164 THE COTTAGE GARDENER. June 10. 
tlie laths may he removed along with the covers, the 
sashes washed, and this will render the winter and its 
litter forgotten. Such pits, or rather houses, will be very 
useful in small places, and may often be fixed econo¬ 
mically where two walls meet, as then, with tire excep¬ 
tion of the glass, the chief expense would he the low 
wall in front, and the glass or opaque material for the 
end. 
2nd. “At what angle should I place my glass roof?” 
This, as I previously endeavoured to show in detail, 
must depend on what you want, and the time you want 
it; 45° combines more useful properties than, perhaps, 
any other, as it will do for early, medium, and late work. 
For very early things, the glass should approach more 
nearly to the perpendicular—say from 25° to 35°. For 
gaining the most power in summer, the angle should he 
larger—say from 50° to 65°. In other words, suppose 
the same house was used, the front wall would require 
to he raised, so that the glass would be flatter. With 
rafters put in, so as to he moveable, it would he an easy 
matter to alter the angle of a house according to what 
was expected from it. We have yet much to learn on 
this subject. We build upright brick walls for tender 
trees; nay, we are to have upright glass walls lor the 
same purpose. The fault in both is the same. The 
sun strikes most powerfully on them in early spring; 
vegetation is prematurely encouraged, only to be after¬ 
wards dangerously arrested. What if, before long, we 
should witness one of two things ! either our early best 
walls protected by glass, not upright , nor at an acute, 
but at a somewhat obtuse angle, that little heat may 
reach the wall in spring, but a great deal find its way 
to the space before it in summer; or these walls devoted 
to late-blooming plants, or used chiefly as boundaries; 
while the best fruits will be trained against obtuse, 
sloping banks, rendered hard and waterproofed, or 
nearly so, on the surface, so that they may bloom late 
in spring, and then receive a more powerful heat in 
summer than ever they could receive against an upright 
wall. 
3rd. “ But you mentioned how these six feet lights, 
instead of covering several short pits, might be more 
economically employed in covering a span-roofed house.” 
Nothing more easy. According as you sink, or do not 
sink your pit, have two side walls, each from a foot to 
throe feet above the surface. Place two rods, six feet 
in length, against each other, triangle shape, and accord¬ 
ing to the steepness and flatness of your intended roof, 
will be the width of the base line; if too flat, there will 
be drip in winter. The rafters must join each other at 
the apex. The pathway will be in the middle, with a 
bed or platform on each side. Unless you have a broad 
shelf above your head, you will lose part of the light 
from the glass in the apex. But the house might be a 
little wider, and then you might have eighteen inches of 
opaque work on each side of the apex, against which 
the sashes would abut. This would render the house 
quite as pleasant for walking in, and the uses for plant¬ 
growing would be greater, while the expense would be 
less than for pits. 
4th. “ But, now, what is the best form of bouse you 
would recommend for keeping and growing plants ? ” 
I shall tell you what I should like to do, had I the 
chance to-morrow. The length I should say nothing 
about, as I would be greedy enough to take every inch 
I could get. I would have it to stand nearly north and 
south, and from fifteen to sixteen feet wide inside mea¬ 
sure. The walls I should have three feet above the 
surface, with wooden ventilators in them; upright 
sashes, three feet in height; apex of the span roof, 
ten feet from the floor; front shelf all round, two feet 
wide; pathway, three feet all round, and a platform in 
the centre a few inches higher than the front shelves. 
R. Fish. 
CONIFERS. 
(Continued from page 129.) 
By our last paper on these fine trees we hope to have 
raised a desire amongst our readers to have some more 
information on such an interesting and important sub¬ 
ject. As there is nothing like a method and arrange¬ 
ment in such matters to make them intelligible and 
useful, we shall treat the subject under the following 
sections:—1. Planting, including soil and arrangement. 
2. An alphabetical catalogue, including height, habit, 
uses; as timber, as resin-producing trees, as food, as 
fuel, and as objects of ornament to the lawn or park. 
3. Propagation by seed, by grafting, and by cuttings. 
Planting. —Previously to planting, due consideration 
ought to be given for what object planting is undertaken. 
It has been a practice for several years, by many wealthy 
lovers of plants, to set out a plot of ground to cultivate 
one or more of all the trees hardy enough to bear the 
open air as specimens, and by such a collection to be 
able to judge of their respective merits as objects of orna¬ 
ment or use. This is a very useful and interesting 
study; but as from their great numbers this requires a 
large extent of land, and a commensurate expense, there 
are but few proprietors of estates that either have means 
or opportunity to carry it out to the fullest extent; but 
when it is done, the very appropriate name of Arbore¬ 
tum is given to such a collection. Mr. Loudon strongly 
recommended such collections being formed, and bis 
great work the Arboretum Britannicum was a text to go 
by in forming them. Such gentleman as the Duke of 
Devonshire, and a few others, had the public spirit to 
carry out bis views, but others contonted themselves with 
forming smaller collections. The Duke of Bedford paid 
great attention to the Salix family, and the Earl of 
Harrington and several others to the Pine tribe, that 
which forms our present subject This branch of an 
arboretum is happily enough named a Piuetum, or a col¬ 
lection of cone-bearing trees, of which the pines form so 
large a portion as to give it a name; the cones being 
commonly called pine or fir apples. 
A pinetum, then, we will suppose to be determined 
upon. Of course it may either be large enough to con¬ 
tain several of each species, or only to contain one or 
two, or even only to afford space for the most beautiful 
kinds. Whatever extent is determined upon, due regard 
should be given to the situation. By far the greater 
number of the tribe are found at a considerable elevation 
above the level of the sea. Some grow on the steep, 
rocky sides of mountainous regions; others grow on dry, 
level plains, whilst a few species are found to inhabit low, 
swampy grounds, not positively wet, nor even flooded 
with water. Taking all these into consideration, the 
best situation for a pinetum will be a rather elevated 
position. Rich deep soil is not necessary, for the roots 
of the greater part of the tribe do not descend deep into 
the soil, but spread out on the surface. This may be 
seen whenever one is felled by a storm. The roots will 
then be observed to have spread far and wide; hence it 
will be seen at once that ground valuable for the grow¬ 
ing of corn or farm vegetables, need not be encroached 
iqion, but some place fixed upon where little else with 
profit can be cultivated. Then, as to the space required; 
this depends entirely upon the extent the proprietor may 
please to devote to the purpose. If mere ornament is all 
that is required, a space of from three to twelve acres 
will contain a very nice collection of the finest species, 
but if cultivated for profit, of course there is no limit to 
the space that might be occupied with them. Many pro¬ 
prietors of moor land have planted thousands of acres 
with the fir, the spruce, and the larch, and thus rendered 
their barren land productive and profitable. With such 
large operations we do not profess in these papers to 
have anything to do with. All that we wish is to increase 
