,?is file 0 produc$ f page images at ! ,int]net ,ar*ive4 ,transcrib]'s ,note ,?is book 0 transcrib$ f scans ( ! orig9al f\nd at ! ,int]net ,ar*ive4 ,! page scans 7 done by ,google4 ,! orig9al book 0 done z ?ree volumes1 b ! edition ,i h transcrib$ put all ?ree volumes toge!r z a clo?b\nd book4 ,z a result x _h ?ree id5tical prefaces & duplicat$ ads4 ,i h includ$ "o preface1 at ! beg9n+1 & put ! ads at ! end ( ! book4 ,i h rotat$ a c\ple ( illu/rations4 ,arts & ,sci5ce ,s]ies ,no4 #g ,home-made ,electrical ,app>atus ,a ,practical ,h&book = ,amateur ,exp]im5t]s ,9 ,?ree ,p>ts 99,volume ,i99 ,second ,edition 99,,by99 99,a4 ,m4 ,p[ell99 ,,publi%$ ,,by ,,cole ,,morgan1 ,inc4 ,publi%]s ( ! ,arts & ,sci5ce ,s]ies ,p4,o4 ,,box #dgc ,,city ,,hall ,,/ation ,,new ,,york1 ,n4 ,y4 ,pr9t$ 9 ,u4 ,s4 ,a4 ,copyright #aiah by ,,cole ,,morgan1 ,inc4 ,,preface ,! purpose ( ?is book is to aid ! "y exp]im5t] 9 build+ & op]at+ 8 own electrical app>atus & in/rum5ts4 ,e boy ( n[-a-days exp]im5ts ) electricity & ! "r sort ( book :i* furni%es him ) ideas gets close to 8 he>t4 ,( books ^u electricity !re is no end4 ,t is grant$4 ,b !re are v few practical books = ! "y exp]im5t] :o wi%es to con/ruct miscellane\s electrical app>atus = 8 own amusem5t & in/ruction :i* really am\nts to some?+ & :i* is wor? 8 pa9s :5 ! labor has be5 f9i%$4 ,?is book is !re=e (f]$ z a volume ( in/ruction = mak+ all sorts ( batt]ies1 rectifi]s1 motors1 etc41 :i* are entirely out ( ! toy class & yet are n s elaborate t !y _c be easily con/ruct$ at home by ! av]age boy :o is will+ to put a little c>e into 8 "w4 ,! mat]ials requir$ are su* t !y c he procur$ )\t any great exp5se4 ,x has be5 plann$ to pres5t ! mat]ial 9 su* a mann] t x w aid ! judgm5t ( ! "y exp]im5t] & assi/ him 9 develop+ 8 own ideas4 ,)\t exception1 all ( ! app>atus describ$ 9 ! foll[+ pages has be5 actually con/ruct$ by ! au?or1 n only once b _m times & put to a practical te/ be=e be+ embodi$ into ! book4 ,y may !re=e be sure t if y foll[ ! in/ructions c>efully1 t ! result w 9 ea* case be a sub/antial piece ( app>atus :i* is capable ( fulfill+ all ( y\r expectations4 ,! draw+s h all be5 reproduc$ on a l>ge scale & 9 almo/ e case ! dim5sions ( ev5 ! smalle/ details h be5 giv54 ,"s ( ! app>atus has be5 describ$ 9 ! pages ( ! ,boys' ,magaz9e & s9ce its publication ! read]s ( t magaz9e h writt5 to ! au?or ask+ que/ions ab\t ! app>atus :i* h enabl$ him :5 rewrit+ ! mat]ial = publication 9 book =m to cle> up _m que/ions & fur!r expla9 9 a little m detail _m ( ! problems :i* naturally occur to ! boy :o likes to build 8 own electrical devices4 ,,! ,,au?or4 ,,preface 4444444444444444444444444444444444444444 4444444444444444444 ,,*apt] ,i4 ,,/atic ,,electrical ,,app>atus 4444444444444444444444444444 ,h[ to ,build a ,wim%ur/ ,ma*9e4 4444444444444444444444444444444 ,exp]im5ts ) ,/atic ,electrical ,app>atus4 4444444444444444444 ,,*apt] ,,ii4 ,,cells ,,& ,,batt]ies4 4444444444444444444444444444444444 ,! ,voltaic ,cell4 4444444444444444444444444444444444444444 4444444 ,homemade ,batt]ies4 4444444444444444444444444444444444444444 44444 ,batt]y ,solutions or ,electrolytes4 444444444444444444444444444444 ,connect+ ,cells4 4444444444444444444444444444444444444444 4444444 ,/orage or ,second>y ,cells4 4444444444444444444444444444444444444 ,an ,exp]im5tal ,/orage ,cell4 44444444444444444444444444444444444 ,a ,homemade ,/orage ,cell4 4444444444444444444444444444444444444444 ,re*>g+ & ,c>+ = ,/orage ,cells4 444444444444444444444444 ,,*apt] ,,iii4 ,,h[ ,,to ,,r$uce ,,! #aaj ,v4 ,d4,c4 ,,or ,a4,c4 ,,to ,a ,,l[] ,,voltage ,,= ,,exp]im5tal ,,purposes4 44444444444444444444444444444444 ,,*apt] ,,iv4 ,,h[ ,,an ,,alt]nat+ ,,curr5t ,,may ,,be ,,*ang$ ,,into ,,direct ,,curr5t ,,by ,,means ,,( ,,an ,,electrolytic ,,rectifi]4 44444444444444444444 ,,*apt] ,v4 ,,h[ ,,to ,,build ,a ,,/ep-,,d[n ,,trans=m] ,,= ,,r$uc+ ,,! #aaj ,,volt ,a4 ,c4 ,,= ,,exp]im5tal ,,purposes4 44444444444444444444444444444 ,,*apt] ,,vi4 ,,electric ,,measur+ ,,in/rum5ts 444444444444444444444444 ,galvanomet]s1 ,ammet]s1 ,voltmet]s4 ,h[ to ,make a ,galvanomet]4 4 ,! ,con/ruction ( ,ammet]s & ,voltmet]s4 44444444444444444444 ,,*apt] ,,vii4 ,,curr5t ,,control ,,devices4 44444444444444444444444444444 ,h[ to ,make a ,pole ,*ang+ ,swit* or ,curr5t ,rev]ses ,h[ to ,rev]se a ,small ,motor4 4444444444444444444444444444444444444444 44 ,h[ to ,make a ,small ,batt]y ,rheo/at = ,regulat+ ! ,spe$ ( ,small ,motors1 ,etc4 4444444444444444444444444444444444444444 444444 ,,*apt] ,,viii4 ,,h[ ,,to ,,make ,a ,,telegraph ,,key ,,& ,,s\nd] ,,& ,,in/all ,a ,,telegraph ,,l9e4 4444444444444444444444444444444444444444 44444444444 ,,*apt] ,,ix4 ,,h[ ,,to ,,make ,,& ,,in/all ,a ,,telephone4 444444444444444444 ,,*apt] ,x4 ,,m$ical ,,coils ,,& ,,%ock+ ,,coils4 4444444444444444444444 ,,*apt] ,,xi4 ,,! ,,con/ruction ,,( ,,sp>k ,,coils4 4444444444444444444444 ,exp]im5t #a--;,an ,imitation ,gassiot's ,cascade4 44444444444444444444 ,exp]im5t #b--;,a ,gho/ly ,light 444444444444444444444444444444444444 ,exp]im5t #c--,light+ ,geissl] ,tubes4 444444444444444444444444444 ,exp]im5t #d--;,flick]+ ,light4 4444444444444444444444444444444444 ,exp]im5t #e--,rotat+ a ,geissl] ,tube4 44444444444444444444444444 ,exp]im5t #f--;,fluoresc5t ,writ+4 4444444444444444444444444444444 ,exp]im5t #g--;,an ,electric ,bomb4 4444444444444444444444444444444444 ,exp]im5t #h--;,electrify+ ! ,g>bage ,c4 4444444444444444444444 ,exp]im5t #i--;,h[ to ,make an ,electric ,sp>k ,photograph ,itself4 444 ,,*apt] ,,xii4 ,,h[ ,,to ,,make ,a ,,dynamo-,,motor 444444444444444444444444444 ,,*apt] ,,xiii4 ,,an ,,electric ,,batt]y ,,motor4 44444444444444444444444444 ,,*apt] ,,xiv4 ,,h[ ,,to ,,build ,,an ,,electric ,,eng9e4 444444444444444444444 ,,*apt] ,,xv4 ,,m9iature ,,batt]y ,,light+4 444444444444444444444444444 ,,*apt] ,,xvi4 ,,coh]] ,,outfits ,,= ,,wireless ,,telegraphy4 4444444444444 ,,*apt] ,,xvii4 ,,h[ ,,to ,,build ,a ,,tesla ,,high ,,frequ5cy ,,coil4 44444444444 ,,*apt] ,,xviii4 ,,an ,,exp]im5tal ,,wireless ,,telephone4 4444444444444444 ,,*apt] ,,xix4 ,,miscellane\s ,,exp]im5ts ,,& ,,app>atus4 4444444444444 ,,electrolysis4 4444444444444444444444444444444444444444 44444444444 ,,electroplat+4 4444444444444444444444444444444444444444 444444444 ,,electric ,,curr5t ,,g5]at$ ,,by ,,heat4 44444444444444444444444444444 ,a ,,h&y ,,light4 4444444444444444444444444444444444444444 4444444444 ,,an ,,exp]im5tal ,,arc ,,lamp4 444444444444444444444444444444444444444 ,a ,,magnetic ,,div]4 4444444444444444444444444444444444444444 4444444 ,,! ,,magnetic ,,fi%4 4444444444444444444444444444444444444444 444444 ,a ,,magnetic ,,cl[n4 4444444444444444444444444444444444444444 4444444 ,,an ,,electric ,,breeze4 4444444444444444444444444444444444444444 44444 ,a ,,/atic ,,motor4 4444444444444444444444444444444444444444 444444444 ,,fig4 #a4--;,a simple ,wim%ur/ ,ma*9e :i* any boy c easily make4 ,p ,p1 ,plates2 ,,br1 ,neutralizes2 ,c ,r1 ,collectors2 ,,dr1 ,dis*>ge ,rods2 ,j ,j1 ,leyd5 ,j>s2 ,h ,h1 ,insulat+ ,h&les2 ,c1 ,crank2 ,u1 ,upright2 ,b1 ,belt4 4444444444444444444444444444444444444444 444444444444444444444 ,,fig4 #b4--,! plates = ! ,/atic ,ma*9e are made ( h>d rubb] & are #g in*es 9 diamet]4 ,ea* plate c>ries sixte5 t9foil sectors4 4444444444444444444444444444444444444444 444444444444444444 ,,fig4 #c4--,! details ( ! ,t9foil ,sector4 ,sixte5 are requir$ = ea* plate4 ,!y are /uck to ! plates ) %ellac4 444444444444 ,,fig4 #d4--;,details ( ! ,groov$ ,pulley1 atta*$ to ea* plate4 ,! ,pulleys are turn$ out ( wood4 44444444444444444444444444444444444 ,,fig4 #e4--,! base ( ! ,wim%ur/ ,ma*9e4 ,all woodwork ab\t ! ma*9e %\ld be c>efully dri$ & !n %ellac$ s t x _c absorb any moi/ure4 444444444444444444444444444444444444444 ,,fig4 #f4--;,details ( "o ( ! ,uprights :i* support ! ,plates1 ,driv+ ,pulleys1 etc4 ,^!1 be+ made ( wood1 %\ld also be dri$ & %ellac$ s t !y _c absorb moi/ure4 4444444444 ,,fig4 #g4--,%[+ ! ,two ,uprights 9 position on ! ,base4 444444444 ,,fig4 #h4--,! ,driv+ ,pulleys4 ,^! are turn$ out ( wood & m\nt$ on a %aft hav+ a ,crank at "o end4 444444444444444444444 ,,fig4 #i4--,! ,crank is b5t out ( a piece ( #c_/af rod1 #g in*es long1 into ! %ape %[n4 4444444444444444444444444444444444444444 44444 ,,fig4 #aj4--,! ,collector ) ! ,dis*>ge ,rods1 etc1 9 position4 ,a is ! ,brass ,ball =m+ "o t]m9al ( ! gap across :i* ! sp>ks jump4 ,b is ano!r ,brass ,ball screw$ onto ! end ( ! ,collector ,rod & hav+ a hole 9 x1 ?r\gh :i* ! ,dis*>ge ,rod slips4 ,,cc are two ?read$ ,wa%]s us$ to clamp ! ,dis*>ge ,rod 9 place4 4444444444444444444444444444444444444444 4444444444444 ,,fig4 #aa4--,%[+ h[ ,b9d+ ,po/s may be sub/itut$ = ,r\nd ,balls on ! ,collector ,rods4 44444444444444444444444444444444444444 ,,fig4 #ab4--;,details ( ! ,dis*>g] ,rods4 44444444444444444444444444 ,,fig4 #ac4--,! ,support+ ,b> ^u :i* ! ,collector ,rods are m\nt$4 ,made ( h>d rubb] s z to be a p]fect ,insulator4 44444 ,,fig4 #ad4--,! ,neutraliz]s4 ,two are requir$4 ,!y are b5t out ( ,brass ,rod & fitt$ ) a ,t9sel ,tuft at ea* end4 ,! c5tre piece ^u :i* ! ,rod is m\nt$ %\ld be ( ,h>d ,rubb]4 4444 ,,fig4 #ae4--;,details ( ! ,leyd5 ,j>s4 ,!y are simply small ,te/ ,tubes1 coat$ inside & outside ) t9foil = ab\t two-?irds _! height & fitt$ ) a ,brass ,rod connect$ ) ! inside coat+4 4444444444444444444444444444444444444444 444444444444444444 ,,fig4 #af4--;,a ,l>ge ,leyd5 ,j> = exp]im5tal purposes4 444444444444 ,,fig4 #ag4--,%[+ h[ to ,dis*>ge a ,leyd5 ,j> ) a curv$ piece ( /iff wire fitt$ to a ,wood5 ,h&le4 44444444444444444444444444 ,,fig4 #ah4--,! ,lightn+ ,bo>d is simply a ,/rip ( ,glass cov]$ ) small ,t9foil ,squ>es4 ,x may be insulat$ by m\nt+ on a ,bottle4 ,! two ,wires atta*$ to ! wide ,t9foil ,/rips at ! ends ( ! ,bo>d are = connection to ! ,/atic ,ma*9e or ,leyd5 ,j>4 4444444444444444444444444444444444444444 444444444444444 ,,fig4 #ai4--;,a v pretty effect c be produc$ by arrang+ small t9foil /rips on ! ,glass 9 a ,patt]n4 ,ea* /rip %\ld be sep>at$ f ! o!r j f> en\gh = a ,sp>k to pass4 44444 ,,fig4 #bj4--;,a v pretty design made by arrang+ ! ,/rips 9 ! =m ( a ,sev5-po9t$ ,/>4 ,fl[]s1 initials or almo/ any patt]n may be made 9 ! same way4 444444444444444444444444444444 ,,fig4 #ba4--,! ,electric ,p>asol4 ,! upp] "r-h& corn] %[s a piece ( ,tissue ,pap] cut into ,/rips4 7#a7 ,is ! app>atus be=e ! ,tissue ,pap] is fa/5$ to ! ,cork4 7#b7 ,%[s ! complet$ ,p>asol & 7#c71 ! ,p>asol :5 connect$ to ! ma*9e & ! latt] is set 9 op]ation4 444444444444444444444444444444444444444 ,,fig4 #bb4--;,electric ,birds4 ,! ,birds are made ( ,tissue ,pap] & %\ld be ab\t ! size & %ape %[n 9 ! l[] "r-h& corn] ( ! illu/ration above4 444444444444444444444444444444444 ,,fig4 #bc4--;,electric ,acrobats4 ,! ,acrobats are made ( pap]4 ,! little figure 9 ! upp] "r-h& "p ( ! illu/ration is ! prop] size4 4444444444444444444444444444444444444444 4444444444 ,,fig4 #bd4--,! ,electric ,mort>4 ,c is ! ,mort>1 ,p ! ,p[d]1 ,b a ,small ,ball & ,w ,w ! two ,wires betwe5 :i* ! ,sp>k ignit+ ! p[d] takes place4 4444444444444444444444444444444444444444 444 ,,fig4 #be4--;,an ,electric ,:irligig4 44444444444444444444444444444444444 ,,fig4 #bf4--;,a ,voltaic ,cell4 ,a ,voltaic ,cell consi/s ( a ,/rip ( ,copp] & a ,/rip ( ,z9c imm]s$ 9 a dilute solution ( ,sulphuric ,acid4 4444444444444444444444444444444444444444 44444444444 ,,fig4 #bg4--,ord9>y ,jelly ,glasses1 ,tumbl]s1 ,fruit ,j>s1 etc1 make good ,j>s = small cells by cutt+ (f ! tops4 4444444444444444 ,,fig4 #bh4--;,a ,simple ,home-made ,cell4 444444444444444444444444444444444 ,,fig4 #bi4--;,a ,home-made ,batt]y hav+ two ,c>bon ,plates ) a ,z9c ,rod betwe54 4444444444444444444444444444444444444444 44444444444444 ,,fig4 #cj4--,! ,elem5ts = a ,simple ,home-made ,cell compos$ ( two ,c>bon ,rods & "o ,z9c ,rod clamp$ betwe5 two ,wood5 ,/rips4 444 ,,fig4 #ca4--;,f\r ,c>bon ,rods & "o ,z9c ,rod arrang$ to =m ! ,elem5ts ( a ,cell4 4444444444444444444444444444444444444444 4444444 ,,fig4 #cb4--;,a ,batt]y ( ,?ree ,cells arrang$ s t !y c all be lift$ out ( ! solution at once4 4444444444444444444444444444444 ,,fig4 #cc4--,%[+ h[ ,cells are arrang$ :5 !y are connect$ 9 ,s]ies4 ,! ,voltage ( ,six ,dry ,cells connect$ 9 s]ies z above w\ld be approximately #f x #a4e or #i ,volts4 444444444444444444444444 ,,fig4 #cd4--,%[+ ,six ,dry ,cells connect$ 9 ,multiple4 ,! ,voltage ( su* an arrangem5t w\ld only be #a4e1 b ! ,amp]age available w\ld be six times t possible f ,cells connect$ z 9 ,figure #cc4 4444444444444444444444444444444444444444 44444444444444444444444 ,,fig4 #ce4--,%[+ h[ to connect a ,batt]y ( ,cells 9 ,s]ies-,multiple4 4444444444444444444444444444444444444444 4444444444 ,,fig4 #cf4--;,batt]y ,connectors l t %[n above c be obta9$ = #a #a_/b c5ts ea* & w be f\nd to be v h&y4 4444444444 ,,fig4 #cg4--;,a ,simple ,exp]im5tal ,/orage ,batt]y consi/+ ( two ,lead ,plates imm]s$ 9 ,dilute ,sulphuric ,acid4 44444444444444444444 ,,fig4 #ch4--,%[+ h[ to *>ge a ,simple ,/orage ,cell compos$ ( two ,lead ,plates imm]s$ 9 ,sulphuric ,acid by connect+ x to two ,bi*romate ( ,pota% ,cells4 444444444444444444444444444444444444444 ,,fig4 #ci4--,%[+ h[ ! ,plates = a ,/orage ,cell may be made f ,%eet ,lead by bor+ x full ( holes & fill+ ) pa/e4 44444 ,,fig4 #dj4--;,a set ( ?ree ,plates compos$ ( ,"o ,positive & ,?ree ,negatives assembl$ to =m a ,cell4 4444444444444444444444444444444 ,,fig4 #da4--;,glass & ,rubb] ,/orage ,cell ,j>s :i* are on ! m>ket = ! ,electrical ,exp]im5t] & may be pur*as$ v reasonably4 4444444444444444444444444444444444444444 444444444444444 ,,fig4 #db4--;,an empty ,/orage ,cell ,grid & also a ,pa/$ ,plate bo? ( :i* are on ! m>ket = exp]im5t]s :o wi% to build _! own ,cells4 4444444444444444444444444444444444444444 4444444444444444 ,,fig4 #dc4--,two ,negative ,plates burn$ toge!r & ! ,connect+ ,lug us$4 4444444444444444444444444444444444444444 44444444444444444 ,,fig4 #dd4--,! ,elem5ts ( a ,/orage ,cell compos$ ( two ,negative ,plates & "o ,positive ,plate 9 _! prop] position4 44444444444 ,,fig4 #de4--,?ree diff]5t sizes ( ,/orage ,cells :i* may be pur*as$ ready made or built by ! exp]im5t] out ( prep>$ mat]ials z expla9$4 4444444444444444444444444444444444444444 444 ,,fig4 #df4--;,a ,hydromet] = prep>+ & te/+ ! ,acid ,solution = ,/orage ,batt]ies4 4444444444444444444444444444444444444444 4444 ,,fig4 #dg4--,! prop] way ( ,re*>g+ ,/orage ,cells f ! #aaj ,volts ,d4 ,c4 ,supply 9 s]ies ) a set ( ,lamps4 44444444444444444 ,,fig4 #dh4--;,a ,lamp ,bank consi/+ ( a ,set ( #aaj-,volt ,lamps connect$ ,multiple & arrang$ to be plac$ 9 s]ies ) any device x is desir$ to use on ! #aaj-,volt ,curr5t4 444444444444444444444444444 ,,fig4 #di4--;,a ,s+le ,cell ( ,electrolytic ,rectifi]4 44444444444444444 ,,fig4 #ej4--;,an ,electrode cut out ( ,%eet ,metal4 ,! top is b5t ov] at "r angles & drill$ s t x c be m\nt$ on ! und]side ( ! cov]4 4444444444444444444444444444444444444444 444 ,,fig #ea4--;,a ,ca/ ,electrode w la/ mu* long] ?an "o cut f ,%eet ,metal4 ,ca/ ,electrodes l t above are on ! m>ket & c be pur*as$ v reasonably4 444444444444444444444444444444444 ,,fig4 #eb4--;,a complet$ s+le ,cell ,rectifi]4 ,! "r h& sket* %[s h[ ! ,electrodes are m\nt$ on ! und]side ( ! cov]4 ,,fig4 #ec4--;,a ,diagram %[+ h[ a ,rectifi] cuts (f "o-half ( ! ,alt]nat+ ,curr5t ,wave & *anges x into ,pulsat+ ,direct ,curr5t4 4444444444444444444444444444444444444444 444444444444444444 ,,fig4 #ed4--;,circuit %[+ h[ a ,s+le ,cell ( ,rectifi] %\ld be connect$ 9 s]ies ) a ,lamp ,bank to ,re*>ge a ,/orage ,cell4 ,a is ! ,alum9um ,plate & ,l ! ,lead or ,iron ,plate4 444444444444444 ,,fig4 #ee4--;,diagram %[+ ! ,diff]5ce 9 ,curr5t aft] x has be5 pass$ ?r\gh a ,s+le ,cell or ,rectifi] & aft] pass+ ?r\gh a ,f\r-,cell ,rectifi]4 4444444444444444444444444444444444444444 4444 ,,fig4 #ef4--;,diagram %[+ h[ a ,f\r-,cell ,rectifi] is connect$4 ,! ,alt]nat+ ,curr5t ,s\rce is connect$ to ,c & ,d4 ,! ,direct ,curr5t is tak5 (f at ,a & ,b4 ,! ,electrodes m>k$ ,a1 ,a1 ,a1 ,a are ! ,alum9um ,electrodes4 ,l1 ,l1 ,l1 ,l may be ,lead or ,iron4 444444 ,,fig4 #eg--;,a ,complete ,f\r-,cell ,rectifi] connect$ toge!r & ,m\nt$ 9 a ,tray4 4444444444444444444444444444444444444444 44444444 ,,fig4 #eh4--;,details ( ! two diff]5t ,pieces ( ,%eet ,iron us$ 9 build+ up ! ,core4 ,suffici5t ( ea* piece are requir$ to =m a pile ( ea* ?ree-qu>t]s ( an in* ?ick4 4444444444444444444 ,,fig4 #ei4--,! ,me?od us$ 9 pil+ up ! ,/rips to ,assemble ! ,core4 4444444444444444444444444444444444444444 444444444444444444444 ,,fig4 #fj4--;,assembly ( ! ,core4 444444444444444444444444444444444444 ,,fig4 #fa4--;,details ( ! ,prim>y & ,second>y ,w9d+s4 44444444444 ,,fig4 #fb4--,%[+ ! ,core completely assembl$ ) ! ,prim>y & ,second>y 9 position4 ,p1 ,p are ! ,prim>y ,t]m9als4 #a1 #b & #c are ! ,second>y ,t]m9als4 44444444444444444444444444444444444444 ,,fig4 #fc4--,! ,/ep-d[n ,trans=m] m\nt$ on a ,wood5 ,base4 444444 ,,fig4 #fd4--;,a detail$ ,draw+ %[+ h[ ! ,sides ( ! ,case are =m$ by b5d+ a long /rip ( ,%eet ,iron at f\r po9ts4 444444 ,,fig4 #fe4--;,details ( ! ,top & ,bottom ( ! ,case4 444444444444444 ,,fig4 #ff4--,! complet$ ,trans=m]4 4444444444444444444444444444444 ,,fig4 #fg4--;,a ,simple ,galvanomet]4 44444444444444444444444444444444444 ,,fig4 #fh4--;,details ( ! ,bobb94 44444444444444444444444444444444444 ,,fig4 #fi4--;,details ( ! ,armature1 ,be>+s & ,po9t]4 44444444444 ,,fig4 #gj4--;,a complete ,voltmet] hav+ ! ,scale at ! top4 44444444 ,,fig4 #ga--;,an ,ammet] s con/ruct$ t ! ,scale is at ! bottom4 4 ,,fig4 #gb4--,%[+ h[ ! ,armature1 ,%aft & ,po9t] are assembl$ = a ,met] hav+ ! ,scale at ! bottom4 44444444444444444444444 ,,fig4 #gc4--;,details ( ! ,wood5 ,p>ts :i* =m ! ,case4 444444444 ,,fig4 #gd4--,%[+ h[ ! ,app>atus is arrang$ & connect$ = calibrat+ ! ,ammet]4 4444444444444444444444444444444444444444 44 ,,fig4 #ge4--,%[+ h[ ! ,app>atus is arrang$ & connect$ = calibrat+ ! ,voltmet]4 4444444444444444444444444444444444444444 ,,fig4 #gf4--;,a ,pole *ang+ ,swit* = rev]s+ ,small ,motors or ! direction ( an ,electric ,curr5t4 444444444444444444444444444444444 ,,fig4 #gg4--,top view ( a small ,batt]y ,rheo/at 444444444444444444444 ,,fig4 #gh4--;,details ( ! ,rheo/at ,base4 ,! l[] "p ( ! illu/ration is a cross section4 4444444444444444444444444444444444 ,,fig4 #gi4--,look+ at ! ,base f ! bottom %[+ ! grooves 9 :i* ! ,wires are laid4 4444444444444444444444444444444444444444 4 ,,fig4 #hj4--,! ,g]man-silv] ,resi/ance ,wire is w\nd ar\nd a ,fibre ,/rip4 4444444444444444444444444444444444444444 44444444444444444444 ,,fig4 #ha4--,! ,lev]1 ,knob1 ,b9d+ ,po/s1 etc4 444444444444444444444 ,,fig4 #hb4--,! complet$ ,rheo/at4 4444444444444444444444444444444444 ,,fig4 #hc4--,key ,frame4 4444444444444444444444444444444444444444 4444444 ,,fig4 #hd4--,s\nd] ,frame4 4444444444444444444444444444444444444444 444 ,,fig4 #he4--,! ,electro ,magnets4 4444444444444444444444444444444444444 ,,fig4 #hf--,! ,s\nd] ,armature4 4444444444444444444444444444444444444 ,,fig4 #hg4--,s\nd] ,frame ) ,lev] 9 ,position4 44444444444444444444 ,,fig4 #hh4--,top ,view ( ,complet$ ,in/rum5t 4444444444444444444444444 ,,fig4 #hi4--,side ,view ( ,key4 4444444444444444444444444444444444444444 ,,fig4 #ij4--,key & ,circuit ,clos+ ,lev]s4 44444444444444444444444444 ,,fig4 #ia4--;,am]ican ,morse ,code4 4444444444444444444444444444444444444 ,,fig4 #ib4--;,circuit = ,two ,in/rum5ts4 44444444444444444444444444444 ,,fig4 #ic4--,! ,wood5 ,back = ! ,telephone4 44444444444444444444444 ,,fig4 #id4--,! ,complete ,telephone4 4444444444444444444444444444444444 ,,fig4 #ie4--;,details ( ! ,receiv] ,hook4 4444444444444444444444444444 ,,fig4 #if4--,%[+ h[ ! ,pu% ,button is arrang$4 44444444444444444 ,,fig4 #ig4--;,circuit %[+ h[ to connect two ,telephone ,/ations to ! ,l9e4 4444444444444444444444444444444444444444 44444444444444444 ,,fig4 #ih4--;,bobb9 = ,m$ical ,coil4 444444444444444444444444444444444 ,,fig4 #ii4--;,bobb9 ) ,w9d+4 4444444444444444444444444444444444444 ,,fig4 #ajj4--;,con/ruction ( ! ,core4 4444444444444444444444444444444 ,,fig4 #aja4--,vibrator ,p>ts & ,core ,cap4 4444444444444444444444444444 ,,fig4 #ajb4--,regulator ,tube4 4444444444444444444444444444444444444444 4 ,,fig4 #ajc4--,! ,base ) ,location ( ,holes4 444444444444444444444444 ,,fig4 #ajd4--,top ,view ( ,f9i%$ ,coil4 444444444444444444444444444444 ,,fig4 #aje4--,side ,view ( ,complet$ ,coil4 4444444444444444444444444444 ,,fig4 #ajf4--,vibrator ,p>ts4 4444444444444444444444444444444444444444 4 ,,figs4 #ajg & #ajh4--,two ,types ( ,h&les4 44444444444444444444444444 ,,fig4 #aji4--;,induction or ,sp>k ,coil4 44444444444444444444444444444444 ,,fig4 #aaj4--,! ,prim>y & ,core4 44444444444444444444444444444444444 ,,fig4 #aaa4--,! ,second>y ,w9d+4 4444444444444444444444444444444444 ,,fig4 #aab4--,! ,fix$ ,cond5s]4 444444444444444444444444444444444444 ,,fig4 #aac4--;,details ( ! ,wood5 ,coil ,heads4 44444444444444444444444 ,,fig4 #aad4--;,details ( ! ,wood5 ,base4 44444444444444444444444444444 ,,fig4 #aae4--;,details ( ! ,int]rupt]4 ,! ,spr+ & ,/&>d = ! ,"o in* coil %\ld be made "o-qu>t] ( an in* long]4 444 ,,fig4 #aaf4--,! tube4 4444444444444444444444444444444444444444 4444444 ,,fig4 #aag4--,! ,bridge4 4444444444444444444444444444444444444444 44444 ,,fig4 #aah4--,section ( ! ,sp>k ,coil %[+ ! arrangem5t ( ! ,p>ts4 4444444444444444444444444444444444444444 44444444444444444444 ,,fig4 #aai4--;,end ,view ( ! ,complete ,coil4 44444444444444444444444444 ,,fig4 #abj4--,side ,view ( ! ,complet$ ,coil4 444444444444444444444444 ,,fig4 #aba4--;,diagram ( ,connections4 444444444444444444444444444444444 ,,fig4 #abb4--,p]spective view ( ,coil %[+ names ( ! v>i\s p>ts4 4444444444444444444444444444444444444444 44444444444444444444 ,,fig4 #abc--;,front view ( ! ,field ,ca/+4 4444444444444444444444444 ,,fig4 #abd4--,side elevation ( ! ,field ,ca/+4 44444444444444444444 ,,fig4 #abe4--;,details ( ! ,armature4 44444444444444444444444444444444 ,,fig4 #abf4--,! ,commutator4 4444444444444444444444444444444444444444 4 ,,fig4 #abg4--,! ,armature & ,commutator ,assembl$ on ! ,%aft ready = w9d+4 4444444444444444444444444444444444444444 44444444444444 ,,fig4 #abh4--;,details ( ! ,wood5 ,base4 44444444444444444444444444444 ,,fig4 #abi4--;,details ( ! ,be>+s4 44444444444444444444444444444444 ,,fig4 #acj4--,! ,pulley4 4444444444444444444444444444444444444444 44444 ,,fig4 #aca4--,! ,bru%es4 4444444444444444444444444444444444444444 4444 ,,fig4 #acb4--,! ,complet$ ,dynamo4 44444444444444444444444444444444444 ,,fig4 #acc4--,! complet$ ,electric ,motor4 444444444444444444444444444 ,,fig4 #acd4--;,details ( ! ,field ,frame4 44444444444444444444444444444 ,,fig4 #ace4--,! ,assembl$ ,field ready = ,w9d+4 444444444444444444 ,,fig4 #acf4--;,details ( ! ,armature ,lam9ation4 444444444444444444444 ,,fig4 #acg4--,! ,armature assembl$ on ! ,%aft ready to ,w9d4 444444 ,,fig4 #ach4--,! ,commutator4 4444444444444444444444444444444444444444 4 ,,fig4 #aci4--;,diagram %[+ h[ ! ,armature ,coils are connect$ to ! ,commutator ,sections4 4444444444444444444444444444444444444444 44 ,,fig4 #adj4--,! ,be>+s4 4444444444444444444444444444444444444444 444 ,,fig4 #ada4--,! ,bru%es4 4444444444444444444444444444444444444444 4444 ,,fig4 #adb4--,! ,fibre ,block = support+ ea* ,bru%4 44444444444444 ,,fig4 #adc4--;,complet$ ,electric ,eng9e4 444444444444444444444444444444 ,,fig4 #add4--,! ,eng9e ,base4 4444444444444444444444444444444444444444 ,,fig4 #ade4--;,details ( ! ,electromagnet ,bobb94 44444444444444444444 ,,fig4 #adf4--;,details ( ! ,eng9e ,frame4 4444444444444444444444444444 ,,fig4 #adg--,! ,be>+s4 4444444444444444444444444444444444444444 4444 ,,fig4 #adh4--;,details ( ! ,%aft4 44444444444444444444444444444444444 ,,fig4 #adi4--,! ,armature1 ,armature ,be>+ & ,connect+ ,rod4 444444 ,,fig4 #aej4--,! ,bru%es4 4444444444444444444444444444444444444444 4444 ,,fig4 #aea4--;,a ,fly:eel may be cut f %eet iron4 444444444444444444 ,,fig4 #aeb4--,small ,tung/5 ,batt]y ,lamps4 444444444444444444444444444 ,,fig4 #aec4--;,a ,simple ,light+ ,arrangem5t4 44444444444444444444444444 ,,fig4 #aed4--,%[+ ! diff]5ces betwe5 ! ,c&elabra1 ,s+le ,ediswan & ,d\ble ,ediswan ,types ( ,lamp ,bases4 4444444444444444444 ,,fig4 #aee4--,m9iature ,sockets ( ! types kn[n z ,flat ,base ,porcela91 ,p9 & ,wea!rpro(4 44444444444444444444444444444 ,,fig4 #aef4--;,connections = a #b4h ,volt ,lamp4 444444444444444444444444 ,,fig4 #aeg4--;,a ,m9iature ,base ,tung/5 ,filam5t ,batt]y ,lamp = small light+4 4444444444444444444444444444444444444444 44444444444444444 ,,fig4 #aeh4--;,a ,tung/5 ,automobile ,lamp ) ,ediswan ,base4 44444444444 ,,fig4 #aei4--,lamps ,controll$ by ,"o ,swit*4 4444444444444444444444444 ,,fig4 #afj4--,lamps ,controll$ by ,sep>ate swit*es4 444444444444444444 ,,fig4 #afa4--;,d\ble ,control ,sy/em4 4444444444444444444444444444444444 ,,fig4 #afb4--,! ,coh]] ,details4 444444444444444444444444444444444444 ,,fig4 #afc4--,! ,complete ,coh]]4 44444444444444444444444444444444444 ,,fig4 #afd4--,pony ,type ,relay4 4444444444444444444444444444444444444444 ,,fig4 #afe4--;,connections = ! ,receiv+ ,set4 4444444444444444444444 ,,fig4 #aff4--;,coh]]1 ,decoh]] & ,relay ,connections4 444444444444444 ,,fig4 #afg4--;,h[ ! ,transmitt] is ,connect$4 44444444444444444444444 ,,fig4 #afh4--,! ,complete ,sp>k ,gap4 444444444444444444444444444444444 ,,fig4 #afi4--;,details ( ,sp>k ,gap4 44444444444444444444444444444444444 ,,fig4 #agj4--,tesla ,coil ,circuits4 444444444444444444444444444444444444 ,,fig4 #aga4--,second>y ,tube4 4444444444444444444444444444444444444444 4 ,,fig4 #agb4--;,details ( ! ,second>y ,heads4 4444444444444444444444444 ,,fig4 #agc4--;,details ( ! ,prim>y ,head4 4444444444444444444444444444 ,,fig4 #agd4--,prim>y ,cross ,b>4 44444444444444444444444444444444444444 ,,fig4 #age4--;,front ,view ( ! complet$ ,tesla ,coil4 44444444444444444 ,,fig4 #agf--,side ,view ( ! complet$ ,tesla ,coil4 4444444444444444444 ,,fig4 #agg4--;,diagram ( connections = op]at+ ! ,coil4 4444444444 ,,fig4 #agh4--,plate ,glass ,cond5s]4 4444444444444444444444444444444444 ,,fig4 #agi4--,:5 a ,b> ,magnet is plung$ into a ,holl[ ,coil ( ,wire1 a ,mom5t>y ,curr5t ( ,electricity is ,g5]at$4 44444444444444444444 ,,fig4 #ahj4--,magnetic ,phantom %[+ ! ,l9es ( ,=ce ab\t a ,b> ,magnet4 4444444444444444444444444444444444444444 4444444444444444444 ,,fig4 #aha4--,magnetic ,phantom ab\t a ,coil ( ,wire c>ry+ a curr5t4 ,,fig4 #ahb4--;,illu/rat+ ! ,pr9ciple ( ! ,induction ,wireless ,telephone4 4444444444444444444444444444444444444444 4444444444444444 ,,fig4 #ahc4--,%[+ h[ ! ,coils may be =m$ by w9d+ ar\nd nails set 9 a circle 9 ! ,floor4 4444444444444444444444444444444 ,,fig4 #ahd4--;,circuit ,diagram %[+ h[ ! ,coil is connect$ s z to s]ve = ei!r transmitt+ or receiv+4 44444444444444444444444 ,,fig4 #ahe4--;,app>atus = ,electrolysis ,exp]im5t4 444444444444444444 ,,fig4 #ahf4--;,electroplat+ ,tank4 444444444444444444444444444444444444 ,,fig4 #ahg4--;,g5]at+ ,electric ,curr5t by ,heat4 44444444444444444444 ,,fig4 #ahh4--;,a ,h&y ,light4 4444444444444444444444444444444444444444 44 ,,fig4 #ahi4--;,exp]im5tal ,arc ,lamp4 4444444444444444444444444444444444 ,,fig4 #aij4--,! ,magnetic ,div]4 4444444444444444444444444444444444444 ,,fig4 #aia4--,! ,magnetic ,fi%4 44444444444444444444444444444444444444 ,,fig4 #aib4--,! ,magnetic ,cl[n4 4444444444444444444444444444444444444 ,,fig4 #aic4--;,an ,electric ,breeze4 4444444444444444444444444444444444444 ,,fig4 #aid4--,! ,/atic ,motor4 444444444444444444444444444444444444444 ,,*apt] ,i4 ,,/atic ,,electrical ,,app>atus 99,/atic ,electricity4 ,h[ to ,build a ,wim%ur/ ,ma*9e4 ,exp]im5ts ) ,/atic ,electrical ,app>atus499 99,/atic ,electricity99 is an extremely int]e/+ subject = ! amateur exp]im5t]1 9 view ( ! _m spectacul> exp]im5ts :i* may be p]=m$ ) x4 ,! numb] ( su* exp]im5ts is almo/ unlimit$4 ,/atic electricity 0 ! fir/ evid5ce ( ! wond]ful =ce :i* 9 ! pres5t day moves tra9s1 lights our homes1 etc41 to come to ! notice ( man4 ,long be=e ! days ( batt]ies1 dynamos1 telegraphs1 electric lights & be=e1 p]haps1 su* ?+s 7 ev5 dream$ (1 /atic electricity absorb$ ! att5tion ( sci5ti/s1 & ! names ( "s ( ! _w's greate/ m5 su* z = in/ance1 ,ari/otle1 ,rog] ,bacon1 ,gilb]t1 ,boyle1 ,newton1 ,frankl91 etc41 are closely l9k$ ) its hi/ory4 ,x is probably safe to say t exp]im5ts ) /atic electricity l$ ! fam\s ,italian1 ,galvani1 to ! discov]y ( ! sort ( electricity call$ 99galvanic99 curr5ts1 & to ! batt]y4 ,galvanic curr5t is ! sort ( electricity produc$ by batt]ies & has ! same prop]ties 9 _m ways z t g5]at$ by huge dynamos 9 ! p[] h\ses ( to-day4 ,! mod]n boy c duplicate ^! old exp]im5ts f> m easily & on a l>g] scale ?an any ( ! old sci5ti/s c\ld1 ow+ to ! fact t he is suppli$ ) explicit directions & c easily obta9 ! necess>y mat]ials at a neighbor+ h>dw>e or electrical /ore1 :]eas m5 l ,newton & ,frankl9 n only _h to 99devise99 or 99inv5t99 _! own app>atus b make _! mat]ials z well4 ,h[ to ,build a ,wim%ur/ ,ma*9e4 ,/atic electricity & lightn+ are ! same ?