PROCEEDINGS OF THE BOARD OF REGENTS. 349 



It remains for the committee to propose some method by which these evils may- 

 be remedied. 



The old, thickly populated cities and towns of Europe have been compelled, 

 for self-preservation, to expend millions of money, and adopted a variety of sys- 

 tems to remove excrement from the limits of their abodes. 



The systems last adopted for Paris and London, at an immense outlay, give in 

 general the main reliable features of the most acceptable plans. 



In Paris metallic vessels for every family are so arranged that the solid faeces 

 are sepai'ated from the urine. The latter passes into street sewers of large 

 dimensions, conducting it, with the surface drainage from tho streets, into the 

 Seine, and the solids are removed from the dwellings by scavengers with carts, 

 and conveyed some miles from Paris, where it is converted into dry poudrette and 

 sold for manure. No less than 278,000 cubic metres of these solid excrementa 

 were collected from the tenements in Paris and removed to La Vilette for con- 

 version into fertilizing matters in one year. 



In London a system commenced in 1859 of sewers at different levels, running 

 parallel with the Thames, receives all the house and street drainage, both solid 

 and fluid, and conducts the same, miles below the city, into the river, to find its 

 way to the sea. These longitudinal sewers drain the entire city surface of 117 

 square miles, and are together S2 miles in length. Their fall does not exceed 

 two feet per mile, and are carried over rivers, railways, roads, and streets, by 

 wrought-iron aqueducts. Of the surface thus drained 25 1 square miles are below 

 the level of high water, and drained by a sewer of 10 miles in length. A part 

 of the sewerage, or 14 J miles of this surface, has to be pumped up 17 J feet to 

 discharge it into the Thames; and at what is called the Abbey Mills Station, the 

 whole mass of sewage is pumped up 36 feet to the level of the outfall sewei\ 

 This system is peculiar in having culverts parallel with the river, to receive the 

 sewage at high levels as far as practicable, and not allow it to fall into basins or 

 valleys below tho river surface, and by steam pumps raising all the sewage mat- 

 ter from surfaces below tho river level into the main drains leading to the river. 



Another system is advocated, by which all the excrementa is received from the 

 water-closets, both solid and fluid, into small boxes in the streets, from whence 

 it is drawn by pneumatic portable' engines into tight barrels, and thence in its 

 liquid state distributed in drills underground by ploughs, as a manure lor the sur- 

 rounding country. It is claimed to be the only effectual way of removing this 

 offensive matter and preserving tho whole of it for manuring the soil. 



With subsoil ploughing, rotation of crops, lime, marl, green sand, barnyard 

 manure, guano, and other fertilizers, the use of sewage matter is not likely to be 

 acceptable to our agriculturists, and no demand will probably exist sufficient to 

 absorb the quantities that by this system must be daily disposed of in summer 

 and winter. 



The committee has come to the conclusion that we must construct the sewera 

 of the city of Washington on levels above high icater, and conduct them to dis- 

 charge their contents in the strong ebb current of the Potomac river at high ivater, 

 that the entire accumulation of twelve hours may have six hours of ebb tide to 

 carry it towards the Chesapeake, which, with the annual freshets and constant 

 flow of the Potomac, will always carry it beyond tho distance it can be brought 

 back by the flood. 



It is indispensable the outlet of these main sewers should be below the Long 

 bridge, (and as distant as practicable,) otherwise all the solid matter would accu- 

 mulate on the shoals between this bridge and Georgetown, and in time create as 

 great an evil as the canal. 



To effect this object all the main sewers must be carried across tlie site of tlie 

 present canal on closed aqueducts or causeways, at the most advantageous levels 

 above high water, and thence under the grounds south of the canal, to suitable 

 places on the bank of the river, where closed and covered reservoirs may be con 



