By Geo. X. Woodward, Civil Engineer And Architect, No. 89 Broadway, New York.

The most prominent feature in the embellishment of a country estate, next to the mansion, is the approach, and, if of sufficient length, affords an opportunity for a display of engineering and artistic skill that no other specialty in rural improvement can equal. The approach-road is almost the first needed and most useful improvement, and from this fact is generally the soonest built, the least studied, and the least developed. All are willing to spend much time in select ing the true site for the house, and to call the best and most experienced talent to consult with, and yet hastily adopt a manner of approach that in some measure destroys the effect of that which is already good. It is quite as essential that the location of the approach-road be considered as that the house be well situated, or the general arrangement of the grounds convenient. The approach-road, as a general thing, admits of much variety in treatment, as it is not only a roadway for practical purposes, but one from which the grounds and the house are to be displayed to the best possible advantage, appropriating that which is good, and avoiding that not worthy of notice.

In tracing its course through all the variety which such roads usually embrace' we shall find there is much more skill and taste requisite to make the most of every thing than is generally supposed.

There are very many good sound reasons why the curve line should be adopted in the location of an ornamental road, and the facility given to use all natural resources for its embellishment is a strong one in favor of its use in the approach; but an indiscriminate and injudicious use of the curved line would not be wise. It is possible to distort and misapply almost any thing of beauty, as objects beautiful in themselves may form a hideous combination.

It is hardly necessary to repeat again the old threadbare piece of advice, that no curve should be used without a reason, and if none exist, one must be created; this is pretty well understood by every one, and needs no further remark. With regard to the straight line, there are places where its use is the most preferable, but its general use is not consistent with natural landscape treatment. In approaching the house by the straight avenue, as was customary in the formal style, the view was that of an architectural elevation, showing one front of the house. In the natural style, the house should be approached so that it is viewed perspectively; then, if there is variety in its form, the lights and shadows, and the well-managed accessories, give an artistical effect, and it becomes a picture.

It is not the best management to show all the good things one has at once, but rather to hold out inducements to lead one on in the pursuit of new pleasures, to find a new view, or a pleasing surprise.

The graduation of an approach should be well studied, so that the least quantity of earth is removed and deep cuttings and embankments avoided. It is a skillful matter to find that medium line that lies between all extremes, and still more difficult to please the fancies of all one's friends; yet such a line can generally be found, that in its gradual ascent, economical construction, easy flowing curves, and captivating views, shall explain to one of tasteful appreciation the reason why it occupies the position that it does.

It must be considered that well-adjusted gradients mark a high class of road construction, not necessarily more expensive, but most frequently quite the reverse. Scientific road-construction is as much a matter of economy in the first cost as it is in the annual repair, and there is quite as much effect developed in ascent and descent as there is in direction; and as a needless curve appears badly, so does a needless grade. The surface should be hard and smooth, and the road constructed of the best materials that can be had, and there should be in all that appertains to it a very decided difference from the public highway.

The width of a road must be governed to some extent by its length, and by the manner in which it is proposed to be kept. A wide road in fine order expresses an air of dignity and grandeur, yet, if too short, disappoints, because of the attempt to show what does not exist. As a general rule, the minimum width should be ten feet on approaches of moderate length, and increase in proportion to distance to 12,14,16,18, or 20 feet wide. The chances of passing carriages on a road increase with its length, yet on one of 300 to 500 feet long it is rare, except on unusual occasions, for carriages to meet. A wide road implies frequent use, and therefore neglect would destroy its impressions; neatness and fine keeping are essential to its importance and effect.

As a general rule, there should be no deviation from the approach road before reaching the house; to a stranger there should be no doubt raised as to which should be the proper road for him to take; and whenever it becomes necessary to branch off for any purpose whatever, it ought to be at points from which the house is in sight, and the branch roads take such a direction at first as to lead one to suppose that the house could not be reached by them; they should also be inferior in width and character, and, as far as possible, so managed as not to be mistaken for the main road. It may be a question difficult to decide, whether it is proper to see the coach-house, or other outbuildings, from the approach; although we would prefer to see no inferior buildings prior to seeing the house; yet, if they must be so treated, they ought to come in sight together, and the coach-house, or other building, be beautiful in its architectural appearance; and let its architecture be truthful, that it be not mistaken for any thing but what it really is; then it becomes an object of admiration, and soon left for the grander proportions of the mansion, without a thought that it would be more proper if occupying a less prominent position.

Considerable liberty may be taken with the location of an approach road, until that part of it is reached from which the house is visible; its general direction should then be towards the house, and not to pass it and return. A leading principle governing the location of an approach road is, that it is a road leading from the highway to the house, and that its course should be nearly direct, its entire alignment, graduation, construction, embellishment, etc, to be made with a view of developing a high order of beauty, usefulness, and effect, all of which is attainable at even less expense than in those locations which have little or no meaning, and which undervalue the true character of the landscape.