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COPPER

a marked effect upon Irish agriculture, for the supply of such things as fertilizers and feeding stuffs at reasonable prices has created demand for them. The supply associations also perform an impor- tant function in providing agricultural machinery which the individ- ual farmer could not possibly afford.

The example and success of the Irish Agricultural Organization Society led to the creation of similar movements and kindred so- cieties in England and Scotland. In 1918 there were in England 237 supply societies with a membership of nearly 40,000 and a turnover of 4,670,000, and 39 dairies with a membership of over 5,000 and a turnover of nearly 1,500,000. In 1918 the total number of all societies in Scotland was 170 and the membership over 8,000.

In Sweden, Norway, and Finland the development of agricultural cooperation has been very rapid. In Sweden organized cooperation dates from 1906 when the " National Union of Swedish Agricultur- ists " was formed. This union acts both as a supply and a marketing organization. By 1910 the union had 42,000 members and a turn- over of over 1,000,000, while there were 19 provincial and 940 local associations for supply and marketing; there were also 477 cooperative dairies. The development in Norway has been as great and even greater, and in 1913 there were 660 cooperative dairies and 1,344 'oca' supply societies. Norwegian agricultural cooperation is remarkable for the highly organized system of federation among both productive and supply societies. Norway and Sweden re- semble Denmark in the fact that agricultural cooperation has de- veloped and succeeded with little or no reliance upon cooperative credit. Finnish agricultural cooperation is remarkable for the way in which the various forms of cooperation, credit, supply, production, and marketing have developed. This can be seen from the increase in the turnover of the various types of societies from 1903-13:

Dairies Banks

Supply

1903

>t*

1913

it*

140,000

8,000 80,000

1,480,000 356,000 480,000

The success of agricultural cooperation in Siberia has also been extraordinarily rapid. Cooperative butter-making associations were first started about 1900, and in 1908 the Union of Siberian Creamery Associations was established with 12 affiliated societies for the purpose of both marketing and supply. By 1914 the union had over 1,000 affiliated societies and a turnover of about 1,000,000.

BIBLIOGRAPHY, GENERAL. C. R. Fay, Cooperation at Home and Abroad (1920); L. Smith-Gordon and C. Obrien, Cooperation in Many Lands (1919).

CONSUMERS' COOPERATION. E. Aves, Cooperative Industry (1907); G. J. Holyoake, History of Cooperation (1875-9, new ed". 1906); History of the Rochdale Pioneers (1893, new ed. 1900); Co- operative Movement of To-day (1891, new ed. 1896); P. Redfern, The Story of the C. W. S. (1913); The Consumers' Place in Industry (1920); Catherine Webb, Industrial Cooperation (1904); Mrs. Sidney Webb (Beatrice Potter), Cooperative Movement in Great Britain (1891, 1893, 1904); Leonard Woolf, Cooperation and the Future of Industry (1918, 1919, 1921); Socialism and Cooperation (1921). See also the reports and publications of the Cooperative Union and Cooperative Wholesale Society.

PRODUCERS' COOPERATION Benjamin Jones, Cooperative Pro- duction (1894); C. R. Fay, Copartnership in Industry (1913); Berna- dot, Le Familistere de Guise (1892); Dallet-Fabre-Prudhommeaux, Le Familistere illustre (1901).

COOPERATIVE CREDIT. Morman, The Principles of Rural Credit (1915) ; H. W. Wolff, People's Banks (4th ed. 1919).

AGRICULTURAL COOPERATION. G. Radford, Agricultural Co-operation and Organization (1917); L. Smith-Gordon, Cooperation for Farmers (1918); H. W. Wolff, Cooperation in Agriculture (1912).

(L. W.*)

COPPER (see 7.102). The industrial history of copper after 1910 was more important, both technically and economically, than for many decades previously. A very large part of the world's supply of the metal came after that date from deposits so low in grade that they could not be worked under the conditions of 1905. The major developments in this progress were the enlargement of the scale of operations in individual units of stupendous capacity; immense reductions in the cost of mining by the introduction of the caving system and steam shovelling; reduction in the cost of milling and increase in the extraction of mineral by the introduction of the flotation process; reduction in the cost of smelting by the application of coal-dust firing to reverberatory furnaces and the successful operation of basic-lined converters, and finally the development of processes for the hydrometal-lurgical treatment of certain ores and the direct production of refined electrolytic copper.

