Mr James Bewley’s Description of a Plant-house. 241 
irregular rockwork about 10 feet high, with concealed steps 
to the top, and from these a path from side to side to enable 
a view to be had of the plants below, there being a number 
of tree ferns standing on the floor. This path is depressed 
so as to allow a person to pass under the lowest part of the 
roof. On the north side of the path, the rockwork is car- 
ried up to the top of the house, so that when viewed from 
below, the rockwork is seen to extend from the ground to 
the glass. An irregular rockwork is also carried round the 
south end, and along the east and west sides, up to the 
glass (7 feet) ; but it is separated from the outer walls by 
a space of 6 inches to allow ventilation from the outside, 
and also for the circulation of heat, from a pair of 4-inch 
water-pipes which run round the house. This is the only 
heating power. In order to promote a circulation of air, 
there are openings, in fact small concealed arches in the 
rockwork, on the ground level, passing through it to the 
narrow space next to the outer wall. Thus the hot-water 
pipes being next to the outer walls, and there being venti- 
lators in these, and openings on the ground level inside, 
through the rockwork, there is a perfect circulation of air 
maintained—a matter all important to the health of plants. 
The roof is one of ordinary construction ; wooden rafters 
4 feet apart, with three light iron sash bars between. (1 
may here remark, I prefer the combination of wood and 
iron to either exclusively. All iron has too uniform an 
appearance to please me. Wooden rafters 4, 5, or 6 feet 
apart break the dull uniformity into spaces, and are of 
great practical convenience, by enabling a nail, screw, or 
hook to be put in whenever wanted.) The inner glass is 
common 21 oz.; it is put in about 7 inches on the wnder side 
of the rafter ; so that, the rafter being about 6 inches in 
depth, 5 inches of it are outside. Now, on these rafters 
the outer roof rests—simple framed sashes, 4 feet wide,— 
and for the convenience of moving, in two lengths. They 
are glazed with the same glass as the sides, and are fixed 
in their places by a screw bolt, so as to be removed when 
required. Thus the inner and outer glass are from 5 to 6 
inches apart. I do not think the distance is important; 
anything from 4 to 6 inches will do; but what is all im- 
