42 STATE BOARD OF AGKICULTURE. 



The work will consist in preparins: the sub-grade aud piovidiug suitable 

 drainage in the same manner as for gravel. The width of space to be 

 macadamized should be 8 or 16 feet according as a single or double track 

 is to be improved. Earth shoulders should be raised on each side of this 

 space, after which the sub-grade must be thoroughly rolled with a roller 

 weighing not less than 4 tons and preferably 5 or 6 tons. This rolling 

 must continue till no more compacting is possible. If the road bed is 

 composed of clay or loamy soil 5 or 6 inches of sand or gravel placed on 

 the sub-grade before the stones are spread will add very much to the 

 durability of the road. When the sub-grade is thoroughly rolled a layer 

 of crushed stone not greater than 2| inches in any dimension may be 

 spread upon the prepared grade. If the finished macadam is to be six 

 inches thick, this first layer of loose stone must be spread four inches 

 thick, as it will consolidate by rolling to about three inches. As soon as 

 the first layer is evenly spread the roller should be passed a number of 

 times over the loose stones to thoroughly compact them. Then a binder 

 course of stone screenings or bank gravel J to one inch thick should be 

 (n-enly spread over the stone and wet down with a horse sprinkler till 

 the screenings are thoroughly saturated and partly washed into the voids 

 of the stone. This can .be more cheaply done in country practice by 

 allowing a good rain to do the sprinkling, provided the work can be done 

 when the weather is suitable. Ordinarily no harm -^ill be done by post- 

 poning the rolling till the weather is favorable. The rolling should con- 

 tinue till no more compacting is possible. The road will ordinarily have 

 to be passed over twelve or fifteen times with a five ton horse roller. 



After the first course has thus been prepared the second or top layer 

 can be put on in the same manner, using this time, rather more of the 

 binding material. Enough should be used to somewhat more than fill 

 the voids in the stone. Thi.s last course will need about one-third more 

 rolling than the first. The immediate success of the road will largely 

 depend on the thoroughness of the watering and rolling. 



DISCUSSION. 



Mr. Graham: Would you plow in the center of the highway to turnpike it? 



F. F. Rogers: No. After the roadbed is once made hard, don't disturb it. Do 

 not abuse the grader either by pulling sods and soft dirt up into the center of an 

 otherwise hard road. 



Geo. T. Powell: Would you not urge the use of wide tires? 



tP. F. Rogers: Most assuredly. I would go so far as to urge the passing of 

 laws compelling the use of tires certainly four inches wide on all vehicles carry- 

 ing loads. 



Mr. : There would be little need of a roller if all farmers used wide tires. 



It is the narrow tires that destroy the roads. 



Q. W-ouId yon recommend the use of wide flat stone at the bottom of gravel 

 roads ? 



F. F. Rogers: Usually uot, but if the ground was very soft, I might do so. 



Q. By what method can we induce a town board to go into systematic road con- 

 sti notion? 



F. F. Rogers: I do not know. 



Mr. : Wo raise enough money to make good roads, but we spoil them 



l)oth by our method of building and our method of use. 



Q. What width of tire do you ins.'st on? 



F. F. Rogers: From three and one-quarter inches up. 



Q. Is crude petroleum good for road building? 



F. F. Rogers: I have henrd of good success with il, but it is too expensive for 

 general intrnduetioo. 



