430 THE SCIENTIFIC PAPERS OF 



certain that, in the case of mild steel, to get rid of the honey- 

 combs they would have to resort to a pressure of 1 ton, if not of 

 2 tons, per square inch. 



With regard to the interesting question raised by Mr. Richards, 

 as to how the pressure acted upon the gases which had been 

 occluded, he confessed that he was in the same difficulty as the 

 President. He could not conceive how, by applying pressure to a 

 fluid mass, they could induce one ingredient out of several to go 

 from the centre to the outside, or from the outside to the centre. 

 The pressure was the same throughout over the whole surface ; 

 and all he could conceive was that by that pressure the volume of 

 say one cubic inch of gas would be reduced, if the pressure were 

 high enough, to say one-tenth of a cubic inch ; or it might be 

 that the gases would be reabsorbed in consequence of the pressure, 

 and thus return to their former combination with the steel. Mr. 

 Richards had drawn a comparison between steel and soda-water. 

 Now when the cork of the soda-water bottle was lifted, the whole 

 contents became a froth, and might be called spongy soda-water. 

 If the cork were pressed down again, the frothing would immedi- 

 ately cease, the gases being again absorbed in the liquid. There- 

 fore it Avas quite conceivable that by the application of a sufficient 

 pressure to fluid steel, although the gases were not expelled, they 

 might remain occluded in the steel. He imagined that this would 

 be the real solution of the problem. But there could be no doubt 

 that, if the cavities could be prevented in the ingots, a great gain 

 would be secured ; and he should be glad to see that, by the appli- 

 cation of so moderate a pressure as was mentioned in the paper, 

 this result could be obtained. 



While discussing the question of steel, he should be glad, with 

 the permission of the President, to make a few observations upon 

 the more general question of mild steel. Within the last week or 

 two a great deal had been said about this steel not being reliable, 

 and they had heard of boilers giving way mysteriously under a 

 very moderate pressure. It so happened that he had been made 

 cognisant of some of the circumstances regarding the failures 

 which had been prominently alluded to ; and he might say that, 

 although the first boiler had failed under pressure, the second was 

 found to be rent in precisely the same manner without any 

 pressure having been applied : clearly showing that it was not a 



