ONDR BOK OF THE HOW AND WY OND THE
By Jerome J. Notkn, Ed. , Scece Supevisor, Sufolk County, County, NY ad Sdne Glkn, M.S. Ed., Techer, New ok Ited b Rert Pateron and Charle Bnad
Edited under the supervison of Dr. Pa Paul ul E. Backwood Backwood,,
Wasington, D. C. Text and Text and ill illus us trat traton ons s ap app prove roved d by
Oak akes es
A.
Whi hi te te , Brookl Brooklyn yn C Cdr drn's n's Museu Museum m ro rookl oklyn yn New New Yor
WO BOKS
•
W O
A Divisi f GROSST & DUNA, c
IN TRO TROUC UCION ION When a town stands still for eight eight hours, is mssn somethn mighty portant. Oe such town stoo sl bcause the electrcty stoppe. Ths was ot inconvennt inconvennt for everoe, but t make a bo name Mke an h ste Susan Jane tin about it. They were lle wt questons: What is electrct? How o we ake electrcty? How oes electrct et to our town? Just as ke an his sster explore the woners of eectrct wt he ather, so ll inisiive cilre everwhere get answers to their ueston about electrcit te rea his boo. Like the others n the n Why ner ri, t ece b is authentic an clorful an can be wth ntrest by the whle fai. The answers o qutis abt elecrict that are now easy to ie yong people a the aners whic sretche the mins of the greatest children Forunately, runately, book bookss give children hunred years ago. Fo scientists less than a hunred the weah o nformation whch took so long for scentsts to scover. wich aree the speca specall paths w imentng ar ing and exper experimentng g, investigat nvestigating Thnking, Thnkin doze n experthan a dozen nclud es more than book, ok, whch whch ncludes e. Ths bo scie nce. are bas bascc to scienc on n before, before, will a othess have o rs dscover dscover what othe to help reade readers ments to scoo an excellet excellet aton t the scoo hs. It is an paths. ren alog thes thesee sae pat chldren chld s pants raders ders an ter pant o young ra scenc books o collecton o scenc ome ome collecton
Paul Backd
Blackwoo Dr. Blackwo od is professional professional em employee in the U S Oce of Education Ts book Ts book was was edied edied by him him i i his rivate rivate caac caacity ity nd nd no ofcial ofcial supor supor or enorement enor ement by the Oce of of Euation Euation i intende intende or should sh ould ine ine. .
Library of Cngress Clg rd Numer: -578
7 Pintng Coprgt © 1960, 1969 by Gsse & Dl, Inc A rihts reserved der tertoa a P-Aerca oprgh ovenos Pbsed smuaeous n ada. Prted n th" Ued Ses f erc.
ONTNTS
Page SIL SOO OO D SIL OWN WN S THE DAY HE O THE
Why is the mi eletri cble the ifeine of a o instril town How r e peent upon electricity
4 5
WT S THS MGCAL THNG CLLE ELECTRICTY 6 In wht ys does waterfl serve us Wht re some of the wys we know of to 7 mae electricity What in o power is used to run s s? 9 What ms the genertor spin rond Wht prt oes the stem py in this ex 0 eimet 10 In what wy e eectrons pshed Why is e lld a portbe power st ti IGWAYS T CRY ELECTRICTY ow does a trnsformer help us get electricity to or homes Why is copper most commony used for ectic wiring Why don't we use copper wires n or toaster C yo name three electric things i your home tht use poo conctors ELECTRICITY IS RELLY FRS COUS O MGNTS re mgnets and eetricity reted Wht hppens whe electity flows throh wire Wht hppes when a mnet moves inside coi of wire How is a switch ie door
14 14
5 17 18
ELECTRICITY NEEDS PUMING STTIONS Why is yor toy tri trnsformer cled 19 step-own trnsformer 0 oes stpp trnsormer do
In how mny wys c we use d ces? Cn yo nme some of the prts of d ce hy is it clled a dy ce Why is storage bttey cled a "atte d ot "cel ht are the two iquids sed i a storage bttery? Why does the store tter us distie wat
THE POLICEMN OF E HIGYS How does the overow vve i the aut moie protect it? Why is the fuse ofte caed the twet ourhour poice? CTIVITIES FO JUNIO EECTRICIN No. 1 o oes you shigh wo? No. ow cn a switch hep us No. How ca we coec coectt tw d ce to give us moe ower than one ce? No. How c we conect tw d ce to mae them ast oge No. 5. How cn we conne connect ct see see ig blbs in series No. 6. How c we coect seve ig bulbs in pre? o. 7. Ho ca we d out which jects re god conductors? No. 8. ow n we me quiz oad? No. 9. o ow w does a fuse protect us? No. 10 ow c we me n eect et? No. ow ca e me eectmg net stroger No. How c we ·me m e a eectrmg net stronge in aothe wy? o. Ho ca we me a teegrp set? No. 14. Ho ca we me eectic u ret detector
0 39
40
4 43
WE MUST OBSERVE SETY RULES Cn yo remember t est ve "never res
SUMMRY OF IMPORTN IDE
44
SOME IMORTNT TERM F YOU O REMEMBER
4
DY CELLS RE THE SFE WY Why shoul we never plce piece of met cross the to terls?
SOME FMOUS SCIENTISTS W MADE THE EECTRIC OSIBE
T HE T HE T N N
IS tory s not me up t is true t ell p p e n e M y town stoo stil for eigt ors? ?e e d o eectricit M ose o se ws ot te sme e bels i't rg rg M oter's wsing ce stoppe e Or televisio set ws rk siente lttle rio in room ws ust box witout voiceMoter voice Moter tre to se te teepone t e f t s s slet s rio Our eectric stove oine te wsig ce ro teepoe regerto e eectc eect c cc te itcen s stpe t :36 .. t's e ee ote cge te uses t s no cge n o ep O egr ce g g Why is the main elctrca cabl t fele of a modr idustial tow?
T T
elpNoting ws working in er ouse elpNoting iter Se ws re worrie er bb's formul neee refr ref rigertion e foo ws becoming spoie Se trie to cll te otor for er sick b ut er pone ws not worki working eter M moter drove er in te cr o pick up te octoren octoren se rrive t te gs stto to ll up te tnk se ws tod tt te pps were not worig Severl crs were tck in te mie of te ro No gs e ter te e c t worke t worked o te storge btter e ro r o s l o news news ce t e pwe stt estroe eploso eplosoeprs eprs re er bt it tke t est egt or o rss otorsts otorsts re rgd to gie e e e ee
o tt it e i eet cble been mge " Wy is tt tt cble cble o ipot ipott? t? ske my mote " t ble ble i like te i pipe upplying ply ing us it wte Mike my mote eple"en tt pipe i boke te wte tops unning ee i jut o ote wy of gettng wte An tee i no oter wy of getting eleticl poe ntill tt cble is epi nti epie e How ae we y te time D depedet upo me ome it eeicity ? e ep e im get ito te ouse by ligtWe ligtWe two nle in the n, nothe nothe in itchen, - one in the itche
lvng oom e our col inner by cnleg sser Susn e n
lot o u but Mote n in't tink t o nny e people on my teet lke bout wit ligt knocking on ec ote' oo ite of ingg oo bell veyoe w excite " Wen ill te gt gt go on? on? people ke " Soo Soon n oo oon n y D ep eplie lie t seeme tt long time pase befoe te ligts senly cme on e bu of te efrigerto stte st te My lttle io w o t fll volume e elevson set suenly ce to e wt pctue n son seeme s e sun suenl begn to sne in te me of te nigt y wn begn ve gin!
