,illu/ration3 ,,m>coni ,,wireless ,,telegraph ,,/ation1 ,,clifd51 ,,irel& ,photograph$ at night :ile s5d+ a message across ! ,atlantic4 ,! t]rific snapp+ ( ! electric dis*>ge is he>d by "o /&+ ne> ! /ation1 b no light is se54 ,! /range light giv5 out f ! network ( wires is invisible to ! eye1 b is caught by ! photographic plate4 ,illu/ration3 ,,! ,,same ,,/ation ,,photograph$ ,,by ,,daylight ,,! ,,/ory ,,( ,,great ,,inv5tions ,,by ,,elm] ,,ellswor? ,,burns ,,in/ructor ,,9 ,,physics ,,9 ,,! ,,joseph ,,m$ill ,,high ,,s*ool1 ,,*icago ,,) ,,_m ,,illu/rations ,,h>p] ,,bro!rs ,,publi%]s ,,new ,,york ,,& ,,london ,,mcmx ,copyright1 #aiaj1 by ,,h>p] ,,bro!rs ,publi%$ ,novemb]1 #aiaj4 ,pr9t$ 9 ! ,unit$ ,/ates ( ,am]ica ,,cont5ts ,,*apt] ,i ,,! ,,age ,,( ,,ar*im$es ,ar*im$es ! fir/ great inv5tor4--,! battle ( ,syracuse4--,ar*im$es' pr9ciple4--,inv5tions ( ! anci5t ,greeks ,,*apt] ,,ii ,,! ,,age ,,( ,,galileo ,galileo & ! battle = tru?4--,! p5dulum clock4--,galileo's exp]im5t ) fall+ %ot4--,! telescope4--,galileo's /ruggle4--,torricelli & ! b>omet]4--,otto von ,gu]icke & ! air-pump4--,rob]t ,boyle & ! pressure ( air & /eam4--,pascal & ! hydraulic press4--,newton4--,gravitation4--,colors 9 sunlight ,,*apt] ,,iii ,,! ,,eighte5? ,,c5tury ,james ,watt & ! /eam-eng9e4--,! fir/ /eam-eng9e ) a pi/on4--,newcom5's eng9e4--,watt's eng9e4--,horse-p[] ( an eng9e4--,! ,leyd5 j>4--,conductors & insulators4--,two k9ds ( electric *>ge4--,frankl9's kite exp]im5t4--,! lightn+-rod4--,galvani & ! electric curr5t4--,volta & ! electric batt]y ,,*apt] ,,iv ,,f>aday ,,& ,,! ,,fir/ ,,dynamo ,c\nt ,rum=d4--,c\nt ,rum=d's exp]im5t ) ! cannon4--,davy4--,f>aday's electrical discov]ies4--,o]/$ & electromagnetism4--,ampre4--,arago4--,f> aday's fir/ electric motor4--,an electric curr5t produc$ by a magnet4--,detect+ & measur+ an electric curr5t4--,an electric curr5t produc$ by ! magnetic field ( ano!r curr5t4--,f>aday's dynamo4--,a wond]ful law ( nature ,,*apt] ,v ,,great ,,inv5tions ,,( ,,! ,,n9ete5? ,,c5tury ,electric batt]ies4--,! dry batt]y4--,! /orage batt]y4--,! dynamo4--,siem5s' dynamo4--,! drum armature4--,edison's comp\nd-w\nd dynamo4--,electric p[]4--,! fir/ electric railway4--,electric light+4--,! telegraph4--,duplex telegraphy4--,! telephone4--,! phonograph4--,gas-eng9es4--,! /eam locomotive4--,h[ a locomotive works4--,! turb9e ,,*apt] ,,vi ,,! ,,tw5tie?-,,c5tury ,,outlook ,air-%ips4--,! a]oplane4--,h[ ! ,wright a]oplane is kept afloat4--,subm>9es4--,"s sp9n+ tops t are useful4--,! monorail-c>4--,liquid air & ! greate/ cold4--,! electric furnace & ! greate/ heat4--,! wireless telegraph4--,! wireless telephone4--,wond]s ( ! alt]nat+ curr5t4--,x-rays & radium ,,app5dix ,brief notes on important inv5tions ,,index ,,illu/rations ,,fig4 ,,m>coni ,,wireless-,,telegraph ,,/ation1 ,,clifd51 ,,irel& ,,! ,,same ,,/ation ,,photograph$ ,,by ,,daylight #a--,,! ,,battle ,,( ,,syracuse #b--;,,galileo',s ,,p5dulum ,,clock #c--;,,an ,,air ,,!rmomet] #d--,,torricelli',s ,,exp]im5t #e--;,,gu]icke',s ,,air-,,pump #f--;,,gu]icke',s ,,wat] ,,b>omet] #g--;,a ,,lift-,,pump #h--;,a ,,simple ,,hydraulic ,,press #i--;,,h[ ,,an ,,hydraulic ,,press ,,works #aj--;,,an ,,hydraulic ,,press ,,) ,,belt-,,driv5 ,,pump #aa--,,newton',s ,,exp]im5t ,,) ,,! ,,prism #ab--,,pap9',s ,,eng9e #ac--,,! ,,newcom5 ,,eng9e1 ,,9 ,,repair+ ,,:i* ,,watt ,,0 ,,l$ ,,to ,,8 ,,great ,,discov]ies #ad--;,,cyl9d] ,,( ,,watt',s ,,/eam-,,eng9e #ae--;,a ,,fly-,,ball ,,gov]nor #af--;,a ,,leyd5 ,,j> #ag--;,,frankl9',s ,,kite ,,exp]im5t #ah--,,volta ,,expla9+ ,,8 ,,electric ,,batt]y ,,to ,,napoleon ,,bonap>te #ai--,,! ,,fir/ ,,electric ,,batt]y #bj--;,,c\nt ,,rum=d',s ,,exp]im5t ,,) ,,! ,,cannon1 ,,mak+ ,,wat] ,,boil ,,)\t ,,fire #ba--,,o]/$',s ,,exp]im5t #bb--;,a ,,coil ,,) ,a ,,curr5t ,,fl[+ ,,?r\gh ,,x ,,acts ,,l ,a ,,magnet #bc--;,a ,,b> ,,( ,,s(t ,,iron ,,) ,a ,,curr5t ,,fl[+ ,,ar\nd ,,x ,,becomes ,a ,,magnet #bd--,,two ,,coils ,,) ,,curr5ts ,,fl[+ ,,9 ,,! ,,same ,,direction ,,attract ,,ea* ,,o!r #be--,,two ,,coils ,,) ,,curr5ts ,,fl[+ ,,9 ,,opposite ,,directions ,,repel ,,ea* ,,o!r #bf--;,,arago',s ,,exp]im5t #bg--,,"o ,,pole ,,( ,a ,,magnet ,,sp9s ,,r\nd ,a ,,wire ,,?r\gh ,,:i* ,,an ,,electric ,,curr5t ,,fl[s #bh--,,:5 ,a ,,magnet ,,is ,,?ru/ ,,into ,a ,,coil ,,( ,,wire ,,x ,,causes ,a ,,curr5t ,,to ,,fl[ ,,9 ,,! ,,coil1 ,,b ,,! ,,curr5t ,,fl[s ,,only ,,:ile ,,! ,,magnet ,,is ,,mov+ #bi--;,a ,,coil ,,( ,,wire ,,ar\nd ,a ,,compass-,,ne$le #cj--;,,f>aday',s ,,induction-,,coil #ca--;,,hi/orical ,,app>atus ,,( ,,f>aday ,,9 ,,! ,,royal ,,in/itution #cb--;,,f>aday',s ,,fir/ ,,dynamo #cc--;,,f>aday',s ,,laboratory1 ,,:]e ,,! ,,fir/ ,,dynamo ,,0 ,,made #cd--,,! ,,fir/ ,,trans=m] #ce--,,! ,,magnetic ,,field ,,is ,,! ,,space ,,ar\nd ,a ,,magnet ,,9 ,,:i* ,,x ,,w ,,attract ,,iron #cf--,,magnetic ,,field ,,( ,a ,,horse%oe ,,magnet #cg--;,a ,,daniell ,,cell #ch--;,a ,,gravity ,,cell #ci--,,%[+ ,,:at ,,is ,,9 ,a ,,dry ,,batt]y #dj--;,a ,,/orage ,,batt]y1 ,,%[+ ,,! ,,grids #da--;,a ,,/orage-,,batt]y ,,plate ,,made ,,f ,a ,,%eet ,,( ,,lead #db--,,/urgeon',s ,,electromagnet #dc--;,,an ,,electromagnet ,,) ,,_m ,,turns ,,( ,,insulat$ ,,wire #dd--;,,an ,,electromagnet ,,lift+ ,,twelve ,,tons ,,( ,,iron #de--;,a ,,dynamo ,,) ,,siem5s' ,,armature #df--,,r+ ,,armature #dg--;,,fir/ ,,dynamo ,,pat5t$ ,,9 ,,! ,,unit$ ,,/ates #dh--;,a ,,drum ,,armature1 ,,%[+ ,,h[ ,,an ,,armature ,,( ,,f\r ,,coils ,,is ,,w\nd #di--;,a ,,s]ies-,,w\nd ,,dynamo #ej--;,a ,,%unt-,,w\nd ,,dynamo #ea--;,a ,,comp\nd-,,w\nd ,,dynamo #eb--,,"o ,,( ,,edison',s ,,fir/ ,,dynamos #ec--;,a ,,dynamo ,,m\nt$ ,,on ,,! ,,truck ,,( ,a ,,railway ,,c> #ed--;,,fir/ ,,electric ,,locomotive #ee--;,,fir/ ,,edison ,,electric ,,locomotive #ef--;,,edison',s ,,fir/ ,,pass5g] ,,locomotive #eg--;,,fir/ ,,comm]cial ,,electric ,,railway #eh--;,,edison1 ,,am]ica',s ,,greate/ ,,inv5tor1 ,,at ,,"w ,,9 ,,8 ,,laboratory #ei--;,,edison',s ,,fam\s ,,horse%oe ,,pap]-,,filam5t ,,lamp ,,( #fj--;,,fir/ ,,comm]cial ,,edison ,,electric-,,light+ ,,plant2 ,,in/all$ ,,on ,,! ,,/eam%ip ,,columbia ,,9 ,,may1 #fa--;,a ,,telegraph ,,s\nd] #fb--,,morse',s ,,fir/ ,,telegraph ,,in/rum5t #fc--;,a ,,telegraphic ,,circuit ,,) ,,relay ,,& ,,s\nd] #fd--;,a ,,simple ,,telegraphic ,,circuit #fe--;,,fir/ ,,telegraph ,,in/rum5t ,,us$ ,,= ,,comm]cial ,,"w #ff--;,,h[ ,,two ,,messages ,,are ,,s5t ,,ov] ,,"o ,,wire ,,at ,,! ,,same ,,"t #fg--;,,h[ ,,two ,,messages ,,are ,,s5t ,,ov] ,,"o ,,wire ,,at ,,! ,,same ,,"t4 ,,bridge ,,me?od #fh--;,,fir/ ,,bell ,,telephone ,,receiv] ,,& ,,transmitt] #fi--;,a ,,telephone ,,receiv] #gj--,,two ,,receiv]s ,,us$ ,,z ,a ,,complete ,,telephone #ga--;,,c>bon-,,du/ ,,transmitt] #gb--,,! ,,phonautograph1 ,a ,,=]unn] ,,( ,,! ,,phonograph #gc--;,,edison',s ,,fir/ ,,phonograph ,,& ,a ,,mod]n ,,in/rum5t #gd to--,,! ,,f\r-,,cycle ,,gas-,,eng9e #gh--,,two-,,cycle ,,gas-,,eng9e4 ,,crank ,,& ,,connect+-,,rod ,,are ,,enclos$ ,,) ,,! ,,pi/on #gi--,,seld5 ,,explosion ,,buggy1 ,,=]unn] ,,( ,,! ,,mod]n ,,automobile #hj--,,"s ,,e>ly ,,locomotives #ha--;,,h[ ,a ,,locomotive ,,works #hb--;,,h]o',s ,,eng9e #hc--;,,an ,,und]%ot ,,wat]-,,:eel ,,) ,,curv$ ,,blades #hd--;,,an ,,ov]%ot ,,wat]-,,:eel #he--;,,de ,,laval ,,/eam-,,turb9e #hf--;,a ,,mod]n ,,/eam-,,turb9e ,,) ,,top ,,cas+ ,,rais$ ,,%[+ ,,blades #hg--;,,diagram ,,( ,,turb9e ,,%[n ,,9 ,,fig4 #hh--;,a ,,/eam-,,turb9e ,,t ,,runs ,a ,,dynamo ,,g5]at+ #ad1jjj ,,electrical ,,horse-,,p[] #hi--;,,briti% ,,army ,,air-,,%ip ,,nulli ,,secundus ,,ready ,,= ,,flight #ij--;,,basket1 ,,motor1 ,,& ,,propell] ,,( ,,! ,,briti% ,,army ,,air-,,%ip ,,nulli ,,secundus #ia--;,a ,,zeppel9 ,,air-,,%ip #ib--;,,c\nt ,,zeppel9',s ,,deuts*l&1 ,,! ,,fir/ ,,air-,,%ip ,,9 ,,regul> ,,pass5g] ,,s]vice #ic--,,! ,,baldw9 ,,air-,,%ip ,,us$ ,,9 ,,! ,,unit$ ,,/ates ,,army #id--;,,9 ,,full ,,flight #ie--,,wright ,,air-,,%ip ,,9 ,,flight #if--;,,h[ ,,! ,,wright ,,air-,,%ip ,,is ,,kept ,,afloat #ig--,,! ,,seat ,,& ,,motor ,,( ,,! ,,wright ,,a]oplane #ih--,,! ,,bl,,riot ,,monoplane #ii--,,! ,,plung] #ajj--,u4 ,s4 ,,subm>9e ,,%>k ,,ready ,,= ,a ,,dive #aja--;,,fir/ ,,subm>9e ,,con/ruct$ ,,9 ,,! ,,unit$ ,,/ates4 ,,x ,,w5t ,,to ,,! ,,bottom ,,) ,,sev5 ,,m51 ,,:o ,,7 ,,dr[n$ #ajb--;,,h[ ,,m5 ,,9 ,a ,,subm>9e ,,see ,,:5 ,,"u ,,! ,,wat] #ajc--;,a ,,top ,,t ,,sp9s ,,on ,a ,,/r+ #ajd--;,a ,,c> ,,t ,,runs ,,on ,,"o ,,rail #aje--,,manufactur+ ,,diamonds--,,fir/ ,,op]ation #ajf--,,manufactur+ ,,diamonds--,,second ,,op]ation #ajg--,,manufactur+ ,,diamonds--,,?ird ,,op]ation #ajh--,,m>coni ,,& ,,8 ,,wireless-,,telegraph ,,s5d+ ,,& ,,receiv+ ,,in/rum5ts #aji--;,,diagram ,,( ,,wireless-,,telegraph ,,s5d+ ,,app>atus #aaj--;,,diagram ,,( ,,m>coni ,,wireless-,,telegraph ,,receiv+ ,,app>atus #aaa--,,receiv] ,,( ,,bell',s ,,photophone #aab--;,a ,,gas ,,flame ,,is ,,s5sitive ,,to ,,electric ,,waves #aac--;,,capta9 ,,+]soll ,,on ,,bo>d ,,! ,u4 ,s4 ,,battle-,,%ip ,,connecticut ,,us+ ,,! ,,wireless ,,telephone #aad--;,,inc&esc5t ,,electric ,,lamp ,,light$ ,,?\gh ,,n ,,connect$ ,,to ,,any ,,batt]y ,,or ,,dynamo #aae--;,,an ,,electric ,,dis*>ge ,,at ,a ,,pressure ,,( #ab1jjj1jjj ,,volts1 ,a ,,curr5t ,,( #hjj ,,amp]es ,,9 ,,! ,,second>y ,,coil #aaf--;,,an ,,electric ,,dis*>ge ,,sixty-,,five ,,feet ,,9 ,,l5g? #aag--;,a ,,physician ,,exam9+ ,,! ,,bones ,,( ,,! ,,arm ,,by ,,means ,,( ,x-,,rays #aah--,x-,,ray ,,photograph ,,( ,,! ,,eye #aai--,,photograph ,,made ,,) ,,radium ,,introductory ,,note ,great inv5tions are a nev]-fail+ s\rce ( int]e/ to all ( u1 & p>ticul>ly to ! boy 9 8 te5s4 ,! dynamo1 ! electric motor1 ! telegraph1 ) & )\t wires1 ! telephone1 air-%ips1 & _m o!r inv5tions excite 9 him an int]e/ :i* is deep] ?an m]e curiosity4 ,he wants to "k h[ ^! ?+s "w1 & h[ !y 7 inv5t$4 ,! man is s absorb$ 9 ! pres5t t he c>es little = ! pa/4 ,n s ) ! boy4 ,he c>es = ! hi/ory ( inv5tions1 & 9 ?is he is wis] ?an ! man1 = x is only by a /udy ( its orig9 & gr[? t we c und]/& ! l>g] significance ( a great inv5tion4 ,great inv5tions h _! orig9 9 great discov]ies4 ,! /ory ( great inv5tions1 !re=e1 includes ! /ory ( ! discov]ies out ( :i* !y h aris54 ,! /ories ( ! discov]ies & ! inv5tions are insep>able f ! lives ( ! m5 :o made !m1 & s we mu/ deal ) biography1 :i* 9 itself is ( int]e/ to ! boy4 ,su* a /ory is ! /ory ( physical sci5ce 9 ! s]vice ( humanity4 ,! int]e/ ( ! y\? 9 great inv5tions is unque/ion$4 ,%all we /ifle ?is int]e/ by ov]emphasis ( te*nical detail1 or %all we m9i/] to x z a ?+ vital 9 ! life ( ! y\? ( to-day8 ,a few s5t5ces quot$ f ,g4 ,/anley ,hall w indicate ! au?or's po9t ( view4 ,! y\? is 9 ! humani/ /age4 ,nature is s5tim5t be=e x becomes idea or =mula or utility4 ,! h]oes & hi/ory epo*s ( ea* bran* ( sci5ce add ano!r ne$$ quality to ! /ill s l>gely humani/ic /age4 ,a new discov]y1 besides its te*nical record1 involves ! add$ duty ( concise & lucid popul> /atem5t z a tribute to y\?4 ,! ne$ ( a concise & lucid popul> /atem5t ( ! rise ( ! great inv5tions :i* =m ! mat]ial basis ( our mod]n civilization & all ( :i* are new to ! "y m9d1 has no d\bt be5 ke5ly felt by o!rs z x has be5 by ! au?or4 ,! /ory ( our great inv5tions has be5 told 9 sundry volumes = adult read]s1 b n[h]e has ?is /ory1 alive ) human int]e/1 be5 told 9 a =m suit$ to ! "y4 ,x 0 ! realization ( ?is ne$ gr[+ out ( ye>s ( exp]i5ce 9 tea*+ ^! bran*es t l$ ! au?or to attempt ! task ( writ+ ! /ory4 ,! purpose ( ?is book is to tell 9 simple language h[ our great inv5tions came into be+1 to depict ! life-/ruggles ( ! m5 :o made !m1 &1 9 ! tell+ ( ! /ory1 to expla9 ! work+ ( ! inv5tions 9 a way ! boy c und]/&4 ,! /ories :i* are "h wov5 toge!r pres5t ! great epo*s 9 ! hi/ory ( physics1 & are int5d$ to give to ! "y read] a connect$ view ( ! way 9 :i* our great inv5tions h aris5 out ( sci5tific discov]y on ! "o h&1 & conditions :i* we may call social & economic on ! o!r h&4 ,if ! book %all appeal to "y read]s1 & lead !m to an appreciation ( ! mean+ ( a great inv5tion1 ! au?or w feel t 8 purpose has be5 a*iev$4 ,! au?or is deeply indebt$ to ,dr4 ,*>les ,a4 ,mc,murry & ,pr(4 ,newell ,d4 ,gilb]t1 ( ! ,nor!rn ,ill9ois ,/ate ,normal ,s*ool2 ,pr(s4 ,c4 ,r4 ,mann & ,r4 ,a4 ,millikan1 ( ! ,univ]sity ( ,*icago2 & ,pr(4 ,john ,f4 ,woodhull1 ( ,columbia ,univ]sity1 = read+ ! manuscript & (f]+ valuable sugge/ions4 ,ackn[l$gm5t is fur!r made "h ( valuable aid 9 collect+ mat]ial = illu/rations & lett]-press4 ,su* ackn[l$gm5t is due to ,pr(4 ,a4 ,gray1 ,univ]sity ( ,glasg[2 ,pr(4 ,antonio ,fav>o1 ,royal ,univ]sity ( ,padua2 ,pr(4 ,a4 ,zamm>*i1 ,brescia1 ,italy2 ,mr4 ,nikola ,tesla2 ! ,royal ,in/itution1 ,london2 ,mc,clure's ,magaz9e2 ,! ,te*nical ,_w ,magaz9e2 ,! ,sci5tific ,am]ican2 ! ,ellswor? ,company2 ,commonweal?-,edison ,company2 ,association ( ,edison ,illum9at+ ,companies2 ,electric ,controll] & ,supply ,company2 ,kelley-,koett ,manufactur+ ,company2 ,watson-,/illman ,company2 ,g\ld ,/orage ,batt]y ,company2 ,?ord>son ,electric ,company2 ! ,we/+h\se ,ma*9e ,company2 ,m>coni ,wireless ,telegraph ,company ( ,am]ica1 & ! ,siem5s-,s*uck]t ,w]ke1 ,b]l94 ,! draw+s illu/rat+ ,f>aday's exp]im5ts are f exact reproductions ( ,f>aday's app>atus1 made by ,mr4 ,joseph ,g4 ,bran*1 au?or ( ,conv]sations on ,electricity1 & are reproduc$ by 8 k9d p]mission4 ,e4 ,e4 ,b4 ,,*icago1 ,june1 #aiaj4 ,,! ,,/ory ,,( ,,great ,,inv5tions ,*apt] ,i ,,! ,,age ,,( ,,ar*im$es ,ar*im$es1 ! ,fir/ ,great ,inv5tor ,ar*im$es1 ! fir/ great inv5tor1 liv$ 9 ,syracuse m ?an two ?\s& ye>s ago4 ,syracuse 0 a ,greek city on ! isl& ( ,sicily4 ,! ,k+ ( ,syracuse1 ,hi]o1 took great int]e/ 9 ! discov]ies ( ,ar*im$es4 ,"o day ,ar*im$es said to ,k+ ,hi]o t ) 8 own /r5g? he c\ld move any weight :atev]4 ,he ev5 said t1 if !re 7 ano!r e>? to :i* he c\ld g1 he c\ld move ?is e>? :]ev] he pleas$4 ,! ,k+1 full ( wond]1 begg$ ( him to prove ! tru? ( 8 /atem5t by mov+ "s v heavy weight4 ,:]eupon ,ar*im$es caus$ "o ( ! ,k+'s galleys to be drawn a%ore4 ,?is requir$ _m h&s & mu* labor4 ,hav+ mann$ ! %ip & put on bo>d h] usual load+1 he plac$ himself at a di/ance & easily mov$ ) 8 h& ! end ( a ma*9e :i* consi/$ ( a v>iety ( ropes & pulleys1 draw+ ! %ip ov] ! s& 9 z smoo? & g5tle a mann] z if %e _h be5 "u sail4 ,! ,k+1 q a/oni%$1 prevail$ ) ,ar*im$es to make = him all mann] ( ma*9es :i* c\ld be us$ ei!r = attack or def5ce 9 a siege4 ,! ,battle ( ,syracuse ,dur+ ! life ( ,k+ ,hi]o ,syracuse _h no occasion to use ! w> ma*9es ( ,ar*im$es4 ,! gr&son ( ,k+ ,hi]o1 :o succe$$ to ! ?rone1 0 a tyrant4 ,he attempt$ to ?r[ (f ! sov]eignty ( ,rome & ent]$ into an alliance ) ,c>?age4 ,8 cruelty t[>d 8 own p 0 s great t1 aft] a %ort reign1 he 0 assass9at$4 ,!re 0 an>*y 9 ,syracuse = a "t1 ! ,roman & anti-,roman p>ties /riv+ = supremacy4 ,! anti-,roman p>ty ga9+ possession ( ! city1 ! ,romans1 9 ord] to br+ ,syracuse aga9 into subjection1 prep>$ = an attack by sea & l&4 ,!n x 0 t ,syracuse _h ne$ ( ! w> ma*9es made by ,ar*im$es 7,fig4 #a74 ,illu/ration3 ,,fig4 #a--,,! ,,battle ,,( ,,syracuse ,! city def5d$ by ! inv5tions ( ,ar*im$es4 ,! ,romans came ) a l>ge l& =ce & a fleet4 ,!y 7 sure t )9 five days !y c\ld conqu] ! city4 ,b !re are times :5 "o man ) bra9s is wor? m ?an an army4 ,9 ! battle :i* foll[$1 ,ar*im$es ) 8 inv5tions 0 m ?an a mat* = ! ,romans4 ,! city 0 /rong f ! fact t ! wall on "o side lay along a *a9 ( hills ) ov]hang+ br[s2 on ! o!r side ! wall _h its f\ndation close d[n by ! sea4 ,a fleet ( sixty %ips comm&$ by ,m>cellus bore d[n ^u ! city4 ,! %ips 7 full ( m5 arm$ ) b[s & sl+s & javel9s ) :i* to dislodge ! m5 :o f\ght on ! battlem5ts4 ,eight %ips _h be5 fa/5$ toge!r 9 pairs4 ,^! d\ble vessels 7 r[$ by ! out] o>s ( ea* ( ! pair4 ,on ea* pair ( %ips 0 a ladd] f\r feet wide & ( a height to rea* to ! top ( ! wall4 ,ea* side ( ! ladd] 0 protect$ by a rail+1 & a small ro(-l cov]+1 call$ a p5?\se1 0 fa/5$ to ! upp] end ( ! ladd]4 ,?is cov]+ s]v$ to protect ! soldi]s until !y c\ld rea* ! top ( ! wall4 ,!y ?\ght to br+ ^! d\ble %ips close to %ore1 raise ! ladd]s by ropes & pulleys until !y re/$ aga9/ ! wall1 !n scale ! wall & capture ! city4 ,b ,ar*im$es _h crossb[s ready1 &1 :5 ! %ips 7 /ill at "s di/ance1 he %ot /ones & d>ts at ! enemy1 w\nd+ & greatly annoy+ !m4 ,:5 ^! began to c>ry ov] _! heads1 he us$ small] crossb[s ( %ort] range1 s t /ones & d>ts fell con/antly 9 _! mid/4 ,by ?is means he *eck$ _! advance1 & f9ally ,m>cellus1 9 despair1 0 oblig$ to br+ up 8 %ips "u cov] ( night4 ,b :5 !y _h come close to l&1 & s too ne> to be hit by ! crossb[s1 !y f\nd t ,ar*im$es _h ano!r contrivance ready4 ,he _h pi]c$ ! wall z high z a man's head ) _m loopholes :i* on ! outside 7 ab\t z big z ! palm ( ! h&4 ,inside ! wall he _h /ation$ ar*]s & m5 ) crossb[s to %oot d[n ! m>9es4 ,by ^! means he n only baffl$ ! enemy1 b kill$ ! great] numb] ( !m4 ,:5 !y tri$ to use _! ladd]s1 !y discov]$ t he _h cranes ready all along ! walls1 n visible at o!r times b :i* sudd5ly re>$ !mselves above ! wall f ! inside & /ret*$ _! beams f> ov] ! battlem5ts1 "s ( !m c>ry+ /ones weigh+ ab\t five hundr$ p\nds1 & o!rs great masses ( lead4 ,s1 :5ev] ! %ips came ne>1 ^! beams swung r\nd on _! pivots & by means ( a rope runn+ ?r\gh a pulley dropp$ ! /ones ^u ! %ips4 ,! result 0 t !y n only sma%$ ! %ips to pieces1 b kill$ _m ( ! soldi]s on bo>d4 ,ano!r ma*9e made by ,ar*im$es 0 an iron h& or grappl+-hook swung on a *a9 & c>ri$ by a crane4 ,! hook 0 dropp$ on ! pr[ ( a %ip1 & :5 x _h tak5 hold ! %ip 0 lift$ until x /ood on its /]n1 !n quickly dropp$1 caus+ x ei!r to s9k or %ip a great quantity ( wat]4 ,) su* ma*9es1 unkn[n be=e1 ,ar*im$es drove back ! enemy4 ,on ! l&w>d side simil> ma*9es 7 us$4 ,! ,romans 7 r$uc$ to su* a /ate ( t]ror t if !y saw b a rope or a /ick put ov] ! walls !y cri$ out t ,ar*im$es 0 levell+ "s ma*9e at !m & turn$ _! backs & fl$4 ,aft] a long siege1 h[ev]1 hung] =c$ ! ,syracusans to surr5d]4 ,m>cellus s admir$ ! g5ius ( ,ar*im$es t he gave ord]s t he %\ld n be injur$4 ,yet1 9 ! sack ( ! city :i* foll[$1 ,ar*im$es 0 sla9 by a ,roman soldi]4 ,! ,roman hi/orian ,livy records t ,ar*im$es1 :ile int5t on "s figures :i* he _h made 9 ! du/1 al?\gh ! confusion 0 z great z c\ld possibly be1 0 put to dea? by a soldi] :o did n "k :o he 02 t ,m>cellus 0 greatly griev$ at ?is1 & t pa9s 7 tak5 ab\t 8 fun]al1 :ile 8 relations also 7 c>efully s\ght & receiv$ honor & protection on acc\nt ( 8 "n & memory4 ,ar*im$es' ,pr9ciple ,hi]o1 :5 he became ,k+ ( ,syracuse1 decre$ t a cr[n ( gold1 ( great value1 %\ld be plac$ 9 a c]ta9 temple z an (f]+ to ! gods1 & s5t to a manufactur] ! correct weight ( gold4 ,9 due "t ! cr[n 0 br\ght to ! ,k+1 & a beautiful piece ( "w x 04 ,! weight ( ! cr[n 0 ! same z t ( ! gold1 b a report 0 circulat$ t "s ( ! gold _h be5 tak5 out & silv] suppli$ 9 its place4 ,hi]o 0 angry1 b knew no me?od by :i* ! !ft might be detect$4 ,he !re=e reque/$ ,ar*im$es to give ! matt] 8 att5tion4 ,:ile try+ to solve ?is problem ,ar*im$es w5t "o day to a ba?4 ,z he got into ! ba?-tub he saw t z 8 body became imm]s$ ! wat] ran out ( ! tub4 ,he quickly saw h[ he c\ld solve ! problem1 leap$ out ( ! ba? 9 joy1 &1 runn+ home nak$1 cri$ out ) a l\d voice ,eureka6 eureka6 7,i h f\nd x6 ,i h f\nd x67 ,us+ a piece ( gold & a piece ( silv]1 ea* equal 9 weight to ! cr[n1 & a l>ge vase full ( wat]1 he prov$ t ! cr[n 0 n pure gold1 & f\nd h[ mu* silv] _h be5 mix$ ) ! gold4 ,! incid5t ( ! gold5 cr[n may h be5 ! />t+-po9t ( ,ar*im$es' /udy ( solid bodies :5 imm]s$ 9 fluids4 ,e "o kn[s t a boy c lift a heavy /one "u wat] t he c\ld n lift out ( wat]4 ,! /one seems light] :5 9 ! wat]4 ,a div] ) 8 lead-sol$ %oes c\ld sc>cely walk on l&1 b walks easily "u wat]4 ,:5 ! div] comes up1 ! place :]e he 0 imm$iately becomes fill$ ) wat]4 ,n[1 :atev] t wat] weighs :i* fills ! div]'s place1 j t mu* weight w ! div] lose :5 he goes d[n4 ,:at is true ( ! div] is true ( ! /one or ( any object "u wat]4 ,! /one :5 9 ! wat] loses j z mu* weight z ! weight ( ! wat] t w\ld fill its place4 ,?is is ! fact :i* 0 discov]$ by ,ar*im$es & :i* is call$ ,ar*im$es' ,pr9ciple4 ,x is said by an anci5t au?or t ,ar*im$es inv5t$ m ?an =ty ma*9es4 ,( ^! ! be/ kn[n are ! block & tackle1 ! endless screw 7worm ge>71 & ! wat] snail1 or ,ar*im$ean screw4 ,yet 8 delight 0 n 9 8 ma*9es1 b 9 8 ma!matics4 ,?\gh he _h inv5t$ ma*9es to please 8 k+1 he reg>d$ su* "w z trifl+1 & took little int]e/ 9 ! common ne$s ( life4 ,inv5tions ( ! ,anci5t ,greeks ,! common ne$s ( life are to-day ! *ief conc]n ( ! greate/ m51 & s we f9d x h>d to sympa?ize ) ?is view ( ,ar*im$es4 ,8 view1 h[ev]1 0 t ( o!r le>n$ m5 ( 8 "t1 t ! common ne$s ( life are b5ea? ! dignity ( ! s*ol>1 & s we c see :y ! ,greeks made s few great inv5tions4 ,h]o1 :o liv$ a c5tury lat] ?an ,ar*im$es1 inv5t$ a /eam-eng9e1 :i*1 h[ev]1 0 only a toy4 ,a wat]-clock1 9 :i* ! fir/ cog-:eels 7 us$1 0 inv5t$ by ano!r ,greek nam$ ,ktesibus1 :o also inv5t$ ! =ce-pump4 ,! suction-pump 0 kn[n 9 ! "t ( ,ari/otle1 :o liv$ ab\t a c5tury be=e ! "t ( ,ar*im$es1 b ! inv5tor is unkn[n4 ,conc]n+ electricity1 ! ,greeks knew v little4 ,!y knew t amb] :5 rubb$ w attract light objects1 su* z du/ or *aff4 ,amb] 0 call$ by ! ,greeks electron1 because x reflect$ ! brightness ( ! sunlight1 & _! "n = ! sun 0 ,elector4 ,f ! ,greek "n = amb] we get our ^w electricity4 ,! ,greeks possess$ sc>cely m k ( magnets ?an ( electricity4 ,9 fact1 _! ideas ( magnets _c be call$ k1 = !y consi/$ *iefly ( leg5ds4 ,!y told ( ! %eph]d ,magnes1 :o1 :ile wat*+ 8 flock on ,m\nt ,ida1 sudd5ly f\nd ! iron f]rule ( 8 /aff & ! nails ( 8 %oes adh]+ to a /one2 t1 lat]1 ?is /one 0 call$1 aft] him1 ! ,magnes /one1 or ,magnet4 ,!y told impossible /ories ( iron /atues be+ susp5d$ 9 ! air by means ( magnets1 & ( %ips sail+ ne> ! magnetic m\nta9s :5 e nail & piece ( iron 9 ! %ip w\ld fly to ! m\nta91 leav+ ! %ip a wreck ^u ! waves4 ,*apt] ,,ii ,,! ,,age ,,( ,,galileo ,galileo & ! ,battle = ,tru? ,= eighte5 c5turies aft] ! "t ( ,ar*im$es no inv5tions ( importance 7 made4 ,m5 s\ght = tru? :]e tru? c\ld n be f\nd4 ,!y look$ )9 _! m\ldy manuscripts & ask$1 ,:at d ! great philosoph]s say ought to happ58 in/ead ( look+ at nature & ask+1 ,:at does happ58 ,& :5 a man arose :o d>$ to d\bt ! au?ority ( ! old ma/]s & turn to nature to f9d out ! tru?1 all ! weapons at ! comm& ( ! old s*ool 7 hurl$ aga9/ him4 ,let u1 at ?is di/ance1 blame nei!r ! "o side nor ! o!r4 ,! conflict 0 inevitable4 ,x 0 an accid5t ( hi/ory t ! brunt ( ! attack fell ^u a man born 9 ,italy 9 #aefd1 & t ! battle 0 f\ght *iefly 9 ! ,et]nal ,city1 f :i* c5turies be=e _h m>*$ ! legions t conqu]$ ! _w4 ,! boy1 ,galileo1 :o 0 to become ! c5tral figure ( ! great conflict1 0 tal5t$ 9 _m ways4 ,9 lute-play+ 8 skill excell$ t ( 8 fa!r1 :o 0 "o ( ! not$ musicians ( 8 day4 ,8 skill 9 draw+ 0 su* t not$ arti/s submitt$ _! "w to him = criticism4 ,he wrote essays on ! works ( ,dante & o!r classical writ]s4 ,he amus$ 8 boy companions by con/ruct+ toy ma*9es :i*1 ?\gh +5i\s1 did n always "w4 ,8 pref]5ce 0 = me*anics1 b1 z ?is subject (f]$ little prospect ( pr(itable "w1 he took up ! /udy ( m$ic9e 9 accordance ) 8 fa!r's wi%es4 ,9 8 eighte5? ye> he ent]$ ! ,univ]sity ( ,pisa4 ,"h he f\nd m5 :o refus$ to ?9k = !mselves1 b decid$ e "q by ref]r+ to :at ! anci5t philosoph]s said4 ,galileo c\ld n endure su* slavi% submission to au?ority4 ,s /rongly did he ass]t himself t he 0 nicknam$ ,! ,wrangl]1 &1 by 8 wrangl+1 he lo/ a s*ol>%ip 9 ! univ]sity4 ,he neglect$ 8 m$ical /udies & secretly /udi$ ma!matics4 ,8 fa!r1 le>n+ ( ?is1 cons5t$ to 8 becom+ a ma!matician4 ,?us he foll[$ 8 b5t1 ?