DUST PREVENTION AND ROAD PRESERVATION, 1916. or 
e 
Section No. 1—Refined water-gas-tar preparation.—Although it 
seemed, in February, 1916, that this experiment probably would not 
require a re-treatment in the summer, wear developed uniformly 
until the mat became so thin that it was thought best to re-treat. 
This was done by hand in October, and the quantities and costs 
appear in Table 58. The same type of bituminous material was used 
as in the original surface treatment and the covering was torpedo 
sand. Analysis of a sample of the bituminous material is shown in 
Table 56. At the time of last inspection, March 28, 1917, this exper- 
iment had a mat generally intact and uniformly worn. Near the 
north end there were a few small breaks in the surface near the center 
of the roadway. 
TasLe 56.—Analysis of water-gas tar preparation ' used in re-treatment of experiment 
No. 1, Washington, D. C. 
SaClie Se N alin aay PEM ORS OAS a eRee Seo oe De GREE See Nearer eee ees mea PAL 
Beetucmascostiyesrmeler, O0n ©. 50.C. Gan. ss cree oe eiere ao steno aes 18.5 
eTACeMipihee CAT DOM scat cra says Seioie cies eterna n/a mara) panera, Wotays aravetay alae pat el oceaar eee 2. 05 
Per cent Per cent 
a by DY 
Distillation: volume. weight, 
WGHET . o SGUG BECO RBC MUCG ROU OO OEE OSS DOOR RUB nc Te OFM BE aS Ee 0.0 0.0 
arstaliehtroils! (GomMlOl©s)) ie je. SNE ETE eS ee 1.0 Or 
Second altos; GlO° to L709 Cee eek 2a ee eis ey & x3 
eawaynoil sr (lh 70c tor2107 Cs)uss ee aie es sere ee eels uo LAO) 19.1 
Heamygouen(2707to 3007 Cisse oes Saas: 2 10.0 9.6 
IEYEHO)a1 TYEISH OTe Ae ee PR te me et cage ee eT 5 ae 67.5 70. 3 
Ny eal apa MI AL BIS See Meta rae Si ee A a A 100. 0 100. 0 
During the autumn and winter of 1916 this experiment was sub- 
jected to a much heavier steel traffic than ever before, owing to con- 
struction operations on the department grounds. About 100 feet 
from the south end of the section a wide trench was cut through the 
roadway and was filled with cmders. A second trench, about 15 
inches wide, had been cut through at a pomt 275 feet from the south 
end, and when filled the surface treatment had been patched. At the 
time of inspection the fill had settled somewhat and probably will have 
to be repaired. Other than the repairs over these trenches, the surface 
needed slight repairs and a light re-treatment during the summer. 
Section No. 2—Asphaltic petroleum, surface treatment.—As con- 
templated at the time of last inspection report, this experiment re- 
quired considerable patching and a re-treatment. during the summer 
of 1916. The quantities and costs appear in Table 58, and the char- 
acteristics of the bituminous material used are given in Table 57. 
This was the same as used in the original treatment. 
1 Fairly viscous fluids. 
2 The 270° to 300° C. portion showed 5 per cent insoluble in dimethy1! sulphate. 
