THE TILLAMOOK HEADLIGHT
and all the while he was there, I never
so much as thought Qi ceremonious
dress and dinners, and liveried but
ler« and footmen; nor did It once oc
cur to me that our aimpl« kltchao
Mora, and Old John’s eon at the wheel
Ot eur eue motorcar, ware nut UauCS-
I fully and entirely adequate, so unas
sumingly and so perfectly did Jerry
Mmlstakably "fit In.” (There are Bo
other words that so exactly express
what I tnean.) Aud In the end, even
hl* charm and bls triumph were as an
Obtrusively complete that I never
thought of being surprised at the
Eleanor H. Porter
prompt capitulation of both Fsthar
and Mother.
Jerry had brought the ring. (Jerry
always brings his “rings"—und he
never falls to “put them on.”) And
Illustrations by
he went back to New York with
% H. Livingstone
Mother's promise that I should visit
them In July at their cottage In New-
J port.
They seemed like a dream—those
>t by
four days—after he had gone; and I
should have been tempted to doubt
8YNOP8I8
the whole thing had there not been
PREFACE.—‘Mary Marte" explains her the sparkle of the ring on my finger,
amu nat “double personality" ana Just and the frequent reference to Jerry
wny ana la a "crOBS-currept and a contra
on the lips of both Father nnd Mother.
fiictlon,” ah
tulla haf reasons for
writing the d
tar to bs a noval. The
They loved Jerry, both of them.
•ary Ta com
at Andersonville.
Father said he wns a fine, manly
CHAPTER X.—Mary begins with Nurse young fellow; nnd Mother said he was
Sarah's account of hsr (Mary's) birth,
a dear boy, a very dear boy. Neither
which seemingly Interested her father.
of them spoke much of his painting.
Who Is a famous astronomer, less than a
«•w star which was discovered ths same Jerry himself had scarcely mentioned
sight.
Her name is a compromise, her
mother wanted to call her viola and her It to them, ns I remember, after he
father insisting on Abigail Jane.
Ths had gone.
child quickly learned that nor home wao
I went to Newport In July. "The cot
tn some wav different from those of hsr
small friends, and was pussled thereat.
tage," as I suspected, wns twice as
Nurse «aruh tells her of her mother's ar
rival at Andersonville as a bride and how
large and twice as pretentious as the
astonished they all were at the eight of
New York residence; and it sported
the dainty elghteen-year old girl whom
tw’lce the number of servants. Once
the sedate professor had ohosen for a
wife.
again I was caught In the whirl of din-
CHAPTER IL—Contlnutag bar story, i tiers and dances and motoring, with
Sturse Sarah makes It plain why the
the addition of tennis and bathing.
ousehold asamed a strange one to the
And always, at my side, was Jerry,
cbUd and howber father and mother
drifted apart through mlaunderetandlng. seemingly living only upon my lightest
each too proud to In any way attempt to
whim and fancy. He wished to paint
smooth over the situation
UL Mary tails ef the time my portrait; but there was no time, es
Sient "out west" where the "perfectly
pecially as my visit. In accordance with
1 right and gaateal and respectable’’
vorce wm being arranged for, and her
Mother's Inexorable decision, was of
mother's (to bar) unacountabla behavior
only one week's duration.
By the cxxirt'a decree ths chfid Is Io apeml
•u months of tbs year with hsr mother
But whut a wonderful week that
and six months with her father. Boston
was! I seemed to be under a kind of
Is Mother's home, and she and Mary
leave Andersonvilte for that city to spend
spell. It win ns If I were in a new
the first six months
world—a world such as no one had
CHARTER IV- At Boston M»ry bs- ever been In before, Oh, I knew, of
oomes ■Marte.’’ Hb- Is deilghted wlfh her
course, that others had loved—but not
K’ home. so different from tn- gloomy
es at Andarsonvlll«. Tba numbsr of
as we loved. I was sure that no one
wbo call on hsr mothsr Isads
bad ever loved as we loved. And It
on tha poseiblllty of a
olaeeos ths caJters as
was so much mors wonderful than
ra.