+4 ,a boy c produce /atic electricity 9 small quantities by rubb+ a glass rod ) a piece ( flannel or silk4 ,illu/ration3 ,,fig4 #a4--;,a simple ,wim%ur/ ,ma*9e :i* any boy c easily make4 ,p ,p1 ,plates2 ,,br1 ,neutralizes2 ,c ,r1 ,collectors2 ,,dr1 ,dis*>ge ,rods2 ,j ,j1 ,leyd5 ,j>s2 ,h ,h1 ,insulat+ ,h&les2 ,c1 ,crank2 ,u1 ,upright2 ,b1 ,belt4 ,rub ! rod briskly & !n hold x ov] "s t9y bits ( pap] or specks ( du/ & wat* !m jump up to meet ! rod1 j z if ! latt] 7 a magnet attract+ small tacks or nails4 ,x is /atic electricity :i* gives ! rod ?is wond]ful p[]4 ,if y rub ! rod briskly & !n hold x close to y\r *eek1 y w feel a slight tickl+ & he> a fa9t crackl+ s\nd4 ,if ?is is done 9 ! d>k y may be able to see a v fa9t phosphoresc5t light or ev5 small sp>ks4 ,! quantity ( electricity produc$ 9 ?is mann] by rubb+ a glass rod is extremely limit$ & :ile a numb] ( v int]e/+ & in/ructive exp]im5ts may be p]=m$ 9 ?is mann]1 ! mo/ spectacul> ones are only possible ) ! aid ( a /atic-ma*9e4 ,illu/ration3 ,,fig4 #b4--,! plates = ! ,/atic ,ma*9e are made ( h>d rubb] & are #g in*es 9 diamet]4 ,ea* plate c>ries sixte5 t9foil sectors4 ,! mo/ practical =m ( /atic ma*9e is t kn[n z ! ,wim%ur/4 ,x consi/s ( two circul> plates made ( glass or h>d rubb] arrang$ s t by turn+ a crank1 !y may be revolv$ 9 opposite directions4 ,on ^! plates are a numb] ( small /rips ( t9foil4 ,! /atic electricity is g5]at$ on ^! t9foil /rips & collect$ by two metal rods hav+ small p9s arrang$ along !m 9 a r[4 ,a simple =m ( ,wim%ur/ ma*9e :i* any boy c easily make is illu/rat$ 9 ,figure #a4 ,x w g5]ate consid]able /atic electricity & w make sp>ks two in*es long4 99,! ,plates99 on ^! ma*9es are h>d rubb]4 ,!y are illu/rat$ 9 ,figure #b4 ,glass is usually us$ = /atic ma*9e plates1 b has ! disadvantage ( break+ easily4 ,x is also h>d = ! "y exp]im5t] to cut out circul> glass plates & drill !m4 ,! au?or has _h v good success ) h>d rubb]4 ,illu/ration3 ,,fig4 #c4--,! details ( ! ,t9foil ,sector4 ,sixte5 are requir$ = ea* plate4 ,!y are /uck to ! plates ) %ellac4 ,two plates are requir$ = ! ma*9e4 ,!y %\ld be 9 ! =m ( circles sev5 in*es 9 diamet] & be p]fectly true4 ,!y ne$ to be only "o-sixte5? ( an in* ?ick4 ,! rubb] %\ld be p]fectly flat & n w>p$ at any po9t4 99,! ,sectors991 z ! t9foil /rips are call$1 are w$ge %ap$ pieces hav+ r\nd$ ends z %[n 9 ,figure #c4 ,!y %\ld be cut ( heavy t9foil4 ,?irty-two sectors are requir$1 sixte5 = ea* plate4 ,!y are sev5-sixte5?s ( an in* wide at ! top1 "o in* long & five-sixte5? ( an in* wide at ! bottom4 ,! plates %\ld be v c>efully clean$ by rubb+ ) a dry clo? & !n laid on a flat surface all ready to receive ! sectors4 ,! sectors %\ld be /uck to ! plates ) ?ick %ellac4 ,!y %\ld be arrang$ all on "o face1 symmetrically & at equal di/ances ap>t1 ) ! inn] ends re/+ on a circle f\r & "o-half in*es 9 diamet]4 ,ea* sector %\ld be c>efully press$ d[n on ! rubb] s t x /icks smoo?ly )\t any air bubbles or creases4 ,bo? plates %\ld be treat$ 9 ! same mann]4 ,illu/ration3 ,,fig4 #d4--;,details ( ! ,groov$ ,pulley1 atta*$ to ea* plate4 ,! ,pulleys are turn$ out ( wood4 99,! ,pulley99 illu/rat$ 9 ,figure #d is "o in* 9 diamet] & elev5-sixte5?s ( an in* ?ick4 ,two ( ^! pulleys w be requir$4 ,! hole ?r\gh ! c5tre %\ld be ab\t ?ree-sixte5?s ( an in* 9 diamet]4 ,"o pulley %\ld be atta*$ to ea* ( ! rubb] plates4 ,! l>ge face ( ! pulley %\ld be aga9/ ! face ( ! plate ^u :i* ! t9foil sectors are m\nt$4 ,! hole 9 ! c5tre ( ! pulley %\ld l9e up p]fectly ) a hole ( ! same size 9 ! c5tre ( ea* "o ( ! plates4 ,! plates are fa/5$ to ! pulleys by ?ree small brass nails driv5 into ! wood ?r\gh small holes 9 ! rubb]4 99,! ,base99 ( ! ma*9e is a rectangul> %ap$ piece ( wood six in*es long1 f\r in*es wide & ?ree-qu>t]s ( an in* ?ick4 ,a not*1 "o in* wide & "o-half an in* deep is cut 9 ! c5tre ( ! front & back z %[n 9 ,figure #e4 ,! purpose ( ^! not*es is to receive ! uprights4 99,! ,uprights99 are /rips ( wood1 sev5 in*es long1 "o in* wide & "o-half an in* ?ick4 ,! tipp] end ( ea* ( ! uprights is r\nd$ z %[n 9 ,figure #f4 ,illu/ration3 ,,fig4 #e4--,! base ( ! ,wim%ur/ ,ma*9e4 ,all woodwork ab\t ! ma*9e %\ld be c>efully dri$ & !n %ellac$ s t x _c absorb any moi/ure4 ,two holes %\ld be bor$ ?r\gh ea* ( ! uprights f front to back4 ,! l[] hole is ?ree-sixte5?s ( an in* 9 diamet] & two & "o-qu>t] in*es f ! bottom4 ,! upp] hole is six & "o-half in*es f ! bottom & is betwe5 "o-eigh? & ?ree-sixte5?s ( an in* 9 diamet] s t a ?ree-sixte5? rod driv5 into x w fit tightly4 ,! uprights %\ld be m\nt$ 9 position 9 ! base & fa/5$ ) screws4 ,! plates are m\nt$ betwe5 ! upp] ends ( ! uprights 9 ! position %[n 9 ,figure #a1 by driv+ a %ort piece ( #c_/af r\nd brass rod ?r\gh ! uprights into ! holes 9 ! c5tre ( ! pulleys4 ,! rod us$ to m\nt ! back plate %\ld be "o & "o-half in*es long & t us$ = ! front plate "o & five-eigh?s in*es long4 ,! #c_/af hole 9 ! pulleys %\ld be l>ge en\gh s t ! latt] w revolve freely4 ,! plates are revolv$ by two driv+ pulleys provid$ ) a crank = turn+4 99,! ,driv+ ,pulleys99 are %[n 9 ,figure #h4 ,!y are n s easy to make z ! small pulleys atta*$ to ! plates4 ,!y are turn$ out ( wood & %\ld be bo? alike4 ,! exact %ape & dim5sions are %[n 9 ! illu/ration4 ,! hole ?r\gh ! c5tre %\ld be a scant ?ree-sixte5?s ( an in* s t ! pulleys w =ce onto a #c_/af rod v tightly4 99,! ,crank99 is b5t out ( a piece ( brass or /eel rod ab\t sev5 in*es long4 ,! /raight portion1 =m+ ! %aft ^u :i* ! pulleys are m\nt$1 is ?ree & sev5-eigh?s in*es long4 ,! portion at "r angles to ?is1 =m+ :at is kn[n z ! ?r[ ( ! crank1 is "o in* & sev5-eigh?s4 ,! "p =m+ ! crank h&le is "o in* & "o-qu>t] long4 ,illu/ration3 ,,fig4 #f4--;,details ( "o ( ! ,uprights :i* support ! ,plates1 ,driv+ ,pulleys1 etc4 ,^!1 be+ made ( wood1 %\ld also be dri$ & %ellac$ s t !y _c absorb moi/ure4 ,! driv+ pulleys are plac$ betwe5 ! two /&>ds ) ! small project+ portions or bosses ne>e/ ! uprights4 ,! /raight portion ( ! crank %\ld !n be slipp$ ?r\gh ! hole 9 ! front upright & driv5 tightly into ! driv+ pulleys4 ,! driv+ pulleys %\ld fit s tightly onto ! %aft t !y w n slip4 ,! end ( ! %aft %\ld project ?r\gh ! pulleys f> en\gh s t is re/s 9 ! hole 9 ! re> /&>d4 ,! holes 9 ! uprights or /&>ds %\ld be j l>ge en\gh s t ! %aft w turn freely4 ,! driv+ pulleys %\ld be l9$ up s t ! groove 9 ea* comes directly "u ! groove 9 ! correspond+ pulley atta*$ to ! plate above4 99,! ,belts99 consi/ simply ( heavy cotton cord4 ,! re> belt %\ld be cross$ s t ! re> plate runs 9 ! opposite direction f ! front plate :5 ! crank is turn$4 ,! electricity is collect$ f ! sectors on ! plates by two 99,collectors499 ,^! are illu/rat$ 9 ,figure #aj & consi/s ( a piece ( #e_/cb brass rod1 ab\t six in*es long1 b5t into ! %ape %[n4 ,two small tufts ( t9sel are sold]$ to ! ,u-%ap$ portion ( ! collector s t :5 ! latt] is plac$ 9 its prop] position on ! ma*9e1 !y w bru% aga9/ ! t9foil-sectors z !y pass :5 ! plates revolve4 ,illu/ration3 ,,fig4 #g4--,%[+ ! ,two ,uprights 9 position on ! ,base4 ,! o!r end ( ! rod is ?read$ to fit into a hole 9 a small brass ball ab\t ?ree-eigh?s or "o-half in* 9 diamet]4 ,_m exp]im5t]s may h difficulty 9 secur+ a suitable brass ball = ?is purpose4 ,an ord9>y b9d+ po/ may be us$ in/ead4 ,! hole 9 ! bottom ( a b9d+ po/ is usually ?read$ to fit an #h-cb screw4 ,! end ( ! rod is j ! "r size to receive an #h-cb ?read & s !re %\ld be no tr\ble 9 gett+ ! p>ts to fit4 ,! brass ball is m>k$ ,a 9 ! illu/ration4 ,! ball is pref]able to ! b9d+ because x has no %>p corn]s f :i* ! electricity might leak4 ,/atic electricity leaks f %>p edges or corn]s & !y mu/ always be avoid$ z f> z possible 9 ! con/ruction ( /atic app>atus4 ,! end ( ! rod :]e x screws into ! ball or b9d+ po/ %\ld be ?read$ back = a di/ance ( ab\t ?ree-qu>t]s ( an in* & two brass nuts screw$ onto ! rod4 ,^! nuts are m>k$ ,c 9 ! illu/ration4 ,illu/ration3 ,,fig4 #h4--,! ,driv+ ,pulleys4 ,^! are turn$ out ( wood & m\nt$ on a %aft hav+ a ,crank at "o end4 ,! collectors are held 9 position by ! support+ b> illu/rat$ 9 ,figure #ac4 ,?is b> is made ( a /rip ( h>d rubb]1 five & "o qu>t] in*es long1 five-eigh?s ( an in* wide & ?ree-sixte5?s ( an in* ?ick4 ,?ree holes1 ea* five-?irty-seconds ( an in* 9 diamet]1 %\ld be bor$ 9 ! b>4 ,"o hole %\ld be exactly 9 ! c5tre & ! o!r holes sev5-sixte5?s ( an in* back f ! end4 ,! c5tre hole is slipp$ ov] ! end ( ! %aft :i* projects ?r\gh ! front /&>d support+ ! plate & ! b> fa/5$ across ! support at "r angles l a cross by driv+ 9 two small brass nails or screws ?r\gh holes made 9 ! rubb] = t purpose4 ,! ?read$ portion ( ! collector rods %\ld be slipp$ ?r\gh ! holes ne> ! ends ( ! h>d rubb] b> & clamp$ firmly 9 position by plac+ "o ( ! nuts ,c on ! back & ! o!r on ! front & tight5+ !m up4 ,! exact position ( ! collectors is be/ und]/ood f ,figure #a4 ,!y are lett]$ ,c ,r 9 ! illu/ration4 ,! brass balls ,b are screw$ onto ! ends ( ! rods aft] ! nuts h be5 tight5$4 ,ea* ( ^! balls %\ld h a hole1 "o-eigh? ( an in* 9 diamet] drill$ ?r\gh x at "r angles to ! collector rod4 ,! hole provid$ 9 ! b9d+ po/ = ! accommodation ( ! wire may be us$ 9 case b9d+ po/s are employ$ in/ead ( ! rods4 ,^! holes are to accommodate ! ,dis*>ge ,rods1 :i* are two r\nd brass rods1 "o-eigh? ( an in* 9 diamet] & ?ree & "o-half in*es long4 ,"o end ( ea* ( ! rods is fitt$ ) a small brass ball4 ,illu/ration3 ,,fig4 #i4--,! ,crank is b5t out ( a piece ( #c_/af rod1 #g in*es long1 into ! %ape %[n4 ,! o!r end ( ea* is provid$ ) a small insulat+ h&le4 ,a ,no4 #hjjc ,electrose ,knob is j ! ?+4 ,^! knobs are provid$ ) a ?read$ bu%+ s t !y may be screw$ onto ! rod4 ,! prop] position = ! dis*>ge rods is %[n 9 ,figure #a4 ,by slid+ ! rods back & =? 9 ! balls on ! ends ( ! collectors1 ! di/ance betwe5 ! balls on ! ends ( ! rods may be v>i$4 ,! sp>k dis*>ge f ! ma*9e1 :5 ! latt] is complet$1 takes place betwe5 ^! balls4 ,! ma*9e /ill rema9s to be fitt$ ) ! neutraliz]s & a set ( ,leyd5 j>s4 99,! ,neutraliz]s99 are illu/rat$ 9 ,figure #ad4 ,two are requir$4 ,!y consi/ ( a piece ( "o-eigh? in* brass rod1 six in*es long1 hav+ ! ends b5t ov] at "r angles s z to =m a %all[ ,u4 ,! di/ance betwe5 ! ends :5 b5t %\ld be ab\t ?ree & five-eights in*es4 ,a tuft ( t9sel %\ld be sold]$ to ! ends ( ea* ( ! neutraliz]s4 ,illu/ration3 ,,fig4 #aj4--,! ,collector ) ! ,dis*>ge ,rods1 etc1 9 position4 ,a is ! ,brass ,ball =m+ "o t]m9al ( ! gap across :i* ! sp>ks jump4 ,b is ano!r ,brass ,ball screw$ onto ! end ( ! ,collector ,rod & hav+ a hole 9 x1 ?r\gh :i* ! ,dis*>ge ,rod slips4 ,,cc are two ?read$ ,wa%]s us$ to clamp ! ,dis*>ge ,rod 9 place4 ,ea* neutraliz] rod is support$ by a h>d rubb] wa%] ?ree-qu>t]s ( an in* 9 diamet] & five-sixte5?s ( an in* ?ick4 ,9 ! c5tre ( ! wa%] a hole %\ld be drill$1 :i* w fit snugly onto ! rods ^u :i* ! plates are m\nt$ & revolve4 ,! neutraliz] rod passes ?r\gh a hole 9 ! upp] "p ( ! wa%] z %[n 9 ! illu/ration4 ,be=e ! neutraliz]s c be put into position x w be necess>y to pull out ! rods :i* support ! plates s t ! plates c be remov$4 ,! h>d rubb] wa%]s support+ ! neutraliz]s are !n slipp$ ov] ! rods s t "o w come betwe5 ea* support & plate :5 ! latt] is put back into position4 ,! rods %\ld be turn$ s t ! t9sel tufts t\* ! sectors4 ,! rubb] wa%]s %\ld fit snugly on ! rods s t ! neutraliz] w /ay 9 any position 9 :i* x is plac$4 ,! prop] position = ! front neutraliz] is a little less ?an half way betwe5 v]tical & horizontal z %[n 9 ,figure #a4 ,! neutraliz] beh9d ! re> plate %\ld be at "r angles to t 9 front4 ,illu/ration3 ,,fig4 #aa4--,%[+ h[ ,b9d+ ,po/s may be sub/itut$ = ,r\nd ,balls on ! ,collector ,rods4 ,! ma*9e is n[ all ready = op]ation4 ,9 ord] = x to op]ate satisfactorily x is necess>y = x to be w>m & dry4 ,x is1 !re=e1 a v good idea to ?or\ghly dry ! woodwork & give x a coat ( v>ni% or %ellac s t x _c absorb any moi/ure4 ,x may be necess>y to />t ! ma*9e by rubb+ a glass rod ) a piece ( flannel or silk & !n t\*+ ! rod to "s ( ! sectors4 ,! h&le ( ! ma*9e %\ld be turn$ f left to "r1 t is1 9 su* a direction t ! front plate revolves 9 ! same direction z ! h&s ( a clock4 ,if ! ma*9e is 9 prop] work+ ord] a /ream ( small sp>ks %\ld fl[ betwe5 ! sp>k balls on ! ends ( ! dis*>g] rods1 provid$ !y are n ov] a half in* ap>t1 :5 ! crank is turn$4 ,! sp>k c be int5sifi$ & l5g!n$ by fitt+ ! ma*9e ) two small ,leyd5 j>s4 99,! ,leyd5 ,j>s99 are made f small te/ tubes ?ree in*es long4 ,! inside ( ! tube %\ld be coat$ ) t9foil to )9 ab\t "o in* f ! top4 ,! outside ( ! tube %\ld be coat$ 9 ! same mann] = ! same di/ance4 ,! t9foil c be secur$ to ! glass ) %ellac4 ,! top ( ! ,leyd5 j>s is clos$ ) an ord9>y cork4 ,a piece ( heavy brass wire b5t into ! =m ( a hook %\ld pass ?r\gh ! cork & make connection ) ! t9foil on ! inside ( ! tube4 ,"o ,leyd5 ,j> %\ld be hung ov] ea* ( ! collector rods by means ( ! hook4 ,! t9foil coat+s on ! outside ( ! j>s %\ld be connect$ toge!r by a piece ( wire runn+ across f "o tube to ! o!r4 ,illu/ration3 ,,fig4 #ab4--;,details ( ! ,dis*>g] ,rods4 ,! ma*9e is n[ complete & ready = p]=m+ a numb] ( v int]e/+ exp]im5ts4 ,exp]im5ts ) ,/atic ,electrical ,app>atus4 99,a ,leyd5 ,j>99 is a v simple device = accumulat+ & /or+ /atic electricity4 ,x consi/s simply ( a wide m\!d j> or bottle coat$ ) t9foil "p way up on bo? ! outside & ! inside 9 exactly ! same mann] z ! small te/ tubes us$ on ! /atic ma*9e4 ,n all glass j>s are suitable = mak+ ,leyd5 ,j>s4 ,! quality ( ! glass v>ies consid]ably & "s w be f\nd f> sup]ior to ! re/4 ,! glass vessels us$ by *emi/s & call$ beak] glasses usually make excell5t ,leyd5 ,j>s4 ,x is n v difficult to make a good ,leyd5 ,j>4 ,aft] y h select$ ! j> or bottle y wi% to use1 clean & dry x v ?or\ghly4 ,!n give ! inside a ?or\gh bru%+ ov] ) %ellac4 ,cut a /rip ( t9foil :i* is long en\gh to g all ! way ar\nd ! inside ( ! j> & ab\t two-?irds its height4 ,be=e ! %ellac is ?or\ghly dry b is /ill /icky1 ins]t ! t9foil /rip c>efully into ! j> & press x smoo?ly aga9/ ! glass4 ,illu/ration3 ,,fig4 #ac4--,! ,support+ ,b> ^u :i* ! ,collector ,rods are m\nt$4 ,made ( h>d rubb] s z to be a p]fect ,insulator4 ,! outside ( ! j> %\ld also be giv5 a coat ( %ellac & cov]$ ) t9foil 9 exactly ! same mann]4 ,! t9foil on ! outside ( ! j> %\ld be ! same height z t on ! inside4 ,! bottom ( ! j> %\ld be coat$1 bo? inside & out by cutt+ two circul> pieces out ( ! t9foil & /ick+ !m on ) %ellac4 ,! j> %\ld be provid$ ) a wood5 cov] :i* w fit snugly into ! top4 ,! wood %\ld be dri$ & !n giv5 a coat ( %ellac s t x _c absorb any moi/ure4 ,illu/ration3 ,,fig4 #ad4--,! ,neutraliz]s4 ,two are requir$4 ,!y are b5t out ( ,brass ,rod & fitt$ ) a ,t9sel ,tuft at ea* end4 ,! c5tre piece ^u :i* ! ,rod is m\nt$ %\ld be ( ,h>d ,rubb]4 ,x may p]haps be well at ?is po9t to emphasize h[ highly important x is to always keep all /atic electrical app>atus ?or\ghly dry & to con/ruct x s t x w n collect or absorb any moi/ure4 ,a small hole %\ld be bor$ ?r\gh ! c5tre ( ! cov] s z to p]mit a brass rod to pass ?r\gh4 ,a piece ( spr+ wire b5t into a spiral %\ld be atta*$ to ! l[] end ( ! rod4 ,:5 ! cov] is 9 position1 ! spr+ wire %\ld make contact ) ! t9foil on ! inside ( ! j>4 ,x is a v good idea to fit ! top ( ! rod ) a small brass ball4 ,?is w prev5t ! electricity f leak+ f ! %>p corn]s on ! end ( ! rod4 ,/atic electricity leaks v easily f %>p corn]s or po9ts1 b does n escape s readily f r\nd corn]s or balls4 ,illu/ration3 ,,fig4 #ae4--;,details ( ! ,leyd5 ,j>s4 ,!y are simply small ,te/ ,tubes1 coat$ inside & outside ) t9foil = ab\t two-?irds _! height & fitt$ ) a ,brass ,rod connect$ ) ! inside coat+4 ,! ,leyd5 j> may be *>g$ ) electricity f ! /atic ma*9e by connect+ a wire f "o ( ! dis*>ge rods to ! outside t9foil coat+ on ! j>4 ,ano!r wire %\ld be connect$ f ! o!r dis*>ge rod to ! rod on ! j> :i* connects ) ! inside t9foil coat+4 ,turn+ ! h&le ( ! ma*9e rapidly = t5 or fifte5 seconds w *>ge ! j>4 ,disconnect ! wires z promptly z possible s t ! electricity 9 ! j> w n h a *ance to leak back into ! ma*9e4 ,be v c>eful :ile do+ ?is1 h[ev]1 because if y %\ld happ5 to t\* ! t9foil on ! outside ( ! j> & ! rod :i* connects ) ! inside coat+ at ! same "t y w get "o ( ! surprises ( y\r life4 ,illu/ration3 ,,fig4 #af4--;,a ,l>ge ,leyd5 ,j> = exp]im5tal purposes4 ,! %ock won't really hurt y any b x w be v uncom=table & some:at surpris+4 ,y c dis*>ge a ,leyd5 j> by br++ a piece ( wire :i* is connect$ to ! outside coat+1 ne> to ! knob on ! rod4 ,:5 ! wire is close to ! ball ! electricity w jump across ! space 9 ! %ape ( a snapp+ :ite sp>k4 ,! ,leyd5 j> c be us$ 9 connection ) a numb] ( exp]im5ts describ$ lat] on4 ,illu/ration3 ,,fig4 #ag4--,%[+ h[ to ,dis*>ge a ,leyd5 ,j> ) a curv$ piece ( /iff wire fitt$ to a ,wood5 ,h&le4 99,bottl$ ,lightn+499 ,a v pretty effect c be obta9$ by pass+ ! sp>k f a ,leyd5 j> or a /atic ma*9e ov] a lightn+ bo>d4 ,a lightn+ bo>d consi/s ( a pane ( glass hav+ a numb] ( small squ>es ( t9foil /uck on x s t :5 ! electrical dis*>ge is pass$ ov] x1 sp>ks take place betwe5 ! little t9foil squ>es & produce an effect some?+ l m9iature lightn+4 ,a lightn+ bo>d suitable = ! /atic ma*9e j describ$ may be made f a /rip ( ord9>y w9d[ glass ab\t n9e in*es long & two in*es wide4 ,clean ! glass ?or\ghly & !n give x a coat ( %ellac on "o side4 ,z soon z ! %ellac becomes /icky1 lay on a /rip ( t9foil ! same size z ! glass & rub x d[n smoo?ly4 ,:5 ! %ellac has ?or\ghly dri$ s t ! t9foil is /uck tightly to ! glass1 ! bo>d is ready to be cut up into squ>es4 ,?is c be be/ accompli%$ by means ( a %>p knife & a rul]4 ,use c>e 9 do+ ! "w s z n to te> ! t9foil & be sure t ! knife cuts all ! way ?r\gh to ! glass4 ,leave two solid /rips ( t9foil at ea* end to :i* to make connections4 ,illu/ration3 ,,fig4 #ah4--,! ,lightn+ ,bo>d is simply a ,/rip ( ,glass cov]$ ) small ,t9foil ,squ>es4 ,x may be insulat$ by m\nt+ on a ,bottle4 ,! two ,wires atta*$ to ! wide ,t9foil ,/rips at ! ends ( ! ,bo>d are = connection to ! ,/atic ,ma*9e or ,leyd5 ,j>4 ,! lightn+ bo>d %\ld be m\nt$ by cem5t+ x 9 a slot 9 a cork 9 a bottle s t ! glass bottle s]ves z an insulat$ support4 ,if "o ( ! t9foil /rips left solid at ! end ( ! bo>d is connect$ to "o ( ! dis*>ge rods on ! /atic ma*9e & ! o!r end is connect$ likewise to ! o!r dis*>ge rod innum]able little sp>ks w zig-zag betwe5 ! t9foil squ>es :5 ! ma*9e is set 9 op]ation4 ,! effect is q pretty if ! exp]im5t is p]=m$ 9 a d>k room4 ,! ,leyd5 j> c be *>g$ by ! /atic ma*9e & dis*>g$ ?r\gh ! lightn+ bo>d4 ,! sp>ks produc$ by ! ,leyd5 j> w be mu* m brilliant ?an ^? ( ! /atic ma*9e above4 ,a v pretty effect c be produc$ by arrang+ ! t9foil 9 ! =m ( a patt]n or design z = example t illu/rat$ 9 ,figure #ai4 ,a /rip ( glass ab\t ! same size z t us$ = ! lightn+ bo>d may be employ$4 ,! glass is coat$ ) %ellac & z soon z x becomes /icky1 small rectangul> pieces ( t9foil arrang$ 9 a zig-zag patt]n & hav+ small spaces betwe5 !m1 are /uck 9 position4 ,! end pieces are made l>g] ?an ! o!r /rips s z to af=d means = connect+ ! wires4 ,! /rip %\ld !n be insulat$ & m\nt$ by cem5t+ x 9 a slot 9 ! cork ( a glass bottle4 ,illu/ration3 ,,fig4 #ai4--;,a v pretty effect c be produc$ by arrang+ small t9foil /rips on ! ,glass 9 a ,patt]n4 ,ea* /rip %\ld be sep>at$ f ! o!r j f> en\gh = a ,sp>k to pass4 ,! app>atus %[n 9 ,figure #bj is made accord+ to ! same plan b ! glass 9 ?is case is 9 ! =m ( a squ>e in/ead ( a /rip4 ,! t9foil /rips are arrang$ 9 ! =m ( a sev5 po9t$ /> or any o!r patt]n :i* may be desirable4 ,! two l>ge /rips ,a & ,b are ! ones to :i* ! wires %\ld be connect$4 99,! ,electric ,p>asol99 is illu/rat$ 9 ,figure #ba4 ,x is made by pa/+ "s n>r[ /rips ( tissue pap]1 ab\t ?ree-sixte5?s ( an in* wide & ?ree or f\r in*es long1 to a small cork :i* has previ\sly be5 cov]$ ) t9foil4 ,! /rips c be made mo/ easily by cutt+ a small %eet ( tissue pap] into /rips l ! tee? ( a comb z %[n 9 ! upp] "r h& corn] ( ,figure #ba4 ,! t9foil cov]$ cork %\ld be m\nt$ on ! upp] end ( a /iff copp] or brass wire support$ 9 a bottle4 ,if ?is wire is !n connect$ to "o ( ! dis*>ge rods on ! /atic ma*9e & ! h& held to ! o!r1 ! pap] /rips w spread out l a p>asol or umbrella1 z soon z ! ma*9e is set 9 op]ation4 ,illu/ration3 ,,fig4 #bj4--;,a v pretty design made by arrang+ ! ,/rips 9 ! =m ( a ,sev5-po9t$ ,/>4 ,fl[]s1 initials or almo/ any patt]n may be made 9 ! same way4 ,a novel exp]im5t some:at simil> 9 pr9ciple to ! electric p>asol is t %[n 9 ,figure #bb4 ,?ree small pap] birds ab\t ! size ( t %[n at ! "r h& side ( ! illu/ration %\ld be cut out ( tissue pap] & ea* "o atta*$ to a piece ( cotton ?read ab\t six in*es long4 ,! ?reads are !n ti$ to "o end ( a ,t-%ap$ frame b5t out ( copp] wire & support$ on a bottle4 ,if ! wire frame is !n connect$ to "o ( ! dis*>ge rods & ! h& held to ! o!r :ile ! ma*9e is set 9 op]ation1 ! birds w rise 9 ! air & fly ar\nd z f> z ! ?reads w let !m4 ,illu/ration3 ,,fig4 #ba4--,! ,electric ,p>asol4 ,! upp] "r-h& corn] %[s a piece ( ,tissue ,pap] cut into ,/rips4 7#a7 ,is ! app>atus be=e ! ,tissue ,pap] is fa/5$ to ! ,cork4 7#b7 ,%[s ! complet$ ,p>asol & 7#c71 ! ,p>asol :5 connect$ to ! ma*9e & ! latt] is set 9 op]ation4 99,electric ,acrobats499 ,! app>atus %[n 9 ,figure #bc consi/s ( a circul> metal plate ab\t f\r in*es 9 diamet] susp5d$ by a wire f a wire ,t /uck 9 a cork 9 a bottle4 ,ano!r circul> metal plate ( ! same size is laid on ! table bel[ ! o!r4 ,! di/ance betwe5 ! two plates %\ld be ab\t "o in* or an in* & "o-half4 ,cut ?ree or f\r little figures1 ! same size z t %[n 9 ! upp] "r h& "p ( ! illu/ration1 out ( tissue pap] & lay !m on ! bottom plate4 ,illu/ration3 ,,fig4 #bb4--;,electric ,birds4 ,! ,birds are made ( ,tissue ,pap] & %\ld be ab\t ! size & %ape %[n 9 ! l[] "r-h& corn] ( ! illu/ration above4 ,! circul> metal plates may be made ( %eet t91 copp]1 brass or galvaniz$ iron4 ,ev5 c>dbo>d1 provid$ t x is cov]$ ) t9foil1 w s]ve4 ,! upp] plate %\ld be connect$ to "o dis*>ge rod on ! /atic ma*9e & ! l[] plate to ! o!r4 ,!n z soon z ! ma*9e is set 9 op]ation ! little pap] figures w beg9 to dance up & d[n1 /& on _! heads1 hang by "o foot or h&1 turn som]saults & p]=m all sorts ( /unts4 99,gunp[d]99 may be ignit$ by ! sp>k f a ,leyd5 j>4 ,a m9iature mort> may be made f a piece ( broom h&le ab\t an in* & "o-half 9 diamet] ) a hole "o in* deep 9 "o end z %[n by ,c ,figure #bd4 ,! mort> %\ld be fa/5$ to a small wood5 base :i* w support x 9 an incl9$ position z 9 ! illu/ration4 ,illu/ration3 ,,fig4 #bc4--;,electric ,acrobats4 ,! ,acrobats are made ( pap]4 ,! little figure 9 ! upp] "r-h& "p ( ! illu/ration is ! prop] size4 ,bore two small holes ?r\gh ! wall ( ! mort>1 ne> ! bottom & exactly opposite to ea* o!r ,ins]t two %ort pieces ( cop] wire1 ,w1 ,w1 9 ! holes & fa/5 !m tightly 9 position4 ,! ends ( ! wires %\ld be ab\t "o-eigh? ( an in* ap>t4 ,a small p9* ( gunp[d] is !n plac$ 9 ! bottom ( ! mort>4 ,*>ge ! ,leyd5 j> & !n dis*>ge x ?r\gh ! mort> by connect+ x to ! two wires ,w1 ,w4 ,z soon z ! sp>k passes1 ! p[d] w explode4 ,an exp]im5t su* z ?is %\ld be p]=m$ cauti\sly & ! face & h&s %\ld be kept away f ! p[d]4 ,d n put m ?an a p9* ( p[d] 9 ! mort> at a "t & by all means keep ! res]ve supply out ( ! way s t !re w be no dang] ( explod+ x by accid5t4 99,an ,electric ,:irligig99 is an int]e/+ piece ( app>atus :i* may be built by foll[+ ! sugge/ions conta9$ 9 ,figure #be4 ,illu/ration3 ,,fig4 #bd4--,! ,electric ,mort>4 ,c is ! ,mort>1 ,p ! ,p[d]1 ,b a ,small ,ball & ,w ,w ! two ,wires betwe5 :i* ! ,sp>k ignit+ ! p[d] takes place4 ,m\nt f\r pieces ( d[el ab\t ?ree in*es long at ! corn]s ( a wood5 base ab\t eight in*es long & two in*es wide s t !y =m f\r v]tical po/s z %[n by ,a1 ,b1 ,c1 ,d4 ,! d[els1 z well z ! wood5 base %\ld be c>efully dri$ & %ellac$ s t !y w n absorb any moi/ure4 ,/ret* two pieces ( /raight /iff wire betwe5 ! po/s ,a ,c & ,b ,d1 ne> ! top4 ,! wires %\ld be p]fectly /raight & level4 ,! :irligig itself is made by pass+ a sew+ ne$le ?r\gh ! axis ( a small cork4 ,f\r small wires hav+ ! ends b5t ov] at "r angles %\ld !n be /uck 9 ! cork z %[n 9 ! upp] left h& "p ( ,figure #be4 ,all ( ! wires %\ld po9t 9 ! same direction4 ,illu/ration3 ,,fig4 #be4--;,an ,electric ,:irligig4 ,! f\r wires %\ld all be ! same l5g? s t ! :irligig is p]fectly balanc$4 ,! cork is !n cov]$ ) t9foil s t !re w be an electrical connection betwe5 ! f\r small wires & ! ne$le =m+ ! %aft4 ,! two wires ,a ,c & ,b ,d are connect$ toge!r by a wire ,a ,b & a piece ( flexible wire l$ to ! ,wim%ur/ ma*9e4 ,! opposite side ( ! ,wim%ur/ ma*9e is !n gr\nd$ or t\*$ ) ! h&4 ,if ! :irligig is laid on ! wires ,a ,c & ,b ,d z %[n 9 ! illu/ration & x is p]fectly balanc$ x w comm5ce to revolve & roll along ! wires j z soon z ! ,wim%ur/ ma*9e is set 9 op]ation4 ,x is ! escape ( ! electricity f ! po9ts ( ! f\r wires on ! :irligig :i* causes ?is4 ,o!r int]e/+ exp]im5ts 9 /atic electricity may be p]=m$ ) ! aid ( a ,wim%ur/ ma*9e & ! exp]im5t] :o is suffici5tly int]e/$ to cont9ue f>!r is ref]r$ to any good book on physics or "s su* volume z ,! ,boy ,electrician4 ,,*apt] ,,ii4 ,,cells ,,& ,,batt]ies4 ,s\rces ( ,curr5t4 ,"o ( ! *ief difficulties ( ! av]age "y exp]im5t] is to secure a satisfactory s\rce ( curr5t = op]at+ 8 app>atus4 ,!re are ?ree means at 8 disposal & he may draw 8 electricity f #a4 ,a p[] or light+ circuit2 #b4 ,a dynamo2 #c4 ,batt]ies4 ,illu/ration3 ,,fig4 #bf4--;,a ,voltaic ,cell4 ,a ,voltaic ,cell consi/s ( a ,/rip ( ,copp] & a ,/rip ( ,z9c imm]s$ 9 a dilute solution ( ,sulphuric ,acid4 ,only ^? :o are s =tunate z to live 9 a h\se wir$ = light & p[] s]vice & suppli$ f ! /reet ma9s1 are likely to be able to utilize ! fir/ nam$4 ,^? exp]im5t]s :o live 9 t[ns :]e !re are no comm]cial p[] wires or ^: homes are n wir$ = su* s]vice w h to !re=e dep5d ^u a dynamo or a batt]y4 ,a dynamo is a v satisfactory s\rce ( curr5t1 provid$ "s sort ( p[]1 su* z a w9dmill1 wat] motor or small eng9e is available = driv+ x4 ,a h& dynamo is unsatisfactory = "s purposes because ! exp]im5t] is usually unable to drive ! dynamo & att5d to o!r "w at ! same "t4 ,batt]ies are ! mo/ exp5sive s\rce ( curr5t b = _m reasons1 z expla9$ above1 are all t is available to ! av]age exp]im5t]4 ,!re are two classes ( batt]ies1 kn[n z #a4 ,prim>y batt]ies2 #b4 ,second>y or /orage batt]ies4 99,prim>y ,batt]ies99 are ^? :i* g5]ate _! own curr5t by ! action ( "s *emical su* z1 = example1 an acid ^u a metal4 99,second>y ,batt]ies99 d]ive _! curr5t f a dynamo or o!r s\rce ( electricity & /ore x away 9 ! =m ( 99,*emical en]gy99 until x is us$ up4 ,a /orage batt]y might be lik5$ to a pail1 :i* c be c>ri$ to a dynamo & fill$ full ( electricity4 ,^? :o possess a /orage batt]y c re*>ge x !mselves f ! #aaj-volt light+ or p[] circuit1 f a dynamo or by tak+ x to an automobile g>age :]e re*>g+ is done4 ,homemade batt]ies are n z practical z ^? :i* c be pur*as$ ready made1 b ! k & exp]i5ce ga9$ 9 mak+ y\r own are s valuable t e exp]im5t] is urg$ to />t 9 ?is way4 ,v>i\s mat]ials su* z z9c1 copp]1 c>bon1 etc41 c be us$ to make "s v int]e/+ & valuable batt]ies4 ,"o ( ! mo/ common mi/akes made 9 ref]5ce to cells & batt]s is 9 call+ a s+le cell a 99batt]y994 ,"o cell is a cell4 ,m ?an "o cell connect$ toge!r is a 99batt]y ( cells99 or simply a 99batt]y994 ,! ,voltaic ,cell4 ,! fir/ practical cell 0 inv5t$ 9 #aghf by an ,italian pr(essor nam$ ,volta & x is1 !re=e usually call$ ! ,voltaic cell4 ,a ,voltaic cell may be easily made by ! exp]im5t]1 by plac+ "s wat]1 mix$ ) sulphuric acid1 9 a glass tumbl] or a jelly j> & !n imm]s+ !re9 a /rip ( z9c & a /rip ( copp]1 ea* ab\t f\r in*es long & "o in* wide4 ,! /rips mu/ be kept sep>ate f "o ano!r & %\ld be scrap$ clean & bright be=e !y are plac$ 9 ! solution4 ,a copp] wire is fa/5$ to ! top ( ea* "o ( ! /rips4 ,! acid solution %\ld be compos$ ( "o "p ( acid1 mix$ ) t5 p>ts ( wat]4 ,:5 mix+ acid & wat]1 always rememb] to p\r ! acid into ! wat] & nev] p\r wat] into acid4 ,o!rwise ! solution w sudd5ly become v hot & is liable to crack ! j>4 ,acid %\ld always be mix$ 9 a glass or e>!nw>e vessel & nev] 9 any sort ( a wood5 or metal receptacle1 because x w attack & dissolve metals & wood4 ,z soon z ! acid has be5 prep>$ = ! ,voltaic cell fill a tumbl] ab\t ?ree qu>t]s full & !n imm]se ! z9c & copp] /rips !re94 ,z soon z ! /rips are 9 ! acid1 bubbles w comm5ce to rise f ! z9c4 ,^! bubbles are a gas call$ hydrog5 & are evid5ce ( a *emical action :i* takes place 9 a batt]y4 ,! z9c is be+ dissolv$ by ! acid & dur+ ! process1 sets free hydrog5 gas4 ,x w probably be notic$ t v few bubbles arise f ! copp] plate & t !re seems to be little *emical action !re4 ,x w also be notic$ t if ! two wires connect$ to ! /rips are br\ght toge!r ! bubbles w arise f ! z9c mu* fa/] ?an be=e4 ,t is because1 :5 ! wires are connect$ toge!r1 a complete electrical circuit is =m$3 ,! z9c is really be+ oxidiz$ or sl[ly burn$4 ,if z9c is burn$ 9 ! op5 air or 9 a fire x w give out its en]gy 9 ! =m ( heat b :5 x is burn$ 9 an acid solution 9 ! pres5ce ( ano!r metal x gives out its en]gy 9 ! =m ( electricity4 ,! z9c /rip 9 a ,voltaic batt]y is kn[n z ! 99negative99 pole or ca?ode1 & ! copp] /rip1 z ! positive pole or anode4 ,:5 ! electrical circuit is complet$ by t\*+ ! two wires connect$ to ! poles toge!r1 ! curr5t is suppos$ to fl[ f ! positive pole ?r\gh ! wires & back into ! solution ?r\gh ! negative pole4 ,if ! two wires1 in/ead ( be+ connect$ toge!r1 are connect$ to an electrical in/rum5t call$ a voltmet] ! ne$le or po9t] on ! met] w sw+ ov] & po9t to ab\t "o volt4 99,a ,voltmet]99 is an in/rum5t = measur+ electrical pressure or 99pot5tial994 ,! pressure ( an electric curr5t is measur$ 9 99volts99 j z ! pressure ( wat] may be measur$ 9 99p\nds994 ,if ! copp] /rip is lift$ out ( ! solution & a c>bon plate or rod also hav+ a wire atta*$ is sub/itut$ 9 its place x w be f\nd t ! voltage or pot5tial has increas$ to "o & "o-half volts4 ,z9c & c>bon are said to h a great] pot5tial diff]5ce ?an z9c & copp] & inasmu* z x is usually desirable = a batt]y to h ! greate/ pot5tial diff]5ce possible1 z9c & c>bon are employ$ 9 ! batt]ies ( to-day in/ead ( z9c & copp]4 ,if ! wires are !n disconnect$ f ! voltmet] & connect$ to an electrical in/rum5t call$ an 99ammet]991 ! ne$le or po9t] w probably sw+ ov] until x indicates a curr5t ( p]haps t5 amp]es4 ,an 99ammet]99 is an in/rum5t = measur+ ! volume ( an electric curr5t4 ,an 99amp]e99 is a unit ( curr5t & is us$ to designate ! rate ( fl[ j z feet p] second are us$ to d5ote rate ( fl[ 9 ! case ( wat] 9 a pipe4 ,if ! met] is all[$ to rema9 connect$ to ! cell = a %ort "t x w be notic$ t ! po9t] w comm5ce to sl[ly drop back t[>ds z]o4 ,! cell is !n becom+ 99pol>iz$991 :i* is to say t small bubbles ( hydrog5 :i* are lib]at$ by ! *emical action1 collect on ! c>bon & cause ! /r5g? ( ! batt]y to fall (f4 ,if ! batt]y is agitat$ or ! c>bon is lift$ out & scrap$ x w be f\nd t ! curr5t w imm$iately rise aga9 to its fir/ /r5g?4 ,x w\ld be a nuisance if x 7 cont9ually necess>y to scrape ! c>bon or %ake ! batt]y s z to avoid 99pol>ization99 & s ano!r means is employ$ to secure ! desir$ result4 ,?is is accompli%$ by introduc+ c]ta9 *emicals into ! solution :i* w give =? 