H HT T T H H
C T H HN NG
C C E ECTRICT?
E
E< TR E< RC C T, electia pwe, ust dent happen, pe n, sid sid d. d. " It hs hs t e made. ? t tigs e ued t mae it? ets see. "hen my gadathe· gadathe· gund his wheat, whe at, sid d, " he had had t tae it t a mill tht was ne a wateall. "hy nea a ateall? ased. "ell, "e ll, ie, ie, said said ad, " the theyy used used te waterall the pwe t un the mill. yu ave neve seen ne, dnt nw hw it s, we can uild a mdel. We eed a cheese x, a tic an axle ht, and sme ja cves lade. "hen wate alls n these cves ldes, the sht ges aund, and it, in tun, mves wheel and geas. ee, then, that the uel ued t tun these wheel is ee. The wate mve the ldes and the ill is in usiness. That te teic, ic, ad, t hw hw de de alling wate mae electicity? ased. I ht ys does a tera serve s?
IS IS DOLI DM WI IS U B POW FO OF FLL W OW M B DSIBD S PO O USD O MV O DIV MI MOV O FOW W I IVS D SMS BOMS SOU OF W W I S B OI BID DM USS DOW OW OF IS SOG FOW US O O UR
T mae el elec ec ticity which will t ly t a mill, t se t the electns thgh ds mde wie, shts hve t e tued isie a tel, clled a genet dyam. Wate ve te spplies the pwe t t the shts tht mae geete this gicl electicity. , , yes. We lered t sme these plces i schl Thee isHve isHve Wh re some o he wa ys we know o o mke electricity ?
D, Ni Nigr gr Flls lls,, th thee ds of the Tenn enness esseee Vl lle leyy A Atthor horiity, Gr Graand Coule uleee n nd d Bonn nneevil villle s s,, an and d many t t ers l lke ke th them em.. "
Ve Ve g, Mie, Mie, smile smile ad. " Ad pwe m these plces is set set hudeds miles t hmes, acties, s d schls. It eve s ailds d suwys. "Relly, d? te pe d ll tat? B Btt sppse tee tee e wtells ds eay?
DI KIS OF PO LS BU ll V SOMI I OMMO PO PL S G O LII IS MD IS S OLBUIG PO PL S D B OL I D SM MKS O MOV.
The ientit an enginee h thgt t that. The ha ge t wa t mae eetiit m the thing. Tae a a a eampe. That a hep mae tit e anhee. D nw t wa in man age itie n amae eetiity? That That ea magi magi!! ai m ite ite w ha een itening qiet a n N, an Jane Jane,, w wn ntt a t magi. I lie t a it iene a mae me ene. It an e eaine an ed eeyne, nt magiian De it w i iee te am? a Jane ae met meting ing lie lie it, Dad ntine ntine n the ae dam, wate ge int int pipe whee it t the lae te age whee. When a i e, tea ge int the ipe Te ae whee ae aed tine kd of por is usd to ru sub sub s? s?
" Is ths ths t t cnnected t a hing? ased. " Oh, s s t t t ti that maes the gneat sp and. Electcit cmes t th th a a ld pzzd. asd, as d, " hat s a geneat geneat? ? What d it d?Hw d?Hw des it w? " l l sh shw w , , sad sad ad " W a a a mdel a geeat Bt w sm thngs. san a, ths teattl. e, ng magnt and ashlgt. hav t the thngs we d. m ror pi rou
9
p py s xpr
usan Jane and an t get these thing, wndeing hw the ttle ws ging t e used. " Nw, then, sid sid ad when when we etuned, etune d, " watch and yu yu will see hw hw a geneat aes electiity. The e heat he wate in the ettle. That aes the stea, just as unig cal ca il wate t ae steam. t is this stea pwe tht pshes against the lades the tuine. y tuine is ade cadd, ut t gives y the idea. Then the tuine tuns the agnet inide a cl electical wie.
" s a manet manet ea eally lly sed? sed? I ased. I e s . t s a r ros agnet mde y pu electicii t, call electic called ed an electagnet. There are many many turns turns f cvere cvere wire wire wund arud arud an an irn cre. cre. As the gnet ov oves es inside inside a coil of wie, it pushe tiny things called tiny called electns. electns. Wen elecelectons t ons ae pu pushed shed o o moved moved , electic electicity ity fws.. That is why the light fws light that I eveed m ev m yu ashig ashight ht ges ges n. " Gsh , Dad, Dad , jut thi thin - a agnet agnet and an d a wie ake ou ou televis television ion sets sets
w! said.
RDBORD R BI
S
G
IN A GNRA GNRATOR TOR,, MECH ECHN NIC ICLL NR NRGY GY IS CH HNG NGED ED IO I O L LC CRIC RICAL AL GY GY.. I ADDII DIIO O O S S ,, FLING LING WTE WTER R ND ND TOM TOMIC IC EN ENE EGY A ARE RE OTH OT HE ELE EL E-
M TS TS H HA A MAY BE U D D O MOV OV N N A AOR. OR.
FLS O PO PO DO S L KD OF PO SO. SC S CD D CLLS. CLL "D CS CD PS SD CLL S SD P D CO C O SLL O.
"Rght Mke. But rememr t s ot ths toy mgnet nd not ths smll pece o we. It lrge electrognet turng nsde huge col o ire. It looks more lk tunnel. The ore re n the col th more electrons cn be moved. And e get more electcty.
O POL POL PO SO
" Do ou ou men men tat shight ad portale rado crry gnertor sde o them just for m very tme I wnt t use t? I ked, loog t my shght. " That That's 's rght. The bttery bttery s ts ow ower saton
y i porb por io
O ON
HH T H C E EE C CI Hw traforer el u ge elecrcy to our omes?
W
H T kind pumps e used to push these electos ll th wy m th power sttion t us? I wnted to o t t's 's g gdd wd wd pu pumps.' mps.' I ws coming to tt. yu know tt as we de long te highwys the e e eecticl igwys igt bove ou es tt we y eve ntce? me mes tey e even unde te ds. t e they o?'' o ?'' Sus Susnn Jne askd ey ey e e te gwys o wie wee
hose invisible electons re owing towd omes cties nd ms d sweed. s s te genet gene t kes te electicity it hs t be delveed wee it is needed. nsted t t ucks nd tns tt cy o goods rom ctoes we o cbles do te te jo hee. heehey . hey t uet tot n uss. H How ow do te wies do t?'' sed my sister ell, ell , ll ll ong te rods whee w hee the th e elec�ity is cied e pumping sttins clled trnsomes. Right now, all I will sy about the is that they hep te eectons ow long.
