658 PROCEEDINGS OF SECTION H. 



lasting results, and portions of the road which were heavily coated 

 showed a somewhat glazed surface formed of oil and dust. The experi- 

 ments show us that the dust has been satisfactorily laid, and the ex- 

 perience gained will probably enable future trials to be carried out 

 more economically. From the point of view of wear and tear of the 

 road surface, the oiling has on the whole been advantageous ; the 

 wear appears to be less ; the surface of the road dries more quickly 

 after rain ; the number of loose stones picked up has been reduced ; 

 the combination of earth and dust on the surface also appeared to 

 make it a somewhat quieter surface. Westrumite was found too 

 costly, and its effects passed off under a fortnight. In the moist 

 climate of England it was found that calcium chloride, costing |d. per 

 square yard per application, promised to give good results. 



In France calcium chloride has been used for over 30 years, and 

 gives good results where the streets are periodically watered. 



In Adelaide the City Council have made several experiments 

 with phenolic, which is a preparation of crude petroleum, and is soluble 

 in water to a considerable degree. The oil is not saponified, as is the 

 case with other soluble oil preparations, but when mixed in the pro- 

 portion of one of oil and four of water becomes denser, and is apparently 

 of thicker consistency. It is spread on the roads from a centrifugal 

 watervan with perfect ease, and covers splendidly with Igall. of mixture 

 to five square yards of surface, and costing Jd. per square yard. One 

 application lasts a month under ordinary circumstances and three weeks 

 under heavy traffic. Apart from its dust-laying qualities, it can be 

 applied at any season of the year, and the surface treated does not 

 produce mud in winter, and the life of the road is materially extended. 

 It has been found sufficient for light trafficked roads to give six applica- 

 tions per annum, monthl}^ during January, February, March, April, 

 November, and December ; and 10 three-weekly applications on heavy 

 trafficked roads. The behaviour of phenolic on the Adelaide roads 

 seems to bear out Mr. Brodie's conclusions from the results of his 

 experiments in Liverpool. Another good feature is that its use in 

 streets that are watered greatly reduces the tendency of the surface 

 to form ruts and become corduroyed or wavy. These experiments 

 have been in progress during the past three years, and it seems that the 

 so-called dust fiend can be practically abolished — not simply abated — 

 by its use. Two sections of road are now under treatment here. One 

 portion being 7,000 square yards at the east end of South Terrace, a 

 favorite route for motorists ; the other of 16,000 square yards in Grote 

 ■Street west. The former had the last coat a week ago, while Grote 

 ^Street has not been touched for six weeks, to enable any members of 

 :this Congress to witness the next application of the preparation. 



In concluding, it is right to point out that this immunity from 

 local — not air-borne — dust can now be assured, but not for nothing ; 

 and it seems warranted to remark that if the boon is not worth l|d to 

 2d. per square yard per annum for tar-paving, tar-dressing, or treat- 

 ment with an oil preparation, then dust will continue ; for it is quite 

 certain that it will never be possible to lay dust at a less cost. 



