iri;\.\(T. 



men <:ASK<>IS 



457 





TABLE VI. Details of One Typical Carborundum Experiment. 



Large furnace enclosure used in vertical position (Plate 6, fig. 1). 



Iron liner filled as shown in fig. 11, B. 



Central resistance core of granular retort carbon packed in thin-walled brass tube 30 centims. long, 

 i''ii ri-iiiiiiis. diameter. 



Electrical connection at top and bottom of core made by graphite discs 5 centims. thick and 8 centims. 

 diameter. 



Charge : mixture of 7J kilogs. white Calais sand and 4 J kilogs. finely ground retort carbon ; calcined 

 shortly before experiment. 



Iron pot lined with thin sheet of asbestos. 



Initial pressure atmospheric; gaseous products of reaction retained up to about 100 atmospheres, then 

 let off and pressure maintained constant. 



E.M.F. at the terminals of the generator varied as required, and usually 2 to 3 volts above that in the 

 furnace. 



VOL. CCVII. A. 



3 N 



