34 BULLETIN 105, U. S. DEPABTMENT OF AGEICULTUEE. 



product originally used and was then covered with a layer of clean 

 limestone screenings which would pass a 1-inch screen. The surface 

 was first swept by hand push brooms, and the oil was applied by 

 allowing it to run from the bungs of the barrels and distributing it 

 with brooms. The surface was not rolled. A torrential rain inter- 

 rupted the work when the south half of the section had been com- 

 pleted. Some of the oil was washed into the gutters and this is no 

 doubt responsible for the fact that the southern end of the section 

 now presents a rougher appearance than the north half. 



Table 33 shows the characteristics of the bituminous material used. 



Table 33. — Analysis of as phallic petroleum' 1 used in second surface treatment of section 



No. 9. 



Specific gravity 25725° C 0. 959 



Flash point ° C 38 



Burning point ° C : 80 



Viscosity, Engler, 25° C, 50 c. c. specific 153.3 



Per cent of loss at 163° C, 5 hours (20 grams) 25. 05 



Float test of residue (50° C.) 2 1'29" 



Per cent of total bitumen insoluble in 86° B. naphtha 7. 84 



Per cent of fixed carbon 4. 86 



Per cent soluble in CS» (total bitumen) 99.92 



Per cent of organic matter insoluble 08 



Per cent of inorganic matter insoluble 00 



Total.... , 100.00 



The materials and cost data for the second surface treatment of 

 sections Nos. 8 and 9 are given in Table 34 ; as follows: 



Table 34. — Materials arid cost data for second treatment of sections Nos. 8 and 9. 



Section S. 



Section 9. 



Area treated (square yards) 



Materials per square yard: 



Bitumen (gallons) 



Screenings (cubic yards) 



Cost data (cents per square yard) 



Sweep tag and cleaning 



Bitumen 



Application of bitumen 



Screenings 



Spreading screenings 



Rolling 



Total cost 



.25 



.012 



2.25 



( 3 ) 



2.54 

 .37 

 .30 



5.46 



.204 

 .012 



.210 

 1.426 



. 364 



2.684 



.526 



5.210 



Section No. 10. — Residual petroleum — Surface treatment. 



As had been anticipated, this section began to bleed excessively 

 with the advent of warm weather and required the application of 

 approximately 4 cubic yards of limestone screenings to prevent the 

 surface from picking up. The surface also began to wave badly, 



i Thin, fluid, with strong naphtha odor. 



- Soft, sticky, with slight flow. 



3 Automobile distributor used; cost charged in price of bitumen. 



