LECTURES AND ESSAYS. 383 



also seem to indicate that we are paying in extra cost of transportation over 

 poor roads, 'a tax which would do much toward building good ones. A 

 poor road is a toll collector that needs no gates to exact its dues. All who 

 pass over it must pay in diminished loads and extra time, a tax proportional 

 to its wretchedness. If the general public could be made to feel that waste 

 of time and waste of money are equivalents, and that extra time spent in 

 traveling over the roads could profitably be employed at home, some steps 

 would be taken that would lead to an actual improvement in the condition 

 of our common roads. 



If we conclude to improve our roads we must consider some important 

 points. 



DRAINAGE. 



The first and most important requisite is the drainage. No matter what 

 material you have at hand, no matter how carefully you may apply it, if your 

 road is constantly saturated with water, it will be a miserable failure. The 

 amount of water that the road will absorb without being injured, depends 

 upon the soil. Sandy roads are very much better when thoroughly damp- 

 ened, but if saturated they are as soft as the thinnest mud. Clay roads are 

 very hard when dry, and at this time present a surface which rivals the hardest 

 gravel. Were it not for the dust which rises from the surface of dry clay 

 roads with the least breath of air, they would be considered equal to our 

 best stone or gravel roads. A wet clay road, however, is an altogether dif- 

 ferent thing; the hardness which characterized the dry road is no longer to 

 be found, but in its place is a soft jelly-like mass, without a fixed surface, 

 and sometimes without any sensible bottom. 



A gravel road affords a ready means of escape for the water that falls 

 upon it, and consequently it is not so much improved by drainage, but when 

 thoroughly saturated with water it is much softened, and very much 

 injured. 



In all improved methods of road building, thorough drainage is the 

 important requisite ; it forms the first and principal operation in preparing 

 the foundation. The noted road builders of Europe all insisted on this one 

 thing. McAdam, the inventor of the broken stone roads, and Telford, a 

 man who much improved the roads of McAdam, both insisted on thorough 

 drainage of the foundation. 



The road surface is the only important consideration so far as the traffic 

 is concerned, for it directly receives the traffic, and forms the resisting 

 medium for our vehicles. It is important then that the road surface be hard 

 and smooth, every rut and every inequality adds both to the draft and to 

 the discomfort of riding. Again, the surface should be as hard as possible. 



It has been discovered both by theory and experience that hills increase 

 the draft by an added fraction of the weight of the load that is inversely 

 proportionate to the distance passed in rising one foot. That is, if the draft 

 on a level road of a certain character were a certain fraction of the weight 

 of the load, on a hill of the same character, the increase of the draft would 

 be an added fraction of the weight of the load, having one for its numerator 

 and for its denominator the distance, measured on the slope of the hill, to 

 secure one foot rise. 



Thus the added draft would be one-fiftieth of the. weight of the load, if 



