44. In the disposition of a great number of sorts of trees and shrubs in a plantation, some principle of order must be adopted. If the sorts are mixed together indiscriminately, the result is left to chance; if they are mixed together as equally as possible, then the result must necessarily be monotony, by the same number of kinds appearing in every part of the plantation; and, if each kind is kept in a group or mass by itself, there will be a risk of want of connexion, and, consequently, of unity in the general result In what way are all these difficulties to be overcome? Chiefly, we should say, by keeping each sort by itself and placing all those sorts nearest each other which are most alike; avoiding all formality in the outlines of the spaces allotted to each sort; and allowing these spaces to indent or ramify into one another. For this purpose, a knowledge of the natural system of botany is of the greatest use to the landscape-gardener; since it teaches him that all those trees and shrubs that belong to the same natural family, order, or tribe, admit of being brought together in the same group. The chief difficulty, therefore, will be in joining and connecting the groups together; and here a general rule may be given.

This is, that, when the groups have a near general resemblance to each other, such as those of the oaks with the elms, or Crataegus with Pyrus, then the union may be comparatively abrupt; that is, with a slight intermixture of the trees of both groups at the points where they join. But when the groups are very dissimilar, such as when the pine and fir tribe adjoin deciduous trees, the union must be very gradual, by means of numerous indentations and ramifications of the one group into the other. For example, suppose it were desirable to join a large mass of different species of oak (fig. 16. a) with a large mass of different species of pine (b); then, adjoining some of the evergreen oaks in the one group (a), place one or two pines, which grow in large and compact forms; and against some of the half-evergreen oaks, such as the Fulham or old Lucombe oak, place one or two pines of comparatively slender growth. In like manner, in the opposite group, evergreen and half-evergreen oaks may be planted among the pines, as at c, so as to form the extreme points of the oak group in that direction; and, as the one group approaches the other, not only evergreens and half-evergreens, but deciduous species, in equal numbers, may be introduced.

In all this, care must be taken to avoid a regular progression, and everything like formality. By such means a degree of union is at first indicated, and afterwards gradually increased, till, at a point equidistant between both groups, the number of plants belonging to each group will be equal. In this way, trees of the most opposite kinds may be introduced in the same plantation, even adjoining each other; but, where the plantation is of any extent, and many kinds are to be introduced, the introduction of opposite kinds adjoining each other can never be required. It can never, for example, in such a plantation, be requisite to unite the weeping willow with the Scotch pine; nor the poplars with the larch or the weeping birch; nor very large-growing trees, such as the elms, with trees of small size, such as the pyrus or the crataegus; nor trees with pinnated leaves, such as the ash and the Robinia, with such as have narrow, grass-like, or needle-like leaves, such as the deciduous cypress, end pines, and firs.

We repeat, that, for assembling trees and shrubs in a harmonious manner with reference to general appearance, excellent hints are afforded by the natural system of botany; and that the artist who has a general knowledge of this system, and understands, at the same time, the principles of composition as applied to lines and forms, which we have been endeavouring to lay down, can never be at a loss how to proceed.

45. Variety in the view obtained from the house, and from the different walks conducted through the grounds, is one of the grand desiderata in every place laid out in the modern style, whether its extent may be large or small With respect to the views from the house, the first thing to be attended to is, the disposition of the rooms, so that their windows may look in different directions. Unless this has been studied by the architect, it will be impotable, even in the finest situation, to produce much variety in the views. Suppose a house placed on a slope, commanding an extensive prospect: if all the rooms looked towards that prospect, all of them would have good views, but these views would not be varied; whereas if, from one side of the house, the windows of one room (say the drawing-room) looked out on a level flower-garden; and if, on another side, those of the dining-room looked up the slope; while, on a third side, those of the library, or breakfast-room, com- manded the distant prospect; there would be three distinct characters of view.

Now, in very small places (say of a quarter of an acre, or even less, in extent), this varied disposition of the rooms, or, rather, of the manner of lighting them, ought never to be lost sight of; because, altogether independently of distance, or of any object beyond the boundary fence, the views maybe rendered of different characters by the different kinds of trees and shrubs planted; by their different disposition; by a difference of form in the ground, and by a difference in the architectural ornaments, or by the absence of architectural ornaments altogether. Even a difference in the form and size of the window, or the absence or presence of a balcony or veranda, will altogether alter the character of the scenery. Wherever, therefore, a house stands isolated, and has a clear space of a few yards on each side of it, it may always have at least four different characters of view, independently of the effect produced by balconies, verandas, or other changes in the windows or foreground. Hence, also, in limited plots of ground, whatever is their shape, greater variety of view will be produced by placing the house nearer one end, or nearer one side, than in the centre. In the latter case, it is impossible to get depth of view from any side, and thus a great source of beauty is lost.