CC FO PO SO S CD O S O OS, C OS, SOS, S D COOLS. SFO P SPOO OF CC FO PO SO O ll S PCS. SFO S C SFOS O CS CC C FO O O VOL. C SO C C FO LO O VOL. X D SOS O P 9 LL F XP FCO OF A SFO
W is opp mos ommonl usd fo lri l ri ii
T he h e re re r cbe re me terl tht m e good cc r or crrer. ' lke hvg good cer ro thot bump a rck r t rvel over. Goo ccor are lly me of cpper. " I copper copper the the ly codct codctr r eectrcty? I e o. " There re other oe. Slver the best but t's too expeve o e Almum s lso good ccor d ginig der se bece t lgh pr f p ppr io of o f to to mllio e . We e. We e mll s." p rps." re re r r ll prp ke eletrc eletrc t m t mke do' u oppr irs in ou or
" Do we l ly y se copper? S Je te t ko " s D. " Tke r tter tter for exmple.he he curleup re e of it hppen to be poor coductor. " Wouldn't th me tht he electrcty tes to get through t hv tough job? I ske. pzze D siled. siled . " Wh Whtt hppe hppe a toster? The ires ge red hot. Th
shows us tht electrcty electrcty s havg h avg cult j ob psig psig thogh. thogh. B t m me
our tost tste good. eecric tve t brols our steks d chop cok or mels. Tht's ot ll. other's electric iron uses these poor codctors or crriers too. Otherwse the t bottom of the iron ol ot get hot eough t 1ron our hrt tblecloths a ther thng. ou " There re ma mayy ri is i other e for thee our om poor dtr. us poo oduos
a ome other ppce hh m hve them? Htg " ps. " Co Coe eee me mer. r. " W ee ro ro. . " A elect electrc rc he hete ter. r. " An elec electr trcc fry frygg p. " Th Tht' t' eogh, eogh, lghed lghed D. D. " let' k other to pt elecrcty t ork d prepre ome ome uch. Th tk bout ste chops makg e gry. e, " too eched, a y e to e tch
TRO ONS ELE ETR TION N OF FLOW OF EL IREC CTIO DIRE
CEL
CO ON OF B CONDUCO OF CC CUN, ND S D D NUFCU OF N CC , S E V CBS O S.
EE CTR TRIC ICT T I RALLY A FIR FIRT T COU CO U IN OF M AGN E T S Are magnets and elecricity relate?
"you
Dad, e f the thigs that you said yesterday still conuses e. What does the electrical agnet a gnet have to do with aking electricity? kow hat agets have some kid of power. They ca attract ails and ther ting ingss . Bu Butt how do ma magn gnets ets help he lp us mak akee elec lectri tricit city? y? " Whie I was talkig, Susa Jane was picking tngs up with my aget. " Magets ad ad electric electricity ity are i the the "We ined Da Dad. "We explined sae family, family, expl ight even say they are cousins We ca try soethg t t clear this up.
MAGETS HAVE A RAWIG RAWIG OR PULLIG POWER, D D ATRACT THIGS MAD OF STEEL, IRO AND CKE
THE WORD MAGNETISM COMS FOM NME MAGNESIA, N CIET C C TY TY OF AA, WHERE MY LODSONES WE FOUND. TE LODOE LSO SPELLE LODE TE A MAGNEC OCK ND WS USD NCT PEOPE N TE NG . A A ED, A PE OADE K T.
" Can we we help? help? be begg gged ed Susan ane. ane. "hy, sue. Mke, bg dow you scout copass. Susn e e bng the cove o you cayon box. hen we etued, ad h hd emoved the dy cell o my ashlght. " ut the the copass nto nto the the cover, cover, d stcted. "nd soe nslated e about eght o ten tes aond he cove.
Da touche o ed of o hro th r , hc r had trpped ac, t the botto of th dr c, ad tuched the othr ed to etr par t he top of t ce Dd ou ou ee wha whatt happd? happd? a add Da
S CS OSD DSCOVD ELCC D GS LD 1820, OSD O SVD S LCC CT OG S COPSS, COPSS EDL OVD. OVD . SOWD FLO OF LCC OG W CSS GS
ompasss ofMik's compas ndl ofM Ys, Ys " , the n
NETIS. NET IS. H HIS IS IM IMPORT PORTANT ANT WRK WRK RESULTED RESULTED IN
ns pen W hat h a p pe y cit y ectr ctrcit ele en el when wh
o at at r rht ht You o tat o agt ca o aothr agt he eectrcty t through th re, th eede, hch a agt, oed That eans that, soehere, there aother agethe agethe eectrcty o through re, ter aget aroud th re a a e ee ee t? t? aed ua Ja o " ot ot a ore tha e ca e agt pug al toe aet But the aget hre, a rght I ot ur ur I urt urta, a, I ad
AROUND ARO UND TH THE E WIRE. W IRE. M MCHAE CHAEL L FARA FARADAY DAY ALSO EXPE XPERIMEN RIMENTE TED D WITH ELECTRIC LECTRICT TY Y AND MAGTHE HE FRST ELECTR LECTRIC IC GENERA GENERATOR. TOR.
Y il , Mike. f a ma mve w trn tr il f ire, wul lctron mve e maget ae tr a il i zze a ieti everal re year , a ecied ecied to exeriet.Hi Hi experiment worke, a ta mare e egiing egiing of any wrl wrl i. f w e e a mall mall mat a a a mall ire ly a ew letr l mv. Bt e we move ver werfl w erfl ma iie toan toan f cil, may eetron w. w. It e' mattr r te mae r te coil mv, t i' te movment wic er i nra nra it r r larl larl , G. A y , r A maica ma icall ab it, it, ai Da. Bt le le a i. D y rer I tapi e en of the ir t ry ll t mae t ma mv ca o it eaier i we e a wi, v i De i make make any ier ierenc encee f andown switch or one tat we rin te doorell? aked Sa
What happens when a magnet moves inside a col of ire?
How s a sitch like a door?
Nt one it, anwered Dad E a c c on o n e a a mtin o an a n . We Wen n we e ay wic, te conecin i coete a e electrn ca ow agai. e e th wi e conc i r a t eletr el etr ann S Jane exclaime, at j ein r coin a ate r r. "Of ! Tat' a nice ay t u it, complimen complimented ted Dad. " D you ver ver ar te xrion, completig the cir' r reai t cirui' That' a i a. n e ich i e, lit, te rf, te wae ir, e mar, a yr eric tra, all en i , thee apliac .
TH MOVMNT OF A MAGT INS ID A
TOP: BREAKING TH CIRCUIT.
COIL OF WIR GNERATES LCTRICITY
BOTTOM: COMPLETING THE CIRCUIT.
