December 26, [91! 



NATURE 



3 2 7 



1 these terms. The first great step has 

 been taken. In carrying the project out t<> a 

 successful finish, men of science must see to it 

 that the new organisations are not hampered by 

 conditions which in certain instances marred the 

 efficiency of former international organisations of 

 : similar kind. C. G. K. 



OUR ROADS. 



IN view of the generally accepted reconstruction 

 programme of rehousing our working popu- 

 ind providing small holdings for a large 

 number of the men from our lighting forces when 

 released from service, the question of our 

 loads and their extension to give access to the 

 proposed new factories, workers' houses and gar- 

 dens, small farms and allotments is of great inte- 

 rest, and has attracted much attention, several 

 papers dealing with this matter having been 

 recently read and discussed by the Institution of 

 Civil Engineers. 



k is evident that the transport facilities for col- 

 lecting and distributing goods into these trans- 

 formed rural districts must be such that the 

 country resident is as nearlj as possible on 

 an equality with the townsman. It is equally 

 evident that this distribution of goods cannot be 

 given by extending our railway system, whether 

 by branch lines of standard gauge or by narrow- 

 gauge feeders, as has been the case in France 

 and Belgium ; for, however much we extend a 

 railway system by light railways or tramways, 

 these can only collect and distribute produce up 

 to the point reached by the rails themselves, and 

 thus a railway system per se can serve but a 

 very small part of the land area. In fact, a well- 

 extended road system which connects every door 

 by road wagon is in a sense comparable with the 

 >ea, which connects every port in the world by 

 our ships. 



The future extension and improvement of 



■ ■I transport by road are, therefore, of first 



importance. It is interesting at this stage to 



r<\iew the work already carried out in road-surface 



improvement by the local authorities themselves 



or in cases where these authorities have been aided 



by the Road Board. A great deal was done in 



the improvement of road surfaces during the ten 



v. as immedtatel) preceding tin- war. Many new 



methods of waterproofing the surfaces, first by 



using coal-tar and pitch, and later on by bitumen, 



were tried on a large scale. Although we hear 



through the Press that our roads have suffered 



terribly from the war, and that the shortage of 



arid restrictions on the use of road materials, 



combined with the motor traffic, have resulted in 



aking-up of the road surfaces to such an 



that \ast sums will be required to put them 



• ' stati to .any the ini leased traffic which 



is expected during the reconstruction period, 



this is not true as 1 regards the improved roads. As 



a matter of fact, the improved road surfaces which 



NO. 2565, VOL. I02] 



had been developed previous to August, 1914, have 

 stood the severe strain of carrying the increased 

 war traffic remarkably well, for instance, if we 

 take the main road from London to Folkestone 

 as an example of one which has been daily 

 traversed by heavily laden trains of motor-wagons 

 1 arrving war material, this road has practically 

 had no money spent on it, its surface is as good 

 as it was at the commencement of the war, and, 

 what is interesting from a sanitary point of view, 

 it has been self-cleansing, the rainfall doing all 

 the scavenging that was necessary. Fortunately, 

 we have before us many similar examples of the 

 substantial correctness of the methods which were 

 developed just previous to the outbreak of war. 

 The damage on which so much stress has been 

 laid by the Press has been almost entirely confined 

 to the old, unimproved water-bound roads, which 

 must now be taken in hand. 



The newer roads, however, differ from the 

 older roads in one feature, i.e. that the use of 

 pitch and bituminous materials for binding the 

 road stone together has given an entirely new 

 aspect to the process of repairing and maintaining 

 our roads. The old water-bound roads wore out 

 by the material being ground away by the traffic, 

 when it was wetted by the rainfall, so that 

 the stones could move on one another, and instead 

 of remaining angular they lost their corners and 

 tended towards the spherical shape we see in 

 water-washed shingle. The pitch or bituminous 

 binding introduced reduced this wear to a 

 great extent, but in place of it introduced a new- 

 trouble : it was often the case in the experimental 

 work when pitch was used as a binder that the 

 roads were found to become corrugated by the 

 traffic ; harmonic waves were formed on their sur- 

 faces, and these waves could be levelled only by 

 breaking up the surface and relaying it — an ex- 

 pensive process. 



Road engineers are by no means unanimous as 

 to the causes of this wave formation. Some of 

 them blame the particular process employed for 

 preparing the material and finishing the surface 

 by rolling, but all have noticed the bad effect of 

 the synchronising or harmonic action of vehicles 

 passing over them, especially when the majority 

 of these are exactly of the same class, which is 

 the case when a line of motor-omnibuses begins to 

 work on a road previously traversed by hetero- 

 geneous traffic. It is unnecessary to dwell on this 

 point, nor is it important, for it is certain that 

 corrugation or wave formation always results from 

 the rolling action of wheels on any surface, even 

 of hard steel wheels on steel rails, as is shown 

 by the corrugation of railway and tramway 

 rails. 



The study of the harmonic effects of Wheels roll- 

 ing over surfaces of varying degrees of rigidity 

 and elasticity is a large and very interesting ques- 

 tion which cannot be discussed within the limits 

 of this article. It is more important to know what 

 can be done to limit its effect on road surfaces. 

 During the years of the war the question has 



