REFINING OF COPPER AND LEAD. 



229 



countries, but may be estimated at a minimum of 100 francs 

 per square metre on account of the buildings which have to be 

 erected on these spaces. 



The installation of the 120 baths at Hamburg, the passages 

 for the service, the engine and electric machine rooms, &c., 

 occupy a space of 660 square metres, which calculated upon 

 the basis of 100 francs per square metre, corresponds to an ex- 

 penditure of 66,000 francs for 330 tons per year, or to 200 francs 

 per ton. 



At Marseilles, with 40 baths, we must admit a space of 300 

 square metres for the whole of the services. That surface can 

 be valued at 30,000 francs for an annual production of 80 tons, 

 or at 375 francs per ton. 



At Birmingham, 160 square metres may be sufficient for a 

 production of 104 tons, which corresponds to a total expense of 

 16,000 francs, or to 154 francs per ton of copper. 



By adding together these various expenses, we obtain the 

 total outlay per ton of refined copper per year. 



COST PRICE OF THE KEFINING OF COPPER. The expendi- 

 tures incurred in the electrolytic treatment of copper are as 

 follows : 



1st. The interest of the engaged capital. 



2nd. The fuel and accessories required for the motor. 



3rd. The labour. 



4th. The maintenance and redemption of the material. 



5th. The general expenditure. 



A rate of 5 per 100 on the engaged capital can be admitted, 

 although the refining works generally belong to dealers in 

 metal, who have almost always a large stock of copper to guard 

 against the fluctuations of the market, and it is consequently, if 

 not absolutely immaterial to them at least not onerous 

 whether this copper is in the baths or in stock. However, in the 



