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and other interior States, Dr. David T. Day, Chief of the Division of Mines of the Geological Survey, established at Portland, Oregon, an experiment station, where, with an equipment comprising all the various types of machines that could possibly be of use in such work, he and his assistants have been testing the various samples and evolving the best and most practical methods of handling such material. The experiment station was first established early in the summer of 1905 and the work is still actively in progress.

From the very outset the results were both gratifying and surprising. The government investigators not only found platinum in quantities that exceeded their expectations, but they discovered that the black sand or sediment was rich in many other valuable substances, notably gold. In some instances it was evident that a given deposit was well worthy of treatment merely for the extraction of one or two minerals, as, for instance, a large shipment of the sand from Humboldt County, California, which showed an

assay value of $1,000 per ton in gold and platinum alone, while in other cases it was demonstrated that, though the sand could not profitably be handled for any single component part, it was well worth treatment if arrangements were made to save all the different mineral substances it contained. In other words some deposits are not rich enough in either gold or platinum to make it pay to work them, but, if the magnetite, chromite, garnet, monozite and quartz which they yield are also conserved, the net result is to make the venture a highly profitable one.

Dr. Day and his assistants have accomplished such wonders on the Pacific Coast that the government has hastened to broaden the scope of the work and an experiment station has been established at Chapel Hill, N. C., for the treatment. of the low-grade gold deposits of the mid-Atlantic and Southern States. Another experimental plant or "concentrating pavilion" will be installed at the coming Jamestown Exposition in order that the public may be treated to practical object lessons regarding the fruitful new

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ANOTHER TYPE OF CONCENTRATING MACHINE, FOR HANDLING LOW-GRADE GOLD DEPOSITS.

method of utilizing supposedly useless deposits.

The process followed in the extraction of the mineral wealth is the same, in the case of all deposits of sediment or black sand handled at the government experimental plants. The sand first enters a "feeder," after which it is elevated by a belt conveyor and delivered to a screen. Next the material passes to a revolving, mixing, distributor, from which it is piped to the different concentrators. This method insures an even quality of pulp for all concentrating machines. After passing over one or another of the concentrating tables the material for examination is placed in a drying furnace, where all the moisture is expelled. The pulp, when thoroughly dried, passes

through a magnetic separator, where the magnetic elements are extracted.

The concentrators which play so important a part in this ingenious new method of mining may be popularly described as quivering tables, oblong or circular in form, over which there pours perpetually a stream of water. The surface of the table is covered with grooves or corrugations of rubber or metal. When the gold bearing sand is placed upon a concentrating table the rush of water carries off the clay and other worthless material while the particles of mineral, being heavier, sink to the bottom and lodge in the riffles. The constant trembling of the table serves to concentrate these mineral particles and bring them to a common point of discharge.

Song of the Engine

'LL sirg you an engine's song; I am the master of all

Yet I was planned by the hand of man, molded and reared by him. Tireless, faithful, true, speeding to duty's call,

I bend to my task, let come what may, determined, staunch, and grim.
Mine is a song of pleasure,

For sweet is the wage I earn,
And sweet is the rhythmic measure
Of the wheels my forces turn.

I am the force of the world; its wheels are as children's toys,

For I with my strength can move them all at the touch of a lever bar; And mine is a monster's strength-there lie my glory and joys

The strength of my arms is the strength of steel-throbbing, coursing far.

And sweet is the song I sing,

For I sing that man may live,
And sweet is the echoes' ring
That my children's voices give.

Master of man am I-yet I hark to his every word

Giving the soul of my life to him in his endless quest for gold;
Tireless, faithful, true, his command like a soldier heard,

Forever I toil by night or day, till time and the world are old.
Giving my strength, my life,

To man in his quest for gold;

In the struggle and stress and strife,

Till time and the world are old.

THE MILWAUKEE SENTINEL.

VIEW OF SAN PEDRO BREAKWATER FROM SHORE END.

The trestle work off shore for 1900 feet is temporary, built to carry the track of the construction railway.

