were employed 8,597 men, those over 16 years of age earning 830.80 marks per annum and those under 16 years earning 227.45 marks per annum, and 2,640 women, who earned an average of 285 marks per

annum.

The number of zinc works was 23, and they employed 6,792 men and 1,275 women, whose wages were 6,959,638 marks. The men over 16 earned 982.61 marks per annum; the boys under 16 years 277.47 marks, and the women 338.57 marks per annum. The consumption of materials was 103,669 tons of calamine, 281,289 tons of zincblende, 1,707 tons of furnace accretions, and 4,545 tons of zinc ashes. There were also consumed 1,225,007 tons of fuel and 48,085 tons of fire clay. The production was 118,522 tons of spelter, valued at 46,753,863 marks; 16,745 tons of cadmium, valued at 81,649 marks; and 1,318 tons of lead, valued at 285,634 marks.

The rolling mills employed 792 workers, to whom 645,089 marks were paid in wages. The consumption of spelter was 39,080 tons, and the product was 38,039 tons of sheet zinc, 377 tons of lead, and 454 tons of by-products, with a total value of 17,545,177 marks.

One zinc-white plant produced 1,107 tons of zinc white.

ALUMINUM AND BAUXITE.

By JOSEPH STRUTHERS.

ALUMINUM.

PRODUCTION.

The production of aluminum in the United States during 1903 is estimated at 7,500,000 pounds, as compared with 7,300,000 pounds in 1902, and 7,150,000 pounds in 1901. It has not been possible to obtain exact statistics of the production of aluminum, but judging from the extension of the uses of the metal and its alloys for such constructional and decorative work as requires lightness and no great strength, together with the increased quantity of aluminum, in the form of wires and bars, used to replace copper for conducting the electric current, it is fair to assume that the production of the light metal in the United States is steadily on the increase. This assumption is strengthened by the fact that the quantity of bauxite (the crude mineral from which aluminum is extracted) consumed during the last few years has been successively larger and larger, the consumption being based on the domestic production plus the quantity imported.

The following table shows the production of aluminum in the United States for each year since the inception of the industry in 1883:

Production of aluminum in the United States, 1883–1903.

It is to be regretted that the secretive policy concerning the development of the industry continues to be pursued by the various companies manufacturing aluminum. Doubtless a free interchange of ideas on the reduction, refining, and working of the light metal, as well as on the special practice followed in making its various alloys, would help to develop this branch of the metal industry, and in consequence benefit each and every contributor to the general fund of knowledge. The rapid and phenomenal progress in the iron and steel industry in the United States is largely attributable to the willingness of each individual manufacturer to describe and discuss his own practice, and thus, by cooperation, help the others, and in turn be helped by them.

At the present time five companies having 10 plants at different localities are engaged in producing metallic aluminum by the electrolytic process. Metallic aluminum is the sole product of the works operated by the Pittsburg Reduction Company; all of the foreign companies manufacture other electrolytic products as well.

Aluminum works in America and Europe, 1903.

The chief point of interest affecting the aluminum industry in the United States during the year 1903 was the final adjudication of the many lawsuits and counter lawsuits which from time to time have been instituted in behalf of the Electric Smelting and Aluminum Company, of Cleveland, Ohio, and the Pittsburg Reduction Company, of Pittsburg, Pa. In October, 1903, the United States court of appeals rendered a decision against the Pittsburg Reduction Company (operating the Hall patents) for infringement, since 1892, of the rights of the Electric Smelting and Aluminum Company, operating the Bradley patents. The sum involved was approximately $3,000,000. On Octo

ber 13, 1903, a friendly agreement was entered into by the two companies to the effect that the Pittsburg Reduction Company should pay a given sum for the quantity of aluminum made by it up to the date of the agreement, and should continue the manufacture of aluminum under license of the Bradley patents until the time of their expiration, in February, 1909, paying a royalty for all metal produced in the future; the operation of the Electric Smelting and Aluminum Company is to be restricted to the manufacture of aluminum alloys, although it may handle and sell aluminum in all forms at the works of the company at Lockport, N. Y. The settlement involved also an agreement by the Electric Smelting and Aluminum Company not to appeal the old case of the Pittsburg Reduction Company 2. the Cowles Electric Smelting and Aluminum Company, wherein the latter company was enjoined by the United States circuit court from manufacturing aluminum metal. By the terms of this agreement there will be no future litigation between the two companies.