99oxyg5994 ,:5 oxyg5 & hydrog5 meet "u prop] conditions !y comb9e & =m ord9>y 99wat]994 99,bi*romate ( pota%99 or z x is also (t5 call$ 99potassium bi*romate99 is ! *emical mo/ commonly employ$ = ?is purpose4 ,illu/ration3 ,,fig4 #bg4--,ord9>y ,jelly ,glasses1 ,tumbl]s1 ,fruit ,j>s1 etc1 make good ,j>s = small cells by cutt+ (f ! tops4 ,homemade ,batt]ies4 99,! mat]ials99 requir$ = mak+ batt]ies1 suitable z a s\rce ( curr5t = ! exp]im5t]1 w n be f\nd exp5sive 9 mo/ cases4 99,c>bon rods99 & 99plates99 may be pur*as$ f an electrical supply h\se b !y c also be easily & *eaply obta9$ f old dry cells4 ,dry cells may be split op5 ) a cold *isel & a hamm]4 ,c>e %\ld be ex]cis$ n to break ! c>bon 9 remov+ x4 ,! r\nd c>bon rods us$ 9 arc lamps may be us$ = mak+ batt]ies provid$ t if !y are copp] plat$1 ! copp] is fir/ remov$ by imm]s+ ! rod 9 a ba? ( nitric acid4 ,if ?is precaution is n tak5 !re w be a local action set up betwe5 ! copp] & ! c>bon & ! batt]y w n be z effici5t z x w be if ! copp] is remov$4 ,c>bon rods & plates are easily drill$ ) an ord9>y h& drill4 ,c>bon is q brittle & breaks easily1 !re=e only v light pressure %\ld be us$4 ,:ile z9c rods & plates may also be pur*as$ !y are easily made by ! exp]im5t] :o possesses a little +5uity4 ,! melt+ po9t ( z9c is q l[4 ,x c be melt$ 9 a small iron pot & ca/ into ! =m ( rods or plates 9 pla/]-(-,p>is m\lds4 ,plates may also be cut out ( heavy %eet z9c4 ,illu/ration3 ,,fig4 #bh4--;,a ,simple ,home-made ,cell4 ,ord9>y jelly-glasses1 tumbl]s1 fruit j>s1 etc41 make good j>s = small cells4 ,! tops ( fruit j>s & batt]ies c be cut (f s z to make ! op5+ l>g]4 ,! cutt+ c be done ) an ord9>y glass cutt] or by fill+ a scrat* completely ar\nd ! j> or bottle1 at ! place x is desir$ to cut x (f1 ) a ?ree corn]$ file4 ,if a hot pok] or wire is !n held aga9/ ! scrat* x w comm5ce to crack along ! l9e & foll[ ! hot pok] z x is drawn ar\nd4 ,illu/ration3 ,,fig4 #bi4--;,a ,home-made ,batt]y hav+ two ,c>bon ,plates ) a ,z9c ,rod betwe54 ,figure #bh %[s a simple arrangem5t consi/+ ( a c>bon & a z9c plate m\nt$ ^u a wood5 /rip4 ,! /rip is us$ to support ! plates & re/s across ! top ( ! j> s t ! plates hang bel[ 9 ! solution4 ,mo/ *emicals attack wood & = t reason x is well to dip ! /rip 9 "s hot p>aff94 ,! c>bon & z9c plates are fa/5$ on opposite sides ( ! wood5 /rip by means ( a r\nd head$ screw & a wa%]4 ,a wire lead %\ld be plac$ "u ! wa%] on ea* plate4 ,if ! screw & wa%] are !n sme>$ ) "s hot p>aff9 or vasel9e !y w be protect$ f corrosion4 ,c>e %\ld be us$ s t ! two screws employ$ to fa/5 ! plates to ! /rip d n t\* ea* o!r 9 ! wood4 ,if !y %\ld1 ! batt]y w be %ort circuit$ & ! curr5t w fl[ ?r\gh ! screws in/ead ( ! wires4 ,figure #bi %[s an arrangem5t consi/+ ( two c>bon plates m\nt$ ^u a wood5 /rip4 ,! z9c elem5t consi/s ( a rod set 9 a :ole 9 ! /rip betwe5 ! two c>bon plates4 ,x w be f\nd t two c>bon plates w =m a bett] cell ?an "o ) only "o plate or rod4 ,! arrangem5t illu/rat$ 9 ,figure #cj %[s two c>bon rods & "o z9c rod clamp$ betwe5 two wood5 /rips4 ,! z9c rod is plac$ 9 ! c5t] & ! c>bons to ei!r side4 ,illu/ration3 ,,fig4 #cj4--,! ,elem5ts = a ,simple ,home-made ,cell compos$ ( two ,c>bon ,rods & "o ,z9c ,rod clamp$ betwe5 two ,wood5 ,/rips4 ,! wood5 /rips are cut away a bit at ! po9ts :]e !y clamp ! rods s z to =m sort ( a groove into :i* ! rods fit )\t slipp+ or twi/+4 ,! /rips are drawn toge!r tightly at ! ends by two wood screws4 ,:5 m ?an "o c>bon rod or plate is us$ 9 a cell1 ! c>bons %\ld all be connect$ toge!r s z to =m a s+le unit4 ,! draw+ 9 ,figure #cj %[s a wire twi/$ ar\nd ! c>bons s z to connect !m toge!r b x w\ld be a f> bett] connection if ! wire 0 clamp$ betwe5 ! c>bons & ! wood s t x is held firmly4 ,f\r c>bon rods may be utiliz$ by foll[+ ! sugge/ion %[n by ! draw+ 9 ,figure #ca4 ,?is consi/s ( a squ>e piece ( wood ab\t #d x #d in*es & "o-half ( an in* ?ick4 ,illu/ration3 ,,fig4 #ca4--;,f\r ,c>bon ,rods & "o ,z9c ,rod arrang$ to =m ! ,elem5ts ( a ,cell4 ,a z9c rod is set 9 a hole 9 ! c5t]4 ,f\r c>bon rods are set 9 a circle ar\nd ! z9c & held 9 place by screws4 ,all ! c>bon rods %\ld be connect$ toge!r4 ,! wood5 top n only s]ves to support ! c>bon & z9c rods1 b w also act z a cov] = ! cell & prev5t ! solution f evaporat+4 ,batt]y ,solutions or ,electrolytes4 ,x has already be5 %[n h[ cells become pol>iz$ :5 ! solution consi/s simply ( sulphuric acid & wat]4 ,an ord9>y acid solution also has ! fur!r disadvantage t ! z9c elem5t is cont9ually consum$ by ! acid :5 x is 9 ! solution1 reg>dless ( :e!r curr5t is be+ drawn f ! cell or n4 ,x is ( c\rse consum$ m rapidly :5 ! circuit is complete & curr5t is fl[+ ?an :5 x is n1 b ! action is /ill nev]!less suffici5tly rapid to entirely consume ! z9c ev5 9 ! latt] case 9 a v %ort "t4 ,if an ord9>y acid solution is us$ !re=e z ! liquid or 99electrolyte991 z x is te*nically t]m$1 x is always necess>y to lift ! elem5ts out ( _! solutions :5ev] ! cells are n 9 use4 ,!y %\ld be lift$ out & c>efully wa%$ s z to remove all traces ( acid4 ,illu/ration3 ,,fig4 #cb4--;,a ,batt]y ( ,?ree ,cells arrang$ s t !y c all be lift$ out ( ! solution at once4 ,a mild] *emical :i* does n attack ! z9c s rapidly z an acid is (t5 us$ :]ev] a batt]y is to be employ$ = r++ bells1 op]at+ s\nd]s1 telephon+1 etc41 & only a small am\nt is requir$4 ,sal-ammoniac or *loride ( ammonium1 z x is also call$1 is a good *emical = ?is purpose4 ,x is v *eap & only requires to be dissolv$ 9 wat]4 ,a good /rong solution %\ld be made & an elem5t consi/+ ( sev]al c>bons & "o z9c su* z ^? %[n 9 ,figures #bi1 #cj & #ca us$4 ,su* a cell w give ab\t #a4e volts & #c or #d amp]es4 ,if ! curr5t is drawn f ! batt]y cont9u\sly or too rapidly1 x w also 99pol>ize99 & ! curr5t w beg9 to fall (f4 ,! advantage ( a sal-ammoniac cell is t ! elem5ts may be left 9 ! solution :5 ! cell is n 9 use1 )\t appreciable wa/e ( ! z9c4 ,a v p[]ful cell ( ! non-pol>iz+ type capable ( deliv]+ a heavy curr5t & hav+ an ,e4 ,m4 ,f4 ( two volts c be made by add+ "s potassium bi*romate to a sulphuric acid solution4 ,an electrolyte ( ?is sort may be prep>$ by dissolv+ f\r ounces ( bi*romate ( pota% 9 sixte5 ounces ( wat]4 ,add to ?is1 f\r ounces ( sulphuric acid4 ,! acid %\ld be add$ sl[ly & ! solution /irr$ at ! same "t4 ,?is solution w be f\nd an excell5t "o to use ) cells hav+ c>bon & z9c elem5ts4 ,! curr5t & voltage are mu* high] ?an ^? ( an ord9>y acid solution4 ,?is type ( cell also has ! disadvantage t ! z9cs wa/e away rapidly :5 9 ! solution1 reg>dless ( :e!r curr5t is be+ drawn or n4 ,?is c be p>tly ov]come by 99amalgamat+99 ! z9cs ) m]cury4 ,9 ord] to amalgamate y\r batt]y z9cs1 procure a little 99m]curic nitrate99 f a druggi/ or *emical h\se4 ,dissolve ! m]curic nitrate 9 a small am\nt ( wat] & !n rub ! z9cs ) a wad ( cotton or clo? :i* has be5 dipp$ 9 ! m]curic nitrate solution4 ,! arrangem5t %[n 9 ,figure #cb is a v conv5i5t "o to foll[ 9 arrang+ a batt]y ( ?ree or m cells4 ,! elem5ts ( ?ree cells are all m\nt$ ^u a /rip ( p>aff9$ wood & connect$ 9 s]ies4 ,! ?ree batt]y j>s are plac$ 9 a r[ s t ea* pair ( elem5ts w dip into _! prop] j> :5 ! /rip is laid across ! tops4 ,su* an arrangem5t is n only m compact ?an "o hav+ ! elem5ts compos+ ea* cell m\nt$ ^u sep>ate /rips1 b w be f\nd v conv5i5t :5 an electrolyte compos$ ( bi*romate ( pota% & acid is us$1 because all ! elem5ts may !n be rais$ out ( ! solutions at ! same "t4 ,x is possible to place ! j>s 9 a frame & arrange a w9dlass fitt$ ) a crank s t ! elem5ts may be easily rais$ or l[]$ f & to ! solution4 ,su* an arrangem5t is call$ a plunge batt]y4 ,connect+ ,cells4 ,cells may be connect$ ei!r 9 99s]ies991 9 99multiple991 or 9 99s]ies-multiple991 dep5d+ ^u ! numb] ( cells to be us$ & ! amp]age & voltage desir$4 ,illu/ration3 ,,fig4 #cc4--,%[+ h[ ,cells are arrang$ :5 !y are connect$ 9 ,s]ies4 ,! ,voltage ( ,six ,dry ,cells connect$ 9 s]ies z above w\ld be approximately #f x #a4e or #i ,volts4 ,cells are 9 s]ies :5 !y are connect$ ) a wire lead+ f ! negative pole ( "o ( ! positive pole ( ano!r1 s t ! curr5t fl[s ?r\gh ea* "o 9 turn4 ,figure #cc %[s six cells connect$ 9 s]ies4 ,cells are plac$ 9 s]ies :5 voltage is ! mo/ important factor4 ,! total voltage ( ! batt]y is !n equal to ! sum ( ! voltages ( ! cells4 ,= example1 ! voltage ( ! ord9>y dry cell is ab\t #a4e & !re=e if f\r dry cells are connect$ 9 s]ies ! total voltage ( ! batt]y w be six4 ,if six dry cells are connect$ 9 s]ies ! voltage at ! t]m9als w be ab\t n9e4 ,:5 a heavy amp]age is desir$1 cells are connect$ 9 multiple4 ,figure #cd %[s six cells connect$ 9 multiple4 ,x w be notic$ t all ! negative poles are connect$ toge!r to =m "o t]m9al1 :ile all ! positive poles =m ano!r4 ,! amp]age ( ! av]age dry cell is ab\t #bj4 ,! amp]age ( a batt]y ( cells connect$ 9 multiple is equal to ! sum ( ! amp]ages ( ! sep>ate cells4 ,! amp]age ( f\r cells connect$ 9 multiple w be ab\t #hj & ab\t #abj 9 ! case ( six cells4 ,illu/ration3 ,,fig4 #cd4--,%[+ ,six ,dry ,cells connect$ 9 ,multiple4 ,! ,voltage ( su* an arrangem5t w\ld only be #a4e1 b ! ,amp]age available w\ld be six times t possible f ,cells connect$ z 9 ,figure #cc4 ,! life ( ! av]age dry cell is ab\t tw5ty amp]e h\rs "u normal conditions4 ,if h[ev] ! cell is dis*>g$ at a high rate1 say = in/ance1 five amp]es1 x w be f\nd t ! life is less ?an tw5ty amp]e h\rs4 ,on ! o!r h&1 if ! dis*>ge rate is v l[1 z = example1 "o-qu>t] ( an amp]e1 ! capacity ( ! cell w be great]4 ,9 ord] to get ! mo/ economical s]vice f a batt]y x is !re=e advisable to light5 ! load z f> z possible1 & cells are consequ5tly (t5 connect$ 9 99s]ies-multiple99 ) t result 9 view4 ,9 a case1 = illu/ration1 :]e x might be desirable to secure a curr5t #d #a_/b volts & five amp]es f dry cells1 ! s]ies-multiple arrangem5t c\ld be recomm5d$4 ,?ree dry cells connect$ 9 s]ies w furni% #d #a_/b volts & five amp]es1 b by us+ two sets z 9 ,figure #ce1 ! load is divid$ betwe5 !m & ea* set w only h to furni% amp]es to ! circuit4 99,two sets ( cells us$ 9 s]ies-multiple w !re=e la/ m ?an twice z long z ei!r set w\ld alone499 ,! s]ies-multiple arrangem5t is recomm5d$ :]e cells are to be us$ = op]at+ toy tra9s1 induction coils1 motors1 etc41 z be+ ! mo/ economical4 ,always be sure to use l>ge wire 9 connect+ cells4 ,f9e wire (f]s consid]able resi/ance to ! electrical curr5t & ! full b5efit ( ! batt]ies _c be secur$ :5 x is us$4 ,illu/ration3 ,,fig4 #ce4--,%[+ h[ to connect a ,batt]y ( ,cells 9 ,s]ies-,multiple4 ,use c>e to scrape all connections s t !y are clean & bright4 ,tight5 ! b9d+ po/s ) a pair ( pli]s s t !re is no *ance ( _! becom+ loose4 ,ano!r wise precaution is to always arrange batt]ies s t !re is a small space betwe5 two cells & no likelihood ( any ( ! wires or b9d+ po/s com+ into contact ) "o ano!r s z to =m a %ort circuit4 ,aft] ! connections h be5 c>efully made a little vasel9e sme>$ ov] !m w prev5t corrosion4 ,illu/ration3 ,,fig4 #cf4--;,batt]y ,connectors l t %[n above c be obta9$ = #a #a_/b c5ts ea* & w be f\nd to be v h&y4 ,/orage or ,second>y ,cells4 ,/orage or second>y cells 7also sometimes call$ accumulators71 diff]s f prim>y cells 9 t !y w n give =? an electric curr5t until !y h be5 99*>g$99 by pass+ an electric curr5t ?r\gh !m4 ,illu/ration3 ,,fig4 #cg4--;,a ,simple ,exp]im5tal ,/orage ,batt]y consi/+ ( two ,lead ,plates imm]s$ 9 ,dilute ,sulphuric ,acid4 ,! ,/orage ,cell is !re=e a v conv5i5t means ( tak+ electric en]gy at "o "t or place & /or+ x up = future use4 ,f ?is x mu/ n be impli$ t electricity is actually /or$ 9 su* a batt]y4 ,! en]gy ( ! electric curr5t is really *ang$ into *emical en]gy & ?is en]gy produces electricity :5 ! cell is aga9 dis*>g$4 ,! sup]iority ( ! /orage cell ov] any o!r =m ( batt]y is univ]sally recogniz$4 ,! dry cell has an ,e4 ,m4 ,f4 ( only #a4e volts & det]iorates rapidly ) age4 ,! ,e4 ,m4 ,f4 ( a /orage cell is #b volts1 or #cc #a_/c p] c5t high]4 ,/orage cells w op]ate almo/ any electrical device ) increas$ p[] ov] any o!r =m ( batt]y4 ,a wireless set w s5d f>!r1 lamps w turn /eadi] & a motor w give m p[]4 ,illu/ration3 ,,fig4 #ch4--,%[+ h[ to *>ge a ,simple ,/orage ,cell compos$ ( two ,lead ,plates imm]s$ 9 ,sulphuric ,acid by connect+ x to two ,bi*romate ( ,pota% ,cells4 ,if prop]ly c>$ =1 a /orage cell w la/ indef9itely4 ,x may be re*>g$ an unlimit$ numb] ( times & is exactly z good z new ea* "t4 ,a dry cell mu/ be ?r[n away :5 dis*>g$4 ,/orage cells are rat$ by _! output 9 99,amp]e ,h\rs499 ,an 99,amp]e ,h\r99 is ! am\nt ( curr5t repres5t$ by "o amp]e fl[+ = "o h\r4 ,a #aj amp]e h\r cell w give #b amp]es = five h\rs1 #a amp]e = #aj h\rs1 #a_/b amp]e = #bj h\rs1 etc4 ,! amp]e h\r capacity ( a cell divid$ by ! am\nt ( curr5t be+ us$ w det]m9e h[ long t curr5t c be drawn be=e re*>g+ is necess>y4 ,/orage cells may be re*>g$ f any s\rce ( 99direct99 curr5t1 t is1 f ! light+ circuit1 9 s]ies ) a lamp1 f a small %unt w\nd dynamo1 f dry cells or o!r prim>y batt]ies1 or f alt]nat+ curr5t by us+ a 99,rectifi]994 ,an ,exp]im5tal ,/orage ,cell4 ,/orage cells consi/ ( lead plates imm]s$ 9 an electrolyte ( dilute sulphuric acid4 ,cut two /rips1 "o in* wide & five in*es long1 out ( %eet lead ab\t "o-eigh? ( an in* ?ick4 ,atta* a wire to ea* "o ( ! plates & !n imm]se !m 9 a j> full ( 99electrolyte99 compos$ (3 #a4 ,t5 p>ts ( wat]4 #b4 ,"o "p ( sulphuric acid4 ,connect ! wire lead+ f ! plates to a voltmet] & y w notice t ! po9t] w n move away f z]o4 ,disconnect ! wires & m>k "o plate z ! 99positive991 by means ( a little cross2 m>k ! o!r plate 99negative991 ) a /raight l9e4 ,connect two good bi*romate cells 9 s]ies & lead ! positive t]m9al to ! lead plate m>k$ ) a cross4 ,connect ! negative pole ( ! batt]y to ! o!r lead plate4 ,bubbles ( gas w imm$iately beg9 to arise f ! lead plates4 ,let ! batt]ies rema9 connect$ = ab\t five m9utes & !n remove !m4 ,if y !n connect ! two lead plates to ! voltmet] aga9 y w f9d t ! ne$le n[ sw+s ne>ly to two volts4 ,y w also f9d t y\r /orage cell1 = ! two lead plates are n[ a /orage cell1 w also r+ a bell or run a small motor = a few seconds4 ,! two lead plates became 99*>g$99 :5 ! curr5t f ! bi*romate cells 0 pass$ ?r\gh !m4 ,?is little exp]im5t illu/rates ! pr9ciple ( ! /orage cell v well4 ,a /orage cell made ( lead plates 9 ! mann] j describ$ w\ld n possess suffici5t capacity to make x wor? :ile z a practical cell4 ,x has be5 f\nd t if in/ead ( a solid flat plate1 a framework or grid is us$1 consi/+ ( a set ( b>s cross+ "o ano!r at "r angles1 leav+ spaces betwe51 :i* are fill$ ) a pa/e made ( lead oxides1 !re w be a consid]able ga9 9 ! capacity ( ! cell4 ,a ,homemade ,/orage ,cell4 ,! /orage cell illu/rat$ 9 ! accompany+ illu/rations is v simple to make & a batt]y ( !m capable ( deliv]+ six or eight volts w prove a v conv5i5t s\rce ( curr5t = p]=m+ all sorts ( electrical exp]im5ts4 ,illu/ration3 ,,fig4 #ci4--,%[+ h[ ! ,plates = a ,/orage ,cell may be made f ,%eet ,lead by bor+ x full ( holes & fill+ ) pa/e4 ,! plates are cut f %eet lead f "o-qu>t] to five-sixte5?s ( an in* ?ick4 ,! height & wid? w dep5d ^u ! size ( ! j>s us$4 ,!re are sev]al sizes ( rectangul> glass /orage cell j>s on ! m>ket1 & if ! plates are made ab\t ?ree in*es wide & ?ree & "o-half in*es high1 !y w fit ! smalle/ size ( j>4 ,a lug ab\t "o in* & "o-half long & ?ree-qu>t]s ( an in* wide is left project+ at ! top4 ,?ree plates are us$ 9 ea* cell4 ,ea* cell w h an ,e4 ,m4 ,f4 ( two volts :5 fully *>g$4 ,9 ord] !re=e to h a batt]y capable ( deliv]+ six volts1 ?ree cells w be necess>y4 ,n9e plates w be requir$ = ?ree cells4 ,! body ( ! plates %\ld !n be drill$ full ( holes ab\t "o-eigh? ( an in* 9 diamet] z %[n by ,b 9 ,figure #ci4 ,! plates are n[ ready = pa/+4 ,select ?ree ( ! plates & m>k !m ) a small cross4 ,^! are to be 99positive99 plates :5 f9i%$4 ,! pa/e = ^! plates is made by mix+ r$ lead ) dilut$ sulphuric acid4 ,! pa/e %\ld =m a good /iff mixture4 ,lay ! ?ree plates ^u a smoo? bo>d & press ! pa/e c>efully into ! holes ) a flat /ick4 ,!y are !n laid aside to dry & h>d54 ,illu/ration3 ,,fig4 #dj4--;,a set ( ?ree ,plates compos$ ( ,"o ,positive & ,?ree ,negatives assembl$ to =m a ,cell4 ,! six rema9+ plates are to be 99negatives99 :5 f9i%$ & !y are pa/$ 9 id5tically ! same mann] z ! positives except t ! pa/e is made ( a mixture ( yell[ lead & dilute sulphuric acid in/ead ( r$ lead4 ,a pa/$ plate is %[n at ! "r 9 ,figure #ci4 ,cut six rectangul> pieces1 ?ree by ?ree & "o-half in*es1 ( heavy blott+ pap] or ?9 :itewood4 ,! ?9 wood us$ 9 ! con/ruction ( fruit baskets may be us$ = ?is purpose4 ,^! rectangles are to be us$ z sep>ators betwe5 ! plates4 ,illu/ration3 ,,fig4 #da4--;,glass & ,rubb] ,/orage ,cell ,j>s :i* are on ! m>ket = ! ,electrical ,exp]im5t] & may be pur*as$ v reasonably4 ,! plates %\ld !n be assembl$ 9 gr\ps ( ?ree1 z %[n 9 ,figure #dj4 ,! positive plate is plac$ 9 ! c5tre ) a sep>ator on ei!r side4 ,two negative plates are !n plac$ on ! outside4 ,! lugs on ! negative plates %\ld come opposite to ea* o!r4 ,a squ>e lead block hav+ a hole bor$ ?r\gh ! c5tre may be plac$ betwe5 ! two negative lugs4 ,! lugs are !n clamp$ toge!r ) a b9d+ po/ & a screw4 ,! plates are held 9 a compact bundle by two heavy rubb] b&s pass+ ar\nd !m4 ,ea* gr\p ( plates is !n plac$ 9 its prop] j> & ! j> fill$ full ( a mixture compos$ (3 #a4 ,f\r p>ts ( wat]1 & #b4 ,"o "p ( sulphuric acid4 ,! plates are n[ ready = =m+4 ,! cells are connect$ 9 s]ies by lead+ a wire f ! negative ( "o to ! positive ( ano!r & s on4 ,! t]m9als ( ! batt]y are !n connect$ to a /eady s\rce ( direct curr5t ( at lea/ t5 volts4 ,! positive pole ( ! batt]y %\ld be connect$ to ! positive ( ! curr5t s\rce & ! negative to ! negative4 ,! s\rce ( curr5t may be 7#a7 ! #aaj volt ,d4 ,c4 supply 9 s]ies ) a lamp bank z describ$ 9 ,*apt] ,,iv2 7#b7 ! #aaj volt ,a4 ,c4 supply aft] x has pass$ ?r\gh a rectifi]2 7#c7 ano!r batt]y1 or 7#d7 a %unt w\nd dynamo4 ,illu/ration3 ,,fig4 #db4--;,an empty ,/orage ,cell ,grid & also a ,pa/$ ,plate bo? ( :i* are on ! m>ket = exp]im5t]s :o wi% to build _! own ,cells4 ,! curr5t pass$ ?r\gh ! /orage cells dur+ ! =m+ process %\ld be ab\t "o amp]e = cells ( ! size describ$ above4 ,z soon z ! positive plates ( ! /orage cells h *ang$ to a d>k *ocolate-br[n color & ! negatives to a gray-slate1 disconnect ! /orage batt]y f ! s\rce ( curr5t & proce$ to use x j z y w\ld any ord9>y batt]y4 ,use x until x is exhau/$ & !n connect to ! *>g+ curr5t aga91 tak+ c>e to make c]ta9 t ! positive pole ( ! batt]y is connect$ to ! positive pole ( ! curr5t s\rce4 ,aft] ! cells h be5 re*>g$ & dis*>g$ 9 ?is mann] ab\t t5 times !y w be completely =m$ & ready = p]man5t s]vice4 ,complete directions = re*>g+ /orage cells & in/ructions = _! c>e & ma9t5ance w be f\nd fur!r on4 ,! only objection to ! /orage cells j describ$ is t ! pa/e is liable to fall out ( ! plates 9 "t4 ,! plates or grids z !y are call$ us$ 9 comm]cial /orage cells are ca/ 9 elaborate m\lds :i* make x possible to ov]come ?is difficulty4 ,su* grids _c h[ev] be made by ! exp]im5t]4 ,j>s1 pa/$ plates & empty grids may be pur*as$ f well kn[n firms deal+ 9 app>atus = ! exp]im5t]1 & ) _! aid x is possible to con/ruct a v sub/antial & durable /orage cell at home4 ,! empty grids or fully =m$ plates may be pur*as$ 9 ! foll[+ sizes3 ,positive or ,negative ,plate1 size #b #g_/h x #b #a_/b #c #a_/h x #b #g_/h #c #e_/h x #e #c_/d #d #c_/d x #b #g_/h #d #c_/d x #e #c_/d ,glass j>s w be f\nd satisfactory = /ation>y batt]ies4 ,rubb] j>s are h[ev] advisable = portable batt]ies4 ,j>s ( ! foll[+ sizes may be easily obta9$3 ,glass ,j>1 outside #c #c_/d x #d x #a #a_/b in*es ,glass ,j>1 outside #c #c_/d x #e x #a #a_/b in*es ,h>d ,rubb] ,j>1 outside4 #f #a_/b x #c #a_/b x #a #a_/b in*es ,h>d ,rubb] ,j>1 outside4 #f #a_/b x #f #a_/b x #a #a_/b in*es ,if ! empty grids are pur*as$1 !y %\ld be pa/$ 9 ! same mann] z ^? plates j describ$4 ,an empty grid ( ?is type is %[n 9 ,figure #db4 ,a pa/$ plate is %[n along side ( x4 ,! two negative plates 9 cells ( ?is type are fa/5$ toge!r by burn+ into a lug1 ,! lugs = ?is purpose may also be pur*as$ & w be f\nd inexp5sive4 ,! long lugs on ! negative plates are cut (f s t !y w only j project ?r\gh ! rectangul> holes 9 ! connect+ lug :5 ! latt] is 9 place1 z %[n by ,a 9 ,figure #dc4 ,! plates are burn$ into ! connect+ lug by us+ a r$ hot sold]+ iron to melt ! lead until !y fl[ toge!r at ^? po9ts4 ,?is is a job requir+ a little skill & ! exp]im5t] _h bett] practice burn+ "s odd bits ( lead toge!r fir/ s z to avoid all possibility ( spoil+ 8 plates4 ,illu/ration3 ,,fig4 #dc4--,two ,negative ,plates burn$ toge!r & ! ,connect+ ,lug us$4 ,! positive plate is plac$ 9 position1 z %[n 9 ,figure #dd4 ,wood5 sep>ators ( ! same size z ! plates are plac$ betwe5 ! plates & ! :ole /rapp$ toge!r ) heavy rubb] b&s ne> ! top & bottom4 ,! cells are !n plac$ 9 _! j>s & ! latt] p\r$ full ( electrolyte1 provid+ t ! batt]ies are to be ( ! /ation>y or op5 type4 ,if x is desirable t !y be portable & arrang$ s t ! acid w n easily spill1 x w be necess>y to seal !m at ! top4 ,! seal+ is accompli%$ by cutt+ a cov] /rip out ( ?9 wood :i* w slip d[n ov] ! lugs into ! j> s t x comes ab\t "o-half an in* bel[ ! top4 ,a small hole %\ld be bor$ 9 ! c5tre ( ! cov] /rip to receive a %ort piece ( h>d rubb] or lead tub+1 :i* w act z a v5t & p]mit ! gases =m$ dur+ *>g+ to escape or ! electrolyte to be empti$ at w4 ,illu/ration3 ,,fig4 #dd4--,! ,elem5ts ( a ,/orage ,cell compos$ ( two ,negative ,plates & "o ,positive ,plate 9 _! prop] position4 ,! cov] /rip %\ld fit into ! j> tightly s t :5 ! seal+ mixture is p\r$ 9 x w n run d[n ar\nd ! plates or into ! j>4 ,! top ( ! batt]y is !n p\r$ full ( a molt5 comp\nd ( asphaltum & pit*4 ,no attempt %\ld be made to seal ! batt]ies :5 !y conta9 acid4 ,! inside ( ! j> %\ld be clean & dry4 ,aft] ! cells are seal$ & fill$ ) electrolyte !y are ready = ei!r =m+ or *>g+1 dep5d+ ^u :e!r ! empty grids 7 pur*as$ & pa/$ by ! exp]im5t] or ! plates 7 b\ght already pa/$ & =m$4 ,if !y require =m+1 !y mu/ be put ?r\gh ! same =m+ process :i* has already be5 describ$4 ,! f9i%$ cells :5 seal$ w appe> l ^? %[n 9 ,figure #de1 accord+ to ! sizes ( plates & j>s us$4 ,illu/ration3 ,,fig4 #de4--,?ree diff]5t sizes ( ,/orage ,cells :i* may be pur*as$ ready made or built by ! exp]im5t] out ( prep>$ mat]ials z expla9$4 ,re*>g+ & ,c>+ = ,/orage ,cells4 ,/orage cells are especially affect$ by ! usage giv5 !m4 ,if !y are mi/reat$ !y w quickly g to pieces1 :]eas1 on ! o!r h& if well treat$ !y w la/ indef9itely4 ,x is important t ! electrolyte us$ 9 ! cells %\ld always be ( ! prop] /r5g?4 ,! only accurate me?od ( prep>+ ! electrolyte is ) ! aid ( a 99hydromet]994 ,a hydromet] is an in/rum5t = det]m9+ ! specific gravity ( solutions4 ,x is a little device :i* looks some:at l a !rmomet]4 ,x is plac$ 9 ! solution & all[$ to float4 ,!re is a numb]$ scale along ! upp] "p ( ! hydromet] & ! 99specific gravity99 or /r5g? ( ! solution is indicat$ on ! scale by ! po9t :i* is level ) ! surface ( ! solution4 ,! normal specific gravity = a /orage batt]y solution %\ld be ab\t #a4bej4 ,! /r5g? c be increas$ by add+ m acid & decreas$ by add+ wat]4 ,ord9>y comm]cial or te*nical grades ( sulphuric acid & ord9>y wat] are satisfactory = prim>y batt]ies1 b ! acid & wat] us$ 9 mak+ ! electrolyte = /orage cells mu/ be 99*emically pure99 if y wi% to obta9 good results & desire y\r batt]ies to hold _! *>ge :ile /&+4 ,/orage cells c be re*>g$ ) ,,direct curr5t only4 ,a dynamo = re*>g+ /orage cells mu/ be ,,%unt w\nd4 ,! voltage ( ! *>g+ curr5t mu/ be great] ?an t ( ! /orage cells4 ,ab\t ?ree volts ( *>g+ curr5t w be requir$ = ea* cell ( ! /orage batt]y4 ,cells may be connect$ 9 multiple :5 re*>g+ s z to br+ ! voltage ( ! cells bel[ t ( ! *>g+ curr5t4 ,x w ( c\rse1 h[ev]1 take mu* long] to re*>ge cells connect$ 9 multiple ?an ! same cells connect$ 9 s]ies1 provid$ t ! amp]age ( ! curr5t is ! same4 ,/orage cells mu/ n be re*>g$ too rapidly4 ,x is bett] to re*>ge !m sl[ly r ?an too rapidly4 ,two amp]es is pl5ty = small cells ( #aj-ae amp]e h\rs capacity4 ,?ree amp]es is suffici5t = cells ( #ae-be amp]e h\rs capacity4 ,five to six amp]es is ! "r *>g+ rate = a #dj amp]e h\r batt]y & #h amp]es 9 ! case ( a #fj amp]e h\r batt]y4 ,illu/ration3 ,,fig4 #df4--;,a ,hydromet] = prep>+ & te/+ ! ,acid ,solution = ,/orage ,batt]ies4 ,/orage cells %\ld nev] be all[$ to /& dis*>g$ = any l5g? ( "t or ! plates are liable to become h>d5$ & sulphat$4 ,!y turn :ite :5 !y are sulphat$4 ,x w take a great deal ( *>g+ & re*>g+ to get !m back 9 %ape :5 once !y get 9 t condition4 ,nev] %ort circuit a /orage cell or dis*>ge x too rapidly4 ,:5ev] any great am\nt ( s$im5t collects 9 ! bottom ( ! j>s1 p\r out ! acid solution & wa% ! cell out ?or\ghly ) "s pure wat]4 ,! plates ( a /orage cell %\ld always be rais$ up (f ! bottom ( ! j>1 s t any s$im5t :i* collects w fall bel[4 ,illu/ration3 ,,fig4 #dg4--,! prop] way ( ,re*>g+ ,/orage ,cells f ! #aaj ,volts ,d4 ,c4 ,supply 9 s]ies ) a set ( ,lamps4 ,x is a v good plan to keep ! t]m9als ( a /orage cell or batt]y sme>$ ) vasel9e s t !y w n become corrod$4 ,y c tell :5 a /orage cell or batt]y is fully re*>g$ by ! color ( ! plates4 ,! positives w 9 t case be a d>k *ocolate br[n & ! negatives a light slate gray color4 ,a cell :i* is fully re*>g$ w indicate #b #a_/b volts on a voltmet] connect$ across its t]m9als :ile ! *>g+ curr5t is /ill on4 ,,*apt] ,,iii4 ,,h[ ,,to ,,r$uce ,,! #aaj ,v4 ,d4,c4 ,,or ,a4,c4 ,,to ,a ,,l[] ,,voltage ,,= ,,exp]im5tal ,,purposes4 ,x is (t5 desirable to op]ate exp]im5tal app>atus & o!r electrical devices f ! #aaj volt light+ circuit4 ,su* a circuit may be ei!r direct or alt]nat+1 commonly spok5 ( z ,d4,c4 & ,a4,c4 ,! easie/ me?od ( r$uc+ ! voltage ( ! #aaj volt circuit to a value :]e x c be us$ 9 place ( an ord9>y batt]y is to use a /ep-d[n trans=m]4 ,a trans=m] w1 h[ev]1 op]ate only on alt]nat+ curr5t & x is impossible to use x on a direct curr5t circuit4 ,illu/ration3 ,,fig4 #dh4--;,a ,lamp ,bank consi/+ ( a ,set ( #aaj-,volt ,lamps connect$ ,multiple & arrang$ to be plac$ 9 s]ies ) any device x is desir$ to use on ! #aaj-,volt ,curr5t4 ,x is !re=e necess>y to secure ! desir$ result by plac+ an adju/able resi/ance 9 ! circuit & ! mo/ practical me?od ( accompli%+ ?is is to use a lamp bank4 99,a ,lamp ,bank99 consi/s ( a numb] ( inc&esc5t lamps arrang$ on a bo>d s t any desir$ numb] may be quickly includ$ 9 or )drawn f ! circuit4 ,figure #dh illu/rates su* an arrangem5t4 ,x consi/s ( a numb] ( ,edison sockets ( ! type kn[n z flat-base porcela9 receptacles1 m\nt$ 9 two r[s ^u a suitable basebo>d4 ,six or t5 receptacles w usually prove suffici5t = ! ord9>y lamp bank4 ,! lamps are connect$ 9 s]ies-multiple4 ,! diagram 9 ! upp] left h& corn] ( ,figure #dh %[s j h[ ?is is done4 ,f\r b9d+ po/s %\ld be m\nt$ ^u "o end ( ! bo>d & m>k$ ,a1 ,b1 ,b & ,c z %[n4 ,b & ,b are connect$ toge!r1 or to use an electrical t]m1 are 9 common4 ,! #aaj volt supply is connect$ to ! po/s ,b & ,c4 ,if any electrical device is !n connect$ to ,a & ,b & a lamp plac$ 9 ea* "o ( ! receptacles1 ! lamps w be 9 s]ies ) ! app>atus & l[] ! voltage ( ! #aaj volt circuit to a value :]e x may be us$ = re*>g+ /orage cells1 op]at+ toy motors1 electroplat+1 light+ m9iature lamps1 runn+ toy railways1 etc4 #aaj volt c>bon lamps %\ld be us$ on a lamp bank op]at$ on a #aaj volt circuit4 ,c>bon lamps consume m curr5t ?an tung/5 lamps & x w !re=e n be necess>y to use z _m4 ,ea* #af c4p4 #aaj volt lamp us$ w all[ ab\t "o-half ( an amp]e to pass ?r\gh ! circuit4 ,?irty-two c&le p[] bulbs ( ! same voltage w pass ab\t "o amp]e1 :ile an #h c4p4 bulb w only p]mit "o-qu>t] ( an amp]e to fl[4 ,x is !re=e v easy to regulate ! am\nt ( curr5t fl[+ by us+ lamps ( diff]5t sizes & screw+ !m 9 or out ( ! receptacles4 ,a lamp bank su* z ?is may ( c\rse be us$ on ei!r ! #aaj volt ,a4 ,c4 or ,d4 ,c4 circuit4 ,,*apt] ,,iv4 ,,h[ ,,an ,,alt]nat+ ,,curr5t ,,may ,,be ,,*ang$ ,,into ,,direct ,,curr5t ,,by ,,means ,,( ,,an ,,electrolytic ,,rectifi]4 ,(t5times ! only s\rce ( electrical en]gy = exp]im5tal "w is ! #aaj volt alt]nat+ curr5t supply4 ,?is may be r$uc$ to a voltage suitable = op]at+ small batt]y motors1 tra9s1 lamps1 etc41 by means ( a lamp bank resi/ance or a /ep-d[n trans=m]4 ,direct curr5t is 99necess>y99 h[ev] 9 ord] to re*>ge /orage batt]ies & to op]ate _m o!r devices4 ,! electrolytic rectifi] is a device = *ang+ alt]nat+ curr5t into direct curr5t & w be f\nd satisfactory = ?is purpose1 provid$ too mu* is n dem&$ ( x4 ,x is fairly effici5t if us$ only to rectify small am\nts ( curr5t4 ,x is n effici5t :5 l>ge am\nts ( curr5ts are pass$ ?r\gh x & quickly becomes v hot 9 su* a case4 ,an electrolytic rectifi] consi/s ( an electrode ( iron or lead & "o ( alum9um imm]s$ 9 a solution ( sodium phosphate4 ,illu/ration3 ,,fig4 #di4--;,a ,s+le ,cell ( ,electrolytic ,rectifi]4 ,an ord9>y glass batt]y j> may be us$ to hold ! solution1 pref]ably "o measur+ #e x #g in*es4 ,! electrodes are support$ by a wood5 cov] :i* also s]ves to prev5t ! solution f evaporat+4 ,! cov] may be circul> 9 =m & simply re/ on ! top ( ! j> or may h a groove turn$ on ! und]side s t x fits ! rim ( ! j> snugly4 ,x is a wise precaution to ?or\ghly saturate ! cov] ) p>aff9 by imm]s+ x 9 a molt5 ba? ( t mat]ial4 ,if ! cov] is all[$ to rema9 9 ! molt5 p>aff9 until all bubbles h ceas$ to rise1 ! p>aff9 w ?or\ghly p]meate ! wood & protect x f ! action ( ! ,*emical solution us$ 9 ! rectifi]4 ,illu/ration3 ,,fig4 #ej4--;,an ,electrode cut out ( ,%eet ,metal4 ,! top is b5t ov] at "r angles & drill$ s t x c be m\nt$ on ! und]side ( ! cov]4 ,z /at$ above1 "o electrode may be made ( iron or lead4 ,! o!r %\ld be alum9um4 ,! electrode may be cut out ( %eet metal & made 9 ! =m ( a /rip ab\t "o & "o-half in*es wide & six in*es long4 ,! top ( ea* electrode is b5t ov] at "r angles & bor$ ) a small drill & an #h-cb brass ma*9e screw is pass$ ?r\gh ! hole & ?r\gh ! cov] into ! bottom ( ! b9d+ po/ m\nt$ on ! top ( ! cov]1 !reby s]v+ n only to fa/5 ! electrode securely 9 place to ! und]side ( ! cov]1 b also to e/abli% connection betwe5 ! electrode & ! b9d+ po/ itself4 ,electrodes :i* are cut out ( %eet metal possess ! disadvantage t !y are n q z effici5t & w n la/ z long z electrodes :i* are ca/4 ,ca/ electrodes are mu* heavi] & f> m effici5t 9 _m o!r ways4 ,!y _c be easily made by ! "y exp]im5t]1 b may be procur$ f any "o ( sev]al firms deal+ 9 supplies = exp]im5t]s4 ,! "r h& sket* 9 ,figure #eb %[s h[ ! electrodes %\ld appe> :5 !y are m\nt$ 9 position on ! und]side ( ! cov]4 ,!y are plac$ ab\t two & "o-half in*es to ?ree in*es ap>t4 ,! solution is =m$ by dissolv+ sodium-phosphate 9 wat] until a saturat$ solution is =m$1 t is1 until ! wat] w n dissolve any m4 ,sodium-phosphate dissolves r sl[ly & x w be necess>y to /ir ! solution & cru% ! lumps :i* =m ) a /ick or glass rod4 ,fill ! j>s ne>ly to ! top & !n place ! electrodes into position4 ,illu/ration3 ,,fig #ea4--;,a ,ca/ ,electrode w la/ mu* long] ?an "o cut f ,%eet ,metal4 ,ca/ ,electrodes l t above are on ! m>ket & c be pur*as$ v reasonably4 ,! action ( ! electrolytic rectifi]1 9 *ang+ alt]nat+ curr5t into direct curr5t1 is int]e/+ & peculi>4 ,! rectifi] acts mu* l a valve :i* op5s "o way & closes ! o!r4 ,if a batt]y is connect$ to ! electrodes ( a rectifi]1 ! positive pole ( ! batt]y be+ connect$ to ! lead or iron electrode & ! negative ( ! batt]y to ! alum9um electrode ( ! rectifi]1 ! curr5t f ! batt]y w fl[ ?r\gh ! rectifi] & no?