194 Mr. White's Design for the New London Bridge. 



If the plan and elevation show the dimensions of the con- 

 stituent parts, and the disposition of the several courses, they 

 will at once remove all doubts on this head. 



April 5, 1823. 



If the paper on the plans for erecting a nevi^ London Bridge, 

 distinguisiied by the signature " Amicus," and the letter ad- 

 dressed to the Comptroller of the Bridge House Estates, be 

 laid before the Committee of the House of Commons, they 

 will of course be accompanied by the requisite plans and ele- 

 vations. But besides these, I think it would be adviseable 

 to send with them a letter, addressed to the Chairman of the 

 Committee of the House of Commons, in which he should be 

 informed as briefly as possible, that these two papers were laid 

 before the Bridge House Committee, and that the author of 

 them offered to lay before that Committee a third communi- 

 cation, in which his ideas should be further developed ; but 

 that they refused to receive any further communication. That 

 you now, therefore, beg to solicit the attention of the Com- 

 mittee of the House of Commons to the same subject, hoping 

 that you will be able to convince them that a bridge upon the 

 cementitious principle, while it should possess all desirable 

 elegance, would be at least as durable as any other structure 

 that could be proposed, and would also be cheaper by about 

 a fourth of the whole sum, than an elegant, commodious and 

 durable bridge, erected upon any other plan. You should 

 also advert concisely to the advantages that would result from 

 the adoption of a proper system of lockage, as more fully ex- 

 plained in the second paper. And query, — should you not add 

 that you are ready to give the Committee personally any 

 further explanations they may require? 



Dr. Gregory also suggests, that it would be a very great 

 advantage if the road could be carried nearly on a level to a 

 point someway up Fish-street Hill, with an arch underneath, 

 allowing carts, &c. to pass from Thames-street, without ob- 

 structing the passengers over the bridge. 

 [To be continued,] 



XXV. On Electro- Magnets, ^y W. Sturgeon, Lecturer on 

 Experimental Philosophy at the Honourable East India Com- 

 pany s Militart/ Academy, Addiscombe.* 



VITHEN first I showed that the magnetic energies of a gal- 

 ^ ' vanic conducting wire ai-e more conspicuously exhibited 



* Communicated by the Author. 



by 



