EXCESSIVE RAINS 



49 



The judgment of the engineer in placing the curve on the 

 diagram is aided chiefly by a study of the possible damage to 

 be done by a storm so great as to overflow the sewers and 

 fill the basements, injuring whatever may be housed there. 

 Evidently, if a sewer capable of taking care of the largest storms 

 known should cost $25.000 more than one sufficient only for 



1. Kuichling 



2. Talbot 



3. Sherman 



4. Gregory 



5. Sherman 

 & Taltot 



7. Duryea 



8. Gregory 



9. Gregory 

 10. Bering 



Duration of Rainstorm in Hours 

 FIG. 12. 



the maximum storms coming once a year, the cost of the 

 occasional damage due to infrequent rains must not be less than 

 the accumulated interest on $25,0x30 or the larger sewer is not 

 worth what it costs. Mr. E. W. Clarke of the Board of Public 

 Water Supply of New York City says * that the extent to 



* Engineering News, Vol. XL VIII, p. 388. 



