38 



LANDSCAPE DESIGN 



Islands 



Shores and 

 Beaches 



be formed by spurs of the surrounding hills connected with the back- 

 lying high land, and often running into the lake with an island or chain 

 of islands lying off their points where the original ground surface dips in 

 parts below the water. The bays, similarly, will be likely to be con- 

 tinued inland as valleys reaching into the surrounding hills. When a 

 lake is fed by a considerable river, the portion of the lake where the river 

 enters is likely to be filled with silt, and therefore to be shallow, sandy, 

 and with a shore of smoothly curving outline. 



If islands are water-surrounded hilltops in a lake, they may lie in 

 a series off a point, as we have said, or in some other way their location 

 and form may continue or repeat the modeling of the surrounding 

 land surface of which they once formed a part. If the islands are 

 sand deposits they will lie where rivers come into the lake or down 

 stream and to leeward of points. If the islands are in a river, they 

 will be either projecting rocks or other hard materials which have 

 remained when soft material was eroded around them, or they may 

 be sand bars, or perhaps remains of "ox-bow cut-offs" where the 

 river has shifted its course without entirely abandoning its old channel. 



Natural islands, then, are likely to have some ordered relation to 

 each other and to the shore, different according to their geologic origins, 

 making them often fall into very effective pictorial compositions. These 

 can well serve as suggestions to the landscape designer not only in his 

 shaping of water areas, but in his treatment of lawns and planting as 

 well. 



Though the main shape of a lake is usually the shape of its pre- 

 existing valley, the shape of the actual shore of a lake, at least of a 

 large lake and more especially of the sea, is the result of the action of 

 the wind-driven waves. 



Where a shore or bank is being cut away by wave action, if the bank 

 is composed of material of various sizes, as it probably will be if it is 

 river deposit or glacier deposit, the coarser material longer resists 

 the assault of the waves and protrudes from the finer material. If 

 considerable masses of coarser material exist, they will tend to form 

 promontories, between which the finer material will be cut back into 

 bays. Moreover, each material will have its natural angle of repose 

 in the bank where it is subject only to the under-cutting of the waves 



