528 



METALLURGY. 



tant changes the bill was passed by a decisive 

 majority. The vote in favor of striking out 

 the drawback, free ships, and free materials 

 provisions, was 159 to 54. 



The bill went to the Senate and was re- 

 ferred to the Committee on Commerce. Strong 

 objection was made by the regular lines of for- 

 eign steamers to the fifteenth section, which 

 would increase their tonnage dues materially. 

 Under existing laws these dues were thirty 

 cents a ton per year. This bill would make 

 them twelve cents a ton for each entry, and 

 some of the regular steamers made ten or 

 twelve entries in a year. On the other hand, 

 many foreign sailing-vessels did not enter an 

 American port more than once in a year, and 

 their tonnage dues would be materially re- 

 duced. The Senate committee agreed to 

 strike out this whole section, and also the 

 thirteenth, which dispensed with the necessity 

 of employing seamen through the intervention 

 of the shipping commissioner. The committee 

 then added a section repealing the provisions 

 of the existing statutes which obliged all 

 American vessels to carry the mails at a rate 

 of compensation not exceeding the ocean post- 

 age, and providing for contracts with vessels 

 of American registry for carrying the mails, 

 under which the Government should pay "not 

 exceeding one dollar per mile on the trip each 

 way," contracts to be entered into, after pub- 

 lic advertisement, with the lowest responsible 

 bidder. The aggregate to be expended for this 

 service was limited to $1,500,000 per year, and 

 the term of the contracts was to be for four 

 years. The bill as amended was reported to 

 the Senate, but not taken up for action until 

 the last day of the session. The amendments 

 striking out the thirteenth and fifteenth sec- 

 tions were then agreed to, and that providing 

 for a mail subsidy was rejected, and the bill 

 was then passed and sent to the House for 

 concurrence in the amendments. That body 

 was engaged in contest over an election case, 

 in which the Democrats were filibustering to 

 prevent action, while the Republicans would 

 permit nothing else to be dona. The result 

 was, that no further action could be secured 

 on this important measure, and it failed, leav- 

 ing American shipping without any relief 

 whatever from the burdens and exactions 

 that have so nearly destroyed it. 



METALLURGY. IRON - SMELTING BY THE 

 DIEEOT PKOOESS. The Siemens direct process 

 for smelting iron has come into general use, 

 with satisfactory results in effecting a saving 

 of time and in the consumption of fuel, the 

 principle of which was stated by Dr. Siemens 

 in a communication to the Iron and Steel In- 

 stitute in September, 1877, as follows: "In 

 mixing comparatively rich iron-ore in powder 

 with about 25 per cent of its weight in pound- 

 ed coal, and in exposing the mixture for some 

 hours to the heat of a common stove or of a 

 smith's fire, metallic iron is formed, which, on 

 being heated to the welding-point on the same 



smith's hearth, may be forged into a horse- 

 shoe of excellent quality. The admixture with 

 the ore of some fluxing material, such as lime 

 or clay, will, in most cases, be of advantage to 

 rid the iron of adherent slag. The process is 

 conducted in a rotatory furnace, as follows: 

 The ore to be smelted is broken up into frag- 

 ments not exceeding the size of peas or- beans; 

 to it is added lime or other fluxing material, 

 in such a proportion that the gangue contained 

 in the ore and flux combines, with only a little 

 protoxide of iron, into basic and fluid slag. 

 A charge of, say, 20 cwt. of ore is put into the 

 furnace when fully heated, while it is slowly 

 revolving. In about forty minutes this charge 

 of ore and fluxing material will have been 

 heated to bright redness, and at the same time 

 from five to six cwt. of coal of uniform size are 

 added to the charge, while the rotative velocity 

 is increased, in order to accelerate the mixture 

 of coal and ore. A rapid reaction is the re- 

 sult: the peroxide of iron, being reduced to 

 magnetic oxide, begins to fuse, while metallic 

 iron is precipitated by each piece of carbon, 

 and the fluxing materials form a fluid slag with 

 the silicious gangue of the ore. Resorting 

 again to the slow rotative action, the mass is 

 turned over and over, presenting continually 

 new surfaces to the heating lining and to the 

 flame within the rotator. During the time 

 of this reaction, carbonic oxide, besides the 

 hydrocarbon contained in the coal, is evolved 

 from the mixture of ore and carbon, and heat- 

 ed air only is introduced from the regenerator 

 to effect its combination within the rotating 

 chamber. When the reduction of the ore is 

 nearly completed, the rotator is stopped in the 

 proper position for tapping off the fluid cinder, 

 after which the quick speed is imparted to it, 

 by means of which the loose masses of iron 

 contained in it are rapidly collected into two 

 or three metallic balls. These are taken out 

 and shingled in the usual way of consolidating 

 puddled balls, when the furnace is tapped 

 again and is ready for another charge at once." 

 Comparing, on theoretical grounds, this meth- 

 od of producing iron with the operation of the 

 furnace, it appears that while in the blast-fur- 

 nace the products of combustion consist chiefly 

 of carbonic oxide, and issue at a temperature 

 of more than 350 C., the result of combustion 

 in the rotatory furnace is carbonic acid, the 

 temperature of which rarely exceeds 175 C. 

 Dr. Siemens estimated that his process was 

 competent to produce a ton of iron balls with 

 a consumption of 25 cwt. of coal, and a ton of 

 cast steel with a consumption of 40 cwt. of 

 coal. The first effort to introduce the process 

 into the United States, which was made at 

 Pittsburg, Pa., in 1878, was pronounced a fail- 

 ure. Afterward a rotator was set up at Ty- 

 rone, Pa., on a plan a little larger than that 

 used by Dr. Siemens, from which between 80 

 and 85 per cent of the iron in the ore was pro- 

 duced, with 3,800 pounds of coal per ton of 

 blooms. The results were considered sufficient- 



