54 



PARKS 



STOP 



HINGED LIDS TO 

 O.OSE AUTOMATICALLV 



connected, then the house-connections lead to a common sewer which in 

 most cases will drain directly to the place of disposal or to the treatment 

 plant. Vitrified clay pipe is usually used for the common sewer, which should 

 be not less than eight inches in diameter. The house-connection pipe is 

 joined to the common sewer by a Y branch. All joints should be cemented 

 and made water-tight. All house-connections should be laid on a minimum 



grade of 1 140 in order that de- 

 posits may be prevented. The 

 velocity of the flow in a common 

 sewer when running one-half full 

 should be not less than two and 

 one-half nor more than eight feet 

 per second. Manholes, or inspec- 

 tion holes, should be placed at 

 turns in the sewer line, or every 

 three hundred feet if the sewer 

 is straight, in order to facilitate 

 inspection and cleaning. 



In order to be efficient and 

 economical in operation, flush 

 toilets must be of good construc- 

 tion and correctly installed. The 

 construction of the toilet build- 

 ings will vary according to local 

 circumstances, but whatever the 

 design may be they should be 

 fly-proof, well ventilated, easily 

 cleaned, and conform to the local 

 health laws and regulations. One 

 seat should be provided for every 

 five to ten people, but where the 

 question of expense is of impor- 

 tance this may be reduced to one seat for every ten to twenty persons. Sep- 

 arate buildings must be provided for men and for women, and the individual 

 seats should be separated by partitions. 



Sewage treatment. The excreta collected by toilets should be promptly 

 disposed of in such a manner that it will not endanger the health of man or 

 create a nuisance. It is highly putrescible and must be regarded as con- 

 taining disease-producing germs. The object of sewage treatment is to 

 convert the unstable and readily putrescible organic material into stable 

 and non-putrescible substances, and to prevent the transmission to man of 

 any disease-producing germs which it may contain. 



PLATE No. 331 

 ARMY TRENCH LATRINE 



Built without partitions between the seats. Suitable for 

 boys' camps. 