finälly doeldlna ths
anything I had ever dreamed of—this
bo<woo« *tli« vtollntet"
Mr. Karlow. A oonvoraatloa shs
love of ours. Yet all my life since my
re botweoa teer mothsr aad Mr
eerly teens I had been thinking and
It WUI not hs
planning and waiting for It—love. And
uidereoo re-
sow It had eotne—the real thing. Tlie
ifcr"
others—all the others had been shams
........................... , . ....... . .!»»< mt that
and make-believes and counterfeits.
to expected at Andersonville for
month» »he to fa anend wffh her
At Newport Jerry decided that he
Her another to diatreaMed, but
wanted to be married right away. He
ba» no alternative, and “Marie** depart»
¿MARY
¿MARIE
A*
A*
'or Anderaonvtlle
' I
grtAFTlWt e —A« jgsBeiwenvttte Awnt
Ane meets her st the station
Her fa
ther la away somewhere
studying an
eclipse of the moon.
Marie "Mary"
BOW Instinctively compare» Aunt Jane,
prim and severe, with her beautiful, dainty
mother, much to the former's disadvan
tage
Aunt Jane disapproves of ths daln.
ty cloths» whloh ths child la wearing, and
replaces them with "serviceable" sorxee
and thick-coled shoes Her father arrives
home and seems surprised to »ee her The
child »min begins to notice that the girls
at school seem to avoid her
Her father
arpears Interested In the life Mrs. An
derson lead» at Boston and asks many
questions In
a queer manner
which
pu«<lea Mary.
She finds out that her
schoolmate» do not associate with her
on account of her parents being divorced,
and she refuses to attend school
Angry
at first. Mr Anderson, when he learn»
the reason for her determination, decides
that »he need not go
He wllj hear her
lessons
In Aunt Jane's and her fatlier’s
absence Mary dresses In the pretty clothes
she lirmight from Boston and plays rhe
liveliest tunes she knows on the little-
used piano
Then, overcome hy her lone
someness, she Indulges In a crylns spell
which her father's unexpected appear
ance Interrupts
Kim sobs out the etorV
of her uni apnlnosa, tnd In a - h may i <-
he comforts her
After that he appears
to 1
- - >
Her mother writes asking that Mary be
allowed to ■ orn* to Boston for th begin
ning of the school term, and Mr Ander
son consents, though from an expression
he lets rail Mary believes he Is sorry sb»
Is ruins
i
CHAPTER VI
Marv la Surprised at
the tenderne»» her father displays when
he pm» her on the train for Boston
flhe
discover»
"the
violinist" making
love to her mother'» maid. Theresa, but
ear« nothin«
later however »he over
hesr» him making a proposal of marriage
to her mother and tell» what »hr »aw
"The violinist" 1» dismissed
An unac
countable chamre in her mother aston
ishes her
The child 1» given to under
»lend »he 1» being taught setf-d|»<-lpllp«
and she has leas good times and fewer
Lrettv thine» to wear
As the time for
er return to Andersonville approach»»
Mis
Anderson
equip»
her
In
plain
drennea
and
"sensible"
shoe» "Marv"
things the hlld complains
»
>1
I
I
a
I
r ■-
■
■
i.
,1
CHAPTKB VII—At the Andersonville
Station Mary Is met hy her father In a
new automobile, and find» Instead of the
prim ind angular Aunt Jane a young and
-onian
who «he lenrn*
1«
attractive wrr
—
----------- '*
................
"Cousin
Grace " Mary write* her neither
of the (hangi*. amt Is aatonlshi-d at the
many questions she la called on to an
ewer c ‘oncernlng her father's new house
Marv decides that he Intends to
keeper
t ii'ieln llrace " In a moment of
mam
confide tnce she a*ke him tf that I* not
hie Intention
He telle her It Is not. and
I* diiinfminded when sh>- Infirm* him »he
hnv written to tier mother telling her her
Idea of tin- situation.
