PROGRESS IN ELECTRO-METALLURGY—KERSHAW. WALT 
lapsed in Europe in 1902, and the manufacture of aluminium by the 
electrolytic method can therefore now be carried on without the pay- 
ment of patent royalties. The use of the electric current for keeping 
the bath in the molten state is, however, still covered in America by 
the Bradley electric-furnace patents, which do not expire until 1909. 
In that country the Pittsburg Reduction Company therefore still 
possess the monopoly of the electrolytic reduction process. 
As regards utilization, the demand for the metal in Europe during 
1906 has been in excess of the output, and the reduction plants are 
being extended in several of the works, in order to benefit by the 
higher prices now obtainable for the metal. The British Aluminium 
Company, in addition to the development of a new water power in 
Switzerland, are carrying out a very large scheme on Loch Leven in 
Scotland, which when completed will add enormously to their power 
resources in Scotland. The Aluminium Industrie Aktien Gesell- 
schaft, of Neuhausen, are likewise developing a large power scheme 
on the River Navisonce in Switzerland, from which it is expected 
that: 25,000 horsepower will be derived. A new aluminium works 
has been erected by an Italian company in the Valley of Pescara in 
Northern Italy, and is about to commence operations. In a few 
years, therefore, the productive capacities of the aluminium com- 
panies will be more than doubled, and it will be of interest to note 
whether the demand shows a similar expansion. 
The metal is now being used in very large quantities for motor- 
car construction and for general foundry work, while the “ Thermit ” 
and ‘* Weldite ” processes also consume large quantities of aluminium 
in the form of powder. In every direction in which the metal has 
been applied with success its use has increased during 1906. 
Mr. Schoop, of Paris, has worked out the details of a process for 
the autogenous welding of aluminium which overcomes the diffi- 
culty of finding a suitable solder for the metal. By this process 
aluminium sheets, rods, or tubes, of any thickness, can be welded 
without any difficulty, and the joints are said to be as strong as the 
other parts of the metal. This method of welding will probably 
lead up to increased consumption of the metal in many industries and 
to its use for larger articles and vessels than have yet been manu- 
factured from it. Another direction in which the use of aluminium 
is extending is for the manufacture of pans, etc., for use in the wax- 
refining and jam-boiling industries, which have hitherto employed 
copper vessels for this purpose. 
Bullion refining—FElectrolytic methods have been applied with 
great success on both sides of the Atlantic in the refining of gold and 
silver bullion, the Moebius process being used for silver and the Wohl- 
will process for gold.. In the Moebius process a dilute solution of 
silver nitrate containing free nitric acid is employed as electrolyte, 