\gh x seem$ to lead directly to pov]ty4 ,! ,p5dulum ,clock ,x 0 :ile a /ud5t at ! ,univ]sity ( ,pisa t he discov]$ a law ( p5dulums :i* makes possible our p5dulum clocks4 ,:ile at 8 devotions 9 ! ca!dral1 he obs]v$ ! sw++ ( ! bronze lamp :i* _h be5 drawn back = light+4 ,tim+ its sw++ by means ( 8 pulse1 ! only timepiece 9 8 possession1 he f\nd t ! "t ( "o sw+ rema9$ ! same1 ?\gh ! l5g? ( ! sw+ grew small] & small]4 ,?is discov]y l$ to 8 inv5tion ( an in/rum5t = physicians' use 9 tim+ ! pulse4 ,ab\t fifty ye>s lat] he inv5t$ ! p5dulum clock 7,fig4 #b74 ,illu/ration3 ,,fig4 #b--;,,galileo',s ,,p5dulum ,,clock ,x _h only "o h&1 :i* is n %[n 9 ! picture4 ,lack ( funds compell$ him to leave ! univ]sity )\t complet+ 8 c\rse4 ,he return$ to ! p>5tal ro( & cont9u$ 8 sci5tific /udies4 ,! writ+s ( ,ar*im$es 7 8 favorite /udy4 ,) ,ar*im$es' fam\s exp]im5t on ,k+ ,hi]o's cr[n z a />t+-po9t1 he discov]$ ! laws ( float+ bodies1 :i* expla9 :y a %ip or o!r object floats on wat]1 & inv5t$ a balance = weigh+ objects 9 wat]4 ,b su* employm5t won no?+ m sub/antial ?an honor & fame4 ,food & clo?+ 7 ne$$4 ,= two ye>s he /rove )\t success to secure employm5t4 ,at ! end ( t "t he 0 appo9t$ pr(essor ( ma!matics 9 ! ,univ]sity ( ,pisa at ! magnific5t sal>y ( sixty scudi 7ab\t sixty-?ree doll>s7 p] ye>4 ,b any port 9 a /orm2 & 9 ,galileo's ne$y circum/ances ev5 ?is wret*$ sal>y 0 n to be reject$4 ,moreov]1 he c\ld add some:at to 8 income by private tutor+4 ,galileo's ,exp]im5t ) ,fall+ ,%ot ,:ile tea*+ at ! ,univ]sity ( ,pisa1 he p]=m$ 8 fam\s exp]im5t ( dropp+ f ! top ( ! lean+ t[] two %ot1 "o weigh+ t5 p\nds1 ! o!r "o p\nd4 ,n[1 accord+ to ,ari/otle1 ! t5-p\nd %ot %\ld fall 9 "o-t5? ! "t requir$ by ! "o-p\nd %ot4 ,b ! assembl$ company ( pr(essors & /ud5ts saw ! two %ot />t toge!r1 fall toge!r1 & /rike ! gr\nd at ! same in/ant1 & /ill refus$ to believe _! own eyes4 ,!y cont9u$ to affirm t a weight ( t5 p\nds w\ld rea* ! gr\nd 9 a t5? ( ! "t tak5 by a "o-p\nd weight1 because !y 7 able to quote *apt] & v]se 9 :i* ,ari/otle assur$ !m t su* is ! fact4 ,?us ,galileo made enemies ( ! o!r pr(essors1 b = a "t !y c\ld d no?+ m ?an annoy him4 ,ab\t ?is "t ,galileo incurr$ ! wra? ( ! ,gr& ,duke ( ,tuscany1 f :om he _h receiv$ 8 appo9tm5t4 ,he 0 commission$ to exam9e a ma*9e inv5t$ by a nephew ( ! ,gr& ,duke = ! purpose ( clean+ h>bors4 ,galileo pla9ly said t ! ma*9e 0 wor?less4 ,x 0 tri$1 & 8 op9ion prov$ true4 ,b l ! k+s ( old5 "t :o kill$ ! be>] ( evil tid+s ev5 ?\gh ! tid+s 7 true1 8 enemies made 8 position s unpleasant t he resign$4 ,he _h nei!r employm5t nor money4 ,8 fa!r's dea? occurr+ ab\t ?is "t1 ?rew ^u him ! c>e ( a "m1 a wor?less bro!r1 & two si/]s4 ,9 8 di/ress he s\ght help f a fri5d1 & secur$ an appo9tm5t z pr(essor ( ma!matics 9 ! ,univ]sity ( ,padua4 ,8 sal>y 0 "o hundr$ & eighty flor9s 7ab\t n9ety-five doll>s71 :ile o!r pr(essors receiv$ m ?an t5 times z mu*4 ,:ile at ,padua1 ,galileo 0 busy inv5t+4 ,he inv5t$ ! sector1 :i* is to be f\nd 9 mo/ cases ( ma!matical in/rum5ts & is us$ 9 c]ta9 k9ds ( draw+4 ,he also inv5t$ an air !rmomet] 7,fig4 #c71 ! fir/ in/rum5t = measur+ temp]ature4 ,illu/ration3 ,,fig4 #c--;,,an ,,air ,,!rmomet] ,:5 ! air 9 ! bulb gr[s cool] x contracts1 & ! air outside =ces ! ,wat] up ! tube4 ,:5 ! air 9 ! bulb gr[s w>m] x exp&s & =ces ! wat] d[n 9 ! tube4 ,9 #afjd !re appe>$ a new /> ( great brilliancy4 ,x cont9u$ to %9e ) v>y+ brightness = eighte5 mon?s1 & !n vani%$4 ,?is 0 a /range ev5t1 & ,galileo made use ( x4 ,he prov$ t ! new /> mu/ lie among ! mo/ di/ant ( ! heav5ly bodies1 & ?is fact did n agree ) ,ari/otle's view t ! heav5s are p]fect1 & !re=e nev] *ange4 ,a heat$ controv]sy foll[$1 & ,galileo came out boldly 9 favor ( ! !ory t ! e>? revolves ab\t ! sun1 ! prevail+ notion !n be+ t ! e>? does n move1 b t ! sun & o!r heav5ly bodies revolve ar\nd x4 ,! ,telescope ,9 #afji ,galileo le>n$ ( a discov]y t 0 to be ( great value to ! _w1 b a s\rce ( untold tr\ble to himself4 ,an appr5tice ( a ,dut* optician1 :ile play+ ) spectacle l5ses1 *anc$ to obs]ve t if two ( ! l5ses 7 plac$ 9 a c]ta9 position objects se5 ?r\gh !m appe>$ mu* ne>]4 ,galileo1 le>n+ ( ?is1 set to "w to con/ruct a spy-glass1 apply+ 8 k ( light4 ,9 "o day he _h con/ruct$ su* an in/rum5t1 9 :i* he us$ two l5ses l ! l5ses ( ! mod]n op]a-glass4 ,?us1 :ile ! ,dut*man's discov]y 0 by accid5t1 ,galileo's 0 by reason+1 & 0 ! m fruitful1 z we %all see4 ,galileo cont9u$ improv+ 8 telescope until he _h made "o :i* w\ld magnify ?irty times4 ,he 0 ! fir/ to apply ! telescope to ! /udy ( ! heav5ly bodies4 ,! mo/ />tl+ ( 8 discov]ies 0 t ( ! moons ( ! planet ,jupit]1 :i* he call$ new planets4 ,?is ar\s$ ! fury ( 8 enemies1 :o ridicul$ ! idea ( !re be+ new planets2 =1 !y said1 to see ^! planets !y mu/ fir/ be put inside ! telescope4 ,! excitem5t 0 int5se4 ,poets *ant$ ! praise ( ,galileo4 ,a public fte 0 held 9 8 honor4 ,"o ( 8 pupils 0 imprison$ 9 ! t[] ( ,san ,m>co1 :]e he _h gone to make obs]vations ) 8 telescope1 & c\ld n escape until ! cr[d _h satisfi$ _! curiosity4 ,"s ( ! philosoph]s refus$ to look le/ !y %\ld see & be conv9c$4 ,galileo's ,/ruggle ,8 enemies s\ght to /eal f him ! honor ( 8 discov]ies4 ,"s claim$ to h made ! discov]ies be=e ,galileo did4 ,o!rs claim$ t 8 discov]ies 7 false1 t _! only use 0 to gratify ,galileo's vanity & ?ir/ = gold4 ,9 ^! try+ times ! fri5d%ip ( ! great a/ronom] ,kepl] w>d$ (f "s ( ! mo/ exasp]at+ attacks4 ,galileo's fame spread ?r\gh\t ,europe4 ,/ud5ts came 9 great numb]s1 s t he _h little leisure left = 8 own /udies4 ,he !re=e decid$ to leave ,padua1 & secur$ an appo9tm5t z ma!matician & philosoph] to ! ,gr& ,duke ( ,tuscany4 ,?is appo9tm5t took him to ,flor5ce4 ,x 0 "h t an incid5t occurr$ t m>k$ ! beg9n+ ( a p]secution :i* cont9u$ to ! end ( 8 life4 ,z we read ! /ory ( ?is conflict let u rememb] t x 0 n prim>ily a conflict betwe5 ! ,roman ,ca?olic ,*ur* & ,galileo4 ,x 0 a conflict ( pr9ciples4 ,on ! "o side 7 array$ ^? :o said t m5 %\ld always believe z ! anci5t writ]s did2 on ! o!r1 ^? :o said m5 %\ld ?9k = !mselves4 ,9 ! fir/ p>ty 7 mo/ ( ! univ]sity pr(essors & o!rs :o dread$ ! introduction ( new beliefs1 :e!r 9 religion or sci5ce4 ,9 ! second p>ty 7 ,galileo & a small b& ( devot$ foll[]s4 ,at a d9n] at ! table ( ! ,gr& ,duke 9 ,pisa ! conv]sation turn$ on ! moons ( ,jupit]4 ,"s prais$ ,galileo4 ,o!rs condemn$ him1 say+ t ! ,holy ,scriptures 7 oppos$ to 8 !ory ( ! motion ( ! e>?4 ,a fri5d report$ ! incid5t to ,galileo1 & he repli$ to ! argum5ts ( 8 oppon5ts 9 a lett] :i* 0 made public4 ,no d\bt ! /+ ( 8 s>casm made 8 enemies m bitt]4 ,he admitt$ t ! ,scriptures _c lie or err1 b ?is1 he said1 does n hold good ( ^? :o attempt to expla9 ! ,scriptures4 ,9 ano!r lett]1 he quot$ ) approval a say+ ( ,c>d9al ,b>onius1 ,! ,holy ,_s int5d$ to tea* u 9 ! ,bible h[ to g to ,heav51 n h[ ! heav5s g4 ,! fir/ %ot _h be5 fir$4 ,! battle 0 on1 & ! ,*ur*1 because x possess$ ! mo/ p[]ful weapons ( attack1 0 us$ by ! comb9$ =ces to break ! p[] ( ,galileo's reason+4 ,he w5t to ,rome to make 8 def5ce1 b 0 comm&$ by ! ,holy ,(fice n to hold or tea* t ! sun is immovable1 & t ! e>? moves ab\t ! sun4 ,dur+ ano!r visit to ,rome !re 0 %[n to ,galileo an in/rum5t :i*1 x 0 said1 w\ld %[ a flea z l>ge z a cricket4 ,galileo recall$ t "s ye>s be=e he _h s arrang$ a telescope t he _h se5 flies :i* he said look$ z big z a lamb1 & 7 cov]$ all ov] ) hair4 ,?is 0 ! fir/ microscope4 ,galileo quickly improv$ ! in/rum5t1 & soon 8 microscopes 7 9 great dem&4 ,9 violation ( ! decree ( ! ,*ur*1 to :i* he _h submitt$1 he publi%$ 8 mo/ fam\s "w 9 :i* he def5d$ ! !ory t ! e>? moves ab\t ! sun4 ,! book 0 ! outcome ( 8 life-"w1 b ! ,*ur* believ$ x dang]\s4 ,he 0 summon$ to ,rome4 ,conf9$ to a sick-b$1 he plead$ = delay1 :i* 0 grant$4 ,be=e he recov]$1 h[ev]1 ! summons 0 made imp]ative4 ,he mu/ g to ,rome1 or be c>ri$ 9 irons4 ,he w5t 9 a litt]1 c>ri$ by s]vants ( ! ,gr& ,duke4 ,9 ,rome he 0 to appe> be=e ! ,inquisition4 ,!re he 0 treat$ ) a consid]ation nev] be=e accord$ to a prison] ( ! ,inquisition4 ,nor 0 he subject$ to torture1 z has be5 /at$ by "s4 ,he 0 f\nd guilty ( tea*+ ! doctr9e t ! sun does n move1 & t ! e>? moves ab\t ! sun4 ,he 0 compell$ to recant1 & s5t5c$ to ! prison ( ! ,holy ,(fice &1 by way ( p5ance1 to repeat once a week = ?ree ye>s ! sev5 p5it5tial ,psalms4 ,he yield$ )\t res]ve to ! decree ( ! ,inquisition1 r5\nc$ 8 errors & h]esies1 &1 ) 8 h& on ! ,bible1 took oa? nev] aga9 to tea* ! =bidd5 doctr9e4 ,& n[1 ?\gh a %att]$ old man ( sev5ty-f\r1 enjo9$ to sil5ce on ! *ief results ( 8 life-"w1 no?+ c\ld qu5* 8 devotion to sci5ce4 ,9 ^! la/ ye>s1 he publi%$ a new book :i*1 ) 8 e>li] "w1 entitles him to be reg>d$ z ! f\nd] ( ! sci5ce ( me*anics4 ,9 8 /udy ( ma*9es ,galileo f\nd t no ma*9e w d "w ( itself4 ,:5ev] a ma*9e is at "w1 a man or a horse1 or "s o!r p[]1 is at "w ^u ! ma*9e4 ,9 no case w a ma*9e d "w )\t receiv+ an equal am\nt ( "w4 ,torricelli & ! ,b>omet] ,galileo _h a pump :i* he f\nd w\ld n "w :5 ! wat] 0 ?irty-five feet bel[ ! valve4 ,he ?\ght ! pump 0 injur$1 & s5t = ! mak]4 ,! mak] assur$ him t no pump w\ld d bett]4 ,?is l$ ,torricelli1 "o ( ,galileo's pupils1 to ! discov]y ( ! b>omet]4 ,m5 _h said t wat] rises 9 a pump because nature abhors a vacuum4 ,torricelli believ$ t air-pressure & n nature's horror ( a vacuum is ! cause ( wat] ris+ 9 a pump4 ,he inv5t$ ! b>omet] to measure air-pressure4 ,! fir/ b>omet] 0 a glass tube fill$ ) quick-silv] or m]cury 7,fig4 #d74 ,! tube 0 clos$ at ! upp] end1 & ! l[] end1 :i* 0 op51 dipp$ 9 a di% ( m]cury4 ,he all[$ ! tube to /&1 & saw t ! height ( ! m]cury *ang$4 ,?is he believ$ 0 because ! air-pressure *ang$4 ,w9d1 ,torricelli said1 is caus$ by a diff]5ce ( air-pressure1 :i* is due to unequal heat+ ( ! air4 ,= ?is reason a cool breeze bl[s f ! m\nta9 top to ! heat$ valley1 or f sea to l& on a summ] day4 ,illu/ration3 ,,fig4 #d--,,torricelli',s ,,exp]im5t ,otto ,von ,gu]icke & ! ,air-,pump ,ab\t ?is "t a ,g]man burgoma/]1 ,otto von ,gu]icke1 ( ,magdeburg1 0 p]=m+ exp]im5ts on air-pressure4 ,! ,?irty ,ye>s' ,w> _h be5 rag+ = ?irte5 ye>s4 ,! ,sw$i% ,k+1 ,gu/avus ,adolphus1 _h l&$ 9 ,g]many1 & 0 w9n+ victory aft] victory ov] ! imp]ial troops4 ,magdeburg _h ent]$ into an alliance ) ! ,sw$i% ,k+1 by :i* he 0 grant$ free passage ?r\gh ! city1 :ile1 on ! o!r h&1 he promis$ protection to ! city4 ,! imp]ial army "u ,tilly & ,papp5heim laid siege to ! city4 ,on ! "o side !re 0 hope t ,gu/avus w\ld arrive 9 "t to effect a rescue2 on ! o!r1 a det]m9ation to conqu] be=e su* aid c\ld arrive4 ,:ile ,gu/avus 0 on 8 way to ! rescue1 ,magdeburg 0 tak5 by /orm1 & ! mo/ horrible sc5e ( ! ,?irty ,ye>s' ,w> 0 enact$4 ,tilly gave up ! city to plund]1 & 8 soldi]s )\t m]cy kill$ m51 wom51 & *ildr54 ,9 ! mid/ ( ! sc5e ( c>nage ! city 0 set on fire1 & soon ! horrors ( fire 7 add$ to ! horrors ( ! sword4 ,9 less ?an twelve h\rs tw5ty ?\s& p p]i%$4 ,gu]icke's h\se & family 7 sav$1 b ! suff]+s ( ! city 7 n yet end$4 ,9 five ye>s ! enemy 0 aga9 be=e ! walls1 & ,magdeburg1 !n 9 ! possession ( ! ,sw$es1 0 compell$ to yield to ! comb9$ ,saxon & imp]ial troops4 ,gu]icke ent]$ ! s]vice ( ,saxony1 & 0 aga9 made mayor ( ! city4 ,9 ! mid/ ( ^! sc5es ( w>1 he f\nd "t to cont9ue 8 /udies4 ,he made ! fir/ air-pump1 & ) x p]=m$ exp]im5ts :i* l$ to "s v important results4 ,! exp]im5ts :i* ,gu]icke made ) 8 air-pump ar\s$ ! att5tion ( ! pr9ces1 & especially ,emp]or ,f]d9&4 ,gu]icke 0 call$ to p]=m 8 exp]im5ts be=e ! ,emp]or4 ,! mo/ /rik+ ( ^! exp]im5ts he p]=m$ ) two holl[ copp] hemisph]es ab\t a foot 9 diamet]1 fitt$ closely toge!r4 ,:5 ! air 0 pump$ out1 sixte5 horses 7 b>ely able to pull ! hemisph]es ap>t1 ?\gh1 :5 air 0 admitt$1 !y fell ap>t ( _! own weight4 ,ano!r exp]im5t :i* a/oni%$ 8 audi5ce 0 p]=m$ ) ! cyl9d] ( a l>ge pump 7,fig4 #e74 ,a rope 0 ti$ to ! pi/on4 ,?is rope 0 pass$ ov] a pulley1 & a l>ge numb] ( m5 appli$ _! /r5g? to ! rope to hold ! pi/on 9 place4 ,:5 ! air 0 tak5 out ( ! cyl9d]1 ! pi/on 0 =c$ d[n by air-pressure1 & ! m5 7 lift$ viol5tly f ! gr\nd4 ,?is exp]im5t1 z we %all see1 0 ( great importance 9 ! inv5tion ( ! /eam-eng9e4 ,illu/ration3 ,,fig4 #e--;,,gu]icke',s ,,air-,,pump ,m5 lift$ f ! gr\nd by air-pressure4 ,gu]icke's /udy ( air-pressure l$ him to make a wat] b>omet] 7,fig4 #f74 ,?is consi/$ ( a glass tube ab\t ?irty feet long dipp+ into a di% ( wat]4 ,! tube 0 fill$ ) wat]1 & ! top project$ above ! ro( ( ! h\se4 ,on ! wat] 9 ! tube he plac$ a wood5 image ( a man4 ,9 fair wea!r ! image w\ld be se5 above ! h\setop4 ,on ! approa* ( a /orm ! image w\ld drop out ( sight4 ,?is l$ 8 sup]/iti\s neighbors to accuse him ( be+ 9 league ) ,satan4 ,illu/ration3 ,,fig4 #f--;,,gu]icke',s ,,wat] ,,b>omet] ,9 fair wea!r ! image appe>$ above ! h\setop4 ,:5 a /orm 0 approa*+ ! image dropp$ bel[ ! ro( into ! h\se4 ,! fir/ electrical ma*9e 0 made by ,gu]icke4 ,?is 0 simply a globe ( sulphur turn+ on a wood5 axle4 ,he obs]v$ t :5 ! dry h& 0 held aga9/ ! revolv+ globe1 ! globe w\ld attract bits ( pap] & o!r light objects4 ,rob]t ,boyle & ! ,pressure ( ,air & ,/eam ,rob]t ,boyle1 9 ,engl&1 improv$ ! air-pump & p]=m$ _m new & int]e/+ exp]im5ts ) x4 ,"o ( 8 exp]im5ts 0 to make wat] boil by means ( an air-pump )\t apply+ heat4 ,x is n[ well kn[n t wat] :5 boil+ on a high m\nta9 is n s hot z :5 boil+ d[n 9 ! valley4 ,?is is because ! air-pressure is less on ! m\nta9 top ?an 9 ! valley4 ,by us+ an air-pump to remove ! air-pressure1 wat] may be made to boil :5 x is /ill q cold to ! h&4 ,boyle comp>$ ! action ( air "u pressure to a /eel spr+4 ,! spr+ ( ! air is evid5t to u 9 ! pneumatic tire ( ! bicycle or automobile4 ,boyle f\nd t ! m air is compress$ ! great] is its pressure or spr+1 & t /eam z x exp&s ex]ts less & less pressure4 ,?is is important 9 ! /eam-eng9e4 ,pascal & ! ,hydraulic ,press ,x 0 ,blaise ,pascal1 a ,fr5*man1 :o prov$ beyond ! possibility ( a d\bt t air-pressure supports ! m]cury 9 a b>omet]1 & lifts ! wat] 9 a pump 7,fig4 #g74 ,he _h two m]cury b>omet]s exactly alike set up at ! foot ( a m\nta94 ,! m]cury /ood at ! same height 9 ea*4 ,!n "o b>omet] 0 left at ! foot ( ! m\nta91 & ! o!r 0 c>ri$ to ! summit1 ab\t ?ree ?\s& feet high4 ,! m]cury 9 ! second b>omet] !n /ood m ?an ?ree in*es l[] ?an at fir/4 ,z ! b>omet] 0 c>ri$ d[n ! m\nta9 ! m]cury sl[ly rose until1 at ! foot1 x /ood at ! same height z at fir/4 ,! p>ty /opp$ ab\t half-way d[n ! m\nta91 all[+ ! b>omet] to re/ !re = "s "t1 & obs]v+ x c>efully4 ,!y f\nd t ! m]cury /ood ab\t an in* & a half high] ?an at ! foot ( ! m\nta94 ,dur+ all ?is "t ! height ( ! m]cury 9 ! b>omet] :i* _h be5 left at ! foot ( ! m\nta9 did n *ange4 ,illu/ration3 ,,fig4 #g--;,a ,,lift-,,pump ,air press+ d[n on ! wat] 9 ! well causes ! wat] to rise 9 ! pump4 ,! air c d ?is only :5 ! plung] is at "w remov+ air or wat] & r$uc+ ! pressure inside ! pump4 ,x is n[ kn[n t :5 a b>omet] is c>ri$ up to a height ( n9e hundr$ feet1 ! m]cury /&s an in* l[] ?an at ! e>?'s surface4 ,= e n9e hundr$ feet ( elevation ! m]cury is l[]$ ab\t "o in*4 ,9 ?is way ! height ( a m\nta9 c be measur$1 & a man 9 a balloon or an air-%ip c tell at :at height he is sail+4 ,= ?is purpose1 h[ev]1 a b>omet] is us$ t is m easily c>ri$ ?an a m]cury b>omet]4 ,pascal inv5t$ ! hydraulic press1 a ma*9e ) :i* he said he c\ld multiply pressure to any ext5t1 :i* rem9ds u ( ,ar*im$es' say+ t1 ) 8 own h&1 he c\ld move ! e>? if only he _h a place to /&4 ,pascal c\ld s arrange 8 ma*9e t a man press+ ) a =ce ( a hundr$ p\nds on ! h&le c\ld produce a pressure ( _m tons4 ,9 fact1 a man c s arrange ?is ma*9e t he c lift any weight :atev] 7,fig4 #h74 ,illu/ration3 ,,fig4 #h--;,a ,,simple ,,hydraulic ,,press ,a "o-p\nd weight holds up a hundr$ p\nds4 ,! hydraulic press has two cyl9d]s4 ,"o cyl9d] mu/ be l>g] ?an ! o!r4 ,! two cyl9d]s are fill$ ) a liquid1 z wat] or oil1 & are connect$ by a tube s t ! liquid c fl[ f "o cyl9d] into ! o!r4 ,!re is a tightly fitt+ pi/on 9 ea* cyl9d]4 ,if "o pi/on has an area ( "o squ>e in*1 & ! o!r has an area ( "o hundr$ squ>e in*es1 !n e p\nd ( pressure on ! small pi/on causes a hundr$ p\nds ( pressure on ! l>ge pi/on4 ,a hundr$ p\nds on ! small pi/on w\ld lift a weight ( t5 ?\s& p\nds on ! l>ge pi/on4 ,b we c see t ! l>ge pi/on _c move z fa/ z ! small "o does4 ,?\gh we c lift a v heavy weight ) ?is ma*9e1 we mu/ expect ?is heavy weight to move sl[ly4 ,!re mu/ be a loss 9 spe$ to make up = ! ga9 9 ! weight lift$ 7,fig4 #i74 ,an hydraulic press ) belt-driv5 pump is illu/rat$ 9 ,fig4 #aj4 ,illu/ration3 ,,fig4 #i--;,,h[ ,,an ,,hydraulic ,,press ,,works ,"o man ) ! ma*9e c ex]t z mu* pressure z a hundr$ m5 c\ld )\t ! ma*9e4 ,! arr[s %[ ! direction 9 :i* ! liquid is =c$ by ! action ( ! plung] p4 ,! l>ge pi/on ,p is =c$ up1 ?us compress+ ! pap]4 ,illu/ration3 ,,fig4 #aj--;,,an ,,hydraulic ,,press ,,) ,,belt-,,driv5 ,,pump ,newton ,sir ,isaac ,newton z a boy did n %[ any unusual tal5t4 ,9 s*ool he 0 backw>d & inatt5tive = a numb] ( ye>s1 until "o day ! boy above him 9 class gave him a kick 9 ! /oma*4 ,?is r\s$ him &1 to av5ge ! insult1 he appli$ himself to /udy & quickly pass$ above 8 (f5d+ classmate4 ,8 /rong _s 0 ar\s$1 & he soon took up 8 position at ! head ( 8 class4 ,x 0 8 delight to inv5t amusem5ts = 8 classmates4 ,he made pap] kites1 & c>efully ?\ght out ! be/ %ape = a kite & ! numb] ( po9ts to :i* to atta* ! /r+4 ,he w\ld atta* pap] lant]ns to ^! kites & fly !m on d>k nights1 to ! delight ( 8 companions & ! dismay ( ! sup]/iti\s c\ntry p1 :o mi/ook !m = comets port5d+ "s great calamity4 ,he made a toy mill to be run by a m\se1 :i* he call$ ! mill]2 a me*anical c>riage1 run by a h&le work$ by ! p]son inside1 a wat]-clock1 ! h& ( :i* 0 turn$ by a piece ( wood :i* fell or rose by ! action ( dropp+ wat]4 ,at ! age ( fifte51 8 "m1 !n a wid[1 remov$ him f s*ool to take *>ge ( ! family e/ate4 ,b ! f>m 0 n to 8 lik+4 ,! %eep w5t a/ray1 & ! cattle trod d[n ! corn :ile he 0 p]us+ a book or work+ ) "s ma*9e ( 8 own con/ruction4 ,8 "m wisely p]mitt$ him to return to s*ool4 ,aft] complet+ ! c\rse 9 ! village s*ool he ent]$ ,tr9ity ,college1 ,cambridge4 ,gravitation ,x 0 9 ! ye> foll[+ 8 graduation f ,cambridge t he made 8 greate/ discov]y--t ( ! law ( gravitation4 ,a plague _h brok5 out 9 ,cambridge1 to escape :i* ,newton _h retir$ to 8 e/ate at ,wool/horpe4 ,"h he 0 sitt+ "o day alone 9 ! g>d5 ?9k+ ( ! wond]ful p[] :i* causes all bodies to fall t[>d ! e>?4 ,! same p[]1 he ?\ght1 :i* causes an apple to fall to ! gr\nd causes bodies to fall on ! tops ( ! highe/ m\nta9s & 9 ! deepe/ m9es4 ,may x n ext5d f>!r ?an ! tops ( ! m\nta9s8 ,may x n ext5d ev5 z f> z ! moon8 ,&1 if x does1 is n ?is p[] alone able to hold ! moon 9 its orbit1 z x b5ds into a curve a /one ?r[n f ! h&8 ,!re foll[$ a long calculation requir+ ye>s to complete4 ,see+ t ! results 7 likely to prove 8 !ory ( gravitation1 he 0 s ov]come t he c\ld n f9i% ! "w4 ,:5 ?is 0 done by "o ( 8 fri5ds1 x 0 f\nd t ,newton's ?\ght 0 correct--t ! =ce ( gravitation :i* causes bodies to fall at ! e>?'s surface is ! same z ! =ce :i* holds ! moon 9 its orbit4 ,z ! e>? & moon attract ea* o!r1 s e /> & planet attracts e o!r /> & planet1 & ?is attraction is gravitation4 ,colors 9 ,sunlight ,ab\t ! same "t t he made 8 fir/ discov]ies reg>d+ gravitation1 he took up ! /udy ( light ) a view to improv+ ! con/ruction ( telescopes4 ,8 fir/ exp]im5t 0 to admit sunlight into a d>k5$ room ?r\gh a circul> hole 9 ! %utt]1 & all[ ?is beam ( light to pass ?r\gh a glass prism to a :ite scre5 beyond4 ,he expect$ to see a r\nd spot ( light1 b to 8 surprise ! light 0 drawn out into a b& ( brilliant colors4 ,he f\nd t ! light :i* comes f ! sun is n a simple ?+1 b is compos$ ( colors1 & ^! colors 7 sep>at$ by ! glass prism4 ,9 ! same way ! colors ( sunlight are sep>at$ by ra9drops to =m a ra9b[4 ,! colors may be aga9 m+l$ toge!r by pass+ !m ?r\gh a second prism4 ,!y w !n =m a :ite light4 ,suppose t ! light ( ! sun 7 n compos$ ( diff]5t colors1 t all p>ts ( :ite light 7 alike1 !n !re w\ld be no colors 9 nature4 ,all ! trees & fl[]s w\ld h a dull1 lead5 hue1 & ! human c\nt5ance w\ld h ! appe>ance ( a p5cil-sket* or a photographic picture4 ,! ra9b[ itself w\ld dw9dle into a n>r[ ar* ( :ite light2 ! sun w\ld %9e ?r\gh a gray sky1 & ! beauty ( ! sett+ sun w\ld be replac$ by ! gray ( twilight 7,fig4 #aa74 ,illu/ration3 ,,fig4 #aa--,,newton',s ,,exp]im5t ,,) ,,! ,,prism ,sunlight sep>at$ into ! colors ( ! ra9b[4 ,! sev5 colors are3 violet1 indigo1 blue1 gre51 yell[1 orange1 r$4 ,"o ( ,newton's inv5tions 0 a reflect+ telescope--t is1 a telescope 9 :i* a curv$ mirror 0 us$ 9 place ( a l5s4 ,he made su* a telescope only six in*es long1 :i* w\ld magnify =ty times4 ,newton 0 a memb] ( ! ,conv5tion ,p>liam5t1 :i* decl>$ ,james ,,ii4 to be no long] ,k+ ( ,engl& & t5d]$ ! cr[n to ,william & ,m>y4 ,he 0 made a knight by ,que5 ,anne 9 #agje4 ,8 k ( *emi/ry 0 us$ 9 ! s]vice ( 8 c\ntry :5 he 0 ,ma/] ( ! ,m9t4 ,x 0 8 duty to sup]9t5d ! reco9+ ( ! money ( ,engl&1 :i* _h be5 debas$ by di%one/ (ficials at ! m9t4 ,he did 8 "w )\t fe> or favor4 ,once a bribe ( #fjjj 7#cj1jjj7 0 (f]$ him4 ,he refus$ x1 :]eupon ! ag5t :o made ! (f] said to him t x came f a great du*ess4 ,newton repli$3 ,tell ! lady t if %e 7 "h h]self1 & _h made me ?is (f]1 ,i w\ld h desir$ h] to g out ( my h\se2 & s ,i desire y1 or y %all be turn$ out4 ,al?\gh ,newton's discov]ies 9 ! _w ( ?\ght 7 among ! greate/ ev] made by man1 he reg>d$ !m z insignificant comp>$ ) ! tru? yet undiscov]$4 ,he said ( himself3 ,i d n "k :at ,i may appe> to ! _w1 b to myself ,i seem to h be5 only l a boy play+ on ! sea-%ore & div]t+ myself 9 n[ & !n f9d+ a smoo!r pebble or a pretti] %ell ?an ! ord9>y1 :il/ ! great ocean ( tru? lay all undiscov]$ be=e me4 ,*apt] ,,iii ,,! ,,eighte5? ,,c5tury ,james ,watt & ! ,/eam-,eng9e ,if y _h visit$ ! coal-m9es ( ,engl& & ,scotl& ?ree hundr$ ye>s ago1 y might h se5 wom5 b5d+ "u baskets ( coal toil+ up spiral /airways lead+ f ! dep?s ( ! m9es4 ,at "s ( ! m9es horses 7 us$4 ,a comb9ation ( w9dlass & pulleys made x possible = a horse to lift a heavy bucket ( coal4 ,!re came a "t1 h[ev]1 :5 sl[ & crude me?ods su* z ^! c\ld n supply ! coal z fa/ z x 0 ne$$4 ,! %all[] m9es 7 be+ exhau/$4 ,! m9es mu/ be dug deep]4 ,! dem& = coal 0 increas+4 ,! supply ( coal1 x 0 ?\ght1 w\ld n la/ until ! end ( ! c5tury4 ,! wood supply 0 already exhau/$4 ,x seem$ t ,engl& 0 fac+ a fuel fam9e4 ,!re 0 only "o way out ( ! difficulty4 ,a ma*9e mu/ be inv5t$ t w\ld d ! "w ( ! wom5 & horses1 a ma*9e /rong en\gh to raise coal ) spe$ f ! deepe/ m9es4 ,!n x happ5$ t two great inv5tors1 ,newcom5 & ,watt1 arose to produce ! ma*9e t 0 ne$$4 ,:5 ! _w ne$s an inv5tion x seldom fails to appe>4 ,x is true ( ! _w1 z ( an individual1 t ,necessity is ! "m ( inv5tion4 ,9 ! mean "t ,torricelli _h p]=m$ 8 fam\s b>omet] exp]im5t1 & ,otto von ,gu]icke _h a/oni%$ pr9ces ) pro(s ( ! pressure ( ! air4 ,!re 0 no app>5t connection betwe5 ^! exp]im5ts & ! art ( coal-m9+1 yet ^! discov]ies made possible ! /eam-eng9e :i* 0 to revolutionize fir/ ! coal-m9+ indu/ry &1 lat]1 ! entire indu/rial _w4 ,! ,fir/ ,/eam-,eng9e ) a ,pi/on ,! fir/ /eam-eng9e ) a pi/on 0 made by ,d5ys ,pap91 a ,fr5*man4 ,pap9 _h obs]v$ t1 9 ,gu]icke's exp]im5t1 air-pressure lift$ sev]al m5 (f _! feet4 ,s he ?\ght ! air c\ld be made to lift heavy weights & d useful "w4 ,b h[ %\ld he produce ! vacuum8 ,8 fir/ ?