A few day» later
Mary goes back to Boston
rlLUTI-’ll VIII. Mr
And»r»on vi»lt»
Bouton to hllver a l»<*tur»
Mr* An->»
•on md Mari«* hear him »h<t Marie talk»
with him l.at»r that tint Marie find» har
mother crying over some old rtnerv in the
attic. and »lie learn» the thing* were con
net tr ' w'lh Mm Anderion*» flrat meet
in« with tier divorced husband
At a rt
tepilt n tendered l'ro(e«Hor Anderson Ma
rie lead» her father to admit that he
regret> the reparation, and Marie la »ure
that * het
mother
from 1er ohavrtationa 1 **
w
“
rggests that ha call
•till loves him
Mhe
rid . arrange
ihe hou»» and ah» wl
_ tor h»r
-j
mother to me»t him without flrat . - know
Marla la con fl
In» who the visitor 1»
dent iiv' it they meet, a reconciliation
Her Intuition la correct, mu
will follow
misunderstandings are explained
tuai
the
two.
who --------
have really
and
——- always
loved one another are remarried
CHAPTER IX.-The diary lakrs a jump
of iwelvs v».»rs, during »hl h Marls
(always Marie thsm has ths usual harm
teas l**ie affairs Inseparable from girl
hood
Tlreii sh» most» THE man—Gerald
Weston, young, wealthy, and alresdi a
au< resarui portrait painter.
They are
deeply In love and the wedding follows
quickly
With the comma of the baby
Eum.e thin«» seem to change with Marl«
• nd Gerald and they tn a manner drift
apart
X'l ew Eunice Is five years old
Matte decides to part from Gerald
In
tending to break the news to tier unit her
ah
is (»minded of her own frequently
nnlaptw childhood find how Iter action
in parting flora her husband will subl
Ktrn re to the sarnr humlllstloos
Her
•yes opened Malte gives up her Idea of
a ■et'aralten. and returns to her husband
>tei
-rtv end hsr tans
At : Newport Jerry Decided That He
Wanted to Be Married Right Away.
I good
deal to be learned later on; t
we didn’t think of that. Love th
la to last must be built upon the r-.i'
zatlou that troubles and trials and »< '
rows are sure, to come, and that th
must be borne together—if one back
not to break under the loud. We wi ■
entering into a contract, not for
week, but, presumably, tor a lLfetlnn
—and a good deal may come to , ■
in a lifetime—not all of it pleasin'
We had been brought up in two dis
tinctly different social environments
but we didn't stop to think of that. We
liked the same sunsets, and the Samy
make of car, and the same kind of i
cream; and we looked into each oth
er's eyes aud thought we knew each
other—whereas we were really only
seeing the mirrored reflection of our
selves.
And so we were married.
It was everything that was blissful
and delightful, of course, at first. We
were still eating the ice-cream and ad
miring tb« sunsets. I had forgotten
that there were things other than sun-
set* nnd Ice-cream. T suspect, I was
not twenty-one, remember, , and my
whole
'
feet fairly ached to dunce. The
world wns a show. Music, lights,
laughter—how I loved them all!
Then came the baby, Eunice, my
little girl; and with one touch of her
tiny, clinging fingers, the whole world
of sham—the lights nnd music and
glare and glitter Just faded all away
Into nothingness, where It belonged.
As if anything counted, with her on
the other side of the scales!
I found out then—oh, I found out
lots of things, You see, It wasn’t that
way at all with Jerry. The lights and
music and the glitter and the sham
didn't fade away a mite, to him, when
Eunice came. In fact, sometimes it
seemed to tne they Just grew stronger,
If anything.
He didn't like It because I couldn’t
go with him any more—to dances and
things, I mean, He said the nurse
could take care of Eunice. As if I’d
leave my baby with any nurse that
ever lived, for any old dance! The
Idea! But Jerry went. At first he
stayed with me; but the baby cried,
and Jerry didn’t like that. It made
him Irritable and nervous, until I was
glad to have h'm go.
I think It was about this time that
Jerry took up his painting again, I
guess I have forgotten to mention that
all throqgh the first two years of our
marriage, before the baby came, he
Just tended to me. He never painted
a single picture. But after Eunice
came—
But, after all, what is the use of
going over these last miserable years
like this? Eunice Is five now. Her
father is the most popular portrait
painter in the country, I am almost
tempted to say that he is the most
popnlar nun. a* wch. AH the Mrt
charm und magnetism are there. Sorne-
times I watch him (for, of course, I
do go out with him once in a while),
and always I think of that first day 1
«aw hlin at college. Brilliant, polished,
witty—he still dominates every group
of which he Is a member. Men and
women alike bow to his charm.
