10 THE TONER LECTURES. 



of wide areas of its soil, than to the more offensive emanations of 

 the sewer catch-basins and the odorous nuisances which still exist. 



As a rule, in my judgment, the damp lands of the city should be 

 drained by an independent system of pipes entirely disconnected, 

 except at their outlets, with the sewer system. It is usual, I know, 

 to leave, purposely or accidentally, sutficient openings to secure the 

 admission of soil-water into the sewer, and so to effect a rude and 

 incomplete, but still valuable, drainage of the ground. Efficient 

 drainage of the whole area cannot be secured by this means, even 

 were it not, as it certainly is, extremely objectionable, for the reason, 

 among others, that a sewer which will let ground-water into the 

 conduit in wet weather, will let sewage matter into the ground in 

 dry weather, adding an important and foul contribution to the 

 organic matter which the earth is already charged with destroy- 

 ing ; and adding to the danger of tainting the ground-air, with 

 which the atmosphere about our houses, and especially the atmos- 

 phere of our cellars, is in free communication. 



No scheme for the sanitary improvement of Washington can be 

 considered even tolerably complete unless this very simple matter 

 of the thorough drainage of the soil is duly and skilfully provided 

 for. 



In the construction of new work much may be accomplished by 

 laying agricultural draining tiles in the same trenches with the 

 sewers, but ordinarily more than this will be necessary, and it is 

 always especially important to establish such a relation between the 

 subsoil drains and the sewers, where the latter must serve as out- 

 lets for the former, as shall fully protect the drains against any 

 inflow or regurgitation of sewage matters, as these might readily 

 escape from the tiles into the ground. 



"We come now to the question of the sewerage of the city — that 

 is to the means by which the twenty-odd million gallons of water 

 poured into it daily by the water-works, much of which serves 

 as a carrier for household and manufacturing wastes, is to be got 



