At the Louisiana Purchase Exposition. III: Concentrator at the Utah Exhibit

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opportunity in Salt Lake City, as it will likely be placed in the School of Mines, in the University of Utah, after the Fair closes. Editors.]

III.

THE CONCENTRATOR AT THE UTAH EXHIBIT. BY W. C. M'CARTY.

Gold, silver, copper and lead, that have rested in the same ore since the world began, separate themselves at one of the unique exhibits at the World's Fair, and seemingly of their own volition, and before the eyes of the visitor, carry themselves, in a most mysterious fashion, to compartments that man has prepared for them. There is always something fascinating about grains of bright and shining gold, and doubly so when the metal is displayed in great quantities. This may be seen in Utah's great exhibit in the Palace of Mines and Metallurgy, where, at the same time and place, may be inspected one of the most mysterious machines that the ingenuity of man nas invented. Not alone may the visitor look, but he may touch and examine at will, and even more. He will be given a quantity of the precious metal to carry away with him to do with as he will, and the souvenir is not without value.

The metal, after all impurities have been extracted, is carefully placed into small glass phials, and these are given absolutely free to visitors. All of the metal may not be pure gold. But there is gold in each little bottle, and some of the bottles contain gold that will sell for as great a sum as five dollars. The mysterious machine where this transformation of the metals takes place is called the New Concentrator, and it represents absolutely the latest and most perfect machinery to be found in mining enterprises. The machine is no toy. It is a practical thing, and does its work perfectly. It was installed at a cost of more than $20,000. Every day it may use up five tons of ore that is easily worth on the market $50 a ton, and the product is given away to anyone who visits the Utah exhibit, and will accept this unique souvenir of the Fair. The great machine, which stands 30 feet in the air, and is

AT THE LOUISIANA PURCHASE EXPOSITION. 949

built of burnished steel, copper and silver, is endowed with an intelligence in classifying ore that the human mind can never acquire. It appears to exert a secret and mysterious power over the metals, and in compliance with its wishes, the particles separate and scamper helter-skelter to the homes prepared for them. The ore that is fed into this wonderful concentrator comes from the Cactus mines owned by Sam Newhouse, in Utah, and the exhibit is made not only to show the workings of the machine, but also to show to the world the richness of the ores of that state. It has been claimed that no area of equal size in the world, can produce so varied an assortment of rich ores as can that wonderful state. The concentrator does not resemble any machine that was ever made. Long, burnished steel tubes spread out over it, and run from the top to the bottom. They cross and re-cross like the tentacles of an octopus. Through these tubes pass the ores, mingling with the water, and, assisted by it, separating and going on their way to the places assigned for them. When the ore reaches the World's Fair grounds, it is just as it comes from the mines. Barring occasional streaks of gold-bearing quartz or silver, lead or copper, the ore does not differ greatly in appearance, when viewed by the unpracticed mining man, from the limestone and sandstone quarried in Missouri and Illinois. The ore comes in chunks the size of a man's head, and even larger. Below the machine is a powerful crusher. The chunks of ore are crushed to particles which the expert in charge of the machine says are the size of ''pea gravel." The crushed ore falls into a bin, and is carried to the top of the machine, in a kind of elevator contrivance. One can look through the glass sides of this elevator, and see the shin-

ing ore in the series of buckets. The gravel is forced from the bin to the top into a big revolving, round screen, with comparatively large meshes. From this screen there are two pipes; one carries away the product that goes through the screen, and the other takes away the larger pieces, and returns them to another crusher that reduces the ore to a finer state, and frees whatever metal may yet remain. The particles that get through the screen are carried through a long, slender tube to jig No. 1, an oblong box with a false bottom made out of coarse screen. The box i

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filled with water, and a pump at one side agitates the water against the bottom, and carries the heavy and valuable metals to the bottom of the screen, while the stone and waste material are permitted to escape through a pipe, and are carried away. From this much pure metal is obtained. first jig

There are four jigs. In each successive jig, the screen at

the bottom possesses finermeshes, and the particles that go through them are smaller. The pieces that do not go through are carried off and contain nothing of value. In each jig quantities of "concentrates," as the metal thus separated is termed, are collected and carried to receptacles prepared for them. The jigs occupy space down near the floor, and each is fed from a separator that corresponds to it in number, and is perched high up in the

mysterious machine above it. The force of gravity, and the liberal supply of water, carry the crushed ore down into the jig. From the last separator, when the ore is reduced to merely sand, the product is carried down to a large table about five by eight feet. This sand, while rich in ore, was always simple waste until this marvelous machine was invented. Now every particle of valuable ore is collected and saved, and only the worthless sand is

carried away with the water. This table is the spectacular part of the entire process; here, on a slightly inclined surface, and within a few feet of the reach of the visitor, the metals all align themselves, and in the journey across the table they separate themselves and form a rainbow of color that is marvelously beautiful. The surface of the- table is covered with a dull colored linoleum. Small cleats of wood are nailed on the surface of the table, lengthwise. They reach upward not to exceed a quarter of an inch. The table slants just a trifle, and is shaken lengthwise at the rate of 240 strokes per min-

ute. The dull, colored sand reaches the table through a long tube from the last separator, and is spilled on the upper corner. A stream of water comes down through the same pipe. The vibrations of the table carry the sand diagonally across it. The water that accompanies the sand accelerates its journey. The heavier metal clings more tightly to the water-covered linoleum, and is carried the entire length of the table. The sand from which all the metal has been freed is quite light, in comparison, and takes a