After all, I suspect thnt it's just thaï
Jerry still loves the Ice-creiun and sun-
sets, and I don't. That’s all. To me
there's something more to life than
that—something higher, deeper, mom
worth while. We haven’t II taste lb
common, a thought In unison, an
aspiration In harmony. I suspect—lit
fact I know- that 1 get <>n his nerve*
just as riispliigly as he does on mine
For that reason I’m sure he’ll be glad
when lie get* my letter.
But, some way, I dread to teb
Mother
•
•»••••
Well, It's finished. I've been about
four days bringing this autobiography
of Mary Marie's to an end. I’ve en
joyed doing It, In a way, though I'll
have to tvltiitt I can't see a* It's made
things any clearer. But, then. It was
clear before. There isn't any other
way. I've got to write that letter. A«
I said before, I regret that it must be
so sorry an ending.
I suppose tomorrow I'll have to tell
Mother. 1 want to tell her. of course,
before I write the letter to Jerry.
It'll grieve Mother. I know it will
And I'm sorry. I'ooj Mother! Already
she's had so much unhappiness In her
life. But she's happy now. She and
Father are wonderful together—won
derful. Father Is still president of the
college, lie got out a wonderful book
on the "Eclipses of the Moon" two
years ago, mid he's publishing another
one about the "Eclipses of the Run”
this year, Mother's correcting proof
for him. Bless her heart. Rhe love«
it. She told me so.
Well. I shall have to tell her tomor
row, of course.
didn't «nut Io wait two more endle**
yenr* until I wu* graduated. The Idea
of waxting nil tlint valuable time when
we might be togetht
there was really no
either—no reason at i
I smiled to myself, «
at Ills sweet luslstenc
sure I knew two rei
good reason«—why I
before grnduatloti. i
Father; the other rea
I hinted us much.
"Ho! Is (bat all?*' lie laughed and
kissed tne. ”1'11 run down ami see
them about It," he Mild Jauntily.
I smiled again. I lind no more Idea TOMORROW — WHICH HAS BE*
thnt nuyihlng he could «n.v would—
COME TODAY.
lint I didn't know Jerry—then.
I Imd not I...... home from Newport
I wonder If Mother knew what I had
a week when Jerry kept Ills promise conic Into her tittle sitting- room (Ins
nnd "run down " And lie hnd not been morning to say. It seems as It she
there two days before Father and must have known. Aud yet—
1 hud wondered how I whs going to
Mother admitted that, perhaps after
all. It would not lie so bad an Idea If begin, but. Iiefore I knew It, I was
I shouldn't graduate, but should be rigid in the middle of It—the subject.
married Instead
1 mean. That's why I thought perhaps
And st> I was married
that Mother—
(Didn't I tell you that Jerry always
But I'm getting as bad as little Mary
brought rings and put them on ?)
Marie of the long ago. I’ll try now to
And again I say. and so w e were tell what did haptwn.
married
I was wetting my lips, and swallow
Hut what did we know of each Ing nnd wondering how 1 wns going
otherT— the real other? True, we hail to begin to tell her that I was plant mg
danced together been swlmnilnc to not to go back to Jerry, when all of a
gether. dined togetl er played tennis sudden I found myself saying some
together Bill wh#i Hid we really know thin* about little Eunice And then
of ««eh • »t her’« whims and prejudices, Mother said:
opinions end personal habits and
"Yea. iny dear; and that's what com
taste*? I ini-« to h worn what Jerri forts me ^nost of anythlug—beeauae
would snv about a gunnel: and he you are so devoted to Eunice. You «ae.
knew I fane, w hat I would say about I havs feared sometime«—for yon and
a dream» walls song Bui we didn't Jerry; that you might separate. Rat
either of ns know what the other I know, on account of Eunice, that you
would say to a dlnnerleaa liouie with never will."
ibv cook gone We were lee »lug a
"But. Mother, that'a the very
son—I metin, It would be the renson,”
I stammered. Then I stopped. My
tongue just wouldn't move, my throat
aud lips were so dry.
But Mother was speaking aguin.
"Eunice—yes. You mean that you
never would make her go through v. Irat
you went through when you were her
age.”