These developments were to a large extent both the inspiration toward the exploitation of the " porphyry " deposits, and the

consequences thereof. The porphyry deposits are more correctly described as fine disseminations of copper minerals through large masses of igneous rock. The economic characteristics of these deposits were mainly their large size and their occurrence at or near the surface in substantially horizontal positions. Fine disseminations of copper had been exploited for many years in the Lake Superior region, but there the copper occurred in its native form and the mineralization was in lodes dipping steeply. Previous to 1905 the occurrence of immense masses of rock, containing about 2 % of copper in sulphide form, was known in Bingham Canyon, Utah, at Ely, Nev., and else- where, but it was not believed to be possible to exploit them profitably. The conception of profitable exploitation by taking advantage of improved methods in mining and the prosecution of operations on a previously unparalleled scale, was due especial- ly to Daniel C. Jackling (b. 1869) of San Francisco. The provis- ion of plant and equipment for carrying out that conception called for immense ventures of capital ($10,000,000 for single enter-' prises), and this at a time when success was problematical. Production by this new group of mines began about 1907, but it was not until about 1910 that it assumed large proportions and the success of the new enterprises began to be clearly recog- nized. The idea at that time was to work sulphide ores con- taining about 2% of copper, but in the short space of the 10 years following it became possible to work ores containing but little more than i% of copper. The brilliant success of the porphyry copper mines and their ability to produce the metal at a very low figure stimulated the operators of lode mines, most notably the Anaconda Copper Mining Co., at Butte, Mont., toward improvements in methods in order to permit them to meet the competition of the porphyries.

Mining Processes. The following are the major advances made during 1910-20 in the arts of mining and metallurgy:

Steam Shovelling. No detailed description is necessary, for the steam shovels and general methods are substantially the same as are used in any excavation work. In their application to the mining of copper-bearing ore, the latter is broken down in benches, a line of holes being churn-drilled back of the face, charged heavily with an explosive, and the ore blasted down in quantities of many thousands of tons. The steam shovel is moved along a track at the bottom of the bench and picks up the broken ore, transferring it to cars alongside. Excessively large boulders are broken up by block-holing and blasting, but the steam shovel can pick up very large pieces, its dipper being as much as 8 cub. yd. in capacity. The largest steam shovels weigh 325 tons and dig 300 cub. yd. (place measure) per hour. This method of mining is so cheap per ton of ore that it can be applied economically even when it is necessary' to shovel away IOO or 200 ft. of worthless overburden in order to uncover 100 vertical ft. of ore. The process of removing the overburden, tech- nically known as stripping, necessarily precedes the actual min- ing. The laying out of plans for the working of a mine in this way and the figuring of the various factors furnish complicated engineering problems.

Caving. When the overburden is too thick, or is too thick with relation to the thickness of the ore deposit, mining by the caving system is adopted. In essence this system consists in opening permanent galleries under the ore body. Raises to the ore body are then made, and sub-galleries of relatively small size are driven into it, with the purpose of so undercutting the ore body that its support by rock pillars is reduced to the minimum. Finally the pillars are blasted out, causing the superincumbent ore to settle in a great crushed mass. The crushed ore is then drawn off through chutes, previously prepared, into cars in the main galleries. This operation proceeds through the ore body section by section, the natural surface over the mines settling as the ore is drawn off. There are many modifications of this system of mining, but its application to large lat-lying ore deposits is substantially as described. Modifications of the caving system of mining are also applicable in many lode nines, when the lodes are of large size. It is a very economical sys-

em of mining owing to its reduced requirements for labour, ex-

plosives, timber, etc.

The Flotation Process. Copper ore as mined at the present time contains generally only a small percentage of copper mineral, which s obtained by crushing the ore to such fineness as to liberate the mineral particles and by separating these from the worthless gangue by mechanical processes, commonly performed by washing, in which advantage is taken of the difference in specific gravities. Although there had been great improvements in the processes of ore dressing, the losses of valuable mineral continued relatively high up to 10 years ago. In the flotation process advantage was taken of the discovery that when ore suspended in water was mixed with a small