\ght 0 to explode gunp[d] b5ea? ! pi/on4 ,! gunp[d] eng9e _h be5 tri$ by o!rs & f\nd want+4 ,he next turn$ 8 att5tion to /eam1 & discov]$ t if ! pi/on 7 =c$ up by /eam & !n ! /eam cond5s$1 a vacuum 0 =m$ b5ea? ! pi/on1 & air-pressure =c$ ! pi/on to desc5d4 ,if ! pi/on 7 atta*$ to a weight by a rope pass+ ov] a pulley1 !n1 z ! pi/on desc5d$1 x w\ld lift ! weight4 ,pap9's eng9e consi/$ simply ( a cyl9d] & pi/on 7,fig4 #ab74 ,!re 0 no boil]1 b ! wat] 0 plac$ 9 ! cyl9d] b5ea? ! pi/on4 ,a fire 0 plac$ "u ! cyl9d] &1 z ! wat] boil$1 ! /eam rais$ ! pi/on4 ,!n ! fire 0 remov$ &1 z ! cyl9d] cool$1 ! /eam cond5s$1 & ! pi/on 0 =c$ d[n by air-pressure4 ,?is 0 a sl[ & awkw>d me?od4 ,! eng9e requir$ sev]al m9utes to make "o /roke4 ,illu/ration3 ,,fig4 #ab--,,pap9',s ,,eng9e ,! fir/ /eam-eng9e ) a pi/on4 ,:5 ! pi/on ,b 0 =c$ d[n by air-pressure1 a weight 0 lift$ by means ( a rope ,,tt pass+ ov] pulleys4 ,! pr9ciple ( ,pap9's eng9e 0 fir/ successfully appli$ by ,?omas ,newcom54 ,newcom5 0 a blacksmi? by trade1 & 8 great successor1 ,watt1 0 a me*anic4 ,?us we see t great discov]ies soon become common prop]ty4 ,! blacksmi? & ! me*anic soon le>n to use ! discov]ies ( ! sci5ti/4 ,newcom5's ,eng9e ,9 ! ,newcom5 eng9e ! pi/on mov$ a walk+-beam to :i* 0 atta*$ a pump-rod4 ,/eam 0 us$ m]ely to balance ! air-pressure on ! pi/on & all[ ! pump-rod to desc5d by its own weight4 ,! /eam 0 cond5s$ 9 ! cyl9d]1 & ! pressure ( ! air =c$ ! pi/on d[n4 ,?us ! "w ( rais+ wat] 9 ! pump 0 done by ! air4 ,newcom5's fir/ eng9e made twelve /rokes a m9ute1 & at ea* /roke lift$ fifty gallons ( wat] fifty y>ds4 ,he us$ ?is eng9e 9 pump+ wat] f ! m9es1 & also made eng9es = lift+ coal4 ,at fir/ ! /eam 0 cond5s$ by ?r[+ cold wat] on ! outside ( ! cyl9d]4 ,b "o day ! eng9e sudd5ly increas$ its spe$ & cont9u$ to "w ) unusual rapidity4 ,! upp] side ( ! pi/on 0 cov]$ ) wat] to make ! pi/on air-tight1 & x 0 f\nd t ?is wat] 0 ent]+ ! cyl9d] ?r\gh a hole t _h worn 9 ! pi/on1 & ?is jet ( cold wat] 0 rapidly cond5s+ ! /eam4 ,?is 0 ! orig9 ( jet cond5sation4 ,aft] ?is /eam & wat] 7 alt]nately admitt$ to ! cyl9d] ?r\gh cocks turn$ by h&4 ,a boy1 ,humphrey ,pott]1 to :om ?is "w 0 intru/$1 won fame by ty+ /r+s to ! cocks 9 su* a way t ! eng9e w\ld turn ! cocks itself & ! boy1 ,humphrey1 0 free to play4 ,?is device 0 ! orig9 ( valve-ge>4#a #a ,any device by :i* a /eam-eng9e op]ates ! valves :i* admit /eam to ! cyl9d] is call$ valve-ge>4 ,"o =m ( valve-ge> is ! l9k motion inv5t$ by ,/eph5son4 ,?is =m w be describ$ 9 connection ) ! locomotive4 ,a simple valve-rod1 work$ by an ecc5tric su* z is us$ on mo/ /ation>y eng9es1 is also a =m ( valve-ge>4 ,newcom5's eng9e 0 ext5sively us$4 ,! t9 & copp] m9es ( ,cornwall 7 deep5$4 ,coal-m9es 7 sunk to twice ! dep? t _h be5 possible4 ,b z ! m9es 7 deep5$ ! co/ ( runn+ ! eng9es increas$4 ,! l>ge/ eng9es consum$ ab\t #ae1jjj wor? ( coal p] ye>4 ,! ,newcom5 eng9e requir$ ab\t tw5ty-eight p\nds ( coal p] h\r p] horse-p[]1 :ile a mod]n eng9e consumes less ?an two p\nds4 ,aga91 because ( increas$ co/1 m9es 7 be+ ab&on$4 ,su* 0 ! situation :5 ,james ,watt came into ! field ( action4 ,watt _h le>n$ ! me*anic's trade 9 "o ye> 9 a ,london %op1 &1 because he _h n pass$ ?r\gh an appr5tice%ip ( sev5 ye>s1 ! ,guild ( ,hamm]m51 a labor-union ( 8 "t1 refus$ him admission1 & ?is refusal meant no employm5t4 ,he f\nd %elt]1 h[ev]1 9 ! ,univ]sity ( ,glasg[1 & 0 !re provid$ ) a small work%op :]e he c\ld make in/rum5ts = sale4 ,watt's ,eng9e ,a small ,newcom5 eng9e belong+ to ! ,univ]sity ( ,glasg[ 0 out ( repair4 ,london me*anics _h fail$ to make x "w4 ,! job 0 giv5 to ,watt4 ,t he might d a p]fect piece ( "w on ?is eng9e1 he made a /udy ( all t 0 !n kn[n relat+ to /eam 7,fig4 #ac74 ,illu/ration3 ,,fig4 #ac--,,! ,,newcom5 ,,eng9e1 ,,9 ,,repair+ ,,:i* ,,watt ,,0 ,,l$ ,,to ,,8 ,,great ,,discov]ies ,pres]v$ 9 ! ,univ]sity ( ,glasg[4 ,he saw t !re 0 a great loss ( heat 9 admitt+ cold wat] into ! cyl9d] to cond5se ! /eam1 & t1 to prev5t ?is loss1 ! cyl9d] mu/ be kept always z hot z ! /eam t ent]s x4 ,:ile ?9k+ ^u ?is problem ! idea came to him t1 if connection 7 made betwe5 ! cyl9d] & a tank f :i* ! air _h be5 pump$ out1 ! /eam w\ld ru% into ! tank1 & might !re be cond5s$ )\t cool+ ! cyl9d]4 ,?is 0 ! orig9 ( ! cond5s]4 ,we h se5 t1 9 ! ,newcom5 eng9e1 ! /eam act$ only on ! "u side ( ! pi/on1 air act+ on ! upp] side4 ,x occurr$ to ,watt t ! /eam %\ld act on bo? sides ( ! pi/on4 ,s he propos$ to put an air-tight cov] on ! cyl9d] ) a hole & /uff+-box = ! pi/on to slide ?r\gh & to admit /eam to act ^u x in/ead ( air4 ,?us he 0 l$ to inv5t ! d\ble-act+ eng9e4 ,! action 9 ! cyl9d] ( ,watt's eng9e 0 ! same z t ( ! mod]n eng9e4 ,to save ! p[] ( /eam1 ,watt arrang$ ! valve 9 8 eng9e 9 su* a way t ! /eam 0 cut (f f ! cyl9d] :5 ! pi/on _h made ab\t "o-f\r? ( a /roke4 ,! /eam 9 ! cyl9d] cont9ues to exp& & drive ! pi/on4 ,?is device m ?an d\bles ! am\nt ( "w t ! /eam w d 7,fig4 #ad74 ,illu/ration3 ,,fig4 #ad--;,,cyl9d] ,,( ,,watt',s ,,/eam-,,eng9e ,arr[s %[ ! c\rse ( ! /eam4 ,horse-,p[] ( an ,eng9e ,:5 horses 7 ab\t to be replac$ by ! /eam-eng9e at ! m9es1 ! "q 0 ask$3 ,h[ _m horses w ! eng9e replace8 ,te/s 7 made by ,watt & o!rs be=e him ( ! rate at :i* a horse c\ld "w 9 pump+ wat] or 9 lift+ a weight by means ( a pulley4 ,watt's exp]im5ts %[$ t a good ,london horse c\ld g on lift+ #aej p\nds ov] a pulley at ! rate ( #b-a_/b miles an h\r or #bbj feet p] m9ute1 & cont9ue ! "w eight h\rs a day4 ,?is w\ld be equal to lift+ #cc1jjj p\nds "o foot high e m9ute4 ,?is rate ( do+ "w he call$ a horse-p[]4 ,x is m ?an ! av]age horse c d1 b ?is numb] 0 us$ by ,watt t he might give good measure 9 8 eng9es4 ,! horse-p[] ( an eng9e at t "t meant ! rate ( "w 9 lift+ wat] or coal4 ,n[ x means ! rate ( "w done by ! /eam ^u ! pi/on1 s t to f9d ! useful horse-p[] ( an eng9e we mu/ d$uct ! "w wa/$ 9 friction4 ,! indicator = measur+ ! pressure ( /eam 9 ! cyl9d] & ! fly-ball gov]nor are also inv5tions made by ,watt 7,fig4 #ae74 ,! fly-ball gov]nor replac$ ! ?rottle-valve :i* 0 at fir/ us$ by ,watt to regulate ! spe$ ( 8 eng9es4 ,! ?rottle-valve is /ill us$ on locomotives4 ,illu/ration3 ,,fig4 #ae--;,a ,,fly-,,ball ,,gov]nor ,! balls z !y rotate regulate ! admission ( /eam to ! cyl9d] by means ( ! lev] ,l & ! rod ,r4 ,at ! end ( ! eighte5? c5tury ! /eam-eng9e 0 full gr[n4 ,x rema9$ = ! n9ete5? c5tury to apply ! eng9e to locomotion on sea & l&1 to develop ! /eam-turb9e1 & s to increase ! p[] ( ! /eam-eng9e t1 e>ly 9 ! tw5tie? c5tury1 a #fh1jjj-;horse-p[] eng9e %\ld spe$ an ocean l9] across ! ,atlantic 9 five days4 ,! ,leyd5 ,j> ,! fir/ electrical inv5tion ( practical use 0 made by ,b5jam9 ,frankl94 ,9 ,frankl9's "t great int]e/ 9 electricity _h be5 ar\s$ by ! /range discov]y ( a ,g]man pr(essor1 ,piet] van ,muss*5broek1 ( ! ,univ]sity ( ,leyd54 ,?is pr(essor _h tri$ :at he call$ a new b t]rible exp]im5t4 ,he _h susp5d$ by two silk ?reads a gun-b>rel :i* receiv$ electricity f an electrical ma*9e4 ,f "o end ( ! gun-b>rel hung a brass wire4 ,! l[] end ( ?is wire dipp$ 9 a j> ( wat]4 ,he held ! j> 9 "o h&1 :ile ) ! o!r he tri$ to draw sp>ks f ! gun-b>rel4 ,sudd5ly he receiv$ a %ock :i* seem$ to him l a lightn+ /roke4 ,s viol5t 0 ! %ock t he ?\ght = a mom5t x w\ld end 8 life4 ,out ( ?is exp]im5t came ! ,leyd5 j>1 :i* = a c5tury & a half 0 ( no practical use1 b :i* n[ =ms an important "p ( e wireless telegraph equipm5t4 ,! ,leyd5 j> is simply a glass bottle or j> coat$ ) t9-foil bo? inside & outside 7,fig4 #af74 ,:5 *>g$ ) electricity ! j> w hold its *>ge until ! two coat+s are connect$ by a metal wire or o!r good conductor ( electricity4 ,a p]son may receive a /rong %ock by hold+ ! j> 9 "o h& & t\*+ a knob connect$ to ! inn] coat+ ) ! o!r h&4 ,illu/ration3 ,,fig4 #af--;,a ,,leyd5 ,,j> ,popul> int]e/ 9 electricity 0 ar\s$ by ?is discov]y4 ,! friction electrical ma*9e & ! ,leyd5 j> 7 simple & easy to make4 ,p ( fa%ion f\nd !m int]e/+ & amus+1 ! m s because ( ! %ock felt on tak+ ?r\gh ! body ! dis*>ge f ! wond]ful bottle1 & ! fact t sev]al p]sons c\ld receive ! %ock at ! same in/ant4 ,on "o occasion ! ,abb ,nollet dis*>g$ a ,leyd5 j> ?r\gh a l9e compos$ ( all ! monks ( ! ,c>?usian ,mona/]y 9 ,p>is4 ,z ! l9e ( s]i\s-fac$ monks a mile 9 l5g? jump$ into ! air1 ! effect 0 ridicul\s 9 ! extreme4 ,conductors & ,insulators ,ab\t ?is "t o!r great electrical discov]ies 7 made4 ,e>ly 9 ! c5tury1 ,/eph5 ,gray discov]$ t "s objects conduct electricity & o!rs d n4 ,he discov]$ t1 :5 a glass tube is electrifi$ by rubb+1 x w attract & repel light objects4 ,9 ! same way a comb or p5hold] ( rubb] may be electrifi$ by rubb+ x on ! sleeve4 ,a bit ( pap] :i* t\*es ! comb becomes electrifi$4 ,electricity c be transf]r$ f "o object to ano!r4 ,gray discov]$ fur!r t contact is n necess>y1 t a hemp5 ?read or a wire w c>ry an electric *>ge f "o object to ano!r4 ,a silk ?read w n c>ry ! electric *>ge4 ,"s ?+s convey electricity1 he said1 & "s d n1 & ^? :i* d n c be us$ to prev5t ! electricity escap+ f ^? :i* d4 ,c\ld ?is obscure inv5tor h se5 a mod]n telegraph l9e ) ! glass insulators on ! poles1 :i* prev5t ! electric curr5t escap+ f ! telegraph wire1 he might h realiz$ ! importance ( 8 discov]y4 ,he set up a l9e ( hemp5 ?read six hundr$ & fifty feet long1 & ) an electrical ma*9e at "o end ( ! l9e electrifi$ a boy susp5d$ f ! o!r end4 ,two ,k9ds ( ,electric ,*>ge ,a ,fr5*man1 ,du,fay1 :ile c>ry+ fur!r ! exp]im5ts ( ,gray1 0 wat*+ a bit ( gold-leaf float+ 9 ! air4 ,! gold-leaf _h be5 repell$ aft] contact ) 8 electrifi$ glass tube4 ,?9k+ to try ! action ( two electrifi$ objects on ! gold leaf1 he rubb$ a piece ( gum-copal & br\ght x ne> ! leaf4 ,to 8 a/oni%m5t ! leaf1 :i* 0 repell$ by ! glass tube1 0 attract$ by ! gum-copal4 ,he repeat$ ! exp]im5t aga9 & aga91 & ea* "t ! leaf 0 repell$ by ! glass & attract$ by ! gum4 ,he conclud$ f ?is t !re are two k9ds ( electricity1 :i* he nam$ vitre\s & res9\s4 ,! two k9ds ( electric *>ge 7 call$ by ,frankl9 positive & negative4 ,frankl9 made a batt]y ( ,leyd5 j>s1 connect+ ! inn] coat+ ( "o to ! out] coat+ ( ! next ?r\gh\t ! s]ies4 ,9 ?is way he c\ld get a mu* /rong] sp>k ?an ) a s+le j>4 ,on "o occasion he ne>ly lo/ 8 life by tak+ a %ock f 8 batt]y ( ,leyd5 j>s4 ,he magnetiz$ & demagnetiz$ /eel ne$les by pass+ ! dis*>ge f 8 ,leyd5 j>s ?r\gh ! ne$les4 ,frankl9's ,kite ,exp]im5t ,! conjecture t lightn+ is ( ! same nature z ! sp>k f ! ,leyd5 j> or ! electrical ma*9e _h ga9$ a hold on ! m9ds ( o!rs be=e ,frankl94 ,9 ,france sp>ks _h be5 drawn f a rod n9ety-n9e feet high1 b ?is did n rea* into ! cl\ds4 ,frankl9 det]m9$ to s5d a kite into a ?und]-cl\d1 ?9k+ electricity f ! cl\d w\ld foll[ ! /r+ ( ! kite & c\ld be /or$ 9 a ,leyd5 j>1 & us$ l ! *>ge f an electrical ma*9e4 ,he _h felt ! p[] ( a ,leyd5-j> dis*>ge1 & ?r\gh x _h ne>ly lo/ 8 life4 ,he knew t lightn+ is f> m p[]ful ?an any batt]y ( ,leyd5 j>s1 & yet to te/ ! tru? ( 8 !ory1 t lightn+ is an electrical dis*>ge1 he 0 ab\t to draw ! lightn+ to 8 h&4 ,he knew little ( conductors ( electricity4 ,:e!r ! cord w\ld draw little or mu* ( ! electric fire he knew n4 ,s f> z he knew he 0 toy+ ) dea?4 ,! kite 0 made ( two light /rips ( c$> plac$ crosswise1 & a l>ge silk h&k]*ief fa/5$ to ! /rips4 ,a %>p wire ab\t a foot long 0 fa/5$ to "o ( ! /rips4 ,to ! l[] end ( ! cord he atta*$ a key & a silk ribbon4 ,by means ( ! ribbon he held ! cord to insulate x f 8 h&4 ,! kite so>$ into ! cl\ds1 & ,frankl9 & 8 son /ood "u a %$ await+ ! com+ ( ! electric fire 7,fig4 #ag74 ,soon ! fibres ( ! cord began to bri/le up4 ,he approa*$ 8 knuckles to ! key4 ,a sp>k pass$4 ,he br\ght up a ,leyd5 j> & *>g$ x ) electricity f ! cl\d1 & f\nd t ) ?is *>ge he c\ld d ev]y?+ t c\ld be done ) electricity f 8 ma*9e4 ,he _h prov$ ! id5tity ( lightn+ & electricity4 ,illu/ration3 ,,fig4 #ag--;,,frankl9',s ,,kite ,,exp]im5t ,tak+ electricity f ! cl\ds4 ,! ,lightn+-,rod ,"s "t be=e1 he _h discov]$ ! action ( a po9t 9 dis*>g+ electricity4 ,he said3 ,if y fix a ne$le to ! end ( a gun-b>rel l a little bayonet1 :ile x rema9s !re ! gun-b>rel _c be electrifi$ s z to give a sp>k1 = ! electric fire cont9ually runs out sil5tly at ! po9t4 ,9 ! d>k y may see a light ga!r ^u ! po9t l t ( a firefly or gl[-worm4 ,if ! ne$le is held 9 ! h& & br\ght ne> to an object *>g$ ) electricity1 ! object is quietly dis*>g$1 & a light may be se5 at ! po9t ( ! ne$le4 ,?is action ( po9ts expla9s ! light sometimes se5 on ! tops ( %ips' ma/s1 call$ by sailors ,sa9t ,elmo's fire1 & p]haps1 also1 ! obs]vation ( ,cs> t1 9 a c]ta9 ,african ,w>1 ! spe>s ( ! ,fif? ,roman ,legion appe>$ tipp$ ) fire4 ,! lightn+-rod 0 ! outcome ( ,frankl9's obs]vations1 & ?is 0 ! fir/ practical inv5tion relat+ to electricity4 ,a build+ may be electrifi$ by an electrifi$ cl\d pass+ ov] x4 ,if ! build+ is protect$ by po9t$ rods1 ! electric *>ge w quietly escape f ! po9ts4 ,! l[] ends ( ! rods mu/ be 9 ! moi/ e>? bel[ ! surface4 ,! lightn+-rod has n prov$ s great a protection z ,frankl9 suppos$ x w\ld4 ,he suppos$ t a lightn+-/roke is a dis*>ge 9 "o direction only2 b we n[ "k t x is a rapid surg+ back & =?1 & ?is fact acc\nts = ! failure ( ! lightn+-rods to furni% p]fect protection4 ,9 surg+ back & =?1 ! lightn+ may skip f ! lightn+-rod to "s metal object )9 ! build+1 z a /ove or radiator4 ,! lightn+-rod robb$ ! ?und]-/orm ( its t]rors to ! timid1 & 9 "t dispell$ ! sup]/ition ( p :o believ$ t ?und] & lightn+ are evid5ce ( ! wra? ( ! ,deity4 ,frankl9 0 ! fir/ to propose an answ] to ! "q3 ,:at is electricity8 ,he believ$ electricity to be a subtle fluid exi/+ 9 all objects4 ,if an object has m ?an a c]ta9 am\nt ( ?is fluid1 x is positively electrifi$2 if less ?an ?is am\nt1 x is negatively electrifi$4 ,! "o-fluid !ory ( ,frankl9 0 soon met by ! two-fluid !ory propos$ by ,rob]t ,symm]1 = ,frankl9's !ory _h fail$ to expla9 :y two bodies negatively electrifi$ %\ld repel ea* o!r4 ,accord+ to ,symm]1 an un*>g$ body conta9s an equal quantity ( two diff]5t electrical fluids4 ,an excess ( "o ( ^! produces a positive *>ge1 an excess ( ! o!r a negative *>ge4 ,symm]'s exp]im5ts are almo/ ludicr\s4 ,he wore two pairs ( silk /ock+s1 & f\nd t :ite & black silk worn toge!r became /rongly electrifi$4 ,:5 ! two /ock+s worn on "o foot 7 pull$ (f toge!r1 & !n sep>at$1 !y 7 f\nd to be electrifi$1 & attract$ ea* o!r s /rongly t a =ce ( ab\t "o p\nd 0 requir$ to sep>ate !m4 ,! two *>ges1 negative & positive1 c\ld1 h[ev]1 be sep>at$4 ,he ?\ght1 !re=e1 t !re are two electrical p[]s1 n "o1 z ,frankl9 believ$4 ,8 belief 0 /r5g!n$ by exam9+ a quire ( pap] ?r\gh :i* an electric sp>k _h pass$1 & f9d+ t ! edges ( ! holes 7 b5t two diff]5t ways1 z if ! hole _h be5 made 9 ! quire by draw+ two ?reads 9 contr>y directions ?r\gh x4 ,!re 0 a long controv]sy reg>d+ ! two !ories1 & nei!r q ga9$ possession ( ! field4 ,ea* conta9$ "s tru?1 & ea* _h its weak po9ts4 ,! two _h m 9 common ?an m5 at t "t ?\ght4 ,galvani & ! ,electric ,curr5t ,frankl9 _h prov5 t !re is electricity 9 ! atmosph]e1 & t lightn+ is an electric dis*>ge4 ,a widespread int]e/ 9 ! electricity ( ! atmosph]e foll[$ ?is discov]y4 ,aloisio ,galvani1 a physician 9 ,bologna1 ,italy1 9 attempt+ to le>n ! effect ( atmosph]ic electricity on ! n]ves & muscles ( ! human body1 made a discov]y :i* l$ to ! electric batt]y & a k ( electric curr5ts4 ,hav+ dissect$ a frog1 he laid x on a table on :i* /ood an electrical ma*9e4 ,:5 "o ( 8 assi/ants t\*$ lightly ! n]ve ( ! ?igh ) ! po9t ( a knife :ile a sp>k 0 drawn f ! electrical ma*9e1 ! muscles contract$ viol5tly1 z if !y 7 attack$ by a cramp4 ,:5 he held ! knife by ! bone h&le1 !re 0 no convulsion z !re 0 :5 he held x by ! /eel blade4 ,he next ?\ght x important to f9d out if lightn+ w\ld excite contraction ( ! muscles4 ,he /ret*$ & insulat$ a long iron wire 9 ! op5 air on ! h\setop &1 z a /orm drew ne>1 hung on x a dissect$ frog4 ,to ! feet he fa/5$ ano!r long iron wire1 :i* 0 all[$ to dip 9 ! wat] 9 ! well4 ,! result1 he said1 came ab\t z we wi%$4 ,z (t5 z ! lightn+ broke =?1 ! muscles 7 ?r[n into repeat$ viol5t convulsions1 s t always1 z ! lightn+ light5$ ! sky1 ! muscle contractions & movem5ts prec$$ ! ?und] &1 z x 71 ann\nc$ its com+4 ,x 0 be/1 h[ev]1 :5 ! lightn+ 0 /rong1 or ! cl\ds f :i* x broke =? 7 ne> ! place ( ! exp]im5t4 ,he describes 8 greate/ exp]im5t z foll[s3 ,aft] we _h inve/igat$ ! p[] ( atmosph]ic electricity 9 /orms1 our he>ts burn$ ) ! desire to inve/igate ! daily quiet electricity ( ! atmosph]e4 ,!re=e1 z ! prep>$ frogs1 hung on an iron rail+ :i* surr\nd$ a hang+ g>d5 on our h\se1 ) brass hooks ins]t$ 9 ! sp9al cord1 fell into convulsions n only :5 x light5$1 b :5 ! sky 0 calm & cle>1 ,i ?\ght t ! cause ( ^! contractions 0 ! *anges 9 ! electricity ( ! atmosph]e4 ,!n = h\rs1 yes1 ev5 days1 ,i obs]v$ ! animals1 b almo/ nev] a movem5t ( ! muscles c\ld be se54 ,at la/1 tir$ ) su* fruitless wait+1 ,i began to press ! brass hooks1 :i* 7 fa/5$ 9 ! sp9al cord1 aga9/ ! iron rail+ to see if su* a trick w\ld cause ! muscles to contract1 & if in/ead ( *anges 9 ! atmosph]ic electricity any o!r *anges w\ld h any influ5ce4 ,i obs]v$1 inde$1 vigor\s contractions1 b none :i* c\ld be caus$ by ! condition ( ! atmosph]e4 ,x 0 press+ ! brass hook aga9/ ! iron rail+1 ?us =m+ an electric batt]y1 t caus$ electricity to pass ?r\gh ! muscles ( ! frog4 ,galvani did n "k t he _h discov]$ a new s\rce ( electricity4 ,he nev] arriv$ at a correct explanation ( 8 results1 & nev] knew ! value ( 8 discov]y4 ,volta & ! ,electric ,batt]y ,x 0 left = ,alex&] ,volta to %[ t1 9 ,galvani's exp]im5t1 ! muscles ( ! frog1 toge!r ) ! brass hook & ! iron rail+1 =m$ an electric batt]y4 ,volta %[$ t an electric *>ge c be produc$ m]ely by br++ two diff]5t metals into contact4 ,he f\nd t1 if he plac$ copp] & z9c 9 sulphuric acid1 or a solution ( common salt1 he c\ld1 produce a cont9u\s fl[ ( electricity 7,fig4 #ah74 ,illu/ration3 ,,fig4 #ah--,,volta ,,expla9+ ,,8 ,,electric ,,batt]y ,,to ,,napoleon ,,bonap>te ,f a pa9t+4 ,photo by ,dubray4 ,9 ! beg9n+ ( ! ye> #ahjj ,volta made ! fir/ electric batt]y 7,fig4 #ai74 ,x 0 made ( copp] & z9c disks plac$ alt]nately1 ) a piece ( wet clo? above ea* pair ( disks4 ,) 8 column ( disks he c\ld obta9 a /rong %ock2 inde$1 _m %ocks1 "o aft] ! o!r4 ,?is fir/ batt]y ( ,volta's 0 a =m ( dry batt]y4 ,lat] ,volta devis$ 8 cr[n ( cups1 a =m ( wet batt]y simil> to "s batt]ies 9 use to-day4 ,ea* cup conta9$ a /rip ( copp] & a /rip ( z9c 9 dilute sulphuric acid4 ,illu/ration3 ,,fig4 #ai--,,! ,,fir/ ,,electric ,,batt]y ,no4 #a--;,a batt]y ( "o hundr$ pairs ( copp] & z9c disks4 ,no4 #b--,two su* batt]ies connect$4 ,by p]mission ( ! ,italian ,in/itute ( ,graphic ,arts1 ,b]gamo4 ,volta did n "k ! real use ( ! liquid 9 8 batt]y1 nor t ! /r5g? ( ! curr5t dep5ds on ! rate at :i* ! metal is dissolv$ by ! acid2 b he _h discov]$ ! electric curr5t1 & ) ?is discov]y began a new era 9 electrical inv5tion4 ,*apt] ,,iv ,,f>aday ,,& ,,! ,,fir/ ,,dynamo ,mi*ael ,f>aday1 a ,london newsboy1 ! son ( a blacksmi?1 became ! inv5tor ( ! dynamo1 & prep>$ ! way = ! wond]ful electrical inv5tions ( ! n9ete5? c5tury4 ,he began 8 c>e] z a book-b9d]'s appr5tice1 employ+ 8 sp>e mom5ts 9 read+ ! books he 0 b9d+4 ,"o ( ^! books l$ him to make "s simple exp]im5ts 9 *emi/ry4 ,he also made an electrical ma*9e1 fir/ ) a glass bottle1 & aft]w>d ) a glass cyl9d]4 ,:ile an appr5tice he wrote to 8 "y fri5d1 ,b5jam9 ,abbott3 ,i h lately made a few simple galvanic exp]im5ts1 m]ely to illu/rate to myself ! fir/ pr9ciples ( ! sci5ce4 ,i 0 go+ to ,knight's to obta9 "s nickel1 & be?\ght me t !y _h malleable z9c4 ,i inquir$1 & b\ght "s--h y se5 any yet8 ,! fir/ portion ,i obta9$ 0 9 ! ?9ne/ pieces possible4 ,x 01 !y in=m$ me1 ?9 en\gh = ! electric /ick4 ,i obta9$ x = ! purpose ( =m+ disks ) :i* & copp] to make a little batt]y4 ,! fir/ ,i complet$ conta9$ ! imm5se numb] ( sev5 pairs ( plates666 & ( ! imm5se size ( halfp5ce ea*666666 ,i1 sir1 ,i my own self1 cut out sev5 disks ( ! size ( half p5nies ea*6 ,i1 sir1 cov]$ !m ) sev5 halfp5ce1 & ,i int]pos$ betwe5 !m sev51 or r six1 pieces ( pap] soak$ 9 a solution ( muriate ( soda 7common salt74 ,b laugh no long]1 de> ,a41 r wond] at ! effects ?is trivial p[] produc$4 ,?is t9y batt]y made ( half p5nies ) z9c disks & salt solution w\ld decompose a c]ta9 solution :i* ,f>aday te/$4 ,a l>g] batt]y made ( copp] & z9c disks ) salt solution w\ld decompose wat] f ! ci/]n4 ,:5 ! wires f ! l>g] batt]y 7 put 9 ! ci/]n-wat] he saw a d5se :ite cl\d desc5d+ f ! positive wire1 & bubbles ris+ f ! negative wire4 ,?is action cont9u$ until all ! :ite sub/ance 0 tak5 out ( ! wat]4 ,because ( 8 int]e/ 9 sci5ce1 "y ,f>aday attract$ ! att5tion ( a ,mr4 ,dance1 a memb] ( ! ,royal ,in/itution & a cu/om] ( 8 ma/]1 ,mr4 ,riebau4 ,?r\gh ! k9dness ( ,mr4 ,dance he he>d f\r lectures by ,sir ,humphry ,davy4 ,he took notes on ! lectures1 wrote !m out c>efully1 & add$ draw+s ( ! app>atus4 ,^! notes he s5t to ,davy ) a lett] express+ ! wi% t he might secure employm5t at ! ,royal ,in/itution4 ,9 a %ort "t1 aft] a w>n+ f ,sir ,humphry t he _h bett] /ick to 8 bus9ess ( book-b9d+1 t ,sci5ce is a h>% mi/ress1 8 wi% 0 grant$1 & we f9d him clean+ & c>+ = app>atus 9 ! ,royal ,in/itution & assi/+ ,davy 9 prep>+ = 8 lectures4 ,c\nt ,rum=d ,our /ory n[ takes u back to ! "t ( ! ,am]ican ,revolution4 ,9 ,am]ica1 we f9d a "y man ( n9ete51 ,b5jam9 ,?ompson by "n1 s]v+ z major 9 ! ,second ,regim5t ( ,new ,hamp%ire4 ,! appo9tm5t ( s "y a man z major1 & 8 evid5t hold on ! gov]nor's favor1 ar\s$ ! jeal\sy ( ! old] (fic]s4 ,he 0 accus$ ( be+ unfri5dly to ! cause ( lib]ty4 ,he d5i$ ! *>ge1 & 0 acquitt$ by ! committee ( ! p ( ,concord4 ,a mob ga!r$ r\nd 8 h\se1 b he escap$4 ,driv5 f 8 refuge 9 8 "m's home1 he fl$ to ,engl&1 leav+ 8 wife & *ild4 ,appo9t$ lieut5ant-colonel 9 ! ,briti% ,army1 he return$ to ,am]ica & f\ght aga9/ 8 =m] fri5ds4 ,! w> hav+ end$1 he return$ to ,engl&1 !nce to ! ,cont95t1 int5d+ to take "p 9 an expect$ w> betwe5 ,au/ria & ,turkey4 ,a *ance meet+ ) a ,bav>ian pr9ce1 ,maximilian1 *ang$ ! c\rse ( 8 life4 ,?is pr9ce1 :ile comm&+ on p>ade1 saw ,?ompson among ! spectators m\nt$ on a f9e ,engli% horse1 & address$ him4 ,?ompson in=m$ him t he came f s]v+ 9 ! ,am]ican w>4 ,! pr9ce1 po9t+ to a numb] ( 8 (fic]s1 said3 ,^! g5tlem5 7 9 ! same w>1 b aga9/ y4 ,!y belong$ to ! ,royal ,regim5t ( ,deux ,ponts1 t act$ 9 ,am]ica "u ! ord]s ( ,c\nt ,ro*ambeau4 ,?ompson d9$ ) ! pr9ce & ,fr5* (fic]s4 ,!y conv]s$ ( w> & ! battles 9 :i* !y met4 ,! pr9ce1 attract$ to ! colonel1 induc$ him to pass ?r\gh ,muni*1 & gave him a lett] to 8 uncle1 ! ,elector ( ,bav>ia4 ,x 0 9 ,bav>ia1 ! c\ntry to :i* su* unexpect$ turns ( =tune l$ him1 t 8 greate/ "w 0 done4 ,he ent]$ ! s]vice ( ! ,duke ( ,bav>ia z aide-de-camp4 ,x 0 8 aim :ile 9 ! s]vice ( ! ,bav>ian ,gov]nm5t to bett] ! condition ( ! p4 ,he introduc$ re=ms 9 ! army1 us$ ! soldi]s to rid ! c\ntry ( begg>s & robb]s1 & took /eps to provide = ! infirm & f9d employm5t = ! /rong1 8 motto be+ t p c be/ be made virtu\s :5 fir/ made happy4 ,a ,milit>y ,workh\se 0 op5$ = ! begg>s1 & a ,h\se ( ,indu/ry = ! poor4 ,a ,milit>y ,academy 0 =m$ ) a view to ! free education ( "y p ( tal5t = ! public s]vice4 ,he became absorb$ 9 ! "o aim ( help+ ! poor4 ,s ?or\gh 0 8 devotion to ! p1 & s deeply did he w9 _! affection1 t :5 he 0 dang]\sly ill a multitude ( hundr$s w5t 9 procession to ! *ur* to make public pray]s = 8 recov]y4 ,he saw t ! poor may be help$ by tea*+ !m to save1 & 9 no?