STRUCTURES IN LANDSCAPE 217 



position. A very elaborate triumphal bridge carrying an unimportant 

 footpath is likely to appear as absurd as a great stone arch carrying a 

 highway over an insignificant rivulet. Unlike various structures which 

 we have before discussed, a bridge is not seen to best advantage from 

 the road or path which approaches it. If it be a covered bridge, or if 

 there be some kind of pylon on each side of the way at the end of the 

 bridge, there will be from the road a certain sense of an enframed en- 

 trance, to any one crossing the bridge, and the view up and down the 

 water from the bridge may also in some cases be similarly enframed, 

 particularly if the bridge is covered. It is in the views towards it across 

 water that the bridge assumes its real value as an esthetic unit in land- 

 scape composition. (See Plates 28 and 32.) Almost inevitably it is the 

 dominant object of an enframed composition with many lines converging 

 upon it. Frequently tall planting * on the shores from which the 

 bridge springs will pleasantly increase this enframement and give an 

 additional solidity to the abutment. It is never without its reflection 

 in the water, clear or blurred as the water surface may make it, and 

 the designer should remember that he is creating not the span of the 

 bridge alone, but also its inverted counterpart in the surface below. 



The shape of the bridge may be an arch or a series of arches, with Forms and 

 any degree of proportion of rise and span, or it may be abutment and Materials of 

 pier and gently cambered line of traffic-way over all, or exceptionally 

 it may be a spider-web construction of steel cables and suspended road- 

 way between two towers. All these shapes may be very beautiful. 

 Modern knowledge of the use of structural steel has produced many 

 other economically efficient forms as well. Many of them are in- 

 herently ugly; others we may learn to like, when our present knowl- 

 edge of the possibilities of steel has passed into a feeling for proportion 

 of parts as it has, long since, in the case of stone. 



The form as well as the material will probably be forced upon the 

 designer by considerations of cost, traffic, and local conditions. This 

 form, however, should not only be actually sufficient for structural 

 stability, but should appear to be so.f A bridge can be consistently 



* Cf. Planting in relation to bridges, Chapter IX, p. 187. 



t For illustrations of various bridge forms see H. G. Tyrrell's Artistic Bridge 

 Design. (See REFERENCES.) 



