St* was In til* bis squattori ttracfacd arms to a twinkling, waaptoX acntast bis breast "This nSfbt's work,” said MseKeth «*»• itJTad almost bayood speech, “won't pass ontsJdc the few wl It And Polly—look up, child, to tell you somethin? " In silence she dared a tlmli at him. “While you—you were—as)sep—just Bow. Mr. Pereira! and I made arrangeits with your father to flra him k." MacKertxle it please your 'Awful much.” she slyhtd; that aba tanwd and looked at Bishop, standing wait hat about Larry r aha mrmurad “Pear, poor Larry” help him, too," Marcos spread

Tkere'e Lye Braeper.” she slphed jaln. “He ain’t pot many friends Lye ain't!" r*s laugh seat a seal relief orer the plootay group. ~Tn*n Lye Braeper. too." be axeialmad. “usd any other squatter who

a. Uke Granny Hope said oace,” she said shyly. Tm thankin' you. sir. an’ I—Tm hopin' the Uttle ooe God's seedin' In the snmmerU look

mu

THIRD ELEMENT IN THE VACUUM TUBE

dltlon of the grid circuit 1J-K-L. Xha battery In the grid circuit U called

the "C" battery.

As a start let us suppose that “O’ battery voltage Is aero. The operation of the three-electrode tube weald then be exactly Uke that of a two^ee* trade tubs Just as though there were no grid. Like a two-electrode tuba when the filament C-D la brought te Incandescence by the “A" battery u

steady stream of alactrpas will be gla- 1

an off. which will be drawn orer to the plate K. Plate E la maintained at a pasture potential with respect te the filament by the “B” battery. Now If the grid Is made posltlre with reopect to the filament It la possible to accelerate the flow of the electron stream from the filament to the If the grid is made negaUre with respect to the filament the flow of the electron stream t.nm the filament to the plate win be retarded. Or la other words by making the grid

fare the circuit will be traversed by poslUve or negative with respect to pulsating direct current A rectifier the filament It Is possible to Incrteea also U said to possess unidirectional or counteract the specs charge. The conductivity, meaning, of course, that third electrode or grid thus offers a It wiu conduct electricity In one dl- means of controlling the current in the

Grid Added to Fteming Valve by Dr, Lee Deforest Was a

Big bnmvement.

Any device which wfll pass electridtj In one direction and wUi wholly or partially obstruct the flow in the opposite direction Is termed a rectifier, because when connected In the path

It wUl sup-

sly. Its ability to rectify curextremely high frequency derudaM Its application in radio. Dee to Its abllitr to rectify high fre-

tabe can be used le a radio recatesr es a detector. Fig. Vi Is a simple radio receiving circuit employing this type of twtveieent vacuum tube la place Cf a crystal Meeter. Dr. J. A. Fleming of Loodcn. Erj

t tube of the type jest daoeribed as a medium of roctifylBf high freqaency radio currents. Fleming called prodact a valve becsBM It would

t yon to feel sorry for me. -An' gettin' Daddy Wee Jerry back Is Every day 1*m In Jail I'll be prayin' youH be happy." She strangled at the r of Old March words, TU get xt bossy 1" Hobart, stung with reux his disbelief la her. picked her her father's arms. When be had piaead la a dsrll ug. were beard the Me leaked towesd Lorry Biat.qv csaWiaf as If he did tm remember ■Aad wuhe forgotten It, too.” Mac Sonrio boomed la »<>aldr*l have been any great loss if my wbotn family had been sunk in the Inks. We were all more wicked any <me It the Silent City. But tonight ITS different !” Peliy etrslghtentd up. bar eyes brilliant with qaeetlonlng. *t>MUfy." aha aMwd, -does haels't gala' tv JaU for sbj Ufa-

The characteristic curve of s t

Fig. VTU. This diagram snows the raUtion of grid potential to piata

temperature aad pltte voltage r

It can be seen from the curve that by applying a negative potential of valne E to the grid, the plate cur-

ative charge on the grid wfll have C

respect to the filament, making the negative charge so strong areas! the filament that the riectroua cannot leave it. On the other hand, if a pooltire potential of valoe F be eppUo*

1th Just Uke Granny Hope said. Daddy" Pollyop went on. the velvety brown »ofuming the misty eyes. “She said. Granny Hope did, that love's bigger an' brtter'n bate any day. An’ true, ain't ur “Tap." nodded Hopkins, smoothing her face with one great hand. “I guess so. brat!”

Then be looked at Jeremiah. "May I have her suae day. sir?” be tked In reverent toaaa. Ill n her so happy you wont regret It.” ' h big frame shook. Poilyop, ever devoted to him. klaeeO 1m tenderly. “TU never leave you. Daddy darlta'. precious old Daddy,” she cried. "M«bbe—" 8hq looked up at the tall standing by her. “Mebbe.” she peated. “you'd take Jerry an' Daddy bub? They're awful good an' never get In anybody's way." “And Jerry end your father Robert, in an 1 can have year Uttle girl. Mr Hopkins, cant ir “Yep." whispered Jeremiah, sighing bearHy. Then while Robert i Polly good-night Jeremiah, with faraway look upon bis face, gathered the bow-legged child Closer to iy to and fro. [THE END.]

/f 8*#ery

rtyure YE

am tube of today -marked a vorv tmp la the progress of the radio art. The Firming valve, however. la K« original form was not much ether forma of rectifiers aad. owing l” the groaur and ease of manipaletioc

grid, which served the function of a

mtroi more powerful The throe electrode vacuum tube of DeFores. is the tube used so extensively today. third dement which Is culled a grid and from which the three-elec-trode vacuum tube derives Its name was placed by DeForesi between the filament and the piste U. the path of The grid Is a perforated plate or mesh of fine Tire through the openings of which the electrons must peas In their Journey from the filament to the plate. Fig. VII Is s diagrammatlcal sketch of the circuits cf a three-electrode Is Identically the in Fig. 1H fo- a tube with the

ment. the maximum or euturatlou cmront will flow in the plate circuit. Applying a greater positive potential than F to the grid with respoc: to the filament will nut cans.- an Increase In the

plate current because the electrons given off are being attracted to the plate and grid. Wbeti the grid la maintained podtive with respect to the filament a ■maM current will flow in the grid df> cult. Because of Us being peattlve M atoaet the elactreu* and have a