UNDERDRAINAGE 39 



and should not be shut off by trees. Vistas are designed 

 by a careful inspection of the topography and timber 

 growth. Free access should be had to all parts of the 

 park. This does not mean that access is to be obtained 

 necessarily by the construction of straight drives and 

 paths. Straight lines should not be used except in formal 

 architecture, where they may be entirely appropriate. 

 Many unsightly objects outside the park boundaries can 

 be hidden from the inside by the construction of border 

 mounds with suitable planting. These mounds are very 

 effective and are extensively used. 



THE ENGINEERING DESIGN 

 UNDERDRAINAGE 



Wherever soils are swampy or wet, underdrainage is 

 necessary. This can be accomplished in two different ways: 



First, by the laying of agricultural tile. Tile is made 

 in two patterns horseshoe and cylindrical. 



Horseshoe tile may be laid on a line of 1-inch boards or 

 else on the bottom of the trench if it is carefully graded. 

 The tile are frequently 2 feet in length. No coupling is 

 used, but a piece of cheese-cloth may be employed to good 

 advantage in wrapping the joints to prevent the entrance of 

 earth. 



Cylindrical tile come in 2-foot lengths and are provided 

 with 4-inch collars or rings to be used at the joints. The 

 sizes commonly used are 2-inch, 3-inch, and 4-inch. The 

 tile are porous and should be straight, hard and of uniform 

 cross-section. In draining lands they are laid in parallel 

 ditches joining the main at 45 degrees. Y-connections 

 can be purchased for the purpose. The distance apart 

 of the trenches, their depth and the size of the tile are 

 matters which experience only can satisfactorily decide. 



