president's address — SECTION B. 81 



the vessel, a short distance above the bottom of the inner cavity. In 

 this manner a space was formed below the tuyeres, in which the metallic 

 copper had an opportunity of settling. Remaining quiescent, and out 

 of reach of the blast, it was not thrown against the lining, and did not 

 chill, but collected, and could be poured out in a body with the scoria 

 at the end of the blow. In addition to this very important mechanical 

 success, an equal feeling of triumph followed on the observation that 

 the metal thus produced was of a purity considerably exceeding that 

 of the ordinary black copper locally obtained by the usual roasting 

 and fining process, for it only contained 1 .5 per cent, of other elements. 

 The excessive quantity of slags formed during the blowing, however, 

 continued to constitute a scarcely less formidable difficulty than the 

 correct position of the tuyeres, and so remained, in fact, for a very 

 much longer time. Simple as the manipulation for the removal of 

 the slags really is, no matter what the original grade of the matte 

 treated, the solution was not actually found until some six years later — 

 after the process had been introduced in America. It happened that 

 in these earlv endeavors in France the method was assessed too ex- 

 clusively along the lines of the features of the iron-converting process : 

 such as a single blowing period and but a moderate production of slag, 

 and had not yet found an individuality of its own in the minds of the 

 experimenters. The abundant slag formation, the wear of the lining, 

 and other points nowadays accepted as matters of course, were greatly 

 lamented, and effort was wasted in their attempted suppression, instead 

 of working out the best mechanical procedure for their amelioration. 

 Mattes of 50 per cent, to 60 per cent, copper, it was found, offered little 

 difficulty, and could be finished to copper in one blow. A small addition 

 of quartz prevented the thickening of the modicum of slag such mattes 

 made, but spiegeleisen was found to be more serviceable by yielding 

 a fluid silicate of manganese, and keeping up the heat. The treat- 

 ment of 20 per cent, to 30 per cent, mattes up to the same end, however, 

 gave much trouble. This difficulty is now generally circumvented, 

 simply by not blowing such low-grade mattes. The early men, inno- 

 cently, expected the converters to serve all grades equally well, and 

 the method was, as a whole, so economical, compared with the ordinary 

 treatment, that fine shades of saving in handling and treatment were 

 not valued. Instead of bringing these low-grade mattes up to a proper 

 tenor in the preceding smeltiiig, they were blown to about 60 per cent, 

 in the vessel, poured out with the slag, allowed to cool, separated, re- 

 melted, recharged into a fresh vessel, and blown again, and this un- 

 necessary complication, as remarked, remained the practice for a 

 number of years. 



The original trials were made at the works of M. Manhes, at Vedenes, 

 and occupied a year. Then the process was currently introduced on a 

 working scale at Eguilles, in the vicinity of Sorgues (Dep. Vaucluse), 

 at an old plant provided with water power --an accidental mechanical 

 feature which, for a considerable period, was publicly held to be the 

 particular factor which rendered the ncAv process more economical 

 than the roundabout methods whose place it was usurping. The 

 F 



