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The bottom of the ditch may vary in width from three to twelve inches, or even more, as may be found necessary in order to carry the largest amount of water which is expected to flow through it at any one time.
Sometimes the only ditches necessary to carry off the surface water are those made by the use of the road machines or road graders. The blade of the machine may be set at any desired angle, and when drawn along by horses, cuts into the surface and moves the earth from the sides toward the center, forming gutters alongside and distributing the earth uniformly over the traveled way. Such gutters are liable to become clogged by brush, weeds, and other debris, or destroyed by pa.s.sing wagons, and it is therefore better, when the s.p.a.ce permits, to have the side ditches above referred to, even if the road be built with a road machine.
In order to have a good road it is just as necessary that water should not be allowed to attack the substructure from below as that it should not be permitted to percolate through it from above. Especially is the former provision essential in cold climates, where, if water is allowed to remain in the substructure, the whole roadway is liable to become broken up and destroyed by frost and the wheels of vehicles. Therefore, where the road runs through low wet lands or over certain kinds of clayey soils, surface drainage is not all that is necessary. Common side drains catch surface water and surface water only. Isaac Potter says:
"Many miles of road are on low, flat lands and on springy soils, and thousands of miles of prairie roads are, for many weeks in the year, laid on a wet subsoil. In all such cases, and, indeed, in every case where the nature of the ground is not such as to insure quick drainage, the road may be vastly benefited by under drainage. An under drain clears the soil of surplus water, dries it, warms it, and makes impossible the formation of deep, heavy, frozen crusts, which are found in every undrained road when the severe winter weather follows the heavy fall rains. This crust causes nine-tenths of the difficulties of travel in the time of sudden or long-continued thaws.
"Roads constructed over wet undrained lands are always difficult to manage and expensive to maintain, and they are liable to be broken up in wet weather or after frosts. It will be much cheaper in the long run to go to the expense of making the drainage of the subjacent soil and substructure as perfect as possible. There is scarcely an earth road in the United States which cannot be so improved by surface or subdrainage as to yield benefits to the farmers a hundred times greater in value than the cost of the drains themselves.
"Under drains are not expensive. On the contrary, they are cheap and easily made, and if made in a substantial way and according to the rules of common sense a good under drain will last for ages. Use the best tools and materials you can get; employ them as well as you know how, and wait results with a clear conscience. Slim f.a.gots of wood bound together and laid lengthwise at the bottom of a carefully graded drain ditch will answer fairly well if stone or drain tile cannot be had, and will be of infinite benefit to a dirt road laid on springy soils."
Subdrains should be carefully graded with a level at the bottom to a depth of about four feet, and should have a continuous fall throughout their entire length of at least six inches for each one hundred feet in length. If tile drains cannot be had, large, flat stones may be carefully placed so as to form a clear, open pa.s.sage at the bottom for the flow of the water. The ditch should then be half filled with rough field stones, and on these a layer of smaller stones or gravel and a layer of sod, hay, gravel, cinders, or straw, or, if none of these can be had, of soil. If field stones or drain tile cannot be procured, satisfactory results may be attained by the use of logs and brush.
If there be springs in the soil which might destroy the stability of the road, they should, if possible, be tapped and the water carried under or along the side until it can be turned away into some side channel. Such drains may be made of bundles of brush, field stones, brick, or drain tiles. They should be so protected by straw, sod, or brush as to prevent the soil from washing in and clogging them.
Most of the roads in this country are of necessity constructed of earth, while in a few of the richer and more enterprising communities the most important thoroughfares are surfaced with gravel, sh.e.l.l, stones, or other materials. Unless some new system for the improvement of public roads is adopted, the inability of rural communities to raise funds for this purpose will necessarily cause the construction of hard roads to be very gradual for some time to come. Until this new system is adopted the most important problem will be that of making the most of the roads which exist, rather than building new ones of specially prepared materials. The natural materials and the funds already available must be used with skill and judgment in order to secure the best results. The location, grades, and drainage having been treated in the preceding pages, the next and most important consideration is that of constructing and improving the various kinds of roads.
