DRAINAGE. 41 



not appear sufficiently large, nor should they be situated in 

 positions to admit any draught to the detriment of the horses, 

 an objection which has been raised by the advocates of covered 

 drainage. A good position for a gully is immediately inside 

 the wall, if this objection is seriously entertained. Major- 

 General Sir F. Fitzwygram, in his work, suggests that an open- 

 surface gutter should be carried, not less than 12 feet beyond 

 i'.s passage through the wall, before joining the underground 

 drain, and considers it acts as a sort of natural trap to prevent 

 solid matter from passing into the drains, and also keeps the 

 effluvia from reaching the stable (see Plate 56), but both these 

 duties should be performed by an efficient trap. The whole 

 length of the surface gutter being well flushed in washing, the 

 liquid should pass at once through the wall ; and, by means 

 of a syphon trap and pipe, as shown on Plates 8 and 9, reach 

 the subterranean system quickly. 



When open surface gutters are formed in the granite paving Granite open 

 of the passage, as in the tramway stables at Southampton, g^^^^^^'s* 

 however well the cubes may be laid, they should have a fall of 

 not less than i in 60, the gutter starting at a level with and 

 dividing its fall with the slope of the passage. 



Wrought iron surface gutters, having perforated movable Wrought iron 



covers, shown in Fisf. 1 0, are now much in use in stables where covered sur- 

 ' b Ji face gutters. 



open-surface gutters are objected 



to, but they are more liable to be ^^^* ^^' 



choked, and if left uncovered are 



dangerous to the horse; while 



those of cast iron are still less 



desirable, as they are more liable 



to be broken. The objection 



that the litter in open-surface gutters is not kept so dry is 



scarcely a vaUd one, since of the whole area of the stall, it is 



only the actual surface of the gutter itself (a small one), that 



will be especially dry, or dryer than it would be with an open 



surface of sufficient fall. 