+ unusual w happ54 ,if1 h[ev]1 ! poles are rev]s$ s t ! positive pole is connect$ to ! alum9um electrode1 oxyg5 gas w =m on ! alum9um4 ,! action ( ! oxyg5 gas is to comb9e ) ! alum9um & =m a coat+ ( 99alum9um oxide99 all ov] ! electrode4 ,alum9um oxide is an insulator & x !re=e quickly =ms an insulat+ coat+ :i* %ields ! electrode f ! solution & /ops ! passage ( ! curr5t4 ,?is action is almo/ in/antane\s4 ,illu/ration3 ,,fig4 #eb4--;,a complet$ s+le ,cell ,rectifi]4 ,! "r h& sket* %[s h[ ! ,electrodes are m\nt$ on ! und]side ( ! cov]4 ,if ! rectifi] is connect$ to an alt]nat+ curr5t supply x w act j l a valve p]mitt+ ! curr5t to fl[ 9 "o direction b /opp+ x :5ev] ! alum9um electrode is 99positive994 ,! result+ curr5t is !re=e1 "u prop] conditions1 an int]mitt5t curr5t fl[+ only 9 "o direction4 ,an alt]nat+ curr5t may be repres5t$ by a wavy l9e drawn above & bel[ a /raight l9e4 ,e "t t ! wavy l9e crosses ! /raight l9e x repres5ts an alt]nation or a rev]sal ( ! direction 9 :i* ! curr5t fl[s4 ,illu/ration3 ,,fig4 #ec4--;,a ,diagram %[+ h[ a ,rectifi] cuts (f "o-half ( ! ,alt]nat+ ,curr5t ,wave & *anges x into ,pulsat+ ,direct ,curr5t4 ,! direct curr5t f an electrolytic rectifi] work+ "u prop] conditions is practically "o-half ( ! alt]nat+ curr5t wave & may be repres5t$ by ! s]ies ( waves m>k$ by ,c 9 ! l[] "p ( ! illu/ration 9 ,figure #ec4 ,x w be notic$ t ^! l9es d n cross ! /raight l9e & ! curr5t !re=e does n rev]se b fl[s 9 "o direction only4 ,:5 a s+le cell ( rectifi] is us$ on ! #aaj volt curr5t supply1 x %\ld be plac$ 9 s]ies ) a lamp bank or a /ep-d[n trans=m] s t ! curr5t is r$uc$ to l[] voltage4 ,figure #ed %[s h[ to connect a /orage cell 9 s]ies ) a s+le cell ( rectifi] & a lamp bank s t ! /orage cell may be re*>g$ f ! alt]nat+ curr5t4 ,a /ep-d[n trans=m] w be f\nd m effici5t & n q s wa/eful ( curr5t z a lamp bank4 ,! rectifi] & ! /orage cell are simply connect$ 9 s]ies ) ! second>y ( ! /ep-d[n trans=m] 9 ord] to secure ?is result4 ,illu/ration3 ,,fig4 #ed4--;,circuit %[+ h[ a ,s+le ,cell ( ,rectifi] %\ld be connect$ 9 s]ies ) a ,lamp ,bank to ,re*>ge a ,/orage ,cell4 ,a is ! ,alum9um ,plate & ,l ! ,lead or ,iron ,plate4 ,illu/ration3 ,,fig4 #ee4--;,diagram %[+ ! ,diff]5ce 9 ,curr5t aft] x has be5 pass$ ?r\gh a ,s+le ,cell or ,rectifi] & aft] pass+ ?r\gh a ,f\r-,cell ,rectifi]4 ,! negative pole ( ! /orage cell mu/ always be connect$ to ! alum9um electrode ( ! rectifi]4 ,! s]ies ( little curv$ l9es at ! bottom ( ,figure #ec :i* repres5t ! alt]nat+ curr5t aft] x has be5 *ang$ into direct curr5t by ! action ( ! rectifi]1 h a space betwe5 ea* two1 %[+ t !re are p]iods dur+ :i* no curr5t fl[s b t ! curr5t is int]mitt5t & made up ( a numb] ( %ort impulses4 ,"o-half ( ! alt]nat+ curr5t is !re=e really wa/$4 ,x is possible1 by means ( f\r cells ( rectifi]1 to s connect !m t bo? halves ( ! alt]nat+ curr5t wave are utiliz$ & ! spaces are fill$ up z %[n 9 ! l[] "p ( ,figure #ee4 ,illu/ration3 ,,fig4 #ef4--;,diagram %[+ h[ a ,f\r-,cell ,rectifi] is connect$4 ,! ,alt]nat+ ,curr5t ,s\rce is connect$ to ,c & ,d4 ,! ,direct ,curr5t is tak5 (f at ,a & ,b4 ,! ,electrodes m>k$ ,a1 ,a1 ,a1 ,a are ! ,alum9um ,electrodes4 ,l1 ,l1 ,l1 ,l may be ,lead or ,iron4 ,! curr5t :i* w\ld normally be 9 a rev]se direction1 & !re=e bel[ ! /raight l9e1 has be5 completely rev]s$ s t x fl[s 9 ! same direction z t above ! l9e4 ,figure #ef %[s h[ to connect f\r cells ( rectifi] 9 ord] to secure ?is result4 ,an electrolytic rectifi] compos$ ( cells approximately #e x #g in*es1 z describ$1 w n effici5tly h&le a curr5t ( ov] two to two & "o-half amp]es4 ,a f\r cell rectifi] w op]ate to ! be/ advantage on a voltage ov] #ej1 & = t reason x is always be/ to use a lamp bank or /ep-d[n trans=m] 9 connection ) x4 ,:5 ! solution 9 a rectifi] becomes hot x w n op]ate z effici5tly z :5 cold4 ,! solution becomes exhau/$ aft] a c]ta9 am\nt ( usage & requires r5ewal4 ,?is condition w be indicat$ by ! failure ( ! rectifi] to op]ate prop]ly4 ,! old solution %\ld !n be ?r[n away & ! j>s & electrodes wa%$ & clean$ ?or\ghly be=e ! new solution is p\r$ 94 ,illu/ration3 ,,fig4 #eg--;,a ,complete ,f\r-,cell ,rectifi] connect$ toge!r & ,m\nt$ 9 a ,tray4 ,,*apt] ,v4 ,,h[ ,,to ,,build ,a ,,/ep-,,d[n ,,trans=m] ,,= ,,r$uc+ ,,! #aaj ,,volt ,a4 ,c4 ,,= ,,exp]im5tal ,,purposes4 ,a ,/ep-,d[n ,trans=m] w r$uce ! #aaj volt alt]nat+ curr5t to a l[ voltage4 ,^! l[ voltage curr5ts are /ill alt]nat+ b w op]ate almo/ all sorts ( direct curr5t app>atus ) ! exception ( p]man5t magnet type motors :i* are n[ practically obsolete4 ,a suitable /ep-d[n trans=m] may be us$ to op]ate electrical toys1 su* z small fans1 motors & m9iature electric railway tra9s1 r+ bells1 light small lamps1 op]ate sp>k coils1 etc41 9 fact ! diff]5t uses are practically unlimit$1 dep5d+ only ^u ! +5uity ( ! exp]im5t]4 ,illu/ration3 ,,fig4 #eh4--;,details ( ! two diff]5t ,pieces ( ,%eet ,iron us$ 9 build+ up ! ,core4 ,suffici5t ( ea* piece are requir$ to =m a pile ( ea* ?ree-qu>t]s ( an in* ?ick4 ,a /ep-d[n trans=m] _c be us$ to re*>ge /orage cells or = electro-plat+ unless ! curr5t is fir/ pass$ ?r\gh a rectifi]4 ,a trans=m] is bo? 9 pr9ciple & con/ruction really v simple4 ,x consi/s simply ( two coils ( wire w\nd ar\nd an iron core4 ,"o coil consi/s ( _m turns ( f9e wire & is connect$ to ! #aaj volt alt]nat+ curr5t4 ,?is coil is call$ ! 99prim>y994 ,! o!r coil consi/s ( a small] numb] ( turns ( l>g] wire & is call$ ! 99second>y994 ,! l[] voltage curr5ts are obta9$ f ! second>y4 ,! fir/ /ep to take 9 mak+ a trans=m] is to procure "s %eet iron ( ! sort us$ = mak+ /ove pipes4 ,x is call$ /ove pipe iron4 ,?is iron w h to be cut into a numb] ( pieces l ,a & ,b 9 ,figure #eh4 ,! exact %ape & dim5sions are mo/ easily und]/ood f ! illu/ration4 ,a some:at resembles a ?ree-prong$ =k1 :ile ,b is simply a /rip #b #e_/h in*es long & #a_/b in* wide4 ,illu/ration3 ,,fig4 #ei4--,! ,me?od us$ 9 pil+ up ! ,/rips to ,assemble ! ,core4 ,a suffici5t quantity ( ea* piece w be requir$ to make a pile ?ree-qu>t]s ( an in* ?ick :5 tightly compress$4 ,! be/ me?od ( proc$ure is to lay out "o piece l ,a v accurately & !n cut x out4 ,hamm] x out p]fectly flat & use x z a patt]n to lay out ! o!r pieces )4 ,! cutt+ c be done ) a pair ( ord9>y t9 snips4 ,! pieces %\ld all be cut v accurately & truly s t !y w mat* :5 pil$ up4 ,! r\gh edges ( ! iron c be smoo!d up ) a file4 ,figure #fj %[s h[ ! core %\ld look :5 x is assembl$4 ,x %\ld =m a rectangle ?ree & ?ree-qu>t]s in*es long & two & five-eigh?s in*es wide4 ,! me?od ( pil+ up ! 99lam9ations991 z ! pieces =m+ ! core are call$1 is illu/rat$ 9 ,figure #ei4 ,"o ( ! /rips ,b is plac$ aga9/ ! op5 end ( ,a4 ,! next set ( /rips is arrang$ 9 ! same mann] except t ! position is rev]s$ s t ! /rip ,b is at ! opposite end ( ! pile4 ,?is me?od is cont9u$1 rev]s+ ea* alt]nate set ( /rips until ! pile is complete z %[n 9 ,figure #fj4 ,aft] ! core has be5 assembl$1 exam9e x c>efully & make c]ta9 t none ( ! /rips are ( ! wrong size s t "s protrude f>!r ?an o!rs4 ,! next /ep 9 ! "w is to make ! w9d+s1 ,! w9d+s are ea* made on a c>dbo>d tube hav+ an inside diamet] ( ab\t #a #a_/af in*es4 ,! tubes may be made by roll+ a /rip ( wrapp+ pap] ar\nd a piece ( broom h&le or "s o!r r\nd object ( ! prop] size4 ,! edges ( ! tube %\ld be glu$ s t x _c unroll4 ,illu/ration3 ,,fig4 #fj4--;,assembly ( ! ,core4 ,! 99second>y w9d+99 is an in* & n9e-sixte5?s long & "o & ?irte5-sixte5?s ( an in* 9 diamet]4 ,x is compos$ ( #abj turns ( ,no4 #ag ,b4 ,s4 gauge s+le cotton cov]$ wire w\nd 9 six lay]s4 ,a tap is l$ out at ! end ( ! second lay]4 ,! 99prim>y99 is "o & n9e-sixte5?s in*es 9 diamet] & "o & "o-sixte5? long4 ,x is compos$ ( #ajdj turns ( wire w\nd 9 #ac lay]s4 ,illu/ration3 ,,fig4 #fa4--;,details ( ! ,prim>y & ,second>y ,w9d+s4 ,illu/ration3 ,,fig4 #fb4--,%[+ ! ,core completely assembl$ ) ! ,prim>y & ,second>y 9 position4 ,p1 ,p are ! ,prim>y ,t]m9als4 #a1 #b & #c are ! ,second>y ,t]m9als4 ,! w9d+s mu/ be c>efully made & e c>e tak5 to see t !y are prop]ly insulat$4 ,x is a v good plan to ins]t a lay] ( pap] betwe5 ea* two lay]s ( wire4 ,aft] ! w9d+s are f9i%$ !y are ready to assemble on ! core4 ,9 ord] to put !m 9 place1 ! core mu/ be tak5 ap>t fir/4 ,! prim>y & second>y g along side ( ea* o!r on ! c5tre tongue ( ! ,a /rips4 ,! core is put toge!r aga9 ) ! w9d+s 9 position by slipp+ ea* alt]nate ,a /rip ?r\gh f ! opposite direction s t :5 x is all assembl$ ! result is l t %[n 9 ,figure #fb4 ,! trans=m] is n[ ready = m\nt+4 ,! usual me?od ( m\nt+ a /ep-d[n trans=m] is to place x 9 an iron box or case4 ,?is is ( c\rse ! be/ way because ! w9d+s & core are !n protect$4 ,! exp]im5t] :o wi%es to g to ! tr\ble ( build+ an iron box = 8 trans=m] w f9d x wor? ! "t4 ,= ! b5efit ( ^? h[ev] :o may wi% to m\nt ! trans=m] on a swit*bo>d or z "p ( "s app>atus1 ! s*eme %[n 9 ,figure #fc is sugge/$4 ,! base consi/s simply ( a rectangul> piece ( h>dwood :i* has be5 giv5 a coat ( %ellac4 ,illu/ration3 ,,fig4 #fc4--,! ,/ep-d[n ,trans=m] m\nt$ on a ,wood5 ,base4 ,! trans=m] core re/s on two wood5 /rips m>k$ ,s & ,s 9 ! illu/ration4 ,x is clamp$ to ! base by two /rips1 ,t & ,t1 held 9 position by r\nd head wood screws at ea* end4 ,! t]m9als ( ! prim>y w9d+ are l$ to ! two b9d+ po/s1 m>k$ ,p ,p4 ,! second>y t]m9als are connect$ to ?ree b9d+ po/s1 m>k$ #a1 #b & #c4 ,! #aaj volt ,a4 ,c is connect$ to ! prim>y po/s ,p ,p by means ( a flexible wire & plug :i* c be screw$ into ! ne>e/ lamp socket4 ,! l[ voltage is secur$ f ! b9d+ po/s #a1 #b & #c4 ,b9d+ ,po/s #a & #b w give #b volts ,b9d+ ,po/s #b & #c w give #h volts ,b9d+ ,po/s #a & #c w give #ab volts ,illu/ration3 ,,fig4 #fd4--;,a detail$ ,draw+ %[+ h[ ! ,sides ( ! ,case are =m$ by b5d+ a long /rip ( ,%eet ,iron at f\r po9ts4 ,! draw+s 9 ,figures #fd1 #fe & #ff w be ( assi/ance to ^? :o wi% to enclose ! trans=m] 9 an iron case in/ead ( m\nt+ x on a bo>d4 ,! case is made ( %eet iron4 ,! sides are compos$ ( a /rip ( %eet iron fifte5 & sev5-eigh?s in*es long & two & ?ree-qu>t]s in*es wide4 ,! /rip %\ld be b5t at f\r po9ts s z to =m a rectangul> box1 ! sides ( :i* are f\r & ?ree-sixte5? in*es long & ! front & back1 ?ree & n9e-sixte5?s4 ,! ends ( ! /rip %\ld ov]lap ab\t ?ree-eigh?s ( an in* & be rivet$ or sold]$4 ,! bottom may be fa/5$ to ! sides ) a c\ple ( rivets or by sold]+ at "o or two po9ts4 ,! bottom & top ( ! case %\ld bo? be ! same4 ,!y are made f a rectangul> %ap$ piece ( %eet iron f\r & sev5-eigh?s in*es long & f\r & "o-qu>t] in*es wide4 ,a not* five-sixte5?s ( an in* squ>e is cut out ( ea* corn] & ! sides & ends !n fold$ d[n along ! dott$ l9es z indicat$ 9 ,figure #fe4 ,illu/ration3 ,,fig4 #fe4--;,details ( ! ,top & ,bottom ( ! ,case4 ,! trans=m] is laid 9 ! case ) a small block ( wood "u ! core at ei!r side s z to raise ! w9d+s up (f ! bottom4 ,! second>y t]m9als are connect$ to b9d+ po/s m>k$ #a1 #b & #c 9 ,figure #ff4 ,^! b9d+ po/s are m\nt$ on insulat+ bu%+s :i* pass ?r\gh ! holes m>k$ ,no4 #a1 ,no4 #b & ,no4 #c 9 ,figure #fd4 ,! insulat+ bu%+s consi/ simply ( fibre wa%]s s t ! b9d+ po/s w n %ort circuit on ! metal case4 ,"o end ( a piece ( d\ble conductor lamp cord is l$ ?r\gh a hole 9 ! back ( ! case & sold]$ to ! two prim>y coil t]m9als4 ,! o!r end ( ! lamp cord is connect$ to an atta*m5t plug :i* may be screw$ into a lamp socket4 ,illu/ration3 ,,fig4 #ff4--,! complet$ ,trans=m]4 ,! trans=m] case is !n p\r$ full ( molt5 coil wax s t ! space ar\nd ! trans=m] is entirely fill$4 ,aft] ! wax has cool$1 fa/5 ! cov] on & x is complete4 ,arts & ,sci5ce ,s]ies ,no4 #h ,home-made ,electrical ,app>atus ,a ,practical ,h&book = ,amateur ,exp]im5t]s ,9 ,?ree ,p>ts 99,volume ,,ii99 ,second ,edition 99,,by99 99,a4 ,m4 ,p[ell99 ,,publi%$ ,,by ,,cole ,,morgan1 ,inc4 ,publi%]s ( ! ,arts & ,sci5ce ,s]ies ,p4,o4 ,,box #dgc ,,city ,,hall ,,/ation ,,new ,,york1 ,n4 ,y4 ,pr9t$ 9 ,u4 ,s4 ,a4 ,copyright #aiah by ,,cole ,,morgan1 ,inc4 ,,*apt] ,,vi4 ,,electric ,,measur+ ,,in/rum5ts ,galvanomet]s1 ,ammet]s1 ,voltmet]s4 ,h[ to ,make a ,galvanomet]4 ,if sev]al turns ( wire are wrapp$ ab\t a compass1 & a curr5t ( electricity s5t ?r\gh ! coil1 ! compass ne$le w be deflect$4 ,su* an in/rum5t is call$ a 99galvanomet]99 & may be us$ = detect+ v feeble curr5ts4 ,figure #fg %[s a v simple =m ( galvanomet] :i* may be made by w9d+ ab\t fifty turns ( ,no4 #cf ,b4 ,s4 ,gauge s+le silk cov]$ wire ar\nd an ord9>y pocket compass4 ,! compass is set on a block ( wood & ! wire w\nd ar\nd bo? ! compass & ! block4 ,! t]m9als ( ! wire are connect$ to two b9d+ po/s4 ,illu/ration3 ,,fig4 #fg4--;,a ,simple ,galvanomet]4 ,a galvanoscope ( ?is sort may also be us$ = a pol>ity indicator to di/+ui% betwe5 positive & negative poles4 ,connect an ord9>y dry cell to ! galvanomet] & ! ne$le w imm$iately sw+ to "o side or ! o!r1 dep5d+ ^u :i* way ! curr5t fl[s4 ,! c>bon ( ! dry cell is 99positive99 & ! z9c is 99negative994 ,note :i* way ! ne$le sw+s1 :e!r t[>d ! b9d+ po/ connect$ to ! positive pole or ! "o connect$ to ! negative pole4 ,x w sw+ t[>ds ! correspond+ pole :5 any o!r s\rce ( curr5t is connect$ to x & by kn[+ :e!r x po9ts t[>ds positive or negative x is v easy to det]m9e ! pol>ity4 ,! ,con/ruction ( ,ammet]s & ,voltmet]s4 ,! exp]im5t] w f9d a voltmet] & an ammet] to be v useful in/rum5ts ab\t ! work%op & laboratory4 ,a 99voltmet]99 is an in/rum5t design$ to measure electro-motive =ce or electrical pressure4 ,an in/rum5t design$ to measure rate ( fl[ ( curr5t is call$ an 99ammet]994 ,ammet]s & voltmet]s are really1 9 pr9ciple1 galvanomet]s1 ! scales ( :i* h be5 calibrat$ to read 9 amp]es or volts1 z ! case may be4 ,! little met]s describ$ bel[ are v simple b q s5sitive4 ,illu/ration3 ,,fig4 #fh4--;,details ( ! ,bobb94 ,! wood5 bobb9 :i* holds ! wire is %[n 9 ,figure #fh4 ,! exact dim5sions are be/ und]/ood f ! illu/ration4 ,! wood c be easily secur$ f an old cig> box4 ,9 lay+ out ! "w1 scrat* ! l9es on ! wood ) ! po9t ( a d>n+ ne$le4 ,p5cil l9es are too ?ick to p]mit ( accuracy 9 small "w4 ,! bobb9 %\ld be p]fectly squ>e & true :5 f9i%$4 ,f9i% by rubb+ ) f9e s&pap] & !n give x a coat ( %ellac4 ,two bobb9s w be requir$1 "o = ! voltmet] & "o = ! ammet]4 ,d n use any nails 9 putt+ ! bobb9s toge!r4 ,use /rong glue only4 ,! bobb9 = ! ammet] %\ld be w\nd full ( ,no4 #ad ,b4 ,s4 ,gauge d\ble cotton cov]$ magnet wire4 ,! voltmet] requires mu* small] wire4 ,no4 #cg ,b4 ,s4 ,gauge s+le silk cov]$ wire w s]ve ! purpose satisfactorily1 b a f9] size su* z ,no4 #ch or #dj1 is bett]4 ,su* f9e sizes w probably1 h[ev]1 prove m difficult = ! exp]im5t] to obta94 ,suffici5t wire %\ld be us$ to fill ! bobb9 up4 ,! wire %\ld be w\nd on c>efully 9 smoo? ev5 lay]s4 ,a small hole %\ld be bor$ 9 "o ( ! flanges1 ?r\gh :i* to pass ! end ( ! wire :5 />t+ ! fir/ lay]4 ,ab\t six in*es ( wire %\ld be left at bo? ends ( ! coils to make connection to ! t]m9als )4 ,! :ole w9d+ %\ld be giv5 a coat ( %ellac :5 f9i%$4 ,illu/ration3 ,,fig4 #fi4--;,details ( ! ,armature1 ,be>+s & ,po9t]4 ,! armature is a piece ( s(t /eel1 "o & "o-eigh? in*es long1 & "o-qu>t] ( an in* ?ick4 ,a "o-sixte5? in* hole is bor$1 slightly above ! c5tre ( ! armature1 to receive ! %aft4 ,! c5tre ( gravity is ?us ?r[n bel[ ! c5tre ( mass & ! po9t] atta*$ to ! armature w always return to z]o if ! in/rum5t is level4 ,! %aft is a piece ( "o-sixte5? in* bessem] /eel rod1 ?ree-eigh?s ( an in* long4 ,! ends are fil$ to a %>p po9t z %[n 9 ! upp] p]t ( ,fig4 #fi4 ,a small hole is bor$ 9 ! top ( ! armature almo/ directly ov] ! %aft z %[n 9 ,fig1 #fi to receive ! l[] end ( ! po9t]1 :i* is a piece ( ,no4 #af alum9um wire1 ?ree & "o-qu>t] in*es long4 ,! o!r end ( ! po9t] %\ld be flatt5$ slightly by tapp+ ) a hamm] & !n fil$ into a %ape resembl+ a spe> head4 ,illu/ration3 ,,fig4 #gj4--;,a complete ,voltmet] hav+ ! ,scale at ! top4 ,aft] all ! holes h be5 bor$ & be=e ! %aft & ! po9t] are 9 place1 ! armature mu/ be temp]$ s t x w reta9 its magnetism4 ,9 ord] to temp] ! armature1 heat x to a bright r$ & drop x imm$iately into a bas9 ( /rong salt wat]4 ,x may !n be magnetiz$ by rubb+ "o end aga9/ ! pole ( a /rong magnet4 ,! be>+s are =m$ by two #f-cb brass screws1 "o-half an in* long & hav+ a small hole 9 ! end to accommodate ! end ( ! %aft4 ,^! screws pass ?r\gh ! upp] flange ( ! bobb9 f ! opposite sides4 ,! holes 9 ! flanges %\ld be slightly small] ?an ! outside ( ! screw s t ! latt] w fit snugly & take hold z if ! wood 7 ?read$4 ,figures #gj & #ga %[ two diff]5t me?ods ( assembl+ & complet+ ! in/rum5ts4 ,9 "o1 ! bobb9 is m\nt$ on ! base & ! scale is at ! top4 ,9 ! o!r1 ?is relation is j turn$ ab\nd & ! bobb9 is at ! top & ! scale at ! bottom4 ,9 ! latt] case ! po9t] mu/ be atta*$ to ! bottom ( ! armature in/ead ( ! top4 ,illu/ration3 ,,fig4 #ga--;,an ,ammet] s con/ruct$ t ! ,scale is at ! bottom4 ,figure #gc %[s ! %apes & dim5sions ( ! wood5 p>ts :i* compose ! case4 ,a glass front slides 9 two %all[ grooves cut 9 ! wood5 sides1 "o-eigh? ( an in* f ! front4 ,glue & brass screws %\ld be us$ 9 putt+ ! case toge!r4 ,d n use iron or iron screws4 ,illu/ration3 ,,fig4 #gb4--,%[+ h[ ! ,armature1 ,%aft & ,po9t] are assembl$ = a ,met] hav+ ! ,scale at ! bottom4 ,! two b9d+ po/s connect$ to ! t]m9als ( ! wire on ! bobb9 %\ld be m\nt$ on ! base4 ,a small1 r\nd-head$ brass screw1 long en\gh to pass all ! way ?r\gh ! base w s]ve to level ! in/rum5t & br+ ! po9t] exactly at z]o4 ,if a little brass /rip is plac$ 9 ! slot 9 ! screw head & sold]$ !re s z to =m :at is kn[n z a w+$ screw1 ! adju/m5t may be made ) ! f+]s & )\t ! aid ( a screw driv]4 ,! scale is =m$ on a piece ( /iff :ite c>dbo>d directly "u ! po9t]4 ,! scale is support$ by glu+ x to two small wood5 blocks4 ,! v>i\s values are m>k$ on ! scale ) a p5 & ink4 ,! glass front %\ld !re=e n be put 9 place until ! in/rum5t has be5 calibrat$4 ,to prop]ly calibrate ! met]s1 !y mu/ be comp>$ ) a suitable /&>d4 ,! z]o value on ! met]s is normally 9 ! c5tre ( ! scale4 ,:5 a curr5t is pass$ ?r\gh ! bobb9s1 ! armature t5ds to sw+ ar\nd at "r angles4 ,b s9ce ! armature is pivot$ above its c5tre ( mass1 ! c5tre ( gravity is displac$ :5 x sw+s & ex]ts a pull 9 opposition to t ( ! bobb94 ,! am\nt ( sw+ w be great] z ! curr5t is correspond+ly /rong]4 ,! po9t] w sw+ ei!r to ! "r or to ! left1 dep5d+ ^u ! direction 9 :i* ! curr5t passes ?r\gh ! coil ( wire on ! bobb94 ,illu/ration3 ,,fig4 #gc4--;,details ( ! ,wood5 ,p>ts :i* =m ! ,case4 ,! z]o po9t on ! two in/rum5ts %[n 9 ! accompany+ illu/ration is at ! extreme left ( ! scales4 ,! po9t]s are b5t to ! left s t ! curr5t may be pass$ ?r\gh ! met]s 9 only "o direction & ! scales w h a great] range ( values4 ,9 ord] to calibrate ! ammet]1 place x 9 s]ies ) a /&>d ammet] hav+ a calibrat$ scale :i* is kn[n to be correct4 ,a set ( /rong batt]ies & a rheo/at %\ld be includ$ 9 ! circuit4 ,! arrangem5t is illu/rat$ 9 ,figure #gd4 ,! rheo/at is adju/$ s t v>i\s curr5t read+s are obta9$4 ,! positions ( ! po9t] on ! /&>d met] are c>efully not$ & correspond+ graduations made on ! scale ( ! o!r met] = ea* value4 ,illu/ration3 ,,fig4 #gd4--,%[+ h[ ! ,app>atus is arrang$ & connect$ = calibrat+ ! ,ammet]4 ,illu/ration3 ,,fig4 #ge4--,%[+ h[ ! ,app>atus is arrang$ & connect$ = calibrat+ ! ,voltmet]4 ,9 ord] to calibrate ! voltmet] x mu/ be comp>$ to a /&>d voltmet]4 ,! voltmet]s mu/ be plac$ 9 p>allel or %unt ) ea* o!r z %[n 9 ,figure #ge4 ,a swit* is connect$ to ! batt]y s t ! voltage ( a v>y+ numb] ( cells may be pass$ ?r\gh ! met]s4 ,9 ord] to secure a close adju/m5t ( ! voltage1 a rheo/at is plac$ across ! batt]y & swit* s t x %unts ! cells :i* are 9 circuit4 ,by adju/+ bo? ! rheo/at & ! swit*1 any voltage )9 ! maximum range ( ! batt]y may be secur$4 ,aft] ! met]s h be5 calibrat$ & assembl$1 !y are ready = s]vice & w =m a v useful & valuable "p ( ! exp]im5t]'s laboratory4 ,:5 us+ ! met]s rememb] t x is always necess>y t ! ammet] %all be 9 s]ies & ! voltmet] 9 p>allel or %unt ) ! circuit4 ,,*apt] ,,vii4 ,,curr5t ,,control ,,devices4 ,h[ to ,make a ,pole ,*ang+ ,swit* or ,curr5t ,rev]ses ,h[ to ,rev]se a ,small ,motor4 ,! swit* %[n 9 ,figure #gf is a v simple device :i* w be f\nd v h&y = _m purposes4 ,x consi/s ( two brass lev]s m\nt$ alongside ( ea* o!r & connect$ toge!r ) an insulat+ /rip or yoke be>+ a h&le s t !y c bo? be mov$ toge!r4 ,! lev]s are pivot$ at _! back ends & provid$ ) b9d+ po/s m>k$ ,b4 ,p4 & ,b4 ,p4 9 ! illu/ration4 ,! front ends ( ! lev]s sw+ ov] ?ree swit* contact po9ts prop]ly spac$ s t ! lev]s t\* ! adjo9+ contacts at ! same "t4 ,! contacts are m>k$ #a1 #b1 & #c4 ,illu/ration3 ,,fig4 #gf4--;,a ,pole *ang+ ,swit* = rev]s+ ,small ,motors or ! direction ( an ,electric ,curr5t4 ,we w suppose t ! exp]im5t] has "s device op]at$ by a batt]y & desires to arrange ! app>atus s t he c quickly rev]se ! t]m9als ( ! batt]y s z to s5d ! curr5t ?r\gh ! device 9 ei!r direction quickly & at w4 ,! app>atus to be op]at$ %\ld be connect$ to ! two b9d+ po/s m\nt$ on ! swit* lev]s & m>k$ ,b4 ,p4 & ,b4 ,p4 ,connect ! negative pole ( ! batt]y to ! contact m>k$ #b 7! c5t] "o71 & ! positive pole to bo? #a & #c 7! outside ones74 ,:5 ! swit* is ?r[n to ! "r s t ! lev]s re/ on ! contacts #b & #c1 ! "r h& lev] w be positive & ! left h& "o negative4 ,:5 ! swit* is ?r[n to ! left s t ! lev]s re/ on #a & #b1 ! left h& lev] w be positive & ! "r h& "o negative4 ,! curr5t has be5 rev]s$4 ,illu/ration3 ,,fig4 #gg4--,top view ( a small ,batt]y ,rheo/at ,a swit* su* z ?is makes x possible to quickly rev]se ! runn+ direction ( small motors4 ,9 ord] to accompli% ?is1 connect ! two bru%es on ! motor to ! two swit* lev]s4 ,connect ! contracts #a & #c 7! two outside ones7 toge!r & lead ! wire to "o t]m9al ( ! batt]y us$ = op]at+ ! motor4 ,9 case ! motor is op]at$ by a g5]ator or f ! #aaj volt curr5t1 connect ! wire to "o t]m9al ( ! p[] s\rce4 ,! middle contact on ! swit* 7m>k$ #b7 %\ld be connect$ to "o end ( ! field w9d+ on ! motor4 ,! o!r end ( ! field w9d+ %\ld be connect$ to ! rema9+ batt]y t]m9al or p[] s\rce4 ,mov+ ! swit* back & =? w s5d ! curr5t ?r\gh ! commutator 9 opposite directions & cause ! motor to run 9 ei!r direction z desir$4 ,h[ to ,make a ,small ,batt]y ,rheo/at = ,regulat+ ! ,spe$ ( ,small ,motors1 ,etc4 99,a ,rheo/at99 is a v>iable resi/ance = regulat+ ! am\nt ( curr5t fl[+ 9 a circuit4 ,x is a v useful device ab\t ! exp]im5tal laboratory4 ,x may be us$1 = regulat+ ! spe$ ( small motors1 ! am\nt ( curr5t fl[+ into a /orage batt]y :5 re*>g+1 ! brilliancy ( a lamp1 etc4 ,illu/ration3 ,,fig4 #gh4--;,details ( ! ,rheo/at ,base4 ,! l[] "p ( ! illu/ration is a cross section4 ,figure #gg %[s a =m ( small rheo/at :i* may be easily built by ! exp]im5t]4 ,x consi/s ( a coil ( ,g]man silv] resi/ance wire w\nd ar\nd a fibre =m & set 9 a groove 9 a wood5 base4 ,a brass lev] slides ov] ! edge ( ! resi/ance coil s t ! portion includ$ 9 ! circuit may be increas$ or decreas$ easily at w4 ,! dim5sions %[n 9 ! sev]al draw+s :i* foll[ are = a rheo/at hav+ a resi/ance ( approximately t5 ohms & suitable = g5]al exp]im5tal "w4 ,x is possible to use ! same plans & by d\bl+ ! dim5sions1 make a rheo/at :i* is mu* l>g] & may be us$ to c>ry heavi] curr5ts or :i* possesses m resi/ance4 ,illu/ration3 ,,fig4 #gi4--,look+ at ! ,base f ! bottom %[+ ! grooves 9 :i* ! ,wires are laid4 ,! details ( ! wood5 base are giv5 9 ,figures #gh & #gi4 ,! outside diamet] ( ! base is f\r in*es4 ,x is five-eigh?s ( an in* ?ick4 ,! l[] #g "p ( ,figure #gh %[s a cross section ( ! base4 ,! groove is ?ree & "o-eigh? in*es 9 diamet] inside1 five-sixte5?s ( an in* ?ick & five ?irty-seconds ( an in* wide4 ,! hole 9 ! c5tre ( ! base is to accommodate ! %aft ( ! swit* lev]1 ,two holes1 sev5-eigh?s ( an in* ap>t are drill$ at ! back ( ! base to accommodate ! b9d+ po/s4 ,! b9d+ po/s' holes & also ! hole 9 ! c5tre ( ! base = ! %aft are c\nt]sunk at ! bottom z %[n 9 ,figure #gi4 ,! fibre /rip :i* supports ! ,g]man silv] resi/ance wire is %[n 9 ,figure #hj4 ,x is eight in*es long1 ?ree-eigh?s ( an in* wide & "o-eigh? ( an in* ?ick4 ,if ! exp]im5t] has access to a la! x is possible to w9d ! wire on ! fibre /rip "u t5sion ) ! aid ( ! screw fe$ s t ! wire w g on v tightly & ) a small air space betwe5 ! turns4 ,:5 a la! is n available x w be necess>y to groove ! top & bottom ( ! fibre /rip ) ! aid ( a ?ree-corn]$ file4 ,! grooves %\ld be ev5ly spac$ & z close toge!r z possible4 ,!y s]ve to prev5t ! wire f slipp+ & ! adjac5t turns becom+ %ort circuit$4 ,! wire us$ to w9d ! /rip %\ld be ,no4 #bd ,b4 ,s4 ,gauge ,g]man ,silv] wire & %\ld be b>e4 ,w9d ! wire tightly into ! grooves 9 ! /rip & fa/5 bo? ends by loop+ ?r\gh a small hole bor$ 9 ! ends ( ! fibre = t purpose4 ,! fibre /rip c be b5t s t x w fill 9 ! groove 9 ! wood5 base by heat+ x 9 ! flame ( a buns5 burn]4 ,x %\ld n1 ( c\rse1 be heat$ too hot or ! fibre w burn4 ,w>m x ?or\ghly & b5d into a circle ( ! same diamet] z ! groove 9 ! base4 ,!n =ce ! /rip into ! groove ) ! two ends opposite ! two b9d+ po/ holes4 ,! /rip %\ld fit into ! groove tightly s t !re is no dang] ( x %ift+ or slipp+ out4 ,illu/ration3 ,,fig4 #hj4--,! ,g]man-silv] ,resi/ance ,wire is w\nd ar\nd a ,fibre ,/rip4 ,! details ( ! swit* lev]1 knob & b9d+ po/s1 are %[n 9 ,figure #ha4 ,! lev] is made ( %eet brass cut into ! %ape %[n & is "o & ?ree-qu>t] in*es long4 ,! knob is simil> to ^? us$ on typewrit]s = turn+ ! pap] roll]4 ,x is fitt$ ) a ?read$ /em m\ld$ into ! head4 ,^! knobs may be obta9$ at almo/ any supply h\se c>ry+ goods = exp]im5t]s4 ,! lev] is slipp$ ov] ! /em & clamp$ tightly aga9/ ! knob by a nut on ! "u side4 ,! end ( ! /em or %aft fits into ! hole 9 ! c5tre ( ! wood5 base4 ,slip a wa%] ov] ! end & !n ?read on a brass wa%]4 ,tight5 ! nut up until ! end ( ! lev] makes firm contact ) ! resi/ance wire b is n s tight t x b9ds & _c be easily mov$ by turn+ ! knob4 ,:5 ! "r position = ! nut is f\nd1 sold] x to ! /em s t x _c *ange its adju/m5t4 ,illu/ration3 ,,fig4 #ha4--,! ,lev]1 ,knob1 ,b9d+ ,po/s1 etc4 ,! complet$ rheo/at is %[n 9 ,figure #hb4 ,! "r h& t]m9al ( ! ,g]man ,silv] wire is connect$ to ! "r h& b9d+ po/4 ,! o!r b9d+ po/ is connect$ to ! wa%] ar\nd ! lev] %aft on ! "u side ( ! base4 ,! wires %\ld be laid 9 grooves cut 9 ! bottom ( ! base = t purpose4 ,drive a brass head$ uphol/]]'s nail into ! base ne> ! left h& t]m9al ( ! resi/ance s t :5 ! lev] is swung ar\nd 9 t direction z f> z x w g1 ! tack w raise ! lev] up (f ! resi/ance wire & break ! circuit completely4 ,two small nails %\ld be driv5 into ! base 9 su* a position t !y w limit ! sw+ ( ! lev] & prev5t x f mov+ s f> t x passes ov] ! ends ( ! resi/ance unit4 ,! rheo/at may be connect$ 9 a circuit by atta*+ two wires to ! b9d+ po/s4 ,x %\ld be plac$ 9 s]ies ) any device :i* x is desir$ to regulate4 ,! c>ry+ capacity is limit$ to two amp]es ow+ to ! fact t a heavi] curr5t ?an ?is w cause ! wire to ov]heat4 ,turn+ ! knob s t ! lev] moves t[>ds ! uphol/]]'s nail1 :i* raises x up (f ! wire1 increases ! am\nt ( resi/ance 9 ! circuit & cuts d[n ! curr5t1 until ! lev] slides up on ! nail :5 ! circuit is brok5 entirely4 ,mov+ ! knob 9 ! o!r direction decreases ! resi/ance & increases ! curr5t until ! lev] has mov$ z f> z x may1 :5 ! curr5t w be at a maximum4 ,illu/ration3 ,,fig4 #hb4--,! complet$ ,rheo/at4 ,,*apt] ,,viii4 ,,h[ ,,to ,,make ,a ,,telegraph ,,key ,,& ,,s\nd] ,,& ,,in/all ,a ,,telegraph ,,l9e4 ,! mod]n telegraph consi/s ess5tially ( f\r ?+s3 #a4 ,a batt]y :i* produces ! electric curr5t4 #b4 ,a wire to conduct ! curr5t f "o po9t to ano!r4 #c4 ,a key or swit* = turn+ ! curr5t (f & on4 #d4 ,an electro-magnetic receiv+ app>atus1 :i* *anges ! pulsations ( ! electric curr5t into s\nds4 ,illu/ration3 ,,fig4 #hc4--,key ,frame4 ,its op]ation is n1 z _m suppose1 complicat$ & difficult to und]/&1 b is q simple4 ,! key is really a =m ( swit* & is simply a contrivance = controll+ ! electric curr5t4 ,x consi/s ( a /eel lev]1 pivot$ 9 ! c5tre1 & provid$ ) a rubb] knob1 :i* ! op]ator grasps lightly ) ! ?umb & =ef+]4 ,:5 ! lev] is press$ d[nw>ds1 a plat9um po9t on ! "u side is br\ght into contact ) ano!r simil> po9t set into a rubb] bu%+ 9 ! base ( ! key1 s t !re is no electrical connection betwe5 ! two po9ts unless ! key is press$ d[n or clos$ z x is usually t]m$4 ,! receiv+ device1 or s\nd]1 consi/s ( two electro-magnets m\nt$ on a base "u a flat /rip or iron1 call$ ! armature1 :i* is attract$ by ! magnetism ( ! electro-magnets :5 a curr5t fl[s ?r\gh !m1 & is )drawn by a spr+ :5 no magnetism is produc$ by ! w9d+s4 ,illu/ration3 ,,fig4 #hd4--,s\nd] ,frame4 ,! armature is usually m\nt$ on a /rip ( brass or alum9um call$ ! lev]4 ,! lev] /rikes aga9/ an anvil & produces ! clicks :i* =m ! dots & da%es ( ! telegraph alphabet4 ,e "t ! key is press$1 an electric curr5t goes ?r\gh ! l9e1 caus+ ! magnets to draw ! armature d[nw>d & produce a click4 ,:5 ! key lev] is releas$1 ! curr5t is %ut (f & ! lev] flies up & clicks aga9/ ! top ( ! anvil4 ,! "t betwe5 ! fir/ & second clicks may be easily v>i$ at w1 by *ang+ ! l5g? ( "t t ! key lev] is held d[n4 ,two clicks v close toge!r1 made by press+ ! key & imm$iately releas+ x1 are call$ a dot4 ,a da% is made by press+ ! key d[n & hold+ x d[n = a fraction ( a second s t ! int]val betwe5 ! fir/ & second clicks is ab\t ?ree times z long z t betwe5 ! clicks ( a dot4 ,illu/ration3 ,,fig4 #he4--,! ,electro ,magnets4 ,any boy c make a simple telegraph set q easily4 ,! only drawback ( su* an app>atus1 h[ev]1 is t x is usually n practical = long l9es b may only be us$ = tick+ messages f "o room to ano!r4 ,x is equally possible = ! "y exp]im5t] to make a p]fectly practical telegraph outfit :i* w op]ate ov] a l9e a mile long1 if he is will+ to give ! "t & labor necess>y to ! "w4 ,! telegraph set-describ$ bel[ is "o :i*1 because ( its simplicity1 p>ticul>ly l5ds itself to con/ruction by ! "y exp]im5t] ^: tools are r limit$4 ,9 ord] to make a really practical telegraph outfit1 x is almo/ ess5tial t ! key & s\nd] frame be made out ( ca/ iron s z to give ! in/rum5ts ! requisite /iffness4 ,x is easi] to use ca/+s ?an to attempt to b5d ! p>ts out ( metal4 ,9 ord] to secure ! prop] ca/+s x w be necess>y to fir/ make a set ( patt]ns4 ,?is is n v difficult4 ,! key frame is %[n 9 ,figure #hc & ! ,s\nd] frame 9 ,figure #hd4 ,! patt]ns %\ld be cut out ( wood accord+ to ! exact %ape & dim5sions %[n 9 ! illu/rations4 ,omit all ! holes1 h[ev]1 because no holes %\ld appe> 9 ! patt]ns b only 9 ! f9i%$ ca/+s4 ,illu/ration3 ,,fig4 #hf--,! ,s\nd] ,armature4 ,! patt]ns %\ld be made p]fectly smoo? & be a good1 clean job ?r\gh\t4 ,aft] !y are f9i%$1 give !m ea* a coat ( %ellac & !y are ready = ! f\ndry4 ,almo/ any iron f\ndry w make up ! ca/+s if suppli$ ) ! patt]ns4 ,if a numb] ( exp]im5t]s *ip 9 & make up a set ( patt]ns f :i* sev]al sets ( ca/+s are ord]$ at ! same "t1 ! co/ w be v slight4 ,aft] ! ca/+s are secur$1 !y %\ld be clean$ up ) a file & drill$ accord+ to ! illu/ration 9 ,figures #hc & #hd4 ,sev]al ( ! holes %\ld be tapp$ to receive an #h-cj ma*9e screw4 ,su* holes are m>k$ 9 ! illu/rations4 ,! holes n m>k$ ,tap %\ld be j l>ge en\gh to all[ an #h-cb screw to slip ?r\gh4 ,illu/ration3 ,,fig4 #hg4--,s\nd] ,frame ) ,lev] 9 ,position4 99,! ,electro-magnets99 are illu/rat$ 9 ,figure #he4 ,! magnet core is made ( a piece ( #e-af in* r\nd iron rod an in* & a qu>t] long4 ,a fibre wa%]1 ?ree-qu>t]s ( an in* 9 diamet] is fitt$ ov] ea* end ( ! core4 ,"o end ( ! core is drill$ & tapp$ to receive an #h-cb screw4 ,! magnet bobb91 be=e w9d+ is %[n at ! left ( ! illu/ration & a f9i%$ magnet at ! "r4 ,two magnets are requir$4 ,!y %\ld bo? be w\nd 9 ! same direction ) ,no4 #be s+le cotton cov]$ wire4 ,! wire %\ld be w\nd 9 smoo?1 ev5 lay]s & ! t]m9als l$ out ?r\gh two small holes 9 ! fibre heads4 99,! ,s\nd] ,armature99 is a piece ( /eel or iron rod1 five-sixte5?s ( an in* squ>e & ?ree & ?ree-eigh?s in*es long4 ,x s]ves bo? z ! armature & ! s\nd] lev]4 ,! exact location ( ! holes is %[n 9 ,figure #hf4 ,! holes h & i %\ld be tapp$ to receive an #h-cb screw4 ,! hole j %\ld pass a screw ( ! same size4 ,?is screw s]ves z ! pivot = ! armature4 ,figure #hg %[s h[ ! s\nd] frame %\ld appe> :5 ! lev] is 9 position4 ,! screw ,a controls ! di/ance :i* ! armature moves on its upw>d /roke4 ,! screw ,b /rikes ! anvil on ! d[nw>d /roke & controls ! di/ance betwe5 ! armature & ! electro-magnets4 ,illu/ration3 ,,fig4 #hh4--,top ,view ( ,complet$ ,in/rum5t ,! armature is pu%$ upw>ds & held away f ! magnets aga9/ ! screw ,a by a small spiral spr+4 ,! l[] end ( ! spr+ sets 9 ! hole ,c 9 ! s\nd] frame & ! upp] end re/s aga9/ ! end ( ! screw ,c s t ! t5sion ( ! spr+ c be regulat$ by mov+ ! screw up & d[n4 ,! armature %\ld be free to move up & d[n on ! pivot screw b %\ld n move sideways4 99,! ,base99 ( ! in/rum5t is a rectangul> piece ( h>dwood1 f\r & "o-half in*es long1 ?ree & ?ree-qu>t] in*es wide & "o-half in* ?ick4 ,! s\nd] is m\nt$ on ! base 9 ! position %[n 9 ,figure #hh1 :i* is a top view ( ! complete in/rum5t4 ,two long #h-cb ma*9e screws pass upw>ds ?r\gh ! wood5 base1 ?r\gh ! holes e & f 9 ! s\nd] frame & into ! bottom ( ! magnets1 ?us s]v+ n only to hold ! magnets 9 position b also ! s\nd] frame to ! base4 ,illu/ration3 ,,fig4 #hi4--,side ,view ( ,key4 ,figure #hi is a side view ( ! complet$ key4 ,! key lev] & ! circuit clos+ lev] are illu/rat$ 9 ,figure #ij4 ,! lev] is f\r & ?ree-eigh?s in*es long & five-sixte5?s ( an in* wide4 ,x %\ld be made f spr+ brass4 ,! circuit clos+ lev] is a /rip ( brass ( ! same wid?4 ,all ! holes 9 bo? lev]s1 ) ! exception ( ! c5tre hole 9 ! key lev] %\ld be l>ge en\gh to pass an #h-cb screw4 ,! c5tre hole %\ld be tapp$ to receive an #h-cb screw4 ,! key lev] is fa/5$ to ! frame by means ( a r\nd head$ #h-cb ma*9e screw4 ,! screw %\ld be tight5$ s t ! lev] _c move f side to side4 ,! circuit clos+ lev] is pivot$ to ! back end s t x c sw+4 ,! key lev] %\ld be fitt$ ) a regul> key knob & ! circuit clos+ lev] ) a small knob su* z is g5]ally us$ = ! purpose4 ,bo? ( ^! /yles ( knobs c be pur*as$ f almo/ any electrical supply h\se4 ,! contact po9ts are be/ made ( silv]4 ,silv] makes a bett] contact metal ?an almo/ any?