408 



LANDSCAPE GARDENING. 



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 order 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 surfaces 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 con- 

 duit pipes on a regular uniform slope, to secure a steady 

 uninterrupted flow of water. Owing to the friction in the 

 pipes, and 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 example, if the reservoir is ten feet four inches 

 high, the water in the jet will only rise ten feet, and in like 

 proportion for the different heights. The following table* 



* Switzefs Introduction to a General System of Hydrostatics. 



