FURNACE REACTIONS UNDER HIGH GASEOUS PRESSURES. 



423 



provided with various fittings for the introduction or circulation of gas, gauges for 

 measurement of pressure, windows for olxservation and, finally, with insulated carbon 

 holders leading the current to the inside of the furnace. Within this shell many 

 different forms of furnace, such as vertical or horizontal arc or resistance core, could 

 be built up as illustrated in fig. 1 1 (p. 438). 



The construction of the enclosure will be easily understood by reference to tigs. 1 

 and 2, giving sectional drawings. The shape of the interior is cylindrical, 10 inches 



Fig. 1. Sectional drawing of large pressure furnace. 



A. Main forging, 1 inches ruling thickness increased to 2 inches over central lelt, through 



which the various openings are bored. 

 C. Water jacket surrounding the body of the furnace. 

 H. Water jacket surmounting the cover. 



B. Cover held down by ten 2J-iuch studs, the joint being made by a lead ring placed in 



the spigot groove S. The projection N protects the joint from contact with the hot 

 gases when the furnace is in use and shields it from mechanical injury while the cover is 

 lii-ing lifted or replaced. 

 L. Cast-iron lining. 



diameter by 17 inches long, with hemispherical ends, one of which forms the cover B 

 and is held in place by ten 2^-inch studs (F,, F 2 ) which are fixed into a flange of the 

 main forging. The cover is rendered gas-tight by a spigot joint S, packed with lead ; 

 it is surmounted by a cast-iron casing H, through which cooling water was circulated. 



The main forging A is surrounded by the cast-iron water jacket C. 



Both the hemispherical ends of the furnace have projections K,, K a bored out to 

 a distance of 3 inches. 







The carbon holders which move in these recesses are thus protected from the direct 

 heat or flame of the furnace. The length of the projections KI, K, is sufficient to allow 



