UPPER INDIA. 33 



The more remote artificial causes have been at work for 

 such ages, and their results have become so extensive, that 

 they are generally regarded as natural causes, and it is not 

 uncommon to hear the terms natural drainage and surface- 

 drainage used as if synonymous, showing that all surface- 

 drainage has now come to be considered as natural drainage. 

 The more remote causes of surface- drainage are so spread 

 throughout the country, and are so extensive, that any 

 attempt to grapple with them would be futile at present. 

 It will be time to look after them when the more immediate 

 causes of surface-drainage have been modified. The more 

 immediate causes of surface- drainage are numerous and must 

 be separately considered. 



Roads are one great cause of surface- drainage. They act 

 in this way. The ordinary unmetalled road soon gets worn 

 into ruts by the action of cart wheels, or men or cattle passing 

 over it. In the dry weather the loose dust is blown away from 

 the roads, and their level is lowered, the rain falling on the 

 land on the sides of the roads finds its way to them, and they 

 become the drainage channels of the country. In some cases 

 attempts are made to rectify this by digging continuous 

 drains on both sides of the roads, and throwing the soil dug 

 from them on the roads to raise them. The rain then falling 

 on the road and on the land on both sides of the road, finds an 

 exit by the ditches, and they instead of the roads become the 

 drainage channels of the country. Eventually both the road 

 and the land on its sides are washed away and become ravines, 

 these spread, eating back their .way into the surrounding 

 country, which thus becomes useless for cultivation. The 

 metalled roads are generally somewhat raised above the level 

 of the country, the soil to raise them being taken from con- 

 tinuous drains by their sides, which, as in the case of the 

 unmetalled roads, become the drainage channels of the country 



