11 



follows, of course, that scrap iron now must be made from 

 our own scraps ; and when it is remembered how small a 

 proportion of good iron has for many years been made 

 here, bars, &c., manufactured from scraps, cannot but be of 

 very irregular and dubious quality ; hence it is that the best 

 scrap iron cuts so poor a figure when compar<ed with a well 

 made iron from known good minerals. 



The remarks I have made are in reference to irons of 

 known good quahty ; but I am ready, and have pleasure in 

 admitting that the use of hot air has been of very great 

 advantage at those iron works whose produce had not a first- 

 rate name, by enabling their proprietors to make it at a less 

 cost, without a proportionate deterioration in quality; and 

 there are some few works whose iron, made with cold blast, 

 was so bad, that any change could not be but for the better. 

 There is also at present a strong impression that iron cannot 

 be made with anthracite coal only, without hot air, and that 

 iron so made is better than any other. The goodness of its 

 quality is, however, due to the great purity of that coal. But 

 even here we are told, in a Paper read before the Polytechnic 

 Society of Cornwall, by a gentleman of great practical skill, 

 that iron made with such proportions of anthracite coal and 

 coke as enabled him to use cold blast, became much weaker 

 on his using hot air, all other circumstances being the same. 



My apology for troubling you so far must be in the import- 

 ance of the subject, and the daily increasing importance to 

 society of the strength of that material by which the loco- 

 motive power is applied that so rapidly conveys a very large 

 portion of the human race both by land and sea. When we 

 are about to purchase a horse which is to convey ourselves 

 and families at the moderate rate of eight or ten miles an 

 hour, with what inherent caution our first object is to examine 

 his knees, to ascertain his safety ! In the steam-engine we 

 are prevented taking this precaution ; and yet in travelling 



