THE OTAGO DAILY TIMES MONDAY, SEPTEMBER 1, 1913. THE ABOLITION OF MUD.

Otago Daily Times, Issue 15857, 1 September 1913, Page 4

THE OTAGO DAILY TIMES MONDAY, SEPTEMBER 1, 1913. THE ABOLITION OF MUD.

"Dust has been conquered; it does not exist in any appreciable extent on roads which have been properly treated with tar or bitumen." This assurance comes from no leas 'an authority than Sir George Gibb, who presided' over the third International Road Congress held in London in June last. Of . course dust and pud are twin nuisances on roads and city streets. If there were no mud there would be no dust, and vice versa, and' the prospect of the abolition of both would come as a welcome piece of news to those who so recently sanctioned the raising of a loan of £175,000 for the purpose of enabling the city officials to put our main thoroughfares in a condition that shall be above reproach. 1 As ah instance of the very widespread recopition of the necessity for "mending our.ways" it may ho pointed out that these congresses are held triennially. That of 1910 was held in Brussels, and the nest one,' in 1916, is to be in Munich. At tie London meeting 39 Governments were officially represented, and Mr Lloyd George, Chancellor of the Exchequer, who welcomed the delegates on behalf' of the British Government, said " there is not a civilised community in the world that is not represented' in this hall to-day." Probably he forgot the oversea communities in Australia and New Zealand, the former of which can supply bush dust 6torms scarcely less blinding than those common to the African deserts, and simooms that envelop -even city streets in du£ty darkness. The proceedings at this last congress of expert road makers and street constructors should be of practical valuo to Duriedin citizens in view of their project for the improvement of their streets, for it places at the disposal of the local authorities the experience of traffic experts frpm all parts of Europe. The concentrated attention that is now being given to perfecting road construction is almost entirely due to the development of motor traction and travelling. ' A report which -was circulated amongst the delegates at the congress stated that at' a given 6pot in the neighbourhood of London twenty years ago a few light vehicles and one or two heavy : carts would have passed along. Ten years ! later a stream of bicycles had taken > possession of the route, but on a recent i Sunday morning, at the same point, in ; a single hour, ' there passed 100 bicycles, < 50 motor bicycles, 50. motor 'buses, ,300 i motor cars, and 15 horee-drawn vehicles i These and similar facts have brought 1 about a revolution iii the matter of road < construction, and have almost obliterated { the distinction between urban and country J districts, in England /especially, iiut gone- , rally in the more thickly populatsd coun- « trios of Europe. To-day the neoeeaity for ( setter means of communication has in- t ;reased the demand for good roads, a£ t n the days of old. Before our era began s ,he Romans, in order to consolidate their c yide spread dominion, and to enable their i, egions to pass from one portion of the e impire to another, built roads, chiufly by t (WOTict and slave labour. Trawllars m s

the' Balkans to-day come across the Roman roads that extended as far east as the Persian Gulf. A record of the Roman invasion of Britain was left in the form of arterial roads that extended from Kent to Cardigan,'from St. David's in Wales to Tynemouth in the north and Southampton in the south, and from Cornwall to Lincoln. These roads were so solidly built as to be practically indestructible. They comprised four layers of properly chosen material, the third being concrete, on which was laid polygonal blocks of hard stone jointed with great nicety. British road 6, however, were almost incredibly bad up to the end of the seventeenth century, and remained in that condition until the days of Telford and Macadam, who, while their prinoiple6 of road con : struction were different, both insisted on thorough drainage as an absolute necessity. But even with all the modern theories of street and road construction the name of Macadam has entered into our vocabulary as a tribute' to his. genius more lasting than would have been the knighthooii which he refused to accept when it was offered to him.

Of late years other methods of street construction have come into vogue, particularly where traffic is heavy. Wood-paving was adopted as long ago as 1839 in England, but as soft-wood blocks were utilised, and proper foundations were not put in, unequal settlement brought these roads into disfavour. In 1871 an improved method of laying the blocks wa6 introduced, and Australian hardwood took the place of Baltic pine. A bed of sand was first laid, and inch-thick deal boards saturated with, tar were placed cross-wise thereon. The blocks were jointed with clean pebbles well rammed in, and then the whole surface was dressed with tar. As was the experience of the foolish man who built his house on the sand, the foundation gave wa,v when got below the blocks. The difficulty was solved by the substitution of cement concrete, for the foundation, on which hardwood blocks were laid with broken bonds, like bricks in a well. The blocks were passed through a tank of hot tar before being placed in situ, without interstices, and the whole surface of the street operated on was'finished off with a coating of tar and sand. This plan has been- found to answer very well in Melbourne and Sydney. Rival systems of street construction are to be found in the asphalt roadways kid down with Val do Traverse or with Trinidad asphalt. The latter material is largely used in American cities, where it gives great satisfaction to the road engineers. But the battle of road and street construction continues. Woodpaving, asphalt, and macadamising still have their champions, but, so far as can be gathered from the published accounts of the recent International Road Congress, the radical solution of the problem is to be sought in the adoption of improved methods and materials for construction, probably with bituminous binding or asphalt surfaces. Road engineers seem to be now of opinion that the wear of roads is produced, less by the contact of wheels rolling over them, than by the constant inter-attrition of the stones beneath the surface. This, wearing away creates fine particles that come to tho surface and form dust in, dry weather and mud in wet. Dunedin citizens are familiar with the proems of watering road metal when it has been recently laid, and then sending the steam roller over the newly-formed surface of the water-bound road. Sir George Gibb condemns this plan in toto. "Dust," he says, " does not exist to any appreciable extent on roads which have been properly treated with tar lor bitumen." What would he say if he saw road scrapings put on newly-laid metal for " binding? ' The proceedings at the congress brought out the fact that for the past two years English road engineers have obtained very satisfactory results from the use of what is known as " tarmac," that is to say, road; metal that has been treated with tar before being laid on the road, much' in the 6ame way as tar screenings are made at the present time in Dunedin. This reduces the inter-attrition to a minimum, for the ta,r binds the metal into a homogeneous whole, and is the warrant that Sir George Gibb relied on when he declared that " dust has been abolished."