AKCHITECTURE OF THE SKULL 



19 



unless that part of the arch which springs from 

 the pier yields ; and in all arches, from the imper- 

 fect Koman arch to that built upon modern prin- 

 ciples, the aim of the architect is to give security 

 to this point. 



In the Roman bridges still entire the arch rises 

 high, with little inclination at the lower part ; and 

 in bridges of a more modern date we see a mass 



o 



of masonry erected on the pier, sometimes assum- 

 ing the form of ornament, sometimes of a tower 

 or gateway, but obviously intended at the same 

 time, by the perpendicular load, to resist the 

 horizontal pressure of the arch. If this be omit- 

 ted in more modern 

 buildings, it is sup- 

 plied by a finer art, 

 which gives security 

 to the masonry of 

 the pier (to borrow 

 the terms of anat- 

 omy), by its internal 

 structure. 



In what is termed 

 Gothic Architecture, 

 we see a flying but- 

 tress, springing from 

 the outer wall, car- 

 ried over the roof of 

 the aisle, and abutting against the wall of the 