“Why, Mother, I—I—” And then I
stopped again. And I was so angry
and indignant with myself because I
hud to stop, when there were so many,
many things that I wanted to say. If
only my dry lips could articulate the
words.
Mother drew her breath In with a
little catch. She hail grown rather
white.
"I wonder if you remember—if you
ever think of—your childhood,” she
said.
“Why, yes, of — of course — sorpe-
times.1' It was my turn to stammer.
I was thinking of that diary that I had
Just read—and added to.
Mother drew in her breath again,
this time with a catch that was almost
a sob. And then she began to talk—
at first haltingly, with half-finished
sentences; then hurriedly, with a rush
of words that seemed not able to utter
themselves fast enough to keep up
with the thoughts behind them.
She told of her youth and marriage,
and of my coming. She told of her
life with Father, and of the mistakes
she made. She told much, of course,
that was in Mary Marie's diary; but
she told, oh, so much more, until like
a panorama the whole thing lay before
me.
Then she spoke of me, of my child
hood, and her voice began to quiver.
You can see things so much more
clearly when you stand off at a dis-
diary, and 1 thought—what if it were
Eunice—writing that!)
She suit! I was the most devoted
mother she had ever known; that I
was too devoted, she feared sometimes,
for I made Eunice all my world, to the
exclusion of Jerry aud everything uud
everybody else. But that she was very
sure, because I was so devoted, end
loved Eunice so deurly, that I would
never deprive her of a father’s love
aud carq,
I shivered a little, and looked quick-
ly into Mother’s face. But she was not
looking at me. I was thinking of how
Jerry had kissed aud kissed Eunice a
month ago, when we came away, us if
he just couldn't let her go. Jerry is
fond of Eunice, now that she's old
enough to know something, and Eunice
adores her father. I kuew that part
was going to be tjard. Aud now to
have Mother put it like that—
I begun to talk then of Jerry. I just
felt that I’d got to say something. That
Mother must listen. Thut she didn’t
uuderstand. I told her how Jerry
loved lights aud music and dancing,
^ind crowds bowing down and worship
ing him all the time. And she said yes,
I she remembered; that he'd been
! way when I married him.
She spoke so sort of queerly
j again I glanced at her; but she
i was looking down at the hem she
turning.
I went on then to explain that I
I didn’t like such things; that I ba-
I lieved that there were deeper and
higher things, and things more worth
while. And she said yes, she was glad,
I and that that was going to be my sav
ing grace; for, of course, I realized
that there couldn't be anything deeper
or higher or more worth while than
keeping the home together, and put-
; ting up with annoyances, for the ulti
mate good of all, especially of Eunice.
She went right on then quickly, be
fore I could say anything. She suid
that, of course, I understood that I
was still Mary and Marie, even if Jerry
■ did call me Mollie; and if Marie had
' married a man that wasn’t always con
genial with Mary, she was very sure
Mary had enough stamina a\d good
sense to make the best of it; and she
was very sure, also, that if Mary would
only make a little effort to be once in
a while the Marie he had married,
things might be a lot easier—for Mary.
Of course, I laughed at that. I had
to. And Mother laughed, too.* But we
understood. We both understood. I
had never thought of It before, but I
had been Marie when I married Jerry.
I loved lights and music and dancing
and gay crowds Just exactly as well as
he did. And It wasn't his fault that I
suddenly turned into Mary when the
baby came, and wanted him to stay
at home before the fire every evening
with his dressing-gown and slippers.
)<•
Than She Spoke of Ma,
Childhood, and Her Voice Began to
Quiver.
Friday, July 14, 1
vendas
ha
vaa
aurprUsA.
lia
hadn’t married Mary—he never knew
Mary at all. But, do you know? I'd
never thought of that before—until
Mother said what she did. Why, prob
ably Jerry was Just as much disap
pointed to find his Marie turned Into a
Mary ns I—
But Mother was talking again.
She said that she thought Jerry was
a wonderful mun, in some ways; that
she never saw a man with such chnrni
anil magnetism, or one who could so
readily adapt himself to different per
sons and circumstances. And she «aid
she was very sure if Mary could only
show a little more Interest in pictures
(especially portraits), and learn to dis
cuss lights and shadows and perspec
tives, that nothing would be lost, and
that something might be gained; that
there was nothing, anyway, like a com
munity of Interest or of hobbles to
bring two people together; ami that It
wns safer, to say the least, when it
was the wife that shared the com 111 u*
nity of interest than when It wns some
other woman, though of course, she
knew as well as I knew that Jerry
never would— Rhe didn't finish her
sentence, and because she didn't finish
it, it made me think all the more,
Then, In a minute. she was talking
again.
