868 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



County is rei)lacinK its planlt culverts witli concrete. Since the road was built 

 about no miles have been constructed under engineering siipervlsion. A board 

 of business men has talcen great interest in the work. 



WiNCHESTKR, Tknn. — A macadam road was built at this place In December, 

 1909, and inspected in October, 1911. It was found to be in very good condi- 

 tion, excepting on the summits of hills, whore the fine material had blown 

 away, leaving the traveled part of the road bare. An attempt has been made 

 to maintain these places by supplying stone dust. The culverts and bridges 

 were found in good condition. An increase of automobile travel has resulted 

 from the construction of this road. No further road work has been attempted, 

 and this is thought to be traceable to the high cost of building. 



UNFINISHED WORK. 



Work bepnn on object-lesson roads at Fort Myers, Fla., in May, 

 1912, and at Jonesville, Va., in April, 1912, was still in progress at 

 the end of the fi.scal year. These roads will be described in the 

 annual report for 1913. 



HIGHWAY BRIDGES AND CULVERTS. 



During the past fiscal year much time has been devoted to collect- 

 ing and preparing useful data relating to the design and construc- 

 tion of highway bridges and culverts. A bulletin containing a num- 

 ber of tables and many typical designs has been prepared and will 

 soon be ready for publication. 



Only three separate bridge and culvert projects were undertaken 

 during the year. Many culverts were constructed in connection with 

 object-lesson roads, however, and a number of designs were furnished 

 for the guidance of local engineers. Replying to inquiries and fur- 

 nishing advice by letter also constituted a large part of the work. 

 A description of the object-lesson projects follows: 



GoLDSBORO. N. C. — Two abutments of Portland cement concrete for an 80-foot 

 span steel bridge over Little River were constructed on the Central Highway 

 in Wayne County at the State hospital. Work began on March 5, 1912, but 

 was discontinued on March 15 on account of continued high water. On April 

 23 the work was resumed, and the project was completed on June 10, 1912. The 

 foundations are gravel on the east side of the river and sand on the west side. 

 The excavation was made by hand, and the material was removed with wheel- 

 barrows and carts. Water was kept out of the cofferdams by means of a 

 li-inch diaphragm pump. The aggregate for concrete consisted of gravel 

 from i inch to 1? inches in diameter and fairly good sand. The materials were 

 mixed in the proportion of 1 part Portland cement, 2 parts sand, and 3i parts 

 gravel. Gravel was obtained from a pit and hauled 1^ miles. 



The haul for sand was one-half mile. The following quantities were han- 

 dled: Two hundred and fifty cubic yards of earth excavation, 168.5 cubic yards 

 of concrete, 147 cubic yards of gravel, 73 cubic yards of sand, and 261S barrels 

 of cement. 



The total cost of the abutments was $964.53. The principal items of cost 

 were excavation, 250 cubic yards, at $0,208 a yard. $51.96: hauling gravel, 147 

 cubic yards, at $0.39 a yard, $57.50; hauling sand, 73 cubic yards, at $0.14 a 

 yard, $10.20; cofferdam piling, $22.84; pumping, $53.76; screening gravel, 147 

 cubic yards, at $0.49 a yard, $73; forms, $47.54: mixing and placing concrete, 

 $149.58; cement, 261f barrels, at $1.44 a barrel, $376.92; lumber, $113.68; nails, 

 $4.55; and wire, $3. The laborers employed were patients from the hospital, 

 and the cost per patient was figured at $0.40 per 10-hour day. The cost of 

 foremen was $1 per day and of carpenters $1.50 per day. 



Dillon, S. C. — A 10-foot span concrete culvert, with reinforced slab super- 

 structure, was built at Dillon, S. C. Work began on September 7, 1911, but 

 several days were consumed in building a temporary road, and concrete con- 



