SCHUYLKILL PERMANENT BRIDGE. > 29 



plished by them, without any assistance from the pub- 

 lic funds ; and where the want of scientific and practical 

 knowledge, was supplied by the constancy and singular 

 attention of those, who possessed no more talents or 

 acquirements, than are called for in the common affairs 

 of life. Such successful examples are worthy of imita- 

 tion ; and will incite to perseverance, in laudable and 

 necessary enterprizes ; however apparently difficult and 

 untoward ; as many parts of this work have most un- 

 doubtedly been. Nor is it desired to recommend pro- 

 ceeding (where it can be avoided) in such hazardous 

 undertakings, without professional engineers, both sci- 

 entific and practical. 



Few would have persevered under all the difficulties 

 attending this work; which in its execution (unavoida- 

 bly protracted by the embarrassments attendant on 

 building under water) occupied six years after the la^v 

 was obtained. Hovvever humble the merit of those 

 who engage in such undertakings may be considered, 

 they are far greater contributors to the happiness and 

 convenience of mankind, than those who, with victories 

 and triumphs, dazzle while they desolate, and ruin and 

 oppress the human race. 



DESCRIPTION OF THE BRIDGE. 



The masonry is executed on a plan suggested to the 

 mason, uncommon, if not new. The walls of the abut- 

 ments and wings, are perpendicular, without buttresses .^ 

 and supported by interior offsets. These are found com- 

 pletely competent to support the pressure of the filling 

 (which gravitates in perpendicular lines) without bat- 

 tering or contreforts. The abutments are 18 feet thick. 



