398 LANDSCAPE GARDENING. 



exceed the area of the orifice of the conduit pipe. The ob- 

 ject is to prevent any diminution of pressure from the body 

 of water in the cistern, and to facilitate the flow of the water. 

 Where the conduit pipe joins the fountain, there, of course, 

 ouofht to be a cock for turninor the water off and on ; and 

 particular care must be taken that as much water may pass 

 through the oval hole of this cock as passes through the cir- 

 cular hole of the pipe. In conduit pipes, all elbows, bend- 

 ings, and right angles should be avoided as much as possible, 

 since they diminish the force of the water. In very long 

 conduit pipes, air-holes formed by soldering on upright pieces 

 of pipe, terminating in inverted valves or suckers, should be 

 made at convenient distances, and protected by shafts built 

 of stone or brick, and covered with movable gratings, in or- 

 der to let out the air. Where pipes ascend and descend, on 

 very irregular surfaces, the strain on the lowest parts of the 

 pipe is always the greatest ; unless care is taken to relieve 

 this, by the judicious disposition of cocks and air-holes. 

 Without this precaution, pipes conducted over irregular sur- 

 faces will not last nearly so long as those conducted over a 

 level." — Encycl. of Cottage^ Farm, and Villa Architecture, 

 page 989. 



Where the reservoir is but a short distance, as from a dozen 

 to fifty yards, all that is necessary is to lay the conduit pipes 

 on a regular uniform slope, to secure a steady uninterrupted 

 flow of water. Owing to the friction in the pipes, and the 

 pressure of the atmosphere, the water in the fountain, will 

 of course, in no case, rise quite as high as the level of the 

 water in the reservoir ; but it will nearly as high. For ex- 

 ample, if the reservoir is ten feet four inches high, the water 

 in the jet will only rise ten feet, and in like proportion for 



