The difference between the greenhouse and conservatory is, that in the former, the plants are all kept in pots and arranged on stages, both to meet the eye agreeably, and for more convenient growth; while in the conservatory, the plants are grown in a bed or border of soil precisely as in the open air.
When either of these plant habitations is to be attached to the house, the preference is greatly in favor of the conservatory. The plants being allowed more room, have richer and more luxuriant foliage, and grow and flower in a manner altogether superior to those in pots. The allusion to nature is also more complete in the case of plants growing in the ground; and from the objects all being on the same level, and easily accessible, they are with more facility kept in that perfect nicety and order which an elegant plant-house should always exhibit.
On the other hand, the greenhouse will contain by far the largest number of plants, and the same may be more easily changed or renewed at any time; so that for a particular taste, as that of a botanical amateur, who wishes to grow a great number of species in a small space, the greenhouse will be found preferable. Whenever either the conservatory or greenhouse is of moderate size, and intended solely for private recreation, we would in every case, when such a thing is not impossible, have it attached to the house; communicating by a glass door with the drawing-room, or one of the living rooms. Nothing can be more gratifying than a vista in winter through a glass door clown the walk of a conservatory, bordered and overhung with the fine forms of tropical vegetation, golden oranges glowing through the dark green foliage, and gay corollas lighting up the branches of Camellias and other floral favorites. Let us add the exulting song of a few Canaries, and the enchantment is complete. Mow much more refined and elevated is the taste which prefers such accessories to a dwelling, rather than costly furniture, or an extravagant display of plate!
The best and most economical form for a conservatory is a parallelogram — the deviation from a square being greater or less according to circumstances. When it is joined to the dwelling by one of its sides (in the case of the parallelogram form), the roof need only slope in one way, that is from the house. When one of the ends of the conservatory joins the dwelling, the roof should slope both ways from the center. The advantage of the junction in the former case, is, that less outer surface of the conservatory being exposed to the cold, viz. only a side and two ends, less fuel will be required; the advantage in the latter case is, that the main walk leading down the conservatory will be exactly in the line of the vista from the drawing-room of the dwelling.
It is, we hope, almost unnecessary to state, that the roof of a conservatory, or indeed any other house where plants are to be well-grown, must be glazed. Opaque roofs prevent the admission of perpendicular light, without which the stems of vegetation are drawn up weak and feeble, and are attracted in an unsightly manner towards the glass in front. When the conservatory joins the house by one of its ends, and extends out from the building to a considerable length, the effect will be much more elegant; and the plants will thrive more perfectly, when it is glazed on all of the three sides, so as to admit light in every direction.*
The best aspect for a conservatory is directly south; southeast and southwest are scarcely inferior. Even east and west exposures will do very well, where there is plenty of glass to admit light; for though our winters are cold, yet there is a great abundance of sun, and bright clear atmosphere, both far more beneficial to plants than the moist, foggy vapor of an English winter, which, though mild, is comparatively sunless. When the conservatory adjoins and looks into the flower-garden, the effect will be appropriate and pleasing.
Some few hints respecting the construction of a conservatory may not be unacceptable to some of our readers. In the first place, the roof should have a sufficient slope to carry off the rain rapidly, to prevent leakage; from 40 to 45 degrees is found to be the best inclination in our climate. The roof should by no means be glazed with large panes, because small ones have much greater strength, which is requisite to withstand the heavy weight of snow that often falls during the winter, as well as to resist breakage by hail storms in summer. Four or eight inches by six, is the best size for roof-glass, † and with this size the lap of the panes need not be greater than one-eighth of an inch, while it would require to be one-fourth of an inch, were the panes of the usual size. On the front and sides, the sashes may be handsome, and filled in with the best glass; even plate glass has been used in many cases to our knowledge here.‡
* It need not be forgotten that very great improvements in greenhouse construction have been made since this chapter was written. The attached conservatory is now much more practicable and efficient than at that time. — F. A. W.
† Sixteen by twenty-four inches is now considered the standard size. — F. A. W.
‡ In the original edition the Author here proceeds to give practical suggestions regarding the heating of greenhouses and conservatories; but these directions are now so completely out of date that it seems better to omit them altogether. Instead of rewriting this portion of the book the Editor of the Seventh Edition prefers to recommend to the reader's attention the advice of the professional greenhouse builders who may be relied on in matters of this sort, and without whose help no one should undertake to build a private plant. — F. A. W.
Whatever be the style of the architecture of the house, that of the conservatory should in every case conform to it, and evince a degree of enrichment according with that of the main building.