176 . ANNUAL REPORT 



The matter to be disposed of is conveniently separated into four 

 parts : 



1. Solid matter, not excreta, including sweepings, ashes, garbage 

 and litter. 



2. Excreta, i. e. faeces and urine. 



3. Foul waste, including house slops, and the waste of factories of 

 many kinds. 



4. Surface water. 



Let us eliminate the first and last elements. 



Of the first, solid matter, not excreta, the only thifig to do is to col- 

 lect and cart it off to some suitable place. As to its ultimate dispo- 

 sition I will speak farther on. 



Of the last constituent, surface water, it needs only to be said, that 

 it must be allowed to run off in drains, closed or open. Of late years 

 there has been a very lively debate between advocates of two systems 

 for disposing of surface water. One party clamors for a so-called 

 ** separate system " of drains, independent of the sewers. The 

 other party prefer to turn all rain water into the ordinary sew- 

 ers, enlarging their capacity accordingly. The " separate system " 

 has obtained considerable acceptance in London. 



For our purpose we need to remark that any attempt to utilize 

 water-carried sewage is immensely increased in difficulty if it is di- 

 luted with surface water. It is, I think, probable that the separate 

 system may come into extensive use on this account, but there are 

 those who question this. 



There remain for further consideration the other two constituents: 



Excreta and 



Foul water. 



Before the introduction into England toward the close of the six- 

 teenth century of the ancient Asiatic water closet, it was the custom 

 to remove excreta in wheeled boxes or tubs, and allow foul water to 

 run off in open drains. The formation of sewers was an afterthought. 

 The great Cloacae of the Romans, the huge original conduit of Paris, 

 the first sewers of London, were constructed to drain off e uperfluous 

 ground waters, those in particular of certain streams and swamps. 



When the slop waters of a city became voluminous and their dis- 

 charge in open drains intolerable it was a simple device to put them out 

 of sight by turning them into the great underground drains. A rapid 

 extension of lateral and tributary sewers was a natural consequence. 

 The introduction of water supply systems into modern cities has brought 

 the water closet into extensive use, and along with it the so-called 



