70 



ELECTROLYSIS. 



THERMO-ELECTRIC BATTERY. The Noe battery (Fig. 8) 

 is composed of German silver and an antimonious alloy. The 

 active solder is not directly heated ; it is inclosed in a brass 

 cap from the centre of which emerges a rod of red copper, one 

 end of which terminates in a point. The said point is heated 

 by the jet of a gas-burner. 



FIG. 8. 



Noe Thermo-Electric Battery. 



The cold soldering is made with tin. In order to facilitate 

 the cooling, a few thin sheets of brass of great surface are 

 soldered together ; the surrounding air maintains them at a low 

 temperature. This cell or element has an electromotive force 

 of about T V volt and an internal resistance of ^ ohm. 



A battery of 25 elements decomposes water. 



In Austria, the goldsmiths frequently use a Noe battery of 

 40 elements and heated by gas, for their operations of gilding, 

 silvering, and nickeling. Its capacity is not great, but the 

 apparatus is a simple one. In the various works where we 

 have seen it in operation, we have been told that its duration 

 was to a certain extent considerable. 



CLAMOND THERMO-ELECTRIC BATTERY. M. Clamond has 

 equally adopted the zinc-antiinony alloy recommended by 



