Page:Popular Science Monthly Volume 91.djvu/859

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Popular Science Monthly


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��Magnetizing Steel Without Using a Lodestone

S. J. BARNETT, of Ohio State University, has recently discovered an entirely new method of producing magnetism — the ~£

first since the finding of the ***'

lodestone or natural mag- net in ancient times, by /' means of which a magnetic field was produced in which the body to be magnetized was placed. Dr. Barnett, however, has been able to produce magnetism with- out the influence of any outside agency, by simply rotating a piece of steel at a speed of about forty-five revolutions per second. Perhaps this fact may help in the final solution of the great problem of the earth's magnetism which scientists for ages.

If a bar of steel can be magnetized by rotating it, why can't the earth produce its magnetism in the same way, as it rotates upon its axis?

In the first place he has found that a bar of steel behaves just as if its molecules were little spinning tops, or rather minute gyroscopes. These gyroscopic molecules line up with their axes parallel to the axis of rotation of the bar, and because each molecule acts as a magnet the whole bar then becomes magnetized.

The reason why the molecules act as they do has been very carefully worked out and the result seems to substantiate the now common electrical theory of matter. This theory assumes that each atom of matter consists of a positive center about which a little negatively charged particle is rotating at very high speed. From this it is deduced that each atom is a minute gy- roscope and that the nega- tive particle rotating about its axis acts just exactly like, an electric current and magnetizes the atom.



��in the electrical theory of matter, each atom is a nega- tively charged particle revolv- ing about a positive center

��has puzzled

���"Hand Over Your Watch!" Why Certainly, Mr. Burglar

WITH a revolver disguised as a harm- less watch, Leonard Woods, of St. Louis, Missouri, hopes tc rn*_ get the drop" on a burglar

> "**v,.. who has the drop on him.

When he has been asked to \ hand over his watch he will

willingly pretend to do so, \ but he will deliver a volley of hot lead instead.

The device is really a seven-shooter with a re- peating mechanism small enough to fit in the limited space of an ordinary watch- case. The encompassing of all the mechanism in such a space is a real achievement. It took Woods several years to do it. The manner in which he finally accomplished it is shown by the accompanying illustration.

The barrel of the revolver is the watch stem hollowed out. The trigger, which slides along on this stem, is placed in such a position that your forefinger naturally en- circles it when you are compelled to take the watch from your pocket. As you pre- tend to be looking at the time, you arc actually aiming at the hard heart in front of you. If the thief insists upon having the use of your watch, you car, give it to him by simpl) pressing the trigger. When that is pressed in, the cart- ridge cylinder will be turn- ed around and the hammer will be brought back until a. cartridge is in line with the barrel and the hammer is automatically released.

��The barrel of the seven- shoot- er watch-revolver is the hol- lowed out watch stem. The trigger slides along this stem

���Cyl'nder pawl

�� �