O OMS OF SPPLD VOLS OF CC, B O CC S, FO XMP D F VOS O OP SP DO SFOMS SP DO, O D CS, VOLG OF LG , BLG A O RA O R. 50
5 R
_ 110 OL A
11 VOL A.
R O RA _
EE CTRIC TRICIIT N EE PU PIN G ST ST T I IN N
is ou o ti sfom spo fom
O the tra et yo ae me or my rthday ork ro y traformer? eer really ke hat that ord meat, d. Let Let look look t the dto dtoary, ary, geted a Jae Jae " A good good de de d d d. d. " Le Let t see. see. raform meas to chage n form.' "he e use a traformer or a tra, e plug t to the wall ocket. Our home uppled th olts of eectrty. Or tra e le erha eght to twele olt.How How a e t t dow? Doe the the transfo transformer rmer do do the o for u? I wted to ko. " es, t doe does.s. t steps t down, down, jut j ut a t de other art of the hoe. e have a trnformer to te do te votge beore t goes nto our doorbe.. e coud be coud use btte btteres, res, too, ut wed ve to epce them when they wee ued up. "hat does the nsde of a traforer ook ke? usn ne asked
I a keth t roughly for yo, ad Dad.. Ver Dad Veryy mly t ork lke th. here are two o of re, oe arer tha the other. rret et through the rt col, maetm rrod t. he eod ol aeted y the magetm ad eletrty ome ot of t wre " f the the eod eod ol ol larger tha the rt ol, more electrcty ome ot tha we to the orgal ol. f the eod col maller, a yor tra et le oltage ome ot. o e a a ay that the the traforme traformerr ed to rae or loer the oltae of thee rret. th rret. e a te te t or te t do "Rememer, whe we eak of rret, we mea A.. or alteatg curet. ry cell ad storage ttere are al D.. or dret rret. Are thee trasormers used ony " Are toy tras ad doorbel? qured ua ae. o. The Therr mot mortat mortat ue traortg eletrty from the power stato to ces ma mes wa.
FO OU PSOCK '
What does a ste step- p- up up
rformr do?
" W he " W hen n th bigg thee bi
geera tors mae geerators eletrt t s usuall at aot 2200 volts rssure. teu trasformers rase he resure aout 00 tmes to aroud 22000 vots. Ths hels t travel alog the wres etter. Whe t gets near the la where t s wated stepdown trasformers lower t t a to to 2,200 vo volts lts Befor Beforee t
SFO
reahes our home aother stepdown trasformer lowers t to volts. some homes 220 volts are " A ou see see these wode wodeul ul maes oerate as pumps to rease ressure or voltage. They also at as shrners of votage.
WE MUST OBERV AFY RLS
"
D
OU reeer hen I ha y ar _n a sling? Tha as very d bu I receive as a resul of areessness ih ecrc, Da o s Ho id i happen? san ane ane o kno "I ried o plug in elecri razor h y hans ere e, Da paie "I a prey uck o e alv
I as so aly ue ha he ocor ha o rea e for several eeks efor I coul use ha Can o eeb eeb e e a leas ve "neve les?
I you realy wnt to have fn with electricit," said Dad, yo r a to pla the mportant game o NV
NVR ouch a sch ih e or dap hans. Waer is a onucor ou igh e baly e or receive a sere shock When you touch a sitch or ny eleric appliance sure your hands are dr.
NVR oveloa our coecons Don r o p oo any eler appance no one hoe nce crcut t s dangerous ad can cae hort crcu or e 2
N put electricl wires under crpets nd rugs.
NR put a peny n the fuse box. Use the propersized use.
N pull the chi o a light ulb i you re stndng o a e oor.
N poke round the rdio or elevion elevi on e f he wh o
NEER touch n electrc pplance, tch, rao, or teon whe athng or when we
NEVER remn uner or ner tree urng n electrc torm or n ertorm Lghtnng my tr
NV rma a ae r
thnderstor.
EVER bt ever toch a roke cable ater or drig a storm or at ay time Call a policea or rema
NEVER place anything except a plg into a wal socket " em emembe ember r cotin cotined ed Dad Dad as we lsened very crefuly " electrc electrciy iy cn cn e your riend or yor enemy o canot arge with it It will ot orgive yor mistakes It will ot accept yor apology It will reward yo or pish yo It does not pay avorites Treat it wih respect ad understnd understn dig ad i will serve yo loyally
DR CLL R H HE E A Y
D
AD over to us and placed hs hands on our shoulders. shoulders . " "ell, ell, ou follow these EVER rules, ou wll be dong the rght thng.You thng.You can tll have lots of fun wth electrct f ou work wth dr cells. The cost lttle and ou can carr them wth ou.You You a put tem n a o and take them to school, to the plagroud, to our frend's home or porch, and perform experrments. You expe You can can have aa grad
tme. The are useful and safe. W hy should w e neve verr
pe pee of m ro e to ermi?
" Ar there any
EVER rules for dr cels? I asked. nl " o, ad
Da d . "N Dad "NE EVE VER R put a pie piece ce of me meta tall acro cross ss the the t term ermin inls ls.. If yu do do,, ou will cause a short short crcu crcut nd bu out the dry cel ell.l. Tak akee car aree of th these ese l ltte tte pow ower er
statons. ad opened my ashlght and rmoved the small dr cells.He He gve one to my sster and one to me.
I o m e u dr e?
" Th Ths s ne ne nve nveton s ver useful to man people. hat a help t s
for those who have for have to to walk n plac pla ces whe here re ligh lightin tingg a m atch atch or or ca cand ndle le wou ould ld
be dangerous! "hen the farmer has to attend to hss lvestock h lvestock n the a, a m atch or
candle could be ver dagerous.'' " at at''s rg rght, ht, sad Susan J Susan Jaane. " One slp and the the whoe barn barn could could be set o o
re. "hat about the coal mer who as to go pokng around n the dark? I suggested " Ther Theree are gases gases there there that could caue an eploson f he t a matc. You " are both rg rght ht sad Dad. " Ad don't forget how octor oss uses s ashlght to loo at our throats. He carres t n hs pocket lke a fountan pen. The dr cell s used now more than ever before. How " does d cell work? sked.
" f ou were to oo oo e oe o o would see chemclhey hey re red to ue etl tl d ec ece et tl l to work u seve you when you pres a button or p wtch There re o ecret word to y to m t work Ayoe cn lern how to do t t's esy d t's fu I fct you c tech t to or fried
W OR ASPHALT
CENER OR PLS RMIL
ou ae some o he pas o d cel? GRAPHE
+ MAGAESE DOXID
+
" Jt a a maet h to oe orth a ou a r e a two o l ad mu D e the ter o hat mae o ao u dhe dhe ae roud he e ual mae o a mtl ald a m
Wh is t caled a d cel? CARBO RD
a acw ut a dr ell do ete o e are om t the chemcal a ta mafatre the eecta erg ometme a eetro mae t a har ate o th t c arre at at oe o the eao ar ad el
Wh s a soage bae called a "ae ad no a "ell? POOUS CRDBORD
DRM OF DRY
CEL
e e or or a a e a o or dr cel as a attr attr a r awere Dad he car ae a tore aer t doe o u a ar at e or ahlght ahlght el e ma a a w ater "A a ua Jae he
+ COCG SP
D SP O OC US D LUS
-POS
CELS INING CELS S O F DJ INING NALS TERMNAL TERM
S O S PLS D SOS C LL
PUS (POS) L CS DDD O 3 COPS O CLS Y GE BER BERY STOR RGE GAM M OF A STO DIAGA DIA
ha ae he o lqds used in a st or age b at t te r y y ?