+ is !re great] ne$ ( sav+ ?an 9 fuel & heat4 ,9 ! kit*5s ( ! ,milit>y ,academy & ! ,h\se ( ,indu/ry he c>ri$ out a s]ies ( exp]im5ts on ! economy ( fuel1 & succe$$ 9 greatly r$uc+ ! am\nt ( fuel ne$$ = cook+ ! food4 ,he did ?is by us+ a clos$ fireplace1 ! =]unn] ( ! /ove4 ,! clos$ fireplace 0 9 reality a brick /ove1 & 0 a great improvem5t ov] ! op5 *imney fireplaces !n 9 common use4 ,he made ! cov]s ( ! cook+ ut5sils d\ble1 to save ! heat1 = he _h f\nd t heat _c escape ?r\gh conf9$ air4 ,b5jam9 ,?ompson 0 knight$ by ,george ,,iii41 & 9 #agia he 0 made a ,c\nt ( ! ,holy ,roman ,empire1 & is kn[n to ! _w ( sci5ce z ,c\nt ,rum=d4 ,c\nt ,rum=d's ,exp]im5t ) ! ,cannon ,:ile 9 ! s]vice ( ! ,duke ( ,bav>ia1 x became 8 duty to organize ! field artill]y4 ,to provide cannon = ?is purpose1 he erect$ a f\ndry & ma*9e-%ops4 ,be+ al]t = any unusual fact relat+ to heat1 he obs]v$ ! v high temp]ature produc$ by ! bor+ ( ! cannon4 ,he 0 eag] to le>n h[ s mu* heat c\ld be produc$4 ,= ?is purpose he took a cannon 9 ! r\gh1 z x came f ! f\ndry1 fix$ x 9 ! ma*9e us$ = bor+1 & caus$ ! cannon to be turn$ by horses :ile a blunt bor] 0 =c$ aga9/ ! end ( ! cannon4 ,he fir/ te/$ ! temp]ature ( ! metal itself z x turn$4 ,!n he surr\nd$ ! end ( ! cannon ) wat] 9 an oblong box fitt$ wat]-tight 7,fig4 #bj74 ,illu/ration3 ,,fig4 #bj--;,,c\nt ,,rum=d',s ,,exp]im5t ,,) ,,! ,,cannon1 ,,mak+ ,,wat] ,,boil ,,)\t ,,fire ,! horses make ! wat] boil by walk+ ar\nd ! track2 ! "w ! horses d is *ang$ into heat by ! friction ( ! drill4 ,! cannon _h be5 turn+ b a %ort "t :5 he f\nd by putt+ 8 h& 9 ! wat] t heat _h be5 produc$4 ,9 two h\rs & ?irty m9utes ! wat] actually boil$4 ,a/oni%m5t 0 express$ 9 ! faces ( ! by/&]s on see+ s l>ge a quantity ( wat] heat$ & actually made to boil )\t any fire4 ,heat1 ,c\nt ,rum=d said2 may ?us be produc$ m]ely by ! /r5g? ( a horse1 &1 9 case ( necessity1 ?is heat might be us$ 9 cook+ victuals4 ,b no circum/ance c be imag9$ 9 :i* !re is any advantage 9 ?is me?od ( procur+ heat1 = m heat might be obta9$ by burn+ ! fodd] :i* ! horse w\ld eat4 ,! mean+ ( ?is la/ rem>k 0 n und]/ood until ! "t ( ,rob]t ,may]1 ab\t fifty ye>s lat]4 ,rum=d _h f\nd t ! "w ( a horse c produce heat1 & heat1 9 a /eam-eng9e1 c d ! "w ( a horse4 ,?us surely1 ?\gh sl[ly1 m5 7 le>n+ ( ! =ces t move ! _w & d man's bidd+4 ,c\nt ,rum=d1 true to 8 adopt$ l&1 return$ to ,london & became ! f\nd] ( ! ,royal ,in/itution 9 :i* ,f>aday & 8 successors h a*iev$ su* m>vell\s results4 ,he believ$ t ! poor c be help$ 9 no bett] way ?an by giv+ !m k1 s t !y c bett] _! own condition4 ,= ?is purpose he f\nd$ ! ,royal ,in/itution4 ,"h he int5d$ t m5 skill$ 9 discov]y %\ld ga9 new k t w\ld add to ! com=t & happ9ess ( ! p4 ,davy ,9 ! ,engli% coal-fields _m accid5ts due to ! burn+ ( fire-damp _h occurr$4 ,fire-damp is caus$ by gas issu+ f ! coal4 ,on ! approa* ( a flame ?is gas cat*es fire1 & z x burns x produces a viol5t w9d1 driv+ ! flame be=e x ?r\gh ! m9e4 ,m9]s 7 scor*$ to dea?1 suffocat$1 or buri$ "u ru9s f ! ro(4 ,hundr$s ( m9]s _h be5 kill$4 ,no means ( light+ ! m9es 9 safety _h be5 devis$4 ,sir ,humphry ,davy1 ,pr(essor ( ,*emi/ry 9 ! ,royal ,in/itution1 0 appeal$ to4 ,aft] _m exp]im5ts he devis$ a safe lamp1 :i* 0 a common m9]'s lamp enclos$ 9 a wire gauze4 ,?is prov$ a p]fect protection f fire-damp1 & ! ,davy safety lamp has be5 us$ by m9]s ! _w ov] = m ?an a c5tury4 ,b ,davy's be/ "w 0 ) ! electric batt]y4 ,"s ( ! facts mo/ famili> to u 7 discov]$ by him4 ,volta _h cont5d$ t ! contact ( ! metals 9 a batt]y produces a curr5t1 t ! liquid m]ely c>ries ! electricity f "o metal plate to ! o!r4 ,b ,davy prov$ t !re c be no curr5t )\t *emical action4 ,:5ev] we put two metals 9 an acid or o!r solution t w dissolve "o metal fa/] ?an ! o!r1 & connect ! metals ) a wire1 an electric curr5t is produc$4 ,if we use wat] ) silv] & gold1 !re is no curr5t1 because wat] w n dissolve ei!r ! silv] or ! gold4 ,davy discov]$ ! metal1 potassium1 by means ( 8 electric batt]y4 ,potassium is f\nd 9 common pota% & saltpetre1 &1 :5 sep>at$1 is a v s(t metal4 ,! newly discov]$ metal ar\s$ great int]e/ 9 o!r c\ntries4 ,:5 ,napoleon he>d ( x1 he inquir$ impetu\sly h[ x happ5$ ! discov]y _h n be5 made 9 ,france4 ,on be+ told t 9 ,france !re _h n be5 made an electric batt]y ( suffici5t p[]1 he exclaim$3 ,!n let "o be in/antly made )\t reg>d to co/ or labor4 ,8 comm& 0 obey$1 & he 0 call$ to witness ! action ( ! new batt]y4 ,be=e any "o c\ld int]f]e he plac$ ! ends ( ! wires "u 8 tongue & receiv$ a %ock t ne>ly depriv$ him ( s5sation4 ,on recov]+ he left ! laboratory )\t a ^w1 & 0 nev] aft]w>d he>d to ref] to ! subject4 ,davy made _m great discov]ies1 b ! greate/ 0 8 discov]y ( ,f>aday4 99 99 99 99 99 ,a j\rney on ! ,cont95t ) ,davy 0 an ev5t 9 ! life ( ,f>aday1 :o up to t "t _h nev] to 8 own recollection travell$ twelve miles f ,london4 ,on ?is j\rney he met ,volta1 :om he describes z an hale eld]ly man1 v free 9 conv]sation4 ,he visit$ ! ,academy del ,cim5to1 9 ,flor5ce1 & wrote3 ,"h 0 mu* to excite int]e/2 9 "o place 0 ,galileo's fir/ telescope1 t ) :i* he discov]$ ,jupit]'s satellites4 ,x 0 a simple tube ( wood & pap]1 ab\t ?ree & a half feet long1 ) a l5s at ea* end4 ,!re 0 also ! fir/ l5s :i* ,galileo made4 ,x 0 set 9 a v pretty frame ( brass1 ) an inscription 9 ,lat9 on x4 ,f>aday cross$ ! ,alps & ! ,ap5n9es1 climb$ ,vesuvius1 visit$ ,rome1 & saw a gl[-worm4 ,! la/ he ?\ght z wond]ful z ! fir/4 ,%ortly aft] 8 return to ,london he fell 9 love4 ,n[1 ,f>aday _h det]m9$ t he w\ld n be conqu]$ by ! ma/] passion4 ,9 fact1 he _h writt5 v>i\s asp]sions on love1 ( :i* ! foll[+ is a sample3 ,:at is ! pe/ & plague ( human life8 ,& :at ! curse t (t5 br+s a wife8 ',tis ,love4 ,:at is't directs ! madman's hot int5t1 ,= :i* a dunce is fully compet5t8 ,:at's t ! wise man always /rives to %un1 ,?\gh /ill x ev] o'er ! _w has run4 ',tis ,love4 ,b he reckon$ n ) 8 own he>t4 ,x is n long until we f9d him writ+ to ,miss ,s>ah ,b>n>d1 a bright girl ( tw5ty-"o3 ,y h conv]t$ me f "o errone\s way1 let me hope y w attempt to correct :at o!rs are wrong4444 ,aga9 & aga9 ,i attempt to say :at ,i feel1 b ,i _c4 ,let me1 h[ev]1 claim n to be ! selfi% be+ t wi%es to b5d y\r affections = 8 own sake only4 ,9 :atev] way ,i c m9i/] to y\r happ9ess1 ei!r by close att5tion or by abs5ce1 x %all be done4 ,d n injure me by )draw+ y\r fri5d%ip or puni% me = aim+ to be m ?an a fri5d by mak+ me less4 ,!y 7 m>ri$ & liv$ 9 rooms at ! ,royal ,in/itution4 ,no poet ev] lov$ m t5d]ly ?an ,f>aday4 ,truly1 sci5ce does n dry up ! he>t's blood4 ,at ! age ( sev5ty-"o he wrote to 8 wife :ile abs5t f home = a few days3 ,rememb] me2 ,i ?9k z mu* ( y z is good = ei!r y or me4 ,we _c well d )\t ea* o!r4 ,b we love ) a /rong hope ( love cont9u+ ev]4 ,f>aday's ,electrical ,discov]ies ,n[ we %all turn to ,f>aday's electrical discov]ies & inv5tions4 ,m5 _h long kn[n t1 9 h\ses t h be5 /ruck by lightn+1 /eel objects su* z knives & ne$les are sometimes f\nd to be magnetiz$4 ,%ips /ruck by lightn+ _h f\nd _! compass-ne$les po9t+ s\? in/ead ( nor?1 or w&]+ 9 direction & wor?less4 ,m5 _h wond]$ h[ an electrical dis*>ge c\ld magnetize /eel4 ,!y _h tri$ ! sp>k ( ! electrical ma*9e ) no def9ite result4 ,frankl91 9 8 exp]im5t ( magnetiz+ a /eel ne$le by pass+ an electric sp>k ?r\gh x1 c\ld n tell be=e ! sp>k 0 pass$ ?r\gh ! ne$le :i* end w\ld be ! nor? pole4 ,!re 0 no seem+ connection betwe5 ! direction ( ! electric dis*>ge & ! pol>ity ( ! ne$le4 ,aft] ! discov]y ( ! electric batt]y1 m5 tri$ to discov] a relation betwe5 ! electric curr5t & magnetism4 ,o]/$ & ,electromagnetism ,! fir/ success 9 ?is direction 0 a*iev$ by ,hans ,*ri/ian ,o]/$1 a native ( ,d5m>k4 ,pov]ty impell$ 8 fa!r to take him f s*ool at ! age ( twelve & place him 9 an apo!c>y's %op4 ,! boy1 ,hans1 f\nd delight 9 ! *emical "w ( ! apo!c>y4 ,8 eag]ness to le>n & ! pressure ( pov]ty l$ him to neglect ! usual sports ( boyhood & devote 8 leisure "t to read+ & /udy4 ,aga9 he ent]$ s*ool1 &1 ?\gh pay+ 8 way by 8 own "w1 he graduat$ ) honor f ! ,univ]sity ( ,cop5hag54 ,he 0 appo9t$ ,pr(essor ( ,physics 9 ?is univ]sity1 & "h he made 8 fir/ great discov]y 9 electromagnetism4 ,aft] work+ = sev5 ye>s to discov] a relation betwe5 curr5t electricity & magnetism1 he made a discov]y :i* prov$ to be ! fir/ /ep 9 ! inv5tion ( ! dynamo4 ,he 0 us+ a magnetic compass1 :i* is a small magnetic ne$le balanc$ on a /eel po9t4 ,! ne$le po9ts ne>ly nor? & s\? unless di/urb$ by a magnet br\ght ne> x4 ,he _h tri$ to f9d if a wire ?r\gh :i* a curr5t is fl[+ w\ld di/urb ! compass z a magnet does4 ,he _h tri$ plac+ ! wire ea/ & we/1 ?9k+ ! compass-ne$le w\ld foll[ ! wire z x does a magnet4 ,"o day1 :ile lectur+ to 8 /ud5ts1 x occurr$ to him = ! fir/ "t to place ! wire nor? & s\? ov] ! compass-ne$le4 ,he 0 surpris$ & p]plex$ z he did s to see ! ne$le sw+ r\nd & po9t ne>ly ea/ & we/ 7,fig4 #ba74 ,on rev]s+ ! curr5t ! ne$le swung 9 ! opposite direction4 ,he _h discov]$ ! magnetic action ( an electric curr5t4 ,x 0 le>n$ soon aft]w>d t a coil ( wire ) an electric curr5t fl[+ ?r\gh x acts l a magnet1 & t a curr5t fl[+ ar\nd a b> ( s(t iron makes ! iron a magnet 7,figs4 #bb & #bc74 ,illu/ration3 ,,fig4 #ba--,,o]/$',s ,,exp]im5t ,an electric curr5t fl[+ ov] ! compass-ne$le t[>d ! nor? causes ! ne$le to turn until x po9ts ne>ly we/4 ,by p]mission ( ,joseph ,g4 ,bran*4 ,illu/ration3 ,,fig4 #bb4--;,a ,,coil ,,) ,a ,,curr5t ,,fl[+ ,,?r\gh ,,x ,,acts ,,l ,a ,,magnet ,! coil is pick+ up iron fil+s4 ,illu/ration3 ,,fig4 #bc--;,a ,,b> ,,( ,,s(t ,,iron ,,) ,a ,,curr5t ,,fl[+ ,,ar\nd ,,x ,,becomes ,a ,,magnet ,ampre ,! news ( ,o]/$'s discov]y ar\s$ great int]e/ ?r\gh\t ,europe4 ,soon aft] its ann\ncem5t 9 ,france1 ,&r ,m>ie ,ampre made a discov]y ( equal importance4 ,o]/$ _h discov]$ electromagnetism4 ,ampre discov]$ electrical p[] or motion produc$ by an electrical curr5t4 ,! y\? ( ,ampre 0 pass$ amid ! /ormy sc5es ( ! ,fr5* ,revolution4 ,8 fa!r _h mov$ f 8 c\ntry home to ,lyons & become a ju/ice ( ! peace4 ,9 ! de/ruction ( ! city ( ,lyons dur+ ! ,reign ( ,t]ror he lo/ 8 head "u ! guillot9e4 ,! bl[ 0 too great = ,ampre1 !n a y\? ( eighte54 ,he _h be5 a precoci\s *ild1 advanc$ beyond 8 ye>s 9 all ! /udies ( ! s*ools4 ,b n[ 8 /rong m9d fail$4 ,= a ye> he w&]$ ab\t me*anically pil+ up heaps ( s& or gaz+ ^u ! sky4 ,!n 8 m5tal p[] return$1 & he took up ) eag]ness ! /udy ( botany & poetry4 ,he became a pr(essor 9 ! ,polyte*nic ,s*ool 9 ,p>is1 & x 0 :ile tea*+ 9 ?is s*ool t he made 8 great discov]ies4 ,he f\nd t two coils ( wire c be made to attract or repel ea* o!r by an electric curr5t4 ,if ! curr5t fl[s ?r\gh ! two coils 9 ! same direction1 !y attract ea* o!r 7,fig4 #bd74 ,if ! curr5t fl[s 9 opposite directions ?r\gh ! coils1 !y repel ea* o!r 7,fig4 #be74 ,?is is n v /range to u1 = we "k t a coil ) a curr5t fl[+ ?r\gh x acts j l a magnet4 ,ea* coil !n has a nor? pole & a s\? pole4 ,if ! coils are plac$ s t ! two nor? poles or ! two s\? poles are toge!r1 !y w repel ea* o!r4 ,if ! nor? pole ( "o coil is ne> ! s\? pole ( ! o!r1 !y w attract ea* o!r4 ,illu/ration3 ,,fig4 #bd--,,two ,,coils ,,) ,,curr5ts ,,fl[+ ,,9 ,,same ,,direction ,,attract ,,ea* ,,o!r ,illu/ration3 ,,fig4 #be--,,two ,,coils ,,) ,,curr5ts ,,fl[+ ,,9 ,,opposite ,,directions ,,repel ,,ea* ,,o!r ,ampre believ$ t electric curr5ts are fl[+ ar\nd )9 ! e>?1 & t ! e>? has a nor? & a s\? magnetic pole = ! same reason t a coil ( wire has magnetic poles2 t ^! poles are caus$ by ! curr5ts fl[+ ar\nd 9 ! e>? j z ! poles ( ! coil are caus$ by ! curr5t fl[+ ar\nd 9 ! coil4 ,we d honor to ! "n ( ,ampre :5ev] we measure an electric curr5t1 = electric curr5ts are measur$ 9 amp]es4 ,arago ,ano!r important discov]y 0 made by a "y ,fr5*man1 ,franois ,arago1 )9 a ye> ( ! "t :5 ,o]/$ & ,ampre made _! discov]ies4 ,! ?ree great discov]ies ( ^! m5 7 made 9 ! ye>s #ahai & #ahbj4 ,! y\? ( ,arago 0 full ( adv5ture4 ,he _h assi/$ 9 mak+ a survey 9 ! ,pyr5ees1 ! haunt ( d>+ robb]-b&s4 ,twice 9 8 cab9 he 0 visit$ by a *ief ( a robb]-b& :o claim$ to be a cu/om-h\se gu>d4 ,on ! second visit he said to ! robb]3 ,y\r position is p]fectly kn[n to me4 ,i "k t y are n a cu/om-h\se gu>d4 ,i h le>n$ t y are ! *ief ( ! robb]s ( ! c\ntry4 ,tell me :e!r ,i h any?+ to fe> f y\r conf$]ates4 ,! robb] repli$3 ,! idea ( robb+ y did occur to u2 b1 on ! day t we mole/$ an envoy f ! ,fr5*1 !y w\ld direct aga9/ u sev]al regim5ts ( soldi]s1 & we are n s /rong z !y4 ,all[ me to add t ! gratitude :i* ,i owe y = ! night's %elt] is y\r sure/ gu>antee4 ,at a lat] "t1 :5 w> betwe5 ,spa9 & ,france 0 ?reat5$1 he 0 accus$ ( be+ a spy1 & a mob 0 =m$ to put him out ( ! way4 ,he escap$ 9 disguise ?r\gh ! mid/ ( ! mob & bo>d$ a ,spani% %ip4 ,he 0 c>ri$ to ,morocco1 ran ! gantlet ( blood?ir/y ,mussulmans 9 ,algi]s1 escap$ dea? by a hair's-bread?1 & ?r\gh x all clung to ! pap]s :i* record$ ! results ( ! survey 9 ! m\nta9s1 & deliv]$ !m 9 safety to ! (fice ( ! ,bureau ( ,longitude 9 ,p>is4 ,arago made a discov]y :i*1 ) ^? ( ,o]/$ & ,ampre1 prep>$ ! way = ,f>aday's great electrical discov]ies & ! inv5tion ( ! dynamo4 ,he f\nd t a plate ( copp] :irl+ above or bel[ a magnetic ne$le w draw ! ne$le aft] x 7,fig4 #bf74 ,he c\ld make ! spe$ ( ! :irl+ copp] plate s great t ! ne$le w\ld :irl rapidly1 foll[+ ! copp] plate4 ,f>aday 0 ! fir/ to expla9 ,arago's exp]im5t4 ,illu/ration3 ,,fig4 #bf--;,,arago',s ,,exp]im5t ,:5 ! copp] plate :irls ! magnet :irls also1 ?\gh x does n t\* ! copp] plate4 ,f>aday's ,fir/ ,electric ,motor ,f>aday's fir/ electrical discov]y 0 made soon aft] t ( ,arago4 ,o]/$ _h prov5 t an electric curr5t acts on a magnet4 ,! magnet turns at "r angles to ! wire4 ,f>aday saw t ?is is because ! nor? pole ( ! magnet tries to g r\nd ! wire 9 "o direction1 & ! s\? pole tries to g r\nd 9 ! opposite direction4 ,he plac$ a magnet on end 9 a di% ( m]cury1 ) "o pole ( ! magnet above ! m]cury1 & f\nd t ! magnet w\ld sp9 r\nd a wire c>ry+ a curr5t4 ,:5 ! curr5t acts on "o pole ( ! magnet only1 ! magnet sp9s r\nd ! wire 7,fig4 #bg74 ,s ,f>aday's fir/ electrical discov]y prep>$ ! way = ! electric motor4 ,illu/ration3 ,,fig4 #bg--,,"o ,,pole ,,( ,a ,,magnet ,,sp9s ,,r\nd ,a ,,wire ,,?r\gh ,,:i* ,,an ,,electric ,,curr5t ,,fl[s ,an ,electric ,curr5t ,produc$ by a ,magnet ,he _h writt5 9 8 note-book3 ,conv]t magnetism into electricity4 ,an electric curr5t w\ld magnetize iron4 ,w\ld n a magnet produce an electric curr5t8 ,?is 0 8 problem4 ,he connect$ a coil ( wire to an in/rum5t t w\ld tell :5 a curr5t 0 fl[+1 & plac$ a magnet 9 ! coil4 ,o!rs _h claim$1 & ,f>aday at fir/ believ$1 t a curr5t w\ld fl[ :ile ! magnet lay quiet )9 ! coil4 ,b ,f>aday 0 al]t = ! unexpect$1 & ! unexpect$ happ5$4 ,= an in/ant1 z he ?ru/ ! magnet into ! coil1 8 in/rum5t %[$ t a curr5t 0 fl[+4 ,aga91 z he drew ! magnet quickly f ! coil1 a curr5t fl[$1 b 9 ! opposite direction 7,fig4 #bh74 ,f ?is simple exp]im5t has gr[n ! alt]nat+-curr5t ma*9]y by :i* ! p[] ( ,niag>a is made to light cities & drive electric c>s at a di/ance ( _m miles4 ,illu/ration3 ,,fig4 #bh--,,:5 ,a ,,magnet ,,is ,,?ru/ ,,into ,a ,,coil ,,( ,,wire ,,x ,,causes ,a ,,curr5t ,,to ,,fl[ ,,9 ,,! ,,coil1 ,,b ,,! ,,curr5t ,,fl[s ,,only ,,:ile ,,! ,,magnet ,,is ,,mov+ ,draw+ reproduc$ by p]mission ( ,joseph ,g4 ,bran*4 ,a fri5d ( ,f>aday1 on le>n+ ( ?is discov]y1 wrote ! foll[+ impromptu l9es3 ,ar\nd ! magnet ,f>aday ,0 sure t ,volta's lightn+s play4 ,b h[ to draw !m f ! wire8 ,he took a lesson f ! he>t3 ',tis :5 we meet1 'tis :5 we "p1 ,breaks =? ! electric fire4 ,a magnet w produce an electric curr5t 9 a wire1 b only :5 ! magnet or ! wire is 9 motion4 ,detect+ & ,measur+ an ,electric ,curr5t ,! in/rum5t :i* ,f>aday us$ to detect a curr5t 0 d]iv$ f ,o]/$'s exp]im5t4 ,:5 a curr5t fl[s 9 a nor?-&-s\? direction ov] a compass-ne$le1 ! ne$le sw+s r\nd4 ,:5 ! curr5t /ops fl[+ ! ne$le sw+s back to ! nor?-&-s\? position4 ,! effect on ! ne$le is /rong] if ! curr5t fl[s ?r\gh a coil ( wire & ! coil is plac$ 9 a nor?-&-s\? position ar\nd ! ne$le 7,fig4 #bi74 ,! /rong] ! curr5t fl[+ ?r\gh ! coil ! f>!r ! ne$le w turn f ! nor?-&-s\? position4 ,illu/ration3 ,,fig4 #bi--;,a ,,coil ,,( ,,wire ,,ar\nd ,a ,,compass-,,ne$le ,! ne$le tells :5 a curr5t is fl[+1 & h[ /rong ! curr5t is4 ,! coil & ! ne$le toge!r are call$ a galvanomet]1 & may be us$ to tell :5 a curr5t is fl[+1 & also to indicate ! /r5g? ( ! curr5t4 ,an ,electric ,curr5t ,produc$ by ! ,magnetic ,field ( ,ano!r ,curr5t ,f>aday _h f\nd t a curr5t fl[+ ar\nd a piece ( iron w make ! iron a magnet1 & t a magnet 9 motion w cause a curr5t to fl[ 9 a wire4 ,x seem$ to him t a second wire plac$ ne> ! fir/ %\ld h a curr5t produc$ 9 x )\t ! pres5ce ( iron4 ,he w\nd two coils ( copp] wire ^u ! same wood5 spool4 ,! wire ( ! two coils he sep>at$ ) tw9e & calico4 ,"o coil 0 connect$ ) a galvanomet]1 ! o!r ) a batt]y ( t5 cells1 yet n ! slighte/ turn+ ( ! ne$le c\ld be obs]v$4 ,b he 0 n det]r$ by "o failure4 ,he rais$ 8 batt]y f t5 cells to "o hundr$ cells1 b )\t avail4 ,! curr5t fl[$ calmly ?r\gh ! batt]y wire )\t produc+1 dur+ its fl[1 any effect ^u ! galvanomet]4 ,dur+ its fl[ 0 ! "t :5 an effect 0 expect$4 ,aga9 ! unexpect$ happ5$4 ,at ! in/ant ( mak+ contact ) ! batt]y !re 0 a slight movem5t ( ! ne$le4 ,:5 ! contact 0 brok51 ano!r slight movem5t1 b 9 ! opposite direction to ! fir/ 7,fig4 #cj74 ,! curr5t 9 "o wire caus$ a curr5t to fl[ 9 ! o!r1 b ! curr5t 9 ! second wire cont9u$ = an in/ant only at ! mak+ & break+ ( ! contact ) ! batt]y4 ,?is 0 ! beg9n+ ( ! induction-coil us$ to-day 9 wireless telegraphy4 ,illu/ration3 ,,fig4 #cj--;,,f>aday',s ,,induction-,,coil ,/>t+ & /opp+ ! batt]y curr5t 9 ! prim>y coil causes a *ang+ magnetic field1 & ?is causes a curr5t to fl[ 9 ! second>y coil4 ,draw+ reproduc$ by p]mission ( ,joseph ,g4 ,bran*4 ,:at 0 ! secret ( x8 ,simply ?is3 t a curr5t 9 "o wire w cause a curr5t to fl[ 9 ano!r wire ne> x1 b only :ile ! curr5t 9 ! fir/ wire is *ang+4 ,t is1 at ! in/ant :5 ! fir/ wire is connect$ to ! batt]y1 or its connection brok51 a curr5t is induc$ 9 ! second wire4 ,!re is no batt]y or o!r s\rce ( curr5t connect$ to ! second wire2 b a curr5t fl[s 9 ?is wire because x is ne> a wire 9 :i* a curr5t is rapidly />t+ & /opp+4 ,:5 ^! two wires are w\nd 9 coils1 toge!r !y =m an induction-coil4 ,! wire :i* we h call$ ! fir/ wire =ms ! prim>y coil1 & ! "o we h call$ ! second wire =ms ! second>y coil4 ,by repeat$ly mak+ & break+ ! circuit 9 ! prim>y coil we get an alt]nat+ curr5t 9 ! second>y coil4 ,fig4 #ca is f a photograph ( "s ( ! coils actually us$ by ,f>aday4 ,illu/ration3 ,,fig4 #ca--;,,hi/orical ,,app>atus ,,( ,,f>aday ,,9 ,,! ,,royal ,,in/itution ,"s ( ,f>aday's trans=m] coils are %[n "h4 ,! in/rum5t on ! left 9 a glass case is 8 galvanomet]4 ,f>aday's ,dynamo ,to inv5t a new electrical ma*9e 0 ,f>aday's next aim4 ,arago's disk ( copp] :irl+ ne> a magnet _h a curr5t induc$ 9 x1 s ,f>aday ?\ght4 ,x 0 ! action ( ?is induc$ curr5t :i* caus$ ! magnet to foll[ ! :irl+ disk4 ,c\ld ! curr5t 9 ,arago's disk be collect$ & caus$ to fl[ ?r\gh a wire8 ,he plac$ a copp] disk betwe5 ! poles ( a magnet4 ,"o galvanomet] wire pass$ ar\nd ! axis ( ! disk1 ! o!r he held 9 contact ) ! edge4 ,he :irl$ ! disk4 ,! galvanomet] ne$le mov$4 ,a curr5t 0 fl[+ 9 ! disk z x :irl$4 ,! curr5t f ! :irl+ disk fl[$ ?r\gh ! galvanomet]4 ,f>aday _h discov]$ ! dynamo 7,fig4 #cb74 ,illu/ration3 ,,fig4 #cb--;,,f>aday',s ,,fir/ ,,dynamo ,a curr5t fl[s 9 ! copp] disk z x :irls betwe5 ! poles ( ! magnet4 ,by p]mission ( ,joseph ,g4 ,bran*4 ,all ?is "w occupi$ b t5 days 9 ! autumn ( #ahca1 ?\gh ye>s ( prep>ation _h gone be=e4 ,9 ^! t5 days ! f\ndation 0 laid = ! induction-coil1 mod]n dynamo-electric ma*9]y1 & electric light+4 ,fig4 #cc %[s ! laboratory 9 :i* ,f>aday did ?is "w4 ,illu/ration3 ,,fig4 #cc--;,,f>aday',s ,,laboratory1 ,,:]e ,,! ,,fir/ ,,dynamo ,,0 ,,made ,f ! wat]-color draw+ by ,miss ,h>riet ,moore4 ,f>aday cont9u$ to explore ! field op5$ up be=e him4 ,9 "o exp]im5t two small p5cils ( *>coal lightly t\*+ 7 connect$ to ! ends ( a second>y coil4 ,a sp>k pass$ betwe5 ! *>coal po9ts :5 ! prim>y circuit 0 clos$4 ,?is 0 ! fir/ trans=m] produc+ a t9y electric light 7,fig4 #cd74 ,illu/ration3 ,,fig4 #cd--,,! ,,fir/ ,,trans=m] ,f>aday discov]$ ! induction-coil1 ! dynamo1 & ! trans=m]1 & he %[$ t1 9 ea* ( ^!1 x is magnetism :i* produces ! electric curr5t4 ,he _h discov]$ ! secret :5 he obta9$ a curr5t by ?ru/+ a magnet into a coil ( wire4 ,! space ab\t a magnet 9 :i* ! magnet w attract iron he call$ ! magnetic field 7,figs4 #ce & #cf74 ,9 e case ( magnetism caus+ an electric curr5t to fl[ 9 a coil ( wire1 ! coil is 9 a magnetic field1 & ! magnetic field is *ang+--t is1 ! magnetic field is made alt]nately /rong] & weak]1 or ! coil moves across ! magnetic field4 ,! po9t is t magnetism at re/ w n produce an electric curr5t4 ,!re mu/ be a *ang+ magnetic field or motion4 ,9 ,f>aday's dynamo a copp] disk :irl$ betwe5 ! poles ( a magnet & ! :irl+ ( ! disk 9 ! magnetic field caus$ an electric curr5t4 ,9 ! mod]n dynamo x is ! :irl+ ( a coil ( wire 9 a magnetic field t causes a curr5t to fl[4 ,9 ! induction-coil x is ! *ange 9 ! magnetic field t causes a curr5t to fl[ 9 ! second>y coil4 ,a coil ( wire ) an electric curr5t fl[+ ?r\gh x w attract iron l a magnet4 ,! prim>y coil ) a curr5t f a batt]y fl[+ ?r\gh x acts 9 all respects l a magnet2 b z soon z ! curr5t ceases to fl[ ! magnetic field disappe>s--! coil is no long] a magnet4 ,:5 we make & break ! connection betwe5 ! prim>y coil & ! batt]y1 !n1 we repeat$ly make & de/roy ! magnetic field1 & ?is *ang+ magnetic field causes a curr5t to fl[ 9 ! second>y coil4 ,! induction-coil is "o =m ( trans=m]4 ,we %all see lat] h[ ! dynamo & ! trans=m] develop$ 9 ! n9ete5? c5tury4 ,illu/ration3 ,,fig4 #ce--,,! ,,magnetic ,,field ,,is ,,! ,,space ,,ar\nd ,a ,,magnet ,,9 ,,:i* ,,x ,,w ,,attract ,,iron ,! iron fil+s ov] ! magnet arrange !mselves along ! l9es ( =ce4 ,illu/ration3 ,,fig4 #cf--,,magnetic ,,field ,,( ,a ,,horse%oe ,,magnet ,:5 a boy1 ,f>aday _h pass$ ! curr5t f 8 little batt]y ?r\gh a j> ( ci/]n-wat]1 & saw 9 ! wat] a d5se :ite cl\d desc5d+ f ! positive wire1 & bubbles aris+ f ! negative wire4 ,some?+ 0 be+ tak5 out ( ! wat] by ! electric curr5t4 ,:5 he tri$ ! exp]im5t lat] 9 8 laboratory1 he f\nd t1 :5ev] an electric curr5t is pass$ ?r\gh wat]1 bubbles ( two gases1 oxyg5 & hydrog51 rise ?r\gh ! wat]4 ,he f\nd t if ! curr5t is made /rong] ! bubbles are =m$ fa/]4 ,! wat] 9 "t disappe>s1 = x has be5 *ang$ or decompos$ into ! two gases4 ,x 0 ! curr5t f a batt]y t w\ld decompose wat]4 ,! electricity f ! electrical ma*9e w\ld d o!r ?+s t he _h nev] se5 a batt]y curr5t d4 ,d ! batt]y & ! electrical ma*9e produce diff]5t k9ds ( electricity1 or is electricity "o & ! same 9 :atev] way x is produc$8 ,?is 0 ! qu]y t tr\bl$ him4 ,! answ] to ?is "q _h be5 s unc]ta9 t ! effect ( ! voltaic batt]y _h be5 t]m$ galvanism1 :ile t ( ! friction ma*9e reta9$ ! "n electricity4 ,f>aday tri$ _m exp]im5ts 9 se>*+ = an answ] to ?is "q4 ,he f\nd t ! electricity ( ! ma*9e w produce ! same effect z t ( a batt]y if ! ma*9e is compell$ to dis*>ge sl[ly4 ,an electrical ma*9e or a batt]y ( ,leyd5 j>s c be made to give out an electric curr5t1 & ?is curr5t w affect a magnetic ne$le 9 ! same way t a batt]y curr5t w4 ,x w magnetize /eel4 ,if pass$ ?r\gh wat]1 x w decompose ! wat] into ! two gases oxyg5 & hydrog54 ,9 %ort1 a curr5t f an electrical ma*9e or a ,leyd5 j> w d ev]y?