NA TURE 



[September 14, 1905 



been devised, such as Akonia and Dustroyd. The 

 latter is a liquid manufactured from tar, and as it is 

 not soluble in water it should have the advantage 

 of greater permanence, being less affected by rain 

 than are soluble preparations. It is said to give an 

 asphaltic surface to the roads. 



A more permanent style of treatment is by means 

 of oil. So far this method has not received much 

 attention in this country, but in America it is being 

 tried on an extensive scale. This is the case at Los 

 Angeles, Cal. The secretary of the Chamber of 

 Commerce of that city gives the following details in 

 a report on the subject : — 



" For the past four or five years the use of oil on our 

 roadways has been increasing rapidly, and is now con- 

 sidered the best method for laying the dust, as well as of 

 making a serviceable roadway. It has been taken up by 

 the different boards of supervisors in the surrounding 

 counties as well as by the superintendent of streets in 

 Los Angeles, and we have now in the neighbourhood 

 300 or 400 miles of oiled roads within a radius of 60 

 miles of the city. It has been found, when properly 

 applied and the necessary attention given to it, that it 

 forms a smooth durable surface ; and in one case of a 

 road with a 6 per cent, grade treated with oil, it was 



a hard surface. For roads of this nature, that is, with a 

 hard surface, it has been found preferable in many cases 

 to use a light gravity oil, wliich is absorbed readily by 

 the earth. In cases of light or sandy soil, it is contended 

 by many that the heavier oils carrying more asphalt in 

 their composition are more desirable and more effectual 

 for the purpose. 



" It is a hard matter to give any definite figures as to 

 the cost of treating the roads, for the reason that con- 

 ditions differ and prices of material vary in the different 

 localities ; but from the figures given by some of our 

 supervisors it seems that it takes from 75 to 250 barrels 

 of oil per mile for the first treatment, according to the 

 character of the soil. About one-third of the original 

 amount is suflficient for the second year, and thereafter in 

 constantly decreasing amounts. It is stated that the 

 average cost, taking the first application and the later 

 attention, should not exceed 20/. per year per mile. It is 

 authoritatively claimed that treatment by oil is much less 

 expensive, even at the outset, than the use of water in 

 laying the dust, and at the same time is enduring." 



Mr. Lyle Rathbone, in a paper read before the 

 Liverpool Self-propelled Traffic Association this year, 

 gives an account of experiments with oil carried out 

 on the roads at Liverpool. The oils used were hot 

 a7id cold creosote oil bv itself, creosote I'il mi - >1 illi 



r flour at the Crystal Pala 



1 the Aulilm„b,U Chib Jon 



found after a heavy rainstorm' the road had not cut or 

 washed, but on a road in the same neighbourhood under 

 the same conditions not treated with oil it became 

 impassable. 



" The process of preparation varies considerably accord- 

 ing to the opinions and experience of the different workers, 

 as well as with the different material of which the road 

 bed is composed. Some otTicials have claimed that a very 

 sandy road w'ould not be benefited with oil, but by re- 

 peated experiment it has been found that by putting on a 

 very heavy coat of oil the loose sand has taken it up, and 

 by continual application a very fair road bed has been 

 made out of what was almost impassable sand. In some 

 instances sandy roads have been first crowned up with 

 a heavier soil or with clay, making a firm foundation, and 

 then treated with oil, thus making as good a road as in 

 other sections where the land is heavier. In some locali- 

 ties, where oil has been used for some time and careful 

 attention given to repairs and renewal, the roads have 

 become as smooth and hard as asphalt pavements and 

 without the disadvantage of dust. In preparing an 

 ordinary road, in some instances the surface has been 

 loosened by a machine carrying something in the nature 

 of a rake, for the purpose of being able thereby to mix 

 the oil with the surface dirt. In others where the soil 

 is heavy and packed hard, it has been covered with oil 

 and then a thin coating of light sand is sprinkled over 

 this, which causes the whole to cement together, forining 



small proportions of pitch, resin, or tallow respec- 

 tively, hot coal tar, cheap waste oil from coal tar, 

 common petroleum, and crude Te.xas petroleuin. The 

 general results do not appear to be anything like so 

 permanent as those obtained in America referred to 

 above. They were satisfactory as far as they went, 

 the tendency being for the road surfaces to be pre- 

 served, to dry more quickly, and to be cleaner. No 

 very conclusive result as to the best oil seems to 

 have been reached. Creosote oil with resin gave the 

 cleanest and best appearance, and ordinary petroleum 

 was the least lasting. Heavy coal tar waste oil lasted 

 longer than creosote, and was very much cheaper ; 

 a single coat kept the surface in good order for about 

 three weeks, and two coats for about five weeks. 



Experiments by the Scottish -Automobile Club 

 showed that crude oil was most effective. It was 

 poured on to the cleaned road surface by means of 

 cans, and brushed over so as to saturate the surface 

 uniformly. In about twelve hours the surface was 

 dry enough for traffic. The cost per mile of road of 

 fair average width was about 20/., which may seem 

 costly, but the method has the great advantage that 

 a single application is sufficient for a season, and 

 against this cost must be set a saving in other ways. 

 It is to be hoped that more extensive experiments 



NO. 1872, VOL. 72] 



