514 



On Draining. 



both for domestic and manufacturing purposes. And would not 

 such a supply be preferable, at least in idea, if not in palatable 

 reality, to that which so many of our towns now obtain by water- 

 works ; many of which receive their supply from the river after 

 it has passed the town. The consequence being that, in the 

 summer months, it might not require any very close calculation 

 to estimate the repetition of purposes and processes through 

 which each gallon passes in the eight and forty hours, however 

 disgusting the result might prove to the lovers of a pure beverage. 

 Were an area of country thus treated, that is, the land subjected 

 to a perfect course of drainage, and such portion of the water as 

 it was practicable to obtain applied to other useful purposes, it 

 would be found, after the heavy rains of autumn and spring which 

 now swell our rivers and brooks with water washed from the sur- 

 face and so thickly intermixed with the finer particles of the soil 

 as in its deposit to choke up the outfalls of the lower lands, that 

 it would pass off in a filtered and almost colourless condition, and 

 thus two important results would be secured ; — the best of the soil 

 would not be washed away ; and the water of the rivers would be 

 kept comparatively pure. 



And is there anything impracticable or even difficult in such 

 an application, under ordinary circumstances and with common 

 engineering skill ? The cost too in many localities would be 

 trifling compared with that at which towns often obtain their 

 supply by pumping from the river level. The same mechanical 

 means by which draining pipes are now made will mould clay 

 sewerage pipes of any form and dimensions ; and by having them 

 of a suitable substance, well burnt, and if necessary glazed, they 

 will bear a very considerable pressure. Pipes for the purpose of 

 sewerage are now being made with socket-joints and glazed, and 

 sold at 8d. per yard for 6 inches, and I s. lOd. per yard for 

 ] 2 inches diameter. In districts, however, where fuel is reason- 

 able, the clay suitable without glazing, and without sockets (which 

 I should much prefer for making a joint, as well as for other 

 reasons) these rates might be reduced. It is very common for 

 the Water- works of towns of 10,000 to 20,000 inhabitants to cost 

 from 20,000/. to 40,000/., for which of course the population 

 must pay a handsome equivalent impost in the shape of profit to 

 shareholders, as well as being subject to all kind of surveillance 

 and annoyance from officials and collectors. The average fall oi 

 rain in England may be taken probably at 25 inches a year, each 

 inch being equivalent to about 25,000 gallons per acre. Suppose, 

 however, that we estimate the available quantities at 20 inches 

 per annum and 20,000 gallons to the inch, we have a supply of 

 400,000 gallons a year from every drained acre of area from 

 which it can be collected ; therefore you will see that no very 

 excessive extent of surface is necessary for the abundant supply of 



