l66 METALLURGY OF CAST IRON.
grained iron would have given him too weak a result in his castings, on account of there being chances of its being too high in silicon; or again, by ignoring analysis and taking open iron wherever found, he might receive some so low in silicon as to make his casting white iron. The author has heard shippers say, " Well, if the fool does not know better than to order iron by fracture, let him suffer his losses.'' The author has known cars of nice open iron to have but .75 up to 1.25 in silicon go to founders wishing soft light castings, simply because they insisted that the iron be opened-grained and ignored analysis. Such iron could do nothing other than give hard iron in any castings less than 2 inches thick. But as long as this founder had his open-grained iron he could turn to changes in the fuel, scrap irons, blast, weather, methods of charging, etc., to make excuses for his ill results, and not until such a paper as this, exposing the true cause of his trouble, might by chance fall into his hands is there any hope of his being made a follower of the new-school practice.
The second illustration of where self-interest has retarded the advance of chemical analysis lies in advocating the use of testing machines, as affording the founder sufficient means to regulate his mixtures without resorting to chemical analysis. Testing machines have their place, and most founders should possess one, but the practice of taking advantage of the prejudice, etc., of the old-school methods to antagonize the advance and true utility of chemical analysis in the self-interest of a more rapid sale of testing machines, is to be deplored.
The foundation of the old-school method in regulat-alysis, the chances are that his open-arding the advance of the new, see page 179.n is simply an average of the whole, generally taken from the two ends andith the uncertainty of furnace workings when in urgent need of ten hundred jon of iron; and Sir........................ 2,720 "