Strathfieldsaye, His Grace the Duke of Wellington. - We entered this noble park by an avenue a mile in length of elms, of a broader-leaved kind than the common English elm, and forming a tree of less altitude. The surface over which this avenue passes is undulating, which detracts somewhat from its first impression; but, as it is found to increase in length as we advance along, the sentiment of grandeur is recalled, and by prolongation is even heightened. We expected the surface of the grounds to, be flat, but were agreeably surprised to find a gentle hollow running through them in the direction of the length of the park, in the bottom of which hollow is the river Loddon, widened, and otherwise heightened in effect. The park is as well wooded as could be desired, with trees of all ages and sizes, but chiefly with old oaks and elms. The avenue of elms terminates at a short distance from the house, where the pleasure-ground commences on the left, and a plantation continues to the kitchen-garden and stable offices to the right. The approach road is still continued in a straight line between them, till it terminates in a circular road round a piece of turf about 100 ft. in diameter, to the left of which is the entrance front of the house; to the right, and also in front of the long avenue, are straight roads forming approaches in different directions. We met Mr. Cooper, the very polite and well-informed gardener, at the commencement of the pleasure-grounds, and walked round them and the kitchen-garden with him, leaving the place afterwards by the London approach, which branches from the avenue in a winding direction at about two thirds of its length from the house. The pleasure-ground is of very limited extent, and perfectly flat; but it contains some very fine specimens of cedars, larches, Weymouth pines, spruce firs, and other foreign trees, including, we may say, most of those which were to be found in the London nurseries about the middle of the last century. There was, in particular, the largest hemlock spruce, we believe, in England; we guessed it at between 40 ft. and 50 ft. in height; the trunk at the base at about 12 ft. in circumference, and the extent of the branches at between 15 and 16 yards. The trunk divides in two about the height of 2 ft. from the ground, otherwise there can be no doubt the tree would have grown higher. It stands on the centre of a semi-oblate spheroid (a flattened dome), and under the branches are a great number of seedlings. Whoever has grounds of his own, and wishes to have a memorial of Strath-fieldsaye, ought to beg from Mr. Cooper one of these plants. There is an old sickly catalpa in flower, from the appearance of which, and from that of those in the wood at White Knights, it is evident that a wet-bottomed soil does not suit this tree. Of Nyssa aquatica, there is a very fine specimen about 20 ft. high, and with a stem 6 in. in diameter. There are a very large liquidambar, several fine tulip trees, and decidedly the largest scarlet oak we ever saw: it was about 4 ft. in diameter, and above 100 ft. high. The trunk is straight, and covered with a clear smooth bark. Mr. Cooper informed us that he found, from some branches which he had had occasion to cut off this and other scarlet oaks, that the wood was remarkably hard and close-grained. Our readers are aware that the wood, when matured, approaches to the same colour as the leaves in autumn, viz. a deep scarlet, and that the same observation will apply to the wood of trees in general. There are good specimens of Laurus Sassafras and L. Benzoin. Among the common oaks are some, 5.5 yards in circumference at the surface of the ground, still growing vigorously. Standing at the lawn front of the house, the ground descends so gently to the Loddon as almost to appear a level surface; a little to the right is an artificial cascade, and to the left the river appears to be lost in meadow land, which on the opposite bank gradually rises, and is crowned with wood. The house itself is low, and altogether unworthy of the place, and there is scarcely a flower-bed on the lawn. There is an old orangery, and there are some orange trees in tubs, the sides of the latter neatly clothed with pine cones, and the surface of the mould covered with pebbles about the size of pigeons' eggs. The pine cones, besides giving a rustic appearance, exclude the heat; and the pebbles regulate the distribution of the water from the watering-pot.