+ else1 ) ! exception ( plat9um4 ,if silv] _c be obta9$ a piece ( l>ge g]man-silv] wire may be us$4 ,illu/ration3 ,,fig4 #ij4--,key & ,circuit ,clos+ ,lev]s4 ,"o contact is sold]$ to ! "u side ( ! key lev]4 ,! o!r contact %\ld be m\nt$ on ! head ( a screw & pass ?r\gh a hole 9 ! iron key frame & ?r\gh ! wood5 base und]nea?4 ,?is l[] contact %\ld be directly und]nea? ! upp] contact & be ?or\ghly insulat$ f ! base4 ,sev]al ?icknesses ( well %ellac$ pap] w =m a fir/ class insulat+ m$ium4 ,! l5g? ( ! contacts %\ld be su* t !re is a di/ance ( ab\t #c-cb ( an in* betwe5 !m :5 ! lev] is horizontal4 ,! circuit clos+ lev] %\ld make contact ) a small /rip ( spr+ brass "u ! l[] contact po9t s t ! contact is connect$ to ! frame ( ! key ?r\gh ! circuit clos+ lev] :5 ! latt] is clos$4 ,! adju/m5t screw on ! key frame is us$ to regulate ! upw>d /roke ( ! key lev]4 ,! adju/m5t screw on ! key lev] is us$ to regulate ! spr+ t5sion ( ! lev]4 ,! l[] end re/s aga9/ ! top ( a small spiral spr+ made ( brass wire4 ,illu/ration3 ,,fig4 #ia4--;,am]ican ,morse ,code4 ,connect+ ! outfit is a v simple mat]4 ,! two inside t]m9als ( ! s\nd] magnets %\ld be connect$ toge!r4 ,"o ( ! outside t]m9als is l$ to a b9d+ po/ m\nt$ on ! back ( ! base4 ,! o!r t]m9al is connect$ to ! l[] key contact4 ,! frame ( ! key is connect$ to a second b9d+ po/ at ! back ( ! base4 ,! connect+ wires %\ld pass ?r\gh small holes & along ! "u side ( ! base4 ,! ,morse ,telegraph ,code is %[n 9 ,figure #ia4 ,a s+le dry cell w provide suffici5t curr5t = practis+ ! ,code4 ,! cell %\ld be connect$ to ! two b9d+ po/s & ! circuit clos+ lev] %\ld be kept op5 at all times or ! batt]y w become exhau/$4 ,illu/ration3 ,,fig4 #ib4--;,circuit = ,two ,in/rum5ts4 ,! numb] ( batt]ies requir$ on a long l9e w dep5d ^u ! resi/ance ( ! l9e & _c easily be pre-det]m9$4 ,figure #ib %[s a circuit = connect+ two in/rum5ts on a l9e4 ,:5 ! d\ble contact swit* is on po9t ,a ! batt]ies are out ( circuit4 ,?r[+ ! swit* on ,b puts ! batt]ies into circuit4 ,!y %\ld be kept out ( circuit :5 ! /ations are n 9 use4 ,! circuit clos] at ,/ation #a mu/ be kept clos$ :5 ,/ation #b is telegraph+ & vice v]sa4 ,,*apt] ,,ix4 ,,h[ ,,to ,,make ,,& ,,in/all ,a ,,telephone4 ,n _m ye>s ago1 ! telephone 0 ! wond] ( ! times j z ! a]oplane & ! wireless are to-day4 ,! orig9al telephone app>atus 0 an exce$+ly crude & simple arrangem5t :i* has gradually develop$ into a wond]ful & complex sy/em :i* makes x possible to c>ry on a conv]sation ) almo/ any o!r po9t 9 ! ,unit$ ,/ates z easily z x is face to face4 ,illu/ration3 ,,fig4 #ic4--,! ,wood5 ,back = ! ,telephone4 ,_m ( my "y read]s h und\bt$ly already con/ruct$ a set ( telegraph in/rum5ts & rigg$ up a l9e ) "s ne>by *um4 ,l ! telegraph1 ! pr9ciple ( ! telephone is t ( a curr5t ( electricity fl[+ ov] a l9e wire into a pair ( electro-magnets1 & x is n any m difficult to in/all a %ort telephone l9e ?an a telegraph4 ,( c\rse !re are _m important diff]5ces betwe5 a telephone & a telegraph b !y are n intricate or complex4 ,! telephone is exce$+ly s5sitive :5 comp>$ to ! telegraph4 ,an ord9>y telegraph relay requires ab\t "o hundr$? ( an amp]e to op]ate x1 :]eas a telephone receiv] w produce an audible s\nd on a curr5t ( less ?an "o million? ( an amp]e4 ,illu/ration3 ,,fig4 #id4--,! ,complete ,telephone4 ,! telephone may be def9$ z an app>atus = transmitt+ spee* to a di/ance by means ( electricity4 ,! "p ( ! app>atus :i* takes up ! s\nds & *anges !m into electric curr5ts is ! transmitt]4 ,:]e words are spok5 into ! m\?-piece ( ! transmitt]1 !y /rike a ?9 metal diaphragm1 to ! back ( :i* is fa/5$ a small cup-%ap$ piece ( c>bon4 ,a second cup is m\nt$ 9 a rigid position directly back ( ! fir/ & ! space betwe5 is fill$ ) small poli%$ granules ( c>bon4 ,:5 ! granules are undi/urb$ & are ly+ loosely toge!r _! resi/ance to an electric curr5t is s great t !y all[ almo/ none to fl[4 ,:5 ! vibrations ( ! voice /rike ! diaphragm !y move x back & =? & cause ! c>bon cup m\nt$ on its back to move & ex]t a v>y+ pressure on ! granules4 ,:5 ! granules are compress$ _! resi/ance is greatly l[]$ & !y p]mit curr5t to pass4 ,t "p ( ! app>atus :i* trans=ms ! pulsat+ curr5t back into s\nd waves is call$ ! receiv]4 ,x consi/s ( a ?9 iron disk1 plac$ v ne> b n q t\*+ ! end ( a small p]man5t magnet ab\t :i* is w\nd a coil ( f9e insulat$ wire4 ,illu/ration3 ,,fig4 #ie4--;,details ( ! ,receiv] ,hook4 ,if ! transmitt] & receiv] are connect$ toge!r 9 s]ies ) a batt]y & words are spok5 into ! transmitt]1 ! little c>bon granules are imm$iately ?r[n into motion1 & be+ alt]nately compress$ & releas$ cause correspond+ *anges 9 ! curr5t fl[+ ?r\gh ! receiv] f ! batt]y4 ,! /r5g? ( ! magnetic pull ex]t$ by ! comb9$ p]man5t magnet & coil ( wire v>ies ) ea* *ange 9 ! electric curr5t & ?us by alt]nately attract+ & repell+ ! diaphragm causes x to vibrate & emit s\nds4 ,?is is ! g5]al pr9ciple ( ! telephone4 ,! telephones 9 actual s]vice to-day are complicat$ ) bells1 induction coils1 cond5s]s & relays1 :i* r5d] !m m effici5t1 b ! g5]al pr9ciple ( ! transmission ( ! spee* is ! same4 ,i w\ld n advise ! "y exp]im5t] to attempt to build 8 own transmitt] & receiv] except = ! k & exp]i5ce ga9$ !reby4 ,homemade in/rum5ts ( ?is sort are n likely to prove s5sitive en\gh = practical purposes ov] a long l9e4 ,a fir/ class telephone receiv] c be pur*as$ = #ij c5ts & an equally good transmitt] = #b4be ,^!1 toge!r ) an ord9>y electric bell c be built into a fir/ class telephone in/rum5t :i* w give excell5t s]vice ov] a long l9e4 ,illu/ration3 ,,fig4 #if4--,%[+ h[ ! ,pu% ,button is arrang$4 ,any boys c easily build & in/all su* an arrangem5t4 ,:5 complet$ x w prove invaluable z a s\rce ( communication f "o "p ( ! h\se to ano!r1 f ! h\se to ! b>n or betwe5 two *ums liv+ 9 ! same neighborhood4 ,figure #ic %[s ! wood5 back ( ! in/rum5t4 ,x is made f a piece ( bo>d #ab in*es long & #g in*es wide1 by cutt+ into ! %ape %[n4 ,?is back s]ves to m\nt ! transmitt]1 receiv]1 bell1 etc4 99,! ,bell99 is = ! purpose ( giv+ an audible signal s t ! p]son he>+ x w "k t "s "o at ! o!r end ( ! l9e wi%es1 to talk4 ,figure #id is a front view ( ! complet$ in/rum5t4 ,! bell is m\nt$ on ! upp] "p ( ! back z %[n 9 ! illu/ration4 99,! ,receiv] ,hook99 is %[n 9 detail 9 ,figure #ie4 ,x %\ld be cut out ( heavy %eet brass & f9i%$ 9 ! %ape %[n4 ,! receiv] hook is m\nt$ directly "u ! bell z %[n 9 ,figure #id4 ,! hook %\ld project out to ! left beyond ! edge ( ! back4 ,! hook is m\nt$ by a r\nd head$ brass screw pass+ ?r\gh ! hole 9 ! "r h& end4 ,illu/ration3 ,,fig4 #ig4--;,circuit %[+ h[ to connect two ,telephone ,/ations to ! ,l9e4 ,! hook %\ld move freely up & d[n betwe5 two contacts 7m>k$ #a & #b 9 ,figure #id74 ,^! contacts are simply two small brass /rips b5t at "r angles & fa/5$ ab\t an in* ap>t along ! left h& edge ( ! wood5 back by means ( two small r\nd head$ brass wood screws4 ,! position ( ! contacts %\ld be su* t ! hook is 9 a horizontal position :5 x is half way betwe5 ! two4 ,a small spr+ is arrang$ s z to pull ! hook up aga9/ ! upp] contact 7,no4 #a7 :5 ! receiv] is lift$ (f4 ,:5 ! receiv] is hung on ! hook1 x %\ld ov]come ! lift ( ! spr+ & pull ! hook d[n aga9/ ! l[] contact 7,no4 #b74 99,! ,receiv]99 may be pur*as$ at almo/ any reliable electrical supply h\se4 ,x %\ld be provid$ ) a r+ s t x c be hung onto ! hook4 99,! ,transmitt]99 is pref]ably ( ! solid back long di/ance type4 ,x also c be pur*as$ ready made f almo/ any electrical supply h\se4 ,! transmitt] is m\nt$ on ! wood5 back directly "u ! hook4 ,x is m>k$ ,t 9 ,figure #id4 99,a ,pu% ,button991 made out ( two r\nd head$ brass wood screws & a /rip ( spr+ brass z %[n 9 ,figure #if1 is m\nt$ to ! "r ( ! transmitt]4 ,"o end ( ! spr+ is fa/5$ d[n firmly ) a screw1 ! o!r end is b5t s t x is directly ov] b does n t\* ! second screw m\nt$ ab\t sev5-eigh?s ( an in* away4 ,f\r b9d+ po/s %\ld be arrang$ along ! bottom ( ! wood5 back & two m j to ! left ( ! transmitt]4 ,! set is n[ ready to wire or connect4 ,! connections c be und]/ood be/ by foll[+ ! diagrams 9 ,figures #id & #ig4 ,/>t+ ) ! f\r b9d+ po/s along ! bottom ( ! back1 m>k ! left h& "o ,b#a1 m>k ! next "o ,b#b1 ! ?ird ,e & ! f\r? ,l4 ,connect a wire f b9d+ po/ ,b#a to ! po/ ,p#a directly above x4 ,run ! wire f ,p#a to ! brass /rip on ! pu% button4 ,connect b9d+ po/s ,b#b & ,e toge!r & f ,e run a wire to ! "r h& b9d+ po/ on ! bell4 ,connect a wire f ! left h& po/ on ! bell to ! l[] contact #b4 ,! hook %\ld be connect$ to b9d+ po/ ,l4 ,! upp] contact #a is connect$ to "o t]m9al ( ! transmitt]4 ,! o!r t]m9al ( ! transmitt] goes to b9d+ po/ ,p#b4 ,! telephone receiv] %\ld be connect$ to ! po/s ,p#a & ,p#b by means1 ( flexible wire4 ,! contact on ! pu% button %\ld be connect$ to ! upp] hook contact #a4 ,! set is n[ complete1 ready to connect to a simil> outfit4 ,! batt]y is connect$ to ! b9d+ po/s m>k$ ,b#a & ,b#b4 ,e & ,l are ! l9e po/s to :i* ! wires connect+ ! two sets are l$4 ,! wire connect+ ! two outfits %\ld n be small] ?an ,no4 #ah ,b4 ,s4 gauge4 ,no4 #ad w prove bett] if ! l9e is a long "o4 ,! wire %\ld be v c>efully insulat$4 ,ord9>y porcela9 knobs w s]ve z suitable insulators4 ,if desirable1 only "o wire ne$ be us$1 ! circuit be+ complet$ by connect+ ! po/ ,e on ea* in/rum5t to ! gr\nd or e>?4 ,! gas or wat] pipes w =m ! mo/ suitable gr\nd connection4 ,! numb] ( batt]ies requir$ w dep5d ^u ! l5g? ( ! l9e4 ,! actual numb] necess>y to r+ ! bell prop]ly c be be/ asc]ta9$ by exp]im5t4 ,x %\ld be notic$ t ! batt]y connections at ea* /ation are rev]s$ s t ! batt]ies w be s]ies4 ,! negative ( ! batt]y at "o /ation is connect$ to ,e & ! positive pole ( ! o!r batt]y at ! o!r /ation to ! simil> po/4 ,:5 ! /ations are n 9 use ! receiv]s %\ld be left hang+ on ! hooks4 ,9 ord] to call ! o!r /ation1 lift ! receiv] (f ! hook4 ,?is ?r[s ! transmitt]1 receiv] & batt]y into ! circuit4 ,! resi/ance ( ! receiv] & transmitt]1 h[ev]1 are s great t !y w prev5t en\gh curr5t f fl[+ to r+ ! bell at ! o!r /ation4 ,press+ ! pu% button w %ort circuit ! transmitt] & receiv] & all[ en\gh curr5t to fl[ to r+ ! bell at ! o!r /ation4 ,! o!r p]son has m]ely to lift up 8 receiv] 9 ord] t ! two p>ties may talk back & =?4 ,:5 ! receiv]s are on ! hooks bo? bells are 9 circuit ready = ei!r p>ty to call up4 ,,*apt] ,x4 ,,m$ical ,,coils ,,& ,,%ock+ ,,coils4 ,m$ical coils & %ock+ coils are ! same4 ,! t]m %ock+ coil is usually appli$ to ! l[ pric$ m$ical coils :i* mo/ boys are famili> ) = giv+ %ocks4 ,illu/ration3 ,,fig4 #ih4--;,bobb9 = ,m$ical ,coil4 ,a m$ical coil is no?+ m or less ?an a small induction coil = rais+ ! voltage ( a batt]y high en\gh to produce a %ock4 ,! human body possesses s mu* resi/ance t ! voltage ( "o or two cells ( ord9>y batt]y is n suffici5t to pass en\gh curr5t ?r\gh to be felt except "u exceptional conditions1 z = in/ance :5 contact is made directly ) a n]ve ?r\gh an op5 cut or a metal fill+ 9 a too?4 ,a small la! w be ( mu* assi/ance 9 mak+ "s ( ! p>ts & fitt+s = ! m$ical coil1 al?\gh x is n absolutely ess5tial & ! +5i\s "y exp]im5t] c und\bt$ly f9d "s me?od ( do+ )\t x4 ,x is n necess>y to foll[ ! dim5sions giv5 "h exactly1 & a v good coil c be built by adapt+ spools1 b9d+ po/s1 etc41 :i* may already be on h&1 al?\gh1 ( c\rse1 !y %\ld be us$ ) "s s5se ( proportion 9 m9d s t no?+ is c>ri$ to an extreme4 ,! fir/ "p :i* w be requir$ is ! bobb94 ,?is is %[n 9 ,fig4 #ih & consi/s ( a wood5 spool1 two & sev5-sixte5? in*es long & "o in* 9 diamet]4 ,x has a ?ree-eigh?s in* hole runn+ all ! way ?r\gh ! c5t]4 ,! dim5sions ( ! flanges1 etc41 c probably be be/ und]/ood by ref]r+ directly to ! illu/ration4 ,! flanges are flatt5$ slightly on "o side s t :5 ! bobb9 is m\nt$ ! flat portion w re/ on ! base & give a bett] support4 ,illu/ration3 ,,fig4 #ii4--;,bobb9 ) ,w9d+4 99,! ,prim>y ,w9d+99 consi/s ( two lay]s ( ,no4 #bd ,b4 ,s4 ,gauge s+le cotton cov]$ wire4 ,! t]m9als ( ! w9d+ %\ld be l$ out ?r\gh two small holes 9 ! "r h& head ( ! bobb94 ,cov] ! w9d+ ) two or ?ree lay]s ( ?9 %ellac$ pap] & !n w9d on ! second>y4 ,! second>y is compos$ ( t5 lay]s ( ,no4 #cf ,b4 ,s4 ,gauge s+le cotton cov]$ wire4 ,! inside end ( ! second>y %\ld be connect$ to ! outside end ( ! prim>y4 ,! outside t]m9al is l$ out ?r\gh a small hole 9 ! head at ! opposite end f ! prim>y leads4 ,! wire on bo? ! prim>y & second>y %\ld be w\nd on 9 smoo? ev5 lay]s4 ,! illu/ration 9 ,figure #ii %[s ! bobb9 aft] ! w9d+s are f9i%$4 99,! ,core99 is made out ( ?9 %eet iron roll$ up into a cyl9d] two & ?ree-sixte5?s in*es long & n9e-?irty-seconds in*es 9 diamet]4 ,! core %\ld be roll$ up j z tightly z possibly1 because ! m iron !re is 9 ! core1 )9 ( c\rse reasonable limit1 ! bett] ! coil w "w4 ,?9 t9 plat$ iron cut f a crack] box may be us$ = ! core4 ,! ?9n] x is ! bett]4 ,a core ( ?is sort1 roll$ up out ( %eet iron w give mu* bett] results ?an a core compos$ ( a solid b> ( iron4 ,illu/ration3 ,,fig4 #ajj4--;,con/ruction ( ! ,core4 ,! end ( ! core is slipp$ into an iron core cap4 ,?is is %[n 9 ,figure #aja4 ,x consi/s ( a small cyl9d]1 sev5-sixte5?s ( an in* 9 l5g?1 cut f a piece ( iron rod1 ?ree-eigh?s ( an in* 9 diamet]4 ,a hole n9e-?irty-seconds ( an in* 9 diamet] & five-sixte5?s ( an in* deep %\ld be drill$ 9 "o end4 ,?is cap is slipp$ ov] "o end ( ! core4 ,x %\ld fit v tightly s t x w n pull out4 ,! core is !n slipp$ into ! bobb9 ) ! outside end ( ! core cap project+ ab\t "o-sixte5? ( an in* out ( ! end at :i* ! prim>y t]m9als lead out4 ,! cap %\ld fit into ! bobb9 v snugly s t ! core is held firmly 9 place4 ,s9ce ! hole ?r\gh ! bobb9 is ?ree-eigh?s ( an in* 9 diamet] & ! core is only n9e-?irty-seconds ( an in* 9 diamet] !re %\ld be a space all ar\nd ! core1 except at ! end :]e ! cap is1 s t a ?9 brass regulator tube c be slipp$ 9 & out ov] ! tube4 ,illu/ration3 ,,fig4 #aja4--,vibrator ,p>ts & ,core ,cap4 99,! ,regulator ,tube99 %\ld be two & sev5-sixte5?s in*es long & h an inside diamet] ( five-sixte5?s ( an in*4 ,9 case ! exp]im5t] has any difficulty 9 secur+ a tube ( ?is size he c easily make "o by roll+ a piece ( %eet brass ar\nd a suitable siz$ rod & sold]+ ! edges4 ,:5 ! tube is slipp$ ov] ! core & mov$ 9 & out ( ! bobb91 aft] ! coil has be5 f9i%$ & set 9 op]ation1 x w regulate ! /r5g? ( ! second>y or %ock+ curr5t4 ,:5 ! tube is completely out ( ! bobb91 ! curr5t w be ! /ronge/4 ,if a pap] scale1 divid$ into sixte5?s ( an in* & be>+ numb]s1 is pa/$ ar\nd ! tube x w act z an indicator ( ! curr5t /r5g?4 ,! base is wood & measures f\r & five-eigh?s in*es long1 two & ?ree-qu>t]s in*es wide & is "o-half an in* ?ick4 ,! prop] location ( ! v>i\s holes c be f\nd by ref]r+ to ! illu/ration 9 ,figure #ajc4 ,! corn]s ( ! base %\ld be slightly r\nd$ s z to improve ! appe>ance4 ,figure #ajd is a top view ( ! coil aft] x has be5 assembl$4 ,! bobb9 is m\nt$ a little back ( ! c5tre ( ! base s t ! core cap w be opposite ! armature ( ! vibrator4 ,illu/ration3 ,,fig4 #ajb4--,regulator ,tube4 99,! ,vibrator ,p>ts99 are illu/rat$ 9 ,figures #aja & #ajf4 ,! vibrator spr+ is a piece ( ?9 /eel or phosphor bronze1 "o-qu>t] ( an in* wide & "o & ?ree-sixte5?s in*es long4 ,a s(t iron armature1 five-sixte5?s ( an in* 9 diamet] & "o-eigh? ( an in* ?ick is fa/5$ to "o end ( ! spr+4 ,a five-?irty-seconds in* hole is drill$ 9 ! o!r end & x is !n m\nt$ 9 ! vibrator po/s4 ,?is consi/s ( a small brass pill>1 "o-qu>t] ( an in* 9 diamet] & five-eigh?s ( an in* long4 ,! l[] end is drill$1 & tapp$ to receive a #d-cf screw :i* fa/5s x to ! base4 ,a saw slot "o-qu>t] ( an in* deep is made 9 ! top to receive ! vibrator spr+4 ,! po/ :i* holds ! adju/m5t screw is id5tical ) t :i* supports ! vibrator spr+1 except t a ?read$ hole is drill$ ?r\gh ! saw slot1 fifte5-?irty-seconds ( an in* f ! bottom1 ?r\gh :i* ! screw passes4 ,! end ( ! adju/m5t screw1 :i* may be an ord9>y knurl$ ?umbscrew f a b9d+ po/1 %\ld be fitt$ ) a contact po9t4 ,! be/ contact po9t is a piece ( plat9um1 b a small piece ( silv] c be made to s]ve ! purpose v well4 ,illu/ration3 ,,fig4 #ajc4--,! ,base ) ,location ( ,holes4 ,illu/ration3 ,,fig4 #ajd4--,top ,view ( ,f9i%$ ,coil4 ,! vibrator spr+ %\ld also be fitt$ ) a simil> contact po9t4 ,illu/ration3 ,,fig4 #aje4--,side ,view ( ,complet$ ,coil4 ,! m$ical coil is v easy to connect4 ,run ! inside prim>y t]m9al to ! b9d+ po/ on ! re> left h& corn] ( ! base4 ,connect ! o!r t]m9al to ! vibrator po/4 ,a wire %\ld be l$ f ! adju/m5t screw po/ to ! b9d+ po/ m\nt$ on ! =w>d left h& corn] ( ! base4 ,illu/ration3 ,,fig4 #ajf4--,vibrator ,p>ts4 ,"o or two cells ( batt]y %\ld be suffici5t to op]ate ! coil4 ,connect ! batt]y to ! two b9d+ po/s4 ,adju/ ! ?umbscrew until ! contact on ! end j t\*es ! contact po9t on ! vibrator spr+4 ,! curr5t w !n fl[ ?r\gh ! prim>y w9d+ & magnetize ! core4 ,! magnetism ( ! core w draw ! armature t[>ds x1 ?us pull+ ! contacts ap>t & int]rupt+ ! curr5t4 ,! process w repeat itself v rapidly at a spe$ dep5d+ ^u ! adju/m5t ( ! ?umbscrew & z long z ! batt]y rema9s connect$4 ,illu/ration3 ,,figs4 #ajg & #ajh4--,two ,types ( ,h&les4 ,! h&les = ! coil are v easily made out ( a piece ( brass tub+ ab\t two & "o-half in*es long & five-eigh?s ( an in* 9 diamet]4 ,!y c also be made by roll+ a piece ( %eet brass or t9 into a tube & sold]+ ! edges toge!r4 ,! illu/ration %[s two me?ods ( mak+ ! h&les & atta*+ ! cords4 ,! h&le 9 ! upp] "p ( ! illu/ration is made f a piece ( tub+4 ,a wood5 plug or cork is fitt$ into "o end4 ,! wire passes ?r\gh a hole 9 ! c5tre ( ! plug & is turn$ back ov] ! edge s t :5 ! plug is =c$ into ! tube1 ! wire w make contact ) x4 ,! h&le 9 ! l[] "p ( ! illu/ration is made f "o ( ! brass cyl9d]s 9 :i* ! indelible ink = rubb] /amps is suppli$4 ,a hole is bor$ 9 ! bottom ?r\gh :i* ! wire passes4 ,! end ( ! wire is sold]$ to a piece ( /iff brass wire b5t into ! %ape ( a hairp94 ,! ends ( ! wire are spread ap>t s t !y w spr+ aga9/ ! inside ( ! tube4 ,! connector is !n pull$ up inside ( ! h&le4 ,! flexible wires or cords z !y are sometimes call$1 atta*$ to ! h&les1 %\ld be ab\t eighte5 in*es long4 ,! opposite ends to ! h&les %\ld be l$ ?r\gh two holes 9 ! base1 9 front ( ! bobb94 ,! left h& cord %\ld be connect$ to ! vibrator po/ & ! "r h& cord to ! outside second>y t]m9al4 ,! coil is n[ complete1 ready = op]ation4 ,connect ! batt]y to ! b9d+ po/s4 ,/>t ! int]rupt] & grasp "o ( ! h&les 9 ea* h&4 ,draw ! regulator tube out ( ! bobb9 gradually & ! curr5t w gradually gr[ /rong] & /rong] until x is impossible to hold ! h&les4 ,:5 ! regulator tube is all ! way 9 ! bobb9 x is practically impossible to feel ! curr5t4 ,( c\rse any int]m$iate /r5g? betwe5 ! two extremes c easily be secur$4 ,! %ock f ! coil is h>mless4 ,:5 ! regulator is all ! way out1 ! %ock is v /rong4 ,! only result1 h[ev]1 is to make ! p]son receiv+ x drop ! h&les4 ,! curr5t f m$ical coils is (t5 prescrib$ by physicians = rheumatism & n]v\s disord]s1 b x mu/ be prop]ly appli$ 9 ord] to be ( b5efit4 ,,*apt] ,,xi4 ,,! ,,con/ruction ,,( ,,sp>k ,,coils4 ,a ,sp>k ,coil is "o ( ! mo/ int]e/+ pieces ( app>atus t an exp]im5t] c possess4 ,n only c x be us$ to transmit wireless messages1 b num]\s & v>i\s exp]im5ts may be p]=m$ ) its aid4 ,! purpose ( a sp>k coil is to g5]ate enorm\sly high voltages :i* are able to s5d sp>ks across an air space :i* ord9>y batt]y curr5ts ( l[ voltage c\ld n possibly pi]ce4 ,illu/ration3 ,,fig4 #aji4--;,induction or ,sp>k ,coil4 ,x consi/s ( an iron core surr\nd$ by a coil ( heavy wire kn[n z ! prim>y & a second outside w9d+ ( f9] wire kn[n z ! second>y4 ,! prim>y is connect$ to a few cells ( dry batt]y 9 s]ies ) an int]rupt]4 ,e "t t ! int]rupt] %uts (f ! batt]y curr5t 9 ! prim>y1 curr5ts are induc$ 9 ! second>y :i* are ( suffici5tly high voltage or pressure to leap across a space 9 ! %ape ( sp>ks4 ,a sp>k coil is n v h>d to con/ruct1 b x requires c>eful workman%ip & pati5ce4 ,x is n usually a job :i* c be f9i%$ 9 a day1 b w take q a little "t1 especially 9 w9d+ ! second>y4 ,9 describ+ ! con/ruction ( a sp>k coil 9 ?is *apt]1 directions & dim5sions h be5 giv5 = a "o-qu>t] in* coil4 ,! g5]al me?od ( proc$ure is ! same = all sizes ( coils1 ! dim5sions only1 are diff]5t4 ,! exp]im5t] may !re=e easily build a l>g] coil ?an ! "o-qu>t] in* by consult+ ! tables ( dim5sions4 ,p>ts = sp>k coils are = sale by _m electrical h\ses & x is possible to pur*ase ! complete p>ts = less ?an ! sep>ate mat]ials w\ld co/4 ,su* p>ts are made by special ma*9]y & !re=e are produc$ q *eaply4 ,! ,core is made ( s(t iron core wire ab\t ,no4 #bj or #bb ,b4 ,s4 ,gauge4 ,ea* piece %\ld be f\r & ?ree-qu>t]s in*es long4 ,iron wire may be b\ght already cut to l5g? f v>i\s h\ses deal+ 9 exp]im5t]'s supplies4 ,consid]+ ! am\nt ( labor t is requir$ to cut ea* piece to l5g? arid !n /raight5 x out1 x is *eap] to pur*ase ! wire already cut4 ,illu/ration3 ,,fig4 #aaj4--,! ,prim>y & ,core4 ,size ( ,coil4 ,o ,l5g? ( ,p ,diamet] ( ,prim>y ,wire ,core ,core #a_/d in* #d #c_/d in*es #a_/b in* #ah ,b4 ,s4 #a_/b in* #e in*es #e_/h in* #ah ,b4 ,s4 #a in* #g in*es #e_/h in* #ah ,b4 ,s4 ,core wire is a special grade ( wire :i* is v s(t & has be5 anneal$4 ,if ord9>y iron wire is us$ 9 mak+ a core1 x mu/ fir/ be anneal$4 ,?is is accompli%$ by ty+ ! wire 9 a compact bundle & plac+ x 9 a wood fire until x is r$ hot4 ,aft] ! wire is hot1 cov] x ) a%es & all[ ! fire to die away4 ,:5 ! fire has gone out & ! wire has cool$ ! anneal+ process is complete4 ,en\gh wires ea* f\r & ?ree-qu>t]s in*es long to =m a compact bundle "o-half in* 9 diamet] w be requir$4 ,illu/ration3 ,,fig4 #aaa4--,! ,second>y ,w9d+4 ,l ,size ,l ,l5g? ( ,m ,no4 ( ,m ,size ,no4 ( ,turns ,wire ( ,coil ,second>y ,sections ( ,hole p] ,section #a_/d 94 #b #c_/h 94 #a #a #a_/ah #e1jjj #cg 94 en4 #a_/b 94 #b #c_/h 94 #a #a #a_/h #aj1jjj #cg 94 en4 #a 94 #b #b_/h 94 #a #a #a_/h #aj1jjj #cg 94 en4 ,!re are two sections ( second>y us$ on ! #a-;in* coils4 ,cut a piece ( t\gh wrapp+ pap] ab\t six in*es long & f\r & "o-half in*es wide4 ,roll x up 9 ! =m ( a tube s t x is six in*es long & "o-half in* 9 diamet] inside4 ,glue ! inside & outside edges ( ! pap] s t ! tube _c unroll & !n slip ! core wires into x until ! tube is pack$ tightly & no m c be slipp$ 94 ,! core is n[ ready = ! prim>y1 :i* consi/s ( two lay]s ( ,no4 #ah ,b4 ,s4 ,gauge cotton cov]$ wire w\nd ov] ! core = a di/ance ( ?ree & ?ree-qu>t]s in*es4 ,! w9d+ %\ld />t five-eigh?s ( an in* f "o end ( ! core4 ,! wire mu/ be w\nd v smoo?ly & c>efully4 ,! inside end ( ! wire c be fa/5$ s t x w n become loose by plac+ a %ort piece ( tape l5g?wise ( ! core & w9d+ two or ?ree turns ov] x4 ,!n d\ble ! end back & complete ! w9d+ ov] x4 ,! end ( ! wire c be fa/5$ by imb$d+ a piece ( tape "u ! w9d+ ) a small loop project+ & !n pass+ ! wire ?r\gh ! loop4 ,figure #aaj %[s ! complete core ) prim>y w9d+ 9 position4 99,! ,second>y99 is a mu* m t$i\s job ?an ! prim>y & mu/ be v c>efully made4 ,:5ev] x is possible = ! exp]im5t] to pur*ase a second>y already w\nd he is advis$ to d s4 ,! second>y consi/s ( #e1jjj-f1jjj turns ( ,no4 #cg ,b4 ,s4 ,gauge1 enamel$ wire w\nd 9 smoo?1 ev5 lay]s1 ) two lay]s ( pap] betwe5 e two lay]s ( wire4 ,! prim>y w9d+ is wrapp$ ) six lay]s ( empire clo? or pap]4 ,empire clo?s & pap]s are a yell[ insulat+ mat]ial made by treat+ l95 or pap] ) l9se$ oil4 ,roll up a pap] tube ( five or six lay]s ( pap] s t ! f9i%$ tube is two & "o-half in*es long & ( prop] inside diamet] to j slip ov] ! prim>y w9d+ :5 ! empire clo? or pap] is 9 position4 ,! second>y is w\nd ov] ?is pap] tube4 ,x w be necess>y to m\nt ! tube on a r\nd wood5 m&rel fitt$ ) a small crank or h&le s t ! tube may be revolv$4 ,a w9d] may be v easily made by m\nt+ a r\nd wood5 /ick ( ! same diamet] z ! inside ( ! pap] tube 9 a pair ( wood5 supports4 ,bore a hole 9 "o end ( ! /ick & b5d a piece ( /iff wire 9 x s z to =m a crank4 ,illu/ration3 ,,fig4 #aab4--,! ,fix$ ,cond5s]4 ,size ,l5g? ,wid? ,l5g? ,wid? ,no4 ( ,no4 ( ( ( ( ( ( ,pap] ,t9foil ,coil ,pap] ,pap] ,t9foil ,t9foil ,%eets ,%eets #a_/d #cj 94 #d #c_/h #cj 94 #d 94 #e #d 94 94 #a_/b #cj 94 #d #c_/h #cj 94 #d 94 #e #d 94 94 #a 94 #cj 94 #d #c_/h #cj 94 #d 94 #g #f 94 ,! pap] plac$ betwe5 ea* two lay]s ( ! second>y w9d+ %\ld be ! special wax$ pap] :i* is made = t purpose4 ,/>t & end ea* lay] ( wire "o-half in* f ! edges ( ! pap]4 ,w9d ! wire 9 smoo?1 ev5 lay]s1 p]mitt+ ea* turn to t\* ! o!r1 b none to lap ov]4 ,w9d on two lay]s ( wax$ pap] betwe5 ea* lay] ( wire & ! next4 ,! pap] mu/ be put on smoo?ly & ev5ly s z to af=d a firm f\ndation = ! next lay] ( wire4 ,! wire %\ld nev] come ne>] to ! edges ( ! pap] ?an "o-half in* or ! insulation ( ! second>y w be weak & ! coil n liable to give a long sp>k4 ,! utmo/ c>e %\ld be us$ n to break ! wire4 ,if x %\ld break1 ! ends mu/ be v c>efully connect$4 ,! numb] ( turns t ea* lay] av]ages %\ld be c>efully not$ s t by keep+ a record ( ! numb] ( lay]s x is possible to tell h[ _m turns h be5 w\nd on4 ,:5 five to six ?\s& turns h be5 w\nd on ! second>y x is suffici5tly l>ge1 & ! outside end ( ! wire %\ld be fa/5$ & prev5t$ f unw9d+ by secur+ x ) a drop ( seal+ wax4 ,:5 w9d+ a second>y rememb] t if at any po9t 9 ! "w1 y all[ ! w9d+ to become irregul> or unev51 ! irregul>ity w be mu* exagg]at$ on ! succe$+ lay]s4 ,= ?is reason d n all[ any irregul>ities to occur & if ! wire t5ds to g unev5ly1 w9d on two or ?ree extra lay]s ( ! wax$ pap] to smoo? x out4 ,illu/ration3 ,,fig4 #aac4--;,details ( ! ,wood5 ,coil ,heads4 ,size ( ,coil ,d ,k ,j #a_/d 94 #c 94 #b #a_/b 94 #a_/b 94 #a_/b 94 #c 94 #b #a_/b 94 #e_/h 94 #a 94 #c #a_/b 94 #c 94 #e_/h 94 99,! ,cond5s]99 consi/s ( alt]nate lay]s ( t9foil & p>aff9$ pap] pil$ on top ( ea* o!r & !n roll$ up4 ,f\r %eets ( t9foil1 ?irty-six in*es by two & ?ree-qu>t]s in*es wide w be requir$4 ,eight /rips ( wax$ cond5s] pap]1 ?ree & "o-qu>t] in*es wide & ?irty-six in*es long are necess>y4 ,lay "o %eet ( pap] out flat on a table or bo>d & place a %eet ( t9foil ov] x4 ,! t9foil %\ld be along ! c5tre ( ! pap] /rip s t !re is a "o-qu>t] in* pap] m>g9 along ! sides4 ,"o end ( ! t9foil %\ld project ov] ! end ( ! pap] ab\t two in*es4 ,lay two %eets ( wax$ pap] ov] ! t9foil mak+ !m l9e up ) ! fir/ pap] %eet all ar\nd4 ,!n place ano!r /rip ( t9foil on ! pap]4 ,x %\ld be directly above ! fir/ %eet ( t9foil1 b ! end ( ! t9foil mu/ ov]lap ! pap] by two in*es at ! opposite end f ! fir/ %eet4 ,place two m %eets ( pap] ov] ! t9foil & on top ( t a ?ird /rip ( foil4 ,! ?ird /rip ( foil %\ld l9e up exactly ) ! fir/ /rip4 ,!n lay two m %eets ( wax$ pap] ov] ! ?ird %eet ( foil & place ! f\r? %eet ( t9foil 9 position mak+ x exactly l9e up ) ! second %eet4 ,place a s+le %eet ( pap] on top4 ,! result %\ld consi/ ( f\r %eets ( t9foil insulat$ f ea* o!r ) two /rips ( pap] betwe5 ea* two /rips ( foil4 ,connect ! fir/ & ?ird %eets toge!r ) a wire & ! second & f\r? %eets likewise4 ,cut out a piece ( c>dbo>d1 "o & "o-qu>t] in*es wide & ?ree & "o-qu>t] in*es long4 ,lay ! c>dbo>d on "o end ( ! cond5s] & roll ! cond5s] up ar\nd x v tightly4 ,tie x ) a piece ( /r+ to keep x f unroll+1 & dip x 9 "s melt$ p>aff9e4 ,!n place x betwe5 two bo>ds ) a weight on top s z to press x out flat4 99,! ,coil ,heads99 are made f two h>dwood blocks ?ree in*es squ>e & "o-half an in* ?ick4 ,a circul> groove1 two & "o-half in*es 9 diamet] & "o-qu>t] ( an in* deep is turn$ 9 ea* block to receive a c>dbo>d tube ( ! same diamet]4 ,! two upp] corn]s ( ea* ( ! blocks are r\nd$ slightly to improve _! appe>ance4 ,"o ( ! heads has a r\nd hole "o-half in* 9 diamet] bor$ ?r\gh ! c5tre s t "o end ( ! core may be pass$ ?r\gh4 ,! core %\ld project ?r\gh ab\t "o-eigh? ( an in*4 ,! o!r head is bor$ ) a hole ( ! same diamet] b ! hole %\ld n pass all ! way ?r\gh1 & s]ves m]ely to receive & support ! o!r end ( ! core4 ,illu/ration3 ,,fig4 #aad4--;,details ( ! ,wood5 ,base4 ,size ( ,coil ,a ,b ,c #a_/d 94 #h 94 #d 94 #a #a_/h 94 #a_/b 94 #h #a_/d 94 #d #a_/b 94 #a #a_/h 94 #a 94 #aj #a_/d 94 #d #a_/b 94 #a #a_/d 94 99,! ,base99 ( ! coil is a box eight in*es long1 f\r in*es wide & "o & "o-eigh? in*es deep4 ,x is made 9 ! =m ( a holl[ box4 ,give ! base a coat ( /a91 pref]ably "s d>k color1 su* z mahogany1 & !n a coat ( %ellac or v>ni%4 ,! wood5 heads %\ld be /a9$ black4 ,! p>ts ( ! int]rupt] are %[n 9 ,figure #aae4 ,!y _c be made by e exp]im5t] on acc\nt ( ! tools requir$1 b c be pur*as$ v *eaply f conc]ns deal+ 9 mat]ial = exp]im5t]s4 99,! ,/&>d99 is a piece ( hexagonal brass rod "o & ?ree-sixte5?s in*es long & ?ree-eigh?s ( an in* 9 diamet]4 ,! l[] end ( ! /&>d is tapp$ to receive an #h-cb ma*9e screw4 ,a hole is bor$ at "r angles to ! axis ( ! /&>d1 "o in* f ! l[] end & tapp$ to receive an #h-cb ?umbscrew4 ,illu/ration3 ,,fig4 #aae4--;,details ( ! ,int]rupt]4 ,! ,spr+ & ,/&>d = ! ,"o in* coil %\ld be made "o-qu>t] ( an in* long]4 ,! ,?umbscrew %\ld be ab\t sev5-eigh?s ( an in* long & be provid$ ) a lock nut s t x c be fa/5$ 9 position4 ,! end ( ! ?umb-screw is drill$ ) a small hole & a contact po9t driv5 9 tightly4 ,! contact po9t is usually a piece ( plat9um wire1 b 9 ! case ( a small coil may be a piece ( ! special contact wire :i* is sold = j ?is purpose4 ,illu/ration3 ,,fig4 #aaf4--,! tube4 ,size ( ,coil ,l5g? ( ,tube ,diamet] ( ,tube #a_/d in* #d #a_/d in* #b #a_/b in* #a_/b in* #d #a_/b in* #b #a_/b in* #a in* #f #a_/b in* #c in* 99,! ,spr+99 is a piece ( ?9 /eel1 ?ree-eigh?s ( an in* wide & two & "o-eigh? in*es long4 ,sev]al holes are drill$ 9 x4 ,! illu/ration %[s ! exact location ( ^! holes4 ,! holes ,a & ,c %\ld be j l>ge en\gh to all[ an #h-cb ma*9e screw to slip ?r\gh4 ,! hole ,b is j l>ge en\gh to receive a piece ( contact wire4 99,! ,contact99 wire %\ld be ab\t ?ree-?irty-seconds ( an in* long & be slipp$ 9 ! hole & rivet$ 9 place4 99,! ,armature99 is a piece ( s(t iron cut out ( a rod "o-half an in* 9 diamet]4 ,x %\ld be ab\t "o-qu>t] ( an in* ?ick1 b %\ld h a small /ud left on "o face s t ! /ud may be slipp$ into ! hole m>k$ ,c 9 ! /eel spr+ & ! armature !n rivet$ firmly to ! spr+ by flatt5+ out ! /ud4 ,illu/ration3 ,,fig4 #aag4--,! ,bridge4 ,size ( ,coil ,e ,l5g? ,i ,wid? #a_/d in* #d #g_/h in* #c_/d in* #a_/b in* #e #a_/h in* #c_/d in* #a in* #g #a_/h in* #c_/d in* ,! spr+ is b5t at "r angles ab\t "o-half in* f ! end z %[n by ! dott$ l9e 9 ,figure #aae4 99,a ,c>dbo>d ,tube991 two & "o-half in*es 9 diamet] & f\r & "o-qu>t] in*es long1 is us$ to inclose ! prim>y & second>y w9d+s :5 !y are 9 position4 ,! tube may be giv5 a v f9e appe>ance by glu+ a s+le lay] ( black bookb9d]s' clo? ov] x4 99,! ,bridge99 %[n 9 ,figure #aag is a /rip ( wood ab\t "o-eigh? ( an in* ?ick1 f\r & sev5-eigh?s in*es long & ?ree-qu>t]s ( an in* wide4 ,x is /a9$ to mat* ! base & is !n giv5 a coat ( %ellac or v>ni%4 ,two holes are bor$ 91 ! bridge1 "o in* f ea* end4 ,! coil is n[ ready = assembl+4 ,figure #aah4 %[s a cross-section ( ! complete coil4 ,slip ! second>y ov] ! insulat+ clo? or pap] wrapp$ ar\nd ! prim>y4 ,pass "o end ( ! core ?r\gh ! hole 9 ! coil head mak+ sure t ! groove is on ! side t[>ds ! second>y4 ,! second>y %\ld be exactly 9 ! c5tre ( ! prim>y4 ,illu/ration3 ,,fig4 #aah4--,section ( ! ,sp>k ,coil %[+ ! arrangem5t ( ! ,p>ts4 ,slide ! c>dbo>d tube ov] ! prim>y & second>y into ! groove4 ,lead ! second>y t]m9als out ?r\gh small holes 9 ! c>dbo>d tube at opposite ends s t ! wires are sep>at$ z f> z possible4 ,slip ! o!r coil head ov] ! end ( ! core & ! tube & !n m\nt ! coil on ! top ( ! base4 ,! coil %\ld be 9 ! c5tre ( ! base :5 consid]$ f front to back4 ,x %\ld be to ! left ( c5tre1 h[ev]1 :5 view$ f side to side4 ,! two prim>y heads %\ld be f\r in*es ap>t ,:5 ! coil is assembl$4 ,! prim>y wires are l$ d[n close to ! wood5 head & ?r\gh ! base "u ! coil4 ,!y %\ld be kept z f> away f ! second>y z is possible4 ,! coil is fa/5$ to ! base by a wood screw pass+ ?r\gh ! base into ea* ( ! wood5 heads4 ,figure #abb w %[ be/ h[ ! int]rupt] is arrang$4 ,! brass spr+ c>ry+ ! armature at its upp] end is m\nt$ 9 front ( ! core end project+ ?r\gh ! wood5 head4 ,! /&>d c>ry+ ! ?umbscrew & ! lock nut are m\nt$ directly beh9d ! spr+ 9 su* a position t ! contacts t\* ea* o!r & l9e up p]fectly4 ,illu/ration3 ,,fig4 #aai4--;,end ,view ( ! ,complete ,coil4 ,size ( ,coil ,b ,wid? ( ,base ,d ,wid? ( ,head #a_/d in* #d in* #c in* #a_/b in* #d in* #c in* #a in* #d #a_/b in* #c #a_/b in* ,a small brass wa%] is plac$ betwe5 ! /&>d & ! base s t x w n bite into ! wood :5 ! screw is tight5$4 ,! /&>d & ! spr+ are bo? m\nt$ by #h-cb brass ma*9e screws pass+ ?r\gh ! base4 ,two b9d+ po/s are m\nt$ on ! corn]s ( ! base ne> ! int]rupt]4 ,illu/ration3 ,,fig4 #abj4--,side ,view ( ! ,complet$ ,coil4 ,size ( ,a ,c ,d ,e ,f ,g ,h ,q ,coil #a_/d 94 #h 94 #a #c #d #c #a #e_/h #d #a_/h 94 #g_/h 94 #g_/af 94 #a_/d 94 94 94 94 #a_/b 94 #h #a_/d #a #c #e #c #a #e_/h #d 94 #a_/h 94 #a_/h 94 #g_/af 94 #a_/b 94 94 94 94 #a 94 #aj #a #c #g #d #a #e_/h #f #a_/d #a_/d #a_/b #a_/h 94 #g_/af 94 #a_/b 94 94 94 94 94 94 ,! cond5s] is fa/5$ to ! "u side ( ! base by means ( a wood5 /rip pass+ across x & secur$ to ! base by means ( two small wood screws4 ,"o ( ! b9d+ po/s is connect$ to "o ( ! prim>y wires4 ,! o!r prim>y wire is connect$ to ! spr+4 ,! o!r b9d+ po/ is connect$ to ! /&>d4 ,! cond5s] is connect$ directly across ! int]rupt]1 t is1 "o wire is connect$ to ! spr+ & ! o!r wire to ! /&>d4 ,two b9d+ po/s are m\nt$ on ! wood5 bridge & !n ! bridge is fa/5$ across ! top ( ! coil by means ( two brass nails4 ,! second>y t]m9als are connect$ to ^! b9d+ po/s4 ,! ,coil is n[ ready = op]ation4 ,connect two pieces ( wire to ! second>y b9d+ po/s & br+ !m t[>d ea* o!r until !y almo/ t\*4 ,! space betwe5 %\ld be ab\t "o-qu>t] ( an in* long4 ,illu/ration3 ,,fig4 #aba4--;,diagram ( ,connections4 ,connect ?ree or f\r good dry cells to ! prim>y po/s & turn ! ?umbscrew until ! contact po9t on ! end t\*es ! contact on ! spr+4 ,! int]rupt] %\ld imm$iately comm5ce to buzz & if ! coil has be5 prop]ly con/ruct$ & connect$1 a /ream ( sp>ks w jump betwe5 ! wires connect$ to ! second>y4 ,x may be possible t ! action ( ! int]rupt] & consequ5tly ! /r5g? ( ! sp>ks at ! second>y c be improv$ by b5d+ ! spr+' ei!r away or t[>ds ! core4 ,a little exp]im5t+ w soon %[ j h[ mu* t5sion ! spr+ %\ld h4 ,:5 ! prop] position ( ! ?umb-screw is f\nd1 tight5 ! lock nut s t x _c *ange its adju/m5t4 ,illu/ration3 ,,fig4 #abb4--,p]spective view ( ,coil %[+ names ( ! v>i\s p>ts4 ,details & in/ructions = build+ & exp]im5t+ ) l>g] sp>k coils are giv5 9 our books ,exp]im5tal ,wireless ,con/ruction & ,induction ,coils4 ,,exp]im5ts ,,) ,,sp>k ,,coils4 ,exp]im5t #a--;,an ,imitation ,gassiot's ,cascade4 ,wrap a piece ( copp] wire ar\nd a small glass j> & connect x to "o ( ! second>y t]m9als ( ! coil4 ,fill ! j> up ) wat] & dip a wire connect$ to ! o!r second>y t]m9al into ! wat]4 ,if ! coil is !n set into op]ation1 ! entire outside ( ! j> w be cov]$ ) sp>ks />t+ f ! wires & ru%+ upw>ds into ! neck ( ! j>4 ,if ! coil us$ = ?is exp]im5t is a v small "o1 ! glass j> %\ld also be v small1 z = example1 a small m$ic9e vial4 ,?is exp]im5t %[s (f ! be/ :5 p]=m$ 9 ! d>k4 ,exp]im5t #b--;,a ,gho/ly ,light ,grasp ! bulb ( an old inc&esc5t electric light bulb 9 "o h& & t\* ! base ( ! lamp to "o ( ! second>y t]m9als ( ! coil4 ,set ! coil 9 op]ation & ! bulb w gl[ ) a weird gre5i% light4 ,?is exp]im5t w "w be/ 9 ! d>k4 ,exp]im5t #c--,light+ ,geissl] ,tubes4 ,! mo/ beautiful & wond]ful effects may be obta9$ f ,geissl] tubes op]at$ f a sp>k coil 9 a d>k room4 ,^! tubes come 9 an almo/ endless v>iety ( /yles & %apes4 ,!y are exhau/$ ( air & fitt$ ) metallic wires1 seal$ into ! ends1 a portion ( ! wire project+ outside 9 ! =m ( small r+s1 s t ! connections are easily e/abli%$4 ,"s ( ! tubes are ( ord9>y glass1 :ile o!rs are made ( glass hav+ 9 its composition c]ta9 metallic oxides4 ,"s ( ! tubes are fill$ ) v>i\s gases 9 a highly r>ifi$ /ate4 ,o!rs h a d\ble wall ) ! outside fill$ ) a fluoresc5t liquid1 su* z an aque\s solution ( sulphate ( qu99e or an alcoholic solution ( /rammonium1 & o!r comp\nds4 ,! tubes are n v exp5sive4 ,!y c be obta9$ 9 a great v>iety ( sizes4 ,mo/ well /ock$ electrical h\ses c>ry+ goods = ! electrical exp]im5t] h !m on h&4 ,su* tubes are ( necessity v fragile articles & %\ld be h&l$ ) extreme c>e4 ,x is a good plan to keep !m wrapp$ 9 cotton & to put !m away 9 a /rong wood5 box1 s z to r$uce ! dang] ( breakage4 ,! v smalle/ coil1 ev5 ! "o-qu>t] in* size1 w s]ve to light a l>ge tube4 4 ,9 fact1 if too l>ge a coil is us$1 !re is dang] ( spoil+ ! tube4 ,! tubes are connect$ to ! sp>k coil by runn+ a wire f ea* ( ! small r+s at ! ends ( ! tubes to ! second>y t]m9als4 ,sev]al tubes may be connect$ 9 s]ies :5 a or #a-;in* coil is available4 ,to %[ ! be/ effects1 ! room %\ld be 9 p]fect d>kness & ! tubes %\ld be plac$ aga9/ a backgr\nd ( black velvet4 ,exp]im5t #d--;,flick]+ ,light4 ,spread y\r f+]s out & move y\r h& rapidly back & =? ov] a light$ ,geissl] tube 9 a d>k5$ room4 ,y\r h& w appe> to h t5 or twelve f+]s in/ead ( five4 ,?is is due to ! fact t ! light f a ,geissl] tube is flick]+ & n at all /eady4 ,ea* "t ! int]rupt] ( ! coil op5s1 ! curr5t is s5t ?r\gh ! tube & lights x mom5t>ily4 ,! flick]+ is almo/ too rapid to be p]ceiv$ by ! nak$ eye until y h some?+ l ! f+]s or a p5cil 9 front ( x4 ,exp]im5t #e--,rotat+ a ,geissl] ,tube4 ,an extremely pretty effect c be secur$ by rotat+ a ,geissl] tube at high spe$ :ile x is light$4 ,?is may be accompli%$ by means ( an electric motor ( small size4 ,! tube is ti$ tightly to a /ick ( wood :i* has a hole drill$ exactly 9 its c5t] into :i* ! motor %aft fits tightly4 ,two r+s ( metal are m\nt$ on ! motor %aft1 & a wire is l$ f ea* to a t]m9al ( ! tube4 ,a copp] /rip re/s on ea* r+1 & ^! two copp] /rips are connect$ to ! second>y ( ! sp>k coil4 ,:5 ! motor is />t$ & ! coil set into op]ation1 ! tube w appe> l ! spokes ( a :eel4 ,! int]mitt5t light w make ! tube visible = a fraction ( a second 9 v>i\s positions ar\nd ! circle z x rotates1 & ?is gives ! effect :i* is mu* l t ( a p9:eel4 ,exp]im5t #f--;,fluoresc5t ,writ+4 ,dissolve "s sulphate ( qu99e 9 wat] & !n draw a picture or design or write a s5t5ce on a piece ( :ite pap] ) x1 & all[ x to dry4 ,! writ+ w be invisible1 b if y hold x up to a light$ ,geissl] tube 9 a d>k room1 x w appe> z if writt5 ) a beautiful blue ink4 ,exp]im5t #g--;,an ,electric ,bomb4 ,?is is a v int]e/+ exp]im5t f :i* !re is no dang] if x is p]=m$ c>efully4 ,! mort> is no?+ m or less ?an a piece ( wood :i* is h>d & well season$1 & has a small hole bor$ 9 its axis ab\t ?ree-eigh?s ( an in* 9 diamet] & an in* deep4 ,two %ort l5g?s ( /iff copp] wire %\ld be ins]t$ ?r\gh ! sides ne> ! bottom ( ! hole s z to =m a small sp>k gap betwe5 ! ends4 ,put a little gunp[d] 9 ! mort> & connect two wires f ! second>y t]m9als ( ! sp>k coil to ! sp>k gap4 ,place a cork loosely 9 ! muzzle ( ! mort> & !n1 /&+ well away1 close ! swit* 9 ! prim>y circuit ( ! coil1 s t a sp>k passes ?r\gh ! mort>4 ,! sp>k w ignite ! p[d] & x w explode ) a l\d report4 99,caution994--,d n use m ?an a p9* ( p[d] at a "t z ?is is suffici5t to cause a %>p explosion4 ,exp]im5t #h--;,electrify+ ! ,g>bage ,c4 ,if y are ev] annoy$ by dogs or cats t knock ! cov] (f ! g>bage c 9 _! se>* = can9e & fel9e delicacies1 y c give !m ! surprise ( _! lives ) ! aid ( a sp>k coil ^u ! occasion ( _! next visit4 ,set ! c ^u a ?ick piece ( p]fectly dry wood & run a wire f ! c to "o second>y t]m9al ( ! sp>k coil4 ,connect ! o!r second>y t]m9al to ! gr\nd or to a wat] or gas pipe4 ,! next "t y see a dog ) 8 nose 9 ! c1 close ! swit* connect$ to ! prim>y circuit4 ,:at happ5s w n hurt ! dog1 b he w travel = home z fa/ z f\r legs c c>ry him4 ,exp]im5t #i--;,h[ to ,make an ,electric ,sp>k ,photograph ,itself4 ,?is exp]im5t mu/ be conduct$ 9 a d>k room ) ! aid ( a photograph]'s ruby lamp s t ! photographic plates us$ w n become light /ruck & spoil$4 ,place an ord9>y photographic plate on a piece ( %eet metal ) ! coat$ or s5sitive side up4 ,connect ! piece ( %eet metal to "o ( ! second>y t]m9als ( ! sp>k coil by means ( a wire4 ,!n sift "s dry />* p[d]1 fl\r ( sulphur or talcum p[d] ?r\gh a ?9 piece ( gauze on to ! plate4 ,lead a %>p po9t$ wire f ! o!r second>y t]m9al ( ! coil4 ,complete ! prim>y circuit ( ! coil j long en\gh to make "o s+le sp>k4 ,wipe ! p[d] (f ! plate ?or\ghly & develop x 9 ! usual mann]4 ,! negative w %[ a peculi> electric dis*>ge look+ v mu* l sea moss4 ,no two photographs w be alike4 ,! te/ results are obta9$ :5 only "o or two sp>ks are all[$ to pass4 ,arts & ,sci5ce ,s]ies ,no4 #i ,home-made ,electrical ,app>atus ,a ,practical ,h&book = ,amateur ,exp]im5t]s ,9 ,?ree ,p>ts 99,volume ,,iii99 ,second ,edition 99,,by99 99,a4 ,m4 ,p[ell99 ,,publi%$ ,,by ,,cole ,,morgan1 ,inc4 ,publi%]s ( ! ,arts & ,sci5ce ,s]ies ,p4,o4 ,,box #dgc ,,city ,,hall ,,/ation ,,new ,,york1 ,n4 ,y4 ,pr9t$ 9 ,u4 ,s4 ,a4 ,copyright #aiah by ,,cole ,,morgan1 ,inc4 ,,*apt] ,,xii4 ,,h[ ,,to ,,make ,a ,,dynamo-,,motor ,x is v difficult to con/ruct a fir/ class dynamo )\t resort to ! mat]ials & me?ods employ$ 9 ! manufacture ( comm]cial ma*9es4 ,! necessity = c>eful workman%ip 9 e detail1 c h>dly be ov]e/imat$4 ,poor workman%ip & poor mat]ials w always result 9 an ineffici5t ma*9e4 ,telegraph in/rum5ts1 toy motors1 etc41 may be con/ruct$ f all sorts ( odds & ends ( mat]ials1 & !y w "w fairly well1 b 9 ord] to make a real dynamo x w be necess>y to use c]ta9 mat]ials = :i* no?+ c be sub/itut$4 ,illu/ration3 ,,fig4 #abc--;,front view ( ! ,field ,ca/+4 ,! field ca/+ mu/ be s(t gray ca/ iron & ! magnet wire %\ld be ( good quality4 ,bo? ! field & ! armature ( ! small dynamo describ$ 9 ! foll[+ pages are ca/ iron & patt]ns w be necess>y 9 ord] to =m ! m\lds = ! ca/+s4 ,x may be possible = sev]al exp]im5t]s to club toge!r & make ! patt]ns1 or h !m made1 = build+ ?is dynamo4 ,! dynamo describ$ has an output ( ab\t t5 watts4 ,x may also be us$ z a motor & z su* w develop consid]able p[]4 ,! ca/+s = ?is ma*9e are already on ! m>ket & may be obta9$ f ! publi%]s ( ?is book4 ,illu/ration3 ,,fig4 #abd4--,side elevation ( ! ,field ,ca/+4 99,! ,field99 is %[n 9 ,figures #abc & #abd4 ,! details 9 bo? illu/rations are fully dim5sion$ & probably no comm5t 9 t direction w be necess>y4 ,if ! exp]im5t] decides to make 8 own patt]ns he %\ld use e c>e to make c]ta9 t !y are c>efully & accurately made4 ,!y %\ld be made ( wood & f9i%$ by rubb+ ) f9e s&pap] until p]fectly smoo? & !n giv5 a coat ( %ellac4 ,! p>ts %\ld also be giv5 a slight draft or tap] t[>d "o side s t ! patt]n may be easily )drawn f ! m\ld4 ,illu/ration3 ,,fig4 #abe4--;,details ( ! ,armature4 ,! easie/ way to bore out ! tunnel ( ! field is to p]=m ! "w on a la!4 ,if no la! is h&y1 ! "w c be accompli%$ ) no?+ m ?an ! aid ( a file & a little pati5ce4 ,x %\ld be clean$ out until x is p]fectly r\nd & measures "o & five-sixte5?s ( an in* 9 diamet]4 ,any r\gh spots on ! ca/+ %\ld be smoo!d up ) a file4 99,! ,armature99 is illu/rat$ 9 ,figure #abe4 ,! c5tre ( ! armature %\ld be bor$ out to fit a ?ree-sixte5?s in* %aft4 ,! %aft is a piece ( /eel rod f\r in*es long4 ,! outside ( ! armature %\ld be turn$ d[n to a diamet] ( "o & "o-qu>t] in*es1 mak+ x "o-sixte5? ( an in* small] 9 diamet] ?an ! tunnel 9 ! field4 99,! ,commutator99 is illu/rat$ 9 ,figure #abf4 ,x has two sections & consi/s ( a %ort piece ( brass tub+ fitt$ on a fibre core & split l5g?wise on two opposite sides s t ea* section is insulat$ f ! o!r4 ,x is n v difficult to make su* a commutator4 ,a hole is drill$ ?r\gh ! fibre1 :i* fits v tightly on ! %aft4 ,! %aft is !n plac$ 9 a la! ) ! fibre 9 position & ! latt] turn$ d[n until a piece ( sev5-sixte5?s in* brass tub+ c be driv5 on4 ,! tube %\ld be five-eigh?s ( an in* long4 ,!n m>k two l9es along ! tube at po9ts diametrically opposite4 ,bore two small holes to receive two small screws1 a %ort di/ance away f ea* side ( ^! l9es & on ea* side ( !m4 ,make c]ta9 t ! screws d n g into ! fibre f> en\gh to t\* ! %aft4 ,! commutator may !n be split along ea* side ( ! l9es ) a hacksaw1 cont9u+ ! cut "r ?r\gh ! brass & slightly into ! insulat+ core4 ,! heads ( ! screws %\ld be fil$ (f flu% ) ! surface ( ! commutator & ! latt] tru$ up & made p]fectly smoo?4 ,illu/ration3 ,,fig4 #abf4--,! ,commutator4 ,if ea* section ( ! commutator is provid$ ) a small brass ma*9e screw ne> ! back edge z %[n 9 ,figure #abf1 x w greatly facilitate connection ) ! ends ( ! armature w9d+s4 ,! armature1 %aft & commutator1 z !y %\ld appe> :5 assembl$ are %[n 9 ,figure #abg4 ,^? portions ( ! armature & %aft :i* w come into contact ) ! armature wire %\ld be insulat$ ) %ellac$ pap]4 ,soak ! pap] 9 ! %ellac until x is s(t & x c be v easily press$ into prop] %ape to fit ! armature4 ,all[ ! %ellac to dry & h>d5 be=e w9d+ on ! wire4 ,illu/ration3 ,,fig4 #abg4--,! ,armature & ,commutator ,assembl$ on ! ,%aft ready = w9d+4 ,! armature w n ne$ to be fa/5$ on ! %aft if x is a tight fit & _c be twi/$4 ,if x is loose1 x may be fa/5$ by means ( a small set screw or p94 ,! commutator %\ld fit ! %aft v tightly s t x w n slip or twi/4 99,! ,armature ,w9d+99 is ,no4 #bj ,b4 ,s4 ,gauge s+le-cotton cov]$ magnet wire4 ,suffici5t wire %\ld be put on to fill up ! w9d+ space completely4 ,d n1 h[ev]1 put on too mu* wire or x w int]f]e ) ! field magnets & prev5t ! armature f revolv+4 ,te/ ! w9d+ aft] x is f9i%$ to see t ! wire is n gr\nd$ or connect$ to ! armature at any po9t4 ,if ! insulation is p]fect1 give ! w9d+ a good coat ( %ellac & all[ x to dry4 ,! ends ( ! w9d+ are ea* connect$ to "o ( ! commutator sections z %[n 9 ,figure #abg4 99,! ,field ,w9d+99 is ,no4 #bj ,b4 ,s4 ,gauge s+le cotton cov]$ wire4 ,! wire %\ld be w\nd on 9 smoo?1 ev5 lay]s1 & ! w9d+ space betwe5 ! flanges completely fill$ up4 ,! w9d+ space 9 ! field frame %\ld be insulat$ ) %ellac$ pap] by cov]+ ! core & ! flanges4 ,! flanges are be/ insulat$ ) pap] disks cut 9 two halves s t !y w slip ar\nd ! core4 ,illu/ration3 ,,fig4 #abh4--;,details ( ! ,wood5 ,base4 ,! details ( ! wood5 base are %[n 9 ,figure #abh4 ,x is a rectangul> %ap$ piece ( wood1 five in*es long1 f\r in*es wide & five-eigh?s ( an in* ?ick4 ,! corn]s are slightly r\nd$4 99,! ,be>+s99 are small brass ca/+s4 ,!y are bo? alike4 ,! details are illu/rat$ 9 ,figure #abi4 ,x w be necess>y to make a wood5 patt]n & s5d x to a brass f\ndry = ca/+s4 ,! ca/+s %\ld be smoo!d up ) a file & !n drill$4 ,! %aft hole %\ld be ?ree-sixte5?s ( an in* 9 diamet] & ! screw holes j l>ge en\gh to pass an #h-cb screw4 ,! be>+s are fa/5$ to ! project+ arms on ! field ca/+ by means ( r\nd head$ #h-cb brass ma*9e screws4 ,! armature %\ld revolve exactly 9 ! c5tre ( ! tunnel 9 ! field & %\ld be free 9 ! be>+s s t x runs easily & )\t b9d+4 99,! ,bru%es99 are illu/rat$ 9 ,figure #aca4 ,!y are cut out ( spr+ copp] & b5t accord+ to ! %ape & dim5sions %[n4 ,! field is fa/5$ to ! base by means ( two l>ge ma*9e screws pass+ upw>ds ?r\gh ! base into ?read$ holes 9 ! bottom ( ! ca/+4 ,! bru%es are b5t at "r angles & m\nt$ on ! base on ei!r side ( ! commutator ) small r\nd head$ wood screws4 ,!y %\ld be> firmly aga9/ ! commutator4 ,! commutator %\ld be 9 su* a position on ! %aft1 9 relation to ! armature1 t ! divid+ l9es betwe5 ! two sections are directly opposite ! c5tre ( ! iron faces ( ! armature z %[n 9 ,figure #abg4 ,illu/ration3 ,,fig4 #abi4--;,details ( ! ,be>+s4 ,illu/ration3 ,,fig4 #acj4--,! ,pulley4 ,illu/ration3 ,,fig4 #aca4--,! ,bru%es4 ,! %aft %\ld be fitt$ ) a small groov$ pulley to accommodate a small r\nd belt4 ,! complet$ dynamo is %[n 9 ,figure #acb4 ,! dynamo is connect$ 9 :at is kn[n z %unt4 ,"o t]m9al ( ! field magnet is connect$ to "o bru% & ! o!r t]m9al to ! o!r bru%4 ,a wire is !n l$ f ea* "o ( ! bru%es to a b9d+ po/4 ,be=e ! dynamo w g5]ate curr5t x w be necess>y to magnetize ! field by connect+ ! t]m9als to sev]al /rong batt]ies & all[+ ! curr5t to fl[ ?r\gh = sev]al seconds4 ,a %unt w\nd dynamo w only g5]ate :5 run 9 a c]ta9 direction4 ,9 ord] to make x g5]ate :5 run 9 ! opposite direction1 x is necess>y to rev]se ! field connections to ! bru%es4 ,illu/ration3 ,,fig4 #acb4--,! ,complet$ ,dynamo4 ,! dynamo w be f\nd to op]ate z a v p[]ful little motor1 b on acc\nt ( hav+ only a two pole armature1 x mu/ be />t$ :5 ! curr5t is turn$ on by giv+ ! %aft a twi/4 ,! dynamo may be driv5 by a small wat] motor or f ! driv+ :eel ( a sew+ ma*9e4 ,x may be us$ z a g5]ator = light+ lamps1 r++ bells1 electroplat+1 etc4 ,,*apt] ,,xiii4 ,,an ,,electric ,,batt]y ,,motor4 ,,an electric motor has two ess5tial p>ts4 ,^! are a field magnet = furni%+ a /rong magnetic field & a revolv+ armature4 ,x is an easy matt] to make a /rong electric motor suitable to op]ate on batt]ies by ! ex]cise ( a little c>eful workman%ip4 ,! field frame & armature ( ! motor %[n 9 ,figure #acc are lam9at$1 t is1 built up ( sep>ate %eets ( iron4 ,!y may be made out ( %eet t9 or ord9>y /ove pipe iron4 ,! *eape/ & simple/ me?od ( secur+ good flat mat]ial is to get "s old scrap f a t9n]'s or plumb+ %op4 99,! ,details ( ! ,field99 are %[n 9 ,figure #acd4 ,! exact %ape & dim5sions c be und]/ood by ref]5ce to ! illu/ration4 ,lay out "o lam9ation v c>efully z a patt]n4 ,cut x out & smoo? up ! edges1 mak+ c]ta9 t x is p]fectly true to size & %ape4 ,!n use x z a template to lay out ! o!r lam9ations by plac+ x on ! metal & scrib+ a l9e ar\nd ! edges ) a %>p po9t$ ne$le4 ,en\gh lam9ations %\ld be cut out to make a pile five-eigh?s ( an in* high :5 tightly press$ toge!r4 ,illu/ration3 ,,fig4 #acc4--,! complet$ ,electric ,motor4 99,! ,armature99 is made 9 exactly ! same mann] z ! field frame1 t is1 by cutt+ out a patt]n accord+ to ! %ape & dim5sions %[n 9 ,figure #acf & us+ x z a template to lay out ! o!r lam9ations4 ,en\gh %\ld be cut to make a pile five-eigh?s ( an in* high :5 tightly squeez$ toge!r4 ,illu/ration3 ,,fig4 #acd4--;,details ( ! ,field ,frame4 ,illu/ration3 ,,fig4 #ace4--,! ,assembl$ ,field ready = ,w9d+4 ,! armature is "o & ?ree-sixte5?s in*es 9 diamet]4 ,! hole 9 ! field frame :i* accommodates ! armature is "o in* & "o-qu>t] 9 diamet] s t !re is a space 9 betwe5 = ! armature to revolve 94 ,! hole ?r\gh ! c5t] = ! %aft %\ld be ( su* diamet] t ! lam9ations w =ce v tightly on a %aft "o-eigh? ( an in* 9 diamet]4 ,! lam9ations %\ld be v c>efully flatt5$ & !n =c$ ov] ! /eel %aft :i* is two & "o-eigh? in*es long4 ,clean up all ! r\gh edges ) a file & smoo? ! outside s t x w revolve prop]ly 9 ! field )\t scrap+4 ,illu/ration3 ,,fig4 #acf4--;,details ( ! ,armature ,lam9ation4 ,illu/ration3 ,,fig4 #acg4--,! ,armature assembl$ on ! ,%aft ready to ,w9d4 ,figure #acg illu/rates ! armature assembl$ on ! %aft & ready to be w\nd4 99,! ,armature ,w9d+s99 consi/ ( f\r lay]s ( ,no4 #bb ,b4 ,s4 ,gauge d\ble cotton cov]$ magnet wire w\nd ar\nd ea* leg4 ,! iron %\ld be v c>efully insulat$ ) %ellac$ pap] be=e ! wire is put 9 position s t !re w n be any dang] ( %ort circuit due to ! %>p edges ( ! metal cutt+ ?r\gh ! insulation4 ,ea* leg %\ld conta9 ! same numb] ( turns ( wire & all %\ld be w\nd 9 ! same direction4 ,! ,commutator is illu/rat$ 9 ,figure #ach4 ,x consi/s ( a piece ( brass tub+ sev5-sixte5?s ( an in* long1 five-sixte5?s inside & ?ree-eigh?s ( an in* outside4 ,x %\ld be =c$ onto a piece ( fibre five-sixte5?s ( an in* 9 diamet] & sev5-sixte5?s ( an in* long4 ,split ! tube into ?ree equal p>ts by divid+ x longitud9ally ) a hack-saw4 ,make a fibre r+ :i* w =ce onto ! tube v tightly :5 x is 9 position on ! fibre core & s hold ! ?ree commutator sections firmly 9 position4 ,! sections %\ld be s arrang$ t !re is a small space betwe5 ea* two & !y are p]fectly insulat$ f ea* o!r4 ,! fibre core %\ld h a "o-eigh? in* hole ?r\gh ! c5tre s t x may be =c$ tightly onto ! %aft & up aga9/ ! armature aft] ! w9d+s are 9 position4 ,! commutator %\ld be 9 su* a position t ! split betwe5 ea* two sections come directly opposite ! c5tre ( ea* w9d+4 ,suppose t ! w9d+s are lett]$ ,a1 ,b1 & ,c1 ! commutator section betwe5 ,a & ,b is numb]$ #a1 t betwe5 ,a & ,c is ,no4 #b1 & ! "o betwe5 ,c & ,b is ,no4 #c4 ,!n ! inside t]m9al ( ,b is connect$ to ! outside t]m9al ( ,a & sold]$ to ! end ( commutator section ,no4 #a close to ! w9d+4 ,! inside end ( ,b is connect$ to ! outside t]m9al ( ,c & to commutator section ,no4 #b4 ,! inside end ( w9d+ ,c is connect$ to ! outside ( ,b & to commutator section ,no4 #c4 ,! connection ( ! armature w9d+s to ! commutator are repres5t$ by ! diagram 9 ,figure #aci4 ,illu/ration3 ,,fig4 #ach4--,! ,commutator4 ,illu/ration3 ,,fig4 #aci4--;,diagram %[+ h[ ! ,armature ,coils are connect$ to ! ,commutator ,sections4 ,illu/ration3 ,,fig4 #adj4--,! ,be>+s4 99,! ,field ,w9d+99 consi/s ( five lay]s ( ,no4 #ah ,b4 ,s4 d\ble cotton cov]$ wire4 ,a mu* neat] job may be made ( ?is "p ( ! "w if two fibre heads are cut to slip ov] ! field & support ! ends ( ! w9d+ z %[n 9 ! illu/ration 9 ,figure #acc4 99,! ,be>+s99 are illu/rat$ 9 ,figure #adj4 ,!y are made out ( ?ree-eigh?s in* brass /rip "o-sixte5? ( an in* ?ick by b5d+ & drill+ z %[n 9 ! illu/ration4 ,! location ( ! holes is be/ und]/ood f ! draw+4 ,! l>g] be>+ is assembl$ on ! field at ! side t[>ds ! commutator4 ,assembl+ ! motor is a comp>atively easy matt] if x is done prop]ly & c>efully4 ,! be>+s are m\nt$ on ! field frame by screws pass+ ?r\gh ! holes ,b & ,b into a nut on ! outside ( ! be>+ at ! opposite side ( ! field4 ,! armature %\ld revolve freely )\t b9d+ & )\t any dang] ( scrap+ aga9/ ! field4 ,slip "s small fibre wa%]s ov] ! ends ( ! %aft betwe5 ! armature & ! be>+s s z to take up all end play4 99,! ,bru%es99 are made ( spr+ copp] accord+ to ! %ape & dim5sions %[n 9 ,figure #ada4 ,!y c be cut out ) a pair ( snips4 ,ea* bru% is m\nt$ on a small fibre block support$ on ! l>ge motor be>+4 ,! holes m>k$ ,a & ,c 9 ! illu/ration %\ld be ?read$ ) a #d-cf tap4 ,! hole ,b %\ld be made "o-eigh? ( an in* 9 diamet] & drill$ all ! way ?r\gh ! block4 ,! holes ,a & ,c are us$ to fa/5 ! blocks to ! be>+4 ,! bru%es are fa/5$ to ! blocks by means ( a #f-cb screw ) a nut on ! l[] end4 99,! ,base99 is a rectangul> block1 ?ree in*es wide1 ?ree & "o-half in*es long & ?ree-eigh?s ( an in* ?ick4 ,! motor is fa/5$ to ! base by f\r small "r angl$ brackets b5t out ( /rip brass & secur$ to ! field frame by two ma*9e screws pass+ ?r\gh ! holes ,h & ,h into a nut at ! opposite end4 ,illu/ration3 ,,fig4 #ada4--,! ,bru%es4 ,"o t]m9al ( ! field w9d+ is connect$ to a b9d+ po/ m\nt$ on ! base4 ,! o!r t]m9al ( ! field is connect$ to ! "r h& bru%4 ,! end ( ! wire %\ld be plac$ "u ! head ( ! screw :i* holds ! bru% to ! fibre block4 ,! bru% %\ld be on ! "u side ( ! block s t x be>s aga9/ ! "u side ( ! commutator4 ,! left h& bru% be>s aga9/ ! upp] side ( ! commutator & is connect$ to a second b9d+ po/ on ! base ( ! motor4 ,?is makes x a s]ies motor1 t is1 ! armature & ! field are connect$ 9 s]ies4 ,illu/ration3 ,,fig4 #adb4--,! ,fibre ,block = support+ ea* ,bru%4 ,! motor is n[ ready to run4 ,put a drop ( oil on ea* be>+ & make c]ta9 t ! curv$ portion ( ! bru%es be> firmly aga9/ ! c5tre ( ! commutator on opposite sides4 ,! armature hav+ ?ree poles1 %\ld />t )\t assi/ance & run at high spe$ z soon z ! curr5t is appli$4 ,two cells ( dry or o!r batt]y %\ld be suffici5t4 ,! motor may be fitt$ ) a small pulley s t its p[] may be utiliz$ = driv+ small models4 ,,*apt] ,,xiv4 ,,h[ ,,to ,,build ,,an ,,electric ,,eng9e4 ,an ,electric eng9e is really a =m ( electric motor b diff]s f ! mo/ common =m ( ! latt] 9 t ! armature1 in/ead ( revolv+1 oscillates back & =?1 l ! pi/on ( a /eam or gasol9e eng9e4 ,electric eng9es are n z effici5t z electric motors f ! /&po9t ( ! am\nt ( p[] deliv]$ 9 proportion to ! curr5t us$1 b !y make v int]e/+ models & ! "y exp]im5t] w d]ive fully z mu* pleasure 9 con/ruct+ "o z f ! con/ruction ( an electric motor4 ,v>i\s =ms ( electric eng9es 7 made be=e ! fir/ practical electric motor 0 inv5t$4 ,!y am\nt$ to little m ?an curiosities1 h[ev]1 & c\ld only be us$ :]e ! exp5se ( electric curr5t 0 n to be reg>d$4 ,illu/ration3 ,,fig4 #adc4--;,complet$ ,electric ,eng9e4 ,! eng9e illu/rat$ 9 ,figure #adc is ( ! d\ble action type4 ,x is provid$ ) two electromagnets arrang$ s t "o pulls ! armature =w>d & ! o!r pulls x back4 ,! motion ( ! armature is transmitt$ to ! %aft by means ( a connect+ rod & crank4 ,x is v simple to build & ! design is su* t x w op]ate equally well :e!r x is made l>ge or small4 ,if y d n happ5 to h all ! necess>y mat]ials to build an eng9e accord+ to ! dim5sions %[n 9 ! draw+s y c make x j "o-half t size & x w "w equally well al?\gh x w ( c\rse n give z mu* p[]4 ,! complete eng9e is %[n 9 ,figure #adc4 ,all ! v>i\s p>ts h be5 m>k$ s t y c easily id5tify !m 9 ! o!r draw+s4 ,x is well to /udy ?is illu/ration c>efully fir/ s t y w und]/& j h[ all ! p>ts are arrang$4 99,! ,base99 is illu/rat$ 9 ,figure #add4 ,x is made ( a piece ( h>dwood1 sev5 in*es long1 ?ree & "o-half in*es wide & "o-half an in* ?ick4 ,illu/ration3 ,,fig4 #add4--,! ,eng9e ,base4 99,! ,magnets994 ,! size ( ! electromagnets w l>gely det]m9e ! dim5sions ( ! re/ ( ! eng9e4 ,! magnets %[n 9 ,figure #ade are made ( ?ree-eigh?s in* r\nd iron1 two & "o-half in*es long1 provid$ ) two fibre wa%]s "o & "o-eigh? in*es 9 diamet]4 ,"o end ( ea* ( ! /eel cores is drill$ & tapp$ to receive an #h-cb iron screw4 ,! exp]im5t] may possibly be able to secure "s old magnet cores fitt$ ) fibre heads f an old telephone bell or r+] z !y are sometimes call$4 ,a suitable bolt c be made to s]ve ! purpose by cutt+ x (f to ! "r dim5sions ) a hack saw4 ,if a drill & a tap are n available = drill+ & tapp+ ! end s t ! core c be prop]ly m\nt$ 9 ! frame ( ! eng9e x is possible by ! ex]cise ( a little +5uity to use ! ?read$ portion ( a bolt to good advantage4 ,! hole 9 ! frame %\ld !n be made l>g] s t ! end ( ! bolt w slip ?r\gh in/ead ( an #h-cb screw & ! core clamp$ 9 position by a nut on ea* side4 ,! fibre wa%]s are spac$ two & "o-sixte5? in*es ap>t4 ,! space 9 betwe5 %\ld be w\nd full ( ,no4 #ah ,b4 ,s4 ,gauge cotton cov]$ magnet wire4 ,be=e w9d+ 9 ! wire1 cov] ! core ) a lay] ( pap] s t ! wire does n t\* ! metal4 ,! ends ( ! wire %\ld be l$ out ?r\gh small holes 9 ! fibre heads4 ,illu/ration3 ,,fig4 #ade4--;,details ( ! ,electromagnet ,bobb94 ,x is n absolutely necess>y to use ,no4 #ah ,b4 ,s4 ,gauge wire 9 w9d+ ! magnets b ?is is ! size :i* w give ! be/ results on ! av]age batt]y4 ,illu/ration3 ,,fig4 #adf4--;,details ( ! ,eng9e ,frame4 ,if y use l>g] wire1 ! eng9e w require m curr5t f ! batt]y4 ,if y use f9] wire1 a batt]y ( a high] voltage w be necess>y4 ,! curr5t consumption w1 h[ev]1 be less4 99,! ,frame499--,! electromagnets are m\nt$ 9 ! frame ( ! eng9e by means ( two screws pass+ ?r\gh ! holes ,e & ,d4 ,! details ( ! frame are illu/rat$ 9 ,figure #adf4 ,x is made ( a /rip ( wr\ght iron or cold roll$ /eel1 n9e & "o-qu>t] in*es long1 an in* or an in* & "o-eigh? wide & "o-eigh? ( an in* ?ick4 ,! mat]ial = mak+ ?is "p ( ! eng9e & also ! be>+s c probably be/ be obta9$ at "s blacksmi? %op or h>dw>e /ore4 ,heavy galvaniz$ iron c be us$ b x is n usually ?ick en\gh & x may be necess>y use two ?icknesses4 ,! ends ( ! /rip are r\nd$ & b5t at "r angles s z to =m a ,u-%ap$ piece ) sides "o & ?ree-qu>t]s in*es high4 ,! holes ,d & ,e %\ld be l>ge en\gh to pass an #h-cb screw4 ,! holes ,a1 ,b & ,c %\ld be ab\t "o-eigh? ( an in* 9 diamet]4 ,!y are us$ to pass ! screw :i* hold ! frame ( ! eng9e to ! wood5 base4 ,illu/ration3 ,,fig4 #adg--,! ,be>+s4 99,! ,be>+s99 are %[n 9 ,figure #adg4 ,!y are ,u-%ap$ & are made out ( a /rip ( iron or /eel 9 ! same mann] z ! frame ( ! eng9e b are ?ree-qu>t]s ( an in* wide in/ead ( an in* & "o-eigh?4 ,! dim5sions w be und]/ood be/ by ref]r+ to ! draw+4 ,! #c_/cb in* holes ne> ! top ( ea* side are ! be>+ holes = ea* end ( ! %aft4 ,! "o-eigh? in* holes bel[ are us$ to fa/5 ! bru% hold] 9 position4 ,! holes 9 ! bottom s]ve to fa/5 ! be>+s to ! base4 ,illu/ration3 ,,fig4 #adh4--;,details ( ! ,%aft4 99,! ,%aft99 w probably prove ! mo/ difficult "p ( ! eng9e to make prop]ly4 ,! details are giv5 9 ,figure #adh4 ,x is made ( a piece ( "o-eigh? in* /eel rod b5t s t x has a ?r[ ( "o-half an in*1 t is1 is (fset "o-qu>t] ( an in* s t ! connect+ rod moves back & =? a di/ance ( "o half an in*4 ,! f9i%$ %aft %\ld be ?ree in*es long4 ,! piece ( /eel us$ %\ld be long] ?an ?is1 s t x c be cut (f to exact dim5sions aft] ! %aft is f9i%$4 ,a second crank %\ld be b5t 9 "o end ( ! %aft s z to =m an (fset contact = ! bru%es4 ,?is second crank w h to be at "r angles to ! fir/ "o & %\ld be mu* small]4 ,! ends ( ! %aft are turn$ or fil$ d[n to a diamet] ( ?ree-?irty second ( an in* = a di/ance ( ab\t ! same am\nt s t !y w fit 9 ! be>+ holes & turn freely b n all[ ! :ole %aft to slip ?r\gh4 ,! "w ( mak+ ! %aft w require a small vice1 a light hamm]1 files & a c\ple ( pairs ( pli]s4 ,"o pair ( pli]s %\ld be ( ! r\nd nos$ type & ! o!r a pair ( ord9>y squ>e jaw$ side cutt]s4 ,x may require two or ?ree attempts be=e a p]fect %aft is secur$4 ,:5 f9i%$ x %\ld be p]fectly true & turn freely 9 ! holes4 ,! be>+s c be adju/$ slightly by b5d+ s t ! %aft w fit 9 ! holes & be free b yet n be loose en\gh to slip out4 99,! ,armature99 is a /rip ( s(t iron1 two & "o-eigh? in*es long1 sev5-sixte5?s ( an in* wide & ?ree-sixte5?s ( an in* ?ick4 ,a "o-sixte5? in* slot1 ?ree-eigh?s ( an in* long is cut 9 "o end4 ,a "o-sixte5? in* hole is drill$ ?r\gh f "o side to ! o!r1 "o-eigh? ( an in* f ea* end4 ,! hole :i* passes ?r\gh ! slot is us$ to pass ! p9 :i* pivots ! armature to ! connect+ rod4 ,! o!r hole is us$ to m\nt ! armature 9 its be>+4 ,! armature be>+ is a small edition ( ! "o :i* is us$ to support ! eng9e %aft4 ,! details & ! dim5sions are giv5 9 ! l[] left h& side ( ,figure #adi4 ,! armature is %[n 9 ! c5tre ( ! same illu/ration4 ,! connect+ rod is illu/rat$ at ! "r4 ,?is is made f a /rip ( ?ree-sixty-f\r?s in* brass1 ?ree-sixte5?s ( an in* wide & "o & five-eigh?s in*es long4 ,a "o-eigh? in* hole %\ld be drill$ close to "o end & a "o-sixte5? in* hole close to ! o!r4 ,illu/ration3 ,,fig4 #adi4--,! ,armature1 ,armature ,be>+ & ,connect+ ,rod4 99,! ,bru%es99 are two /rips ( ?9 phosphor bronze %eet1 two & ?ree-sixte5?s in*es long & n9e-?irty-seconds ( an in* wide4 ,!y are illu/rat$ 9 ,figure #aej4 ,! block ^u :i* !y are m\nt$ is h>d fibre4 ,x is "o & five-eigh?s in*es long & ?ree-eigh?s ( an in* squ>e4 ,illu/ration3 ,,fig4 #aej4--,! ,bru%es4 99,! ,fly:eel994 ,x may be possible to secure a fly:eel = ! eng9e f "s old toy4 ,x %\ld be ab\t ?ree & "o-half in*es 9 diamet]4 ,a fly:eel c be made out ( %eet iron or /eel by foll[+ ! sugge/ion 9 ,figure #aea1 :i* %[s a :eel cut out ( "o-eigh? in* %eet /eel4 ,x is giv5 ! appe>ance ( hav+ spokes by bor+ six ?ree-qu>t] in* holes ?r\gh ! face z %[n4 ,! hole 9 ! c5tre ( ! :eel %\ld be "o-eigh? ( an in* 9 diamet]4 ,! :eel is slipp$ ov] ! %aft & fa/5$ 9 position