N THE chapter on the "Preparation of the Ground" it was advised that, after the land had been plowed, the subsoil plow should be used, and the ground thoroughly harrowed, then cross-plowed and again harrowed. Finally it may be rolled with a two-horse roller so as to break up the lumps of earth and leave the surface reasonably even and smooth. It has also been advised that, in order to show the proposed lines of the driveways and walks, a center line of stakes should be set according to the adopted plan, and at the same time it was urged that the lines of these driveways and walks should be most carefully studied from all points until it was felt that they were the best possible. Assuming then that these preliminary points have all been attended to, the next step toward the construction of roads and walks is to have two lines of stakes set equally distant from the center line showing the width of the proposed walk or driveway. If for a driveway, these stakes should be set not less than eight feet from the center line of stakes, and thus sixteen feet apart from each other, as a driveway with a width of less than sixteen feet would be too narrow for two carriages to pass comfortably, and, besides, would give the grounds a pinched contracted appearance.
If the stakes are being set for a foot-path, they should be set four feet from the center stakes, and thus eight feet apart from each other. A foot-path eight feet wide has enough width and looks well in the grounds.
As formerly suggested, it is again urged that all the good surface soil should be removed from the proposed road-bed (whether of driveway, walk, or any other contemplated gravel surface) and spread over those parts of the grounds where the natural soil is poor and shallow, or, if not required for that purpose, in any low spots which may need leveling up.
When this is done, the center line, as well as the side lines of stakes, should be carefully reset about every fifteen feet along the proposed roadway. Then three lines of levels must be run along the road-bed, one in the middle and one on each side. The Walk with Rustic Benches. Background of Pines and First cuts and fills must now be figured out, and the grade established, the quantities of soil to be moved being carefully figured so that the cuts and fills will balance each other, always keeping in view the economy of having the dirt moved as short a distance as possible.
After this is all calculated, it is time to have the grade-stakes set, one at the base of each of the line-stakes.
When setting the border grade-stakes, it must be seen that the stakes, on opposite sides of the road to be graded, are set exactly level with each other, for unless the two borders of the roadway or foot-path are level, not only does the road never look well, but it is not comfortable to walk or drive over. As the grade-stakes will be set alongside the line-stakes, they also will be at intervals of fifteen feet on the roadway, it being inadvisable to have them further away from each other. These grade-stakes should have sawed, square ends not less than one inch square.
After the border grade-stakes have been put in place, still another line of grade-stakes should be set, at equal distances apart, along the line of the road-bed, to guide the workmen in the grading of the surface. These grade-stakes should be set so as to give the road-bed a crown of one in sixty; for example, if the roadway is sixteen feet wide, it should be about three and one-half inches higher in the middle than at the sides, so that the rains will run off the middle of the road toward the sides, leaving the center of the roadway dry. Great care must be taken in this part of the work, as a road or walk has not a good appearance when there is too great a rise in the middle, and that such a road or walk is inconvenient and almost unpleasant for walking or driving over, will be evident. In staking the rise, the width of the road must always be taken into consideration, otherwise great mistakes may be made, and a walk which is eight feet wide should have no more than the proportion just mentioned, which would be a rise of one and three-quarter inches from the sides to the middle.
Formal Gardening. Walks Conversing to Fountain. Background Heavily Wooded.
At each of the grade-stakes, stout witness-stakes should be set, close against each grade-stake, and projecting about two feet higher, so that in the event of the grade-stakes being covered over with dirt, they may always be located by the witness-stakes, and thus the work will not be delayed through a surveyor having to be found to locate the lines or the grades.
For a driveway, the border grade-stakes should be set eight inches above the proposed finished gravel surface, thereby giving room for five inches of crushed rock and one inch of fine finishing rock, and thus leaving the border of soil about two inches above the finished rolled surface of the roadway.
For a walk, the same course in grading should be pursued, only in this case the border should be graded six inches above the grade of the walk instead of eight inches as recommended for the driveway. This would give four inches for the depth of rock, that depth being sufficient for a foot-path.
When these stakes for the driveway have all been set, the roadway can now be leveled to the required grade, namely, eight inches below the top of the established border grade-stakes, and six inches below the top of the road-bed grade-stakes.
Of course, some portions of the natural grade will be found to be above and other portions below the proposed grade of the driveway, but, all this having been carefully planned out as suggested earlier in this chapter, the portions of the roadway which are too high will now be moved to fill up to grade where the ground is too low. This part of the work is very easily carried out when it has previously been carefully planned and has also been surveyed and staked, so that the workmen will know both how deep to cut and to what grade they are to fill in.
Various materials may be used for the bottoming of roads and walks, such as stone, brickbats, clinkers, or, in short, any hard substance which contains nothing that would injure the roots of the plants. It is important to keep this in view, as plants situated near the border of a road quite frequently send their roots under the road-bed, and, if material injurious to plants were used, the plants could not fail to suffer. Each neighborhood generally has some local quarry which contains rock quite good enough for forming roads or walks for a pleasure-garden and grounds. Crushed rock of a brown color has a much better color effect, as contrasted with the green of lawns or shrubbery, than rock which is of a gray or white shade.
Before commencing to haul the rock for bottoming the roadbed, it should be seen that the road-bed is well shaped, evenly crowned, and rolled hard, for unless the road-bed is properly shaped before the rock is spread, it is almost impossible to get a good road, because the foundation rock would necessarily be of uneven depth and could not be evenly rolled. Besides, leaving the road-bed uneven would be the cause of greater expense, as the road would, in that case, have to be evened up by rock, and, as the expense of hauling rock is very considerable on account of it generally having to be brought from some distance, it would be much more expensive to fill up a road-bed in this way than by grading it with dirt from the grounds.
Driveway showing California Laurel (to the left of Illustration) and Oaks; also Ivy-Covered Stump.
The road-bed then being in shape and rolled smooth and hard, the work of setting the bottom rock should be commenced. Any kind of rock will be found good enough for the foundation layer of the driveway, provided it is not over two inches or two inches and a half in diameter. A mixture of all sizes up to six or eight inches in diameter does not make a good roadway, for it cannot be rolled evenly, nor does it form a close finish, as it leaves large open spaces and hard unevennesses. This bottom layer should be evenly spread about five inches deep. After the rolling is all done, the surface should be gone over with a shovel, and any ruts or chuck-holes which may have been left by the wagon wheels should be filled in, the object being to leave the whole surface as even as possible. It should then be rolled with a heavy roller at least three times, or until perfectly smooth. There must then be a layer of finishing rock or gravel which will pass through a half-inch mesh, spread evenly over the entire surface about one inch deep and rolled into proper condition.
This finishing coat, as a rule, is not put on until all the heavy work on the roads (such as hauling material for buildings and planting the grounds) has been completed.
Walk Lined with Dracaenas.