+ t a curr5t f an electric batt]y w d4 ,f>aday caus$ ! ,leyd5 j> to give a curr5t in/ead ( a sp>k by connect+ ! two metal coat+s ) a wet /r+4 ,on ! o!r h&1 ! dis*>ge f a p[]ful electric batt]y w produce a sp>k & affect ! human n]ves 9 ! same way z ! dis*>ge f ! electrical ma*9e4 ,! same effects may be obta9$ f "o z f ! o!r4 ,9 ! dis*>ge f ! ma*9e1 a small quantity ( electricity is dis*>g$ "u high pressure1 z wat] may be =c$ ?r\gh a small op5+ by v high pressure4 ,! voltaic cell1 on ! o!r h&1 furni%es a l>ge quantity ( electricity at l[ pressure1 z a /reet may be flood$ by a brok5 wat]-ma9 ?\gh ! pressure is l[4 ,9 fact1 ! quantity ( electricity requir$ to decompose a gra9 ( wat] is equal to t dis*>g$ 9 a /roke ( lightn+1 :ile ! action ( a dilute acid on ! "o-hundr$? "p ( an ounce ( z9c 9 a batt]y yields electricity suffici5t = a p[]ful ?und]-/orm4 ,_m te/s 7 made1 & ! result 0 a conv9c+ pro( t electricity is ! same :atev] its s\rce1 ! diff]5t effects be+ due to diff]5ce 9 pressure & quantity4 ,b 9 no case1 said ,f>aday1 n ev5 9 ^? ( ! electric eel & torp$o1 is !re a production ( electric p[] )\t some?+ be+ us$ up to supply x4 ,f>aday's pr(essional "w w\ld h made him weal?y4 ,9 "o ye> he made #ajjj 7#ejjj71 & ! am\nt w\ld h increas$ _h he sold 8 s]vices at _! m>ket value4 ,b !n !re w\ld h be5 no ,f>aday ! discov]]4 ,! _w w\ld h _h to wait1 no "o kn[s h[ long1 = ! lay+ ( ! f\ndations ( electrical indu/ries4 ,he *ose to give up weal? = ! sake ( discov]y4 ,he gave up pr(essional "w ) ! exception ( sci5tific advis] to ,tr9ity ,h\se1 ! body :i* has *>ge ( ,great ,brita9's ligh?\se s]vice4 ,nor did he c>ry 8 discov]ies to ! po9t ( practical application4 ,z soon z he discov]$ "o pr9ciple1 he set out 9 pursuit ( o!rs1 leav+ ! practical application to ! future4 ,f>aday lov$ ! beauty ( nature4 ,! sunset he call$ ! sc5]y ( heav54 ,he saw ! beauty ( electricity1 :i* he said lies n 9 its my/]y1 b 9 ! fact t x is "u law & )9 ! control ( ! human intellect4 ,a ,wond]ful ,law ( ,nature ,n long aft] ,f>aday made 8 fir/ dynamo1 ,rob]t ,may]1 a physician f ,g]many1 0 mak+ a voyage to ! ,ea/ ,indies :i* prov$ to be a voyage ( discov]y4 ,he _h sail$ z ! %ip's physician1 & aft] "s mon?s an epidemic broke out among ! %ip's company4 ,9 8 treatm5t he drew blood f ! ve9s ( ! arms4 ,he 0 />tl$ to see bright-r$ blood issue f ! ve9s4 ,he might almo/ h believ$ t he _h op5$ an art]y by mi/ake4 ,x 0 soon expla9$ to him by a physician :o _h liv$ long 9 ! tropics t ! blood 9 ! ve9s ( ! natives1 & ( =eign]s z well1 9 ! tropics is ( ne>ly ! same color z art]ial blood4 ,9 cold] climates ! v5\s blood is mu* d>k] ?an ! art]ial4 ,he reason$ ^u ?is curi\s fact = "s "t1 & came to ! conclusion t ! human body does n make heat out ( no?+1 b consumes fuel4 ,! fuel is consum$ 9 ! blood1 & !re ! heat is produc$4 ,9 ! tropics less heat is ne$$1 less fuel is consum$1 & !re=e !re is less *ange 9 ! color ( ! blood4 ,:5 a man works he uses up fuel4 ,if a blacksmi? heats a piece ( iron by hamm]+1 ! heat giv5 to ! iron & ! heat produc$ 9 8 body are toge!r equal to ! heat ( ! fuel consum$ 9 8 blood4 ,! "w a man does1 z well z ! heat ( 8 body1 comes f ! burn+ ( ! fuel 9 8 blood4 ,:at is true ( a man is true ( an eng9e4 ,! "w ! eng9e does1 z well z ! heat x produces1 comes f ! heat ( ! fuel 9 ! furnace4 ,may] f\nd t "o hundr$ p\nds ( coal 9 a good work+ eng9e produces ! same am\nt ( heat z n9ety-five p\nds 9 an eng9e t is n work+4 ,9 ! work+ eng9e ! heat ( ! five p\nds ( coal is us$ up 9 ! "w ( runn+ ! eng9e1 & !re=e does n heat ! eng9e4 ,heat t is us$ 9 runn+ ! eng9e is no long] heat1 b "w4 ,s ,may] said ! heat is n de/roy$1 b only *ang$ into "w4 ,he said1 fur!r1 t ! "w ( runn+ ! eng9e may be *ang$ aga9 into heat4 ,may]'s !ory 0 oppos$ by _m sci5tific m5 ( ,europe4 ,"o great sci5ti/ said to him t if 8 !ory 7 correct wat] c\ld be w>m$ by %ak+4 ,he rememb]$ :at ! helmsman _h rem>k$ to him on ! voyage to ,java1 t wat] beat5 ab\t by a /orm is w>m] ?an quiet sea-wat]2 b he said no?+4 ,he w5t to 8 laboratory1 tri$ ! exp]im5t1 & "s weeks lat] return$1 exclaim+3 ,x is s6 ,x is s6 ,he _h w>m$ wat] simply by %ak+ x4 ,^! results mean t "w or en]gy _c be de/roy$4 ,?\gh x *anges =m 9 _m ways1 x is nev] de/roy$4 ,nei!r c man create en]gy2 he c only direct its *anges z ! eng9e]1 by ! motion ( 8 f+] 9 op5+ a valve1 sets ! locomotive 9 motion4 ,he does n move ! locomotive4 ,he directs ! en]gy already 9 ! /eam4 ,s9ce ! "t ( ,galileo1 m5 _h caught n[ & !n a glimpse ( ?is great law4 ,galileo _h /at$ 8 law ( ma*9es2 t1 :5 a ma*9e does "w1 a man or a horse or "s o!r p[] does an equal am\nt ( "w ^u ! ma*9e4 ,c\nt ,rum=d _h p]=m$ 8 exp]im5t ) ! cannon1 %[+ t heat is produc$ by ! "w ( a horse4 ,davy _h prov$ t1 9 ! voltaic batt]y1 some?+ mu/ be us$ up to produce ! curr5t--! m]e contact ( ! metals is n suffici5t4 ,f>aday _h said t 9 no case is !re a production ( electrical p[] )\t some?+ be+ us$ up to supply x4 ,may] /at$ cle>ly ?is law ( en]gy :5 he said t en]gy _c be creat$ or de/roy$1 b only *ang$ f "o =m to ano!r4 ,& yet inv5tors h n le>n$ ! mean+ ( ?is law4 ,!y cont9ue try+ to inv5t p]petual-motion ma*9es--ma*9es t w produce "w f no?+4 ,?is is :at a p]petual-motion ma*9e w\ld be if su* a ma*9e 7 possible4 ,= a ma*9e )\t friction is impossible1 & friction means wa/$ "w--"w *ang$ into heat4 ,a ma*9e to keep itself runn+ & supply ! "w wa/$ 9 friction mu/ produce "w f no?+4 ,! great law ( nature is t y _c get some?+ = no?+4 ,:e!r y get "w1 heat1 electricity1 or light1 some?+ mu/ be us$ up to produce x4 ,= :atev] y get out ( a ma*9e y mu/ give an equival5t4 ,?is law _c be evad$1 & f x !re is no appeal4 ,*apt] ,v ,,great ,,inv5tions ,,( ,,! ,,n9ete5? ,,c5tury ,! discov]ies ( ,f>aday prep>$ ! way = ! great inv5tions ( ! n9ete5? c5tury4 ,by ! middle ( ! c5tury m5 knew h[ to control ! wond]ful p[] ( electricity4 ,!y did n "k :at electricity is1 nor d we "k to-day1 ?\gh we h made "s progress 9 t direction2 b to control x & make x furni% light1 heat1 & p[] 0 m important4 ,be=e ! inv5tions ( ,james ,watt made x possible to use /eam-p[]1 factories 7 built ne> fall+ wat]1 s t wat]-p[] c\ld be us$4 ,b ! /eam-eng9e made x possible to build great factories :]ev] a supply ( wat] = ! boil]s c\ld be obta9$4 ,cities 7 built ar\nd ! factories4 ,cities already great became great]4 ,) ! gr[? ( cities ! ne$ ( a new means ( produc+ light & p[] made itself felt4 ,electricity promis$ to become ! ,h]cules t %\ld p]=m ! tasks ( ! mod]n _w4 ,discov]y gave way to inv5tion4 ,dur+ ! second half ( ! n9ete5? c5tury _m great inv5tions 7 made & indu/ries 7 develop$1 :ile discov]ies 7 few until ne> ! close ( ! c5tury4 ,)9 ?is p]iod ! great indu/ries :i* *>act]ize our mod]n civilization1 & :i* arose out ( ! discov]ies t sci5ce _h made 9 ! c5turies prec$+1 atta9$ a high degree ( developm5t4 ,9 ?is *apt] we %all trace ! applications ( "s ( ! discov]ies ) :i* we h n[ become famili>4 ,?is w lead u into ! field ( electrical inv5tion1 = we are deal+ n[ ) ! beg9n+ ( ! _w's electrical age4 ,electric ,batt]ies ,f ! "t ( ,volta to ! "t ( ,f>aday ! only means ( produc+ an electric curr5t 0 ! voltaic batt]y1 s call$ 9 honor ( ,volta4 ,! voltaic cell is ! simple/ =m ( electric batt]y4 ,9 ?is cell ! z9c & copp] plates are plac$ 9 sulphuric acid dilut$ ) wat]4 ,z ! acid eats ! z9c1 hydrog5 gas is =m$4 ,?is gas collects 9 bubbles on ! copp] plate & weak5s ! curr5t4 ,! aim ( inv5tors 0 to produce a /eady curr5t1 to devise a batt]y 9 :i* no gas w\ld collect on ! copp] plate4 ,!y saw ! ne$ ( a batt]y t w\ld give out a curr5t ( un*ang+ /r5g? until ! z9c or ! acid 0 us$ up4 ,! fir/ real improvem5t 9 ! batt]y 0 made by ,pr(essor ,daniell1 ( ,k+'s ,college1 ,london4 ,9 ! ,daniell cell ! z9c plate is 9 dilute sulphuric acid1 & ! copp] plate is 9 a solution ( blue vitriol or copp] sulphate4 ,pr(essor ,daniell sep>at$ ! two liquids by plac+ "o ( !m 9 a tube =m$ ( ! gullet ( an ox4 ,?is tube dipp$ into ! o!r liquid4 ,! hydrog5 gas1 z x 0 =m$ by ! acid act+ on ! z9c1 c\ld g ?r\gh ! walls ( ! tube1 b 0 /opp$ by ! copp] sulphate1 & copp] 0 deposit$ on ! copp] plate4 ,?is copp] deposit 9 no way int]f]$ ) ! curr5t1 s t ! curr5t 0 n weak5$ until ! z9c plate or "o ( ! solutions 0 ne>ly consum$4 ,a cup ( por\s e>!nw>e is n[ us$ 9 ,daniell cells to sep>ate ! liquids 7,fig4 #cg74 ,by plac+ cry/als ( blue vitriol 9 ! batt]y j>1 ! solution ( blue vitriol c be kept up to its full /r5g? = a v long "t4 ,! z9c 9 "t is consum$1 & mu/ be replac$4 ,illu/ration3 ,,fig4 #cg--;,a ,,daniell ,,cell ,9 ! gravity cell 7,fig4 #ch7 ! same mat]ials are us$ z 9 ! ,daniell cell--copp] 9 copp] sulphate1 & z9c 9 sulphuric acid2 b !re is no por\s cup4 ,! solutions are kept sep>ate by gravity1 ! heavy copp] sulphate be+ at ! bottom4 ,! gravity cell has until rec5tly be5 ext5sively us$ 9 telegraphy1 & cont9ues 9 use 9 %ort-di/ance telegraphy & 9 automatic block signals4 ,! gravity & ,daniell cells are us$ = clos$-circuit "w--t is1 = "w 9 :i* ! curr5t is fl[+ almo/ con/antly4 ,illu/ration3 ,,fig4 #ch--;,a ,,gravity ,,cell ,! ,dry ,batt]y ,ano!r important improvem5t 0 ! inv5tion ( ! dry batt]y4 ,y w rememb] t ! fir/ batt]y1 ! "o inv5t$ by ,volta1 0 a =m ( dry batt]y2 b x 0 a v feeble batt]y comp>$ ) ! dry batt]ies n[ 9 use1 s t we may call ! dry batt]y a new inv5tion4 ,! dry batt]y is falsely nam$4 ,!re c be no batt]y )\t a liquid4 ,9 ! dry batt]y ! z9c cup =m+ ! outside ( ! cell is "o ( ! plates ( ! cell 7,fig4 #ci74 ,! batt]y appe>s to be dry because ! solution ( sal ammoniac is absorb$ by blott+-pap] or o!r por\s sub/ance 9 contact ) ! z9c4 ,! inn] plate is c>bon1 & ?is is surr\nd$ by p[d]$ c>bon & manganese dioxide--! latt] to remove ! hydrog5 gas :i* collects on ! c>bon plate4 ,?is gas weak5s ! curr5t :5 ! circuit has be5 clos$ = a %ort "t1 b is sl[ly remov$ :5 ! circuit is brok54 ,?us ! batt]y is said to recov]4 ,illu/ration3 ,,fig4 #ci--,,%[+ ,,:at ,,is ,,9 ,a ,,dry ,,batt]y ,! dry cell w give a /rong curr5t1 b = a %ort "t only4 ,x recov]s1 h[ev]1 if all[$ to re/4 ,x c be us$1 !re=e1 only 9 op5-circuit "w--su* z door-bell circuits1 & "s =ms ( fire & burgl> al>m4 ,a door-bell circuit is op5 ne>ly all ! "t1 ! curr5t fl[+ only :ile ! button is be+ press$4 ,"s =ms ( wet batt]y "w 9 ! same way z ! dry batt]y1 & are us$ l-wise = op5-circuit "w4 ,9 ^! batt]ies c>bon & z9c plates 9 a solution ( sal ammoniac are us$1 ! same mat]ials z 9 ! dry batt]y4 ,! only diff]5ce is t 9 ! dry batt]y ! solution is absorb$ by "s por\s sub/ance & ! batt]y seal$ s t x appe>s to be dry4 ,! ,/orage ,batt]y ,"o ( ! greate/ improvem5ts 9 electric batt]ies is ! /orage batt]y4 ,a simple /orage batt]y may be made by plac+ two /rips ( lead 9 sulphuric acid dilut$ ) wat] & connect+ ! lead /rips to a batt]y ( ,daniell cells or dry cells4 ,9 a %ort "t "o ( ! lead /rips w be f\nd cov]$ ) a r$ coat+4 ,! surface ( ?is lead /rip is no long] lead b an oxide ( lead1 some:at l ! ru/ t =ms on iron4 ,if ! lead /rips are n[ disconnect$ f ! o!r batt]y & connect$ to an electric bell1 ! bell w r+4 ,we h "h two plates1 "o ( lead & "o ( oxide ( lead1 9 dilute sulphuric acid4 ,?is =ms a /orage batt]y4 ,! fir/ /orage batt]y 0 made ( two %eets ( lead roll$ toge!r & kept ap>t by a /rip ( flannel4 ,! lead /rips ?us sep>at$ 7 imm]s$ 9 dilute sulphuric acid4 ,a curr5t f ano!r batt]y 0 pass$ ?r\gh ?is cell = a long "t--fir/ 9 "o direction1 !n 9 ! o!r4 ,?is r\gh5$ ! surface ( ! lead plates1 s t ! batt]y w\ld hold a great] *>ge4 ,! batt]y 0 !n *>g$ by pass+ a curr5t ?r\gh x 9 "o direction only = a consid]able l5g? ( "t4 ,feeble cells 7 us$ = *>g+4 ,x took days1 & sometimes weeks1 to *>ge ! fir/ /orage batt]ies4 ,!n ! /orage batt]y w\ld give out a /rong curr5t la/+ = a few h\rs4 ,x sl[ly accumulat$ en]gy :ile be+ *>g$1 & !n gave out ?is en]gy rapidly 9 ! =m ( a /rong electric curr5t4 ,= ?is reason ! /orage batt]y 0 call$ an accumulator4 ,:ile *>g+ ! /orage cell !re 0 =m$ on ! negative plate a coat+ ( s(t lead1 & on ! positive plate a coat+ ( d>k-br[n oxide ( lead4 ,x 0 f\nd bett] to apply ^! coat+s to ! lead plates be=e mak+ up ! batt]y4 ,lat] x 0 f\nd t ! batt]y w\ld hold a /ill great] *>ge if ! plates 7 made 9 ! =m ( grids 7,fig4 #dj71 & ! cavities fill$ ) ! active mat]ial--! negative ) spongy lead1 & ! positive ) d>k-br[n lead oxide4 ,"s excell5t comm]cial /orage batt]ies are made f lead plates by ! action ( an electric curr5t1 v mu* z ,plant made 8 batt]ies4 ,fig4 #da %[s "o ( ^! plates4 ,illu/ration3 ,,fig4 #dj--;,a ,,/orage ,,batt]y1 ,,%[+ ,,! ,,grids ,illu/ration3 ,,fig4 #da--;,a ,,/orage-,,batt]y ,,plate ,,made ,,f ,a ,,%eet ,,( ,,lead ,! /orage batt]y does n /ore up electricity4 ,x produces a curr5t 9 exactly ! same way z any o!r batt]y--by ! action ( ! acid on ! plates4 ,:5 ?is action ceases x is no long] a batt]y1 ?\gh x may be made "o aga9 by pass+ a curr5t ?r\gh x 9 ! opposite direction f t :i* x gives out4 ,9 ?is x diff]s f ! voltaic batt]y1 = :5 su* a batt]y is run d[n x c be re/or$ only by add+ new solution or new plates4 ,! /orage batt]y is especially useful = sp>k+ 9 gas or gasol5e motors4 ,edison has inv5t$ a /orage batt]y t w d z mu* "w z a lead batt]y ( twice its weight4 ,edison's batt]y is int5d$ especially = use 9 electric automobiles4 ,by r$uc+ ! weight ( ! batt]y :i* ! ma*9e mu/ c>ry ! weight ( ! truck may also be r$uc$4 ,9 ! ,edison batt]y ! positive plates are made ( a grid ( nickel-plat$ /eel conta9+ tubes fill$ ) pure nickel4 ,! negative plate consi/s ( a nickel-plat$ /eel grid conta9+ an oxide ( iron simil> to common iron-ru/4 ,aft] work+ a numb] ( ye>s on ?is batt]y & mak+ n9e ?\s& exp]im5ts1 ,edison ?\ght he _h x p]fect$1 & inde$ x 0 a great improvem5t ov] ! /orage batt]ies t _h be5 us$--mu* light] & *eap]1 & m successful 9 op]ation4 ,two hundr$ & fifty automobiles 7 equipp$ ) x1 & x prov$ sup]ior to lead batt]ies = ?is purpose4 ,b x 0 n to ,edison's lik+4 ,he ?rew ! ma*9]y1 wor? ?\s&s ( doll>s1 on ! scrap-heap1 & work$ on = six ye>s4 ,he _h !n produc$ a batt]y z mu* bett] ?an ! fir/ z ! fir/ 0 bett] ?an ! lead batt]y1 & he 0 cont5t to h ! new batt]y plac$ on ! m>ket4 ,! ,dynamo ,= ! purpose ( light+ & p[] ! electric batt]y prov$ too co/ly4 ,davy produc$ an arc light ) a batt]y ( f\r ?\s& cells4 ,! arc 0 ab\t f\r in*es 9 l5g? & yield$ a brilliant light1 b z ! co/ 0 six doll>s a m9ute x 0 n ?\ght practical4 ,attempts 7 made e>ly 9 ! c5tury to use a batt]y curr5t = p[]1 b !y fail$ because ( ! co/ & ! fact t no good work+ motor _h be5 inv5t$4 ,light & p[] 7 ne$$4 ,electricity c\ld supply bo?4 ,b h[ ov]come ! difficulty ( co/1 & produce an electric curr5t f burn+ coal or fall+ wat]8 ,= answ] man look$ to ! great discov]y ( ,f>aday & 8 new electrical ma*9e4 ,inv5tors 9 ,g]many1 ,france1 ,engl&1 ,italy1 & ,am]ica made improvem5ts until f ! disk dynamo ( ,f>aday !re _h evolv$ ! mod]n dynamo4 ,electroplat+ & ! telegraph are ! only applications ( ! electric curr5t t became factors 9 ! _w's indu/ry be=e ! dynamo1 yet 9 long-di/ance telegraphy & 9 electroplat+ to-day ! dynamo is us$4 ,)\t ! dynamo1 electric light+1 electric p[]1 & electric traction z develop$ 9 ! n9ete5? c5tury w\ld h be5 impossible2 9 fact1 ! dynamo ) ! electric motor 7:i*1 z we %all see1 is only a dynamo rev]s$7 is ma/] ( ! field4 ,! way _h be5 prep>$ = ! application ( ,f>aday's discov]y by ,william ,/urgeon1 an ,engli%man1 & ,joseph ,h5ry1 an ,am]ican4 ,/urgeon discov]$ t s(t iron is m quickly magnetiz$ ?an /eel1 & f\nd t ! /r5g? ( an electromagnet c be greatly increas$ by mak+ ! core ( a s(t-iron rod & b5d+ ! rod into ! =m ( a horse%oe 7,fig4 #db74 ,! iron rod 0 coat$ ) seal+-wax & w\nd ) a s+le lay] ( copp] wire1 ! turns ( wire n t\*+4 ,?is 0 9 #ahbe1 be=e ,f>aday discov]$ ! pr9ciple ( ! dynamo4 ,illu/ration3 ,,fig4 #db--,,/urgeon',s ,,electromagnet ,pr(essor ,h5ry /ill fur!r increas$ ! /r5g? ( ! electromagnet by cov]+ ! wire ) silk1 :i* made x possible to w9d sev]al lay]s ( wire on ! iron core1 & _m times ! l5g? ( wire t _h be5 us$ by ,/urgeon4 ,fig4 #dc %[s su* a magnet4 ,"o ( ,h5ry's magnets weigh$ fifty-n9e & a half p\nds1 & w\ld hold up a ton ( iron4 ,/urgeon said3 ,pr(essor ,h5ry has produc$ a magnetic =ce :i* completely eclipses e o!r 9 ! :ole annals ( magnetism4 ,) ,pr(essor ,h5ry's inv5tion ! electromagnet 0 ready = use 9 ! dynamo4 ,fig4 #dd %[s a /rong electromagnet4 ,illu/ration3 ,,fig4 #dc--;,,an ,,electromagnet ,,) ,,_m ,,turns ,,( ,,insulat$ ,,wire ,illu/ration3 ,,fig4 #dd--;,,an ,,electromagnet ,,lift+ ,,twelve ,,tons ,,( ,,iron ,a mov+ magnet causes a curr5t to fl[ 9 a coil1 b a magnet at re/ has no effect4 ,a mov+ magnet is equal to a batt]y4 ,9 ,f>aday's exp]im5ts a curr5t 0 induc$ 9 a coil ( wire by mov+ a magnet 9 ! coil or by mak+ & break+ ! circuit 9 ano!r coil w\nd on ! same iron core4 ,a curr5t 0 induc$ 9 a metal disk by revolv+ x betwe5 ! poles ( a magnet4 ,9 e case !re 0 motion 9 a magnetic field1 or ! field itself 0 *ang$4 ,a *ang+ magnetic field is equal to a mov+ magnet4 ,:at is ne$$ to induce a curr5t 9 a coil1 :e!r x be 9 a dynamo1 an induction-coil1 or a trans=m]1 is a *ang+ magnetic field ab\t ! coil or motion ( ! coil 9 ! magnetic field4 ,if f9e iron fil+s are spr9kl$ ov] ! poles ( a magnet ! fil+s arrange !mselves 9 def9ite l9es4 ,?is is a simple exp]im5t :i* any boy c try = himself4 ,f>aday call$ ! l9es m>k$ out by ! iron fil+s l9es ( =ce 7! l9es ( =ce ( a horse%oe magnet are %[n 9 ,fig4 #cf71 because !y indicate ! direction 9 :i* ! magnet pulls a piece ( iron--t is1 ! direction ( ! magnetic =ce4 ,n[1 if a curr5t is to be induc$ 9 a wire1 ! wire mu/ move across ! l9es ( =ce4 ,if ! wire moves along ! l9es m>k$ out by ! iron fil+s1 !re w be no curr5t4 ,:5 a coil rotates betwe5 ! poles ( a magnet1 ! wire moves across ! l9es ( =ce & a curr5t is induc$ 9 ! coil if ! circuit is clos$4 ,?is is ! way a curr5t is produc$ 9 a dynamo4 ,f>aday produc$ a curr5t by rotat+ a coil betwe5 ! poles ( a /eel magnet4 ,he made a numb] ( su* ma*9es1 & us$ !m ) "s success 9 produc+ lights = ligh?\ses1 b ! defects ( ^! ma*9es 7 s great t ! light+ ( a city or ! developm5t ( p[] on a l>ge scale 0 impractical4 ,! electromagnet 0 ne$$ to solve ! problem4 ,siem5s' ,dynamo ,! w> ( #ahff betwe5 ,au/ria & ,prussia & ! c]ta9ty ( a com+ /ruggle ) ,france turn$ ! att5tion ( ,g]man inv5tors to ! use ( electricity 9 w>f>e4 ,w]n] von ,siem5s1 an artill]y (fic]1 0 improv+ an explod+ device = m9es4 ,an electric curr5t 0 ne$$ to produce a sp>k or heat a wire to r$ness 9 ! p[d]4 ,f>aday _h us$ a coil ( wire turn+ betwe5 ! poles ( a /eel magnet to produce a curr5t4 ,9 ,engl& a coil turn+ betwe5 ! poles ( an electromagnet _h be5 us$1 b ! electromagnet receiv$ its curr5t f ano!r ma*9e 9 :i* a /eel magnet 0 us$4 ,siem5s f\nd t ! /eel magnet c\ld be disp5s$ )1 & t a coil turn+ betwe5 ! poles ( an electromagnet c\ld furni% ! curr5t = ! electromagnet4 ,two ?+s are ne$$1 !n1 to make a dynamo3 an electromagnet & a coil to turn betwe5 ! poles ( t magnet4 ,! rotat+ coil1 :i* usually conta9s a s(t-iron core1 is call$ ! armature4 ,! coil w furni% curr5t = ! magnet & "s to sp>e2 9 fact1 only a small "p ( ! curr5t induc$ 9 ! coil is ne$$ to keep ! magnet up to its full /r5g?1 & ! great] "p ( ! curr5t may be us$ = light+ or p[]4 ,! new ma*9e 0 nam$ by its inv5tor ! dynamo-electric ma*9e4 ,! "n has s9ce be5 %ort5$ to dynamo4 ,! fir/ practical problem :i* ! dynamo solv$ 0 ! con/ruction ( an electric explod+ app>atus )\t ! use ( /eel magnets or batt]ies4 ,a dynamo ) ,siem5s' armature is %[n 9 ,fig4 #de4 ,illu/ration3 ,,fig4 #de--;,a ,,dynamo ,,) ,,siem5s' ,,armature ,9 8 fir/ en?usiasm ! inv5tor dream$ ( great ?+s = ! new ma*9e1 among o!rs an electric /reet railway 9 ,b]l94 ,b ! dynamo 0 n yet ready4 ,! difficulty 0 ! heat+ ( ! iron core ( ! armature1 caus$ by ! action ( induc$ curr5ts4 ,!re are induc$ curr5ts 9 ! iron core z well z 9 ! coil1 &1 = ! same reason1 ! coil & ! iron core )9 x are bo? mov+ 9 a magnetic field4 ,^! little curr5ts circl+ r\nd & r\nd 9 ! iron core produce heat4 ,! rapid *ang+ ( ! magnetism ( ! iron also heats ! iron4 ,x rema9$ = ,gramme1 9 ,france1 to apply ! prop] rem$y4 ,?is rem$y 0 an armature 9 :i* ! coil 0 w\nd on an iron r+1 inv5t$ by an ,italian1 ,pac9otti4 ,gramme appli$ ! pr9ciple discov]$ by ,siem5s to ,pac9otti's r+1 & produc$ ! fir/ practical dynamo = /rong curr5ts4 ,?is 0 9 #ahfh4 ,a r+ armature is %[n 9 ,fig4 #df4 ,! fir/ dynamo pat5t$ 9 ! ,unit$ ,/ates is %[n 9 ,fig4 #dg4 ,?is dynamo is only a curiosity4 ,illu/ration3 ,,fig4 #df--,,r+ ,,armature ,illu/ration3 ,,fig4 #dg--;,,fir/ ,,dynamo ,,pat5t$ ,,9 ,,! ,,unit$ ,,/ates ,int5d$ to be us$ = kill+ :ales4 ,photo by ,claudy4 ,! ,drum ,armature ,an improvem5t 9 ! ,siem5s armature 0 made f\r ye>s lat] by ,von ,hefn]-,alt5eck1 an eng9e] 9 ! employ ( ,siem5s4 ,?is improvem5t consi/$ 9 w9d+ on ! iron core a numb] ( coils simil> to ! "o coil ( ! ,siem5s armature1 b w\nd 9 diff]5t directions4 ,?is is call$ ! drum armature 7,fig4 #dh74 ,! heat+ ( ! core is prev5t$ by build+ x up ( a numb] ( ?9 iron plates insulat$ f "o ano!r & by air-spaces )9 ! core4 ,! insulation prev5ts ! small curr5ts f fl[+ ar\nd 9 ! core4 ,! air-spaces s]ve = cool+4 ,! drum armature 0 a great improvem5t ov] bo? ! ,siem5s & ! ,gramme armatures4 ,) ! ,siem5s "o-coil armature !re is a po9t 9 ea* revolution at :i* !re is no curr5t4 ,! curr5t1 !re=e1 v>ies dur+ ea* revolution ( ! armature f z]o to full /r5g?4 ,9 ! ,gramme armature only half ! wire1 ! "p on ! outside ( ! r+1 receives ! full effect ( ! magnetic field4 ,! inn] half is practically useless1 except to c>ry ! curr5t :i* is g5]at$ 9 ! out] half4 ,bo? ^! difficulties are avoid$ 9 ! drum armature4 ,! dynamos ( to-day are modifications ( ! two k9ds inv5t$ by ,siem5s & ,gramme4 ,_m special =ms h be5 design$ = special k9ds ( "w4 ,illu/ration3 ,,fig4 #dh--;,a ,,drum ,,armature1 ,,%[+ ,,h[ ,,an ,,armature ,,( ,,f\r ,,coils ,,is ,,w\nd ,edison's ,comp\nd-,w\nd ,dynamo ,edison1 9 8 "w on ! electric light & ! electric railway1 made "s important improvem5ts 9 ! dynamo4 ,! armature ( a dynamo is usually turn$ by a /eam-eng9e4 ,edison f\nd t mu* p[] 0 wa/$ 9 ! use ( belts to connect ! eng9e & ! dynamo4 ,he !re=e connect$ ! eng9e direct to ! dynamo1 plac+ ! armature ( ! dynamo on ! %aft ( ! eng9e4 ,he also us$ m p[]ful field-magnets ?an _h be5 us$ be=e4 ,8 greate/ improvem5t1 h[ev]1 0 9 mak+ ! dynamo self-regulat+1 s t ! dynamo w s5d out ! /r5g? ( curr5t t is ne$$4 ,su* a dynamo w s5d out m curr5t :5 m lights are turn$ on4 ,:e!r x supplies curr5t = "o light or a ?