SCHUYLKILL PERMANENT BRIDGE. 33 



A number of Conductors, properly disposed, secure 

 the superstructure from danger by lightning. 



All that could be spared for ornament, was expended 

 on the exterior; as the interior neither admitted nor re- 

 quired it. The Pediments of the entrances were intend- 

 ed to be finished with Emblems of Commerce^ on the 

 east; and of Agriculture^ on the v\^est. They are design- 

 ed, and were to be executed, by that eminent American 

 naval sculptor, TFilliam Rush of Philadelphia; whose 

 works as an artist, are admired, in whatever part of the 

 world they are seen. It is desirable ihaXi\\\s Jinishy the 

 expence whereof will be small, should yet be added. 

 The Pediments require it ; to complete the design. 



GENERAL OBSERVATIONS. 



The Schuylkill Bridge Plan may be varied according 

 to circumstances ; and its principles preserved. In what- 

 ever varieties, projectors of other designs may indulge 

 themselves, it is confidently believed that Mr. Palmefs 

 plan will be found on long experience, to be the best. 

 It is an unit in symmetry and movement; and all its 

 parts support each other, like 2i phalanx in tacticks. In 

 some instances Mr. Palmer has placed the platform for 

 travelling, over the cap pieces and cross ties ; or rather 

 these latter become part of the frame of the platform. 

 The great body of the frame is of course below. But 

 this was not found eligible, where ice and floods were 

 likely to assault the haunches, when the frame was thus 

 depressed. The elevation of the abutments would re- 

 quire, for this plan, immense weight and expence of fill- 

 ing, and expose the walls to dangerous pressure. Nor 



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