She was speaking of Eunice. Rhe
said once more that because of her,
she knew tnat she need never fear any
serious trouble between Jerry and me,
for, after all. It's the child that always
pays for the mother's mistakes mid
short-sightedness, just as it Is the sol-
dler that pays for Ills commanding offl-
cer's blunders. That's why she felt
thnt I had had to pay for her mistakes,
and why «he knew that I’d never Com
pel my little girl to pay for mine. Sb«
said that the mother lives in the heart
of the child long after the mother is
gone, nnd that was why the mother
always had to be—so careful.
Then, before I knew it. she was talk
ing briskly and brightly about some
thing entirely different; and two m ru
ates Inter I found niyself alone mi t-
side of her room. And I hadn't told
her.
But I wasn't even thinking of that,
I was thinking of Eunice, and of that
round. chlhllsh scrawl of a diary up-
Stairs In the attic trunk. And 1 «lit
pb turlng Eunice. In the years to coine.
writing her diary: and 1 thought
whî’t if «he «hiaild have to—
L ent iinitnirs then and read that
dt: rv : :: In Ind all the while I
•
tance like this, you know, than you
can when you are close to them !
She broke down mid cried when she
spoke of the divorce, mid of the influ
ent** It had upon me, mid of the false
Idea of marrlnge it gave me. She said
It was the worst kind of thing for mo
tile sort of life I hail to live. She said 1
grew pert and precocious and worldly
wise, and full of servants' talk and
Idea*. She even spoke of that nigh
nt the little cafe table when I gloried
in the sparkle and spangles aud told
her that now we were seeing life—real
life, And of how shocked «he was.
and of how she saw then what this
thing wns doing to me. But it was too
late.
Rhe told more, much more, about the
Inter years, and the reconciliation ;
then, some way, she brought things
nround to Jerry nnd me. Iler face
flushed up then, nnd *he didn't meet
my eyes. Rhe looked down at her sew
ing. She wa» very busy turning a hem
just *<x
Rhe said there had been a time
jnce, when she had worried a little
about Jerry and me. for fear we would
—sepn rate, She si id that she believed
thnt, for her, thnt would have been the
very blackest moment of her life; for
It would be her fault, nil her fault.
I tried to brenkl In here, nnd *ny,
"No, no." and thnt It wnsn't her fault;
but site shook her bend and wouldn't
listen, nnd she lifted her hand, mid I
had to keep still and let her go on talk
ing. Rhe wns looking straight Into niv
eyes then, and there wns such a deep,
deep hurt In them that 1 Just hnd to
listen.
Rhe «aid again that It would be her
fault; that if I had done that »he
would have known that it was all he-
cause of the example she herself had
set me of childish willfulness nnd self
ish seekin* of (lersonal happiness at
the expense of everything and every
body els«*, And she said that that
would have been the last straw tn
breitk her heart.
But she declared that she was sure
.)h
no» that she need not worry 8u<*t* »
If
knew that I'd tira
thing would never be
th.it I'd never
I gm-ss I gnsped a little at this. Any
letter that I w*>
how . I know 1 tried to break In «nd
that
tell her that we were going to » |m
•
•
•
.
rate mid that that wa* exactly whnt I
ry'w etter to me i
had crane into the ro«»ni In the hr-
hat a wonder»
» to say.
write—when h
'Ml again she kept right on talking
!«»
was silenced before I had even
■ 11*1 Uiaut-
•»»>
«•» t».< a
i» a *o*nh
■'hr said bow she knew It could
irai runter amt
mik I when am 1
oe—on account of Kunlca. That crai
ing hrane?
•n d never snbject my little girl to
•
«
■ •rt of wretchedly divided life that
! wrote him tonight
• to live when I was a child.
> - she spoke I was suddenly hack ent n<—tomorrow
THE END
. cobwebby attic with little Mary's
W
THIRD ELEMENT IN
THE VACUUM TUBE
Grid Added to Fleming Valve by
Dr. Lee DeForest Was a
Big Improvement.
