EOADS AND BEIDGES, JULY 1, 1913-DEC. 31, 1914. 3 



ing concrete, at $0,199 per square yard, $182.37 ; setting forms, $15.63 ; and mis- 

 cellaneous labor, $10.50. 



BITUMINOUS-MACADAM ROADS. 



Dade County, Lemon City, Fla. — Work was conducted on an experimental 

 object-lesson road beginning about one-fourtb mile nortb of Lemon City, on the 

 Biscayne Drive, during January and February, 1914. Tbe work consisted of 

 the construction of five sections of bituminous-macadam road ; tbe stone was a 

 local coralline rock, with various bituminous materials for tbe top coat. The 

 surfaced width was 18 feet and the length 334.4 feet, making a total area of 

 668.8 square yards. 



The total cost of the work was $420.77, or $0,629 per square yard. 



Detailed description will be found in Progress Report of Dust Prevention and 

 Road Preservation for 1914. 1 



Palm Beach County, West Palm Beach, Fla. — Work was conducted on an 

 experimental object-lesson road beginning at a point about 2 miles south of 

 West Palm Beach, on the Miami-Quebec Highway, during April, 1914. The 

 work consisted of the construction of seven sections of bituminous-macadam 

 road. The stone was a local coralline rock, with various bituminous materials 

 for the top coat. The surfaced width was 15 feet and the length 860 feet, 

 making a total area of 1,433 square yards. 



The total cost of the work was $808.17, or $0,564 per square yard. 



A detailed description will be found in Progress Report of Dust Prevention 

 and Road Preservation, 1914. 1 



Augusta County, Staunton, Va. — Work was begun on a road leading from 

 Staunton toward Middlebrook on September 16, 1913. This office furnished a 

 representative for the purpose of instructing the local authorities in applying 

 the bituminous surface. He superintended the laying of one kind of bitumin- 

 ous material and turned this one section over to the local authorities on Sep- 

 tember 29, 1913, with 2* days lost due to bad weather. 



When the office representative arrived this road had been graded 21 feet 

 wide in both cuts and fills for a length of 1,700 feet. The subgrade, 15 feet 

 wide, had been prepared, the shaping was practically done, and most of the 

 first course of rock had been placed. 



The adjacent land is rolling and the natural soil is clay and rock. The 

 crushed rock was a limestone with good binding qualities and a fair wearing 

 quality. It was loaded into wagons by gravity from the bins, hauled about 

 three-quarters of a mile, and dumped on the road in piles and spread with 

 rakes and shovels. 



On the prepared subgrade the No. 1 stone, ranging from 2 to 3£ inches in 

 size, had been spread to a depth of 5 inches and rolled until compacted to 3i 

 inches. On this course was spread 3 inches of loose No. 2 stone, ranging from 

 three-fourths inch to 2 inches in size, and rolled until compacted to 2 inches. 

 The bituminous binder was spread on this course at the rate of 11 gallons to 

 the square yard. This was covered with screenings varying from one-fourth 

 to three-fourths inch in size. The road was then rolled, and a seal coat of 

 about one-half gallon of bituminous binder applied. The binder was delivered 

 in a tank car and heated by steam from a pump station of the Chesapeake & 

 Ohio Railroad. At the time of the departure of the office representative 2,106 



1 Bulletin No. 257, U. S. Dept. of Agriculture. 



