CONSERVATIVE WALLS. 61 
the view of relieving their^ nakedness. The consequence has been, that besides 
being without the means of heating them, they have two prominent defects which 
we consider very objectionable in an ornamental garden. The first is, that they are 
destitute of all architectural beauty in themselves, and do not exhibit the plants 
properly ; and the other consists in the absence of trellises for tying the plants to, 
on which account a slovenly aspect is almost inevitable, for shreds and nails, and 
the numberless crevices which the latter occasion, are very unsightly on a wall to 
which flowering climbers are trained. 
What seems to us necessary to impart a suitable character to an ornamental 
wall, is the occurrence of more prominent parts at certain intervals, or the division 
of the whole into recesses 'and projections. The latter, by being of limited dimensions, 
will serve for the display of the more hardy kinds of plants, and also give some 
degree' of shelter to the remaining portions. If, moreover, the whole be surmounted 
by an appropriate coping, its beauty will be greatly enhanced. 
Much has been said of the conservative wall at Chatsworth, the leading 
characteristics of which are a practical illustration of the opinions now advanced,— 
large retiring compartments, covered with a neat trellis, and relieved by occasional 
small stone projections or piers ; and as the wall stands on a steep slope, each of the 
piers is raised considerably higher than the one below it, thus constituting, as it 
were, a series of very broad ascending steps on the top. 
The advantage of having a slight wooden trellis against the wall, .instead of 
fastening the plants to it in the usual way, need scarcely be pointed out. Independ- 
ently of its superior appearance, which is a point too frequently neglected in such 
matters, the greater ease with which the branches can be attached to it, and removed 
or altered at any time, is quite sufficient to give it the preference ; while the 
destruction and defacement of the wall consequent on the use of nails, and the 
injury they often occasion to the shoots of the plants, give a value to any system 
by which they can be discarded. The extra expense of the trellis is too trifling 
to be regarded. 
Since the attempt to grow tender exotics against open walls was first made, a 
* fact of considerable moment has been developed relative to their protection. It has 
been found that whatever tends to preserve the border in which they are planted com- 
paratively dry through the winter months, does more towards sheltering them from 
the injurious influence of frost than extensive protection of another kind which does 
not include that provision. This is accordant with the truest philosophical theories, 
and is capable of application to many instances beyond that immediately in question. 
It proves that as most of the fluids of plants are imbibed through the roots, and as 
the heat of vegetable bodies escapes mainly in proportion to the fluids they contain, 
protection to the medium in which those roots are growing is certainly not less, and 
possibly even more, needful than to the stems and branches. 
In applying such a principle to plants trained to conservative walls, it will 
readily be seen that some sort of covering is requisite which will embrace at least 