"Rgh I ses dslled aer d a n aci d
_
a very
agers acd " D ea ea ha r ar ar ar als kes elecr le checa la? I asked " A chemcl pla s correc, sled Dd. " The sorg sorgee baer baeryy r car s a rel e an I ars r r d hels t r. I mkes r lgh g . I wpe the wdos a rasr It rn r heer n he er. I ges or rad power. M cgree lgher uses he bttery. Eve he ds ope nd close n m new cr, ha he te. "h do we use dslled aer? ceaner? I wnted o kw. "hy do we need cd, s s dneros? sked s Je
UBB SRO
h does he soage bae se dslled wae?
MUS (G) PL
" t tlled lled a lke ra ae des h a re, sa
Dd. " A d he cd cd cm cmes h he led o o gve s el elecrcy ecrcy The car s se e he ba baer sp sp rk he gs gsole oo oorr o ge sar sared. ed. W Who ho e e
car wld' e Dad oed r ce r hs car c ar.. He rased rase d he hd a a e peered peer ed n see he aer aer " The sr sr ge baery n he cr s sae toch s he dr cell or ashlg, Mke The acd ca cse a seere ad ake hles r clhg " Do remem rememer er he E EV V game? Dad asked "e sre d, asweed sser " Gd E EVE VER R ch a a ar h ar he e r s her her lked lked ver s " ld j ur scens scensss lke cl h; chmcl r elecrc r gs leoered che nd ke rde wh me? I'l need se he h h groceres she s.
T H P OI CE M N F H H HIG HIGHY HY S DO P OO (OP)
DG ADA O OP OO A, OG X M P. NDD OD O EE P
How does the veow valv in he uomobil proec i?
HR were n car o he roa o h erare, an a olcean wa on u drecg rac. Eery so oen he would so he car ro ov ni he ra ahea cleare u. h can' he e u go hrough? I ae. he ocer loong o or or aey, oher exlan. He le a aey valve, a Da, ju a we hae sae ve n loco oe an n he raaor o h car. hee valve are eldo use bu he are er poran. hey ar he polce en o hee chnes. en he loco oe ha wored up oo ch sea an n anger o expodn, he saey vle release he exra sea. he ae hng haens the raaor o he car. he olcean sgnale o go ahea.
W h u oe lled h ey-fou-ho poliea?
t t liceman o tc o a ha th ca ot crash no ne noher, o a e or hme sops elecron fro ovng. r en oo an ie lugged no one outet, th eto lke e cars, begn crasg ito ac e. hen ha haen, th ta emn maes he ie a. The es ay get o hot hat the a o e ouse coul cach r. The fue so thee lecto jt as he begn o ge ho. St' ay th polcemn. Blw,' a th fe. h s go ou. h toaer to ot d e brle sop broil."
FUSE S EECTRC SFETY DEC. E TOO UC ECTRC CURRET FOW IEC OF T N TE FUSE ETS. TtS REKS TE CRCUT. WTOUT FUSE TO REK TE CRCUT ERY STROG CURRET COUD CUSE FR
To any ti a ere on a on . The ove e crcu. a as one o he NV rule, I ai. Vry goo ie. Y qucly. It a goo th t fuse as here. member tat t t use box our oceman. It i our home and or lve. I'l o o hw to mae a t on" In ac, I'll re down the directo for oher acvie ch yo ca do t lea a l more abot electt." Here are he actvte hat Sa Jane's and Me's Dad suggesed. o can ry hem, too.
ATIVITS FO JUNIO TNS
T
ee ace D y f yu ae ucceul a . Fllw e dec ad aa a carefully a yu ca. u ill ae a rea deal f fun.
O
Remember Wen yu ee he rd
ie" eans nulaed we. Wen ay, cnne we," i mea a e ed f e re are e pped iulain, maeral r pain.
O O E S O U R F L S H L I G H T O R K ?
u will use
Flal Pece f e
I L
tis
Tu yur al n and en . N a yu ae ue e al rks, ake apar ee e deren p. Sip e sulai f bh ends f a ece f e abu ix nce ln. nd e aru arund ed f f e ba e w e ap e e ed Wr ap eved yu u r eved a y e bulb a bae e f e e ba
f e al. uch e b f e bulb e cner eial f e cell. bottire to the bo d f t e w ire the en end uc c the Tu
of he cell. he lg e . Why t wks
en u cled e wc f e l, yu cmpleed a ccu. a , yu pded a cld pah for curen fll i ccle
PIN O OLD BIS OR D MK OCT
NO. 2 .
HO W
CAN A
S W I T C H H E LP
Yu will ue Dry cel (lare or sma) Flashligh ulb Miniaure socke Wir Piece of meal ck of wood Block Blo Two ails Hamme D tis: Do you remem Activity N 1? We were able o u he ligh on b ouching he ire e cel. Then we removed he wie an h ligh wen out ha's pr ey ey simle Bu n esie way s o use a swich Take a piec piecee of meal ou inc inc he he lo ad one ich wide (You can cut i fom a in ca i you are caeul) Nail one end of i on he block o ood Place aohe nail in he wood unde he oher ed o he meal Do no place eiher nail all h a don in he wood Be sue ha e loose end o h ea s o e o e ail eah. ou hae a swich. Now y ou Connec oe wire fro eihe minal of of he d cell he nai une th meal. Remember o srip o the insulaio e we you use onnec a second wie from he ohe temina of he dry cell o eihe emial of he miniatue socet al onnec a hrd wire from he ohe terminal of of he socket o he nail hold
U S ?
ing he srip of of meal in place ow press he swich If you have me all he connecion properly, he circui is closed and h ight i go on Save his swich You will ue i may imes in hese aciviies. Wh it works: I you have a lage a lage dy cell, you wil noice wo erminls a he op ConC onnecing wires o he is done much ily han wih he small ash more eas ily igh cel Bu l of these civiies can be done wih eiher cell, excep hat he larg ll lass loner and i is easier o use cell ce Each cell gives us l vols onnec he wires he way you did i Activity . 1. The swich is convenien way fo us o open and close a circui I i asier han connecing and disconnecing wires I is also a saer way o tu he lighs and oher elecrica ppice o n o
DRY CEL
31
O 3
H O C E C O E C C O R C E L L S
O G G V E U S M O R E P O E R H O E C E L L ?
u wll ue
To dry cel Wire Sitch shgh bb Mure oce ti:
Do yo remember ho bright he bub s in Actvit N ? No let's see h hppens hen e ad anohr dy ce o he cici. Of corse, it h o e conneced propery. onnec one re been he cen ermn of ce 1 n h end terminal of cell 2 . The reminder of o f he connections connections similr o he y yo id them th peious ciiy. Oe e s s c c �cted bt bteeen te em em l l o c o cell ell 1 ad a soket a sok et t er minal d d sec secon ond d ie co cone nes s te te oh e e sck s cket et e en n to to ete ete ni on te ,
stc Te lst ie conects te oe nil it cel 2's cente te in. Press he sch. See ho uch brghe he lght blb is?
it wr:
DRY
he o dry ces connecte ere resuled in bo tice the o f ne cel. hs mde he bub brighe. hen you conneced o cells f � ols ch n seres, yo relly adde hem. Ho mny vos do you v no ou you ke o try t a elc rc be?