Of earth roads, as commonly built, it suffices to say that their present conditions should not be tolerated in communities where there are any other materials with which to improve them. Earth is the poorest of all road materials, aside from sand, and earth roads require more attention than any other kind of roads, and as a rule get less. At best, they possess so many defects that they should have all the attention and care of which their condition is susceptible. With earth alone, however, a very pa.s.sable road can be made, provided the principles of location, drainage, and shape of surface, together with that of keeping the surface as smooth and firm as possible by rolling, be strictly adhered to. In fact a good earth road is second to none for summer travel and superior to many of the so-called macadam or stone roads.
"Water is the great road destroyer," and too much attention cannot be given to the surface and subdrainage of earth roads. The material of which their surfaces are composed is more susceptible to the action of water and more easily destroyed by it than any other highway material.
Drainage alone will often change a bad road into a good one, while on the other hand the best road may be destroyed by the absence of good drains.
The same can be said of rolling, which is a very important matter in attempting to build or maintain a satisfactory earth road. If loose earth is dumped into the middle of the road and consolidated by traffic, the action of the narrow-tired wheels cuts it or rolls it into uneven ruts and ridges, which hold water, and ultimately results, if in the winter season, in a sticky, muddy surface, or if it be in dry weather, in covering the surface with several inches of dust. If, however, the surface be prepared with a road machine and properly rolled with a heavy roller, it can usually be made sufficiently firm and smooth to sustain the traffic without rutting, and resist the penetrating action of the water. Every road is made smoother, harder, and better by rolling. Such rolling should be done in damp weather, or if that is not possible, the surface should be sprinkled if the character of the soil requires such aid for its proper consolidation.
In constructing new earth roads all stumps, brush, vegetable matter, rocks, and bowlders should be removed from the surface and the resulting holes filled in with suitable material, carefully and thoroughly tamped or rolled, before the road embankment is commenced. No perishable material should be used in forming the permanent embankments. Where possible the longitudinal grade should be kept down to one foot in thirty feet, and should under no circ.u.mstances exceed one in twenty, while that from center to sides should be maintained at one foot in twenty feet.
Wherever the subgrade soil is found unsuitable it should be removed and replaced with good material rolled to a bearing, _i.e._, so as to be smooth and compact. The roadbed, having been brought to the required grade and crown, should be rolled several times to compact the surface.
All inequalities discovered during the rolling should be leveled up and rerolled. On the prepared subgrade, the earth should be spread, harrowed if necessary, and then rolled to a bearing by pa.s.sing the unballasted road roller a number of times over every portion of the surface of the section.
In level countries and with narrow roads, enough material may be excavated to raise the roadway above the subgrade in forming the side ditches by means of road machines. If not, the required earth should be obtained by widening the side excavations, or from cuttings on the line of the new roadway, or from pits close by, elevating graders and modern dumping or spreading wagons being preferably used for this purpose. When the earth is brought up to the final height, it is again harrowed, then trimmed by means of road levelers or road machines and ultimately rolled to a solid and smooth surface with road rollers gradually increased in weight by the addition of ballast.
No filling should be brought up in layers exceeding nine inches in depth. During the rolling, sprinkling should be attended to wherever the character of the soil requires such aid. The cross section of the roadway must be maintained during the last rolling stage by the addition of earth as needed. On clay soils a layer of sand, gravel, or ashes spread on the roadway will prevent the sticking of the clay to the roller. As previously explained, the finishing touches to the road surface should be given by a heavy roller.
Before the earth road is opened to traffic, deep and wide side ditches should be constructed, with a fall throughout their entire length of at least one in one hundred and twenty. They should be cleaned and left with the drain tiling connections, if any, in good working order.
Clay soils, as a rule, absorb water quite freely and soften when saturated, but water does not readily pa.s.s through them; hence they are not easily subdrained. When used alone, clay is the least desirable of all road materials, but roads constructed over clay soils may be treated with sand or small gravel, from which a comparatively hard and compact ma.s.s is formed which is nearly impervious to water. Material of this character found in the natural state, commonly known as hardpan, makes, when properly applied, a very solid and durable surface. In soil composed of a mixture of sand, gravel, and clay, all that is necessary to make a good road of its kind is to "crown" the surface, keep the ruts and hollows filled, and the ditches open and free.
