INDUSTKIAL PROGRESS DURING THE YEAR 1874. clxxv 



which these conditions shall be realized is an important feat- 

 ure of Mr. Blair's invention. He obviates the difficulty, be- 

 fore named, by increasing the height of the furnace, and 

 placing the zone of reduction so high up that, by the time 

 the iron sponge has reached the bottom in its natural descent 

 by gravity, it is already sufficiently cold to prevent oxida- 

 tion. To impart and maintain the necessary temperature, 

 it was found necessary to heat the ore in thin strata. This 

 was accomplished by constructing the furnace in the form 

 of a cylinder three feet in diameter, in the top of which was 

 suspended an inner cylinder, twenty-eight inches in diameter, 

 and about six feet long. The material is charged only in 

 the annulus, heat being applied both inside and outside. The 

 word " puddling," of course, finds no place in this process. 

 The experiments thus far made with it seem to have been 

 confined to rich ores from Iron Mountain and Lake Superior, 

 and the product requires no subsequent purification. The 

 assertion is made, likewise, that "titanium gives no trouble 

 in the direct process," which, if sustained by experience, will 

 greatly add to the value of the invention, since many rich 

 beds of titaniferous ore must remain unworked in ordinary 

 blast-furnace practice that can thus be utilized. Where 

 the ores used are impure, the product will require purifica- 

 tion, and this the inventor claims to be able to accomplish 

 in a gas-furnace of peculiar construction. The economy of 

 the process, which is after all the test of its value, is claimed 

 to be considerable. The process is being operated on a 

 large scale at Pittsburgh, though with what result we are 

 unable to state. 



The last year has witnessed also the invention and ex- 

 perimental trial of another direct process, which, although 

 details are meagre, seems to have excited an unusual amount 

 of attention. In reference to this novelty, Iron uses the fol- 

 lowing suggestive words : " It may have been thought by 

 some that with the Bessemer-steel process we had seen the 

 last startling innovation in the commercial manufacture of 

 steel; but, according to the latest news from Vienne, we are, 

 perhaps, on the threshold of another startling revolution." 



The invention which has called forth the foregoing com- 

 ments is a process which claims to effect nothing less than 

 the "direct" production of steel from the ore a problem 



