The mirror. (Stillwater, Minn.) 1894-1925, 1921-04-28
A TRUE WORLD MYSTERY
CONTINUED from page y

Europeans had not known of the compass
very long, although the ancient Greeks
knew the loadstone. Europeans had used
the magnet chiefly in work on land and
had had no occasion to regard its varia-
tons as important or to try to find the
cause of them.
Many superstitions, some of which per-
sisted to modern times, grew up round the
compass. One was the garlic exercised
baneful influence over it,-sailors when
using it were not permitted to eat onions,
and that in many subtle ways it could
be falsifed. Falsifying the compass was
long an offense punishable with death.
Another superstition was that somewhere
there existed a great mountain of load
stone, powerful enough to draw the bolts
from the sides of ship. Sailors feared
the mountain as they feared the Flying
Dutchman.
OF course no such mountain existed,
though there are many places where there
are heavy deposits of loadstone, or mag
netite, from which magnets are made.
One of the most notable is at Magnet
Cove, Arkansas.
Just why magnetism has peculiar love
for magnetic and in less degree for all
forms of iron and little for most other
metals and virtually none for wood or
for the bodies of animals, no one has been
able to explain.
Men of science say that the polarity"
of the magnet-that is, its tendency, when
free, to point northward and southwark
is owing to the earth itself being mag
net or acting as one-the earth, that is,
is magnetized just as toy magnet is, but
not nearly So strongly; and the magnetism
that bathes and perhaps permeates the
earth GIBBS and flows in most astounding
ways.
Secular" change, or that variation in
the flow of terrestrial magnetism which
runs through long centuries, was first
pointed out by Henry Gellibrand about
But although the secular changes are the
ones that give the investigator the most
concern, there are others almost as curious
Hence, when a surveyor or navigator is
called upon to use the compass with the
greatest possible accuracy he must consi-
der even the time of the day; for there
Ios1x hx,
the sun or by the movements of the earth.
He must also consider the season; for
there are variations that merely run the
course of the year. There are slight var
iations even that are peculiar to the
month, and that may be caused by the
moon. "Nearly three centuries have
passed." says scientific pamphlet issued
by the United States Coast and Geodetic
Survey, "and, although observations have
been multiplied, and some of the best
minds have given their undivided atten-
ton to this most striking fact of the earth's
magnetism, the riddle is still unsolved."
In addition to all the other variations,
there are variations, that work arbitrarily,
apparently without rule or reason. For
example, there are magnetic storms" that
are as violent in their way as the worst
thunderstorms. Unless you happen to be
using compass or a telegraph key at the
time you never notice them; but they
often make the compass temporarily use
less by causing the needle to behave as if
it were mad and sometimes they make
telegraph wires unavoidable for hours.
Little is known of the causes of those
storms" They often have some relation
to sun spots and northern lights, or dis
plays of the aurora borealis. They are
concurrent sometimes with earthquakes;
one of the worst magnetic storms of recent
years occurred while the eruption of Mont
Pelee was destroying St. Pierre.
But there are magnetic storms when
there are no visible sun spots, and when