[Ill.u.s.tration: Sand Clay Road in Richland County, South Carolina
[_Sand soil with nine inches of clay and two inches cover of sand_]]
Roads are p.r.o.ne to wear in ruts, and when hollows and ruts begin to make their appearance on the surface of an earth road great care should be used in selecting new material, with which they should be immediately filled, because a hole which could have been filled at first with a shovel full of material would soon need a cart full. It should, if possible, be of a gravelly nature, entirely free from vegetable earth, muck, or mold. Sod or turf should not be placed on the surface, neither should the surface be renewed by throwing upon it the worn-out material from the gutters alongside. The last injunction, if rightly observed and the proper remedy applied, would doubtless put an end to the deplorable condition of thousands of miles of earth roads in the United States.
A road-maker should not go to the other extreme and fill up ruts and holes with stone or large gravel. In many cases it would be wiser to dump such material in the river. These stones do not wear uniformly with the rest of the material, but produce b.u.mps and ridges, and in nearly every case result in making two holes instead of one. Every hole or rut in a roadway, if not tamped full of some good material like that of which the road is constructed, will become filled with water, and finally with mud and water, and will be dug deeper and wider by each pa.s.sing vehicle.
The work of maintaining earth roads will be much increased by lack of care in properly finishing the work. The labor and money spent in rolling a newly-made road may save many times that amount of labor and money in making future repairs. After the material has been placed it should not be left for the traffic to consolidate, or for the rains to wash off into the ditches, but should be carefully formed and surfaced, and then, if possible, rolled. The rolling not only consolidates the material, but puts the roadbed in proper shape for travel immediately.
If there is anything more trying on man or beast than to travel over an unimproved road, it must be to travel over one which has just been "worked" by the antiquated methods now in vogue in many of the states.
The traveled way should never be repaired by the use of plows or scoops.
The plow breaks up the compact surface which age and traffic have made tolerable. Earth roads can be rapidly repaired by a judicious use of road machines and road rollers. The road machine places the material where it is most needed, and the roller compacts and keeps it there.
The labor-saving machinery now manufactured for road-building is just as effectual and necessary as the modern mower, self-binder, and thrasher.
Road graders and rollers are the modern inventions necessary to permanent and economical construction. Two men with two teams can build more road in one day with a grader and roller than fifty men can with picks and shovels, and do it more uniformly and more thoroughly.
Doubtless the best way to keep an earth road, or any road, for that matter, in repair is by the use of wide tires on all wagons carrying heavy burdens. Water and narrow tires aid each other in destroying streets, macadam, gravel, and earth roads. Narrow tires are also among the most destructive agents to the fields, pastures, and meadows of farms, while on the other hand wide tires are road-makers; they roll and harden the surface, and every loaded wagon becomes in effect a road roller. Nothing so much tends to the improving of a road as the continued rolling of its surface.
Tests recently made at the experiment stations in Utah and Missouri show that wide tires not only improve the surface of roads, but that under ordinary circ.u.mstances less power is required to pull a wagon on which wide tires are used. The introduction in recent years of a wide metallic tire which can be placed on any narrow-tired wheel at the cost of two dollars each, has removed one very serious objection to the proposed subst.i.tution of broad tires for the narrow ones now in use.
Repairs on earth roads should be attended to particularly in the spring of the year, but the great mistake of letting all the repairs go until that time should rot be made. The great want of the country road is daily care, and the sooner we do away with the system of "working out"
our road taxes, and pay such taxes in money, the sooner will it be possible to build improved roads and to hire experts to keep them constantly in good repair. Roads could then secure attention when such attention is most needed. If they are repaired only annually or semiannually they are seldom in good condition but when they are given daily or weekly care they are almost always in good condition, and, moreover, the second method costs far less than the first. A portion of all levy tax money raised for road purposes should be used in buying improved road machinery, and in constructing each year a few miles of improved stone or gravel roads.
