The mirror., 1920-01-01

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t&-AW iron, commonly known as load
stone, possessing a remarkable attractive
power for iron, and suppos d
to have been found, originally near
Magnesia, an ancient Greek city of Asia
Minor, in the northern part of Lydia, dur
ing the early period of the twelfth century,
or more than seven hundred years ago.
However some authorities differ in opinion
as to the date of it's original discovery.
It was not only discovered that the
loadstone had selective attraction for iron
but also that it endued iron in contact with
it, with it's own peculiar property, which
we will see later, was very essential in pro-
crossing the science of magnetism.
Another important discovery also was
that magnets power of attraction is not
destroyed by the intervention of other bodies
such as brass, copper, ETC., between the mag
net and the magnetic body.
The introduction of steel magnets and
the perfection to which they were gradually
brought caused the loadstone to fall into dis
use. One small loadstone, however, was
noted for its carrying power, of nearly three
hundred pounds, but the artificial magnet
minutely describes how weak magnets may be
made by means of the earth's force. 1t was
discovered that in combining these magnets
iE.o bundles or magazines and used in re-
turn to produce stronger magnets, and so on
that magnet could be produced to an enor-
nous carrying capacity of more than two
tons. (
wish to describe to you one form of an
artificial magnet known as the Electro Mag
net which is produced by the action of a
galvanic, or electrical battery.
1t consists of square block of iron,
deeply slotted with four parallel groves into
which three layers of copper wire cable are
wound zigzag fashion so that the current
converts the Aanges alternately into north
and south poles, the armature being a
square block planed to fit the face of the
magnet. This form of magnet has been con-
structed to carrying capacity of more than
four TONS
The science of magnetism has pro-
gressed wonderfully in the last century, and
if our civilized world today would be de-
prived of the use of magnetism, | am in
clined to believe that a very inconvenient
period would follow.
Probably many of you have never
stopped to consider how essential magnetism
really is but it is an important factor of our
great economies of today at least it is so
termed by our scientists.
| have not been requested to take mag
netism as an affirmative in debate but l
wish to make clear to you just how essential
magnetism really is.
For instance take our electric dynamos
from which we receive one of the greatest
economies of the world today, electricity,
were you to extract the feed magnets from
these machines they would as whole be use
less.
There are innumerable others, as,
electric motors, generators, magnetos, the
ringing magnets of our telephones, etc.
The principle of electromagnetic In
duction, upon which the operation of the
dynamo is based, was discovered by Michael
Faraday in 1913.
might add while the science of mag
netism has progressed rapidly in the last
century as aforesaid, it made but little pro-
gress until after the invention of the marines
compass Here is another invention of great
Importance of which magnetism is the base.
This instrument consists of steel
needle perfectly balanced upon an axes, or
post allowing it to revolve freely when at
tracted by magnet, the needle being mag
netised by rubbing it with the loadstone,
after which was, found to point due north
and south or in parallel with the geogra-
phical meridian.
If you have ever considered for :
moment the navigation alone that depends