. Railway mechanical engineer . heat chamber. The passage ofthe current is as follows: Starting at the right hand side, thecurrent from a transformer is connected to the clamp H; itthen passes through the electrode F to plate E, to carbon pileD. to top plate B^ and over and down to the left hand clampH in a. similar manner, and to transformer. By varving the pressure applied to the adjusting screwsGG the resistance to the passage of the electric currentthrough the carbon plates D may be varied, which inturn overns the amount of heat transmitted to the heatingchamber. The furnace takes its curr


. Railway mechanical engineer . heat chamber. The passage ofthe current is as follows: Starting at the right hand side, thecurrent from a transformer is connected to the clamp H; itthen passes through the electrode F to plate E, to carbon pileD. to top plate B^ and over and down to the left hand clampH in a. similar manner, and to transformer. By varving the pressure applied to the adjusting screwsGG the resistance to the passage of the electric currentthrough the carbon plates D may be varied, which inturn overns the amount of heat transmitted to the heatingchamber. The furnace takes its current from a specialtransformer wound for low voltage and high current. This,however, mav he connected to the regular alternating currentshop lighting or power circuits. It can not be used on directcurrentcircuits. When starting, the current is switched onand pressure on the screws GG adjusted to obtain the correctflow of current. When the proper heat is once obtained vervlittle adjusting isrequired to maintain a uniform heat. A. Fig. 4 . Electric Bath Furnace proportions of each are given in instructions furnished bymakers of the furnace. These salts when cold are non-conductors of electricity, butwhen hot, readily conduct the current. In starting, it is cus-tomar>- to connect a piece of electric arc lamp carl^on to oneof the electrodes by a wire and strike an arc in the salt nearto the opposite electrode. As the salts melt, the carbon drawn away from the electrode. This forms acanal of melted salt, which conducts the current. With thecurrent once started across, the entire mass soon becomesliquid. It is customary to keep the furnace hot at all times,which is accomplished by allowing a small amount of currentto flow during the night or when not in service. Theelectrodes BB are made from pure wrought iron and areled in over the top of the crucible and down into the saltbath. These are connected to the secondary of a .special l^ 42 RAILWAY MECHANICAL ENGINEER Vol. 9


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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering