Gunnersbury House, A. Copland, Esq. - This is a fragment of a park, which was laid out by the celebrated Kent, about the year 1740. The old features remaining are some fine cedars and two pieces of rather naked water. The present house was built by Mr. Copland, on the summit of a brow, commanding a park of 50 acres, with the rich cultivated scenery of Middlesex beyond, and in the extreme distance the Surrey hills. Among the fine features of this place may be enumerated a straight terrace on the lawn in front of the house, terminating in an alcove at one end, and, at the other, passing through a triumphal arch to a winding walk, carried along the brow of the hilly part of the grounds, so as to display the leading features of the park and the distant scenery, on the one hand; and, on the other, highly kept lawn, with choice shrubs, and all the usual furniture of flowers, basins, fountains, sculptures, rockwork, basketwork, seats, and trellises; added to these, there are a very handsome billiard-room containing also an organ, a flower-garden, and a large piece of water. The flower-garden is included within a circular walk, with a smaller circle in the centre, and two semicircular basins of water, with an arcade of trelliswork. All the forms are perfectly simple, but they are very effective, especially when clothed, as they now are, by the most select plants. One circumstance in the plan of these beds deserves notice: they are placed on turf, but surrounded by a margin, of the breadth of 4 in., of gravel, within which is an edging of box, kept low and flat, so as to form an inner margin corresponding in width with the outer one. The effect is highly artificial, and appropriate to this description of flower-garden. The arcade of trelliswork consists of arches of iron wire, alternately rising and reversed, so as to give the idea of a festooned wreath of flowers. The only defect we found in this circle of festooned work was the want of breadth, which might be easily supplied by means of a few cross wires, so as tO retain a more ample mantle of vegetation. Among the blue flowers in this flower-garden were Anagallis Monelli and A. latifolia, the common convolvulus, Tradescantia, the blue verbena, the blue lobelia, and the heliotrope. Various little circular beds of mesembryanthemums were eminently beautiful as the sun happened to shine full upon them while we walked round. The piece of water is almost the only formal part of the pleasure-ground. At whatever point you stand, you see the entire outline, which is what botanists would call orbiculate, or, in common language, shaped like a horsepond. It would be easy to vary it by one or two narrow islands along the sides, being careful not to destroy breadth of effect by placing any near the centre, or equidistantly along the margin. Among the commendable practices, of which we saw a number at this place, we may mention that of using the vaults under a summer-house as a place for growing mushrooms. We found an excellent crop on these beds, even at this dry hot season, and were informed by Mr. Mills (the head gardener) that he had them in abundance all the year. In the drying ground we observed copper wires, about three sixteenths of an inch in diameter, instead of lines. The poultry yard and rabbitry are very complete; but the latter facing the south, and having a thin slate roof immediately over the hutches, the rabbits are found not to thrive quite so well in the summer time, as they do in the winter.