106 LANDSCAPE-GARDENING 



unobtrusive and still allow its occupants to enjoy 

 the most delightful views over the water. \\hen 

 walls along the shore are really necessary, they 

 often can be constructed with bowlders placed ir- 

 regularly upon a slanting surface. When the ac- 

 tion of the waves is so strong as to make the use 

 of cement necessary, this material can frequently 

 be employed so it will not be seen by placing upon 

 it bowlders and gravel and planting shrubs or vines 

 just above it. 



The study of natural lakes will help in the con- 

 struction of artificial lakes and ponds. Natural 

 lakes have been formed by glaciers which gouge 

 out basins and then recede and leave glacial lakes, 

 or by rivers which change their course and leave 

 bodies of water in their former channels, or by the 

 obstruction of streams, or by any hollow land sur- 

 face which catches and holds water. The natural 

 water supply may be springs, streams, or merely 

 rain and melting snow. The features to be studied 

 are the general outlines, the shores and the border 

 growth. A lake becomes interesting when one por- 

 tion is hidden from another. The object which 

 separates the two portions may be a hill, a rise of 

 ground, or a growth of trees and bushes. The 