by sold]+4 ,! p>ts are n[ all ready to assemble into ! complete eng9e4 ,m\nt ! electromagnets 9 ! frame & fa/5 ! frame d[n to ! wood5 base s t "o end ( ! frame comes practically flu% ) ! left h& edge ( ! base4 ,fa/5 ! be>+ across ! frame at "r angles by a screw pass+ ?r\gh ! c5tre hole 9 ! bottom ( ! be>+1 ?r\gh ! hole ,a & into ! base4 ,! bottom ( ! be>+ %\ld be b5t slightly s z to /raddle ! frame4 ,! be>+s %\ld be secur$ & prev5t$ f turn+ or twi/+ by two screws pass$ ?r\gh ! o!r two holes 9 ! bottom4 ,use r\nd-head$ wood screws 9 m\nt+ ! be>+ & ! frame4 ,! armature be>+ %\ld be m\nt$ on ! frame directly betwe5 ! two electromagnets4 ,!n place ! armature 9 position by slipp+ a piece ( "o-sixte5? in* brass rod ?r\gh ! be>+ holes & ! hole 9 ! l[] "p ( ! armature4 ,illu/ration3 ,,fig4 #aea4--;,a ,fly:eel may be cut f %eet iron4 ,sold] ! fly:eel 9 position on ! %aft & snap ! latt] into ! be>+s4 ,adju/ ! be>+s s t ! %aft w turn freely4 ,! connect+ rod %\ld be slipp$ ov] ! %aft be=e x is plac$ 9 ! be>+s4 ,fa/5 ! o!r end ( ! connect+ rod to ! armature by means ( a piece ( "o-sixte5? in* brass rod :i* passes ?r\gh ! small holes bor$ = t purpose4 ,:5 ! fly:eel is spun ) ! f+]s1 ! armature %\ld move back & =? betwe5 ! two electromagnets & almo/ b n q t\* ! two magnet poles4 ,all ! mov+ p>ts %\ld be fitt$ firmly toge!r b be free en\gh s t !re is no unnecess>y friction & s t ! eng9e w cont9ue to run = a few seconds :5 ! fly:eel is spun ) ! f+]s4 ,! bru%es1 support$ on _! fibre block %\ld be m\nt$ on ! be>+ by means ( two screws pass+ ?r\gh ! holes 9 ! be>+ into ! block4 ,! position ( ! bru%es %\ld be su* t ! %aft passes betwe5 ! two upp] ends b does n t\* !m unless ! small contact crank m5tion$ above is 9 prop] position to d s4 ,! prop] adju/m5t ( ! bru%es1 s t !y make contact ) ! %aft at ! prop] mom5t1 w l>gely det]m9e ! spe$ & p[] :i* ! f9i%$ eng9e w develop4 ,two b9d+ po/s %\ld be m\nt$ on ! "r h& end ( ! base s t ! eng9e c be easily connect$ to a batt]y4 ,connect "o t]m9al ( ! "r h& electromagnet to "o ( ! b9d+ po/s4 ,run ! o!r t]m9al ( ! electromagnet to ! bru% on ! opposite side ( ! %aft4 ,connect "o t]m9al ( ! left h& electromagnet to ! o!r b9d+ po/ & run ! o!r t]m9al to ! bru% on ! opposite side ( ! %aft4 ,save = a few m9or adju/m5ts1 ! eng9e is n[ ready to run4 ,connect two or ?ree cells ( dry batt]y to ! two b9d+ po/s & turn ! fly:eel s t x moves f "r to left across ! top4 ,j z ! crank passes dead c5tre & ! armature />ts to move back away f ! left h& magnet1 ! small contact crank %\ld t\* ! left h& bru% & s5d ! curr5t ?r\gh ! "r h& magnet4 ,?is w draw ! armature ov] to ! "r4 ,j be=e ! armature gets all ! way ov] to ! "r1 ! contact %\ld break connection ) ! left h& bru% & int]rupt ! curr5t s t ! in]tia ( ! fly:eel w cause x to keep mov+ & ! armature to />t to move ov] t[>ds ! left h& magnet at :i* po9t ! contact on ! %aft %\ld comm5ce to be> aga9/ ! "r h& bru%1 ?us ?r[+ ! left h& magnet into circuit & draw+ ! armature ov] to t side4 ,if ! bru%es & ! cranks are 9 prop] relation to ea* o!r ! eng9e w cont9ue to repeat ?is op]ation & gradually ga9 spe$ until x is runn+ at a good rate4 ,! appe>ance ( ! eng9e c be improv$ by pa9t+ ! metal p>ts black & ! fly:eel r$4 ,! magnets c be wrapp$ ) a piece ( bright r$ clo? to protect ! wire aga9/ injury & bright5 ! appe>ance ( ! eng9e4 ,,*apt] ,,xv4 ,,m9iature ,,batt]y ,,light+4 ,! tung/5 lamp has op5$ wond]ful possibilities 9 ! field ( electric light+ by means ( m9iature lamps op]at$ f batt]ies4 ,! tung/5 lamp uses less ?an "o ?ird ! am\nt ( curr5t requir$ by ! old-fa%ion$ c>bon filam5t lamps 9 produc+ ! same c&le p[]4 ,?is means t ! batt]y w la/ ?ree times z long4 ,m9iature light+ is "o ( ! mo/ practical phases ( exp]im5tal electricity to :i* ! exp]im5t] c apply 8 "t4 ,batt]y op]at$ lamps w be f\nd invaluable 9 _m places = light+ d>k corn]s1 hallways1 b>ns1 g>ages1 camps1 bungal[s1 work%ops1 etc4 99,tung/5 ,batt]y ,lamps99 are made 9 a great _m diff]5t /yles & sizes4 ,! smalle/ sizes are us$ = fla%lights1 h&-lant]ns1 etc4 ,^! are n rat$ accord+ to _! c&lep[]1 b to ! voltage :i* !y %\ld be op]at$ on4 ,fla%light lamps w be f\nd satisfactory z a means ( illum9at+ closets1 cell>s1 /airways1 etc41 b d n give suffici5t light = read+ or any purpose ( t sort4 ,! light :i* !y give v>ies f "o to ?ree c&le-p[] accord+ to ! size ( ! lamp4 ,!y are made = #a4e1 #b4h1 #c4h & #e4h volts or respectively "o1 two1 ?ree & f\r dry cells4 ,fla%light lamps are provid$ ) :at is kn[n z a m9iature base only4 ,a v simple light+ arrangem5t :i* w prove exce$+ly useful = illum9at+ a d>k closet1 a coal b9 or ! face ( a clock1 etc41 consi/s ( a #a4e volt lamp1 a s+le cell ( dry batt]y & a suitable swit* & wire4 ,su* an in/allation may be made at a co/ ( less ?an sev5ty-five c5ts4 ,illu/ration3 ,,fig4 #aeb4--,small ,tung/5 ,batt]y ,lamps4 ,! lamp is m\nt$ 9 :at is kn[n z a m9iature porcela9 base receptacle4 ,! swit* may mo/ conv5i5tly be ! type t]m$ a wood base swit*4 ,9 case ! lamp is in/all$ = illum9at+ a clock1 a pe> pu% & a flexible cord may be sub/itut$ = turn+ ! light (f & on 9 place ( ! swit*4 ,x c !n be suitably hung alongside ( ! clock or b$ z desir$4 ,! wire %\ld n be small] ?an ,no4 #ah ,b4 ,s4 ,gauge or else x w (f] too mu* resi/ance to ! electric curr5t & full b5efit ( ! c&le-p[] ( ! lamp w n be secur$4 ,annunciator wire is pref]able4 ,x has good insulation & at ! same "t is n too l>ge to be easily run ?r\gh corn]s1 cracks1 etc4 ,! diagram 9 ,figure #aec %[s h[ to connect ! lamp to ! batt]y & swit*4 ,figure #aef %[s two dry cells connect$ 9 s]ies = use ) a #b4h volt lamp4 ,illu/ration3 ,,fig4 #aec4--;,a ,simple ,light+ ,arrangem5t4 ,:5 m illum9ation is desir$ ?an t furni%$ by fla%light lamps great] c&le-p[] w be requir$4 ,! foll[+ table %[s ! voltages & c&le-p[]s ( ^? lamps :i* are mo/ suitable 9 su* an in/ance3 ,g#f4444d volts #d c&le-p[] ,g#f4444f volts #d c&le-p[] ,g#h #f volts #f c&le-p[] ,!y may also be op]at$ f dry cells4 ,if !y are int5d$ to be 9 use = o!r ?an a few m9utes at a "t x w be well to use a batt]y consi/+ ( two sets ( cells connect$ 9 s]ies multiple4 ,! me?od ( connect+ cells 9 s]ies multiple has already be5 illu/rat$ 9 ,figure #ce4 ,?is w light5 ! /ra9 on ! batt]y & x w be f\nd t two sets ( batt]ies us$ 9 s]ies multiple w la/ 99m ?an twice99 z long z "o set us$ alone4 ,illu/ration3 ,,fig4 #aed4--,%[+ ! diff]5ces betwe5 ! ,c&elabra1 ,s+le ,ediswan & ,d\ble ,ediswan ,types ( ,lamp ,bases4 ,six volt lamps ( m ?an six c&le-p[] are be/ op]at$ on /orage batt]ies because ! curr5t requir$ is too great = dry cells to give effici5t s]vice 9 su* a case4 ,! tung/5 lamps made = automobiles are ideal = m9iature light+ plants op]at$ by /orage batt]ies4 ,! li/ bel[ %[s "s ( ! sizes on a curr5t ( six to eight volts4 ,! bases are made ( brass & come 9 f\r diff]5t /yles1 m9iature1 c&elabra1 s+le ,ediswan & d\ble ,ediswan4 ,! s+le & d\ble ,ediswan are us$ on automobiles because ! con/ruction ( ! base & ! socket or ! receptacle into :i* x fits is su* t ! lamp _c j> loose4 ,illu/ration3 ,,fig4 #aee4--,m9iature ,sockets ( ! types kn[n z ,flat ,base ,porcela91 ,p9 & ,wea!rpro(4 ,! c&elabra base is probably ! type be/ adapt$ to m9iature light+ else:]e ?an on an automobile4 ,! lett] ,g & ! numb] 9 ! fir/ column indicates ! size ( ! glass globe or bulb ( ! lamps4 ,y c compute ! approximate am\nt ( curr5t drawn f a batt]y by a tung/5 lamp1 by divid+ ! c&le-p[] by ! voltage4 ,! result is ! curr5t 9 amp]es4 ,= example1 a #f volt1 #ab c&le-p[] lamp w consume #ab divid$ by #f1 or #b amp]es4 ,illu/ration3 ,,fig4 #aef4--;,connections = a #b4h ,volt ,lamp4 ,/orage batt]ies are rat$ by _! output 9 99amp]e h\rs994 ,an amp]e h\r is ! am\nt ( curr5t repres5t$ by "o amp]e fl[+ = "o h\r4 ,a =ty amp]e h\r cell w deliv] "o amp]e = =ty h\rs1 #d amp]es = t5 h\rs or #e amp]es = eight h\rs4 ,! amp]e h\r capacity ( a /orage cell divid$ by ! am\nt ( curr5t be+ us$ w det]m9e h[ long t curr5t c be drawn be=e re*>g+ is necess>y4 ,! maximum am\nt ( curr5t x is safe to draw f a /orage cell )\t impair+ its life & effici5cy is ! maximum curr5t :i* t cell c deliv] cont9u\sly = eight h\rs4 ,9 ord] to det]m9e ?is curr5t simply divide ! manufactur]'s rat+ ( ! batt]y 9 amp]e h\rs by eight4 ,! answ] is ! maximum curr5t y %\ld require f ! batt]y if y wi% to obta9 good s]vice f x4 ,= example1 ! maximum safe dis*>ge rate ( a #dj amp]e h\r batt]y is #dj divid$ by #h or #e amp]es4 ,illu/ration3 ,,fig4 #aeg4--;,a ,m9iature ,base ,tung/5 ,filam5t ,batt]y ,lamp = small light+4 ,! me?od ( comput+ ! curr5t requir$ by a lamp & ! me?od = det]m9+ ! maximum safe dis*>ge rate ( a batt]y w enable y to figure ! size ( ! smalle/ batt]y x is desirable to use 9 a light+ plant4 ,suppose t y int5d to use ?ree #f volt #ab c&lep[] lamps4 ,ea* lamp w require two amp]es or a total ( six :5 all ?ree lamps are burn+ at ! same "t4 ,six amp]es multipli$ by eight amp]e h\rs equals #dh amp]e h\rs4 ,?is is ! smalle/ size ( batt]y :i* %\ld be us$4 ,if x is l>g]1 x w be advantage\s1 because x w supply ! lamps a correspond+ly long] "t )\t re*>g+4 ,figure #aee %[s "s ( ! sockets or receptacles :i* are on ! m>ket4 ,! illu/ration to ! left is a flat base receptacle4 ,x w be f\nd mo/ useful :5 ! lamp is to be m\nt$ directly on ! wall or ceil+4 ,! wea!rpro( type ( socket may be secur$ ) ei!r a fibre or a porcela9 %ell4 ,illu/ration3 ,,fig4 #aeh4--;,a ,tung/5 ,automobile ,lamp ) ,ediswan ,base4 ,! brass %ell socket is ! be/ :]ev] appe>ance c\nts4 ,x is patt]n$ aft] ! /&>d ,edison sockets & is made s t x w screw onto sev]al diff]5t sizes & /yles ( brackets :i* may be m\nt$ on ei!r ! ceil+ or ! wall4 ,?is type ( socket is also made ) a small swit* built inside s t ! lamp may be turn$ on or (f directly at ! socket4 99,! ,wire99 us$ to connect ! sy/em w dep5d ^u :]e ! lamps are locat$4 ,annunciator or (fice wire z x is sometimes call$ w s]ve 9 mo/ cases :]e ! wires are to be run entirely indoors4 ,! l>ge/ size made is ,no4 #af ,b4 ,s4 ,gauge4 ,?is is ! size :i* %\ld be us$4 ,annunciator wire is made 9 v>i\s colors s t x c be m easily conceal$4 ,if ! wires are run outdoors1 or some:at expos$ to ! wea!r1 z on a por* or 9 a b>n1 x is advisable to use wea!rpro( or rubb] cov]$ wire4 ,lead cov]$ tw9 conductor is recomm5d$ = use abo>d boats or :]ev] ! wire is liable to abrasion4 ,illu/ration3 ,,fig4 #aei4--,lamps ,controll$ by ,"o ,swit*4 ,if ! lamps are l>g] ?an eight c&le-p[]1 or sev]al are to be us$ on ! same l9e1 ! wires %\ld be l>g] ?an ,no4 #af4 ,:5 a batt]y is connect$ to a sy/em ( wires1 ! voltage at ! end ( ! l9e is mu* l[] ?an x is at ! batt]y t]m9als4 ,?is is due to ! resi/ance ( ! wire & is call$ voltage drop4 ,! lamps at ! end ( ! l9e w n burn z brilliantly z ^? close to ! batt]y4 ,?is c be p>tially ov]come by us+ l>ge wire4 ,! lamps may be ei!r connect$ 9 s]ies or 9 multiple4 ,:5 a six volt batt]y is us$1 x w be necess>y to connect !m 9 multiple4 ,figure #aei %[s h[ sev]al lamps may be connect$ 9 multiple & controll$ by "o swit*4 ,figure #afj %[s ! same lamps ) ?ree sep>ate swit*es s t ea* lamp may be turn$ on or (f individually4 ,illu/ration3 ,,fig4 #afj4--,lamps ,controll$ by ,sep>ate swit*es4 ,x is possible to arrange a lamp & two swit*es s t x c be turn$ on or (f at ei!r swit* indep5d5tly ( ! o!r4 ,?is is a v conv5i5t me?od ( in/all+ a light on a /airway or 9 a hall4 ,"o swit* may be plac$ at ! top ( ! /airs & ! o!r at ! bottom4 ,a p]son go+ ei!r up or d[n /airs c light ! lamps ahead & turn x out z he passes ! la/ swit* reg>dless ( its position at ! o!r end4 ,! swit*es mu/ be ( ! type call$ two po9t or d\ble ?r[ s+le pole & ! lev]s mu/ always re/ on "o ( ! contacts & nev] be left 9 betwe54 ,illu/ration3 ,,fig4 #afa4--;,d\ble ,control ,sy/em4 ,,*apt] ,,xvi4 ,,coh]] ,,outfits ,,= ,,wireless ,,telegraphy4 ,mak+ a ,coh]]4 ,h[ to ,adju/ ! ,in/rum5ts4 ,,_m exp]im5t]s desire "s device by :i* wireless signals may be made cle>ly audible )\t ! necessity ( hold+ a telephone receiv] to ! e>4 ,x is n possible = ! amateur to make su* an arrangem5t :i* w receive signals ov] long di/ances4 ,x is1 h[ev]1 possible to arrange a coh]] s t signals com+ f a ne>by /ation may be indicat$ by ! r++ ( a bell4 ,illu/ration3 ,,fig4 #afb4--,! ,coh]] ,details4 ,su* a coh]] outfit w receive messages com+ )9 a radius ( "o mile & may also be us$ = demon/rat+ ! pr9ciples ( wireless telegraphy :5 bo? ! receiv+ & transmitt+ /ation are locat$ 9 ! same room or build+4 ,9 ord] to secure ^! results x w be necess>y to sub/itute a device call$ a coh]] = ! detector 9 ! receiv+ app>atus4 ,a coh]] consi/s ess5tially ( a few metal fil+s betwe5 two metal plugs4 ,! fil+s are made "p ( a circuit :i* includes a relay & a batt]y4 ,"u ord9>y conditions ! fil+s lie loosely toge!r & _! resi/ance to an electric curr5t is s great t !y w n all[ en\gh en]gy to fl[ to op]ate ! relay4 ,if1 h[ev]1 ! two plugs are connect$ to ! a]ial & gr\nd s t ! curr5ts ( ! incom+ wireless signals also pass ?r\gh ! fil+s1 !y w sudd5ly coh]e or /ick toge!r & p]mit suffici5t curr5t to pass to op]ate ! relay4 ,illu/ration3 ,,fig4 #afc4--,! ,complete ,coh]]4 ,a tapp]1 or z x is also sometimes call$ a decoh]]1 is also arrang$ 9 ! circuit s z to automatically %ake ! fil+s up & re/ore !m to _! loose /ate z soon z ea* signal is receiv$4 ,! decoh]] consi/s simply ( an ord9>y bell m\nt$ s t ! hamm] w /rike ! coh]] & j> x4 ,! fir/ ?+ requir$ 9 ord] to make a coh]] is a pair ( d\ble b9d+ po/s4 ,^! %\ld be m\nt$ on a wood5 base six in*es long & f\r in*es wide z %[n 9 ,figure #afc4 ,a piece ( glass tub+ ab\t "o & "o-half in*es long & "o-eigh? ( an in* 9 diamet] inside toge!r ) "s brass rod :i* w j slip into ! tube tightly w be requir$4 ,cut two pieces ( ! brass rod "o & ?ree-qu>t]s in*es long & face (f ! ends p]fectly squ>e & smoo?4 ,slip ^! rods ?r\gh ! upp] holes 9 ! b9d+ po/s & into ! glass tube z %[n 9 ,figure #afc4 ,be sure t ev]y?+ l9es up p]fectly & !n remove "o ( ! plugs4 ,be=e putt+ ! plug back 9 place put "s nickel & silv] fil+s 9 ! tube s t :5 ! rods are pu%$ almo/ toge!r1 ) only a di/ance ( ?ree-sixty-f\r?s to "o-sixte5? ( an in* betwe51 ! fil+s w ab\t half fill ! space4 ,illu/ration3 ,,fig4 #afd4--,pony ,type ,relay4 ,! fil+s are a mixture ( silv] & nickel & mu/ be v c>efully prep>$4 ,! mixture %\ld be n9e-t5?s nickel & "o-t5? silv]4 ,! fil+s may be secur$ by hold+ a five c5t piece ov] a clean %eet ( pap] & fil+ x ) a co>se file4 ,! silv] fil+s are made 9 ! same way by us+ a t5 c5t piece or a qu>t] 9 place ( ! nickel4 ,d n use ! f9e du/ & p[d] :i* is =m$1 b only ! co>se fil+s4 ,! success ( ! coh]] w dep5d ^u its adju/m5t & x w probably be necess>y = ! beg9n] to exp]im5t consid]ably to f9d out j ! "r am\nt ( fil+s to place 9 ! tube & h[ f> ap>t ! brass plugs %\ld be plac$4 ,! decoh]] is made by remov+ ! gong f an old electric bell & m\nt+ ! bell on ! base 9 ! position %[n 9 ,figure #afc4 ,! hamm] %\ld be b5t s t x w tap ! coh]] lightly :5 a batt]y is connect$ to ! bell b9d+ po/s4 ,! only ?+ requir$ to complete ! app>atus is a relay4 ,a relay ( ! ,pony type su* z t %[n 9 ,figure #afd w s]ve = ord9>y "w4 ,x %\ld be w\nd to at lea/ #aej ohms1 = to a c]ta9 ext5t1 ! high] ! resi/ance1 ! m s5sitive x w be4 ,:5 x is desir$ to secure ! maximum possible di/ance ) ! coh]] a pol>iz$ relay w be necess>y4 ,a pol>iz$ relay is mu* m s5sitive ?an ! ord9>y sort4 ,! pol>iz$ relay %\ld be w\nd to #ajjj ohms4 ,illu/ration3 ,,fig4 #afe4--;,connections = ! ,receiv+ ,set4 ,figure #afe illu/rates h[ ! coh]]1 decoh]] & relay %\ld be connect$4 ,two wires connect$ to ! coh]] po/s lead to ! magnets ( ! relay 9 s]ies ) a s+le dry cell4 ,! contact posits ( ! relay are connect$ to ! decoh]] 9 s]ies ) ano!r dry cell4 ,:5 wireless signals pass ?r\gh ! relay !y w cause ! resi/ance to drop & all[ suffici5t curr5t f ! dry cell to pass ?r\gh ! coh]] to en]gize ! magnets ( ! relay & draw ! armature 91 ?us clos+ ! decoh]] circuit4 ,:5 ! armature ( ! relay is drawn 9 t[>ds ! magnets ! relay contacts are br\ght toge!r4 ,?is closes ! decoh]] circuit & />ts ! hamm] to tapp+ ! coh]]1 ?us re/or+ ! fil+s to _! =m] loose /ate4 ,! decoh]] w tap ! coh]] z long z ! incom+ signals cont9ue4 ,by break+ ! signals up into dots & da%es ( ! telegraph code a message may be easily transmitt$ & read f ! tapp+ ( ! decoh]]4 ,illu/ration3 ,,fig4 #aff4--;,coh]]1 ,decoh]] & ,relay ,connections4 ,! be/ results are secur$ f a coh]] outfit if x is connect$ to ! a]ial & gr\nd by sub/itut+ x = ! detector 9 a circuit employ+ a d\ble slide tun+ coil & a fix$ cond5s]4 ,! two wires t w\ld ord9>ily be connect$ to ! detector t]m9als are simply connect$ to ! coh]] po/s4 ,:5 ! app>atus is to be us$ = demon/ration or exp]im5t & ! transmitt+ & receiv+ /ations are bo? locat$ 9 ! same room or h\se x w n be necess>y to use an a]ial & gr\nd b m]ely to atta* two copp] wires ab\t #ah or #bd in*es long to ! opposite sides ( ! coh]] z %[n 9 ,figure #afc4 ,9 su* a case ! transmitt] %\ld be arrang$ z 9 ,figure #afg4 ,a sp>k gap made especially = ?is purpose is illu/rat$ 9 ,figure #afh4 ,"s ( ! details ( ! gap are %[n 9 ,figure #afi4 ,illu/ration3 ,,fig4 #afg4--;,h[ ! ,transmitt] is ,connect$4 ,! ball may be made 9 ! =m ( a complete sph]e or else consi/ simply ( half ( "o z illu/rat$4 ,x %\ld h a radius ( ab\t five-eigh?s ( an in* & arrang$ s t x may be m\nt$ ^u ! end ( a cat*-wire4 ,illu/ration3 ,,fig4 #afh4--,! ,complete ,sp>k ,gap4 ,! cat*-wires are m\nt$ 9 two /&>ds simil> 9 con/ruction to a l>ge b9d+ po/ ?ree & "o-qu>t] in*es high4 ,! /&>ds %\ld be m\nt$ by screw+ !m on top ( ! second>y t]m9als ( ! sp>k coil4 ,! sp>k balls %\ld be adju/$ s t ! di/ance betwe5 !m is n ov] "o-eigh? ( an in*4 ,! coh]] app>atus w probably require to be v accurately adju/$ be=e x w "w prop]ly4 ,pati5ce & a little exp]i5ce w soon enable "o to ov]come ! difficulties & to put ! app>atus 9 s5sitive condition )\t mu* tr\ble4 ,illu/ration3 ,,fig4 #afi4--;,details ( ,sp>k ,gap4 ,! coh]] w be f\nd to be ! mo/ s5sitive :5 only a v few fil+s are us$4 ,! adju/m5t desir$ 9 ! relay is ! "o 9 :i* ! armature is giv5 ! smalle/ possible am\nt ( motion & ! spr+ :i* pulls ! armature away f ! magnets1 ! lea/ t5sion4 ,! be/ me?od ( f9d+ ! mo/ s5sitive adju/m5t = ! app>atus is to place ! transmitt+ & receiv+ /ations only a few feet ap>t f ea* o!r 9 ! same room4 ,aft] y le>n h[ to adju/ ! coh]] & relay prop]ly y w !n f9d t y c move ! transmitt] q a di/ance away f ! coh]] & x w /ill op]ate4 ,( c\rse a coh]] outfit is n v satisfactory & reliable = ! regul> reception ( wireless signals ev5 ov] %ort di/ances because ( its irregul> work+4 ,x is1 h[ev]1 v useful = sort ( a call+ or signal outfit4 ,x may be connect$ to ! tun+ coil by means ( a d\ble-pole1 d\ble-?r[ swit* & left 9 ! circuit s z to indicate by ! work+ ( ! tapp] :5 any ( ! o!r /ations 9 ! ne> neighborhood are s5d+4 ,! detector c !n be quickly ins]t$ 9 ! circuit 9 place ( ! coh]] by ?r[+ ! swit* 9 ! opposite direction & ! signals read 9 ! telephone receiv]4 ,,*apt] ,,xvii4 ,,h[ ,,to ,,build ,a ,,tesla ,,high ,,frequ5cy ,,coil4 ,,if ! dis*>ge f a ,leyd5 j> or a cond5s] is pass$ ?r\gh a coil ( wire act+ z a prim>y & ! prim>y is provid$ ) a second>y coil ( a l>g] numb] ( turns1 a peculi> curr5t kn[n z high frequ5cy electricity is g5]at$ 9 ! second>y4 ,su* a device is kn[n z a ,tesla ,coil or ,trans=m]4 ,illu/ration3 ,,fig4 #agj4--,tesla ,coil ,circuits4 ,:5 a ,leyd5 j> or a cond5s] dis*>ges ?r\gh a coil ( wire1 ! sp>k :i* takes place does n consi/ simply ( a s+le sp>k pass+ 9 "o direction only1 b is really made ( a numb] ( sep>ate sp>ks pass+ alt]nately 9 opposite directions at ! trem5d\s rate ( f "o hundr$ ?\s& to "o million times p] second4 ,a ,tesla high frequ5cy coil op5s a field ( wond]ful possibilities to ! amateur exp]im5t] & br+s innum]able weird & fasc9at+ exp]im5ts )9 8 rea*4 ,! ,tesla coil describ$ 9 ! foll[+ pages w give sp>ks ( high frequ5cy electricity two or ?ree in*es long f ! second>y1 :5 us$ 9 connection ) a two in* sp>k induction coil4 ,if us$ 9 connection ) a small high pot5tial wireless trans=m]1 ! high frequ5cy dis*>ge c be increas$ to six or eight in*es4 ,a ,tesla coil1 suitable = use ) a small] sp>k coil1 say "o capable ( giv+ sp>ks f "o-half to "o in* 9 l5g? c be made by foll[+ ! same plans b cutt+ all ( ! dim5sions 9 half4 ,make ! second>y six in*es long & "o & "o-half in*es 9 diamet] in/ead ( twelve in*es long & ?ree in*es 9 diamet]1 etc4 ,illu/ration3 ,,fig4 #aga4--,second>y ,tube4 99,! ,second>y99 w9d+ consi/s ( a s+le lay] ( ,no4 #bh ,b4 ,s4 ,gauge d\ble cotton cov]$ wire w\nd ov] a c>dbo>d tube1 twelve in*es long & & ?ree in*es 9 diamet]4 ,! tube mu/ be ?or\ghly dri$ be=e us+ x1 by bak+ 9 an ov54 ,a coat ( %ellac1 bo? inside & out1 w avoid ! possibility ( hav+ to rew9d ! tube because ( ! wire becom+ loose1 due to dry+ out ( ! tube lat]4 ,! wire %\ld be w\nd on 9 a smoo?1 ev5 lay] to )9 ab\t "o-qu>t] ( an in* f ! ends & giv5 a coat ( hot p>aff9e :5 f9i%$4 ,! ends ( ! tube are fitt$ ) circul> wood5 heads hav+ a half in* flange4 99,! ,base99 is a rectangul> piece ( wood1 fifte5 in*es long & six in*es wide4 ,! second>y is support$ 9 position by two h>d rubb] uprights1 f\r in*es high1 sev5-eigh?s ( an in* wide & "o-half an in* ?ick4 ,a r\nd-head$ brass wood screw is pass$ ?r\gh ! top "p ( ea* ( ! supports into ! c5tre ( ea* "o ( ! wood5 second>y heads4 ,high frequ5cy curr5ts are v h>d to insulate & wood does n possess suffici5t insulat+ value to fit x = use z supports4 ,h>d rubb] or glass are ! mo/ satisfactory mat]ials = ! supports4 ,illu/ration3 ,,fig4 #agb4--;,details ( ! ,second>y ,heads4 ,! second>y t]m9als are connect$ to two brass rods1 five in*es long & hav+ a small brass ball at ! upp] end1 m\nt$ on ! top ( ea* ( ! h>d rubb] supports4 ,! l[] ends ( ! h>d rubb] supports are fa/5$ to ! base by means ( screws pass+ upw>ds ?r\gh ! base into a ?read$ hole 9 ! bottom ( ea* support4 ,illu/ration3 ,,fig4 #agc4--;,details ( ! ,prim>y ,head4 ,! second>y passes ?r\gh ! c5tre ( ! prim>y4 ,! prim>y consi/s ( eight turns ( heavy copp] wire w\nd ar\nd a wood5 drum or frame4 ,! wire %\ld be ,no4 #h or ,no4 #aj ,b4 ,s4 ,gauge4 ,flat copp] or brass ribbon "o-qu>t] ( an in* wide c be us$ 9 place ( ! wire4 ,! /r&$ copp] wire1 consi/+ ( sev5 ,no4 #bb ,b4 ,s4 ,gauge wires twi/$ toge!r & commonly employ$ = wireless a]ials c be us$ to good advantage 9 w9d+ ! prim>y1 ! idea ( us+ a l>ge wire1 /r&$ wire1 or ribbon be+ to obta9 a conductor hav+ z mu* surface z possible4 ,high frequ5cy curr5ts travel only on ! surface ( wires & conductors4 ,a holl[ tube is j z good a conductor = high frequ5cy curr5ts z a solid rod ( ! same diamet]4 ,illu/ration3 ,,fig4 #agd4--,prim>y ,cross ,b>4 ,illu/ration3 ,,fig4 #age4--;,front ,view ( ! complet$ ,tesla ,coil4 ,illu/ration3 ,,fig4 #agf--,side ,view ( ! complet$ ,tesla ,coil4 ,! heads ( ! prim>y drum are wood5 r+s1 sev5 in*es 9 diamet] outside1 f\r & "o-half in*es inside & "o-half an in* ?ick4 ,six cross b>s1 two & "o-half in*es long1 ?ree-qu>t]s ( an in* ?ick & "o-half an in* wide are requir$ to support ! wire4 ,!y are spac$ equidi/antly ar\nd ! r+s & held 9 position by means ( brass screws pass+ ?r\gh ! r+s4 ,d n use iron screws1 because iron is magnetic & %\ld be entirely avoid$ 9 ! con/ruction ( a ,tesla coil4 ,small not*es %\ld be cut 9 ! outside edge ( ! cross b>s to accommodate ! wires4 ,! wires %\ld pass ar\nd ! drum 9 ! =m ( a spiral ) "o-qu>t] to five-sixte5?s ( an in* space betwe5 ! turns4 ,! complet$ drum w some:at resemble a squirrel cage4 ,! ends ( ! prim>y w9d+ %\ld t]m9ate 9 two l>ge b9d+ po/s m\nt$ on ! prim>y heads4 ,! heads are fa/5$ to ! c5tre ( ! base by a c\ple ( l>ge wood screws pass+ upw>ds ?\gh ! bottom4 ,illu/ration3 ,,fig4 #agg4--;,diagram ( connections = op]at+ ! ,coil4 ,! illu/ration 9 ,figure #agg %[s h[ to connect ! ,tesla coil4 ,! prim>y %\ld be 9 s]ies ) a cond5s] & a sp>k gap4 ,! cond5s] %\ld consi/ ( two or ?ree ,leyd5 j>s or sev]al glass plates coat$ ) t9foil4 ,x is impossible to det]m9e j h[ mu* capacity ! cond5s] %\ld h 9 advance1 because ! l5g? ( ! conduct+ wires1 adju/m5t ( ! sp>k gap1 etc41 w h consid]able effect4 ,! cond5s] is connect$ directly across ! t]m9als ( ! sp>k coil4 ,! sp>k gap may consi/ ( two "o-eigh? in* brass rods support$ by two d\ble b9d+ po/s m\nt$ on a small wood5 block4 ,! induction coil %\ld be z l>ge z possible4 ,:5 ! coil is set 9 op]ation x w *>ge ! cond5s] & a :ite1 snappy sp>k %\ld pass across ! gap4 ,if ! f+]s are br\ght ne> to "o ( ! second>y t]m9als ( ! ,tesla coil1 a small1 r$di% purple sp>k w jump out to meet !m4 ,x w be necess>y to adju/ ! app>atus v c>efully be=e a sp>k ( any consid]able l5g? c be obta9$4 ,*ang+ ! l5g? ( ! sp>k gap & ! size ( ! cond5s] w und\bt$ly produce results4 ,x may also be possible to l5g!n ! high frequ5cy sp>k by disconnect+ "o ( ! wires f ! prim>y b9d+ po/s on ! ,tesla coil & connect+ ! wire directly to "s "o ( ! prim>y turns4 ,a v small *ange 9 "s "o ( ! connections may produce consid]able result4 ,! purpose ( ! adju/m5ts is to tune ! circuit 9 ! same mann] t a wireless outfit is tun$ by alt]+ ! capacity ( ! cond5s] or v>y+ ! numb] ( turns 9 ! helix4 ,illu/ration3 ,,fig4 #agh4--,plate ,glass ,cond5s]4 ,!re are _m int]e/+ exp]im5ts :i* may be p]=m$ ) ! aid ( a ,tesla coil :i* space does n p]mit ( describ+ "h4 ,! weird & /range beauty ( ! ,tesla dis*>ge is mo/ evid5t :5 x takes place 9 ! d>k4 ,high frequ5cy curr5ts d n produce a %ock4 ,if y hold a piece ( metal 9 y\r h& & br+ x ne> "o ( ! second>y t]m9als1 y c take ! %ock ( a high-frequ5cy coil1 ?r[+ a sp>k sev]al in*es long )\t feel+ any s5sation except t ( a slight w>m?4 ,,*apt] ,,xviii4 ,,an ,,exp]im5tal ,,wireless ,,telephone4 ,_m ( ! read]s ( ?is book are probably wireless exp]im5t]s :o h con/ruct$ _! own wireless telegraph app>atus1 b n _m h ev] built a wireless telephone set4 ,! arrangem5t describ$ 9 ! foll[+ *apt] may be built by almo/ any boy & w prove a v int]e/+ & in/ructive piece ( app>atus4 ,x is ( no real practical value z a wireless telephone1 ow+ to ! fact t ! di/ance ov] :i* x w transmit intelligible spee* is limit$ to #aej to #cjj feet4 ,h[ev] if y h a *um :o lives next door or across ! /reet or )9 ! di/ance nam$ above1 x is easily possible = y to con/ruct a wireless telephone :i* w enable y to rema9 9 y\r own rooms & hold a conv]sation ) ea* o!r1 )\t any connect+ wires4 ,illu/ration3 ,,fig4 #agi4--,:5 a ,b> ,magnet is plung$ into a ,holl[ ,coil ( ,wire1 a ,mom5t>y ,curr5t ( ,electricity is ,g5]at$4 ,! in/rum5ts dep5d = op]ation ^u :at is kn[n z magnetic induction4 ,mi*ael ,f>aday1 :o 0 a fam\s ,engli% sci5ti/1 discov]$ 9 #ahca t if a magnet is sudd5ly plung$ into a holl[ coil ( wire1 a mom5t>y curr5t ( electricity is g5]at$ 9 ! coil4 ,y c try ?is exp]im5t = y\rself by connect+ a galvanomet] ) a holl[ coil ( wire & !n sudd5ly plung+ a b> magnet into ! coil4 ,if y obs]ve closely y w notice t ! ne$le ( ! galvanomet] is deflect$1 ?is indicat+ t a curr5t has pass$ ?r\gh ! circuit4 ,! galvanomet] %\ld ( c\rse be f> en\gh away s t ! ne$le is n affect$ directly by ! magnetism ( ! b> magnet itself4 ,illu/ration3 ,,fig4 #ahj4--,magnetic ,phantom %[+ ! ,l9es ( ,=ce ab\t a ,b> ,magnet4 ,z long z ! b> magnet is motionless1 x w n induce any curr5t 9 ! coil4 ,z soon z x is mov$ h[ev]1 ! curr5ts are set up4 ,! me*anical "w done 9 mov+ ! magnet is really ! s\rce ( electrical en]gy4 ,! m$ium :i* *anges ! me*anical en]gy into electricity is call$ ! magnetic field4 ,! real nature ( a magnetic field is v h>d to expla9 & n easily und]/ood4 ,x is a peculi> /ate or condition ( ! space 9 ! imm$iate neighborhood ( a magnet4 ,x is possible to %[ its exi/5ce by plac+ a %eet ( c>dbo>d ov] a magnet & !n spr9kl+ iron fil+s ov] ! surface ( ! c>dbo>d4 ,if ! c>dbo>d is tapp$ slightly1 ! fil+s w settle d[n 9 curv+ l9es1 =m+ a magnetic phantom4 ,! curv$ l9es into :i* ! fil+s =m !mselves1 repres5t ! pa?s ( ! l9es ( =ce :i* make up ! magnetic field4 ,! illu/ration 9 ,figure #ahj %[s ! magnetic phantom ab\t a b> magnet4 ,:5 ! space 9 ! neighborhood ( a wire or a coil ( wire ?r\gh :i* a curr5t ( electricity is pass+ is exam9$ by means ( "s iron fil+s spr9kl$ on a %eet ( c>dbo>d1 x is f\nd t a simil> /ate ( affairs exi/s !re & t x also possesses a magnetic field4 ,?is c be readily %[n by pun*+ a small hole 9 ! c5tre ( a %eet ( c>dbo>d or /iff pap] & pass+ a wire :i* is c>ry+ a /rong curr5t ( electricity ?r\gh ! hole at "r angles to ! surface ( ! c>dbo>d4 ,spr9kle "s iron fil+s on ! c>dbo>d & !y w arrange !mselves 9 circles ar\nd ! wire1 =m+ a magnetic phantom giv+ def9ite pro( to ! eyes ( ! exi/5ce ( ! magnetic field4 ,"s ( my read]s may h begun to wond] :at a magnetic field has to d ) ! op]ation ( ! wireless telephone4 ,x has already be5 expla9$ t ?is p>ticul> type ( wireless telephone dep5ds ^u magnetic induction = its op]ation4 ,x is necess>y to h "s sort ( a conception ( ! magnetic field be=e y w be able to und]/& magnetic induction4 ,illu/ration3 ,,fig4 #aha4--,magnetic ,phantom ab\t a ,coil ( ,wire c>ry+ a curr5t4 ,9 ord] t y may ga9 an idea ( h[ ! in/rum5ts "w1 suppose t two coils ( wire1 ,a & ,b1 are connect$ z %[n 9 ,figure #ahb4 ,! coil ,a is connect$ 9 s]ies ) a set ( batt]ies & a telegraph key4 ,! o!r coil ,b is connect$ to a telephone receiv]4 ,! coils are plac$ p>allel to ea* o!r & only a few in*es ap>t4 ,:5 ! key is press$ s t ! circuit is complete & ! batt]y curr5t fl[s ?r\gh ! coil ,a1 x creates a magnetic field 9 ! vic9ity ( ! coil & l9es ( =ce are set up 9 ! imm$iate neighborhood4 ,! l9es ( =ce w travel ?r\gh & ab\t coil ,b & 99induce 9 x a curr5t ( electricity994 ,! electric curr5t w cause a s\nd l a click 9 ! telephone receiv]4 ,:5 a telephone transmitt] is sub/itut$ = ! key & words are spok5 into ! m\?piece1 ! curr5t pass+ ?r\gh ! coil f ! batt]y w be v>i$ 9 accordance ) ! vibrations ( ! voice4 ,! *anges 9 ! curr5t w produce *anges 9 ! magnetic field set up by ! coil & ! *anges 9 ! magnetic field w produce a v>y+ curr5t 9 ! coil ,b s t ! words w be di/9ctly repeat$ by ! receiv] connect$ to ,b4 ,illu/ration3 ,,fig4 #ahb4--;,illu/rat+ ! ,pr9ciple ( ! ,induction ,wireless ,telephone4 ,?is exp]im5t is v easy to p]=m & may be c>ri$ out by almo/ any boy ) ! mat]ials he probably already has ar\nd 8 %op4 ,tw5ty-five to ?irty turns ( magnet wire ( almo/ any size w\nd ar\nd "o end ( a c>dbo>d tube ?ree or f\r in*es 9 diamet] w s]ve z ! coil ,a4 ,a simil> coil w\nd ar\nd ! tube five or six in*es away1 an ord9>y telephone transmitt] & receiv] & two or ?ree dry cells =m all ! re/ ( ! equipm5t desir$4 ,words spok5 into ! transmitt] connect$ to ! coil ,a w be di/9ctly he>d 9 ! telephone receiv] connect$ to ! coil ,b1 al?\gh !re is no connection betwe5 ! two coils o!r ?an ! 