The prison mirror. [volume] (Stillwater, Minn.) 1887-1894, 1890-07-24
Electrical Science.
SIXTH PAPER,

Inc discovery made by OorSted and more
fully investigated by Ampere and Arago
must not be passed over in this brief out
line of the discoveries made by students of
this science.
Oersted was professor of natural philOsO-
ply at the University of Copenhagen, and
in 1919 he made his discovery, that of the
identity of electricity and magnetism. He
was lecturing to some students upon the Of
feet of heat, and to illustrate the idea more
fully he had taken battery after the style
of the VOltaic Pile and in forming the cir
cult he noticed that the needle of compass
lying upon the table detected every time a
circuit was formed. This discovery was
more fully developed by Ampere and Arago
and placed at the disposal of men of
science magnets of an extraordinary power.
Magnets are OF two kinds permanent and
temporary. Temporary magnets are made
by placing piece of soft iron within he'll
ical coil OF copper wire, and connecting
the ends of the wire to battery. AS long
as the circuit is formed the iron remains
magnetic; on breaking the circuit the iron
reverts to its non-magnetic state. Steel
Cihhdlly UhOoOOu OOCOhOO POI HdHOutAy 1d1-
netic. AS magnets enter into the cOnstruc-
ton of numberless practical apparatuses for
the use of electricity, the Importance of this
discovery will be readily seen.
The first practical telegraph operated by
means of the VOltiac Pile was constructed
by SOmmering in 1909, and was operated
with success for short distances, but never
came into actual use. SOmmering's appa-
ratus displayed great ingenuity in its con-
StructiOn. He took wooden frame and
placed in it twenty metal rods, each
marked with a letter of the alphabet, and
to each of these rods he attached wire in
Sulated from the others and twisted to-
gether. forming cable which extended to
the receiving station; here they were sepa-
rated. each passing through the bottom of a
trough with glass sides and was then
marked with the corresponding letter of the
alphabet. The trough was filled with water
and the letters were indicated by the gases
arising from the ends of the wires. When
ever current of electricity passed through
the wires it decOmpOsed in the water. In
sending message the attention of the Op-
orator was called by means of a bell rung
by clOckwOrk set in motion at the desired
moment by the current of electricity. In
sending message two letters were spelled
out at the same time; as gases Oxygen and
hydrogen) rose from two points at once.
Surprising the operator at the sending
station desired to send message; he first
calls the attention Of the receiving operator
by means of the bell and then connects the
wires of the VOltiac Pile to the apparatus
by means of two terminal pegs attached, we
will say, to the letters M and G.; at the re-
ceiving station these wires coming through
the trough filled with water, decompOses
the water, and hydrogen and oxygen gases
arise. Now suppose these terminal pegs
are differently shaped, say one an oval, the
other triangle, allowing the positive pole
of the VOltiac battery to be at the oval ter
minal peg attached to the letter Nj, oxygen
gas will arise from the M wire. The mega
tive pole of the battery is attached to the
triangular terminal peg at G and hydrogen
gas arises from this in a larger quantity
however than the oxygen. The letters are
read by placing the letter from which the
larger volume of gas arises first in position;
in this case they would read M, and so
on. the letter from which the hydrogen gas
arises taking precedence of the other. This
apparatus was afterwards modified so that
two wires could be used, thus disposing of
twenty-five wires.
The needle telegraph was afterwards con-
structed by Baron Schilling at St. Peters
burg. who made use of five horizontally
mounted needles. His idea was improved
upon by several. notably by Professor
Wheatstone in England, who made the five
needles move in vertical planes. The appa-
ratus was in form similar to large clock
with handle at the base which connected
the line wire to one of the poles of the
battery. causing the needle to move to
the right M, two to the left A, two to
the right N, three to the left B. etc.
LEONARDUS.