RECOEDS OF MEETINGS. 751 



which had reacted with the carbon, sand was substituted for the clay 

 befoj-e used. Mr. Acheson then planned a furnace substantially the 

 same as that now used in the manufacture at Niagara, — a central core 

 of carbon pieces resting on the floor of the furnace and connecting 

 heavy carbon terminals or electrodes, around which core was packed 

 the mixed materials to be heated, which in the case of the production 

 of carborundum are sand, coke-powder, and a little common salt. 



"Meeting with troubles and trials, the usual lot of pioneers, and 

 having his efforts at last crowned with success, the carborundum 

 manufacture has become a large industry. In 1S94 a steam generat- 

 ing plant of less than loO horse power was used, and the cost of produc- 

 tion greatly restricted the applications of the product. Only one half 

 the product found a market. It was then that, in spite of the opposition 

 of the directors of his company, Mr. Acheson insisted on removing to 

 Niagara, so as to manufacture more cheaply with large amounts of 

 relatively cheap electric energy. The wisdom of this insistence soon 

 became manifest. One thousand horse power was consumed in a single 

 carborundum furnace. In 1904 the Carborundum Company had a plant 

 of five thousand electrical horse power, and produced over seven mil- 

 lions of pounds of carborundum or silicon carbide. 



"Later on Mr. Acheson found that when carborundum was very highly 

 heated in the furnace in which it was formed the silicon was evapo- 

 rated from the crystals and graphite left as a pseudomorph. This 

 observation led the way to experiments and methods which formed the 

 basis of another large industry carried on by the National Acheson 

 Graphite Company at Niagara. Its product is plumbago, a graphite 

 made by heating to a high temperature impure carbon, such as anthra- 

 cite coal. The silica and clay in the ash apparently provide material 

 for the chemical changes which result in the conversion, and the im- 

 purities are themselves finally vaporized out of the mass to a large 

 extent. That impure carbon was convertible into graphite at high 

 temperatures was known. Eods of carbon were so converted by the 

 writer in 1882. The carbon electrodes of arc lights, especially large 

 arcs, were noted to have been after burning so converted for a small 

 distance from the ends at the arc, and this was particularly noticeable 

 at the positive craters of large arcs, which, of course, during burning 

 attained a temperature limited only by the sublimation of the carbon 

 itself It is, however, due to Mr. Acheson that the production of arti- 

 ficial graphite has become a great commercial success. Rods, bars, plates 

 of carbon converted into Acheson graphite, are now extensively used 

 in electro-chemical and electro-metallurgical industries, almost to the 

 complete exclusion of the ordinary moulded carbon formerly used. 



