20 BULLETIN 105, U. S. DEPARTMENT OE AGRICULTURE. 
Experiment No. 2. — Refined water-gas tar — Cold application. 
Location: From station 61+20 to station 135+60. 
Length: 7,3S0 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 Xo. 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.. 1 0.2 0.2 
Second light oils 110°-170° C do 23.3 2.4 
Heavy oils 170°-270° C do 1 2S. 24. 3 
Heavy oils 270°-315° C do 1 13.5 12.4 
Pitch residue do 55. 60. 2 
Total do 100. 99. 5 
Experiment Xo. 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 Xo. 3. 
Specific gravity 25° 25° C 0. 935 
Plash point °C 22 
Burning point °C 30 
Viscosity. Engler, 25° O, 50 c. c. specific 07. 
Per cent of loss at 163° C., 5 hours (20 grams) 27. 01 
Ploat test of residue (50° C.) (time) * 2'21" 
Per cent of total "bitumen insoluble in S6° B. naphtha 14. 22 
Per cent of fixed carbon 7. 90 
Per cent soluble in CS 2 (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. s Fairly viscous, slightly sticky, fluid. * Soft, sticky, glossy. 
