the Foundations of Bridges, &c. 4! 3 



the exertions of individuals in the employment of capital 

 turned from its proper courf^e, or to stem the torrent of 

 improvident speculations by conspicuous objects of abor- 

 tion. ' 



London i< not yet sufficiently wealthy for any projector, 

 however venturous, seriously to propose the method of 

 turning: the course of the river Thames, in order to lay the 

 founJation of a bridge. However great may be the com- 

 merce of the country, it has not been as profitable as the 

 conquests of a Trajan : but the time may come, after 

 having had recourse to the cofferdam, when his example of 

 turning the Danube may be imitated in respect to the 

 Thames. The eutperor Claudius, alihough he was an idiot, 

 seems to have been' a very able architect : he erecttd per- 

 haps the niost maenificent temple, namely the Temple of 

 P>.ace, left by the Romans: certainly there are in that struc- 

 tuie the ntnst scientific examples of vaulting remaining of 

 ancient architecture. FJe also invented, or approved the 

 invention by which the foundation of the port of Ostia was 

 laid : whether he understood the art of making; stone walls 

 swim, remains in doubt. The invention of caissons or 

 wooden boxes belongs to an age when both iron and stone 

 had been triade to float, and when that knowledjre would 

 seem to point out that caissons are altogether useless : at 

 least the emperor Claudius would have discovered, after he 

 had made stone piers s\yi,m bv means of ropes, that there 

 would not be any occasion fur boxes of wood, when the 

 pier itself bv having some vacuiiies in it could be made to 

 answer the same purpose. 



It is due to those whose public virtue leads them to 

 idorn the metropolis, and add to the advantages which 

 so eminently belong to it, that their labours, disinierestcd 

 as those labours must be where there has not been any ra- 

 tional hope of profit, should be attended with as little ex- 

 pense as possible: with that view the attention v)f \ our 

 readers has been called to the different modes by which the 

 foundations of the piers of bridi;es have been laid ; that they 

 may determine, according to the abilities which they may 

 employ, whether they siiould adopt the expensive methods 

 by turning the water into a new course, or by cofferdams, — ■' 

 methods of certain success under the management of or- 

 dinary abilities, — or whether they shall adopt the cheap 

 methods of the emperor Claudius or Si. Benezet, which re- 

 quire somewhat more talent and judgcmciit. 



Pd3 LXI. Further 



