2 BULLETIN 53, U. S. DEPAKTMENT OF AGEICULTURE. 



Area, in square yards, of object-lesson roads constructed, etc. — Continued. 



Material. 



1905 



1906 



1907 



1908 



1909 



1910 



1911 



1912 



19131 





















10,831 





44,944 



51,246 



76,376 



72,587 



96, 107 



60,333 



11,330 



578 



900 



9,774 



14,806 



56 253 





































4,819 





















2,804 

 2 607 





















Gravel 



8,804 



4,197 



11, 722 



4,608 



65,793 



71,376 



4,610 



177,960 



59,942 



13,057 



63,730 



Slag 





Sand clay 



19, 178 



19, 443 



85,571 



42,634 



205, 032 



218, 177 



103,876 



128, 496 

 5,337 







400 



5,877 







3,392 

 14,020 

 85,967 



2,041 



1,630 



319,456 









Shell 



933 

 12,132 



'27,' 042' 









40,646 

 160, 932 



Earth 



651, 109 



140,933 



556, 663 







Total 



79,203 



87,951 



200,711 



223,208 ! 690. 059 



1,007,569 



485, 102 



722, 855 



488, 331 







' 



1 Includes experimental roads. 



During the fiscal year 1912-13 the Office of Public Roads, under 

 the general direction of the chief engineer, Vernon M. Peirce, and the 

 immediate control of the highway engineer in charge, B. F. Heidel, 

 supervised the construction of object-lesson roads as follows: One 

 bituminous-concrete, 1 bituminous-macadam, 7 macadam, 4 gravel, 1 

 gravel-macadam, 1 brick-cinder, 14 sand-clay, 1 sand-gumbo, 3 shell, 

 and 9 earth. Three other roads begun during the past fiscal year 

 were not completed, and the description of the work on them will be 

 reserved for the next annual report. Exclusive of the assistance 

 afforded by the office in the form of the salaries and expenses of its 

 engineers, the object-lesson roads described below cost the various 

 communities in which they were located $94,323.68. 



This bulletin includes, in addition to the object-lesson work of 

 the office, a brief account of the experimental work for the past 

 fiscal year, and reports of the bridge work and inspection of object- 

 lesson roads as conducted under the immediate supervision of 

 Charles H. Moorefield, highway engineer, and E. W. James, chief 

 inspector, who report to the chief engineer. 



BITUMINOUS-CONCRETE ROAD. 



Chevy Chase Club, Md.^ — A driveway through the grounds of the Chevy Chase 

 Club, approximately 1,395 feet long, was graded and surfaced with bituminous 

 concrete on a broken-stone base between May 7, 1913, and June 28, 1913. 

 Three days were lost on account of unfavorable weather and 12f days for 

 other reasons. The road is 10 feet wide for a length of 150 feet, 15 feet wide 

 for 945 feet, and from 20 to 23 feet wide for 300 feet, making a total area of 

 2,807 Fquare yards. Of this area 2,602 square yards were surfaced with bitu- 

 minous concrete and 205 square yards with Portland cement concrete. The 

 maximum cut was 1.5 feet, the maximum fill 0.5 foot, and the maximum 

 grade remained 7 per cent. The adjacent land is rolling and the soil is mica- 

 clay. The drainage structures had all been constructed before this work was 

 begun and were paid for separately. 



