14 Design for a Bridge [Jan. 



Article IV. 



Design for a Bridge across the Mersey, at Runcorn. By 



J. C. Loudon. 



(With a Plate.) 

 SIR, 

 I send you herewith some sketches, with explanatory re- 

 marks, of a design for a suspended bridge, which I had pre- 

 pared for the committee at Runcorn (see Phil. Mag. for May 

 last) ; but from some untoward circumstance, the choice was 

 made before I learned that it was time to give in the plans. I 

 had constructed a model for a similar design; which I mention 

 here, merely to record that I have sent it to a friend in Poland, to 

 be presented to the Royal Society of Warsaw. It was in that city, 

 in the spring of 1813, that the idea of a suspended bridge first 

 occurred to me, as suitable for crossing the Vistula, there nearly 

 2000 feet wide. Having passed the following winter in Peters- 

 burgh, the magnificent ramifications of the Newa, the want of 

 a permanent communication between the two principal parts of 

 the city (sometimes unconnected for two or three weeks together 

 by the floating ice), and the inspection of numerous designs 

 and models for bridges adapted to these circumstances, induced 

 me to pursue the subject still farther. After my return to England, 

 in July, 1816, I made some sketches; and having shown one 

 of these to Mr. Telford, that gentleman obligingly showed me 

 his design for Runcorn (since engraved), which I concluded 

 was approved of, and therefore paid no attention to the subject, 

 till in May last I saw an advertisement inviting artists to give in 

 designs, &c. I have no other object in wishing to publish my 

 design than that of inducing scientific men to direct their atten- 

 tion to a subject which is of considerable importance, not only 

 to this country, but to every other. 



I am, Sir, your most obedient servant, 



Baystcater House, Aug. 10, 1817. J- C. LoUDON. 



Data. 



As the merits of every design must necessarily have a reference 

 to the object in view, the author of that now submitted begs 

 leave to premise the data and information on which he has pro- 

 ceeded in its arrangement. It is considered as desirable to- 

 establish a communication between the counties of Lancaster 

 and Chester, by a bridge across the Mersey, at Runcorn Gap, 

 about eight miles from Warrington ; and it is a sine qua non that 

 the navigation of the Mersey, which is considerable, be uninter- 



