BRIDGES — AMMANN 577 



ESTHETICS 



Besides the technical advance in bridge construction we may record 

 welcome developments with respect to the esthetic side. While engi- 

 neers generally are possessed of a strong sense of utility and are 

 inclined to justify the appearance of any structure from the economic 

 and scientific point of view, there is a marked recognition of the de- 

 mand of public opinion that proper esthetic treatment be given to 

 our public structures, and that the collaboration of the architect who 

 is trained and better qualified to develop esthetic forms and archi- 

 tectural embellishments is essential for that purpose. 



In large bridges, of course, the principal lines and proportions of 

 the structure must be determined by the engineer, for they are, to 

 a large extent, dictated by the fundamentals of strength and stability 

 and by local geographical and topographical conditions. Within 

 certain limits, however, the engineer must and can apply his own 

 sense of beauty in determining them. But it is often essential, in 

 order to improve the general appearance of a structure, to mask or 

 supplement certain crude engineering features by architectural em- 

 bellishments, the design of which must be left to the architect. It is 

 by such collaboration between engineer and architect that some of 

 our modern large bridges have progressed beyond the field of purely 

 utilitarian and scientific structures. 



