,84 ROADS. ^, 



are requifite, fimilar mounds ought to be 

 formed, as guards to the shores or ditches 

 behind them •, openings being made at pro- 

 per diftances for the water coUedled by the 

 road. 



The CONVEXITY of a road ought to be 

 fuch as will throw off the rain-water which 

 falls on it, without endangering in any de- 

 gree 2. top-load. 



Before a top-heavy load can be over- 

 turned, the entire weight muft be thrown 

 upon the wheel or wheels of one fide ; con- 

 fequently the nearer it approaches to the 

 dangerous equipoifc, the greater injury the 

 road will receive. 



Thus, fuppole a loaded waggon to weigh 



two tons. Upon level ground each wheel 



\vould fullain half a ton-, but upon a flielving 



road, fleep enough to bring the load to the 



equipoife of overturning, the entire weight 



would reft upon two wheels only, each of 



which would in this cafe fuftain one ton ; 



confequently, if we reckon prefiure as in- 



*(ury, the damage done by a carriage at the 



point of overturning is twice as much as that 



which is caufcd by the fame carriage on level 



ground ^ 