The only exceptions to the instructions given on road drainage are found in the attempt to improve a sand road. The more one improves the drainage of a sand road the more deplorable becomes its condition.
Nothing will ruin one quicker than to dig a ditch on each side and drain all the water away. The best way to make such a road firm is to keep it constantly damp. Very bushy or shady trees alongside such roads prevent the evaporation of water.
The usual way of mending roads which run over loose sandy soils is to cover the surface with tough clay or mix the clay and sand together.
This is quite an expensive treatment if the clay has to be transported a great distance, but the expense may be reduced by improving only eight or ten feet or half of the roadway.
Any strong, fibrous substance, and especially one which holds moisture, such as the refuse of sugar cane or sorghum, and even common straw, flax, or swamp gra.s.s, will be useful. Spent tan is of some service, and wood fiber in any form is excellent. The best is the fibrous sawdust made in sawing shingles by those machines which cut lengthwise of the fiber into the side of the block. Sawdust is first spread on the road from eight to ten inches deep, and this is covered with sand to protect the road against fire lighted from pipes or cigars carelessly thrown or emptied on the roadbed. The sand also keeps the sawdust damp. The dust and sand soon become hard and packed, and the wheels of the heaviest wagons make but little impression upon the surface. The roadbed appears to be almost as solid as a plank road, but is much easier for the teams.
The road prepared in this manner will remain good for four or five years and will then require renewing in some parts. The ordinary lumber sawdust would not be so good, of course, but if mixed with planer shavings might serve fairly well.
Roads built of poles or logs laid across the roadway are called corduroy roads, because of their corrugated or ribbed appearance. Like earth roads, they should never be built where it is possible to secure any other good material; but, as is frequently the case in swampy, timbered regions, other material is unavailable, and as the road would be absolutely impa.s.sable without them at certain seasons of the year, it is well to know how to make them. Roads of this character should be fifteen or sixteen feet wide, so as to enable wagons to pa.s.s each other. Logs are superior to poles for this purpose and should be used if possible.
The following in regard to the construction of corduroy roads is from Gilmore's _Roads, Streets, and Pavements_:
"The logs are all cut the same length, which should be that of the required width of the road, and in laying them down such care in selection should be exercised as will give the smallest joints or openings between them. In order to reduce as much as possible the resistance to draft and the violence of the repeated shocks to which vehicles are subjected upon these roads, and also to render its surface practicable for draft animals, it is customary to level up between the logs with smaller pieces of the same length but split to a triangular cross section. These are inserted with edges downward in the open joints, so as to bring their surface even with the upper sides of the large logs, or as nearly so as practicable.
"Upon the bed thus prepared a layer of brushwood is put, with a few inches in thickness, with soil or turf on top to keep it in place. This completes the road. The logs are laid directly upon the natural surface of the soil, those of the same or nearly of the same diameter being kept together, and the top covering of soil is excavated from side ditches.
"Cross drains may usually be omitted in roads of this kind, as the openings between the logs, even when laid with utmost care, will furnish more than ample water way for drainage from the ditch on the upper to that on the lower side of the road. When the pa.s.sage of a creek of considerable volume is to be provided for, and in localities subject to freshets, cross drains or culverts are made wherever necessary by the omission of two or more logs, the openings being bridged with planks, split rails, or poles laid transversely to the axis of the road and resting on cross beams notched into the logs on either side."
The essential requirement of a good road is that it should be firm and unyielding at all times and in all kinds of weather, so that its surface may be smooth and impervious to water. Earth roads at best fulfil none of these requirements, unless they be covered with some artificial material. On a well-made gravel road one horse can draw twice as large a load as he can on a well-made earth road. On a hard smooth stone road one horse can pull as much as four horses will on a good earth road. If larger loads can be hauled and better time made on good hard roads than on good earth ones, the area and the number of people benefited are increased in direct proportion to the improvement of their surface.
Moreover, it is evident that a farm four or five miles from the market or shipping point located on or near a hard road is virtually nearer the market than one situated only two or three miles away, but located on a soft and yielding road. Hard roads are divided here into three cla.s.ses--gravel, sh.e.l.l, and stone.
