184 On Draining. 



6. Miscellaneous Advantages. The drainage of one tract 

 of land, may likewise furnish water, by which the accommo- 

 dation of another may be promoted, for various useful pur- 

 poses, as, for irrigation ; for mills, and other machinery ; 

 for supplying houses, ponds, inclosures, canals, or artifi- 

 cial navigations. By peculiar modes of applying the arts 

 of draining also, the quantity of water found in mines and 

 quarries may be diminished, either by cutting off the re- 

 sources above, or by letting down that which often impedes 

 their working into a porous stratum below. 



On the whole, there are no means by which the value of 

 land can be advanced, or from which, when usefully ap- 

 plied, so many advantages can be derived, at a moderate 

 expense, as that of draining. The owner is benefited by an 

 increase of rent; the occupier, by that of produce; and the 

 public, by being thus supplied with greater quantities of the 

 most essential commodities, and by having a source of use- 

 ful employment furnished to the labouring classes of the 

 community. Unfortunately, in all parts of the United King- 

 dom, a great deal of land stands more in need of draining 

 than of manuring ; and there are very few districts, where a 

 knowledge of this essential means of improvement, is so ge- 

 neral, or so perfect, as it ought to be, 



2. On the Causes of Wetness in Land. 



To proceed with any prospect of success in the art of 

 draining, it is necessary to ascertain the causes which pro- 

 duce wetness in land, and the different appearances which, 

 according to soil and situation, it assumes. These causes 

 are, 1. Surface-water ; 2. Soils absorbing and retaining a 

 superabundant quantity of moisture, either from their own 

 texture, or the quality of their subsoils; 3. Land springs 

 from surface-water; 4. Springs from subjacent water; 5. Back- 

 water from ditches or ponds ; and, 6. Floods from rivers, 

 lakes, or the sea. li ! 



1. Surf ace- Water. On clay soils, wetness is commonly pro- 

 duced by surface-water. These soils are of different kinds, 

 varying both in their colour and texture ; but they all pos- 

 sess, in a greater or smaller degree, those adhesive qualities, 

 which retain the water that falls upon the surface, until it is 

 either drawn off by art, or exhaled by the sun and the at- 

 mosphere. Such soils, therefore, can only be relieved from 

 superabundant moisture, by surface-drains. 



2. Absorbing Soils. Loamy soils absorb water freely, and 



