OBJTECT-LESSON" AND EXPERIMENTAL EOADS^ 1912-13. 7 



hauled 300 feet for the roller. Four tons of fuel was used at the crusher and 

 5J tons by the roller. 



The equipment consisted of a stone crusher having 73 cubic yards' capacity 

 per 9-hour day, an engine, a 10-ton roller, slat-bottom wagons, and hand 

 tools. Convict labor and teams owned by the county were used. The cost 

 to the county per day per convict and per mule was $0.45. The total cost of 

 the road was $647.15, making a rate of $0,232 per square yard. 



The principal items of cost were : Preparing the subgrade, $22.95 ; quarrying, 

 $117.45; hauling to the crusher, $66.60; crushing, $50.40; hauling from the 

 crusher to the road, $132.94; spreading the stone, $22.95; sprinkling, $8.11; 

 rolling, $68.95 ; stacking and loading screenings, $31.05 ; shaping shoulders, 

 $11.70 ; loss of time due to bad weather, $57.35 ; and incidental expenses, $76.70. 



North wiLKESBOEO, N. C. — Work was begun on a macadam road leading from 

 Northwilkesboro toward Wilkesboro on October 2, 1912, and was discontinued 

 on December 21, 1912. Thirteen and one-half days were lost on account of bad 

 weather. A section of road 800 feet in length was entirely completed and an 

 additional length of 494 feet was partially completed. The section completed 

 follows the Yadkin River, and the entire road is subject to overflow at flood 

 seasons. To remedy this condition the grade of the road was raised and the 

 macadam was laid on a Telford base. 



The natural soil is clay and sil and the adjacent land is level. There was no 

 cut, and the maximum fill was 3.9 feet and the average fill 2.1 feet. The 

 maximum grade of 5.85 per cent was reduced to 2.5 per cent. 



A total length of 1,294 feet was graded 30 feet wide. All the material for 

 the embankment was taken from pits located at an average distance of three- 

 eighths mile from the road and in no case more than one-half mile. It was 

 loosened with a plow, loaded with shovels on slat-bottom wagons, and spread 

 by hand. 



A subgrade 16 feet wide was prepared for a distance of 1,294 feet and a 

 Telford base 12 inches thick was laid upon it for the same distance. A macadam 

 surface was laid upon this base to the same width for a distance of 800 feet. 

 The surface was laid in two courses, each 3 inches thick compacted, and each 

 course was bonded with screenings. The stone used on the bottom course 

 consiste of pieces from 1^ to 3 inches in size, and the stone used in the second 

 course ranged from one-half inch to 1* inches. The screenings consisted of 

 material ranging from dust to particles one-half inch in size. 



The Telford base and the macadam surface were both made from mica 

 gneiss obtained from the same quarry. This material possesses excellent bind- 

 ing and wearing qualities. It was quarried at an average distance of 1^ miles 

 from the road, crushed at the quarry, loaded into dump wagons by means of a 

 chute j-'rom the bins, and hauled to the road, where it was spread with forks. 



The following drainage structures were constructed : One reinforced concrete 

 culvert 2 by 4 feet by 29 feet long; one reinforced concrete culvert 2 by 6 feet 

 by 30 feet long ; one reinforced concrete culvert 2 by 6 feet by 28.5 feet long ; and 

 one woodeu-box culvert 2 by 3 feet at an intersecting road. 



The equipment consisted of one stone crusher with a capacity of 25 cubic 

 yards per day, elevator, bins, one 10-tcn roller, six li cubic yard dump wagons, 

 slat-bottom wagons, one turn plow, and hand tools. 



The labor cost for men was $0.12^, $0,131, and $0.15 per hour, and double 

 teams cost $0.30 per hour. The working day was 10 hours long. 



The total cost of the road was $3,293.29, which is at the rate of $1.8875 per 

 square yard. The principal items of cost were as follows : Excavation and 

 embankment, 979 cubic yards, at $0.40 per cubic yard, $391.60; clearing and 

 grubbing, 2,300.4 square yards, at $0.0017 per square yard, $4; shaping the sub- 



