A visit to Newport, Rhode-Island, this season, and a close examination of some of the grounds and gardens there, has convinced us that the popular estimation in which the climate of Newport is held, is based upon sound reasons, and is no popular prejudice. Though Newport is part of the sea-coast range of New-England, its climate is mild and agreeable, to a degree known nowhere else in any of the middle or eastern states. This has not been well explained, but it is probably owing to an elbow of the gulf stream which bends inwards at this point of our coast, and ameliorates the climate for some miles in its neighborhood.

As absolute proof of the mildness of the winters, we may state that in the garden of Mr. Alfred Smith, (the sylvan museum of the island,) we saw in the most flourishing condition, the Evergreen Cypresses of the south of Europe, the Gold Dust tree (Aucuba japonica,) the Arbutus Unedo, the Portugal Laurel, the English Laurel, and the Chili Pine. (Arauca-ria.) Not one of these plants will stand the winter well without any covering elsewhere, (so far as we know,) north of Baltimore. At Newport they appear to grow with the freshness and the depth of verdure, that marks them in England - 4he finest climate for evergreens; and to carry out the resemblance of Newport to the best parts of England, we may mention also, and Catawba grape scarcely seen nowhere out of Great Britain. In Mr. Smith's garden we observed the Deodar Cedar, the Atlas Cedar, the Cryptomeria joponica, all the English Hollies, remarkably luxuriant, and showing none of the signs of having been pinched by winter, which all those, (except the Deodar) often do in our northern pleasure grounds.

Many of the grounds surrounding the gentlemen's summer cottages, have been planted lately with quantities of Hollies, Austrian Pines, English Laurels, etc, and Mr. Smith, who is perfectly conversant with all the gardening experiments of the island, informs us that 250,-000 ornamental trees have, to his knowledge, been planted in private grounds in and about Newport, within the last six years. These have partly been procured from American nurseries, but great numbers of evergreens of small size, have been imported from England and France. In ten years more the naked shores of the island will, we hope, be as leafy and beautiful as those of the Isle of Wight - for while many trees that thrive well in the interior will not thrive upon the salt air of Newport - there are many, as we have here pointed out, which the mild and soft climate favors, that will not thrive so well in any other part of the country - for at the south - where the winter temperature is the same, the summers are too hot.