99magnetic field994 ,su* an outfit z ?is is ( c\rse only exp]im5tal & int5d$ solely = ! purpose ( demon/rat+ ! pr9ciples ( op]ation ( ! l>g] outfit4 ,if x is desir$ to make a practical set = talk+ ov] a consid]able di/ance x w be necess>y to make coils mu* l>g] 9 diamet] & to build !m s !y conta9 a l>g] numb] ( turns4 ,illu/ration3 ,,fig4 #ahc4--,%[+ h[ ! ,coils may be =m$ by w9d+ ar\nd nails set 9 a circle 9 ! ,floor4 ,l>ge coils c be made by draw+ a circle ab\t f\r feet 9 diamet] on ! floor ( y\r %op4 ,!n drive a numb] ( small nails ar\nd ! circle ab\t ?ree in*es ap>t4 ,?is arrangem5t w s]ve z a =m to w9d ! coil4 ,aft] ! w9d+ is complet$ y c pull a few ( ! nails out & lift x (f & y w h a circul> coil f\r feet 9 diamet]4 ,two coils w be requir$4 ,!y %\ld be made ( ,no4 #bj ,b4 ,s4 ,gauge cotton cov]$ wire4 ,ea* coil %\ld conta9 ab\t sev5ty-five turns ( wire4 ,ab\t ?ree p\nds ( wire w be requir$ = ea* coil4 ,aft] w9d+ ! coils %\ld be ti$ ) /r+ or tape ab\t e six in*es s t !y w n come ap>t4 ,! nails c !n be pull$ out ( ! floor & ! coil is ready = use4 ,if x is int5d$ to subject ! coils to any am\nt ( h&l+1 x is a good idea to secure two l>ge hoops su* z girls use = roll+ along ! sidewalk1 ab\t f\r feet 9 diamet]4 ,!n make ! coils exactly ! same diamet] z ! hoops & :5 !y are f9i%$ b9d !m to ! hoops ) tape4 ,two b9d+ po/s may be m\nt$ on ea* ( ! hoops & ! t]m9als ( ! coil connect$ to !m4 ,two coils are requir$ 9 ord] to e/abli% a complete wireless telephone sy/em1 "o at ea* /ation4 ,ea* coil may be us$ = bo? s5d+ & receiv+ messages4 ,ea* /ation %\ld be arrang$ z 9 ,figure #ahd4 ,! transmitt] %\ld be ( ! type kn[n z long di/ance4 ,! swit* is a two po9t swit*4 ,illu/ration3 ,,fig4 #ahd4--;,circuit ,diagram %[+ h[ ! ,coil is connect$ s z to s]ve = ei!r transmitt+ or receiv+4 ,x is a good plan to use two telephone receiv]s m\nt$ on a head b& s t bo? e>s c be us$ & ! h&s left free to manipulate ! swit*4 ,if a set ( telephone receiv]s w\nd to a high resi/ance = wireless telegraph purposes is us$ x w greatly increase ! range ( ! outfit4 ,six to eight fir/ class dry cells w be requir$ to =m ! batt]y4 ,a pu% button is plac$ 9 s]ies ) ! transmitt] s t ! batt]y curr5t w be consum$ only :5 ! button is press$4 ,?is makes x necess>y to pu% ! button :5 s5d+ a message4 ,:5 ! lev] ( ! two po9t swit* re/s on ! contact ,a ! circuit is complet$ = transmitt+4 ,:5 ! lev] re/s on ,b ! telephone receiv]s are connect$ to ! coil & ! app>atus is ready = receiv+ a message4 ,if ! app>atus is us$ only = demon/rat+ purposes1 a cam]a tripod w be f\nd v conv5i5t = support+ ! coils4 ,! transmitt] & swit* c be fa/5$ to ! top ( ! tripod & ! batt]ies plac$ 9 a box on ! gr\nd4 ,x is absolutely necess>y t ! coils be p]fectly p>allel to ea* o!r :5 messages are be+ transmitt$ back & =?4 ,x is well to />t ) ! coils comp>atively close to ea* o!r1 say t5 or twelve feet at fir/1 & !n gradually increase ! di/ance4 ,coils approximately f\r feet 9 diamet] & conta9+ ab\t sev5ty-five turns ( wire w transmit & receive messages ab\t "o hundr$ & fifty feet4 ,! range c be increas$ slightly by us+ m batt]ies4 ,if too mu* batt]y is us$1 h[ev]1 ! telephone transmitt] w become v hot & is liable to burn out4 ,x is impossible1 ( c\rse1 to call up ov] a set ( wireless phones su* z ^!4 ,if y succe$ 9 gett+ y\r set to "w satisfactorily ) y\r *um across ! /reet & wi% to talk to him x w be necess>y = y to arrange "s pr$et]m9$ "t4 ,9 ord] to op]ate y\r phone place ! swit* lev] on ! contact ,a4 ,hold y\r f+] tightly aga9/ ! pu% button s t ! circuit is complet$ & talk sl[ly & di/9ctly into ! transmitt]4 ,! transmitt] w op]ate ! be/ :5 ! m\?piece po9ts on a level ) y\r m\?4 ,! lips %\ld be ab\t "o in* away f ! m\?piece4 ,speak 9 a l[ ev5 tone4 ,! swit* at y\r fri5d's /ation %\ld be re/+ on ,b4 ,:5 y f9i% speak+ ?r[ y\r swit* to ,b & li/5 9 y\r telephone receiv]s4 ,! op]ator at ! o!r /ation %\ld ?r[ 8 swit* to ,a & pu% ! button4 ,he may !n talk to y4 ,,*apt] ,,xix4 ,,miscellane\s ,,exp]im5ts ,,& ,,app>atus4 ,,electrolysis4 ,liquid :i* w conduct a curr5t ( electricity is call$ an 99electrolyte994 ,all electrolytes are comp\nds1 t is1 !y consi/ ( m ?an "o sub/ance4 ,:5 an electric curr5t passes ?r\gh a liquid x decomposes x4 ,?is process ( decomposition is call$ 99electrolysis994 ,pure wat] is n a conductor ( electricity4 ,if sulphuric acid is add$ to wat]1 ! mixture become an electrolyte & w conduct4 ,if an electric curr5t is pass$ ?r\gh wat] conta9+ sulphuric acid1 x w decompose ! wat]4 ,illu/ration3 ,,fig4 #ahe4--;,app>atus = ,electrolysis ,exp]im5t4 ,wat] is compos$ ( oxyg5 & hydrog5 & s bubbles ( oxyg5 & hydrog5 gas w rise f ! liquid4 ,figure #ahe illu/rates a v simple arrangem5t = decompos+ acidulat$ wat] into oxyg5 & hydrog5 gases4 ,x consi/s ( a bottle ) ! bottom brok5 out1 & provid$ ) a cork fitt$ snugly into ! neck4 ,two glass tubes pass ?r\gh ! cork4 ,a small piece ( plat9um wire is seal$ into ! inside end ( ea* glass tube4 ,! plat9um wires are connect$ to copp] wires lead+ out ( ! l[] ends ( ! tubes4 ,if ! bottle is inv]t$ & fill$ ) a dilute solution ( sulphuric acid1 ! curr5t f two or ?ree dry cells w decompose ! wat]4 ,! batt]y %\ld be connect$ to ! wires runn+ ?r\gh ! glass tubes4 ,bubbles ( gas w rise f ! plat9um wires4 ,oxyg5 gas w rise f ! positive wire or electrode & hydrog5 gas f ! negative electrode4 ,if two te/ tubes are fill$ ) acidulat$ wat] & !n inv]t$ ov] ! wires1 ! tubes w collect ! gas4 ,9 a few m9utes x w be notic$ twice z mu* hydrog5 z oxyg5 has be5 g5]at$4 ,if copp] or brass electrodes re us$ ! acid w attack ! positive "o & a *emical action w take place :i* w prev5t ! lib]ation ( any appreciable am\nt ( oxyg51 unless an excessive am\nt ( curr5t is pass$ ?r\gh4 ,,electroplat+4 ,electroplat+ consi/s ( coat+ bodies ) metal by means ( an electric curr5t4 ,! prop] *emicals1 a small tank & a suitable s\rce ( curr5t are ! only app>atus requir$4 ,! process may be outl9$ z foll[s3 ,?or\ghly clean ! article to be electroplat$ s z to remove all grease & dirt4 ,atta* x to ! negative pole ( ! batt]y & susp5d x 9 an electrolyte compos$ ( "s *emical salt ( ! metal to be deposit$4 ,9 ord] to ma9ta9 ! /r5g? ( ! solution1 a piece ( metal ( ! k9d to be deposit$ is atta*$ to ! positive electrode4 ,a tank = plat+ small articles su* z keys1 r+s1 knives1 etc41 may be made out ( a squ>e glass batt]y j> by provid+ x ) a wood5 m\ld+ fitt$ ar\nd ! top edge to support ! conductor rods4 ,! rods are made ( brass or copp] & are ?read$ at "o end s z to be provid$ ) b9d+ po/s4 ,! c5tre rod is ! "o f :i* ! articles to be plat$ are susp5d$4 ,!y %\ld be atta*$ to x by means ( a ?9 copp] wire4 ,! two outside rods support ! anodes4 ,! anodes are %eets ( metal ( ! k9d to be deposit$ :i*1 9 ! case ( copp] plat+1 w\ld be copp]1 9 a case ( silv] plat+ silv]1 nickel = nickel plat+1 etc4 ,illu/ration3 ,,fig4 #ahf4--;,electroplat+ ,tank4 ,objects :i* are to be plat$ mu/ be free f all traces ( dirt or grease or ! plat+ w n be uni=m because x w n /ick to ! dirty spots4 ,articles made ( pla/]1 wax1 etc41 :i* are n conductors ( electricity c be plat$ by fir/ cov]+ ) p[d]$ graphite4 ,articles ( iron1 /eel1 z9c & t9 _c be silv] or gold plat$ unless fir/ cov]$ ) a ?9 coat+ ( copp]4 ,a s+le /orage cell is an excell5t s\rce ( curr5t = electroplat+4 ,a rheo/at %\ld be plac$ 9 ! circuit s t ! curr5t c be regulat$4 ,! negative pole %\ld be connect$ to ! c5tre rod f :i* ! articles are susp5d$4 ,! positive pole is connect$ to ! rods support+ ! anodes4 ,! tank %\ld be fill$ ) electrolyte to )9 ab\t an in* ( ! top4 ,! articles to be plat$ & also ! anodes %\ld be completely subm]g$4 ,! electrolyte us$ = copp] plat+ is simply a solution ( copp] sulphate 9 wat]4 ,! electrolyte = nickel plat+ is compos$ ( "o "p ( nickel sulphate dissolv$ 9 tw5ty p>ts ( wat] to :i* "o "p ( sodium bisulphate is add$4 ,articles :i* h be5 electroplat$ mu/ be buff$ to give !m a bright poli%4 ,,electric ,,curr5t ,,g5]at$ ,,by ,,heat4 ,if ! po9t ( contact betwe5 two dissimil> metals is heat$1 a curr5t ( electricity w be g5]at$4 ,?is pr9ciple 0 discov]$ ne>ly "o hundr$ ye>s ago by a sci5ti/ nam$ ,seebeck1 & has result$ 9 _m attempts on ! "p ( inv5tors to utilize ! heat ( ! sun's rays 9 produc+ electricity4 ,illu/ration3 ,,fig4 #ahg4--;,g5]at+ ,electric ,curr5t by ,heat4 ,an int]e/+ exp]im5t illu/rat+ ! production ( electricity by heat c be easily p]=m$ ) v simple app>atus4 ,an alcohol lamp1 c&le or s\rce ( heat1 a piece ( copp]1 a /eel ne$le & a galvanomet] or a telephone receiv] are all t are necess>y4 ,! galvanomet] or ! telephone receiv]1 :i*ev] is us$1 is = ! purpose ( detect+ ! electric curr5t4 ,connect ! ne$le & ! piece ( copp]1 :i* %\ld pref]ably be a small %eet1 to ! galvanomet] or telephone receiv]4 ,hold ! copp] %eet ov] ! flame ( ! alcohol lamp until x is q hot & !n t\* ! hotte/ portion ) ! po9t ( ! ne$le4 ,en\gh curr5t w be g5]at$ to produce a click ,9 ! telephone receiv] or to cause ! galvanomet] ne$le to move4 ,! ne$le %\ld be press$ aga9/ ! copp] tightly en\gh s t ! po9t cuts ?r\gh ! scale or oxide on ! surface & makes a good electrical contact ) ! metal und]nea?4 ,v>i\s devices = ! production ( electricity consi/+ ( a l>ge numb] ( /rips ( dissimil> metals 9 contact ) "o ano!r & arrang$ s t !y c be easily heat$ h be5 inv5t$4 ,!y are call$ !rmopiles4 ,a ,,h&y ,,light4 ,figure #ahh %[s a simple & h&y =m ( light :i* utilizes ! curr5t f a home made prim>y cell4 ,x consi/s ( a glass fruit j>1 fitt$ ) a tight wood5 top4 ,a m9iature porcela9 socket & a #a4e volt tung/5 lamp are m\nt$ on top4 ,! batt]y is arrang$ s t ! z9c elem5t c be drawn up out ( ! solution :5 ! light is n 9 use & any wa/e !reby prev5t$4 ,! z9c electrode consi/s ( a /rip ( t metal fa/5$ onto ! l[] end ( a brass rod by means ( two ?read$ nuts4 ,! upp] end ( ! rod passes ?r\gh a small metal coll> on ! top ( ! cov]1 provid$ ) a ?umb-screw s t :5 ! electrode is lift$ up out ( ! solution x may be clamp$ firmly 9 t position4 ,! z9c /rip %\ld n be s long t x w n cle> ! solution :5 rais$ up if ! j> is ab\t half fill$4 ,illu/ration3 ,,fig4 #ahh4--;,a ,h&y ,light4 ,! positive electrode is a batt]y c>bon m\nt$ on ! l[] end ( a brass rod4 ,! brass rod 9 ?is case is n movable because ! c>bon c rema9 9 ! solution indef9itely )\t any wa/e4 ,! jo9t betwe5 ! brass rods & ! electrode %\ld be coat$ ) p>aff9e s t ! *emicals 9 ! solution w n cause any corrosion4 ,! rods %\ld be connect$ to ! lamp socket4 ,:5 ! z9c is l[]$ into ! solution1 ! lamp w be light$ by ! curr5t g5]at$4 ,! electrolyte %\ld be t describ$ z ! bi*romate solution on page #cd ( ,vol4 ,i ( ?is book4 ,,an ,,exp]im5tal ,,arc ,,lamp4 ,an arc lamp is op]at$ by caus+ an electric curr5t to pass betwe5 two c>bon rods4 ,if ! voltage is high en\gh1 c>bon vapor w =m betwe5 ! rods :5 !y are sep>at$ a %ort di/ance4 ,x requires an ,e4 ,m4 ,f4 ( approximately fifty volts to produce & ma9ta9 an arc4 ,a six volt /orage batt]y w heat a pair ( %>p po9t$ c>bons to inc&esc5ce & produce a light some:at simil> to ! electric arc4 ,illu/ration3 ,,fig4 #ahi4--;,exp]im5tal ,arc ,lamp4 ,ord9>y c>bon rods su* z ^? us$ 9 fla%light batt]ies w s]ve v nicely = a batt]y arc lamp4 ,! ends %\ld be fil$ to %>p po9ts4 ,figure #ahi %[s a simple me?od ( m\nt+ ! c>bons4 ,! l[] "o is sold]$ to a piece ( brass /rip by tak+ advantage ( ! brass cap press$ ov] ! upp] end ( fla%light batt]y c>bons4 ,! upp] c>bon is m\nt$ on ! =w>d end ( a brass lev] :i* is pivot$ ne> ! back end s t an adju/able c\nt]weight may be us$ to regulate ! pressure on ! po9t ( contact betwe5 ! two c>bons4 ,if ! c>bons are t\*+ lightly & are connect$ to a /rong batt]y ( six volts or m1 ! po9t ( contact w be heat$ to inc&esc5ce & w produce a dazzl+ :ite light4 ,a real arc lamp = op]ation on ! #aaj volt curr5t1 9 s]ies ) a bank ( lamps1 may be con/ruct$ on ?is same s*eme by us+ l>g] c>bons & elim9at+ ! c\nt]weight4 ,! upp] arm %\ld be pivot$ 9 ! same mann] b %\ld move /iffly s t x w rema9 9 any position 9 :i* x is set4 ,if ! #aaj volt curr5t is us$1 ! c>bons %\ld be br\ght toge!r & !n sep>at$ a %ort di/ance4 ,! curr5t w cont9ue to fl[ across & w =m an arc produc+ a v p[]ful purpli% :ite light4 ,! arc w consume ! c>bons q rapidly & also g5]ate a great deal ( heat4 ,!re=e if x is int5d$ to use ! light = any l5g? ( "t x is advisable to fa/5 ! c>bons by means ( a clamp s t !y may be easily replac$4 ,a ,,magnetic ,,div]4 ,?is is a my/ify+ piece ( app>atus to ^? :o d n "k its secret4 ,! little div] app>5tly travels up & d[n f ! bottom ( a j> full ( wat] to ! surface at a ^w ( comm&4 ,! div] consi/s ( a small glass te/ tube ab\t two in*es long hav+ ! figure ( a man pa9t$ ^u x4 ,! l[] end is clos$ by a v small cork ?r\gh :i* is pu%$ a l>ge iron tack ) ! head on ! outside4 ,! te/ tube conta9s j en\gh wat] to float head up ev5 ) ! surface ( ! wat]4 ,! exact am\nt ( wat] requir$ to j p]mit en\gh buoyancy = ! div] to rise aga9 to ! surface aft] he has be5 to ! top w h to be det]m9$ by c>eful exp]im5t4 ,! j> conta9+ ! div] %\ld be set on a table hav+ a draw] 9 :i* a pair ( p[]ful electromagnets c be plac$ directly "u ! j>4 ,! electro-magnets are connect$ to a /rong batt]y & a swit* locat$ "u ! rug or c>pet & s arrang$ t x may be clos$ by /epp+ on x lightly & )\t attract+ att5tion4 ,if ! div] does n h too mu* b\yancy ! attraction betwe5 ! tack & ! electro-magnets :5 ! swit* is clos$ %\ld be suffici5t to cause him to desc5d to ! bottom ( ! j>4 ,:5 ! curr5t is turn$ (f ! div] %\ld rise aga94 ,illu/ration3 ,,fig4 #aij4--,! ,magnetic ,div]4 ,,! ,,magnetic ,,fi%4 ,! same sort ( a s*eme employ$ 9 ! ,magnetic ,div] may be us$ = produc+ a magnetic fi% :i* w swim ar\nd & ar\nd a pan ( wat]4 ,illu/ration3 ,,fig4 #aia4--,! ,magnetic ,fi%4 ,x consi/s ( a small wood5 fi% hav+ a magnetis$ sew+ ne$le atta*$ to ! "u side4 ,! fi% is plac$ 9 a b[l ( wat] on a table hav+ a draw] 9 :i* a pair ( electro-magnets m\nt$ on a rotat+ wood5 arm may be plac$ s t !y sw+ ar\nd directly und]nea?4 ,a piece ( /rong tw9e wrapp$ ar\nd an empty spool & atta*$ to ! c5tre ( ! arm makes x possible to rotate ! magnets by pull+ on ! /r+4 ,:5 ! magnets are connect$ to a batt]y !y w ex]t a /rong magnetic pull ^u ! ne$le fa/5$ to ! fi% & if sl[ly rotat$ w cause ! latt] to foll[ sl[ly ar\nd ! b[l4 ,a ,,magnetic ,,cl[n4 ,small figures ( m5 or animals cut out ( %eet iron w p]=m _m amus+ acrobatic feats :5 "u ! influ5ce ( a magnet4 ,illu/ration3 ,,fig4 #aib4--,! ,magnetic ,cl[n4 ,su* figures are easily cut out ( an old t9 crack] box ) a pair ( snips or /rong %e>s4 ,a reali/ic appe>ance may be secur$ ) ! aid ( a little pa9t4 ,a t9 cl[n hav+ a %>ply po9t$ hat1 h&s & feet w d all sorts ( /unts :5 hang+ f ! poles ( a horse%oe magnet4 ,if sev]al cl[ns are made !y c be caus$ to hold h&s1 /& on ea* o!rs heads1 jump up 9 ! air1 etc4 ,,an ,,electric ,,breeze4 ,if a sew+ ne$le is connect$ to "o ( ! dis*>ge rods ( a /atic ma*9e & ! po9t ( ! ne$le is pres5t$ to ! flame ( ! c&le :ile ! ma*9e is 9 op]ation1 ! flame w be repell$ j z if a breeze or curr5t ( air 7 issu+ f ! ne$le4 ,?is is caus$ by ! bru% dis*>ge :i* takes place :5ev] high voltage electricity has a *ance to escape f a %>p po9t or edge4 ,! bru% dis*>ge w be mu* m m>k$ if ! cond5s]s or ,leyd5 ,j>s are n connect$ to ! dis*>ge rods4 ,! electric breeze c be felt if ! po9t ( ! ne$le is br\ght ne> to ! side ( ! face4 ,x is necess>y t ! ne$le & ! wire connect+ x to ! /atic ma*9e be v c>efully insulat$ f all surr\nd+ objects :i* might dissipate ! electricity be=e x has an opportunity to escape f ! ne$le po9t4 ,illu/ration3 ,,fig4 #aic4--;,an ,electric ,breeze4 ,a ,,/atic ,,motor4 ,?is is a motor op]at$ by ! electricity f a /atic ma*9e4 ,x does n possess any appreciable am\nt ( p[] & mu/ be v c>efully built & balanc$ 9 ord] to op]ate4 ,x consi/s ( f\r celluloid p+-pong balls1 ,b1 ,b1 ,b1 ,b1 cov]$ ) t9foil & m\nt$ on opposite ends ( two wood5 spokes4 ,! balls %\ld be at "r angles to ea* o!r z %[n 9 ! illu/ration4 ,! spokes pass ?r\gh a cork4 ,! cork is m\nt$ on a wire spoke or knitt+ ne$le pass+ ?r\gh its c5tre & support$ 9 small not*es 9 ! top ( two upright wood5 be>+s4 ,! device mu/ be v c>efully balanc$ s t ! slighte/ impulse w cause x to sp9 & s t !re w n be any dead c5tre4 ,! upright be>+s are m\nt$ on a wood5 base4 ,two o!r t9foil cov]$ balls ,a1 ,a1 are support$ on glass or rubb] insulat+ rods at opposite ends ( ! base on a level ) ! axle & 9 su* a position t ! balls ,b1 ,b1 ,b1 ,b1 almo/ t\* ,a & ,a z !y sw+ pa/4 ,illu/ration3 ,,fig4 #aid4--,! ,/atic ,motor4 ,connect ,a & ,a ea* to "o dis*>g] rod on ! ,wim%ur/ ma*9e4 ,/>t ! ma*9e & give ! axle ( ! /atic motor a twi/4 ,z ! balls ,b1 ,b g pa/ ,a & ,a !y w receive a *>ge ( electricity :i* w cause !m to repel ea* o!r until !y h swung pa/ ! o!r ball on ! opposite side & dis*>ge _! electricity 9 return = a *>ge ( ! opposite sign4 ,any ( ! ,foll[+ ,practical ,books 99w be s5t ,at ,once1 ,po/-paid on receipt ( price499 ,!re is v little dang] ( los+ curr5cy 9 a lett] if ! foll[+ directions are obs]v$3 ,cut a circul> hole ! diamet] ( ! co9 9 a piece ( c>dbo>d1 ( suffici5t size to fit closely 9 ! envelope4 ,! c>dbo>d %\ld be no ?ick] ?an ! co94 ,ins]t ! co9 9 ! hole & pa/e a piece ( pap] on bo? sides ( ! c>dbo>d to prev5t ! co9 f fall+ out4 ,,cole ,,morgan ,publi%]s ( ! ,arts & ,sci5ces ,s]ies ,p4,o4 ,box #dgc ,new ,york1 ,n4 ,y4 99,! ,boy ,electrician99 ,practical ,plans = ,electrical ,toys & ,app>atus1 ) an ,explanation ( ! ,pr9ciples ( ,ev]yday ,electricity4 99,by ,,alfr$ ,p4 ,,morgan499 ,au?or ( ,wireless ,telegraph ,con/ruction = ,amateurs & ,wireless ,telegraphy & ,telephony1 etc4 99,) full-page ,illu/rations & #cbd ,work+ ,draw+s & ,diagrams99 99by ! au?or4 #hvo41 ,clo?1 ,net ,price1 #b4jj499 ,?is is ! age ( electricity4 ,! mo/ fasc9at+ ( all books = a boy mu/ !re=e be "o deal+ ) ! my/]y ( ?is anci5t =ce & mod]n wond]1 ev5 a m]e li/ ( ^: s]vices is impossible4 ,! be/ qualifi$ ( exp]ts to in/ruct boys1 ,alfr$ ,p4 ,morgan1 has 9 a book f> sup]ior to any o!r ( its k9d told n only h[ to make all k9ds ( motors1 telegraphs1 telephones1 batt]ies1 etc41 & to d s economically1 b has expla9$ ! pr9ciples ^u :i* ^! dep5d = op]ation1 & h[ ! same ?+ is done 9 ! e-day _w be well pres5t$ & s attractive is ?is really great book t x w be an education = any bright boy to h x1 z well z ! be/ k9d ( a moral safegu>d1 by leav+ no "t or ?\ght = evil1 & a means ( future b5efit beyond ! p[] ( any "o to reckon4 ,glanc+ ov] ! pages ( ?is book1 "o _c b be impress$ by ! excell5t illu/rations1 cle>ness ( expression & ! l>ge numb] ( subjects t are cov]$4 ,x is beyond d\bt ! be/ book 9 ?is l9e t has ev] be5 writt5 or publi%$4 ,x is a book t w delight e boy :o has a lean+ t[>ds electrical exp]im5ts4 ,! au?or writes 9 a cle> & *atty /yle & :ile he has a ?or\gh te*nical k ( 8 subject he has succe$$ 9 treat+ x 9 a simple mann] s t x is readily intelligible to 8 "y read]s4 99,among ! ,*apt] ,head+s & ,cont5ts are399 ,magnets & ,magnetism--,/atic ,electricity--,/atic ,electric ,ma*9es--,cells & ,batt]ies--,electro-,magnetism & ,magnetic ,induction--,electrical ,units--,electrical ,appurt5ances--,electrical ,measur+ ,in/rum5ts--,bells1 ,al>ms & ,annunciators--,electric ,telegraphs--,microphones & ,telephones--,induction ,coils--,trans=m]s--,wireless ,telegraphy--,wireless ,telephony--,electric ,motors--,dynamos--,an ,electric ,railway--,m9iature ,light+--,miscellane\s ,electrical ,app>atus4 99,,read ,,:at ,,has ,,be5 ,,said ,,( ,,x499 ,ev5 a casual glance ?r\gh ! _m pages ( ! book does n fail to emphasize ! fact t ,mr4 ,alfr$ ,p4 ,morgan has inde$ succe$$ well 9 giv+ ! juv5ile electricians a "w t has long be5 s\ght4--,popul> ,electricity4 ,we h no hesitation 9 comm5d+ ! book to ! att5tion ( ! juv5ile audi5ce = :i* x is int5d$4--,bo/on ,po/4 ,a great book = ent]pris+ boys4 ,bright boys w highly appreciate x & feel l ?ank+ ! wideawake publi%]s = putt+ su* a reliable & int]e/+ "w 9 ! field4--,new ,hav5 ,j\rnal4 ,! book cov]s ! subject ( electricity ?or\ghly 9 all its phases & is a spl5did acquisition to any boy's libr>y4--,detroit ,times4 ,9 ?is age ( electricity a book l ! pres5t "o is bo? fasc9at+ & valuable especially to boys4 ,! book is attractive ) its _m illu/rations & w prove ( mu* educational value = any bright boy4--,zion's ,h]ald4 ,?is is an admirably complete & explicit h&book = "y boys :o fall "u ! spell ( t9k]+ ) electrical app>atus4--,bo/on ,transcript4 ,well pres5t$ & attractive ?is book w be a s\rce ( great b5efit & delight = any bright boy4--,new ,orleans ,times-,picayune4 99,price1 #b4jj1 ,po/paid99 ,,c\ntless ,,o!r ,,magaz9es1 ,,newspap]s ,,& ,,libr>ies ,,h ,,endors$ ,,?is ,,great ,,book4 ,,s5d ,,= ,a ,,copy ,,n[4 99,if y are int]e/$ 9 ?is great book1 write = our #h-page special99 99descriptive circul>499 99,exp]im5tal ,wireless ,con/ruction99 99,,eighty-,,six ,,pages ,,n9ety-,,?ree ,,illu/rations99 99,only #be ,c5ts1 ,po/paid99 ,"h at la/ is ! book :i* e "y exp]im5t] int]e/$ 9 con/ruct+ 8 own wireless app>atus has be5 look+ =4 ,a book :i* tells h[ to build app>atus :i* anyone w\ld be pr\d to own4 ,x is a m advanc$ book ?an ,wireless ,con/ruction & ,in/allation = ,beg9n]s1 & describes app>atus :i* is mu* m elaborate & s5sitive4 ,! in/rum5ts h all be5 ! subject ( consid]able exp]im5tal "w & /udy4 ,all ! app>atus has be5 put to practical te/ & c>efully improv$ by clev] exp]ts4 ,by pur*as+ ?is book y get ! b5efit ( va/ k & exp]i5ce & are enabl$ to build f> bett] in/rum5ts ?an by foll[+ y\r own designs & haphaz>d me?ods4 ,,! ,,trem5d\s ,,popul>ity ,,( ,,?is ,,valuable ,,little ,,book ,,is ,,only ,,an ,,indication ,,( ,,its ,,great ,,wor?4 ,x has only be5 on ! m>ket a %ort "t1 yet ! sales w und\bt$ly soon rea* a po9t :i* w\ld indicate t exp]im5t]s unque/ionably consid]1 t 9 proportion to its size1 x is ! be/ book on ! m>ket4 ,x does n describe any old or obsolete =ms ( wireless app>atus b only ! late/ types ( a]ials1 sp>k coils1 keys1 gaps1 cond5s]s1 helixes1 oscillation trans=m]s1 loose c\pl]s1 tun+ coils1 detectors1 load+ coils1 v>iable cond5s]s1 a]ial swit*es1 etc4 ,,x ,,is ,,"o ,,( ,,! ,,mo/ ,,detail$ ,,& ,,?or\gh ,,books ,,ev] ,,publi%$4 ,! in=mation is all int5sely practical4 ,complete directions & dim5sions are giv54 ,no?+ is left to be guess$ at4 ,! book mu/ really be se5 to be appreciat$4 99,p>tial ,cont5ts99 ,*apt] ,i4--,,! ,,a]ial4 ,! ,location ( ! ,/ation4 ,! ,con/ruction ( an ,op]at+ ,b5*4 ,! ,a]ial & ,gr\nd4 ,! ,supports or ,ma/s4 ,types ( ,a]ials4 ,h[ to ,erect an ,a]ial4 ,protection f ,lightn+1 ,etc4 ,*apt] ,,ii4--,,sp>k ,,coils4 ,! ,con/ruction ( ,sp>k ,coils4 ,a #a_/d-;in* ,sp>k ,coil4 ,a #a_/b-;in* ,sp>k ,coil4 ,a #a-;in* ,sp>k ,coil4 ,a #a #a_/b-;in* ,coil4 ,a #b-;in* ,coil4 ,s\rces ( ,curr5t4 ,dry ,cells4 ,/orage ,cells4 ,wireless ,keys1 ,etc4 ,*apt] ,,iii4--,,transmitt+ ,,app>atus ,,& ,,its ,,con/ruction4 ,/ep-d[n ,trans=m]s4 ,sp>k ,gaps4 ,! ,oscillation ,cond5s]4 ,leyd5 ,j>s4 ,helixes4 ,oscillation ,trans=m]s1 ,etc4 ,*apt] ,,iv4--,,! ,,receiv+ ,,app>atus ,,& ,,its ,,con/ruction4 ,a ,silicon ,detector4 ,a ,gal5a ,detector4 ,! ,d\ble ,slide ,tun+ ,coil4 ,h[ to ,make a ,fix$ ,cond5s]4 ,build+ a ,loose ,c\pl]4 ,! ,load+ ,coil4 ,h[ to ,make a ,v>iable ,cond5s]1 ,etc4 ,*apt] ,v4--,,arrangem5t ,,& ,,op]ation ,,( ,,! ,,app>atus4 ,a]ial ,swit*es4 ,! ,buzz] ,te/4 ,us+ ,m ,?an ,"o ,detector4 ,%unt+ ! ,detector4 ,complete ,outfits4 ,portable ,sets4 ,! ,op]ation ( ! ,/ation1 ,etc4 99,,lessons ,,9 ,,wireless ,,telegraphy99 ,,f\r? ,,edition #gb ,pages #ff ,illu/rations ,a sy/ematic c\rse 9 ! elem5t>y pr9ciples4 ,writt5 s y c und]/& x4 ,9 #ce lessons4 #a4--,magnetism4 #b4--,magnetic ,induction4 #c4--,prim>y & ,second>y ,cells4 #d4--;,electric ,curr5ts4 #e4--;,electromagnetism4 #f4--;,dynamo-,electric ,ma*9]y4 #g4--,! ,induction ,coil4 #h4--,! ,trans=m]4 #i4--,leyd5 ,j>s & ,cond5s]s4 #aj4--;,electromagnetic ,!ory4 #aa4--;,electric ,waves4 #ab4--,pr9ciples ( ,wave ,telegraphy4 #ac4--,! ,a]ial4 #ad4--,! ,wireless ,coil4 #ae4--,! ,high ,pot5tial ,trans=m]4 #af4--,! ,oscillation ,cond5s]4 #ag4--,! ,helix4 #ah4--,sp>k ,gaps4 #ai4--,! ,key4 #bj4--;,a]ial ,swit*es4 #ba4--;,an*or ,gaps4 #bb4--;,detectors4 #bc4--,tun+ ,coils4 #bd4--,loose ,c\pl]s4 #be4--;,fix$ ,cond5s]s4 #bf4--,v>iable ,cond5s]s4 #bg4--,telephone ,receiv]s4 #bh4--;,hot ,wire ,ammet]4 #bi4--,pot5tiomet]4 #cj4--;,dead ,end ,losses & ,swit*es4 #ca4--;,di/ribut$ ,capacity4 #cb4--,p\ls5 ,arc4 #cc4--,receiv+ ,undamp$ ,waves4 #cd4--,! ,audion ,amplifi]4 #ce4--;,hook-,ups4 99,price1 #be ,c5ts1 ,po/paid99 ,if y want to und]/& y\r app>atus & h[ x works1 y w ne$ ?is book--ov] #ae1jjj copies 9 use4 99,price1 #be ,c5ts1 ,po/paid99 99,model ,fly+ ,ma*9es99 99,,h[ ,,to ,,build ,,& ,,fly ,,!m99 ,w prove int]e/+ & valuable4 ,h y ev] built & fl[n a ,model ,rac]8 ,if n1 y h miss$ some?+4 ,price1 #be ,c5ts1 ,po/paid4 ,model ,a]oplan+ is "o ( ! mo/ fasc9at+ & in/ructive ( sports4 ,?\s&s ( "y m5 & boys h =m$ ,model ,a]o ,clubs & organiz$ ,fly+ ,conte/s ?r\gh\t ! c\ntry4 ,,model ,,fly+ ,,ma*9es ( ! ,arts & ,sci5ces s]ies is ! only book giv+ reliable data & in/ructions = ! con/ruction ( practical ,model ,a]oplanes4 ,,if ,,y ,,are ,a ,,beg9n]1 ?is is ! book t y ought to h4 ,x w />t y "r4 ,x tells h[ to build sev5 diff]5t types ( ma*9es1 />t+ ) ! simple/ ,monoplane & f9i%+ ) sev]al ,long ,di/ance ,rac+ ,models4 ,,if ,,y ,,are ,,int]e/$ ,,9 ,,model ,,a]oplan+1 ?is book w prove ! "o y h be5 look+ =4 ,gives valuable ,k9ks4 ,tells h[ to c>ve propell]s1 make w9d]s1 adju/ & fly ma*9es1 etc4 ,fully illu/rat$ ) l>ge size1 detail$ work+ draw+s1 %[+ ! exact size ( ea* "p4 ,twelve full-page plates4 ,pr9t$ on fir/-class pap]4 ,heavy cov] 9 ?ree colors4 ,s5t po/paid by return mail ^u receipt ( #be c5ts4 99,,e ,,model ,,aviator ,,ought ,,to ,,h ,a ,,copy99 99,wireless ,con/ruction & ,in/allation = ,beg9n]s99 ,,sev5ty-,,?ree ,,pages ,,sixty-,,sev5 ,,illu/rations4 7,second ,edition47 ,a ,practical ,h&book giv+ detail$ in/ructions = ! ,con/ruction & ,op]ation ( a ,boy's ,wireless ,outfit4 99,only #be;c4 ,prepaid99 ,an indisp5sible book = ! "y wireless exp]im5t]4 ,x n alone %[s h[ to build ! v>i\s in/rum5ts b describes _! actual work+s & tells h[ to op]ate !m4 99,,e ,,boy ,,is ,,advis$ ,,to99 99,,s5d ,,= ,a ,,copy99 ,writt5 9 a v cle> & simple /yle1 ! book is invaluable to a beg9n]4 ,he w be able ) its aid to con/ruct simple app>atus ( ! late/ & approv$ type4 ,! in/rum5ts describ$ 9 ! book h be5 ! subject ( consid]able exp]im5tal "w & special /udy4 ,!y are model$ along simple l9es s t !y w be easy & inexp5sive to con/ruct1 b at ! same "t comb9e features :i* make !m v s5sitive & capable ( receiv+ or transmitt+ messages great] di/ances ?an "s m complicat$ app>atus4 99,,?is ,,book1 ,,consid]+ ,,its ,,wor?1 ,,is ,a ,,gift ,,at #be;c499 ,!re are no old or obsolete =ms ( wireless app>atus discuss$1 b only ! late/ types ( tun+ coils1 receiv+ trans=m]s1 fix$ cond5s]s1 keys1 sp>k coils1 detectors1 etc4 ,! book is illu/rat$ by num]\s detail$ work+ draw+s giv+ all dim5sions4 ,sev]al full-page views ( ! app>atus enable ! beg9n] to fully compreh5d ! text4 99,,! ,,mo/ ,,?or\gh ,,& ,,complete ,,elem5t>y ,,wireless99 99,,con/ruction ,,book ,,publi%$99 ,! pages on ! con/ruction & in/allation ( a]ials w be f\nd to be ( consid]able help to ! exp]im5t]1 = x is "h t ! mo/ tr\ble is exp]i5c$ by ! beg9n]4 ,! practical & helpful in=mation on ?is subject is alone wor? sev]al times ! co/ ( ! book4 99,,p>tial ,,cont5ts99 ,*apt] ,i4--99,,wireless ,,telegraphy994 ,an int5sely int]e/+ subject2 amateur wireless telegraphy2 ! purpose ( ! a]ial & gr\nd2 ! app>atus us$ to s5d messages2 ! app>atus us$ to receive messages4 ,*apt] ,,ii4--99,,a]ials ,,& ,,gr\nds994 ,:]e to put up ! a]ial2 types ( a]ials2 ! ,t a]ial2 ! ma/s2 ! wire2 insulators2 lead+ 9 ! wires2 ! gr\nd4 ,*apt] ,,iii4--99,,h[ ,,to ,,build ,,& ,,op]ate ,,! ,,simplex ,,d\ble ,,slide ,,receiv+ ,,outfit994 ,! tun+ coil2 ! tube2 ! slid]s2 ! fix$ cond5s]2 ! detector p>ts2 assembl+ ! set2 connect+ ! in/rum5ts2 op]ation4 ,*apt] ,,iv4--99,,h[ ,,to ,,build ,,! ,,simplex ,,loose ,,c\pl]1 ,,detector ,,& ,,cond5s]994 ,! base2 ! prim>y2 ! second>y2 ! pill>2 ! swit*2 ,h[ to make ! ,simplex cat :isk] detector2 ,h[ to make ! ,simplex fix$ cond5s]2 ,h[ to connect ! app>atus2 ,h[ to tune ) ! loose c\pl]2 ,h[ to adju/ ! detector4 ,*apt] ,v4--99,,telephone ,,receiv]s ,,& ,,headb&s499 ,*apt] ,,vi4--99,,h[ ,,to ,,build ,,! ,,simplex ,,sp>k ,,coil499 ,! core2 ! second>y2 ! cond5s]2 ! coil heads2 ! base2 ! int]rupt] p>ts2 ! bridge4 ,*apt] ,,vii4--99,,h[ ,,to ,,make ,,! ,,simplex ,,key994 ,*apt] ,,viii4--99,,h[ ,,to ,,connect ,,& ,,op]ate ,,! ,,app>atus994 ,h[ to connect & op]ate a complete wireless /ation2 ,h[ to op]ate2 ! code1 etc4 99,?ree ,new ,books on ,home ,made99 99,electrical ,app>atus99 ,! ,book y are n[ read+ is only ! fir/ volume ( ,home-made ,electrical ,app>atus4 ,writt5 9 a v cle> & simple /yle1 ! o!r volumes are invaluable to ! "y exp]im5t]4 ,!re are no old or obsolete =ms ( app>atus describ$ b only ! late/ electrical devices1 mak+ !m 99,! ,mo/ ,?or\gh & ,complete ,books =99 99! ,"y ,electrical ,exp]im5t] ,publi%$99 ,! p>tial ,table ( ,cont5ts bel[ only gives a small idea ( ! int]e/+ matt] conta9$ 9 ^! volumes4 ,,volume ,,ii #gb ,pages #ee ,illu/rations ,table ( ,cont5ts ,*apt] ,,vi--,,electrical ,,measur+ ,,in/rum5ts4 ,galvanomet]s1 ,ammet]s1 ,voltmet]s1 etc4 ,*apt] ,,vii--,,curr5t ,,control ,,devices4 ,h[ to ,make a ,pole ,*ang+ ,swit* or ,curr5t ,rev]s]4 ,h[ to ,rev]se ,small ,motors4 ,batt]y ,rheo/ats4 ,*apt] ,,viii--,,h[ ,,to ,,make ,a ,,telegraph ,,key ,,& ,,s\nd]4 ,h[ to ,in/all a ,telegraph ,l9e & ,le>n to ,op]ate4 ,le>n+ ! ,morse ,code4 ,*apt] ,,ix--,,h[ ,,to ,,make ,,& ,,in/all ,a ,,telephone4 ,*apt] ,x--,,m$ical ,,coils ,,& ,,%ock+ ,,coils4 ,*apt] ,,xi--,,! ,,con/ruction ,,( ,,sp>k ,,coils4 ,a "o-qu>t] in* ,coil1 a "o-half in* ,coil1 a "o in* ,coil4 ,exp]im5ts ) ,sp>k ,coils4 ,,volume ,,iii #hj ,pages #gc ,illu/rations ,*apt] ,,xii--,,h[ ,,to ,,make ,a ,,dynamo-,,motor4 ,*apt] ,,xiii--,,h[ ,,to ,,make ,a ,,toy ,,batt]y ,,motor4 ,*apt] ,,xiv--,,h[ ,,to ,,build ,,an ,,electric ,,eng9e4 ,*apt] ,,xv--,,m9iature ,,batt]y ,,lamp ,,light+4 ,*apt] ,,xvi--,,coh]] ,,outfits ,,= ,,wireless ,,telegraphy4 ,*apt] ,,xvii--,,h[ ,,to ,,build ,a ,,tesla ,,high ,,frequ5cy ,,coil4 ,exp]im5ts ) ,high ,frequ5cy ,curr5ts4 ,*apt] ,,xviii--,,an ,,exp]im5tal ,,wireless ,,telephone4 ,*apt] ,,xix--,,miscellane\s ,,app>atus4 ,electrolysis ( ,wat]4 ,electro-,plat+4 ,electricity f ,heat4 ,a ,h&y ,light4 ,an ,exp]im5tal ,arc ,lamp4 ,a ,magnetic ,div]4 ,magnetic ,fi%4 ,a ,magnetic ,cl[n4 ,an ,electric ,breeze4 ,a ,/atic ,motor4 99,price ,po/paid1 #be ,c5ts p] ,volume99 ,all ?ree volumes c be suppli$ b\nd toge!r ) h&some clo? cov] = #a4be po/paid4 99,p>ts & ,mat]ials99 ,= ,build+ ! ,app>atus ,describ$ 9 ?is ,book ,we h receiv$ s _m reque/s f our cu/om]s = in=mation z to :]e !y may obta9 "s ( ! mat]ials requir$ to build ! app>atus describ$ 9 ?is book1 t we h made arrangem5ts to supply same4 ,our bus9ess is ess5tially publi%+1 & we d n int5d to g into ! manufacture (1 or to pu% ! sale ( app>atus or p>ts4 ,kn[+1 h[ev]1 t _m ( our cu/om]s live :]e !y are remote f cities or suitable supply h\ses1 :]e !y might obta9 ! necess>y mat]ials1 we believe t ! value ( our books w be increas$ t5 fold to ! read] if we are 9 a position to furni% p>ts1 etc4 99,m#ejj99 ,complete ,set ( ,p>ts = ,dynamo illu/rat$ 9 ,figure #acb 99#c4ge99 ,%ipp+ ,weight1 #e lbs4 99,m#fca99 ,complete ,set ( ,p>ts = ,tesla ,coil 99#d4ej99 ,%ipp+ ,weight1 #d lbs4 99,m#fca;,a99 ,complet$ ,tesla ,coil 99#f4jj99 ,%ipp+ ,weight1 #aj lbs4 99,m#fca;,b99 ,complete ,tesla ,coil ,outfit1 consi/+ ( ,tesla ,coil1 two-in* ,sp>k ,coil1 ,sp>k ,gap & ,leyd5 ,j>s 99#be4jj99 ,%ipp+ ,weight1 #be lbs4 ,please use li/ numb] :5 ord]+4 ,include po/age to pre-pay mail+ *>ges1 or we w %ip by ,express ,collect4 ,no p>ts suppli$ o!r ?an li/$ above4 ,all prices subject to *ange )\t notice4 ,s5d = late/ price li/4 99,,cole ,,morgan1 ,inc499 ,p4,o4 ,box #dgc1 ,city ,hall ,/a4 ,new ,york1 ,n4 ,y4