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generally, a large number of individuals depending upon 

 them for their daily bread. Many eminent men, from Sir 

 Humphry Davy to the present time, had been endeavouring 

 to alleviate the amount of wretchedness which they were so 

 frequently, he was sorry to say, called upon to deplore, and 

 he felt glad that their worthy Secretary, Mr. Thorp, had 

 also entered the list for effecting so desirable an object. The 

 second Paper to which he alluded was " On the Strength of 

 Materials." Now, when he saw such stupendous under- 

 takings in connection with our various railways, the viaducts, 

 bridges, &c., it often occurred to him how essential it was 

 that the utmost caution should be used in their construction, 

 that they should be upon the soundest principles, and of the 

 materials most likely to resist the constant wear and tear to 

 which they would afterwards have to be subjected by the 

 passing and re-passing of the railway trains. He should 

 now call upon Mr. Ward to read the first Paper. 



ON THE STRENGTH OF MATERIALS. BY WILLIAM SYKES 

 WARD, ESQ., LEEDS. 



After briefly alluding to various formulae for the cal- 

 culation of the strength of beams, and particularly the 

 experiments and formulse of Mr. Hodgkinson, as published in 

 several of his Essays in the Philosophical Transactions, and 

 Reports of the British Association, and in a more accessible 

 form in the second part of his new edition of Tredgold's 

 Essay on the Strength of Cast Iron, and which were ex- 

 emplified by numerous diagrams, Mr. Ward observed, I 

 do not find that the strength of wood beams trussed with 

 rods of wrought iron has been investigated by any writer on 

 the Strength of Materials. I have given some considera- 

 tion to the obtaining a formula for finding the additional 

 strength which the rod of iron gives to the wood beam, 



