Bisbee daily review., 1914-01-29
SAND CLAY ROADS ARE ADAPTABLE TO NEEDS OF ARIZONA
Washington Authorities Tell How Construction Can Be Carried on to Best Advan- tage

WASHINGTON. Jan. 2S.--There are at present about 35.O0O miles of sand lay roads in the United States
 mainly in the Southern states. ac.
 cording to the office or public roads.
 U. s. Department of Agriculture. The
 time to work the roads is in the
 spring when the soil is damp. If the
 working of the roads is deferred un-
 til late in summer when they are dry they are not only much more difficult
 to put in proper shape but the cost of repair is greater than if they were worked early in the spring.
 Previous to 1894 comparatively lit tie, if any, of these reads existed. Ti'- popularity of this tyre of road is due to the facts that 1t is cheap. compar-
 ativey firm and durable. easy to onsuuct and repair, and that the ma terials out of which it is built are plentiful in many sections of the country.
 The sand-ciay road is made by mix ing the sand and clay in such a way that the grains of sand touch each otser, the spaces between the grains being filled with clay winch acts as a binder.
 The approximate mixture of sand and clay may be determined by filling a vessel with sample of the sand to be used, and another vessel of the same size with water. The water is | poured carefully into the sand until it reaches the point of overflowing. ! The volume of water removed from the second vessel represents approx | imately the proportion of lay needed. 1 The proper proportion of sand and 1 clay can lest be determined, how ever. as the work progresses. as some clay will contain mere sand than eth CTS. In fact. clays are very frequent | ly found which already ontain about the right proportion of sand
 If the road to be treated is sandy. the surface is first leyeled of and crowned with road machine. the [ crown being about one-half inch to the foot from the center to the sides. The clay is then dumped on the sur. face and carefully spread. SO that 1t will be from G to inches in depth at the center, and gradually decreasing in depth toward the sides. A layer of clean sand is then usually added which is thoroughly mixed with the clay, either by trac or by means of blows and disk or tooth harrows.
 The best results have been obtained by thoroughly mixing or pudding the materials when wet. For this req son. it is desirable that the mixing dedone in wet weather. The mixing an be left so the traffic alter the materials have been properly placed. hut this involves whole winter and spring of bad road. and even then the mixing is not always satisfactory. In all cases, it is advisable to dress the read with a road machine or split log drag after the materials have been Thoroughly mixed. ana to give it a rown of not more than inch or less than three-fourth inch to the foot from the center to the sides. light coating of sand may then be added Tie use of the road machine or drag should be continued at frequent in. tervals until the surface is smooth and firm.
 If the road 10 be treated Is com. posed Of clay, it snould first be brought to a rough grade with road machine. The surface should then be plowed and thoroughly pulverizei . by narrowing to a depth of about inches after which 1t is given crown or slope, of about one-half inch to the . foot from the center to the sides. It is then covered with to s inches of clean, sharp sand. which is spread thicker in the center than at the sides. The materials should then be mhixed with blows and harrows while they arc comparatively dry. after which they are finally puddled with harrow during wet weather If lay works to the surface ana the road becomes sticky, more sand should be added
 The road is then shaped. rowned and ditehed in the usual manner with a read machine This should he NNh' ""'h 'hN huiidtc lS SOIL Vet stin enough to pack well under the roller or the traffic. Wide but shallow ditches should be provided on both sides of the road, and culverts of crossdrains should be placed wher. ever water flows across the road for it Is exceedingly important that the sand on clay roads be we'll drained. Atter'the clay on sand, or the sand on lay road is completed, 1t should be carefully maintained until the sur face becomes firm and smooth. The construction of this type Of road is by no means a quick operation. If soft sticky places appear, more sand should be added. and if loose, sandy places are found, more clay Is needed. It Is just as important to attend to these small details as to any other part of the work, for, if they are neglected, the road is liable to fail.
 Extraction of nitrogen from the at. mosphere on large scale for use as fertilizer Is proposed by Canadian capitalists who have obtaineI cjn. I