NO. 4.
HOW HO W CAN WE CON CONNEC NECT T TWO DRY CEL CELS S
TO MAKE HEM LAT LONGER?
u wi ue:
Two dry cells Wre Switch lashligt bulb inature socet
o this: oct the dr cells wires switc ho i th iltrto. irt coect oe ry cl ct ith o sitch th iht b. H hve oott ho t o o to ctivit No oct to ot t th nl o l T th wire r t cente tr c t it to the t t
Tae the wire coing ro the e terinal o cell 2 and connect it to th end terinal o cell 1 You sould ow have two wies connected to each o te terinas o cell 1 ress the switch. Notice hat the light i not brighte tha it was when onl o cel was in the circuit. it wr:
You connected the two dry cells arallel. No, the ligt is not brighter tha it was wit one dry cell. at is why arallel connections are beer wen cells are to be ue ove lo eriod o ti. 33
O. 5.
G H HT I G
HO W
CA WE
C O N E C T S E V E R A L
E R E S ? S E B U L B S N S
u wi use
D ce We wtc wo at u wo mnatue ocet tis
Conect one we fom one tena o you d ce to oe emna o t wtc No connect a econ we fom te ote tena o te y ce to one tena of ocket 1 Conect a td we etween te eanng tenal o ocet 1 t ne tenal o socket 2. No connect a out we etween te eang tena o socket 2 to te last tenal o te wtc Close te stc Te bul oud lgt Eac u not a gt a t wen e ued oe n ou ccut No unsce one bub Te ote ul wl go out Wy it ws
Wen bot uls wee t electcty was wg n a coplete pat toug e ow outt of e t It was It was abe abe to ow ou the ccu ccut
dy cell t tou te bulb and etn et n to te te dy cel cel ke a meo meo ond Ts s called connectn bub n see In Activity 2 we used on d cell ang 1 V vot to gt on u Te tle bul was bgt
Now we d Now dvdd vdd ta 1 V o teen two bulb bulb n e ere re Eac Eac
eceved ony % o a vot Do you ee why te bul n ee wee a bt dm? Wen you unscewe one u, e ote one went out Do yo kow w? Becau you nteupted te ccu Te eecton we no owng n a eygoound O yes dd you now tat te tn e n te tte bulb ou eoved wa at o te pat tou c te eecton ow? Ou ome, stoes and oce ae a edd n pallel e p allel tey we conec conected ted sees, a o te g woud e on and appances unng a oe m o not at a Wng pa oe pacca
O 6
H O C E C O E C S EVE R
L I G H B U L B S I P R E ? You wll use:
Dy cell ie Switc Two sligt uls Two initue sockets Do ths:
Connect you dy ell switc nd one socket in coplete cicuit Pess te switc See ow it it i? Ty to eee ow it looks Now we e going to ing aote ul into ou cicuit ctivityy No. 5 we connected te In ctivit . m sees. Do you eee te disdvantae o tt cicuit? Connect a e eteen one ten o socket 1 ledy in te cicuit t one teinl o socket 2 Now connect note ie etween te ote teinls o sockets 1 and 2 Notice tt tee e two wies co
ing out o ec teinl o socket 1 ess te switc Bot uls sd lit Ae you supised to nd tt ea ul is just s igt s te single ul you lit at te stt o tis activity Now unsew one ul e te one emains lit Moe supises! Why t works:
ou ave connected two uls i pllel c ul s its own pt to ad o te dy cell Te pt does not ve to go toug ot uls s it did in a seies cicuit Ty tcing te pat of te ee cent t ec b Since ec ul is connected diet to te dy cell ec is s igt s i yo d only one bulb Now i one ul goes out te ote eins it s in you own ouse 3
. 7 .
CA
FI
U HI H I CH CH B J C
AR G C U C R R?
ou wl use:
r cll Wi lahlht blb iiatur oct o thi
oct ir t on tria o a d cll ad trial o a iht oct. ttch o d o noth to th othr r cll tril. ttach a thid i to th oth t mial o th oct. Th nd o th to ir hold b r. Toch th to r d o th toth bri. Yo hav o coltd th icit ad th iht h o o.
AL
Tou ouch ch t he he two re re nd nd s f th e wi e e s
to opp ot ot d d of a a io ail. Th
iht i o o. Tt oth at rial Tt rial i th i i ma ar r to s s w ic ic o os s he l l the g o o. h it wos
ti o hv d 1 to cot o cicit. W sa ho a ai ct i th m . o m mta ar ood condctor o lctricit. Som ar btt t th. I o tt l ood or rbbr, ou ill d that t liht ill no o o. Not oh lctrcity ass throh thm to liht th blb. h tial a called ocoductors.
NO. 8.
HOW CAN WE M AKE A Q U I Z
You will use: Dry c Wir Fhiht bb Minitr ockt Crdbord i Do this: U th ni to nch i ow th lf id of ic of crbd nd ix ho don th riht i Pc th end of on wir i n ho t th ft nd th oth d h at th right Strip th intion fro th n o th w nd cr it in c Rt thi with v oth wi Yo no hv i wir in c i hhazrd w. St thi i for whi ell tw een een a dy c ell ir e be tw c t a w ir Conne c na. eri na. socket cket t eri rminal and a so te rminal mainto te e maine wire to Connec t anoth e
ell. rmi nal nal of th e dr y c ell. ing te ing te rmi
BOARD ?
No attch third wir to th n trin of th oct maini n T i imir to or conducto tt i Activity No. 7. Toch th t wo wo f of th i togthr bri Th light wi o o Hold h cardbord o tht yo c no se ho th wir r connct Plac th n of b i i v t t ft i wic w i qtion, nd th of hi t o th riht id� which wil b th w B r tht th t on opoit nd of th am wi Ak yo frin to tk t two c nd of th i fro t ockt. ow t to tch th tc q tion tion d w Why it works: By touc ng ng the q que ue stio stio w ith ith n e nd of th e w ire, ire, an an the the a sw sw er er wit t
othe r n nd d of the wire, wire, the light will go o T cu t ccut bn c ct t
DRY C E L
O 9
HO OES FUS E PROTE CT US ?
