SANITATION 



63 



Neech* who rightly condemns the practice of emptying the filth 

 on to the streets where it is only partially cleaned up and where 

 the remainder on drying is blown into the air and into the windows 

 of houses; it does not appear at present, however, that anything 

 can take its place owing to the amount of sand and similar debris 

 that gets washed into it. 



As the object of a gully trap is merely to prevent much solid 



FIG. 26. A Double-Seal Gully 

 with sediment pan. 



FIG. 27. Linton's Gully Top 

 with low back syphon trap. 



matter from entering the drain, all that is required for this purpose 

 is a suitable grating to an ordinary self-cleansing syphon trap for 

 use in stable yards and similar places. The author, in co-operation 

 with Mr. Dorsie, with this idea in view designed the trap here 

 figured which has been manufactured by Messrs. Cameron and 

 Roberton of Kirkintilloch. 



A form of trap at one time in much favour for use in sinks, 

 court-yards and other places to trap 

 surface water or slop waste is 

 shown in figure 28. This is the 

 Bell trap. It is made in two pieces, 

 a lower part which is the water con- 

 tainer, and an upper part which is 

 the inlet grating to which is attached 

 a lip in the form of a bell or inverted 

 cup which dips into the water con- 

 tained in the lower part and so forms 

 a seal. It is a very dangerous form 

 of trap and should never be used. 



FIG. 28. Bell Trap showing the 

 deposit of organic matter. 



Its most obvious disadvan- 

 tages are : the seal is too shallow ; the lip being attached to the 

 grating, the seal is broken each time the grating is removed for the 

 purpose of cleaning the trap and sewer gas can then pass freely into 

 the air; it becomes very easily choked; owing to the shallowness 



* The Insanitary Gully, Journ. Roy. San. Inst., Vol. XXXVII., No. 3, 

 Sept., 1916, p. 141. 