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A

Creating a New Harbor

By N. A. Bowers

T San Pedro, thirty miles south of Los Angeles, California, a great stone breakwater, more than a mile and a half long, is being built out into the Pacific Ocean. It will cost nearly three millions of dollars-furnished by the national government-and, when it is completed, the only safe and commodious harbor between San Francisco and the Mexican border, a distance of 500 miles, will be ready to handle the great traffic of the rapidly developing Southwest. Already a new transcontinental railroad has made its terminus at Los Angeles and the port of San Pedro is almost certain to become one of the great natural gateways to the Orient, while lumber and other products of the north will be brought to its docks in huge quantities.

San Pedro has long been an important seaport of the Pacific coast; but of late years its steadily growing lumber trade has been seriously hampered by a lack of ample sheltered anchorage. The rapid development of Los Angeles and the adjoining country has created a great demand for lumber; and this lumber, which is obtained chiefly from the Puget Sound

region, can be brought by water far cheaper than by rail. San Pedro had only limited wharfage, and absolutely no sheltered anchorage; but, like many engineering projects of great magnitude, a breakwater was considered impossible or impracticable until it became a necessity.

Congress discovered in this situation a real need for its assistance, and decided to build a government breakwater as the starting point for the making of a great seaport. After long delays, a contract for the construction of the breakwater was let to a Chicago contracting firm. The contract called for a V-shaped structure 8,500 feet long, to be to be built of granite and sandstone. The agreement specified that for the substructure (that part of the structure below low-water line), onethird of the rock must be of a size ranging from 100 to 1,000 lbs.' weight; onethird must weigh between 1,000 and 4,000 lbs. ; and the remaining third must be stones of a weight exceeding 4,000 lbs. In the superstructure (that part of the structure above low-water which is set carefully in tiers), no stone could be placed on the harbor side of less than 3

tons' weight; and on the sea side, no stone weighing less than 8 tons. The contractors agreed to furnish, and to put in, the rock of the substructure, for $0.541⁄2 per ton, and that of the superstructure for $0.72 per ton.

San Pedro was jubilant over the first step toward the realization of her hopes; everyone knew the details of the contract, and the preparations for bringing the first rock were watched with interest. Buoys were anchored at intervals along

$0.84 per ton for the substructure, and $3.10 per ton for the superstructure. The granite is, however, of a better quality than that used before. It comes by rail from Casa Blanca, Riverside county, 100 miles from the site of the breakwater. At the quarries the rock is loaded on standard flat cars, which are hauled directly out onto the trestle at San Pedro. Here the heavier pieces are handled by cranes. The cranes are merely very large, 90-horse-power steam shovels, with

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the line of the breakwater; and on April 27, 1899, the first barge of rock from Catalina Island, twenty-seven miles to the southwest, made fast to a buoy and dumped its cargo. Things worked well for a time, and soon 80,000 tons had been deposited. Then the contractors were unable to get the rock out as fast as before, and there was trouble ahead. After some parleying, the contract was declared forfeited in March, 1900.

This was, of course, a damper on the bright prospects that had encouraged San Pedro; but in June, 1900, the contract was relet to the California Construction Company, and work on the breakwater was resumed. By the new contract, the Government was charged

specially rigged booms and hoisting tackle substituted for the shovels. The rock for the substructure is swung out over the water, and, when the boom is in the desired position, the stone is released by means of a trip chain. The regular shaped blocks used in the superstructure are carefully placed and fitted.

The building of the superstructure is by far the most interesting feature of the work. A section of the top of the substructure is first brought carefully to the required level (mean low-water mark), and then a monster block of granite weighing from 8 to 25 tons is lifted by the powerful arm of the crane and lowered into place. The stone is first placed in its approximate position to see how it

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fits. If it does not rest quite level or is a trifle too high or low, it is raised again, and the smaller stones of its bed are rearranged. A ponderous block may thus be placed three or four times before it is left in its final position. The elevation of the stringer along the trestle is used as a datum plane, and, by means of a measuring pole lowered from above as each stone is placed, the upper surface of a tier is kept level and regular. The stones of the bottom tier on the sea side can be placed only during calm weather at low

tide. The men must work in one or two feet of water part of the time, and even in the mildest weather they are frequently drenched by a playful wave. Then, too, there is considerable danger from broken chains and falling stones, so that on the whole it is rather difficult to keep a full gang of men. But the present

contractors seem to know how to handle these matters, and in spite of many difficulties the breakwater is steadily growing.

As the massive walls of the super

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