DRAINAGE 



329 



whole of the channel (fig. 471). By discharging the waste water from the 

 drinking-pot into it the flushing of the channel is rendered easy. Some 

 persons prefer an entirely open gutter (fig. 470), as being less liable to 

 choke up from neglect. The chief objection to open gutters is that 

 they allow the liquids to be absorbed by the bedding, retaining them 

 within the stable and vitiating the air. Musgrave's pattern, as shown 

 in fig. 577, has a fall in itself, and is often used; the channels or corru- 

 gations provide for the flow of liquids to the drain, while the surface is 

 almost level, and offers a good foothold for the horse. 



The underground drains should be made of glazed stoneware or 

 cast-iron pipes, laid upon concrete and jointed in the best modern manner. 

 It used to be the idea 

 that, on account of 

 the great percentage 

 of solid matter con- 

 tained in the drainage 

 from a stable com- 

 pared with the liquid 

 portion, a very large 

 diameter of pipe was 

 necessary. The theory 

 of large pipes for 

 house- drain age is now 

 quite exploded, and 



there is no reason why it should be retained in the case of a stable. 

 The contrary rather should be the case, for a small pipe running nearly 

 full will be better flushed, and there will be less deposit of sediment 

 than with a larger one. 



The same arrangements must be adopted for stable drains as for house 

 drains. All inlets to the drains ought to be outside the building, as shown 

 in fig. 574, and ought to be trapped. The trap shown in fig. 475 can be 

 used for this purpose. The surface drainage from the stable ought to be 

 carried through the wall by an iron pipe discharging over the basket in the 

 trap, and to prevent to some extent the risk of foul air being drawn through 

 the pipe into the stable, a hinged brass flap (fig. 473) may with advantage 

 be fitted on the outer end of the pipe. It is desirable to have an inspec- 

 tion-manhole with an air-tight cover at every change of direction or 

 important junction, so as to obviate as far as possible any necessity for 

 lifting the drains and breaking up the yards and pavement. Another 

 manhole must be constructed at a short distance from the point at which 

 the drain is connected to the public sewer or to the private cess-pool or 



Fig. 577. Musgrave's Patent Open Surface-gutter 



