20 BULLETIN 105, XJ. S. DEPARTMENT OF AGBICULTTJBE. 



Experiment No. 2. — Refined water-gas tar — Cold application. 



Location: From station 61+20 to station 135+00. 

 Length: 7,380 feet. 



Bradley Lane was also treated for a width of 10 feet and a length, 

 of 835 feet east from the end of the preceding experiment. 



Date of application: September 23 and 24. 

 Temperature of tar: From 80° to 100° F. 



Table 22. — Analysis of refined water-gas tar used in experiment No. 2. 



Specific gravity 25°/25° C 1. 121 



Viscosity, Engler, 50° C, 50 c. c. specific 17. 5 



Per cent of free carbon 3. 33 



Distillation: By volume. By weight. 



Water Trace. Trace. 



First light oils to 110° C per cent. . i 0. 2 0. 2 



Second light oils 110°-170°C ., do 2 3.3 2.4 



Heavy oils 170°-270° C do i 28. 24. 3 



Heavy oils 270°-315° C do. . . . > 13. 5 12. 4 



Pitch residue do 55. 60. 2 



Total do ... . 100. 99. 5 



Experiment No. 3.— Asphaltic petroleum — Cold application. 



Location: From station. 135+00 to station 209+00. 

 Length: 7,400 feet. 



Date of application: From September 25 to September 30. 

 Temperature of oil: About 80° F. 



Table 23. — Analysis of asphaltic petroleum 3 used in experiment No. 3. 



Specific gravity 25°/25° C 0. 935 



Flash point °C 22 



Burning point °C 30 



Viscosity, Engler, 25° C., 50 e. c. specific 67.0 



Per cent of loss at 163° O, 5 hours (20 grams) 27. 01 



Float test of residue (50° C.) (time) * 2'21" 



Per cent of total bitumen insoluble in 86° B. naphtha 14. 22 



Per cent of fixed carbon 7. 90 



Per cent soluble in CS2 (total bitumen) 99. 89 



Per cent of organic matter insoluble 11 



Per cent of inorganic matter insoluble 00 



Total .- 100.00 



Details. — The oil was distributed in one application from station 

 135+00 to station 175 + 00, but on the remainder of this section about 

 0.25 gallon was applied on one day and another 0.25 gallon was 

 applied the next day, after which the screenings or gravel were 

 thrown on and the surface was rolled. From station 196 + 00 to sta- 

 tion 206 + 00 the macadam was first well sprinkled with water and 

 the oil was applied while the road surface was still moist. 



1 Clear. 2 Turbid. 3 Fairly viscous, slightly sticky, fluid. * Soft, sticky, glossy. 