\s&1 x s5ds out j ! curr5t t is ne$$--no m1 no less4 ,x w d ?is if no human be+ is ne>4 ,an att5dant is ne$$ only to keep ! ma*9]y well oil$ & see t ea* "p is 9 work+ ord]4 ,edison br\ght ab\t ?is improvem5t by 8 improv$ me?od ( w9d+4 ,?is me?od is kn[n z comp\nd w9d+4 ,to und]/& comp\nd w9d+ we mu/ fir/ und]/& two o!r me?ods ( w9d+4 ,9 ! s]ies w9d+ 7,fig4 #di71 all ! curr5t g5]at$ 9 ! armature fl[s ?r\gh ! coils ( ! field-magnet4 ,!re is only "o circuit4 ,! same curr5t fl[s ?r\gh ! coils ( ! magnet & ?r\gh ! out] circuit1 :i* may conta9 lights or motors4 ,su* a dynamo is commonly us$ = arc lights4 ,x w n regulate itself4 ,if left to itself x w give less electrical pressure :5 m pressure is ne$$4 ,x requires a special regulator4 ,illu/ration3 ,,fig4 #di--;,a ,,s]ies-,,w\nd ,,dynamo ,9 ! second =m ( w9d+ ! curr5t is divid$ into two bran*es4 ,"o bran* goes ?r\gh ! coils ( ! field-magnet4 ,! o!r bran* goes ?r\gh ! l9e wire = use 9 lights or motors4 ,?is is call$ ! %unt w9d+ 7,fig4 #ej74 ,! %unt-w\nd dynamo is us$ = inc&esc5t lights4 ,x also requires a special regulator1 = if left to itself x gives less electrical pressure :5 ! pressure %\ld be kept ! same4 ,illu/ration3 ,,fig4 #ej--;,a ,,%unt-,,w\nd ,,dynamo ,! comp\nd w9d+ 7,fig4 #ea71 :i* 0 fir/ us$ by ,edison1 is a comb9ation ( ! s]ies & %unt w9d+s4 ,illu/ration3 ,,fig4 #ea--;,a ,,comp\nd-,,w\nd ,,dynamo ,! curr5t is divid$ into two bran*es4 ,"o bran* goes only ?r\gh ! field-coils4 ,! o!r bran* goes ?r\gh additional coils :i* are w\nd on ! field-magnet1 & also ?r\gh ! ext]nal circuit4 ,su* a dynamo c be made self-regulat+1 s t x w give always ! same electrical pressure :atev] ! numb] ( lamps or motors ?r[n into ! circuit4 ,9 ma9ta9+ always ! same pressure x ( c\rse supplies m or less curr5t1 accord+ to ! am\nt ( curr5t t is ne$$4 ,?is is cle> if we comp>e ! fl[ ( electric curr5t ) ! fl[ ( wat]4 ,op5 a wat]-faucet & notice h[ fa/ ! wat] fl[s4 ,!n op5 sev]al o!r faucets connect$ ) ! same wat]-pipe4 ,probably ! wat] w n fl[ s fa/ f ! fir/ faucet4 ,t is because ! pressure has be5 l[]$ by ! fl[ ( wat] f ! o!r faucets4 ,if we c\ld make ! wat] adju/ its own pressure & keep ! pressure always ! same1 !n ! wat] w\ld always fl[ at ! same rate ?r\gh a faucet1 no matt] h[ _m o!r faucets 7 op5$4 ,?is is :at happ5s 9 ! ,edison comp\nd-w\nd dynamo4 ,turn on "o #af-;c&le-p[] c>bon lamp4 ,x takes ab\t half an amp]e ( curr5t4 ,turn on a hundr$ lamps connect$ to ! same wires1 & ! dynamo ( its own accord keeps ! pressure ! same1 & supplies fifty amp]es1 or half an amp]e = ea* lamp4 ,) ?is inv5tion ( ,edison ! dynamo 0 practically complete1 & ready to furni% curr5t = any purpose = :i* curr5t might be ne$$4 ,fig4 #eb %[s "o ( ,edison's fir/ dynamos4 ,fig4 #ec %[s a dynamo us$ = light+ a railway coa*4 ,illu/ration3 ,,fig4 #eb--,,"o ,,( ,,edison',s ,,fir/ ,,dynamos ,p]mission ( ,association ( ,edison ,illum9at+ ,companies4 ,illu/ration3 ,,fig4 #ec--;,a ,,dynamo ,,m\nt$ ,,on ,,! ,,truck ,,( ,a ,,railway ,,c> ,! dynamo furni%es curr5t = ! electric lights 9 ! c>4 ,:5 ! tra9 is n runn+ ! curr5t is furni%$ by a /orage batt]y4 ,electric ,p[] ,x has be5 said t ! n9ete5? c5tury 0 ! age ( /eam1 b ! tw5tie? w be ! age ( electricity4 ,be=e ! end ( ! n9ete5? c5tury1 h[ev]1 electric p[] _h become a reality1 & !re rema9$ only developm5t along practical l9es4 ,we mu/ turn to ,o]/$1 ,ampre1 & ,f>aday to f9d ! beg9n+ ( electric p[]4 ,9 ,o]/$'s exp]im5t1 motion ( a magnet 0 produc$ by an electric curr5t4 ,ampre f\nd t electric curr5ts attract or repel ea* o!r1 & ?is because ( _! magnetic action4 ,f>aday f\nd t "o pole ( a magnet w sp9 r\nd a wire ?r\gh :i* a curr5t is fl[+4 ,"h 0 motion produc$ by an electric curr5t4 ,^! great sci5ti/s discov]$ ! pr9ciples t 7 appli$ lat] by inv5tors 9 ! electric motor4 ,a numb] ( motors 7 inv5t$ 9 ! e>ly ye>s ( ! c5tury1 b !y 7 ( no practical use4 ,x 0 n until aft] ! inv5tion ( ! ,gramme & ,siem5s dynamos t a practical motor 0 possible4 ,x 0 f\nd t "o ( ^! dynamos w\ld run z a motor if a curr5t 7 s5t ?r\gh ! coils ( ! armature & ! field-magnet2 9 fact1 ! curr5t f "o dynamo may be made to run ano!r simil> ma*9e z a motor4 ,?us ! dynamo is said to be rev]sible4 ,if ! armature is turn$ by a /eam-eng9e or "s o!r p[]1 a curr5t is produc$4 ,if a curr5t is s5t ?r\gh ! coils1 ! armature turns & does "w4 ,if ! ma*9e is us$ to supply an electric curr5t1 x is a dynamo4 ,if us$ to d "w--z1 = example1 to propel a /reet-c> & = t purpose receives a curr5t--x is a motor4 ,! same ma*9e may be us$ = ei!r purpose4 ,9 practice !re are "s diff]5ces 9 ! w9d+ ( ! coils ( dynamos & motors1 yet any dynamo c be us$ z a motor & any motor c be us$ z a dynamo4 ,?is discov]y made x possible to transmit p[] to a di/ance ) little wa/e z well z to divide ! p[] easily4 ,! curr5t f "o l>ge dynamo may light /reets & h\ses1 & at ! same "t run a numb] ( motors 9 factories or /reet-c>s at great di/ances ap>t4 ,a c5tral-/ation dynamo may run ! motors t propel hundr$s ( /reet-c>s4 ,dynamos at ,niag>a furni% curr5t = motors 9 ,buffalo & o!r cities4 ,"o great sci5ti/1 :o no d\bt =e-saw ! wond]s ( electricity :i* we "k s well to-day1 said t ! greate/ discov]y ( ! n9ete5? c5tury 0 t ! ,gramme ma*9e is rev]sible4 ,! ,fir/ ,electric ,railway ,! electric railway 0 made possible by ! inv5tion ( ! dynamo & ! discov]y t ! dynamo is rev]sible4 ,at ! ,indu/rial ,exposition 9 ,b]l9 9 #ahgi !re 0 exhibit$ ! fir/ practical electric locomotive1 ! inv5tion ( ,doctor ,siem5s4 ,! locomotive & its pass5g]-coa* 7 absurdly small4 ,! track 0 circul>1 & ab\t "o ?\s& feet 9 l5g?4 ,?is dim9utive railway 0 ref]r$ to by an ,am]ican magaz9e z ,siem5s' electrical m]ry-g-r\nd4 ,b ! electrical m]ry-g-r\nd ar\s$ great int]e/ because ( ! possibilities x repres5t$ 7,fig4 #ed74 ,illu/ration3 ,,fig4 #ed--;,,fir/ ,,electric ,,locomotive ,! curr5t 0 g5]at$ by a dynamo 9 ,ma*9]y ,hall1 ?is dynamo be+ run by a /eam-eng9e4 ,an exactly simil> dynamo m\nt$ on :eels =m$ ! locomotive4 ,! curr5t f ! dynamo 9 ,ma*9]y ,hall 0 us$ to run ! o!r z a motor & s propel ! c>4 ,! rails s]v$ to conduct ! curr5t4 ,a ?ird rail 9 ! middle ( ! track 0 connect$ to "o pole ( ! dynamo & ! two out] rails to ! o!r pole4 ,a small trolley :eel made contact ) ! ?ird rail4 ,! rails 7 n insulat$1 b x 0 f\nd t ! leakage curr5t 0 v small1 ev5 :5 ! gr\nd 0 wet4 ,! success ( ?is exp]im5t ar\s$ great int]e/1 n only 9 ,g]many1 b 9 ,europe & ,am]ica4 ,am]ica's greate/ inv5tor1 ,edison1 took up ! problem4 ,edison employ$ no trolley l9e or ?ird rail1 b only ! two rails ( ! track z conductors1 s5d+ ! curr5t out ?r\gh "o rail & back ?r\gh ! o!r4 ,( c\rse1 ?is meant t ! :eels mu/ be insulat$1 s t ! curr5t c\ld fl[ f "o rail to ! o!r only ?r\gh ! coils ( ! motor4 ,z 9 ,siem5s' exp]im5t1 ! motor 0 ( ! same con/ruction z ! dynamo4 ,! rails 7 n insulat$1 & x 0 f\nd t1 ev5 :5 ! track 0 wet1 ! loss ( electric curr5t 0 n m ?an #e p] c5t4 ,edison f\nd t he c\ld realize 9 8 motor #gj p] c5t4 ( ! p[] appli$ to ! dynamo1 :]eas ! ,g]man inv5tor 0 able to realize only #fj p] c5t4 ,! improvem5t 0 l>gely due to ! improv$ w9d+4 ,edison 0 ! fir/ to use 9 practical "w ! comp\nd-w\nd dynamo1 & ?is 0 done 9 connection ) 8 electric railway4 ,fig4 #ee %[s ,edison's fir/ electric locomotive4 ,illu/ration3 ,,fig4 #ee--;,,fir/ ,,edison ,,electric ,,locomotive ,! "q ( ge>+ 0 a tr\blesome "o4 ,! armature %aft ( ! motor 0 at fir/ connect$ by friction ge>+ to ! axle ( two :eels ( ! locomotive4 ,lat] a belt & pulleys 7 us$4 ,an idl] pulley 0 us$ to tight5 ! belt4 ,:5 ! motor 0 />t$ & ! belt quickly tight5$ ! armature 0 burn$ out4 ,?is happ5$ a numb] ( times4 ,!n ,mr4 ,edison br\ght out f ! laboratory a numb] ( resi/ance-boxes1 plac$ !m on ! locomotive1 & connect$ !m 9 s]ies ) ! armature4 ,^! resi/ances w\ld p]mit only a small curr5t to fl[ ?r\gh ! motor z x 0 />t+1 & s prev5t ! burn+-out ( ! armature coils4 ,! locomotive 0 />t$ ) ! resi/ance-boxes 9 circuit1 & aft] ga9+ "s spe$ ! op]ator w\ld plug ! v>i\s boxes out ( circuit1 & 9 t way increase ! spe$4 ,:5 ! motor is runn+ !re is a back-pressure1 or a pressure t w\ld cause a curr5t to fl[ 9 ! opposite direction f t :i* is runn+ ! motor4 ,because ( ?is back-pressure ! curr5t :i* actually fl[s ?r\gh ! motor is small1 & ! resi/ance-boxes may be safely tak5 out ( ! circuit4 ,f9d+ ! resi/ance-boxes scatt]$ ab\t "u ! seats & on ! plat=m z !y 7 a nuisance1 ,mr4 ,edison ?rew !m aside1 & us$ "s coils ( wire w\nd on ! motor field-magnet :i* c\ld be plugg$ out ( ! circuit 9 ! same way z ! resi/ance-boxes4 ,?is device ( ,edison's 0 ! orig9 ( ! controll]1 ?\gh 9 ! controll] n[ us$ on /reet-c>s n only is ! resi/ance cut out z ! spe$ ( ! c> increases1 b ! electrical connections ( ! motor are *ang$ 9 su* a way z to increase its spe$ gradually4 ,fig4 #ef %[s ,edison's fir/ pass5g] locomotive4 ,illu/ration3 ,,fig4 #ef--;,,edison',s ,,fir/ ,,pass5g] ,,locomotive ,! news ( ! little electric railway at ! ,indu/rial ,exposition 9 ,b]l9 0 soon nois$ abroad1 & ! ,g]man inv5tor receiv$ inquiries f all p>ts ( ! _w1 indicat+ t ef=ts w\ld be made 9 o!r c\ntries to develop practical electrical railways4 ,! firm ( ,siem5s ,halske !re=e det]m9$ to build a l9e = actual traffic1 n = pr(it1 b t ,g]many might h ! honor ( build+ ! fir/ practical electric railway4 ,! l9e 0 built betwe5 ,b]l9 & ,li*t]felde1 a di/ance ( ab\t "o & a half miles4 ,a horse-c> seat+ tw5ty-six p]sons 0 press$ into s]vice4 ,a motor 0 m\nt$ betwe5 ! axles1 & a c5tral-/ation dynamo exactly l ! motor 0 in/all$4 ,z 9 ,edison's exp]im5tal railway1 ! two rails ( ! track 7 us$ to c>ry ! curr5t4 ,?is electric l9e replac$ an omnibus l9e1 & 0 imm$iately us$ = regul> traffic1 & ?us ! electric railway 0 laun*$ ^u its rem>kable c>e]4 ,! fir/ electric c> us$ = comm]cial s]vice is %[n 9 ,fig4 #eg4 ,illu/ration3 ,,fig4 #eg--;,,fir/ ,,comm]cial ,,electric ,,railway ,an old horse-c> conv]t$ into an electric c>4 ,electric ,light+ ,f ! "t :5 ! night-wat*man c>ri$ a lant]n to ! "t ( brilliantly light$ /reets 0 less ?an a c5tury4 ,x 0 a "t :5 ! rapid gr[? ( railways & comm]ce br\ght ab\t a rapid gr[? ( cities1 & ) ! gr[? ( cities ! ne$ ( illum9ation4 ,factories mu/ run at night to meet ! _w's dem&s4 ,comm]ce _c /op :5 ! sun sets4 ,! c5tres ( comm]ce mu/ h light4 ,dur+ ?is "t sci5ti/s 7 at "w 9 _! laboratories develop+ means = produc+ a high vacuum4 ,!y 7 able to pump ! air out ( a glass bulb until less ?an a million? "p ( ! air rema9$4 ,!y little dream$ t !re 0 any connection betwe5 ! high vacuum & ! problem ( light+4 ,discov]]s 7 at "w br++ to light ! pr9ciples n[ utiliz$ 9 ! dynamo4 ,9 ! fulness ( "t ^! factors 7 br\ght toge!r to produce an effici5t sy/em ( light+4 ,= a "t gas replac$ ! lant]n ( ! night-wat*man1 only to yield ! great] portion ( ! field to its rival1 electricity4 ,! fir/ ef=ts 7 9 ! direction ( ! arc light4 ,f ! e>lie/ times ! light giv5 out by an electric sp>k _h be5 obs]v$4 ,x 0 ! aim ( inv5tors to produce a cont9u\s sp>k t %\ld give out a brilliant light4 ,x 0 ?\ght = a "t t ! electric batt]y w\ld solve ! problem1 b ! co/ ( ! batt]y curr5t 0 too great4 ,aga9 we are indebt$ to ,f>aday1 = x 0 ! dynamo t made electric light+ possible4 ,an arc light is produc$ by an electric curr5t fl[+ across a gap betwe5 two /icks ( c>bon4 ,! air (f]s v great resi/ance to ! fl[ ( electric curr5t across ?is gap4 ,n[ :5ev] an electric curr5t fl[s ?r\gh some?+ :i* resi/s its fl[1 heat is produc$4 ,! high resi/ance ( ! air-gap causes su* int5se heat t ! tips ( ! c>bons become :ite hot & give out a brilliant light4 ,if exam9$ ?r\gh a smok$ glass a beautiful blue arc ( c>bon vapor may be se5 betwe5 ! c>bon tips4 ,if ! curr5t fl[s 9 "o direction only1 "o ( ! c>bons1 ! positive1 becomes hott] & bright] ?an ! o!r4 ,9 #ahgh ! /reets ( ,p>is 7 light$ ) ! ,jablo*k(f c&le1 a =m ( arc light suppli$ ) curr5t by ! ,gramme ma*9e4 ,9 ! same ye> ! ,bru% sy/em ( arc light+ 0 giv5 to ! public4 ,?is 0 ! beg9n+ ( our pres5t sy/em ( arc light+4 ,! electric arc is suitable = light+ /reets & = l>ge build+s1 b _c be us$ = light+ h\ses4 ,! light is too int5se4 ,"o arc w\ld furni% en\gh light = a numb] ( h\ses if ! light c\ld be divid$ s t !re might be j ! "r am\nt ( light 9 ea* room4 ,b ?is is impossible ) ! electric arc4 ,! ,edison sy/em ( inc&esc5t light+ 0 requir$ to solve ! problem ( light+ h\ses by electricity4 ,9 #ahhj ! ,edison sy/em 0 br\ght out = comm]cial use4 ,edison's problem 0 to produce a light t c\ld be divid$ into a numb] ( small lights1 & "o t w\ld require less att5tion ?an ! arc light4 ,he tri$ pass+ a curr5t ?r\gh plat9um wire enclos$ 9 a vacuum4 ,?is gave a fairly good light1 b 0 n :olly satisfactory4 ,he sat "o night ?9k+ ab\t ! problem1 unconsci\sly f+]+ a bit ( lampblack mix$ ) t> :i* he _h us$ 9 8 telephone4 ,n ?9k+ :at he 0 do+1 he roll$ ?is mixture ( t> & lampblack into a ?read4 ,!n he notic$ :at he _h done1 & ! ?\ght occurr$ to him3 ,:y n pass an electric curr5t ?r\gh ?is ?read ( c>bon8 ,he tri$ x4 ,a fa9t gl[ 0 ! result4 ,he felt t he 0 on ! "r track4 ,a piece ( cotton ?read mu/ be heat$ 9 a furnace 9 an iron mold1 :i* w\ld prev5t ! ?read f burn+ by keep+ out ! air4 ,!n all ! o!r elem5ts t 7 9 ! ?read w\ld be driv5 out & only ! c>bon rema94 ,= ?ree days he work$ )\t sleep to prep>e ?is c>bon filam5t4 ,at ! end ( two days he succe$$ 9 gett+ a p]fect filam5t1 b :5 he attempt$ to seal x 9 ! glass bulb x broke4 ,he pati5tly work$ ano!r day1 & 0 rew>d$ by secur+ a good c>bon filam5t1 seal$ 9 a glass globe4 ,he pump$ ! air out ( ?is globe1 seal$ x1 & s5t a curr5t ?r\gh ! c>bon ?read4 ,he tri$ a weak curr5t at fir/4 ,!re 0 a fa9t gl[4 ,he increas$ ! curr5t4 ,! ?read gl[$ m brightly4 ,he cont9u$ to increase ! curr5t until ! sl5d] ?read ( c>bon1 :i* w\ld crumble at a t\*1 0 c>ry+ a curr5t t w\ld melt a wire ( plat9um /rong en\gh to support a weight ( sev]al p\nds4 ,! c>bon gave a bright light4 ,he _h f\nd a means ( caus+ ! electric curr5t to furni% a l>ge numb] ( small lights4 ,fig4 #eh is an excell5t photograph ( ,edison at "w 9 8 laboratory4 ,fig4 #ei %[s "s ( ,edison's fir/ inc&esc5t lamps4 ,he next set out 9 se>* ( ! be/ k9d ( c>bon = ! purpose4 ,he c>boniz$ pap] & wood ( v>i\s k9ds--9 fact1 ev]y?+ he c\ld f9d t w\ld yield a c>bon filam5t4 ,he tri$ ! fibres ( a ,japanese fan made ( bamboo1 & f\nd t ?is gave a bett] light ?an any?+ he _h tri$ be=e4 ,he !n began ! se>* = ! be/ k9d ( bamboo4 ,he le>n$ t !re are ab\t twelve hundr$ v>ieties ( bamboo4 ,he mu/ h a sample ( e v>iety4 ,he s5t m5 into e "p ( ! _w :]e bamboo gr[s4 ,"o man travell$ ?irty ?\s& miles & _h _m enc\nt]s ) wild bea/s 9 8 se>* = ! samples ( bamboo4 ,at la/ a ,japanese bamboo 0 f\nd t 0 bett] ?an any o!r4 ,! se>* = ! c>bon fibre _h co/ ab\t a hundr$ ?\s& doll>s4 ,lat] x 0 f\nd t a squirt$ filam5t c\ld be made t work$ z well z ! bamboo fibre4 ,?is 0 made by dissolv+ cotton wool 9 a c]ta9 solution1 & !n squirt+ ?is solution ?r\gh a small hole into a small tank conta9+ alcohol4 ,! alcohol causes ! sub/ance to set & h>d51 & ?us =ms a c>bon ?read ! size ( ! hole4 ,fig4 #fj %[s ! fir/ comm]cial electric-light+ plant1 :i* 0 in/all$ on ! /eam%ip ,columbia 9 #ahhj4 ,illu/ration3 ,copyright1 #aijd1 by ,byron1 ,n4 ,y4 ,,fig4 #eh--;,,edison1 ,,am]ica',s ,,greate/ ,,inv5tor1 ,,at ,,"w ,,9 ,,8 ,,laboratory ,illu/ration3 ,copyright1 #aijd1 by ,william ,j4 ,hamm] ,,fig4 #ei--;,,edison',s ,,fam\s ,,horse%oe ,,pap]-,,filam5t ,,lamp ,,( #ahgj ,illu/ration3 ,,fig4 #fj--;,,fir/ ,,comm]cial ,,edison ,,electric-,,light+ ,,plant2 ,,in/all$ ,,on ,,! ,,/eam%ip ,,columbia ,,9 ,,may1 #ahhj ,! c>bon ?read 9 ! inc&esc5t light is heat$ to a :ite heat1 & because x is s heat$ x gives out light4 ,9 air su* a t9y ?read ( :ite-hot c>bon w\ld burn 9 a fraction ( a second4 ,! c>bon mu/ be 9 a vacuum1 & s ! air is pump$ out ( ! light bulb ) a special k9d ( air-pump inv5t$ n long be=e ,edison began 8 "w on ! electric light4 ,?is pump is capable ( tak+ out practically all ! air t 0 9 ! bulb4 ,p]haps a million? "p ( ! orig9al air rema9s4 ,a great inv5tion is nev] complet$ by "o man4 ,x 0 to be expect$ t ! electric light w\ld be improv$4 ,a numb] ( k9ds ( inc&esc5t light h be5 devis$1 us+ diff]5t k9ds ( filam5ts & adapt$ to a v>iety ( uses4 ,! orig9al ,edison c>bon lamp1 h[ev]1 cont9ues 9 use1 be+ bett] adapt$ to c]ta9 purposes ?an ! new] =ms4 ,! m]cury vapor light des]ves m5tion z a special =m ( arc light4 ,9 ! ord9>y arc light ! arc is =m$ ( c>bon vapor1 & ! light is giv5 out f ! tips ( ! :ite-hot c>bons4 ,9 ! m]cury vapor light ! light is giv5 out f ! m]cury vapor :i* =ms ! arc4 ,?is arc may be ( any desir$ l5g?1 & yields a s(t1 blui%-:ite light :i* is a ne> approa* to daylight4 ,! ,telegraph ,! ne$ ( "s means ( giv+ signals at a di/ance 0 e>ly felt 9 ! art ( w>4 ,flag signals su* z are n[ us$ by ! armies & navies ( ! _w 7 introduc$ 9 ! middle ( ! sev5te5? c5tury by ! ,duke ( ,york1 admiral ( ! ,engli% fleet1 :o aft]w>d became ,james ,,ii4 ( ,engl&4 ,o!r me?ods ( communicat+ at a di/ance 7 devis$ f "t to "t1 b ! di/ance 0 only t at :i* a signal c\ld be se5 or a s\nd he>d4 ,no means ( communicat+ ov] v long di/ances 0 possible until ! magnetic action ( an electric curr5t 0 discov]$4 ,:5 ,o]/$'s discov]y 0 made kn[n m5 began to ?9k ( signall+ to a di/ance by means ( ! action ( an electric curr5t on a magnetic ne$le4 ,a curr5t may be s5t ov] a v long wire1 & x w deflect a magnetic ne$le at ! o!r end4 ,! movem5ts ( ! ne$le may be controll$ by op5+ & clos+ ! circuit1 & a sy/em ( signals or an alphabet may be arrang$4 ,a numb] ( ne$le telegraphs 7 inv5t$1 b !y 7 too sl[ 9 action4 ,two o!r great inv5tions 7 ne$$ to prep>e ! way = ! telegraph4 ,"o 0 ! electromagnet 9 ! =m develop$ by ,pr(essor ,h5ry1 a horse%oe magnet ) _m turns ( silk-cov]$ wire ar\nd ! s(t-iron core1 s t a v feeble curr5t w produce a magnet /rong en\gh to move an armature ( s(t iron4 ,! magnet has ?is /r5g? because ! curr5t fl[s s _m times ar\nd ! iron core4 ,ano!r ne$ 0 t ( a batt]y t c\ld be dep5d$ on to give a con/ant curr5t = a consid]able l5g? ( "t4 ,?is ne$ 0 met by ! ,daniell cell4 ,! electromagnet made ! telegraph possible4 ,! locomotive made x a necessity4 ,)\t ! telegraph x w\ld be impossible to control a railway sy/em f a c5tral (fice4 ,a tra9 aft] leav+ ! c5tral /ation w\ld be l a %ip at sea be=e ! inv5tion ( ! wireless telegraph4 ,no?+ c\ld be kn[n ( its movem5ts until x return$4 ,! ne$ ( a telegraph 0 ke5ly felt 9 ,am]ica :5 ! new republic 0 ext5d$ to ! ,pacific ,coa/4 ,an ,engli% /atesman said1 aft] ! ,unit$ ,/ates acquir$ ,cali=nia1 t ?is m>k$ ! end ( ! great ,am]ican ,republic1 = a p spread ov] su* a va/ area & sep>at$ by su* natural b>ri]s c\ld n hold toge!r4 ,he did n "k t ! iron wire ( ! telegraph w\ld b9d ! new nation firmly toge!r4 ,! ,morse telegraph sy/em n[ 9 use ?r\gh\t ! civiliz$ _w 0 made possible by ! "w ( ,/urgeon & ,h5ry4 ,/urgeon's electromagnet might h be5 us$ = telegraphy ?r\gh v %ort di/ances1 b ,h5ry's magnet1 ) its coils ( _m turns ( insulat$ wire1 0 ne$$ = long-di/ance signall+4 ,9 "o ( ! rooms ( ! ,albany ,academy1 ,pr(essor ,h5ry caus$ an electromagnet to s\nd a bell :5 ! curr5t 0 transmitt$ ?r\gh m ?an a mile ( wire4 ,?is might be call$ ! fir/ electromagnetic telegraph4 ,b ! application to actual practice 0 made by ,morse1 & ! man :o fir/ makes ! practical application ( a pr9ciple is ! true inv5tor4 ,9 #ahcb1 on bo>d ! packet-%ip ,sully1 ,samuel ,f4 ,b4 ,morse1 an ,am]ican arti/1 =ty-"o ye>s ( age1 0 return+ f ,europe4 ,9 conv]sation a ,doctor ,jackson ref]r$ to ! electrical exp]im5ts ( ,ampre1 :i* he _h witness$ :ile 9 ,europe1 &1 9 reply to a "q1 said t electricity passes in/antane\sly ov] any kn[n l5g? ( wire4 ,! ?\ght ( transmitt+ words by means ( ! electric curr5t at once took possession ( ! arti/'s m9d4 ,aft] _m days & sleepless nights he %[$ to fri5ds on bo>d ! draw+s & notes he _h made ( a record+ telegraph4 ,9 ,new ,york1 9 a room provid$ by 8 bro!rs1 he gave himself up to ! work+-out ( 8 idea1 sleep+ little & eat+ ! simple/ food4 ,receiv+ an appo9tm5t z pr(essor 9 ! ,univ]sity ( ! ,city ( ,new ,york1 he mov$ to "o ( ! build+s ( t univ]sity & cont9u$ 8 exp]im5ts 9 extreme pov]ty1 & at times fac+ />vation1 z 8 sal>y dep5d$ on ! tuition fees ( 8 pupils4 ,a /ory told by "o ( 8 pupils describes 8 condition at ! "t4 ,i engag$ to become "o ( ,morse's pupils4 ,he _h ?ree o!rs4 ,i soon f\nd t ! pr(essor _h little patronage4 ,i paid my fifty doll>s2 t settl$ "o qu>t]'s tuition4 ,i rememb]1 :5 ! second 0 due1 my remittance f home did n come z expect$1 & "o day ! pr(essor came 9 & said1 c\rte\sly3 ',well1 ,/ro!r1 my boy1 h[ are we (f = money8' ',:y1 pr(essor1 ,i am sorry to say ,i h be5 disappo9t$2 b ,i expect a remittance next week4' ',next week6' he repeat$1 sadly2 ',i %all be dead by t "t4' ',dead1 sir8' ',yes2 dead by />vation6' ,i 0 di/ress$ & a/oni%$4 ,i said1 hurri$ly3 ',w\ld t5 doll>s be ( any s]vice8' ',t5 doll>s w\ld save my life2 t is all x w\ld d4' ,! money 0 paid1 all ! /ud5t _h1 & ! two d9$ toge!r4 ,x 0 ,morse's fir/ meal 9 tw5ty-f\r h\rs4 ,! ,morse telegraph s\nd] 7,fig4 #fa7 consi/s ( an electromagnet & a s(t-iron armature4 ,:5 no curr5t is fl[+ ! armature is held away f ! magnet by a spr+4 ,:5 ! circuit is clos$ a curr5t fl[s ?r\gh ! coils ( ! magnet & ! armature is attract$1 caus+ a click4 ,:5 ! circuit is brok5 ! spr+ pulls ! armature away f ! magnet1 caus+ ano!r click4 ,! circuit is made & brok5 by means ( a key at ! o!r end ( ! l9e4 ,9 ,morse's fir/ in/rum5t 7,fig4 #fb7 ! armature c>ri$ a p51 :i* 0 drawn across a ribbon ( pap] :5 ! armature 0 attract$ by ! magnet4 ,if ! p5 0 held by ! magnet = a v %ort "t1 a dot 0 made2 if = a long] "t1 a da%4 ,! p5 0 soon disc>d$1 & ! message tak5 by s\nd only4 ,! ,morse alphabet n[ 9 use 0 devis$ by a ,mr4 ,vail1 :o assi/$ ,morse 9 develop+ ! telegraph4 ,! ?\ght occurr$ to ,mr4 ,vail t he c\ld get help f a pr9t+-(fice 9 decid+ ! comb9ations ( dots & da%es t %\ld be us$ = ! diff]5t lett]s4 ,! lett]s requir+ ! l>ge/ spaces 9 ! type-cases are ! ones t occur mo/ frequ5tly1 & = ^! lett]s he us$ ! simple/ comb9ations ( dots & da%es4 ,illu/ration3 ,,fig4 #fa--;,a ,,telegraph ,,s\nd] ,illu/ration3 ,,fig4 #fb--,,morse',s ,,fir/ ,,telegraph ,,in/rum5t ,a p5 0 atta*$ to ! p5dulum & drawn across ! /rip ( pap] by ! action ( ! electromagnet4 ,! lead type %[n 9 ! l[] "r-h& corn] 0 us$ 9 mak+ electrical contact :5 s5d+ a message4 ,! mod]n in/rum5t %[n 9 ! l[] left-h& corn] is ! "o t s5t a message ar\nd ! _w 9 #ahif4 ,photo by ,claudy4 ,morse repeat$ly said t1 if he c\ld make 8 telegraph "w ?r\gh t5 miles1 he c\ld make x "w ar\nd ! _w4 ,?is promise ( long-di/ance telegraphy he fulfill$ by ! use ( ! relay4 ,! relay works 9 ! same way z ! s\nd]4 ,! curr5t com+ ov] a long l9e may be too feeble to produce a click t c be easily he>d1 yet /rong en\gh to magnetize ! coils ( ! relay & cause ! armature to close ano!r circuit4 ,?is second circuit includes ! s\nd] & a batt]y 9 ! same /ation z ! s\nd]1 :i* we %all call ! local batt]y4 ,! relay simply acts z a contact key1 & closes ! circuit ( ! local batt]y4 ,?us ! curr5t f ! local batt]y fl[s ?r\gh ! s\nd] & produces a l\d click4 ,sometimes a relay is us$ to control a second v long circuit4 ,at ! f>!r end ( ! second circuit may be a s\nd] or a second relay :i* controls a ?ird circuit4 ,any numb] ( circuits may be ?us connect$ by means ( relays4 ,?is is a =m ( repeat+ sy/em us$ = telegraph+ ov] v long di/ances4 ,fig4 #fc %[s a circuit ) relay & s\nd]4 ,illu/ration3 ,,fig4 #fc--;,a ,,telegraphic ,,circuit ,,) ,,relay ,,& ,,s\nd] ,9 ! telegraphic circuit only "o connect+ wire is ne$$4 ,! e>?1 be+ a good conductor ( electricity1 is us$ z "p ( ! circuit4 ,x is necess>y1 !re=e1 to make a gr\nd connection at ea* end ( ! l9e1 ! in/rum5ts be+ connect$ betwe5 ! l9e wire & ! e>?4 ,= long-di/ance telegraphy a curr5t f a dynamo is us$ in/ead ( a batt]y curr5t4 ,fig4 #fd %[s a simple telegraphic circuit4 ,illu/ration3 ,,fig4 #fd--;,a ,,simple ,,telegraphic ,,circuit ,two keys are %[n at ,k ,k1 & two swit*es at ,s ,s4 ,:5 "o key is to be us$ ! swit* at t /ation mu/ be op51 & ! swit* at ! o!r /ation clos$4 ,a telegraphic message travels ) ! spe$ ( light1 = ! spe$ ( electricity & ! spe$ ( light are ! same4 ,a telegraphic signal w\ld g m ?an sev5 times ar\nd ! e>? 