Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-11-17

WANTS WIFE WAS TIE RIAL DISCOVERED OF
NEUTRALITY-SUSPICIOUS. OF OTHERS.
The last public lecture At the Catholic Uni
versity was by Rev. Clarence E. Woodman, Phi,
D., C.SP., who spoke on the more familiar ap-
plications Of electricity in the household.
Something about electrical phenomena, he said
was known to the Greeks more than 900 years
ago. They found that Q resinous substance
cast up ON the shores Of the Mediterr aneau
would, when rubbed attract light bodies, like
thread, lint, bits Of paper. The name
of this substance. which We call amber, was
elektron; and hence that property Of attrac-
ton which was developed in it by friction came
to be called electricity. At the beginning Of
the seventeenth century one Of Elizsbeth's
physicians discovered that other substances
beside amber possessed the peculiar quality.
Az far as we know the first electrical machine,
properly so-called, was made by Otto Won
Gericke Of Magdeburg in 1850. This machine
consisted of . small sphere Of sulphur, which
was mounted on an axle and turned with q
crank. When tine dry hand was pressed against
tho sulphur globe while in rapid rotation 1t
was noticed that the latter seemed to give light
and to emit At the Same time peculiar hissing
or cracking sound.
The lecturer referred to Newton's expert
ments and to the discovery which made the
name Of Benjamin Franklin immortal.
INDEBTED TO WOMAN
For the electric battery as we have il today,
he said, we are probably indebted, as indeed
We are for most OF the good things in this world,
to a woman On September 20, 1855, the wife of
Galvani, distin guished physician Of Bologna,
finding herself in o feeble state of health
decided to treat herself to o nour ishing broth
made of frogs legs. As no rigid line seems to
have been drawn in Galvani's household be-
ho m nh a.
partments some Of these frogs legs happened
to be lying near an electrical machine with
which the doctor was experimenting and his
wife noticed that whenever spark passed to
them from the machine the muscles would at
once contract, as though thrown into strong
convulsions. 1t was afterward found that
whenever the muscles and nerves of the frogs
legs were touched by pieces of two dissimilar
metals the legs would contract as before. -
Galvani supposed that the animal was itselsf
the source Of the electricity and that tho piece,
of metal acted only as conductors. But Volta
professor in the University of Padua, who
had been much interested in Galvani's disc5v-
cry, proved that the origin Of the electricity
themselves but in the metals which touched
them. This led to the construction of the
voltaic pile, the first form of battery.
DR.. Woodman described in great detail the
method of working the various forms of cleo
trio batteries, with their successive improve
closed-circuit batteries, such as are used in the
telegraph and telephone, and the open circuit
which is more suitable for electric bells and
other household uses.
PRACTICAL APPLICATION OF ELECTRICITY.
Having thus described the source Of the
electric current he went on to speak Of the
methods Of applying 1t to practical use. After
Davys experiments in 1906 there was nothing
Of importance learned until 1908, when
Oersted OF Copenhagen announced that the
conducting wire Of q voltaic circuit acts upon
a magnetic needle. and that the needle tends
to set itself at right angles with the wire car
rying the current This was a discovery Of
the utmost importance and a French scientist,
Ampere, set about investigating its laws. He
observed that whenever a wire through which
a current Of electricity was passing was held
over and parallel with O magnetic needle
which was free to move, il Q current was
moving toward the north the north-seeking
west, and that the angular displacement de-
pended upon the strength Of the current
Thence originated the galvanometer, the basis
OF all exact measurement
Everybody knows what magnet ia and what
are its properties. Nicander relates that among
the shepherds Of Mt. Ida was one named
Magnss, who noticed that the iron tip of his
shepherds crook adhered to certain Of the
rocks. Some have supposed that the name
magnet is derived from the name Of this
snepnerQ. But IL ID generally believed that
the term comes from the ancient city Of Mag
nesia, in Asia Minor, near which that peculiar
ore OF iron was found, now called magnetic
by mineralogists, and lodestone in popular
speech. Sir Isaac Newton is said to have had
in his finger ring q small lodestone, weighing
only three grains, which would lift 750 grains
$50 times its own weight. II a steel rod is
rubbed upon such natural magnet it becomes
itself magnet, and it is with this form that
most Of us are familiar. The most plausible
theory of the nature Of such permanent mag
nets as we have been describing is that of the
French academician, Ampere. This theory as
sumes that every molecule Of magnetiZable
body is surrounded with an ever circulating
current, that these currents revolve around the
molecules Of the body in every possible direc-
ton, SO that they ordinarily neutralize each
other; that by the act OF magnetization these
currents are made to circulate more or less in
the same direction that the completeness Of
the magnetisation Is measured by the COM
pleteness with which these currents are made to
circulate; that the resultant of all these MOLE
cular calculations is the same as if one current
circulated completely around the magnet like
q wire spiral, and that in soft iron these cur
rents remain circulating only as long as the
magnetizing force is present, but that in hard
steel they remain permanently SO circulating
THEORY SUPPORTED BY FACTS.
Ampere's theory 10 supported by some re-
markable facts. In 1925 VIM. Spurgeon Of
Woolwich, England discovered that IL wire
were wound around a piece Of soft iron and
the current Of electricity were sent through
the wire the soft iron would become a true
magnet but would retain its magnetization