46 
THE FLORIST. 
saxatile, and s. variegatum. A portion, at least, of the rockwork must in 
all cases, where anything like a general collection of plants is to 
be grown, be well exposed to the sun; for unless such is the case many 
of the above plants will be quite useless. Portions of rockwork 
completely shut out from the sun may become, to many, the most 
interesting, by planting our native and other hardy Ferns. The 
common species are procurable in most localities, and the more rare are 
supplied by most nurserymen. 
0. P. 
CONSTRUCTION OF FRUIT HOUSES. 
A correspondent, “ G. P. S.,” in our last number, writing on the 
retarding of Grapes, suggests low ridge-and-furrow roofed houses, as 
the most economical for growing Grapes in quantities. 
We are strongly inclined to think that our correspondent is right, 
and that the whole question of glass erections for forcing purposes wants 
to be reconsidered. That square areas of ground covered by blocks of 
houses with ridge-and-furrow roofs, can be constructed more cheaply than 
the same area covered with lean-to, or even simple span-roofed houses, 
we think there will be no difficulty in proving. In treating this subject 
we shall employ the term block -houses as intended to define one or 
more houses built on the same plan, with upright sides, partly glazed, 
and ridge-and-furrow roofs, in contradistinction to ranges or lean-to 
houses ; and that fruit-house may be considered as comprising every 
description of house devoted to fruit culture. 
In the construction of fruit-houses there are principles involved, 
connected with the economy of vegetation, which must not be over¬ 
looked in our desire to effect a change in construction. First, the 
admission of light must have precedence, as of primary importance ; 
without a due share of light, fruit-growing under glass cannot be suc¬ 
cessful, and in close connection with this the question of ventilation 
should be considered. The means for the escape of over-heated, and 
the admission of fresh air must be ample, and sufficiently under control 
to be acted on at once and simultaneously when wanted, on which two 
points we hope to show, in a succeeding number, that both light and 
ventilation can be secured equal to what is obtained in ordinary shaped 
lean-to houses. We may next consider the application of a medium 
for conducting heat to warm the houses, and on this point, taking 
hot-water pipes as the simplest and most convenient system, the 
advantage is greatly in favour of the block system, as compared with 
the same area to be heated in houses placed in a range. 
If the advantages are conceded to the block on the three points of 
light, ventilation, and heating, we think, in reference to the question of 
borders for the trees to grow in, we are safe, as these will all (or in 
greater part) be under the roof, and therefore so far secure from rain 
and snow, which during the autumn and winter saturate outside 
borders, chilling the earth, and rendering it too cold and wet for the 
roots of many of our best fruits to grow in in this climate. Whether 
