OSBORNE, the property of her most Gracious Majesty, is entitled, equally from public interest and its own importance, to the first notice under this head.—The situation is everyway eligible for the marine residence of a sovereign of the British Isles: for it commands a most extensive and animated prospect, including Spithead and other naval stations: has a beautiful sea-beach (with a private landing-place); and is sheltered by extensive woods and plantations. The original seat was a plain family mansion surrounded by park-like grounds, which have been extended by the purchase of several farms—including Barton (whose fine old Elizabethan manor-house has received a complete and judicious reparation): so that the estate is now most conveniently bounded on the west by the high-road from East Cowes to Newport; on the south by a branch of the same road to Ryde; on the east by a sheltered cove called King's Quay (as tradition will have it from the circumstance of King John there concealing himself for a time when opposed by the barons): and on the north-east by the beautiful Solent Channel. Thus compassed by the sea and the best roads in the island, it extends from north to south about two miles and a half, by nearly two miles from east to west; enjoying the most delightful variety of scenery, from the simple picture of rural life to the grandeur of our naval glory, and the majesty of the ocean itself.

The quality of the soil differs very considerably; but the worst is well adapted for oak-plantations; and the thorough draining and other improvements now carrying on will make the whole admirably suited for agricultural pursuits, to which H.R.H. the Prince Consort is very partial. A great part of the estate is enclosed by a park-fence; and through the luxuriant woods and undulating grounds, several miles of excellent private carriage-roads have been constructed, much more being in progress.

The Palace occupies the site of the old house; it is in the Palladian style (which so admirably admits the application to domestic architecture of the most beautiful features of the Grecian orders). Within the ballustrade of its lofty flat roof is a charming promenade in fine weather.

The flag-tower is 107 feet in height, the clock-tower 90, the first terrace-wall 17, and the second 10. The Royal Apartments are contained in the loftiest part of the building—they are handsome and spacious, and standing altogether in advance, command on every side the most uninterrupted views: at the back is the flag-tower, communicating with an open corridor which extends the whole of the north-west face of the building; and on the other side of the tower is the carriage-entrance, opening on pleasure-grounds adorned with the choicest varieties of ornamental shrubs—thriving with a luxuriance which promises well for the appearance of the estate, when the whole shall have been finished. The builder is T. Cubitt, esq.; but the design, we believe, was principally furnished by His Royal Highness Prince Albert himself—whose taste, and knowledge of the fine arts, well qualify him for the undertaking.

As it would be almost impossible to convey by verbal description a correct idea of the general appearance of this noble structure, we beg to refer our readers to the annexed Engraving—and also to the Views of Osborne, recently published in the "Vectis Scenery," and which may be purchased separately at 1s. each.

NORRIS is a noble specimen of the castellated mansion, having been built in imitation of an ancient Norman fabric—massive in its construction, and remarkable for a stern simplicity of style disdaining all minute decoration. From this circumstance, and some of the loftiest towers being enveloped in the most luxuriant ivy, the whole building has so venerable an air of antiquity, even when closely examined, that we can hardly suppose it to be the production of modern days: and enjoying too as it does an uncommonly fine position on the most northern hill of the island, its general aspect is truly magnificent in every point of view. It is scarcely necessary to add, that the castle commands a most interesting marine prospect.

Some of the rooms are of elegant dimensions, and the arrangement of the whole considered good—such indeed might be expected from the reputation of the architect, the late Mr. Wyatt. The stables, &c., are also on a very ample scale, and in the same plain, substantial style as the castle, for which they have not unfrequently been taken by strangers at the first glance.

The grounds are now well timbered: the plantations beautifully dressing the steep slope even to the water's edge. The utmost privacy might be enjoyed, for there is the accommodation of a good landing-place, and a carriage-road thence to the house.

Norris was the property of the late Lord Henry Seymour, who was engaged many years in its construction, and must in the course of a long period have expended immense sums in improvements that may be said to be now buried from our view. After his demise, it was two seasons chosen for the residence of their R.H. the Duchess of Kent and the Princess Victoria (during which time the latter improved remarkably in her health): and has since been purchased on very moderate terms by R. Bell, esq.—who greatly extended the scope of the grounds by fresh purchases of land, especially by some belonging to the Osborne estate—previously to her Majesty's negociating for its possession.

EAST COWES CASTLE, which enjoys a truly enviable site (for it combines an uncommon degree of shelter with the most extensive and animated prospect), is built in the bold style usually termed the Moorish, and has three handsome fronts of varied elevations, with a tasteful diversity of towers, mantled more or less by the most luxuriant ivy, and a great variety of elegant flowering plants. The Conservatory is a splendid addition; and the grounds, though not extensive, are very beautiful.