TRANSACTIONS OF SECTION O. 787 



and in addition to aeeing the old industries revived, we sliall have opened up au 

 enormous tract of country for new industries wliich at present is devoted 

 aoli'ly to agriculture. 



The pressure general at ITeathlield varies from lo-i lb. to 200 lb. per .s'lnare 

 inch. As to the permanency of the gas, I may state tbat in Ohina natural g;is — 

 from identically similar geological formations — has been used for evaporating salt 

 for over one tliousand years. 



The United States have some eleven thousand wells bored ; we have at present 

 nine, and are in course of sinking ten others. 



The comparison of gaseous fuels is approximately as follows : — 



Per 1,000 cubic feet at 40° F.) and at Atmospheric Tressxrck 



Natural gas 1,100,000 units of heat 



Coal gas 735,000 „ 



Water gas 323,000 „ 



Producer gas (heated) .... 156,000 „ 



WJSBWRSBAY, SEPTEMBER 16. 

 The following Papers were read ;— 



1. The Effect of Traffic mid Weather on Maeadamined Roads, and ih& 

 Prevention of Dust, lly T. AiTKEN, Assoc. M.Inst.CE. 



This paper deals with the problem of improving the structural condition of 

 macadamised roads to withstand the effect of weather and the ever-increasing 

 fast vehicular tralHc, esjjecially that of motor cars. 



After describing the methods followed in connection with the making and 

 repairing of macadamised roads, tlie author deals in brief with the principal 

 points to be observed when first-class work is required. The quality of the" 

 metalling (embracing the trap rocks generally, but more particularly basalt, 

 andesite, felsite, diabase, and some dolerltes, beiug very much superior and less 

 greasy in wet weather tlian limestone and most granites). The binding material 

 is specially noticed, and also the ell'ect of weather and traffic is described. 



The smoothness of macadamised roads when properly made compares favour- 

 ablj' with street pavements as tested by the viagraph. It is also pointed out 

 that macadamised roads begin to wear at a comparatively early period after being- 

 repaired. The causes of this are stated and the probable remedy, so as to ensure 

 greater cementitious power between the component parts of macadamised roads. 

 It is specially pointed out that the binding and not the metalling should be 

 treated, and preferably after the road has been repaired, when contour and surface 

 are at their best. Different methods, recently carried out, of treating mac- 

 adamised roads with petroleum or tar are mentioned, and the author describes 

 a method by which tar in its natural state can be applied to a road surface In 

 the form of a fine spray, under pressure, the penetration into the binding being 

 from 2 to -4 inches. The experiments carried out show a decidedly improved 

 surface, but adverse climatic conditions, extending for a considerable time past, 

 have precluded information of a reliable nature being recorded. It is pointed 

 out that the time has fully arrived for further improving the structural condition 

 of macadamised roads, and it is to be hoped that the methods adopted and 

 described in this paper will tend in that direction and prove successful. 



2. Fendulum Aijparattis for Testinq Steel as regards Brittlcness. 



By E. G. izoD. 



The ability of materials in general and steel in particular to withstand shock ia 

 a subject of great Importance to all engineers, and this paper gives an outline of 

 the systems generally in use for carrying out brittleuess tests, with remarks ou 



3 e2 



