The sun. [volume] (New York [N.Y.]) 1833-1916, 1916-04-02
FIG. z

came less eniclen'. The coli Vibrations
would have 10 be readjusted aud spark
plug gaps reset. The power and emf
cheney OF the motor would vary con-
siderably. Probably most every expert
euCeI motorist has been caught un-
awares with an exhausted battery when
TAR from his destination.
Modern s5stens employ an electric
generator. driven by the engine. which
keeps the battery charged 10 fun ca
pacity and maintains the maximum eff
~ticiency for ignition purposes.
IN. magnetic is another instrument
which has grown very popular and be-
Come much perfected with the growth OF
tho automunile. This instrument is de-
signed to b.. driven by the engin. FOR
tire purpose Of generating and deliver
,up current for ignition.
IN the dry cell current j. obtained
through chemical action and d.trriora-
ton of the cell elements. This is a
destructive method IN that tn" cell soon
appreciates in value. In the storage bat
t"rN current IL obtained through chem
ical %ay.iou. but thai which * taken
may lie replaced hl r%echargiug. In
brief. l., is. as the name implies. an
Instrument for storing current for use
n VIII. Will. there is some deprecia-
tiou uf In" battery. nevertheless II II
* we'll cared for - service MAJ he
extended over a considerable period Of
time. With the magreto il is different
II an electric current is passed
through a bar OF steel, such as indi-
Gated at 90" II Immediately becomes
mlgne' ized and "A permanent magnet.
II the sane current IL passed through
II bar OF soft iron of the same size the
iron becomes a temporary magnet While
current - passing. II viii not lie
come u permanent magnet For this
reason steel Of very high grade quality
Is used for magnets II the magueti2ed
steel bar "G" should be cut iutu an
indefinite number of pieces. each piece
would still be a permanent magnet, II
Is known that the earth * a
permanent magnet, having it's north and
south poles, Likewise, every permanent
magnet has it's north or positive and
south or negative pole. When steel
magnet GO is cut into an indefinite
number of parts. each part or magnet
has its north and south pole. II Is
also known that in a permauen,
magnet such as shown al &C. magnetic
lines of force pass from the north pole
to the south pole. In brief, there is a
magnetic field all about the bar OF steel,
! particularly dense at the positive and
I negative ends, The atmosphere offers
considerable resistance TO tn" lines %
force thus passing. sii for this rcasut
the magnet, II left exposed. would even
lually weaken, In horseshoe magne,s
a bar of metal is placed across the
pole pieces to conserve its strength.
NJ III is shown two horseshoe mag
nets, one above the other. This horse
shoe arrangement is carried ont IN
magnetic construction IN order to brinG
the positive and negative poles in close
,aA. -.l =. - Il
magnetic lines OF force.
Referring "a figure | let ~ note how
the magnetic lines are utilized. Al ~
IS shown soft iron pole pieces which
offer very little resistance To the mag
netic lines, These are attached to mag
nets and form the housing wherein the
armature spool ~" which Is also Of sof
iron. revOlves, This armature carries
] the wirss In . mannsr similar " tn,