15 rnErort—1890. 
would probably receive advartageous application for the attainment of 
temperatures exceeding the limits (about 1800° C.) beyond which 
combustion was known to proceed very sluggishly. This prediction 
appears to have been already realised through the important labours of 
Messrs. Cowles, who some years ago attacked the subject of the ap- 
plication of electricity to the achievement of metallurgic operations 
with the characteristic vigour and fertility of resource of our Trans- 
atlantic brethren. After very promising preliminary experiments, 
they succeeded, in 1885, at Cleveland, Ohio, in maturing a method 
of operation for the production of aluminium-bronze, ferro-alumininm, 
and silicium-bronze, with results so satisfactory as to lead to the 
erection of extensive works at Lockport, N.Y., where three dynamo- 
machines, each supplying a current of about 3,000 Ampéres, are 
worked by water-power, through the agency of 500 h.-p. turbines, eigh- 
teen electric furnaces being now in operation for the production of 
aluminium alloys. These achievements have led to the establishment of 
similar works in North Staffordshire, where a gigantic dynamo-machine 
has been erected, furnishing a current of 5,000 Ampeéres, with an E. M. F. 
of 50 to 60 volts. The arrangement of electrodes in the furnaces, the 
preparation of the farnace-charges (consisting of mixtures of aluminium- 
ore with charcoal and with the particular granulated metal with which 
the aluminium is to become alloyed at the moment of its elimination 
from the ore); the appliances for securing safety in dealing with the 
current from the huge dynamo-machine, and many other details connected 
with this new system of metallurgic work, possess great interest. Various 
valuablecopper- and aluminium-alloys are now produced by adding to 
copper itself definite proportions of copper-alloy very rich in aluminium, 
the product of the electric furnace. The rapid production in large 
quantities of ferro-aluminium—which presents the aluminium in a form 
suitable for addition in definite proportions to fluid cast iron and steel 
—is another useful outcome of the practical development of the electric 
furnace by Messrs. Cowles. 
The electric process of producing aluminium-alloys has, however, 
to compete commercially with their manufacture by adding to metals, 
or alloys, pure aluminium produced by processes based upon the 
method originally indicated by Oersted in 1824, successfully carried out 
by Wobler three years later, and developed into a practical process by 
H. St. Claire Deville in 1854—namely, by eliminating aluminium from 
the double chloride of sodium and aluminium in the presence of a 
fluoride, through the agency of sodium. An analogous process, indicated 
in the first instance by H. Rose—namely, the corresponding action of 
sodium upon the mineral cryolite, a double fluoride of aluminium and 
sodium—has also been recently elaborated at Newcastle, where the first 
of these methods was applied, upon a somewhat considerable scale, in 
1860, by Sir Lowthian Bell, but did not then become a commercial 
