DRAINAGE. 



45 



Yard gullies may be made in the form shown in Fig. 22 Yard gullies. 

 of brickwork, built and lined with cement, having a 2-inch 

 York stone trap and cast-iron cover; or in stoneware up to 



Fig. 21. 



VENTILffTOn. 



Section fi.B 



•^.A 



- . /^ 



PLftM 



18 inches diameter. The former is best suited for a large yard, 

 where there is a considerable flush of water and a very small 

 percentage of soil conveyed by the pipes ; but for small areas 

 and general purposes, the stoneware gullies. Figs. 23 and 24, 



Fig. 22. 



Fig. 23. 



Fig. 24. 



manufactured by Messrs. Doulton, will be found most 



effectual. They can be obtained with outlets of varying sizes . 



The use of the syphon trap in some form or other, has Iron syphon 



traps. 