9 "o second if x travell$ on "o cont9u\s wire4 ,! relays t mu/ be us$1 h[ev]1 cause "s delay4 ,9 #ahce ,morse's exp]im5tal telegraph 0 complet$1 & 9 #ahcg x 0 exhibit$ to ! public1 b sev5 ye>s m pass$ be=e a l9e 0 e/abli%$ = public use4 ,aid f ,congress 0 necess>y4 ,go+ to ,wa%+ton1 ,morse exhibit$ 8 in/rum5t 9 ! halls ( ! ,capitol1 s5d+ messages ?r\gh t5 miles ( wire w\nd on a reel4 ,! inv5tion 0 ridicul$1 b ! inv5tor did n despair4 ,a bill = an appropriation to e/abli% a telegraphic l9e betwe5 ,wa%+ton & ,baltimore pass$ ! ,h\se by a small majority4 ,! la/ day ( ! session came4 ,t5 o'clock at night1 two h\rs be=e adj\rnm5t1 & ! ,s5ate _h n act$4 ,a s5ator advis$ ,morse to g home & ?9k no m ( x1 say+ t ! ,s5ate 0 n 9 sympa?y ) 8 project4 ,he w5t to 8 hotel1 c\nt$ 8 money1 & f\nd t he c\ld pay 8 bill1 buy 8 ticket home1 & h ?irty-sev5 c5ts left4 ,all ?r\gh 8 "w he _h firmly believ$ t a ,high] ,p[] 0 direct+ 8 "w1 & br++ to ! _w1 ?r\gh 8 inv5tion1 a new & uplift+ =ce2 & s :5 all seem$ lo/ he did n lose he>t4 ,9 ! morn+ a fri5d1 ,miss ,ellswor?1 call$ & (f]$ h] congratulations t ! bill _h be5 pass$ by ! ,s5ate & ?irty ?\s& doll>s appropriat$ = ! telegraph4 ,be+ ! fir/ to br+ ! news ( 8 success1 ,mr4 ,morse promis$ h] t ! fir/ message ov] ! new l9e %\ld be h]s4 ,9 ab\t a ye> ! l9e 0 complet$1 & ,miss ,ellswor? dictat$ ! n[ fam\s message3 ,:at ha? ,god wr\ght6 ,soon aft]w>d ! ,democratic ,conv5tion1 9 session 9 ,baltimore1 receiv$ a telegraphic message f ,s5ator ,silas ,wright1 9 ,wa%+ton1 decl9+ ! nom9ation = ! ,vice-,presid5cy1 :i* _h be5 t5d]$ him4 ,! conv5tion refus$ to accept a message s5t by telegraph1 & s5t a committee to ,wa%+ton to inve/igate4 ,! message 0 confirm$1 & ,morse & 8 telegraph became fam\s4 ,fig4 #fe %[s ! fir/ telegraph in/rum5t us$ = comm]cial "w4 ,illu/ration3 ,,fig4 #fe--;,,fir/ ,,telegraph ,,in/rum5t ,,us$ ,,= ,,comm]cial ,,"w ,photo by ,claudy4 ,! desire to telegraph across ! ocean came ) ! introduction ( ! telegraph on l&4 ,b>e wires 9 ! air ) glass insulators at ! poles are us$ = l& telegraphy1 b b>e wires 9 ! wat] c\ld n be us$1 = ocean wat] w conduct electricity4 ,some?+ 0 ne$$ to cov] ! wire1 protect x f ! wat]1 & prev5t ! escape ( ! electric curr5t4 ,j :5 x 0 ne$$ su* a sub/ance 0 discov]$4 ,9 #ahdc1 :5 ,morse 0 work+ on 8 telegraph1 x 0 f\nd t ! juice ( a c]ta9 k9d ( tree gr[+ 9 ! ,malayan ,ar*ipelago =m$ a sub/ance some:at l rubb] b m durable1 & especially suit$ to ! insulation ( wires 9 wat]4 ,?is sub/ance is gutta-p]*a4 ,ocean cables are made ( a numb] ( copp] wires1 ea* wire cov]$ ) gutta-p]*a1 ! wires twi/$ toge!r & protect$ ) t>r$ rope y>n & an out] lay] ( galvaniz$ iron wires4 ,! e>? is us$ = ! return circuit1 z 9 ! l& telegraph4 ,duplex ,telegraphy ,! telegraph 0 a success1 b _m improvem5ts 7 yet to be made4 ,economy ( con/ruction 0 ! ?+ s\ght =4 ,to make "o wire d ! "w ( two 0 accompli%$ by ! inv5tion ( ! duplex sy/em4 ,9 duplex telegraphy two messages may be s5t 9 opposite directions ov] ! same wire at ! same "t4 ,let u take a look at "s ( ! me?ods by :i* ?is is accompli%$4 ,"o me?od ) a long "n b v simple 9 its work+ is ! diff]5tial sy/em 7,fig4 #ff74 ,9 ! diff]5tial sy/em ! curr5t f ! home batt]y divides into two bran*es pass+ ar\nd ! coils ( ! electromagnet 9 opposite directions4 ,n[ if ^! two bran*es are s arrang$ t ! curr5ts fl[+ ?r\gh !m are equal1 ! relay w n be magnetiz$1 because "o curr5t w\ld t5d to make ! end ,a a nor? pole1 & ! o!r curr5t w\ld t5d to make ! same end a s\? pole4 ,! result is t ! relay coil is n magnetiz$1 & does n attract ! armature4 ,b ! curr5t f ! di/ant batt]y comes ov] "o ( ^! bran*es only1 & w magnetize ! relay4 ,h5ce1 ) a simil> arrangem5t at ! second /ation1 two messages may be s5t at ! same "t 9 opposite directions4 ,illu/ration3 ,,fig4 #ff--;,,h[ ,,two ,,messages ,,are ,,s5t ,,ov] ,,"o ,,wire ,,at ,,! ,,same ,,"t ,ano!r me?od n q s simple 9 pr9ciple is ! bridge me?od4 ,:5 ! key at /ation ,a 7see ,fig4 #fg7 is clos$1 ! curr5t f ! batt]y at /ation ,a divides at ,c1 & if ! resi/ances #a & #b are equal1 & ! resi/ance #c is equal to ! resi/ance ( ! l9e1 no curr5t w fl[ ?r\gh ! s\nd]4 ,b if a curr5t comes ov] ! l9e f ! di/ant /ation ?is curr5t divides at ,d1 & a "p goes ?r\gh ! s\nd]1 caus+ x to click4 ,! s\nd] is n affect$1 !re=e1 by ! curr5t f ! home batt]y1 b is affect$ by ! curr5t f ! di/ant batt]y4 ,!re=e1 a message may be s5t & ano!r receiv$ at ! same "t4 ,if !re is a simil> arrangem5t at ! o!r /ation1 two messages may travel ov] ! l9e 9 opposite directions at ! same "t4 ,illu/ration3 ,,fig4 #fg--;,,h[ ,,two ,,messages ,,are ,,s5t ,,ov] ,,"o ,,wire ,,at ,,! ,,same ,,"t4 ,,bridge ,,me?od ,! diff]5tial me?od is us$ 9 l& telegraphy1 ! bridge me?od almo/ exclusively 9 subm>9e telegraphy4 ,! next /ep 0 a quadruplex sy/em1 by means ( :i* f\r messages may be transmitt$ ov] "o wire at ! same "t4 ,! fir/ quadruplex sy/em 0 inv5t$ by ,edison 9 #ahgd1 & 9 f\r ye>s x sav$ m ?an half a million doll>s4 ,o!r sy/ems h be5 inv5t$ :i* make x possible to s5d ev5 a l>g] numb] ( messages at "o "t ov] a s+le wire4 ,! ,telephone ,! idea ( talk+ by telegraph began to gr[ 9 ! m9ds ( inv5tors soon aft] ! ,morse in/rum5t came into use4 ,! s\nd ( ! voice causes vibrations 9 ! air4 7,?is is simply %[n 9 ! /r+ telephone4 ,?is telephone is made by /ret*+ a ?9 membrane1 su* z ?9 %eepsk91 or gold-beat]s' sk91 ov] a r\nd frame ( wood or metal4 ,two su* in/rum5ts are connect$ by a /r+1 ! end ( ! /r+ be+ fa/5$ to ! middle ( ! /ret*$ membrane4 ,! s\nd ( ! voice causes ?is membrane to vibrate4 ,z ! membrane moves rapidly back & =?1 x pulls & releases ! /r+1 & s causes ! membrane at ! o!r end to vibrate & give out ! s\nd4 ,?is is ! actual c>ry+ ( ! s\nd vibrations along ! /r+47 ,9 ! telephone x is n s\nd vibrations b an electric curr5t t travels ov] ! l9e wire4 ,! telephone message1 !re=e1 travels ) ! spe$ ( electricity1 n ) ! spe$ ( s\nd4 ,if x travell$ ) ! spe$ ( s\nd 9 air1 a message spok5 9 ,*icago w\ld be he>d 9 ,new ,york "o h\r lat]2 b we "k t a message spok5 9 ,*icago may be he>d 9 ,new ,york ! in/ant x is spok54 ,! telephone1 l ! telegraph1 dep5ds on ! electromagnet4 ,! ?\ght ( inv5tors at fir/ 0 to make ! vibrations ( a ?9 membrane1 caus$ by ! s\nd ( ! voice1 op5 & close a telegraphic circuit4 ,an electromagnet at ! o!r end ( ! l9e w\ld cause a ?9 membrane ) a piece ( s(t iron atta*$ to x to vibrate1 j z ! magnet 9 ! telegraph receiv] pulls & releases ! s(t-iron armature z ! circuit is made & brok54 ,! ?9 membrane caus$ to vibrate 9 ?is way w\ld give out ! s\nd4 ,a telephone on ?is pr9ciple 0 inv5t$ by ,philip ,reis1 a s*oolma/] 9 ,g]many4 ,! transmitt] 0 c>v$ out ( wood 9 ! %ape ( a human e>1 ! ?9 membrane be+ 9 ! position ( ! e>-drum4 ,musical s\nds & ev5 words 7 transmitt$ by ?is telephone1 b x c\ld nev] h be5 successful z a practical work+ telephone4 ,! membrane 9 ! receiv] w\ld vibrate ) ! same spe$ z ! membrane 9 ! transmitt]1 b s\nd dep5ds on some?+ m ?an spe$ ( vibration4 ,! ,bell telephone1 z kn[n to-day1 began ) a /udy ( ! human e>4 ,alex&] ,graham ,bell 0 a tea*] ( ! deaf4 ,8 aim 0 to tea* ! deaf to use spok5 language1 & = ?is purpose he wi%$ to le>n ! nature ( ! vibrations caus$ by ! voice4 ,8 plan 0 to cause ! e> itself to trace on smok$ glass ! waves produc$ by ! diff]5t lett]s ( ! alphabet1 & to use ^! trac+s 9 tea*+ ! deaf4 ,accord+ly1 a human e> 0 m\nt$ on a suitable support1 ! /irrup-bone remov$1 leav+ two bones atta*$1 & a /ylus ( :eat /raw atta*$ to "o ( ! bones4 ,! e>-drum1 caus$ to vibrate by ! s\nd1 mov$ ! two small bones & ! po9t] ( /raw1 s t :5 he sang or talk$ to ! e> delicate trac+s 7 made on ! glass4 ,?is exp]im5t sugge/$ to ,mr4 ,bell t a membrane heavi] ?an ! e>-drum w\ld move a heavi] weight4 ,if ! e>-drum1 no ?ick] ?an tissue-pap]1 c\ld move ! bones ( ! e>1 a heavi] membrane might vibrate a piece ( iron 9 front ( an electromagnet4 ,he 0 at ! same "t devis+ a telegraph = transmitt+ messages by means ( musical s\nds4 ,9 ?is telegraph he 0 us+ an electromagnet 9 ! transmitt] & ano!r electromagnet 9 ! receiv]4 ,he atta*$ ! s(t-iron armature ( ea* electromagnet to a /ret*$ membrane ( gold-beat]s' sk91 expect+ t ! s\nd ( 8 voice w\ld cause ! membrane ( ! transmitt] to vibrate1 & t1 by means ( ! electromagnets1 ! membrane ( ! receiv] w\ld be made to vibrate 9 ! same way 7,fig4 #fh74 ,at fir/ he 0 disappo9t$1 b aft] mak+ "s *anges 9 ! armatures a di/9ct s\nd 0 he>d 9 ! receiv]4 ,lat] ! membrane 0 disc>d$1 & a ?9 iron disk us$ ) bett] effect4 ,illu/ration3 ,,fig4 #fh--;,,fir/ ,,bell ,,telephone ,,receiv] ,,& ,,transmitt] ,! receiv] is on ! left 9 ! picture4 ,a ?9 membrane ( gold-beat]s' sk9 tightly /ret*$ & fa/5$ ) a cord c be se5 on ! end ( ! transmitt] & ( ! receiv]4 ,an electromagnet is also %[n ov] ea* membrane4 ,?is ?9 membrane1 ) a piece ( s(t iron atta*$1 0 us$ 9 place ( ! s(t-iron disk ( ! mod]n receiv]4 ,! /ory ( ,bell's /ruggles might seem l ! repetition ( ! life /ory ( _m ano!r great inv5tor4 ,he knew t he _h discov]$ some?+ ( great value to ! _w4 ,he devot$ 8 "t to ! p]fect+ ( ! telephone1 neglect+ 8 pr(essional "w & f9ally giv+ x up1 t he might give 8 :ole "t to 8 inv5tion4 ,he 0 =c$ to endure pov]ty & ridicule4 ,he 0 call$ a crank :o says he c talk ?r\gh a wire4 ,m5 said 8 inv5tion c\ld nev] be made practical4 ,ev5 aft] he succe$$ 9 f9d+ a few pur*as]s & "s ( ! telephones 7 9 actual use1 p 7 sl[ to adopt x4 ,! idea ( talk+ at a piece ( iron & he>+ ano!r piece ( iron talk seem$ l a k9d ( wit*craft4 ,9 ! telephone we see ano!r use ( ! electromagnet4 ,a v ?9 iron disk ne> ! poles ( an electromagnet =ms ! telephone receiv] 7,fig4 #fi74 ,an electric curr5t travels ov] ! telephone wire4 ,if ! curr5t gr[s /rong]1 ! magnet is made /rong] & pulls ! disk t[>d x4 ,if ! curr5t gr[s weak]1 ! magnet becomes weak] & does n pull s h>d on ! disk4 ,! disk !n spr+s back f ! magnet4 ,if ^! *anges take place rapidly ! disk moves back & =? rapidly & gives out a s\nd4 ,! s\nd ( ! voice at ! o!r end ( ! l9e sets ! disk 9 ! m\?piece vibrat+4 ,! vibrations ( ?is disk cause ! *anges 9 ! electric curr5t fl[+ ov] ! l9e-wire1 & ! *anges 9 ! electric curr5t cause ! disk ( ! receiv] to vibrate 9 exactly ! same way z ! disk at ! m\?piece4 ,?us ! words spok5 into ! m\?piece may be he>d at ! receiv]4 ,illu/ration3 ,,fig4 #fi--;,a ,,telephone ,,receiv] ,! transmitt] us$ by ,bell 0 l ! receiv]4 ,two receiv]s f ! common telephone connect$ by two wires may be us$ z a telephone )\t batt]ies4 ,fig4 #gj %[s a complete telephone made ( two receiv]s connect$ by two wires4 ,! disk 9 "o receiv] :i* is n[ us$ z a transmitt] is made to vibrate by ! s\nd ( ! voice4 ,n[ :5 a piece ( iron moves back & =? 9 a magnetic field x /r5g!ns & weak5s ! field4 ,s ! magnetic field 9 ! transmitt] is rapidly *ang$ by ! movem5t ( ! iron disk4 ,n[ we h f\nd t :5ev] a coil ( wire is 9 a *ang+ magnetic field a curr5t is induc$ 9 ! coil4 ,! small coil 9 ! transmitt]1 !re=e1 has a curr5t induc$ 9 x4 ,we h also f\nd t :5 ! magnetic field is made /rong] ! induc$ curr5t fl[s 9 "o direction1 & :5 ! field is made weak] ! curr5t fl[s 9 ! opposite direction4 ,s9ce ! field 9 ! transmitt] is made alt]nately /rong] & weak]1 ! curr5t 9 ! coil fl[s fir/ 9 "o direction1 !n 9 ! opposite direction--t is1 we h an alt]nat+ curr5t4 ,?is alt]nat+ curr5t1 ( c\rse1 fl[s ov] ! l9e-wire & ?r\gh ! coil 9 ! receiv]4 ,9 ! receiv] ! alt]nat+ curr5t w alt]nately /r5g!n & weak5 ! magnetic field1 & z x does s ! pull ( ! magnet on ! iron disk is /r5g!n$ & weak5$4 ,! iron disk 9 ! receiv]1 !re=e1 vibrates 9 exactly ! same way z ! disk 9 ! transmitt]1 & s gives out a s\nd j l t :i* is act+ on ! transmitt]4 ,illu/ration3 ,,fig4 #gj--,,two ,,receiv]s ,,us$ ,,z ,a ,,complete ,,telephone ,9 ! ,blake transmitt]1 :i* is n[ commonly us$1 ! disk moves a p5cil ( c>bon :i* presses aga9/ ano!r p5cil ( c>bon4 ,?is v>ies ! pressure betwe5 ! two p5cils ( c>bon4 ,a batt]y curr5t fl[s ?r\gh ! two c>bons1 & z ! pressure ( ! c>bons *anges ! /r5g? ( ! curr5t *anges4 ,:5 ! c>bons are press$ toge!r m closely ! curr5t is /rong]4 ,:5 ! pressure is less ! curr5t is weak]4 ,we h1 !n1 a v>y+ curr5t ?r\gh ! c>bons4 ,?is curr5t fl[s ?r\gh ! prim>y coil ( an induction-coil1 ! second>y be+ connect$ to ! l9e-wire4 ,n[ a curr5t ( v>y+ /r5g? 9 ! prim>y induces an alt]nat+ curr5t 9 ! second>y4 ,we h1 !n1 an alt]nat+ curr5t fl[+ ov] ! l9e-wire4 ,?is alt]nat+ curr5t acts on ! magnetic field ( ! receiv] 9 ! way describ$ be=e1 caus+ ! disk 9 ! receiv] to vibrate & give out ! s\nd4 ,= long-di/ance "w a c>bon-du/ transmitt] 7,fig4 #ga7 is us$4 ,9 ?is !re are _m granules ( c>bon1 s t in/ead ( two c>bon-po9ts 9 contact !re are _m4 ,?is makes ! transmitt] m s5sitive4 ,illu/ration3 ,,fig4 #ga--;,,c>bon-,,du/ ,,transmitt] ,! /r5g? ( curr5t requir$ = ! telephone is v small4 ,to transmit a telephone message requires less ?an a hundr$-million? "p ( ! curr5t requir$ = a telegraphic message4 ,! "w done 9 lift+ ! telephone receiv] a di/ance ( "o foot1 if *ang$ into an alt]nat+ curr5t1 w\ld be suffici5t to keep up a s\nd 9 ! receiv] = a hundr$ ?\s& ye>s4 ,because ( its extreme s5sitiv5ess ! telephone requires a complete wire circuit4 ,! e>? _c be us$ = ! return circuit1 z 9 ! case ( ! telegraph4 ,di/urbances 9 ! e>?1 vibration1 leakage curr5ts f trolley l9es1 & s =?1 w\ld int]f]e s]i\sly ) ! action ( ! telephone4 ,:5 ! telephone 0 inv5t$ x 0 commonly rem>k$ t x c\ld n take ! place ( ! telegraph 9 comm]ce1 = ! latt] gave ! m]*ant "s evid5ce ( a bus9ess transaction1 :ile ! telephone left no sign4 ,!re 0 a "t :5 m5 fe>$ to tru/ ea* o!r1 b n[ l>ge bus9ess deals are made by telephone2 products ( ! f>m1 ! factory1 & ! m9e are b\ght & sold 9 imm5se quantities )\t a writt5 contract or ev5 ! writt5 evid5ce ( a telegram4 ,?us ! telephone has develop$ a _s ( bus9ess honor4 ,! ,phonograph ,! phonograph grew out ( ! telephone4 ,x is said to be ! only "o ( ,edison's inv5tions t came by accid5t1 yet only a man ( g5ius w\ld h se5 ! mean+ ( su* an accid5t4 ,he 0 s++ into ! m\?piece ( a telephone :5 ! vibrations ( ! disk caus$ a f9e /eel po9t to pi]ce "o ( 8 f+]s held j beh9d ! disk4 ,?is set him to ?9k+4 ,if ! s\nd ( 8 voice c\ld cause ! disk to vibrate ) =ce en\gh to pi]ce ! sk91 w\ld x n make impressions on t9-foil1 & s make a record ( ! voice t c\ld be reproduc$ by pass+ ! po9t rapidly ov] ! same impressions8 ,he gave 8 assi/ants ! necess>y in/ructions1 & soon ! fir/ phonograph 0 made4 ,?is disk 9 ! phonograph is set 9 vibration by s\nd vibrations 9 ! air 9 ! same way z ! disk 9 ! telephone transmitt]4 ,atta*$ to ! disk is a ne$le-po9t :i*1 ( c\rse1 vibrates ) ! disk4 ,if a cyl9d] ) a s(t surface is turn$ rapidly "u ! /eel po9t z x vibrates1 impressions are made 9 ! cyl9d] correspond+ to ! movem5ts ( ! disk4 ,! cyl9d] mu/ move =w>d z x turns1 s t its pa? w be a spiral4 ,if1 n[1 ! /ylus is plac$ at ! />t+-po9t & ! cyl9d] turn$ rapidly ! /ylus w move rapidly up & d[n z x goes ov] ! ind5tations 9 ! cyl9d]1 & s cause ! metal disk to vibrate & give out a s\nd l t receiv$ at fir/4 ,9 ! e>lie/ phonographs ! cyl9d] 0 cov]$ ) t9-foil4 ,lat] ! s-call$ wax records came into use4 ,^! cyl9d]s are n made ( wax1 b ( v h>d soap4 ,fig4 #gb %[s an in/rum5t 9 :i* ! s\nd ( ! voice caus$ a p5cil-po9t to trace a wavy l9e on a cyl9d]4 ,?is in/rum5t may be call$ a =]unn] ( ! phonograph4 ,fig4 #gc %[s ,edison's fir/ phonograph ) a mod]n in/rum5t plac$ beside x = comp>ison4 ,illu/ration3 ,,fig4 #gb--,,! ,,phonautograph1 ,a ,,=]unn] ,,( ,,! ,,phonograph ,illu/ration3 ,,fig4 #gc ,,edison',s ,,fir/ ,,phonograph ,,& ,a ,,mod]n ,,in/rum5t ,photo by ,claudy4 ,gas-,eng9es ,cannons are ! olde/ gas-eng9es4 ,inde$1 ! pr9ciple ( ! cannon is ! same z t ( ! mod]n gas-eng9e1 ! pi/on 9 ! eng9e tak+ ! place ( ! cannon-ball4 ,! p[] 9 ea* case is obta9$ by explosion--9 ! cannon ! explosion ( p[d]1 9 ! eng9e ! explosion ( a mixture ( air & gas4 ,p[d]-eng9es ) pi/ons 7 propos$ 9 ! sev5te5? c5tury1 & "s 7 actually built1 b x prov$ too difficult to control !m1 & ! idea ( ! gas-eng9e 0 ab&on$ = m ?an a hundr$ ye>s4 ,! discov]y ( coal-gas ne> ! close ( ! eighte5? c5tury gave a new impetus to ! gas-eng9e4 ,john ,b>b]1 an ,engli%man1 built ! fir/ actual gas-eng9e4 ,he us$ gas di/ill$ f wood1 coal1 or oil4 ,! gas1 mix$ ) ! prop] proportion ( air1 0 introduc$ into a tank :i* he call$ ! explod]4 ,! mixture 0 fir$ & issu$ out 9 a cont9u\s /ream ( flame aga9/ ! vanes ( a paddle-:eel1 driv+ !m r\nd ) great =ce4 ,9 #ahjd ,lebon1 a ,fr5* eng9e]1 0 assass9at$1 & ! progress ( ! gas-eng9e set back a numb] ( ye>s1 = ?is eng9e] _h propos$ to compress ! mixture ( gas & air be=e fir+1 & to fire ! mixture by an electric sp>k4 ,?is is ! me?od us$ 9 gas-eng9es to-day4 ,! fir/ practical work+ gas-eng9e 0 inv5t$ by ,l5oir1 a ,fr5*man1 9 #ahfj4 ,f ?is "t to ! end ( ! c5tury ! gas-eng9e develop$ rapidly1 receiv+ a new impulse f ! increas+ dem& = ! motor-c>4 ,! eng9e ( ! ,g]man inv5tors1 ,otto & ,lang51 br\ght out 9 #ahgf1 m>k$ ! beg9n+ ( a new era4 ,! great] numb] ( eng9es us$ 9 automobiles to-day are ( ! k9d kn[n z ! ,otto cycle1 or f\r-cycle1 eng9e4 ,?is eng9e is call$ f\r-cycle because ! pi/on makes f\r /rokes = e explosion4 ,!re is "o /roke to admit ! mixture ( gas & air to ! cyl9d]1 ano!r to compress ! gas & air1 at ! beg9n+ ( ! ?ird /roke ! explosion takes place1 & 9 ! f\r? /roke ! burn$-out gases are driv5 out ( ! cyl9d]4 ,! work+ ( ! f\r-cycle gas-eng9e is made cle> 9 ,figs4 #gd1 #ge1 #gf1 & #gg4 ,illu/ration3 ,,fig4 #gd--;,,fir/ ,,/roke4 ,,gas ,,& ,,air ,,admitt$ ,,to ,,! ,,cyl9d] ,illu/ration3 ,,fig4 #ge--,,second ,,/roke4 ,,mixture ,,( ,,gas ,,& ,,air ,,compress$ ,illu/ration3 ,,fig4 #gf--,,?ird ,,/roke4 ,,! ,,mixture ,,is ,,explod$ ,,& ,,exp&s1 ,,driv+ ,,! ,,pi/on ,,=w>d ,illu/ration3 ,,fig4 #gg--;,,f\r? ,,/roke1 ,,exhau/4 ,,! ,,burn$-,,out ,,mixture ,,( ,,gas ,,& ,,air ,,expell$ ,,f ,,! ,,cyl9d] ,,! ,,f\r-,,cycle ,,gas-,,eng9e ,9 su* a gas-eng9e ! p[] is appli$ to ! pi/on only 9 "o /roke out ( e f\r1 :ile 9 ! /eam-eng9e ! p[] is appli$ at e /roke4 ,x w\ld seem1 !re=e1 t a /eam-eng9e w\ld d m "w ?an a gas-eng9e = ! same am\nt ( heat1 b su* is n ! case2 9 fact1 a good gas-eng9e w d ab\t twice z mu* "w z a good /eam-eng9e = ! same am\nt ( fuel4 ,! reason is t ! /eam-eng9e wa/es its heat4 ,heat is giv5 to ! cond5s]1 to ! iron ( ! boil]1 to ! connect+ pipes & ! air ar\nd !m1 :ile 9 ! gas-eng9e ! heat is produc$ 9 ! cyl9d] by ! explosion & ! p[] appli$ directly to ! pi/on-head4 ,m ?an ?is1 a /eam-eng9e :5 at re/ wa/es heat2 !re mu/ be a fire "u ! boil] if ! eng9e is to be ready = use on %ort notice4 ,:5 a gas-eng9e is at re/ !re is no fire1 no?+ is be+ us$ up1 & yet ! eng9e c be />t$ v quickly4 ,a gas-eng9e c be made mu* light] ?an a /eam-eng9e ( ! same horse-p[]4 ,! automobile & ! fly+-ma*9e require v light eng9es4 ,)\t ! gas-eng9e ! automobile w\ld h rema9$ imp]fect & crude1 :ile ! fly+-ma*9e w\ld h be5 impossible4 ,9 a two-cycle gas-eng9e !re is an explosion = e two /rokes ( ! pi/on1 or "o explosion = e revolution ( ! crank-%aft4 ,dur+ "o /roke ! mixture ( gas & air on "o side ( ! pi/on is compress$ & a new mixture ent]s on ! opposite side ( ! pi/on4 ,at ! end ( ?is /roke ! compress$ mixture is explod$1 & p[] is appli$ to ! pi/on dur+ ab\t "o-f\r? ( ! next /roke4 ,dur+ ! rema9d] ( ! second /roke ! burn$-out gas escapes1 & ! fre% mixture passes ov] f "o side ( ! pi/on to ! o!r ready = compression4 ,! two-cycle eng9e is simpl] 9 con/ruction ?an ! f\r-cycle1 hav+ no valves4 ,x also has less weight p] horse-p[]4 ,! cyl9d] ( a two-cycle eng9e is %[n 9 ,fig4 #gh4 ,illu/ration3 ,,fig4 #gh--,,two-,,cycle ,,gas-,,eng9e4 ,,crank ,,& ,,connect+-,,rod ,,are ,,enclos$ ,,) ,,! ,,pi/on ,a /eam-eng9e is self-/>t+4 ,! eng9e] has only to turn ! /eam into ! cyl9d]1 b ! gas-eng9e requires to be turn$ until at lea/ "o explosion takes place1 = until !re is an explosion ( gas & air 9 ! cyl9d] !re is no p[]4 ,a gas-eng9e may h a numb] ( cyl9d]s4 ,f\r-cyl9d] & six-cyl9d] eng9es are common4 ,9 a f\r-cyl9d]1 f\r-cycle eng9e1 :ile "o cyl9d] is on ! p[] /roke ! next is on ! compression /roke1 ! ?ird on ! admission /roke1 & ! f\r? on ! exhau/ /roke4 ,fig4 #gi %[s ! ,seld5 explosion buggy propell$ by a gas-eng9e4 ,?is ma*9e 0 ! =]unn] ( ! mod]n automobile4 ,illu/ration3 ,,fig4 #gi--,,seld5 ,,explosion ,,buggy4 ,,=]unn] ,,( ,,! ,,mod]n ,,automobile ,! ,/eam ,locomotive ,late 9 ! eighte5? c5tury a mis*iev\s boy put "s wat] 9 a gun-b>rel1 ramm$ d[n a tight wad1 & plac$ ! b>rel 9 ! fire ( a blacksmi?'s =ge4 ,! wad 0 ?r[n out ) a l\d report1 & ! boy's play-mate1 ,oliv] ,evans1 ?\ght he _h discov]$ a new p[]4 ,! prank ) ! gun-b>rel set "y ,evans ?9k+ ab\t ! p[] ( /eam4 ,x 0 n long until he read a description ( a ,newcom5 eng9e4 ,9 ! ,newcom5 eng9e1 y w rememb]1 x 0 ! pressure ( air1 n ! pressure ( /eam1 t lift$ ! weight4 ,evans soon set ab\t build+ an eng9e 9 :i* ! pressure ( /eam %\ld d ! "w4 ,he is sometimes call$ ! ,watt ( ,am]ica1 = he did 9 ,am]ica mu* ! same "w t ,watt did 9 ,scotl&4 ,evans built ! fir/ successful non-cond5s+ eng9e--t is1 an eng9e 9 :i* ! /eam1 aft] driv+ ! pi/on1 escapes into ! air in/ead ( into a cond5s]4 ,! non-cond5s+ eng9e made ! locomotive possible1 = a locomotive c\ld n conv5i5tly c>ry a cond5s]4 ,evans made a locomotive :i* travell$ v sl[ly4 ,he said1 h[ev]3 ,! "t w come :5 p w travel 9 /ages mov$ by /eam-eng9es f "o city to ano!r1 almo/ z fa/ z birds c fly1 fifte5 or tw5ty miles an h\r4 ,! inv5tor :o made ! fir/ successful locomotive 0 ,george ,/eph5son1 & x is wor? not+ t "o ( 8 eng9es1 ! ,rocket1 possess$ all ! elem5ts ( ! mod]n locomotive4 ,he comb9$ 9 ! ,rocket ! tubul> boil]1 ! =c$ draft1 & direct connection ( ! pi/on-rod to ! crank-p9 ( ! driv+-:eel4 ,! ,rocket 0 us$ on ! fir/ /eam railway 7! ,/ockton ,d>l+ton1 9 ,engl&71 :i* 0 op5$ 9 #ahbe4 ,!re _h be5 o!r railways = haul+ coal by means ( horses ov] iron tracks1 & o!r locomotives t travell$ ov] an ord9>y road2 b ?is 0 ! fir/ road on :i* a /eam-eng9e pull$ a load ov] an iron track1 ! fir/ real railroad4 ,fig4 #hj %[s ! ,rocket & two o!r e>ly locomotives4 ,illu/ration3 ,,fig4 #hj--,,"s ,,e>ly ,,locomotives ,! "o on ! "r is ,/eph5son's ,rocket4 ,photo by ,claudy4 ,9 ord] to build a railroad betwe5 ,liv]pool & ,man*e/] = c>ry+ bo? pass5g]s & freight x 0 necess>y to secure an act ( ,p>liam5t4 ,/eph5son 0 compell$ to und]go a sev]e cross-exam9ation by a committee ( ,p>liam5t1 :o fe>$ !re w\ld be great dang] if ! spe$ ( ! tra9s 7 z high z twelve miles an h\r4 ,he 0 ask$3 ,h y se5 a railroad t w\ld /& a spe$ ( twelve miles an h\r8 ,yes4 ,:]e8 ,any railroad t w\ld be> go+ f\r miles an h\r4 ,i mean to say t if x w\ld be> ! weight at f\r miles an h\r x w\ld be> x at twelve4 ,d y mean to say t x w\ld n require a /rong] railway to c>ry ! same weight at twelve miles an h\r8 ,i w give an answ] to t4 ,i d>e say e p]son has be5 ov] ice :5 skat+1 or se5 p]sons g ov]1 & !y "k t x w\ld be> !m bett] at a great] velocity ?an x w\ld if !y w5t sl[]2 :5 !y g quickly ! weight1 9 a measure1 ceases4 ,w\ld n t imply t ! road mu/ be p]fect8 ,x w\ld1 & ,i mean to make x p]fect4 ,= sev5 miles ! road mu/ be built ov] a peat bog into :i* a /one w\ld s9k to unkn[n dep?s4 ,to conv9ce ! committee1 h[ev]1 & secure ! act ( ,p>liam5t 0 m difficult ?an to build ! road4 ,b ,/eph5son 0 "o ( ! m5 :o d ?