96 



THK ARCH. 



in tlio best examples a marvellous display of great taste and. 

 boldness of construction, where the cultivated eye may ob- 

 serve that the arch thrusts are all admirably accounted for, 

 and that the intermediate groinings are carried by slender 

 and lofty columns, all beautifully proportioned to the pres- 

 sures or loads they have to bear. 



Doubtless this amount of skill was only arrived at gradu- 

 ally, and through numerous failures in the first instance, or 

 by what has been called trial and error ; but the exquisite 

 taste of the old architects has been displayed in bringing 

 these noble structures to the perfection we now witness 

 and admire. 



In every structure, we may take it that suitability to its 

 object and surroundings is the chief element of stability 

 as well as of beauty. As wo indeed find it throughout 

 Nature : everything there is most suitable to its purpose, 

 and everything also most beautiful to the eye. 



Thus, in arches, a lofty arch of com])arativoly small span 

 is most suitable in a lofty building like a church, where 

 top weight has chiefly to be borne, as it is also the most 

 beautiful ; but under a flat roadway an arch of wide span 

 and small rise is by far the most beautiful as well as the 

 most fit for its purpose. The arch should be of the true 

 curvature due to its natural equipoise, as is explained fur- 

 ther on, and as is also exemplified in the roadway bridge 

 by its suspended counterpart — a suspension bridge — where 

 the natural and graceful curve of the chains always forms 

 its chief beauty. T^astly for a tunnel, the semi-circular 

 curve is the fittest and looks the best, because it has to sup- 

 port heavy pressure all round. 



The Gothic architects of old, without doubt, displayed 

 the greatest taste in their structures, in providing against 

 the disturbing effect of the horizontal thrust of their lofty. 



I 



