30 BULLETIN 105, U. S. DEPARTMENT OF AGRICULTURE. 



resulting in the formation of depressions and corresponding humps. 

 On July 1 1 the section was repaired and given a light surface treat- 

 ment with the material originally applied. The larger depressions 

 were filled with 1-inch limestone and the water-gas tar preparation 

 which had been used on section No. 1. The small depressions were 

 filled with fine screenings and the oil originally used on this section. 

 All humps were removed with a mattock. When such repairs had 

 been made, oil was applied at the rate of 0.10 gallon per square yard 

 throughout the most traveled area by allowing it to run from the 

 bung of the barrel and distributing it with hand push brooms. The 

 application was covered with a thin layer of torpedo sand. 



The total cost of maintenance for the year was $25.49, or 2.33 

 cents per square yard for the entire section. 



When inspected in January, the general appearance of the surface 

 was satisfactory, but the wearing carpet appeared to be developing 

 numerous fine cracks throughout the entire length. The portion 

 over the steam pipes required further repair in the early winter, and a 

 change in the form of construction at this point will probably be 

 made. 



Section No. 3. — Residual petroleum. 



As noted in Circular No. 99, this section showed a tendency to 

 become muddy in wet weather, and after periods of continued rain 

 the surface was covered with a deep oily mud, which traffic gradually 

 worked into low ridges along the edges of the road. By summer 

 the surface of the macadam began to be exposed throughout the 

 traveled way, and a light treatment with the oil originally used 

 was made on July 9, 1913. The oil was applied at the rate of about 

 0.10 gallon per square yard throughout the most traveled area in the 

 same manner as on section No. 2 and was covered with torpedo sand. 



The total cost of this work was $20.65, or 2.92 cents per square 

 yard, for the entire section. 



The section now presents a generally satisfactory appearance 

 excepting for a small area on the grade at the west end. The treat- 

 ment is largely worn off here, but this is almost entirely due to the 

 condition of the adjoining pavement and gutter, where water is held 

 for some time after a storm and continually carried on the oiled 

 section by traffic. 



Section No. 4. — Asphaltic petroleum. 



This surface gave excellent service in both wet and diy weather, 

 but, owing to the light treatment which had been given, it gradually 

 wore off until the underlying macadam was exposed in places through- 

 out the traveled way. A second application of about 0.10 gallon 

 per square yard of the oil originally used was made in July, 1913, 



