Hodgkinson on Suspension Bridges and Iron Beams. 20 7 



friendly feeling towards him; and although an entire stranger to us, 

 we wish him every success in his laudable endeavour to build up an 

 honourable reputation for himself: yet we earnestly counsel him not 

 again to attempt the destruction of that of his neighbour; as it be- 

 trays both bad taste and bad feeling, and may eventually convert into 

 personal enemies those who might otherwise become useful friends. 



On Suspension Bridges; containing an Inquiry into the proper Forms 



of their Catenaries ; with Remarks on the Menai Bridge, and that 



at Broughton ; as likewise some Account of the Failure of the latter, 



B?/ Eaton Hodgkinsox, Manchester, 1831. 



In the eastern parts of the worlds rope and chain bridges of large 

 span have for a long period been in use ; but in Europe the adoption 

 of bridges of suspension is of comparatively modern date, and has 

 opened a new and interesting field for inquiry and experiment, both 

 for the engineer and the mathematician, and has rendered of practical 

 importance the theory of the catenarian curve, During the last cen- 

 tury, mathematicians investigated many of the properties of this curve; 

 but the addition of the materials which are necessary to form the road- 

 way, and to insure sufficient strength for the variable and large loads 

 of transit, have added new data to the problem. 



Mr. Eaton Hodgkinson has, in the present treatise, given a very 

 clear abstract of the properties of this curve under all the probable 

 variations it is liable to in its application to bridges of suspension ; 

 not only when the substance of the chain is of uniform strength, but 

 also when the strength varies as the strain, — concluding with an ex- 

 ample upon assumed data. 



The neat and elegant manner observed throughout renders the 

 tract a desirable object in the library of the practical engineer. 



The second part of the work contains an account of the chain bridge 

 at Broughton, near Manchester, with a particular estimate of the 

 strain upon the various parts as compared with the strength, and 

 also some important information on the form of the joints of the 

 links ; to which are added some observations on high tests, and on 

 defective welding of the bars. 



Next follow a few remarks on the Menai Bridge, showing that it 

 posses.ses sufficient strength to support seven times its own weight. 



An Appendix is given, containing remarks and obseVvations on the 

 cause of failure of the bridge at Broughton, after standing some years, 

 but which has since been repaired and made more secure*. 



Theoretical and Experimental Researches to ascertain the Strength and 

 best Form of Iron Beams. By the same Author. 

 The builder and engineer will find in this treatise many important 

 experiments, conducted with great skill, and described with accuracy 

 of detail. It should be read by every person who intends to use iron 

 beams. The author has long been known for his abilities as a mathe- 

 matician, and his ap|)lication of those abilities to practical purposes. 



* An account of the fall of the Droiighton Suspension Bridge, with some 

 particulars of the causes of its failure, were given in Fhil. Mag. and Annals, 

 N.S. vol.ix. p.;J84. 



