Washington has gained more in outward appearance during the last half dozen years than it had before in half a century. It now has forty miles of better pavement than can be found in any other American town, and which compares favorably with any in Europe. This has made thorough street-sweeping practicable at small cost, and it results that, though the city is but poorly supplied with water, it is little afflicted with dust and is beginning to have a refreshingly clean aspect. But your readers will be more interested to know that on lines bordering these streets there now stand, fairly started, upwards of a hundred thousand well formed nursery-grown trees. Maples of several species are the more common, but there are representations (by the hundred) of at least six different genera. They are at present but club-headed saplings, hardly recovered from the shock of transplantation, or fairly settled in their new homes, and show none of the characteristic mature beauty of their several families. They have as yet, therefore, little value except as promissory notes, their growth to be discounted.

Nevertheless, seen as they constantly are, in long perspectives of uniform mass and color, their effect on the city is absolutely transforming and, if all goes well with them, Washington will in a few years be a new and glorified city; a capital that Americans may be proud of; supreme at least in its street beauty, whatever monstrosities in building fate may have in store for it. It can hardly fail in April and May to become a great pleasure resort.

But, more than this is to be said; the streets of Washington ("if all goes-well") will become a national tree-school, providing a standard, a stimulus and an incentive for the improvement of every village and hamlet in the land, and it may be well to add that if those able, as your readers must generally be, to foresee the future value of this work, will but let their intelligent applause be heard by members of Congress, it may prevent the occurrence of such a catastrophe, as under our present political customs, is always hanging over every beneficent enterprise as soon as it is well started. The commission of thoroughly competent experts, (Smith, Saunders and Saul,) should be warmly and effectively sustained at every pertinent opportunity.

They have yet a vast barrier of indifference, ignorance and active prejudice to overcome - not against their objects or the results of their work, but against the essential conditions of lasting success. Any one who has watched the various processes by which nine-tenths of all the street trees planted throughout the country are killed, stunted, distorted, mangled, and hardly one in a thousand suffered to attain its full, natural, manly beauty, will understand what they mean.

But in spite of what has been gained in the two particulars named, in a rapid development of gardening decoration, and in a large addition of private dwellings of a more or less elegant character, the greater part of Washington, outside the lines of its public plantations, yet retains much of its old, ante-bellum character, as of a slovenly woman here and there bedecked with trinkets both choice and rubbishy. Two offences to good taste are at this time particularly conspicuous, and all the more so because of the neat, trig and genuine quality of most of the new brick, tile and stone work.

The first results from efforts at cheap, tawdry and garish display in the embellishment of door-yards and lawns; the second from the necessity which has resulted in the recent grading down of streets, of leaving miles of formal earthworks between them and the houses fronting on them.

The fields about Washington are turfless, and good turf is only to be had by a tedious process, with great care and labor, and through the heat of summer only by a profuse command of water. There will soon be thousands of houses here, planted on banks from four to ten feet above the sidewalk, with flat, formal, steep slopes, such as even in the climate of England, and with the best of soil and gardening skill it is hardly possible to maintain turf upon suitable to carry the ■eye up to a house of refined materials and workmanship. The soil upon these slopes in Washing, ton is such as one sees in going there from Baltimore in the railway cuttings; a cracking, brick clay and gravel, bearing naturally almost nothing but stunted "broom-sedge." But were it much better, proper turf in such a situation in the climate of Washington would be out of the question, and nothing more incongruous with the cut stone and plate glass which often appears behind it, or more positively dreary and forlorn than what now generally stands upon them for turf, can be imagined. It compares with true turf as a ragged and dirty door mat compares with a table napkin.

As the arrangement has been forced upon the people, and such banks cannot, in many cases, be now avoided except at great expense, and as miles of them must be brought prominently into view to all visiting a city in which every American has a responsibility, the question of any generally-available, tidy treatment of them is one upon which good advice is greatly needed.

Nearly always it would be better, as far as practicable, to break art of rigidly mathematical forms; to obtain everywhere curving faces and especially to destroy angular crests. Next, a much more liberal use of shrubbery is desirable; not alone for decorative purposes, but for beautifully screening, or throwing into background retirement banks of dead and ragged grass. Even screens in the form of low, closely-trimmed hedges might be used. As Washington should appear well in winter they should be of evergreens; the best, if one had patience, probably of tree box or American holly; but it may be observed that after an exceptionally severe winter and a fearfully trying summer both yews and retinosporas of all species and varieties are looking very well in Washington.

After all that can be done in this way, however, should not the chief resort be to creepers?

In Europe such banks are sometimes seen covered very perfectly and yet very snugly and daintily with ivy. They may be seen also dressed with periwinkle, but it is rarely in good order. Evergreen honeysuckle would almost surely succeed, but might look too riotous. Has the evergreen Euonymus had a fair trial as a carpet, carefully spread and pegged? Could anything be done with creeping junipers? Perhaps in some cases it would do to make a facing of rough stone, to be generally overrun with honeysuckle and clematis, but with breaks and niches supporting sedums and other dry-rock plants, and with outbursts of yuccas and drought-enduring shrubs, as the smaller sumachs and mahonias. Suitable stone is to be easily obtained about Washington.

Still another expedient that might be admissible in some situations would be a trellis set at the base of the bank and of sufficient height to obscure it without obstructing the view toward the house. The trellis to be covered, of course, with vines. Wire netting stretched on iron frames, with the simplest possible supports of iron, would be best. But one of cedar or sassafras Poles might better be used than leave the banks in their present repulsive prominence. Such material is easily obtained any where about Washington, and it can be easily morticed and wire-bound together, and perfectly clothed with evergreen drapery in a single year. This would not be beyond the resources of a third class department clerk, a policeman or letter carrier, especially if he had boys to help him after school.

It would be of service to the Republic if you, good Mr. Editor, or if any of your experienced contributors would criticise these suggestions and name plants adapted to cover in a tidy way steept high slopes, facing the sun, in the climate of Washington, and advise how, without much gardening skill, labor or cash outlay, they may be so managed as not to appear at any time of year unsuitably faded, meagre, ragged or sickly.