134 L. E. HICKS — SOME ELEMENTS OF LAND SCULPTURE. 



cuous; still the action of each single force is regular, exact and unvary- 

 ing, and the complex results are harmonious. 



Predominance of Curves over Angles. — Most pleasing to the eye are those 

 forms in a landscape which arc bounded by curved lines and surfaces. 

 Most striking, picturesque, rugged and impressive are those which are 

 hounded by planes and angles. The former arc far more common, and 

 are produced by weathering and the washing of water. The latter de- 

 pend upon the primitive structure of the rocks. Angular structural" 

 forms are the rough blocks which nature furnishes. Wind and frost. 

 sun and rain, rills and rivers, are the tools which carve out of these 

 rough blocks the beautiful landscapes which adorn the earth and make 

 it a fit abode for man. 



Structural Angles. 



Character of Rock governs Form. — The laws of structure are intricate. 

 and structural forms are infinite in variety. The planes may face in 

 any direction, the angles may be acute or obtuse. That depends wholly 

 upon the forces of upheaval and the laws of fracture in the different 

 rocks; granite, limestone, basalt, conglomerate, each imparts a definite 

 and characteristic expression to the landscape, because each breaks in a 

 way peculiar to itself. 



Incessant Activity of sculpturing Force*. — But with all this variety in de- 

 tail there are certain broad, general features of structure which exert an 

 important influence in the evolution of earth forms. The pent-up forces 

 within the earth thrust up from time to time fresh blocks, to be disinte- 

 grated by the weather and carved by running water. ' These sculpturing 

 forces never rest, while the forces of upheaval are intermittent. This 

 incessant and universal activity of the sculpturing forces is the reason 

 why the pleasing forms hounded by curves are more common than rough 

 structural angles. 



Flatness Characteristic of continental Blocks. — Though the internal forces 

 are inconstant they are mighty. Mountains and continents are the 

 burdens which they lift with ease. The lands are lifted and at the same 

 time broken, faulted, bent and tilted this way and that. The resulting 

 planes may slope north, south, east or west, and the pitch may be steep 

 or gentle. Very steep structural planes are. however, of limited extent, 

 while the great continental blocks must of necessity lie nearly flat, 

 though the edges may lie precipitous. Broad, flat blocks are therefore 

 the usual raw materials for the sculpturing forces, and the resulting 

 weather and water curves are dominated by these massive and nearly 

 level, primitive elements of structure. Massive breadth and relatively 

 slight inclination of the general surface are the fundamental character- 



