DUST PREVENTION AND EOAD PRESERVATION, 1914. 19 



original construction left the road flat and inadequately drained. 

 These are now showing the strain of more or less continued dampness 

 from underneath. The gravel section of this experiment has a 

 markedly better appearance than the trap section. 



The surface of experiment No. 2 in Bradley Lane is in fairly good 

 condition and free from bad holes or depressions. 



Experiment No. 3 (Asphaltic Petroleum — Cold Application). 



The surface of this experiment also began to fail rapidly during the 

 summer of 1914, and the failure seemed most pronounced at first on 

 the section where rather coarse gravel had been used for a covering 

 material. Moreover, during the winter of 1913-14, not only was the 

 surface cut through because of culvert repairs, but several rather large 

 areas heaved as a result of frost action. This latter damage was due 

 to the partial burning out of some of the surfacing bitumen by bonfires 

 set along the outer edge of the road. In a few places along the sides 

 of the road the surface mat had cracked to some extent. 



A new treatment was therefore applied between September 23 and 

 27, in which the same grade and character of oil as that originally 

 applied was used. The application was made by permitting the oil 

 to run from the bung of the barrel and sweeping it over the surface 

 with rattan push brooms. From station 135 + 00 to station 144 + 00, 

 where the original surface was still fairly smooth and intact, the appli- 

 cation was at the rate of 0.13 gallon per square yard, while over the 

 remainder of the experiment it was at the rate of 0.18 gallon per 

 square yard. The average was 0.176 gallon per square yard. The 

 application was immediately covered with clean torpedo sand. 



Table No. 12 shows the characteristics of the bituminous material 

 used, and the cost data will be found at the end of this supplementary 

 report. 



Table 12. — Analysis of asphaltic petroleum. 



Specific gravity 25°/25° C 0. 932 



Flash point °C. . 35 



Burning point °C. . 70 



Viscosity, Engler, 50 c. c. at 25° C, specific 61. 9 



Loss. 5 hours at 103° C, 20 grams per cent. . 22. 94 



Float test of residue at 32° C. (time) 5 / 53" 



Float test of residue at 50° C. (time) V 22" 



Percentage of total bitumen Insoluble in 86° i>. naphtha 13. 07 



Fixed carbon per cent.. 7. 62 



So] u hie in CS 2 (total bitumen) do 99. 90 



Organic matter in oluble do io 



anic matter in oluble do 00 



Total do j oo. oo 



