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MINUTES OF PKOCEEDINGS OF 
Lave been instituted reveal the somewhat startling fact, that frequently the 
inferior kinds of iron actually yield a higher result than the superior. The 
reason of this difference was shown to be due to the fact, that whilst the one 
quality retained its original area, only very slightly decreased by the strain, 
the other was reduced to less than one-half. Now, surely this variation, 
hitherto unaccountably completely overlooked, is of importance as indicating 
the relative hardness or softness of the material, and thus, it is submitted, 
forms an essential element in considering the safe load which can be practically 
applied in various structures. It must be borne in mind that although 
the softness of the material has the effect of lessening the amount of the 
breaking strain, it has the very opposite effect as regards the working 
strain. This holds good for two reasons: first, the softer the iron the less 
liable it is to snap; and second, fine or soft iron, being more uniform in 
quality, can be more depended upon in practice. Hence the load which this 
description of iron can suspend with safety may approach much more nearly 
the limit of its breaking strain than can be attempted with the harder or 
coarser sorts, where a greater margin must necessarily be left. 
“ Special attention is now solicited to the practical use that may be made 
of the new mode of comparison introduced by the writer, viz : the breaking 
strain per square inch of the fractured area of the specimen } instead of the 
breaking strain per square inch of the original area” 
