Page:Popular Science Monthly Volume 40.djvu/33

Rh tall cast-iron standards, and was turned by worm-gearing arranged to be driven either by band or power. The engine which supplied the blast to the converter is represented in front elevation by Fig. 63; it was constructed from original working drawings made by the writer. It was intended to produce a pressure of blast of sixteen pounds per square inch, which was regarded as very heavy; in fact, I was informed, at the time of commencing the plans for this engine (the winter of 1862-'63), that the pressure used for blowing steel in England and Sweden was but eight pounds. I adopted the higher pressure with a view to shortening the time required for a "blow," but I soon became satisfied that this was a mistaken departure. I found myself in most excellent company, however, for, before my engine was finished, steel was blown in England with a blast pressure of twenty-five pounds, a practice which has continued until the present time. The engine had three upright cylinders of the same internal dimensions (twenty-four inches in diameter and thirty-six-inch stroke), the middle one being the steam cylinder and the outside ones the blowing cylinders.

Very soon after entering upon the study of the new process it became evident to me that an accurate knowledge of the chemical constituents of the metals and other materials employed was essential to its successful conduct; for, after we had found by working them that certain irons were, and others were not, suited to our purpose, analysis would in future enable us to determine whether any offered brand of iron was of suitable quality. These considerations, with others, determined the addition of a chemical laboratory to the works.

As late as 1868 a large establishment for the manufacture of steel (in which over a million dollars was invested) commenced operations in western Pennsylvania, and at the end of one year it was abandoned and dismantled, the whole of the investment having been utterly lost in consequence of attempting to use material which an analysis costing not over fifty dollars would have shown to be absolutely unfit for the purpose intended. American "iron-masters" (so called) were not alone in their contempt for chemistry. I have in my possession a pamphlet published by a well-known firm of steel manufacturers in Sheffield, England, as late as 1870, for the purpose of attracting attention and trade, in which the following sentences occur: "The various articles on the