Any device which will pass electrici
ty in one direction and will wholly or
partially obstruct the flow In the op
posite direction is termed a rectifier,
because when connected in the path
of an alternating current it will sup
press one-half of each cycle and there
fore the circuit will be traversed by
pulsating direct current. A rectifier
also is said to possess unidirectional
conductivity, meaning, of course, that
It will conduct electricity in one di-
rection only. Its ability to rectify cur
rents of extremely high frequency de
termines its application in radio.
Due to its ability to rectify high fre
quency alternating currents the two-
element (filament and plate) vacuum
tube can be used in a radio receiver as
a detector.
Fig. VI is a simple radio receiving
circuit employing this type of two-ele
ment vacuum tube in place of a crystal
detector.
Dr.
3. A. flcmtuf at London, Bng-
land, was the first to use a two-ele-
meat tube of the type Just described
as a medium of rectifying high fre-
quency radio currents. Fleming called
his product a valve because it would
let current flow in one direction but
not in the other direction. The Flem
ing valve as a forerunner of the vacu-
um tube of today marked a very im
portant step in the progress of the
radio art. The Fleming valve, how
ever. in its original form was not much
better than other forms of rectifiers
then in use and, owing to the greater
ruggedness and ease of manipulation
of the latter, did not come into gener
al use as a detector.
Dr. Lee DeForest, an American,
greatly Improved the Fleming valve
by adding a third electrode called the
grid, which served the function of a
coutrol element and thus made It pos
sible to utilize the feeble incoming sig
nal currents to control more powerful
local currents. The three-electrode
vacuum tula» of DeForest Is the tube
used so extensively today.
The third element which is called a
grid and from which the three-elec
trode vacuum tube derives Its name
was placed by DeForeet between the
filament and the plate in the path of
the electrons. The grid Is a perfor
ated plate or mesh of fine wire through
the openings rf which the electrons
must* pass ¡n tbetr
from the
filament to the plate.
Fig. VII is a diagrammatical sketch
of the circuits of a thre^electiwde
vacuum tut-» and is Identically the
same as the sketch In Fig III for a
two-element vacuum tube with the ad-
ditlon of the grid circuit l-J-K-t
battery iu the grid circuit is
the “C battery.
As a start let us suppose thi
battery voltage Is zero. The I
tlou of the three electrode tube!
then be exactly like rhat of a twi
trode tube, Just as though therd
no grid. Like a two-electruild
when the filament C-D Is brmi|
incunijescence by the “A" batt
steady stream of electrons will h
en off, which will be drawn oi
the plate E. Plate E Is main!
at a positive potential with •
to the filament by the "B” bi
Now if the grid is made pc
with respect to the filament, it li
sible to accelerate the flow of flit
tron stream from the filament t
plate; If (he grid Is made nei
with respect to the filament, th«
of the electron stream from thi
ment to the plate will be reta
Or In other words, by making the
positive or negative with respei
the filament, It is possible to Inc
or counteract the space charge,
third electrode or grid thus oth
means of controlling the current ii
plate circuit without changing
plate potential or the filament tern;
ature.
The characteristic curve of a th:
electrode vacuum tube is shown
Flg_ VIII. This diagram shows tl
relation of grid potential to pia
current, assuming that the fllamei
temperature and plate voltage rema
constant.
It can be seen from the curve thi
by applying a negative potential <
value B to the grid, the plate eu
rent can be reduced to zero. Tlie nei
atlve charge on the grid will have th
effect of a negative potential E witi
respect to the filament, making thi
negative charge so strong around thi
filament that the electrons cannot
leave it. On the other hand, if a pool
tive potential of value F be appllec
to the grid with respect to the fila
ment. the maximum or saturation cur
rent will flow In the plate circuit. Ap
plying a cre-iter positive potential than
F to the grid with respect to the fila
ment will not cause an Increase in the
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plate current because the electrons giv
en off are being attracted to the plate
and grid.
When the grid Is maintained posi
tive with respect to the filament a
«mall current will flow In the grid cir
cuit. Because of its being positive It
will attract the electrons and have a
charge given up “to it hi them.