating 
with them uptilted stratified rocks. 
All these sources, however, did not furnish sufficient material 
for the whole length of the Rock Garden. In several places tree 
roots were employed for holding up the banks. This was 
adversely criticised at the time, but experience proved 
that, although somewhat of a makeshift, it was well 
worth doing. It enabled the whole scheme at the time to be worked 
on bigger lines, and the result has shown that very many naturally 
vigorous herbaceous plants revel in the humus formed by the de- 
caying wood. Tree-stumps, of course, perish comparatively soon, 
but they have, as occasion served, been renewed, and in parts 
have been replaced by oolite obtained from Lord Redesdale’s estate 
in Gloucestershire. 
The plants bequeathed by Mr. Joad amounted to 2,630, many 
of them choice and rare species. Although, at the time, they went 
a good way towards filling the Rock Garden, new species and varieties 
have been freely and continuously added ever since. Perhaps the 
most important genus is Saxifraga, of which there are some 200 species 
Tree 
Stumps. 
