872 Agricultural Gazette of N.S.JF. [Nov. 2, 1908. 



Cominencing witli a imxlrst experimental jilaiit (if oiilv -■") liorse-power, 

 operations expanded i-apidly, until a factory was Imilt at Notodden, in the 

 Hittersdal, with a horse-power of '2. IOC. supplied by the Tinnfos ^^'aterfall. 

 Shortly after this came into operation it became necessary to incic^ase the 

 output tenfold in older to meet the demand for nitrates, and another water- 

 fall, capable of l^G, ()()() horse-power, was ci^lled into requisition. Other 

 similar projects are now in coui-seof deNclopmciA in Scandinavia, and a large 

 water-power factoiy is also bciny' erected in Italy. 



Interior of the Birkeland-Eyde Furnace. Showing the striking of the electric flame. 



The generating power at Notodden and Svaelgfos is produced at a cost of 

 about 0'02") of Id , which is rather less than Sir William Crooke's estimate 

 of 1-17 of Id. The ([uality of the lutrate of lime is quite eijual to that of 

 Chilian saltpetre : and the Norwegian product can be mainifactured at a 

 cost of not more than one-half the price at which the Chilian ai-ticle can l)e 

 delivered at Hamburg or Christiana. 



2. Manufacture of Calcium Cyanamide. 



The Birkeland-Eyde calcium-nitrate process has not been allowed to re- 

 main in undisputed possession of the field. Another method of h.xing jntrogen 

 is the formation of a substance calletl cyanamide by the electric heating 

 of calcium carbide in a stream of atmospheric nitrogen. Calcium cyanamide 

 is manufactured from the same quality of carbide as is used in making 

 acetylene gas. Pulveiised caibidc is charged into retorts mounted in a 

 furnace, and nitrogen is jiassed ovei' the carbide. When the carbide is 

 saturated with nitrogen the cyanamide is extracted in the form of a hard 

 ■cake. After being cooled this substance is pulverised, and is then ready for 

 use. It is placed on the market untler the name of Nitrolim. Souietimes it 

 is called "Lime INitrogeii." 



While its jn'incipal use is as a fertiliser to take the place of Chilian 

 saltpetre, cyanamide is also usetl for making (pnte a variety of chemical 

 products. 



