FARMERS' INSTITUTES. 4f 



often be secured, and the gravel delivered at the crossing of the road to 

 be improved. Railroads have frequently done this work at in'iees but 

 little above actual cost. 



In selecting- gravel, don't use sand, and on the other hand, don't use 

 cobble stones. The pebbles should not be much less than 1-8 of an inch,, 

 nor greater than one inch in diameter. Gravel in most cases would be 

 better for screening to take out the sand as well as the large stones- 

 Very coarse gravel can be made into excellent road material by running 

 it through a crusher. 



Material of satisfactory kind now being found, we turn to the road 

 bed. This should be graded, giving due regard to all that has heretofore 

 been said as to location, grades, shape and drainage. In shaping the sub- 

 grades^ allowance should be made for the gravel that is to form the 

 finishing coat, so as to leave the finished surface at correct giade and of 

 proper form. Before the gravel is applied the sub-grade should be thor- 

 oughly rolled with a four ton roller. The gravel then should be applied 

 in layers not more than three or four inches deep. Thus if 12 inches of 

 gravel is to be applied it should be put on in three layers; if but 6 inches, 

 in two layers, and each layer compacted with a roller or allowed to remain 

 till hardened by traffic before the following layer is applied. Gravel- 

 roads cannot be. compacted by I'olling to such an extent as broken stone, 

 but a considerable rolling will put the gravel in much better shape for 

 immediate travel and thus very much hasten its thorough consolidation. 



If the road bed is from 20 to 24 feet wide the graveled area should 

 comprise 16 feet in the center when a double track is required and but 

 S feet when a single track only is desired, which track may be either in 

 the center or to one side of the center, leaving the other side .for an earth 

 track. (See plans 1 and 2.) 



■ MACADAM ROADS. 



While it is true that the vast milage of our roads will ever be dirt 

 roads and most of those that are improved must be gravel roads, yet there 

 are many localities where the principal roads can be macadamized at a 

 cost that will not be burdensome to the community. I refer to parts of 

 the State that are located in the vicinity of quarries containing suitable 

 rock for this purpose, and many other localities wdiich are so thickly 

 covered with field boulders or cobble stones that they have to be re- 

 moved from the land before it can be successfully tilled. Parts of Bay,. 

 Huron, Saginaw and Tuscola counties are so located that stone from' 

 Bay Port quarries can be used at reasonable cost, while most of the coun- 

 ties bordering on the St. Clair river should be supplied with stone from= 

 Monroe and Trenton (quarries at prices quite within their reach. Where 

 railroad freights do not exceed 50 cents per cubic yard stone from some 

 of these quarries would no doubt be the most economical material to use. 



There has been a marked tendency of late years by manufacturers to 

 produce portable rock crushers which can be purchased by one or more, 

 townships, or townships and villages where suitable boulders abound. 

 The stone can thus be crushed near where it is to be used. This would 

 no doubt reduce the cost of stone roads to a minimum, but, even with 

 conditions thus favorable, it must not be imagined that good stone roads. 

 can be built without much care and considerable expense. 

 6 



