PLANK ROADS. The manifest ad vantage of these roads over every other, has led to their general adoption in some of the Western States, and their general extension through the western part of this State (N. Y.). Next to steam railroads, they are the most useful form of road for conveyance.
In the most generally approved system of construction, two parallel rows of small sticks of timber (called indifferently sleep ers, stringers or sills) are imbedded in the road, three or four feet apart. Plank, eight feet long and three inches thick, are laid upon those sticks across them, at right angles to their direction. A side track of earth, to turn out upon, is care fully graded. Deep ditches are dug on each side, to insure perfect drainage; and thus is formed a plank road.
Laying them out.—In laying out a plank road, it is indispensable, in order to se cure all the benefits which can be derived from it, to avoid or cut down all steep ascents.
A very short rise of even considerable steepness may, however, be allowed to remain, to save expense ; since a horse can, for a short time, put forth extra ex ertion to overcome such an increased re sistance • and the danger of slipping is avoided by descending upon the earthen track.
A double plank track will rarely be ne cessary.
No one without experience in the mat ter can credit the amount of travel which one such track can accommodate. Over a single track near Syracuse, 161,000 teams passed in two years, averaging over 220 teams per day, and during three days 720 passed daily. The earthen turn-out track must, however, be kept in good or der ; and this is as y, if it slope off prop erly to the ditch, for it is not cut with anv continuous lengthwise ruts, hut is only passed over by the wheels of the wagons which turn off from the track and return to it. They thus move in curves, which would very rarely exactly hit each other, and this travel, being over the earth, tends to keep it in shape rather than to disturb it.
Covering.—The planks having been properly laid, as has been directed, should be covered over an inch in thickness with very fine gravel or pebbles, from which all the stones or pebbles are to be raked, so as to leave nothing upon the surface of the road that could be forced into and injure the fibres of the planks. The grit of the sand soon penetrates into the grain of the wood and combines with the fibres and the dropping upon the road to form a hard and tough covering like felt, which greatly protects the wood from the wheels and horses' shoes. Sawdust and tan bark have also been used.
j The road is now ready for use. • Laying.—The planks should be laid directly across the road, at right anglesi or "square," to its line. The ends of the
planks are not laid evenly to a line, but project three or foni inches on each side alternately, so as to prevent a rut being formed by the side of the plank track,. and make it easier for loaded wagons to get upon it, as the. wheels, instead of scraping along the ends of the planks when coming towards the track obliquely after turning off, will, on coming square against the edge of one of those project ing planks, rise directly upon it. On the Canada roads every three planks project' three inches on each side of the road al ternately.
Durability .--A plank road may require a renewal either because it has worn out at top by the travel upon it, or because it has been destroyed at the bottom by rot. But, if the road have travel enough to make it profitable to its builders, it will wear out first, and if it does, it will have earned abundantly enough to replace it twice over, as we shall see presently. The lia bility to decay is therefore a secondary consideration on roads of importance.
Decay.--As to natural decay, no hem lock road has been in use long enough to determine how long the plank can be pre: served from rot. Seven years is perhaps a fair average. Different species of hem lock vary greatly ; and upland timber is always more durable than from low and wet localities. The pine roads in Canada generally last about eight years, varying from seven to twelve. The original To ronto road was used chiefly by teams hauling steamboat wood, and at the end of not six years began to break through in places,• and not being repaired, was principally gone at the end of ten years. Having been poorly built, badly drained, not sanded, and no care bestowed upon it, it indicates the minimum of durability: Oak plank cross-walks are in Detroit, the plank being laid fiat as on those of pine. It is believed that oak plank, well laid, would last at least twelve or fifteen years: One set of sleepers will outlast two plank ings. Several Canada roads have been relaid upon the old sleepers, thus much lessening the cost of renewal.
The following table shows the number of Plank Roads in the State of New York : Total 2761 miles. The tolls which the farmers pay are not taxes, in one sense of the term—they are saved in the larger loads they arc enabled to draw, the greater speed at which they are enabled to travel, the wear and tear of harness, gearing, and animal strength ; and the pleasure of riding on a smooth plank road in com parison with an old corderoy one is very great.