52 BULLETIN 407^ U. S. DEPARTMENT OF AGRICULTURE. 



T^. ^.,, ,. Percent Percent 



Distillation: by vol. bywt. 



Water 0.0 0.0 



First light oils (to 110° C.) 0. 0. 



Second light oils (110° to 170° C.) 0.0 0.0 



Heavy oils (170° to 270° C.) 1 10. 9 8. 7 



Heavy oils (270° to 315° C.) ^IIA 10.4 



Pitch residue 3 77, 7 go. 9 



Total 100. 100. 



The covering was applied somewliat too heavily. This was in a 

 measure due to a desire to prevent excessive bleeding in the spring. 

 Reference to the preceding report will show that the original treat- 

 ment bled very freely, and already, at the date of inspection (Feb. 

 28) the re-treated surface became sticky on sunny days. Material 

 is now distributed along the road ready for use at the first indication 

 of stickiness. The surface is in excellent condition now, fully as 

 good as when originally built, and at the date of inspection there 

 was not a break in it. 



Experiment No. 7. — ^Asphaltic Petroleum, Cold Application. 



Reference to the last report will show that this experiment was 

 showing signs of weakness in the fall of 1914. It should have been 

 re-treated at that time, as conditions in the spring of 1915 have since 

 clearly shown. The mat was quite generally forced aside or carried 

 away along two broad, shallow ruts when the surface became muddy 

 in the late winter of 1914-15, and in many places the road metal 

 began to ravel. These ruts were from 18 inches to 2 feet wide and 

 frequently the entire hand could be slipped under a straight edge 

 laid across the rut. A very large amount of patching was necessary 

 to put the experiment into condition for a re-treatment. The re- 

 treatment was given June 21 to 23, 1915, using the same bituminous 

 material as in the original re- treatment (Table 51), and covering with 

 torpedo sand, represented by the analysis given in Table 52. The 

 quantities and costs are given in Tables 54 and 55. 



At the time of the inspection this experiment was in excellent 

 condition, except on one or two very short sections where the rutting 

 was excessive last spring. The re-treatment application was very 

 light and there appears to be no noticeable accumulation of mat. 

 The experiment will probably require re-treatment late in the summer 

 of 1916. 



1 Clear. 



2 Clear; showed 10.0 per cent insoluble in dimethyl sulphate. 



3 Hard, glossy. A 315°-350° C. fraction showed 12.5 per cent insoluble in dimethyl sulphate. 



