THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



MA Y 1892. 



XL VI. On the Resistances to Transverse Strain in Beams. 

 By Robekt Cradock Nichols *. 



A COMMUNICATION was made to the Royal Society in 

 1855 by Mr. W. H. Barlow, in which a new theory was 

 propounded to account for the amount of strength exhibited 

 by bars or beams of cast iron subjected to transverse strain, 

 which could not be reconciled according to any previously 

 suggested hypothesis with the results obtained from experi- 

 ments on direct tension. 



Shortly stated, Mr. Barlow's theory was this : that in 

 addition to the resistances to deflexion or rupture called into 

 action by the compression of the fibres on the one side, and 

 their extension on the other side of the bar, a further amount 

 of resistance was developed by the lateral action of the fibres 

 caused by the curvature of the bar, which he termed a resist- 

 ance to flexure. 



Mr. Barlow gave in his paper an account of a number of 

 elaborate experiments which he regarded as establishing the 

 truth of this theory, and further developed it in an algebraical 

 form in a series of equations which were made to correspond 

 with the experimental results. 



The theory thus proposed has since been generally accepted 

 and approved, and has continued to the present time to be 

 regarded by the best practical authorities as the true expla- 

 nation of the facts ; though a doubt has been expressed 



* Communicated by the Author. 

 Phil. Mag. S. 5. Vol. 33. No. 204. Mai/ 1892. 2 E 