You wll use
Dry cell re lli ul n ck oil lck woo w umck Do ths:
u a piec of n ol o e ener n s pce of wre Secure o lock f woo w wo thumbck Do no pus e ck ll the way own Se s e for wle Srip abou wo nces of nulaion awy fom ml oron of wo wre Connec wre o e wo ermnls o mnure cke onnc o en o oe of ee wir o ry cll mnl Connec or en of he econ wire o on o umacks of your fu oar e r e trpp en of e w n coc w e metl of e a Connec ir wre bewen e remining ry cell ermial an te remining umack e l oul go on Lay a re we r ny ece of mel acre acr e wo r wrs Te gh w o ot you ee ow he tnfol e mele nrrow r? hy woks
l wn o ecuse e crc w cmple Elecrcy owe 8
l , s s n our ome n you plc a pece of eta cros e w r wr, yo cue a or ccu Elcrcy s ble to w ck o y cll w w ou ou pan ul o lgh t lccy w no ue by e ul cu wr o bcom l p ml lwr mp n or wres he p, ccu w broke lccy we pocs u y ung ot If fue were not ere, the wre woul e come or n hote i coul he reu a re
DRY
1
. 1 0
H W CA W MAK A
ou will use:
ry cell Swtch Large nal Small nals r aer cls o ts
nd abut en turns f wre arund a large nal. St te nsulan frm te ends f te w. Cnnec e end f te wre t ne ermnal f a dr cell and te er end t e termnal f e stc Preare a secnd wre Cnnect ts wre e ter ermnal ermnal f te dr cell and e er end e sc Nw clse te swtc and r ck u aer cls r smal nals wh te large nal Open e swtch and e mall nals r e paer clps a dn
L C MA MA ?
Wy t works
e elecrct frm e art f te dry cell ws tugh e any tus f wre back nt he dr cell e electrcty ws rug a wre te wre as agnec e arund t. If the wre haens t be n te for f a cl te magnetsm s een strnge. Nw when we ut an rn nal nsde te cl te nal becmes magnet. s s true nl fr as lng as the elec trcty s wng n te crcut. It a magnet wen u want t t be u see hw manets and elec trc are related ur magnet reall depends n te eecc ges m e d cell. e nd electrmagnes all aund us. e nd em n refrgeratrs n ele sn sets eleones n Dads elecrc saer and n es acuum ceaner 9
NO. 1 1
OMAG N E T C TR TRO LEC HOW CA N WE MAKE A N ELE
R RO ER?
You wll use:
r cl ir e W ir
itc Larg nail Small nail o thi:
Conct our lctromagnt in th sam a that you did in Actvty No. 1 0 - cept or on thing. hi tim ind went-fve turn o ir around th larg nail. Clos th itch. itch. S ho may mall nail ou can pick up Do this to mor tim Do ou kno ho to nd th avrag mbr o nail pickd up? dd th numbr o nal pickd up in tre tri. Thn divid by thr. hi ill giv ou th avrag nub o nail pickd up b th lctromagnt it t tntv turn o 1. Writ th averag don. No that ou ar an prt rap
ound ns of wir ar ound enty -v -v mor e tur ns tw enty r. toth thr. rns all all to turns makig kig t y tu nail, ma th nail, umbe mberr of nail you ca Cout Cou t th e u o more is i me. me. Do is t o ck u is pi ck
ime. Fid the avrage nubr o nail ith magnet net w ith our elecro elecromag picked up by our
y us o ire. rie i on. You u ll ll ages . Yo h o o aver ages Compare h Compare nails wer picked up by e hat more na s e ns. tur ns. ith mo mor tur agnet w ith he elecrom elecroma
Wy t works: Th e mor e t us us of of w ire ire y ou have ou have,, th e mor e ma magn gneism eism ere s aro aroun und d th e coil, an coil, and d th str th str oger oger th e elect elect r r omag omag net. net. You ma ma h av fo av found und th th at at y o pi o pic c kd kd up about about t wice wice as many many nails w n n yo you u
doubld e number o tu.
NO.. 1 2 . NO
HOW AN WE MA MAKE KE AN EL ELE E T ROM OMA A NE NET T TR TRO O ER I ANOTH OTHE ER AY AY ?
o will e
To r ll i it L nil ll nil o thi
o o eb ho to onnt to r ll i to giv o ltity? Yo t b to onnt on b th l o nt trinl o on r cll to th n o n tinl o th ot ll onnt on i ro th oth tinl o on ll to on tinl o th it tntv t o i on lg nil Ce e e e elermage t te ee termal th cell ad te er t the witch Cle te wt d ee hw an al u a pk up ry t tre tme t a average umbe Hw de it cpare wh t um be pke up evuly? y it works:
hn · connct to y ll in re, w g twce a uch lctrcty thn w do wth one cll Tht i, get ntad o 1 � vl ro on cll hen w can b ur tht i w wt trogr maget, we u ed mr lctrcity throh th col 41
O 1 3
HO C E MKE TEL EG RPH SET ?
u wll use
Dy cll W wtc al ece o meta loc wd ts
Ben te pece etal nt e Zape n n te daga Nal t n te lck wd ae t nal nt te wd tat te ae ut ude te ee end te etal tp Cnect a aly lng lengt we t ne enal a d cell Wnd te e eveal te aund ne e al benng at te tp an wkng n Ten bng te we ac t te te nal a n t aun a an te a te te e wkg upad nnect te te end t we
DRY CEL
t ne tenal yu wtc Cnnect a econd we etween te ee tenal te dy cell and te wtc Cle te wtc Te unde te Zaped etalwl e attacted t te tw nal undeneat t u ay ave t adut te unde bee t wll wk u ave nw ade a ple telegap unde and un gap undd a pactcal ue yu electragnet Wy t wrs
Electcy wn tug te col we aund te nal ade te nal agetc Te unde wa attacte t nal a lg a elecct wa w tug te ccut Te au Aeca Aeca nve auel F B Me n 1844, a t ple t cuncate wt peple n dtant place y gnal tu an o te telegap
4 C E M K E E E C I C CU RRET ETEC ? u i use
el Lon wie Mneti pss Blok of wood Cove f sll dbod ox Four tubs wo ppe lis D this:
W bout ten tuns of insulted wie ound te ove of a ox. Stip te insultion fo te ends of te wie. Pl te box on blo of wood and seue i in plae wit some tu s. Bend two ppe ips i f, as sown. Wp te ends of te wies ond e tubtks. Slip the ppe lips nde e ks efoe pessin tem into te wood. e ppe ip will be ou leds. Ple yu mneti opss inside te box. Connet wie between dy ll eminal nd swth temina. Connet tw ote wies fo e ell nd switc to te ppe lip leds. Close te sit. e opss needle will ve. Open nd lose te swit seveal times. Why it wrks
o ou eebe t wen ele tiit oves tug il mgnetis is ll ound t? Tt gnetis goes igt toug te glss to te neti eedle nd moves i.
DRY CEL
Some o he imporan ideas esened in his book are smmaize belo. s yo ead hem yo may an o go back and eresh yor memor memor..
TON OF O OF LTON
1 lecriciy is made p o mov
4 More han on cell conece
ig elecron.
2 . lecriciy ms have a com
in eries will give more oe ha single cell.
5.
plee circi i i is o be sed.
