228 



ELECTROLYSIS. 



1200 square metres of anodes, including the parts which are 

 outside the baths. The thickness of the anodes is 10 milli- 

 metres, that of the cathodes 1 millimetre. The total weight of 

 the copper under treatment is 125 tons. 



COST OF FIEST ESTABLISHMENT. 



The market price of raw copper varies ; this may be pre- 

 judicial to manufacturers who slowly treat large quantities of it 

 at a time in the case of a persistent decline in the price. As 

 we are only comparing here a few systems of installation, we 

 may, to fix the ideas, assume that the price is 1600 francs (64?.) 

 per ton (this is the average price for the last two years). 



The value of the copper under treatment, in one of the in- 

 stallations of the Norddeutsche Affinerie at Hamburg, there- 

 fore represents the enormous sum of 200,000 francs (8000Z.). 

 Assuming an annual production of 330 tons, we see that for each 

 ton refined there must constantly be a value of 606 francs 

 (2,42. 5s.) of copper in the bath. 



At Marseilles 55 tons of copper are immobilised, which re- 

 presents a capital of 73,000 francs (2920Z.) for an annual pro- 

 duction of 80 tons or 910 francs per ton of refined copper. 



At Birmingham there is only 9840 kilogrammes (about 10 

 tons) of copper under treatment, of the value of 15,744 francs 

 (6307.), for an annual production of 104 tons, which reduces this 

 part of the absorbed capital to 151 francs per ton of copper refined. 



The ground space occupied is also an item in the expenses 

 of establishment, an item which very much varies according to 



