No. 144.J 535 



3. The relative condition of adjacent districts, and how far the 

 want of discharge in one district affects others. 



4. Whether the superfluous water in any particular locality 

 arises from springs, or whether it is rain water retained in the 

 ^oil. 



5. Whether water in sufl&cient quantity to be useful, could be 

 collected by drainage. 



6. The most suitable localities for reservoirs for collecting such 

 waters. 



To secure the salubrity of a residence the drainage should be 

 deep and close; its high value will enable the owner to bear a 

 large expenditure to secure the advantage. 



Sewers in cities are often constructed with flat bottoms ; this is 

 wrong; the water spreads, increases the friction, retards the flow, 

 ^nd soon accumulates a deposit ; with circular sewers the amount 

 of deposit is small in comparison. 



The smaller the quantity of water to be discharged, the greater 

 DUght to be the care in the concentration of the flow and in the 

 construction of the sewers intended for its conveyance. 



It has been found that pipes with the same diameter, exactitude 

 of form, was of more importance than smoothness of surface ; that 

 glass pipes which had a wavy surface, discharged less wafer at 

 the same inclination than clay pipes of exact construction. By 

 means of this exactitude, and with pipes of the same.diameters, 

 an increased discharge of water, amounting to one fourth was ef- 

 fected within the same time. Therefore, by a careful construc- 

 tion of agricultural or city drain pipes, the same effects may be 

 produced wi h pipes of less size than those in common use ; acca- 

 Tacy in the f.^rms of jointing is likewise indispensable. 



In respect to town drainage, the practice of architects and en- 

 gineers has been to enlarge the area of any main pipe in the pro- 

 portion of the sectional area of each junction into it ; whereas it 

 -has been found, that the addition of eight junctions, each of three 

 inches diameter, into a main line of pipe of only four inches di- 



