V 
334 ROCK-WORK. [chap. x. 
chosen, to prevent them from becoming too 
large for the rocks. The part which repre¬ 
sents the 66 Mer de Glace,” is “ worked with 
grey limestone, quartz, and spar. It has no 
cells for plants; but the spaces are filled 
up with broken fragments of white marble, 
to look like snow; and the spar is to imitate 
the glaciers.” I have already mentioned that 
Lady Boughton was her own artist; and, I 
may add, that the rock-work was six or eight 
years in progress, before it was completed. 
Whatever kind of rock-work may be 
erected, the first thing to be done is to make 
a secure foundation; as, unless this is effected, 
the stones will gradually sink into the earth 
by their own weight; and thus, in a few 
years, the mass will either have become half 
buried, or tottering and insecure. It is there¬ 
fore most prudent, unless the rock-work be 
actually erected on a solid rock, to prepare 
a foundation for it of brick-work; not suf¬ 
fering, however, any of the wall to appear 
above the surface of the ground. To prevent 
the possibility of this foundation wall being 
seen, it will be best not to carry it higher 
than to within six or eight inches of the sur- 
o 