Although it is impracticable, and in many cases impossible, for communities to build good stone roads, a surface of gravel may frequently be used to advantage, giving far better results than could be attained by the use of earth alone. Where beds of good gravel are available this is the simplest, cheapest, and most effective method of improving country roads.
[Ill.u.s.tration: GRAVEL ROAD NEAR SOLDIERS' HOME, DISTRICT OF COLUMBIA]
In connection with the building and maintenance of gravel roads the most important matter to consider is that of selecting the proper material. A small proportion of argillaceous sand, clayey, or earthy matter contained in some gravel enables it to pack readily and consolidate under traffic or the road roller. Seaside and river gravel, which is composed usually of rounded, waterworn pebbles, is unfit for surfacing roads. The small stones of which they are composed, having no angular projections or sharp edges, easily move or slide against each other, and will not bind together, and even when mixed with clay may turn freely, causing the whole surface to be loose, like materials in a shaken sieve.
Inferior qualities of gravel can sometimes be used for foundations; but where it becomes necessary to employ such material even for that purpose it is well to mix just enough sandy or clayey loam to bind it firmly together. For the wearing surface or the top layer the pebbles should, if possible, be comparatively clean, hard, angular, and tough, so that they will readily consolidate and will not be easily pulverized by the impact of traffic, into dust and mud. They should be coa.r.s.e, varying in size from half an inch to an inch and one-half.
Where blue gravel or hardpan and clean bank gravel are procurable, a good road may be made by mixing the two together. Pit gravel or gravel dug from the earth as a rule contains too much earthy matter. This may, however, be removed by sifting. For this purpose two sieves are necessary, through which the gravel should be thrown. The meshes of one sieve should be one and one-half or two inches in diameter, while the meshes of the other should be three-fourths of an inch. All pebbles which will not go through the one and one-half inch meshes should be rejected or broken so that they will go through. All material which sifts through the three-fourths inch meshes should be rejected for the road, but may be used in making side paths. The excellent road which can be built from materials prepared in this way is so far superior to the one made of the natural clayey material that the expense and trouble of sifting is many times repaid.
The best gravel for road-building stands perpendicular in the bank; that is, when the pit has been opened up the remainder stands compact and firm and cannot be dislodged except by use of the pick, and when it gives way falls in great chunks or solid ma.s.ses. Such material usually contains tough angular gravel with just enough cementing properties to enable it to readily pack and consolidate, and requires no further treatment than to place it properly on the prepared roadbed.
Some earth roads may be greatly improved by covering the surface with a layer of three or four inches of gravel, and sometimes even a thinner layer may prove of very great benefit if kept in proper repair. The subsoil of such roadway ought, however, to be well drained, or of a light and porous nature. Roads constructed over clay soils require a layer of at least six inches of gravel. The gravel must be deep enough to prevent the weight of traffic forcing the surface material into weak places in the clay beneath, and also to prevent the surface water from percolating through and softening the clay and causing the whole roadway to be torn up.
Owing to a lack of knowledge regarding construction, indifference, or carelessness in building or improving, roads made of gravel are often very much worse than they ought to be. Some of them are made by simply dumping the material into ruts, mud holes, or gutter-like depressions, or on unimproved foundation, and are left thus for traffic to consolidate, while others are made by covering the surface with inferior material without any attention being paid to the fundamental principles of drainage. As a result of such thoughtless and haphazard methods the road usually becomes rougher and more completely covered with holes than before.
In constructing a gravel road the roadbed should first be brought to the proper grade. Ordinarily an excavation is then made to the depth of eight to ten inches, varying in width with the requirements of traffic.
For a farm or farming community the width need not be greater than ten or twelve feet. A roadway which is too wide is not only useless, but the extra width is a positive damage. Any width beyond that needed for the traffic is not only a waste of money in constructing the road, but is the cause of a never-ending expense in maintaining it. The surface of the roadbed should preferably have a fall from the center to the sides the same as that to be given the finished road, and should, if possible, be thoroughly rolled and consolidated until perfectly smooth and firm.