Page:Popular Science Monthly Volume 88.djvu/612

 584

��Popular Science Monthly

���A farmer built a record silo tower and

now finds that a windmill on top catches

every breeze that blows

A Silo and Windmill Tower in One

SILOS have been built by the thou- sands within the last few years, but few farmers have made use of the com- liination shown in the illustration. This is a two hundred-ton silo of hollow-tile Ijlock construction wdiich supports the farm's windmill tower. The photograph shows how the silo is filled with green corn in the autumn.

The silo walls, five inches thick, are made of hollow clay blocks, with each mortar joint re-enforced by a heavy wire. The door-frame is of concrete re-en- forced with vertical rods, to which the wall-re-enforcing is tied. The roof is of concrete and metal lath, thus making the entire structure fire-proof, and wind- proof. Dead-air spaces make the walls impervious to moisture and reduce the loss from freezing to a minimum.

It is now a common practice among

��farmers to buy a twelve or f ourteen-inch cutter co-operatively and to use it on five or six jobs in a season in filling si- los. Such outfits have a capacity of from eight to ten tons per hour. One corn- binder is required in the field to keep the crew busy. Two men are employed in the field loading the cut corn bundles, and from three to five teams are needed to haul the corn to the cutting machine at the silo. This method has proved to be the most generally practised through- out the corn-belt states.

A Magnetic Machine Which Saves Waste Iron

IN order to separate the tiny grains of ore from the lumps of gravel and sand, after the final washing process, thereby saving iron that would ordinari- ly go to waste, a magnetic ore machine has been developed which may substan- tially increase the income of mining properties.

The sand, gravel and finely divided iron particles are washed through a long trough beneath which a series of power- ful electromagnets are situated. As the liquified mass slowly flows forward, the iron grains are drawn to the bottom of the trough and retained, because of the power of the magnets, against the floor of the containing walls.

���Iron in the water is caught on the magnetized

walls of the sluice-box, with a saving of many

hundreds of dollars

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