The patent of C. M. Hall, covering the cryolite-alumina electrolyie, was applied for July 9, 1886, and was granted April 2, 1889; but in its specifications externally heated crucibles were described. The patent of C. S. Bradley (No. 468,148), which was applied for on February 23, 1883, and granted only on February 2, 1892, covers the invention of dispensing with external heating in such electrolytic processes by the use of a sufficient electric current to keep the electrolyte in a fused condition. The Bradley patent was proved, by a suit decided in 1897, to belong to the Electric Smelting and Aluminum Company. In the early days of aluminum manufacture, Hall, at the works of the Pittsburg Reduction Company, dispensed with the external heating of the crucible, and it was decided that by so doing he infringed the Bradley patent. The case is somewhat complicated for the reason that in 1893, as a result of an action brought by the Pittsburg Reduction Company against the Cowles Electric Smelting and Aluminum Company, it was decided by the court that the latter company had infringed the Hall patent. It now appears that neither company can manufacture aluminum by its present methods without infringing a patent which is the property of the other. However, the agreement of both companies, mentioned above, removes any possible conflict and places the manufacture of the metal on a proper business basis.

The Electric Smelting and Aluminum Company apparently now controls the electric smelting industry in the United States, as, in addition to the electric smelting of aluminum, the following companies are more or less subsidiary to it: The Cowles Smelting Company, the Union Carbide Company, the British Aluminium Company, the Electric Gas Company, the Acetylene Illuminating Company, the Wilson Aluminium Company, and the Acetylene Company.

PROGRESS OF THE INDUSTRY IN THE UNITED STATES DURING 1903.

The new plant of the Pittsburg Reduction Company at Massena Springs, N. Y., was put into operation in September, 1903. The equipment includes four 300-horsepower sets generating current at 500 volts, and provision is made to extend the works up to a consumption of 12,000 horsepower should the increasing demand warrant the outlay. The St. Lawrence Water Power Company at present supplies the electric current used in the extraction of the metal. In addition to the manufacture of aluminum, this company has installed a plant for the manufacture of carbon electrodes used in the reduction furnace, and has also a wire mill under construction.

The Pittsburg Reduction Company now has the large capacity of 17,200 horsepower, which is equivalent to 4,850 tons of metal yearly, a quantity that almost equals the combined output of the European producers.

The Pittsburg Reduction Company has two plants at Niagara Falls, N. Y., the upper one using 4,000 horsepower, near the grounds of the Niagara Falls Power Company above the Falls, and the lower one on the edge of the gorge, using 6,500 horsepower, supplied by the Hydraulic Power and Manufacturing Company. The Pittsburg Reduction Company was the first manufacturing plant to use the power of the Niagara Falls Power Company in 1893, and, as an inducement, it is understood that a contract was entered into for the supply of electric current at a cost not exceeding $18 per horsepower per year, including the installation by the power company of transforming machinery at the aluminum plant.

At the upper plant the alternating current is first passed through 12 air-cooled stationary transformers, which reduce the potential of the current to 115 volts, and raise its amperage correspondingly with a conversion loss of 3 per cent. The current then passes to six 800 horsepower rotary transformers, giving a direct current of 160 volts, with an accompanying loss of another 3 per cent. Five of these rotary transformers, running at a full capacity, furnish two currents, each approximately of 10,000 amperes and 160 volts. These currents may also be produced by running all six transformers at five-sixths of their full capacity.

The details of equipment and working of the plants at Niagara Falls, as given by Prof. Joseph Richards," is briefly summarized as follows:

At the upper works there are two lines of crucible furnaces, technically termed "reducing pots," each being supplied with current by uninsulated aluminum bars, each 12 inches by 1 inch in cross section, which can carry 800 amperes per square inch of section.

Each pot absorbs 65 volts and has a voltage drop of 5 volts. The electrodes are of carbon, 3 inches in diameter and 18 inches long, each carrying 250 amperes. About

a Electrochemist and Metallurgist, October, 1902, p. 49.