But leaving this and the exquisite scenery of the lawn, we passed on by a winding carriage-road to a short distance to the conservatory. This was 350 feet long, 150 feet wide, and nearly 70 feet high; and when fully completed, is to have an additional length of 150 feet. The roof is an arch, and is covered with plate glass of the best kind, and so thick as to resist the heaviest hail. It is heated by iron tubes of hot water, and to these are added others for cold water, and the whole, if stretched out to a single length, we were informed would extend nearly six miles. The plants and trees here are distributed in open borders, each class being placed in the soil most proper for it, and the temperature so regulated as to suit their natural state as nearly as possible. Not far from the centre is an immense rockery rising about 50 feet high, and from the fissures of the thick slabs of stone that compose it, the cactus and other plants grow out as in their natural state. Half way up this huge precipice is a little lake with islets, and in this, water-lilies and other aquatic plants of the rarest and most beautiful kinds. A wild goat path leads to the top of the rockery, and beneath it is a wide, deep cave. The variety of shrubs and plants in this immense conservatory is very great; some of the trees already reach nearly to the top of the roof, and others presented dimensions gigantic in the extreme for those within a green-house. There are wide folding-doors at each end of the conservatory, and any time he pleases, the Duke can have a drive with his coach and four horses through it. Taking it altogether, it is by far the most magnificent thing of the kind we have ever seen. The whole cost of it is not less than half a million of dollars, which is but a little over the present annual income of its wealthy possessor.