330 



STABLES 



underground tank, and in this manhole an intercepting trap must be 

 placed to prevent foul air from the sewer or cess-pool from entering the 

 drains. To ventilate the drains an opening for air must be formed in this 

 manhole, and at the head of the drains a drawn lead or cast-iron ventilating 

 pipe not less than 3\ inches in diameter must be carried up the building 

 outside. These are shown in fig. 476. 



The chief features of a stable trap are that it should be very strong, 

 and afford a good foothold for horses, and that the attendant should be 

 able to get his hand into every part. If by any accident it should be left 

 open, the horse should not be likely to be injured if he put his foot into it; 

 the trap should also provide as easy a flow for liquids as is compatible with 

 a sufficient water-seal. Winser's stable trap, shown in figs. 474, 475, 

 p. 85 of this volume, fulfils these conditions, and contains a perforated 

 metal basket which prevents straw and dung from entering the drains. 



Intercepting Tank. — Some corporations do not allow any connection 

 between stable-drains and the public sewers, and an intercepting tank may 

 sometimes be required. This tank should not be too large; it should be 

 impervious both at the sides and bottom; the top should be closed with 

 air-tight cast-iron cover, and due means should be taken for ventilation. 

 Such a tank, however, must be viewed with more or less suspicion, and 

 perhaps the safest way is to place it in a spot as little frequented as 

 possible, with a ventilating grid made to lift easily, and to have it cleaned 

 out at very short intervals. 



VENTILATION 



The ventilation of the stable is of supreme importance, as probal)ly 

 one-half of the diseases from which horses suffer may be traced directly or 



indirectly to defective ventila- 

 tion. The method found most 

 satisfactory is by the intro- 

 duction of a small glazed ven- 

 tilator (fig. 578) in the stable- 

 wall, as high above the horse's 

 head as possible. The fresh 

 air, being thrown upward to- 

 wards the ceiling, carries the 

 air as heated and contami- 

 nated by the horse's breath towards the back of the stable. From this 

 one or more shafts should be provided, according to the size of the stable, 

 but at least one to every three or four horses, up through the loft, and 



¥\g. 578. — Combined Window and Air-inlet 



