222 STATISTICAL SURVEY 



impoffible to unite permanence of furface with perfect 

 flatnefs, a more practical form muft be fought. All, 

 therefore, that can be done, is to endeavour to hit the 

 happy medium ; to raife the furface, until a degree of 

 roundnefs be gained, fo as to render the fhape, though 

 not perfect, yet fufficiently convenient to anfwer fully 

 the general intention. The requifite degree of round- 

 nefs varies with circumftances, depends on the given 

 fituation, the given materials, and the width and pub- 

 licnefs of the road ; the fteeps and levels more particu- 

 larly ought to be kept as round as perfeft conveniency 

 will permit ; for the quicker the rain water efcapes off 

 the former, the lefs mifchief it occafions, and the 

 quicker it efcapes off the latter, the more good. 

 Wherever a road is obferved to keep itfelf free from 

 (landing water, and inequalities of furface, in a wet 

 feafon, and this where the form is not too round for 

 convenience, every part of it being travelled over, the 

 happy medium has been hit and preferved. Roads, 

 bearing this teft, are proper fubjefts of iludy for road- 

 makers, rather than any theoretic rule that could be 

 offered j except that a degree of roundnefs is requifite 

 in all feafons, and in all fituations. By giving this fhape 

 to roads, and by preferving it with due attention, fo as 

 to keep them free from water, and, in a continuance of 

 wet weather, from a fuperfluity of reduced materials, 

 which form the mud ; and by clofmg the ruts, and 

 filling the breaches as foon as they appear, a confide- 



rable 



