158 DISPLAY OF CHARACTER. 



and brought forward experiments which seemed to confirm 

 the effect. This induced Joule to make experiments to 

 disprove at once that pretence, " set up," he says, " to excuse 

 certain Railway Companies" for not having taken extra 

 precautions on account of the extra hardness of the 

 ground, " which is the common-sense explanation of the 

 accidents," but which pretence "although put forth in defiance 

 cf all we know of the properties of materials, but also of 

 the experience of everyday life, has yet obtained the 

 ■credence of many people." His experiments on darning 

 needles showed that at 1 2° Fahr. the needles were one per cent 

 stronger than at 55° Fahr., and that under the same circum- 

 stances the proportion of garden nails at 2 Fahr. which broke 

 was less than the proportion which broke at 40 Fahr. Joule's 

 only motive in taking needles and garden nails, arose 

 from the fact that for his experiment it was necessary to have 

 a considerable number of similar specimens of steel and 

 cast iron, sufficiently small to admit of ready experiments, 

 and the needles and garden nails came readiest to his hand. 

 At the time, however, the idea that engineers would pay 

 attention to experiments on anything so small as darning 

 needles and garden nails, was received with derision by 

 some of those present, and the discussion extended 

 over two more meetings. This gave those present 

 opportunities of seeing Joule under circumstances such 

 as had not happened within the memory of many, if of any, 

 of the members. He was much excited by the opposition, 

 and entered warmly into the discussion, hitting out straight 

 and with spirit, but at the same time with a dignity, courtesy 

 and kindness, which took the sting out of the hard things 

 hie said, and was very gratifying to witness. 



For Joule's communication on " Examples of the Per- 



