ROAD ENGINEERS. 37 



fectly correct, being based on large actual experience, 

 though most probably at variance with the general 

 notions upon the subject. 



He preferred a bog to any other foundation for a 

 road, provided it would allow a man to walk over it, 

 as the resistance to the motion of a carriage would 

 ]iot be materially affected by the foundation if the 

 road was well made, and he mentioned a road which 

 shook when carriages passed over it, yet the con- 

 sumption of materials was less than on the limestone 

 rock in the neighbourhood. In the construction of 

 such roads he did not use any faggots nor any stones 

 exceeding six ounces in weight, and those sank iu 

 the bog, but united in one mass like a piece of 

 timber. 



As regards the wheels of vehicles passing along the 

 roads, he thought broad wheels less advantageous 

 than was generally supposed ; and he suggested that 

 the tolls might always be fairly assessed in proportion 

 to the number of horses employed, it being said that 

 their feet did more harm to the road than wheels ; 

 and he also suggested that waggoners should be 

 encouraged to harness their horses in pairs rather 

 than in a line one behind the other, which wore 

 a channel or pathway along the road. 



As might naturally be supposed, McAdam came 

 into communication with the London coach proprie- 



