PROCEEDINGS OF SECTIOX H. 651 



4.— THE MAKING AND MAINTENANCE OF MACADAMISED 

 ROADS WITH A VIEW TO THE PREVENTION OF DUST. 



By J. VICARS, M.C.E., City Engineer of Adelaide, South Australia. 



It is customary, though not strictly correct, to refer to all broken 

 stone road pavements as macadam, of which the various systems 

 introduced by others are considered as varieties. This classification,, 

 though not as scientific as could be desired, is nevertheless convenient, 

 and will be adopted in this paper. 



The historical aspect of broken-stone roads is, perhaps, more, 

 interesting than serviceable, unless, indeed, its chronicle supplies a 

 beacon warning against the Scylla and Charybdis of road-making — 

 rocks where they are not Avanted. As there are so many lengthy 

 accounts of the early efforts in this direction, only a brief summary 

 of the salient epochs will here be attempted. 



It has been wittily stated that the first roads known to man were 

 of the nature of in-roads. It is, however, safe to say that primitive man 

 knew no roads, in the sense under consideration, and therefore no 

 pavements. Before his existence iii communities his house was a 

 tree or a cave, and his home and occupation the forest and the chase. 

 As time wore on the tribal tracks became paths ; and after the lapse 

 of many centuries the interchange of commerce, at the dawn of 

 civilisation, developed trade routes. 



Perhaps the first attempt at a paved surface emanated from 

 tribes which had ceased to be nomadic, and where the frequent use of 

 a track made the employment of gravel or burnt clay essential to its 

 existence. 



Some authorities contend that the transport of armies first induced 

 the construction of paved surfaces ; but from our knowledge of semi- 

 barbarous peoples, it would almost seem certain that roads of a kind — 

 even the approach or the clearing of a track through a wood to some 

 drinking place — came into existence when tribes still fought in bands 

 and made their onslaught secretly, without the lengthy warning 

 necessitated by the making or paving of tracks for that purpose. 



Then it may reasonably be conjectured that with the evolution 

 of our race from one age to another — from the Stone age to the Bronze 

 age, at latest — man, with increased intelligence and means at hand, 

 broke down stones to form the first real pavement. 



By pavement is meant a surface of material artificially prepared, 

 as opposed to one formed of materials as found in nature, such as a 

 layer of gravel. Owing to the absence of the material necessary for 

 the preservation of such records, and the non-existence of written 

 language, the pages in this past history of mankind and his works 

 are unfortunately a blank, and we now can only conjecture and reason 

 deductively from the evidence of other less perishable remains which 

 have from time to time been brought to light by the archeologist and 

 traveller. In these matters it is established beyond doubt that negative 

 evidence is no proof of the previous non-existence of such works. 



