74, A STATISTICAL ACCOUNT OF THE 



plished on an extensive scale. Every projector of such 

 arches or inventions, has an exclusive confidence in his 

 own project; and some of them pronounce phihppics and 

 denunciations, against bridges on piers. The expence 

 and difficulties attending these, ai'c too well known, to 

 be disputed ; or to require display and enumeration. But 

 actual experience, from the most remote times to this 

 day, has warranted their being employed ; preferably 

 to untried, however ingenious schemes. The advanta- 

 ges of single arches, for navigable streams particularly, 

 are obvious \ and experiments, on any feasible plan, are 

 devoutly to be -wished. It is easier, in man)' cases to 

 vault over, than to encounter, difficulties and dangers. 

 But the question is, who can affi^rd it, or will take the 

 risque of the first leap, in an expensive operation. 

 Hitherto no very extensive single arch has been hazarded 

 in practice ; unless the one at Weremouth^ be considered 

 as a decided example. Yet, at the timiC of erecting the ^ 

 Schuylkillhri^^^^ there were great doubts of the stability 

 of the Weremouth arch, suggested by a respectable En- 

 glish Engineer, who went expressly to view it. Inso- 

 much that the inventor, and executor of that work, who 

 was conversed with, pointed out defects; and it appeared 

 had changed and improved his plans, in after erections. 

 It would have been unjustifiable, in those who had the 

 trust of other persons money, to put it at the risque on 

 a theory, however plausible. When engaged in a plan, 

 dictated by experience and former practice, they were 

 corapelled to hazard^ by necessity^ in the progress ; and 

 justified by success^ in the event. 



Those who v/ish to indulge their curiosity, and exer- 

 cise their patience on such subjects, may have the op- 

 portunity afforded, by the perusal of the voluminous 