Mor e t ha ha one ce cell ll c on neee ed d
i pa paaallel w ill ill g iv iv e lon long g e e i f f t han han s ing ingee c ell.
swich i sed o ope ad
close circis. 44
6.
Ligh t ts i n ou ourr ho hom mes e w i i ed ed
in parallel
7 . Some material, aticla metal, carry electricity ett ta othe. The ateil re calle goo cocto.
8. hort cicit occ h th crrent can o thoh ea hort ct intea o oig throgh the rla cicit.
10. lectrcity ong thog
col o ir aron a io coe mae the core ito a magt o a long a electicit i o ing. Thi an electomagt.
11 The rength o an electromag-
net can e ncreae by increa ng the nmer of col t.
9 . se proec rom amage
de hort crct, or rom ng oo mch electricity at e sme me
1. The trengh o an elctomag-
net can alo e inca dn d ce to t circ 45
O F OR
I P O R N R OU
O R E R
n re n c cur c ur re tric ectri n :: An e lec c c ge d at ange chan ow is ch ion o f ow e c c ion whoe dr e ims p er y t ims ny (mn v v (m i ddic i
)
Ammer: A me fr measrng e reg a elecrc crrn e rat e the sur s th masur A unit that ma ren t. cur r rent. electic cu ow o electic o f ow
Cu rr : A uc ch wch break e crc en o mch eecrc s g s smar a fs, ca e reud. mpund : A sbsac sbsac frmed frmed by a cmbnan eemns. ndcr : A gd cae caerr o eleccy acs as a hghay Drec crre crre : An ecrc ecrc crr ha s y e dc dc rgh a crc
Am : he es es p r f an eemen Dry c : A s ff-co -con naai d vol olt t aic aic ce cell ll w o o lc c oly oly i mois ois p s s e p k k ig ig y y r ru u r b . .
ecre: A sun gh hc eecc ca
r mr ecrca cels ccd geer Cru: E ph g c eecrc a w fm he srce hg es d pacs ad ack he srce 46
Eecrma Eecr magn gn : A e ud ard a c es a mag as g as crc s gh he c
: A e e us re re e slst slst . . l : A susne d up f nly nly e f .
u : A d s plen us dn. e fuse n es . s r e crcuit.
Ohm hmme mer: r: An ins nsum umn n tha tha mea ea--
surs lctr surs lc tr l l r sst sst c c . Pr : e re f d . .
Gr : An sruen fr de uns f ey. fr: A e n es r drse f n e u. V : A ut ut urs urs el prssur. Genrr: A c r dyn t prdus ly f cil ry. Hper: A uni fr esuring per. nsur: A y pr cnducr f ciy. K : u s. s. Mcul : e e prt prt c pud. augge um nt to gau uniit o m au A un l aage of l tee p a t an to t it ei t h h nt nt . t r r c c
V: A ee esung e. : A u r surg ll r.
OM
F M O U WHO
I E N I S
M D E
RI lessn V ( 1 7 4 5 - 1 8 2 7 ) , tly, mde e s cel t puced an elecic cuen e pe ( 1 7 7 5 1 8 3 6 ) , Fnce, eelpe e science o elec trgneis Geg Sin O ( 1 7 8 - 1 5 5 4 , Ger ny, ed i cue eeciciy ice F ( 1 7 9 1 - 1 8 6 7 ) , ng ln, e e st elecric geneatr Jmes ( 1 7 6 1 8 1 ) , Scan, inene e sem engine Smuel F. rse 1 7 9 1 - 1 8 7 2 ) , Unied Ses, inened te telegaph. lexne Gm ell 1 847-19 7-1922 , Unied Ses, inened e elepone
GE GE
HE P O IB LE
Gugielm acni ( 1 74 74 1 7 ) , Italy, st send a essage oer radio ave. ugi Glni ( 1737 17 , Ital iscee a eectici is pssible by cemical acion. ms la isn 1 87- , Unie Stes, inented te electric ligt bulb Hns Cisian Oersed ( 1 7 7 1 8 5 1 , De, und at eecicit and mgnetism e related Cles Prteus Steinmetz 1 1 9 2 ) , United Stes, me many con ibuins in te eld o electrica engeen
·
HOW AD W Y N ER B K S
se ook ookss es, t the hese titi ities, a t n oted a ovedd b y noted a pprove ced an d appr Pro duced Produ ce, , n n-t sciece scie e abot abo ften ae a most mo st estions ons tee q qesti answer ans wer t dle le red cleer, re sented ted n a cl preesen The e are pr hor or.. Th e ad h tue tu lsls ctve ve d i nstruct nstru rf and an n crf c ain n man ma nd contai cont stye, sty e, a ese these e ach o f th exp pe a t ex a a es ns R a ra rans lumes es s ese o olum lect th these colect jectss a nd co suject scntn tngg su fascn fa libr r.. sic ic lib ce bs eferen rence ady-r y-refe ic, e ead thet etic, uth u 5001 5002 5003 5004 500 5007 5008 5009 5010 501 5012 503 5014 5015 5016 5017 5018 5020 502 502 502 502 5025 5026 5027 5028 5029 5030 5031 503 5033 504
5035 DINOSAURS 5036 WEATHER 503 ELECTRICITY 503 ROCKS AND MINERALS ROCKETS AND MISSILES 5040 INSECS REPTIES AND AMPBIANS 501 502 BIRDS OUR EARTH 5043 BEGINNING SCIENCE 5045 MACINES TH HUMAN BODY 506 SEA SELLS 5 0 47 ATOMIC ENERGY 5049 504 9 TE MICSCOE 5050 THE CIVIL AR 505 MATHEMAICS 5 0 53 BALLE 5054 CHEMIS 055 5 05 6 ORSES EXPLORATIONS 5057 DISCOVERIES 5 05 8 PIMITVE MA 059 NORTH AMERIA 50 60 PLANES AND 061 INERPLANARY TRAVEL 5 06 2 ILD ANIS 5 06 3 SOUND 506 4 LOS II 5 06 5 AS AND EES ID FLORS 50 OGS 506 PREHISORI MAMMALS 50 SCIENCE EXPERIMENTS 5069
ORLD AR II LORENCE NIGTINGALE BERFLIES AN MOHS ROBOTS AN ELECTRONIC BRAINS LIGT AND OLOR WINNING O HE ES THE AMERICA REVLUION CAVES TO SSCRAS TIME MAGNETS AND MAGIS GUNS MOUS SCIENISTS OLD TESTAMENT BILDING TREES OCEANOGRAPHY NORTH AMERIA INDIANS MUSHROOMS, FERNS AN MOSSES THE POLAR REGIONS COINS AND CURRNC BASIC IVENIOS HE IRST ORLD AR ELECTRONICS DESERS AIR AND ATER SAR AIRPLANES AND TE STORY O FLIGHT FIS BOATS AD SHIPS TE MOON TRAINS AND RAILROADS
WONDER BOOKS nc.. lap, p, I nc unla o f G ross et & D un isi on on o ivisi A D iv rk , . 10 0 1 York Ne w Yo