The Colfax Gazette

HIGHWAY BUILDING.

IMPROVING EARTH ROADS WITH CLAY AND SAND.

How to Mix and Apply Them to Secure the Best Results-The Use of Road Machines In Building These Highways.

In an interesting address delivered at the Greenville (Mich.) good roads convention Frank F. Rogers, C. E., had the following to say regarding the improvement of earth roads:

If you must always have an earth road and cannot get gravel or stone at a reasonable cost, put clay on the sand and sand on the clay. When these become suitably mixed, they will form a sort of hardpan, making a very good road surface at most seasons of the year. Of course, the clay is good when hard and dry and the sand quite passable when the weather is so wet that nobody wants to travel, but to secure a medium earth road, good the greatest number of days in the year, that it is possible to make it, this is the best method that we can prescribe.

It should be borne in mind that neither improvement is very good until suitably mixed, and clay should be applied to sand in a manner to secure that mixture as speedily as possible and vice versa.

Decide on the width of a given road between ditches—say twenty to twenty-four feet, not much narrower and not much wider. These are economical widths, and the lack of uniformity in this particular is one of the greatest evils of our lack of system in road building all over this country. Bring the road to a suitable crown from twelve to eighteen inches above the side gutters. This, however. will have to be varied to meet the special needs of drainage for the locality, and should a large ditch be required on a narrow road it should be entirely outside the regular gutter, which will protect the vehicles from the danger of tipping over.

To prepare the bed it may have to be plowed toward the center, but, if so, do not disturb the old roadbed unless absolutely necessary. After plowing, harrow thoroughly, take a road machine and shape the whole bed to a perfectly rounded shape and roll til no more compacting is possible with a roller weighing four tons or more. A farm roller is of little use for this purpose.

After the bed is properly shaped and rolled as described take a road machine and crowd enough earth to each side of a central strip of such width as it may be desirable to cover with clay or gravel. This being done, clay should be applied on sand to the depth of five or six inches where no gravel is used and to the depth of three or four inches where a dressing of as much gravel can be placed upon the clay. After the clay is applied, it may be leveled with a road machine if well pulverized, or, if lumpy, it may be leveled by, first rolling to crush the lumps, then harrowing till smooth, but in each case it must be rolled till hard after a smooth surface has been secured.

Where no gravel is used the clay must be covered with from one to two inches of sand by reversing the road machine and crowding a little of the surplus sand from the sides to the center. This will prevent the roads from becoming muddy at the first wet spell. If a top dressing of gravel is used, it should be applied to the thin coat of clay immediately after rolling, then be brought to a true surface by the use of a road machine and rolled till it is thoroughly compacted. If the weather is dry, the gravel should be kept sprinkled during the final rolling.

When sand is used on clay, we usually secure as good results as by putting clay in sand, for it does not always prevent mud when the ground is extremely soft. A clay road should always be well piked with good side ditches, which must quickly take the water to its nearest natural outlet, which in turn must always be so well kept as to take the water at once away from the road allowance. Sand should be applied to clay after the picking is done, without forming any depression for its reception. as has been recommended for gravel. Sand should never be applied at a season of the year when a long dry spell is expected, but rather immediately before wet fall weather and winter sets in, so that by the next season it may become sufficiently mixed with clay to produce the condition already referred to. The same practice should be employed when any considerable depth of loose gravel is applied to a clay soil with the expectation that travel will make it hard.

The application of sand and gravel to clay, as above described, can be done in layers, giving time for the first layer to pack before the second is applied It is often advisable to wait till the next fall before the second layer is applied, thus giving time to watch results and use just the depth required to secure the best effect. as well as to economize material. After all this Is done, we have not secured a permanent road suited to heavy traffic, and we shall be obliged to look to the better grades of gravel and broken stone to produce any roads that may really be called permanent.

The Care of Earth Roads.

Earth roads should be repaired, particularly in the spring and fall of the year, but the mistake of letting them take care of themselves during the balance of the year should not be made. The greatest need of the common road in this country is daily or weekly care. A road receiving daily attention will require no extensive repairs and instead of becoming worse will gradually improve. It is minute and frequent homeopathic treatment that the earth road needs.