424 REPORTS ON THE STATE OP SCIENCE. — 1919. 



by to fill up the holes in the road and to make a firmer footing for man or beast 

 passing over. 



The fourth stage may be said to have begun with the coming of the wheel. 

 What suggested the use of the wheel first can only, be conjectured, but the rolling 

 of a log down a hillside, the ease with which a circular stone will jump over 

 obstacles may have been the germ of the idea, and when the wheel came every 

 road used by wheeled traffic began to assume a far greater imnortance. Probably 

 the earliest record of wheeled traffic is to be found in the Bible in the constant 

 references to chariots throughout the Old Testament, about 4000 years ago. 

 There is probably no record of wheeled vehicles older than this, for the most 

 ancient nations with which we are acquainted, the Assyirians and the Egyptians, 

 both used pack animals, horses, donkeys or camels, for crossing the deserts which 

 surrounded their countries. There was also much use of water carriage on their 

 rivers, such as the Nile, and the Euphrates and the Tigris which ran through the 

 midrlle of Egyptian and Assyrian territory. 



We may consider that the fourth stage in road development began in Roman 

 times, when towards the end of that Empire an elTort was made to make a road 

 of solid blocks of stone, such as we see in the still existing remains at Pompeii 

 to-day. The original track of some of these roads still exists to-day all over 

 Europe, as well as in this country. In those Roman days, roads were largely 

 influenced, as indeed thev have been in recent times in the case of manv 

 continental powers, bv. militarv considerations. For inetance. I'oads were made 

 in Roman times not alone valleys, but along the ridges of hills, in order that 

 the troops using them might always have the advantage of being on the higher 

 ground. There was also probablv an engineering reason for taking the roads 

 along the upland?;, in that the higher ground was the better drained, the less 

 liililp tn flood, and provided a firmer road bed. Instances of this characteristic 

 of Roman roads are to be seen in Watling Strept, which leads from the direction 

 of Edinburgh to the direction of Durham. This old road went over the summits 

 of most of the hills in betAveen. such as the Cheviots. Again, the old Roman 

 way betAveen Winchester and Silchester crossed some of the highest points of the 

 Hampshire Downs in a direct line. There are other roads on the Continent made 

 in a direct line, ignoring the desirability of better gradients, and refrainincr 

 from using valleys as the naturally graded means of access between watershed 

 and watershed. These Roman roads and their conseouential eifects formed one 

 of the most important direct results of Roman civilisation. This influence lasted 

 right through the earlier periods of European hist-ory. Through the Middle Ages 

 no particular attention was paid to roads for vehicles except when military 

 requirements were urgent. The use of pack horses was the rule ; roads the 

 exception. 



The fifth stage came when our ancestors floundered over roads which were 

 in winter often nothing better than semi-morasses. Thus thev remained until 

 the coaching era began, some 150 years ago, when the necessity for convey.ins 

 mails and passengers at what were considered then high speeds — an average of 

 eirrht to ten mile.=; ^^ hour — brought about revolution in road construction. 



'T'Vie sixth stage began with the work of Telford and Macadam in the middle 

 of the nineteenth century and their influence exists till to-day. It is a curious 

 and interesting fact that just when roads in 1830-40 were beginning to be put 

 into order and road traffic was coming into its own, and the earliest motor-cars 

 were beinsr tried, the railway era should at that moment have commenced. One 

 cannot fail also to see the modern parallel, when roads and transport upon 

 thpm are once more just reaching a very high state of development that a 

 ATinistrv compo.sed almost entirely of railway officials should have been allowed 

 by Parliament to control the future destinies of the roarl. 



Mai^adam's principle, which has stood the test of time, was that no broken 

 stone larger than could be passed through a 24-in. ring should be used in road 

 making. He also urged that there should be adequate foundation on which the 

 broken stone should be placed, that the whole should be consolidated by 

 rolling, and the road should be planned with a camber sufficient to drain its 

 surface. All these points were thought out and insisted upon by Macadam, 

 who may be justly called the pioneer and father of modem road engineering. 

 It is also interesting to note that it has lately been recognieed that the permanent 