+s because !y nev] give up1 & ! road 0 built4 ,h[ a ,locomotive ,works ,to und]/& h[ a locomotive works1 let u consid] h[ ! /eam is produc$1 h[ x acts on ! pi/on1 & h[ x is controll$4 ,! /eam is produc$ 9 a locomotive 9 exactly ! same way t /eam is produc$ 9 a tea-kettle4 ,n[ ev]ybody kn[s t a qu>t ( wat] 9 a tea-kettle ) a wide bottom plac$ on a /ove w boil m quickly ?an ! same am\nt ( wat] 9 a tea-pot ) a n>r[ bottom4 ,! great] ! heat+-surface--t is1 ! great] ! surface ( heat$ metal 9 contact ) ! wat]--! m quickly ! wat] w boil & ! m quickly /eam c be produc$4 ,9 a locomotive ! aim is to use z l>ge a heat+-surface z possible4 ,?is is done by mak+ ! fire-box d\ble & all[+ ! wat] to circulate 9 ! space betwe5 ! inn] & out] p>ts1 except und]nea?2 also by plac+ tubes 9 ! boil] ?r\gh :i* ! heat$ gases & smoke f ! fire mu/ pass4 ,an ord9>y locomotive conta9s two hundr$ or m ( ^! tubes4 ,! wat] surr\nds ^! tubes1 & is !re=e 9 contact ) a v l>ge surface ( heat$ metal4 ,9 "s eng9es ! wat] is 9 ! tubes1 & ! heat$ gases surr\nd ! tubes4 ,! /eam z x ent]s ! cyl9d] %\ld be dry--t is1 x %\ld n conta9 drops ( wat]4 ,?is is accompli%$ by all[+ ! /eam f ! boil] to pass into a dome above ! boil]4 ,"h ! /eam1 :i* is ne>ly dry1 ent]s a /eam-pipe lead+ to ! cyl9d] 7,fig4 #ha74 ,! /eam is admitt$ to ! cyl9d] by means ( a slide-valve4 ,f ! diagram x c easily be se5 t ! valve admits /eam fir/ on "o side ( ! pi/on1 !n on ! o!r4 ,x c also be se5 t ! valve closes ! admission-port1 & s cuts (f ! /eam be=e ! pi/on has made a full /roke4 ,! /eam t is %ut up 9 ! cyl9d] cont9ues to exp& & act on ! pi/on4 ,at ! same "t ! valve op5s ! exhau/-port1 all[+ ! /eam to escape f ! o!r side ( ! pi/on2 b x closes ?is port be=e ! pi/on has q f9i%$ ! /roke4 ,! small quantity ( /eam ?us %ut up acts l a cu%ion to prev5t ! pi/on /rik+ ! end ( ! cyl9d] ) too great =ce4 ,! exhau/-/eam escapes ?r\gh a bla/-pipe into ! *imney1 drives ! air be=e x up ! *imney1 & ?us makes a great] draft ( air ?r\gh ! fire-box4 ,?is is call$ ! =c$ draft4 ,! escape ( ! exhau/-/eam causes ! puff+ ( ! locomotive j aft] />t+4 ,aft] ! eng9e is "u way ! eng9e] p>tly %uts (f ! /eam by means ( ! rev]s+ lev] & ! puff+ is less noticeable4 ,illu/ration3 ,,fig4 #ha--;,,h[ ,a ,,locomotive ,,works ,! arr[s %[ ! c\rse ( ! /eam4 ,! action ( ! /eam may be summ$ up z foll[s3 #a4 ,/eam admitt$ to ! cyl9d] 7admission74 #b4 ,valve closes admission-port 7cut-(f74 #c4 ,/eam %ut up 9 ! cyl9d] exp&s1 act+ on ! pi/on 7expansion p]iod74 #d4 ,valve op5s exhau/-port to all[ us$ /eam to escape 7exhau/74 ,! devices = controll+ ! /eam are ! ?rottle-valve & ! valve-ge>4 ,! ?rottle-valve is at ! entrance to ! /eam-pipe 9 ! /eam-dome4 ,?is valve is op5$ & clos$ by means ( a rod 9 ! eng9e]'s cab4 ,/eph5son's l9k-motion valve-ge> is us$ on mo/ locomotives4 ,! =w>d rod 9 ! diagram is 9 position to act ^u ! valve-rod ?r\gh ! lev] ,l4 ,suppose ! rev]s+-lev] is drawn back to ! dott$ l9e2 !n ! =w>d rod w be rais$ & ! backw>d rod w come into position to act on ! lev] ,l4 ,if ?is is done :ile ! locomotive is at re/ ! valve is mov$ ?r\gh "o-half a complete /roke4 ,9 ! diagram ! /eam ent]s ! cyl9d] on ! "r ( ! pi/on4 ,aft] ?is movem5t ( ! valve ! /eam w\ld ent] on ! left side ( ! pi/on4 ,9 ! pres5t position ! locomotive w\ld move =w>d1 b if ! valve is *ang$ s z to admit /eam to ! left ( ! pi/on :ile ! connect+-rod is 9 ! position %[n !n ! eng9e w move backw>d4 ,?us ! direction c be controll$ by ! eng9e] 9 ! cab4 ,( c\rse1 ?is c be done :ile ! eng9e is 9 motion4 ,! =w>d rod & ! backw>d rod are ea* mov$ by an ecc5tric on ! axle ( ! front driv+-:eel4 ,! two ecc5trics are 9 opposite positions on ! axle4 ,an ecc5tric acts j l a crank1 caus+ ! rod to move =w>d & backw>d z ! axle turns1 & ( c\rse ?is motion is giv5 to ! valve-rod ?r\gh ! lev]4 ,:5 ! l9k is set midway betwe5 ! =w>d & ! backw>d rod ! valve _c move4 ,:5 ! l9k is rais$ or l[]$ "p way ! valve makes a %ort /roke1 & less /eam is admitt$ to ! cyl9d] ?an ) a full /roke4 ,9 />t+ ! locomotive ! valve is set to make a full /roke4 ,:5 ! tra9 is "u headway ! valve is set = a %ort /roke to economize /eam4 ,! valve-ge> & ! ?rottle-valve toge!r take ! place ( ! gov]nor 9 ! /ation>y eng9e1 b :ile ! gov]nor acts automatically ^! are controll$ by ! eng9e]4 ,9 reality a locomotive is two eng9es1 "o on ei!r side1 connect$ to ! same driv+-:eels4 ,b ! two pi/on-rods are connect$ to ! driv+-:eels at po9ts :i* are at "r angles ) ea* o!r1 s t :5 ! crank on "o side is at ! end ( a /roke--! dead c5tre--t on ! o!r side is on ! qu>t]1 ei!r above or bel[ ! axle1 ready = apply+ ! greate/ turn+ =ce4 ,! expansion-eng9e 0 design$ to use m ( ! p[] ( ! /eam ?an c be done 9 ! s+le-cyl9d] eng9e4 ,9 ! d\ble expansion-eng9e ! /eam exp&s f "o cyl9d] into ano!r4 ,! second cyl9d] mu/ be l>g] 9 diamet] ?an ! fir/4 ,9 ! triple expansion-eng9e ! /eam exp&s f ! second cyl9d] into a ?ird1 /ill l>g]4 ,! second & ?ird cyl9d]s use a l>ge "p ( ! p[] t w\ld be wa/$ ) only "o cyl9d]4 ,! ,turb9e ,"o ( ! great inv5tions relat+ to /eam-p[] is ! /eam-turb9e4 ,! wat]-turb9e is equally useful 9 relation to wat]-p[]4 ,! wat]-turb9e & ! /eam-turb9e "w 9 v mu* ! same way1 ! diff]5ce be+ due to ! fact t /eam exp&s z x drives ! eng9e1 :ile wat] drives x by its weight 9 fall+1 or by its motion z x ru%es 9 a swift /ream or jet aga9/ ! blades ( ! turb9e4 ,! fir/ /eam-eng9e1 t ( ,h]o 9 ! "t ( ,ar*im$es1 0 a =m ( turb9e 7,fig4 #hb74 ,x 0 driv5 by ! reaction ( ! /eam z x escap$ into ! air4 ,! common lawn-spr9kl]1 t :irls z ! wat] ru%es ?r\gh x1 is a wat]-turb9e t works 9 ! same way4 ,b>k]'s ,mill is ! "n appli$ to a wat]-turb9e t works l ! lawn-spr9kl]4 ,z ! wat] ru%es out ( ! op5+ x pu%es aga9/ ! air4 ,x _c pu% aga9/ ! air )\t pu%+ back at ! same "t4 ,nev] yet has any p]son or object 9 nature be5 able to pu% 9 "o direction only4 ,x _c be done4 ,if y pu% a c>t =w>d y pu% backw>d aga9/ ! gr\nd at ! same "t4 ,if !re 7 no?+ = y to pu% back aga9/ y\r =w>d pu% w\ld n move ! c>t a hair's-bread?4 ,if y d\bt ?is1 try to pu% a c>t :5 y are /&+ on ice s slipp]y t y _c get a foo?old4 ,x is ! backw>d pu% ( ! wat] 9 ! lawn-spr9kl] & ! backw>d pu% ( ! /eam 9 ,h]o's eng9e t cause ! ma*9e to turn4 ,illu/ration3 ,,fig4 #hb--;,,h]o',s ,,eng9e ,! turb9es 9 common use = bo? wat] & /eam p[] h curv$ blades4 ,! reason = curv+ ! blades c be/ be se5 by ref]r+ to an e>ly =m ( wat]-:eel4 ,! be/ wat]-turb9e is only an improv$ =m ( wat]-:eel4 ,! fir/ wat]-:eels _h flat blades1 & ^! answ]$ v well s long z only a l[ p[] 0 ne$$ & x 0 n necess>y to save ! p[] ( ! wat]4 ,x 0 f\nd1 h[ev]1 t !re 0 a great wa/e ( p[] 9 ! :eel ) flat blades4 ,"o inv5tor propos$ to improve ! :eel by curv+ ! blades 9 su* a way t ! wat] w\ld glide up ! curve & !n drop directly d[nw>d 7,fig4 #hc74 ,! wat] !n gives up practically all ( its p[] to ! :eel & falls f ! :eel4 ,x w\ld h no p[] to move a second :eel4 ,9 ?is way he us$ practically all ! p[] ( ! wat]4 ,to save ! p[] ( ! wat] by mak+ all ( ! wat] /rike ! :eel at high spe$ ! *annel 0 made n>r[ j above ! :eel1 =m+ a mill-race4 ,?is applies to ! und]%ot :eel4 ,9 ! ov]%ot :eel 7,fig4 #hd7 ! p[] dep5ds on ! weight ( ! wat] & on its height4 ,! wat] runs into buckets atta*$ to ! :eel1 &1 z x falls 9 ^! buckets1 turns ! :eel4 ,! und]%ot :eel & ! mill-race repres5t a common =m ( turb9e1 t =m 9 :i* ! /eam or ! wat] is =c$ 9 a jet aga9/ a set ( curv$ blades4 ,fig4 #he %[s a /eam-turb9e run by a jet ( /eam4 ,9 ! wat]-turb9e !re are two sets ( blades4 ,"o set rotates1 ! o!r rema9s fix$4 ,! use ( ! fix$ blades is to turn ! wat] & drive x 9 ! "r direction aga9/ ! mov+ blades4 ,9 "s =ms ( turb9e !re are m ?an two sets ( blades4 ,! /eam1 z x passes ?r\gh1 gives up "s ( its p[] to ea* set ( blades until1 aft] pass+ ! la/ set1 x has giv5 up ne>ly all its p[]4 ,! action ( ! /eam 9 ?is turb9e is some:at l t 9 ! expansion-eng9e1 9 :i* ! /eam gives up a portion ( its p[] 9 ea* cyl9d]4 ,fig4 #hf is f a photograph ( a mod]n /eam-turb9e1 & ,fig4 #hg is a draw+ ( ! same turb9e %[+ ! c\rse ( ! /eam4 ,fig4 #hh is a turb9e t runs a l>ge dynamo4 ,illu/ration3 ,,fig4 #hc--;,,an ,,und]%ot ,,wat]-,,:eel ,,) ,,curv$ ,,blades ,illu/ration3 ,,fig4 #hd--;,,an ,,ov]%ot ,,wat]-,,:eel ,illu/ration3 ,,fig4 #he--;,,de ,,laval ,,/eam-,,turb9e ,driv5 by a jet ( /eam /rik+ ! blades4 ,illu/ration3 ,,fig4 #hf--;,a ,,mod]n ,,/eam-,,turb9e ,,) ,,top ,,cas+ ,,rais$ ,,%[+ ,,blades ,illu/ration3 ,,fig4 #hg--;,,diagram ,,( ,,turb9e ,,%[n ,,9 ,,fig4 #hf ,! arr[s %[ ! c\rse ( ! /eam4 ,illu/ration3 ,,fig4 #hh--;,a ,,/eam-,,turb9e ,,t ,,runs ,a ,,dynamo ,,g5]at+ #ad1jjj ,,electrical ,,horse-,,p[] ,! /eam ent]s ?r\gh ! l>ge pipe at ! left4 ,9 #ahig1 z ! battle-%ips ( ! ,briti% fleet 7 assembl$ to celebrate ! ,diamond jubilee ( ,que5 ,victoria1 a little vessel a hundr$ feet long d>t$ 9 & out among ! giant %ips1 defi$ ! patrol-boats ^: duty x 0 to keep out intrud]s1 & rac$ d[n ! l9es ( battle-%ips at ! !n unhe>d-( spe$ ( ?irty-five knots an h\r4 ,x 0 ! ,turb9ia1 fitt$ ) ! ,p>sons turb9e4 ,?is ev5t m>k$ ! beg9n+ ( ! mod]n turb9e4 ,x also m>k$ ! beg9n+ ( a revolution 9 /eam propulsion4 ,! ,p>sons turb9e does n use ! jet me?od1 b ! /eam ent]s ne> ! c5tre ( ! :eel & fl[s t[>d ! rim1 pass+ ov] a numb] ( r[s ( curv$ blades4 ,! ,p>sons turb9e is us$ on ! fa/e/ ocean l9]s4 ,! ,lusitania1 "o ( ! fa/e/ /eam%ips 9 ! fir/ decade ( ! tw5tie? c5tury1 has two sets ( high & l[ pressure turb9es ) a total ( #fh1jjj horse-p[]4 ,! w9dmill is a =m ( turb9e driv5 by ! air4 ,z ! air ru%es aga9/ ! blades ( ! w9dmill1 x =ces !m to turn4 ,if ! w9dmill 7 turn$ by "s me*anical p[]1 x w\ld drive ! air back1 & we %\ld h a bl[]4 ,?is is :at we h 9 ! electric fan1 a small w9dmill driv5 by an electric motor s t x drives ! air in/ead ( be+ driv5 by x4 ,! blades ( ! w9dmill & ! electric fan are %ap$ v mu* l ! screw propell]4 ,! screw propell]1 driv5 by an eng9e1 w\ld drive ! wat] back if ! %ip 7 firmly an*or$1 j z ! fan drives ! air4 ,b x _c drive ! wat] back )\t pu%+ =w>d on ! %ip at ! same "t1 & ?is =w>d pu% propels ! %ip4 ,x is difficult to atta9 :at is n[ reg>d$ z high spe$ ) a s+le screw4 ,) eng9es 9 pairs & two l9es ( %aft+ high] p[] c be us$4 ,! be/ /eam]s1 !re=e1 are fitt$ ) ! tw9-screw propell]4 ,"s l>ge /eam]s h ?ree & "s f\r screws4 ,! screw propell]s ( turb9e /eam%ips are made ( small diamet]1 t !y may rotate at high spe$ )\t undue wa/e ( p[]4 ,by ! use ( turb9e eng9es & tw9-screw propell]s1 ! weight ( ! ma*9]y has be5 greatly r$uc$4 ,! old paddle-:eels1 ) l[-pressure eng9es1 develop$ only ab\t two horse-p[] = ea* ton ( ma*9]y4 ,! turb9e1 ) ! tw9-screw propell]1 develops f six to sev5 horse-p[] = e ton ( ma*9]y4 ,! mod]n /eam]1 ) all its ma*9]y & coal = an ,atlantic voyage1 weighs no m ?an ! eng9es ( ! old paddle-:eel type & coal w\ld weigh = ! same horse-p[]4 ,! /eam-turb9e & ! tw9-screw propell] h made rapid ocean travel possible4 ,*apt] ,,vi ,,! ,,tw5tie?-,,c5tury ,,outlook ,we h se5 t ! latt] half ( ! n9ete5? c5tury 0 a "t ( inv5tion4 ,x 0 a "t :5 ! great discov]ies ( _m c5turies bore fruit 9 great inv5tions4 ,x 0 ?\ght by "s sci5ti/s t all ! great discov]ies _h be5 made1 & t all t rema9$ 0 c>eful "w 9 apply+ ! great pr9ciples t _h be5 discov]$4 ,s f> 0 ?is f be+ true t 9 ! la/ t5 ye>s ( ! n9ete5? c5tury discov]ies 7 made m />tl+1 if possible1 ?an any t _h prec$$4 ,! n9ete5? c5tury n only br\ght =? _m great inv5tions1 b h&$ d[n to ! tw5tie? c5tury a s]ies ( discov]ies t po9t ! way to /ill great] inv5tions4 ,air-,%ips ,= c5turies m5 sail$ ov] ! wat] at ! m]cy ( ! w9d4 ,! sail+ vessel is helpless 9 a /orm4 ,e>ly 9 ! n9ete5? c5tury !y le>n$ to use ! p[] ( /eam = ocean travel1 & ! w9d lo/ its t]rors4 ,late 9 ! eighte5? c5tury m5 le>n$ to sail ?r\gh ! air 9 balloons ev5 m at ! m]cy ( ! w9d ?an ! sail+ vessels on ! ocean4 ,m ?an a hundr$ ye>s lat] !y le>n$ to propel air-%ips 9 ! tee? ( ! w9d4 ,! n9ete5? c5tury saw ! ma/]y ( ! wat]4 ,! tw5tie? is witness+ ! ma/]y ( ! air4 ,! fir/ balloon asc5sion 0 made 9 #aghc1 two m5 be+ c>ri$ ov] ,p>is by :at ,b5jam9 ,frankl9 call$ a bag ( smoke4 ,! balloon 0 a bag ( oil$ silk op5 at ! bottom4 ,9 ! middle ( ! op5+ 0 a grate 9 :i* bundles ( fagots & %eaves ( /raw 7 burn$4 ,! heat$ air fill$ ! balloon1 & z ! heat$ air 0 light] ?an ! air ar\nd x ! balloon c\ld rise & c>ry a load4 ,b5ea? ! grate 0 a wick] c> = ! m54 ,!y 7 suppli$ ) /raw & fagots ) :i* to fe$ ! fire4 ,:5 !y want$ to rise high] !y add$ fuel to heat ! air 9 ! balloon4 ,:5 !y wi%$ to desc5d !y all[$ ! fire to die out1 s t ! air 9 ! balloon w\ld cool4 ,!y c\ld n guide ! balloon1 b drift$ ) ! w9d4 ,t great philosoph] ,b5jam9 ,frankl91 :o saw ! asc5sion1 said t ! "t might come :5 ! balloon c\ld be made to move 9 a calm & guid$ 9 a w9d4 ,9 ! second asc5sion bags ( s& 7 tak5 z balla/1 & ! c> 0 susp5d$ f a net :i* enclos$ ! balloon4 ,9 ?is second asc5sion hydrog5 gas 0 us$ 9 place ( heat$ air4 ,! greate/ height ev] rea*$ by a human be+ is ab\t sev5 miles4 ,?is height 0 fir/ rea*$ 9 #ahfb by two ballooni/s :o ne>ly lo/ _! lives 9 ! adv5ture4 ,at a height ( ne>ly six miles "o ( ! m5 became unconsci\s4 ,! o!r tri$ to pull ! valve-cord to all[ ! gas to escape1 b f\nd t ! cord 0 out ( 8 rea*4 ,8 h&s 7 froz51 b he climb$ out ( ! c> into ! nett+ ( ! balloon1 secur$ ! cord 9 8 tee?1 return$ to ! c>1 & ?rew ! weight ( 8 body on ! cord4 ,?is op5$ ! valve & ! balloon desc5d$4 ,^? :o g to great heights n[ provide !mselves ) tanks ( compress$ oxyg54 ,!n :5 ! air becomes s ?9 & r>e t brea?+ is difficult !y c brea! f ! oxyg5 tanks4 ,a captive balloon 9 w> s]ves z an obs]vation t[] f :i* to obs]ve ! enemy4 ,x is connect$ to ! gr\nd by a cable4 ,?is cable is w\nd on a drum c>ri$ by ! balloon wagon4 ,! balloon c be l[]$ or rais$ by w9d+ or unw9d+ ! cable4 ,! gas-bag is sometimes made ( oil$ silk1 sometimes ( two lay]s ( cotton clo? ) vulcaniz$ rubb] betwe54 ,! cotton clo? gives ! /r5g? ne$$1 & ! rubb] makes ! bag gas-tight4 ,! mo/ conv5i5t gas = fill+ balloons is heat$ air1 b ! air cools rapidly & loses its lift+ p[]4 ,coal-gas furni%$ by city gas-plants is sometimes us$4 ,?is gas w lift ab\t ?irty-five p\nds = e ?\s& cubic feet4 ,a balloon hold+ ?irty-five ?\s& cubic feet ( coal gas w easily lift ! c> & ?ree p]sons4 ,! lighte/ gas is hydrog54 ,?is gas w lift ab\t sev5ty p\nds = e ?\s& cubic feet4 ,hydrog5 is made by ! action ( sulphuric acid & wat] on iron4 ,if a bit ( iron is ?r[n into a mixture ( sulphuric acid & wat] bubbles ( hydrog5 gas w rise ?r\gh ! liquid4 ,?is gas w burn if a light$ mat* is br\ght ne>4 ,a balloon )\t propell+ or /e]+ app>atus is n an air-%ip4 ,x may be rais$ by ?r[+ out balla/ or l[]$ by lett+ out gas1 b fur!r ?an ?is ! a]onaut has no control ov] its movem5ts4 ,! balloon moves ) ! w9d4 ,no breeze is felt1 = balloon & air move toge!r4 ,to ! a]onaut ! balloon seems to be 9 a dead calm4 ,x is only :5 he cat*es sight ( h\ses & trees & riv]s d>t+ pa/ bel[ t he realizes t ! balloon is mov+4 ,if a balloon has a propell+ app>atus x may move aga9/ ! w9d1 or x may outspe$ ! w9d4 ,a balloon ) propell+ & /e]+ app>atus is call$ a dirigible balloon1 :i* means a balloon t c be guid$4 ,figs4 #hi & #ij are f photographs ( a dirigible us$ 9 ! ,briti% army4 ,su* a balloon is usually long & po9t$ l a sp9dle or a cig>4 ,x is built to cut ! air1 j z a r[boat built = spe$ is long & po9t$ s t x may cut ! wat]4 ,! propell] acts l an electric fan4 ,an electric fan drives ! air be=e x1 b ! air pu%es back on ! fan j z mu* z ! fan pu%es =w>d on ! air1 & if ! fan 7 susp5d$ by a long cord x w\ld move backw>d4 ,s ! l>ge fan or screw propell] on an air-%ip drives ! air backw>d1 & ! air reacts & drives ! %ip =w>d4 ,9 ! same way ! screw-propell] ( an ocean l9] drives ! vessel =w>d by ! reaction ( ! wat]4 ,illu/ration3 ,,fig4 #hi--;,,briti% ,,army ,,air-,,%ip ,,nulli ,,secundus ,,ready ,,= ,,flight ,illu/ration3 ,,fig4 #ij--;,,basket1 ,,motor1 ,,& ,,propell] ,,( ,,! ,,briti% ,,army ,,air-,,%ip ,,nulli ,,secundus ,a balloon rises = ! same reason t wood floats on wat]4 ,! wood is light] ?an wat]1 & ! wat] holds x up4 ,! balloon is light] ?an air & ! air pu%es x up4 ,! upw>d pu% ( ! air is j equal to ! weight ( ! air t w\ld fill ! same space ! balloon fills4 ,! balloon c support a load t makes ! :ole weight ( ! balloon & its load toge!r equal to ! weight ( ! air t w\ld fill ! same space4 ,= ! balloon to rise ! load mu/ be some:at light] ?an ?is4 ,a balloon may be made light] ?an air by fill+ x ) heat$ air or coal-gas4 ,hydrog51 h[ev]1 is us$ 9 ! bett] balloons & 9 air-%ips ( ! light] ?an air type4 ,! air-%ip mu/1 ( c\rse1 use a v light motor4 ,a /eam-eng9e _c be made light en\gh4 ,nei!r c an electric motor1 if we add ! weight ( ! /orage batt]y t w\ld be requir$4 ,air-%ips h be5 propell$ by bo? /eam-eng9es & electric motors1 b ) l[ spe$ because ( ! weight ( ! eng9e or motor4 ,! only successful motor = ?is purpose is ! gasol5e motor1 :i* is a =m ( gas-eng9e us+ gas =m$ by ! evaporation ( gasol5e4 ,! fir/ air-%ip t c\ld be controll$ & br\ght back to ! />t+-po9t 0 made 9 ,france1 9 #ahhe1 by ,capta9 ,r5>d1 ( ! ,fr5* army4 ,x 0 a cig>-%ap$ balloon1 ) a screw propell] run by an electric motor ( eight horse-p[]4 ,! %ip atta9$ a spe$ ( ?irte5 miles an h\r4 ,a m successful air-%ip 0 t built by ,santos ,dumont4 ,) ?is %ip1 9 #aija1 he won a prize ( #bj1jjj1 :i* _h be5 (f]$ to ! build] ( ! fir/ air-%ip t w\ld sail r\nd ! ,eiffel ,t[] 9 ,p>is f ! ,a]o/atic ,p>k ( ,vaugir>d1 a di/ance ( ab\t ?ree miles1 & return 9 half an h\r4 ,! balloon "p ( ?is air-%ip 0 #aab-a_/b feet long & #ai-a_/b feet 9 diamet]1 hold+ ab\t #fdjj cubic feet ( gas4 ,! c> 0 built ( p9e beams no l>g] 9 section ?an two f+]s & weigh+ only #aaj p\nds4 ,?is c> c\ld be tak5 ap>t & put 9 a trunk4 ,a gasol5e automobile motor 0 us$1 & ?us x is se5 t ! automobile aid$ 9 solv+ ! problem ( sail+ ?r\gh ! air4 ,x 0 ! automobile t l$ to ! con/ruction ( light & p[]ful gasol5e motors4 ,! c> & motor 7 susp5d$ f ! balloon by means ( piano wires1 :i* at a %ort di/ance 7 invisible1 s t ! man 9 ! c> appe>$ 9 "s my/]i\s way to foll[ ! balloon4 ,! %ip 0 turn$ to ! left or "r by means ( a rudd]4 ,x 0 made to asc5d or desc5d by %ift+ ! weight ( a heavy rope t hung f ! c>1 ?us incl9+ ! %ip upw>d or d[nw>d4 ,c\nt ,zeppel91 ( ,g]many1 con/ruct$ a mu* l>g] dirigible balloon ?an t ( ,santos ,dumont4 ,! balloon ( ! fir/ ,zeppel9 air-%ip 0 #cij feet 9 l5g?1 ) a diamet] ( ab\t #ci feet4 ,x 0 divid$ into sev5te5 sections1 ea* section be+ a balloon 9 itself4 ,^! sections s]ve ! same purpose z ! wat]-tight comp>tm5ts ( a battle-%ip4 ,an accid5t to "o section w\ld n mean ! de/ruction ( ! entire %ip4 ,)9 ! balloon is a framework ( alum9um rods ext5d+ f "o end to ! o!r & held 9 place by alum9um r+s tw5ty-f\r feet ap>t4 ,! balloon conta9s ab\t #ajh1jjj cubic feet ( gas1 & x co/s ab\t #bejj to fill x4 ,"o fill+ ( gas w la/ ab\t ?ree weeks4 ,!re are two c>s1 ea* ab\t t5 feet long1 five feet wide1 & ?ree feet deep4 ,! c>s are connect$ by a n>r[ passageway made ( alum9um wires & plates1 mak+ a walk+ di/ance ( #cbf feet--long] ?an ! decks ( _m ocean /eam]s4 ,a slid+ weight ( #cjj kilograms 7ab\t #fjj p\nds7 s]ves ! same purpose z ! guide-ropes 9 ! ,santos ,dumont air-%ip4 ,by mov+ ?is weight =w>d or backw>d ! %ip is rais$ or l[]$ at ! b[ or /]n1 & ?us caus$ to glide up or d[n4 ,an*or-ropes are c>ri$ = use 9 l&+4 ,! %ip is propell$ by f\r screws1 & guid$ by a numb] ( rudd]s plac$ "s 9 front & "s 9 ! re>4 ,! fir/ ,zeppel9 air-%ip c>ri$ f\r pass5g]s4 ,! "w ( ,dumont & ,zeppel9 has l$ ! great p[]s to manufacture dirigible balloons = use 9 "t ( w>4 ,fig4 #ia %[s "o ( ! ,zeppel9 air-%ips sail+ ov] a lake4 ,illu/ration3 ,,fig4 #ia--;,a ,,zeppel9 ,,air-,,%ip ,a l>g] air-%ip1 ! ,deuts*l&1 built lat] by ,c\nt ,zeppel91 0 ! fir/ air-%ip to be us$ = regul> pass5g] s]vice4 ,! ,deuts*l& is %[n 9 ,fig4 #ib4 ,! ,deuts*l& c>ri$ ! crew & tw5ty pass5g]s4 ,x op]at$ = a "t z a regul> pass5g] air-%ip betwe5 ,fri$ri*%af5 & ,dsseldorf1 a di/ance ( ?ree hundr$ miles4 ,! ,deuts*l& 0 wreck$ 9 a /orm on ,june #bh1 #aiaj1 b x 0 successfully op]at$ long en\gh to give ,g]many ! honor ( e/abli%+ ! fir/ air-%ip l9e = regul> pass5g] s]vice4 ,?is is an honor p]haps equally z great z t ( e/abli%+ ! fir/ comm]cial electric railway1 :i* also belongs to ,g]many4 ,an ,am]ican army air-%ip is %[n 9 ,fig4 #ic4 ,illu/ration3 ,,fig4 #ib--;,,c\nt ,,zeppel9',s ,,deuts*l&1 ,,! ,,fir/ ,,air-,,%ip ,,9 ,,regul> ,,pass5g] ,,s]vice ,illu/ration3 ,copyright by ,pictorial ,news ,co4 ,,fig4 #ic--,,! ,,baldw9 ,,air-,,%ip ,,us$ ,,9 ,,! ,,unit$ ,,/ates ,,army ,! ,a]oplane ,! a]oplane is a lat] developm5t ?an ! dirigible balloon4 ,! a]oplane is heavi] ?an air4 ,s is a bird & s is a kite4 ,:at supports a kite or a bird z x so>s8 ,e boy kn[s t ! /r+s ( a kite mu/ be atta*$ s t ! kite is incl9$ & cat*es ! w9d und]nea?4 ,!n ! w9d lifts ! kite4 ,9 /ill air ! kite w n fly unless ! boy :o holds ! /r+ runs v fa/ & s causes an artificial breeze to bl[ aga9/ ! kite4 ,9 mu* ! same way a hov]+ bird is held al(t by ! w9d4 ,9 a dead calm ! bird mu/ flap its w+s to keep afloat4 ,if ! kite /r+ is cut ! kite tips ov] & drops to ! e>? because x has lo/ its balance4 ,! lift+ p[] ( ! w9d is well %[n 9 ! man-lift+ kites :i* are us$ 9 ! ,briti% army s]vice4 ,9 a high w9d a l>ge kite is us$ 9 place ( a captive balloon4 ,x is a box-kite made ( bamboo & c>ries a pass5g] 9 a c>1 ! c> runn+ on ! cable :i* atta*es ! kite to ! gr\nd4 ,n[ suppose a kite ) a motor & propell] 9 place ( a /r+ & a boy to run ) x1 & t ! kite is able to balance itself1 !n x w sail aga9/ a w9d ( its own mak+ & y h a fly+-ma*9e heavi] ?an air4 ,! fir/ a]oplane t w\ld fly "u p]fect control ( ! op]ator 0 built by ! ,wright bro!rs at ,dayton1 ,ohio4 ,:5 !y 7 boys1 ,bi%op ,wright gave 8 two sons1 ,orville & ,wilbur1 a toy fly]4 ,f t "t on ! ?\ght ( fly+ ?r\gh ! air 0 9 _! m9ds4 ,a few ye>s lat] ! dea? ( ,lili5?al1 :o 0 kill$ by a fall ) 8 glid] 9 ,g]many1 /irr$ !m1 & !y took up ! problem 9 e>ne/4 ,!y read all ! writ+s ( ,lili5?al & became acqua9t$ ) ,mr4 ,octave ,*anute1 an eng9e] ( ,*icago :o _h made a successful glid]4 ,!y soon built a glid] ( _! own1 & exp]im5t$ ) x ea* summ] on ! huge s&-dunes ( ! ,nor? ,c>ol9a coa/4 ,a glid] is an a]oplane )\t a propell]4 ,) x "o c ca/ (f into ! air f a great height & sail sl[ly to ! gr\nd4 ,be=e attempt+ to use a motor & propell]1 ! ,wrights le>n$ to control ! glid] p]fectly4 ,!y _h to le>n h[ to prev5t its be+ tipp$ ov] by ! w9d1 & h[ to /e] x 9 any direction4 ,?is took ye>s ( pati5t "w4 ,b ! problem 0 conqu]$ at la/1 & !y atta*$ a motor & propell] to ! glid]1 & _h an air-%ip "u p]fect control & ) ! spe$ ( an express-tra94 ,_! fly] ( #aije1 :i* made a flight ( tw5ty-f\r miles at a spe$ ( m ?an ?irty-eight miles an h\r1 c>ri$ a tw5ty-five-horse-p[] gasol5e motor1 & weigh$1 ) its load1 #ibe p\nds4 ,figs4 #id & #ie %[ ! ,wright air-%ip 9 flight4 ,fig4 #ig %[s ! me*anism4 ,illu/ration3 ,,fig4 #id--;,,9 ,,full ,,flight ,illu/ration3 ,copyright1 #aijh1 by ,pictorial ,news ,co4 ,,fig4 #ie--,,wright ,,air-,,%ip ,,9 ,,flight ,re> view1 %[+ propell]s4 ,illu/ration3 ,,fig4 #ig--,,! ,,seat ,,& ,,motor ,,( ,,! ,,wright ,,a]oplane ,photo by ,pictorial ,news ,co4 ,h[ ! ,wright ,a]oplane ,is ,kept ,afloat ,! ,wright a]oplane is balanc$ by a w>p+ or twi/+ ( ! planes #a & #b1 :i* =m ! support+ surfaces 7,fig4 #if74 ,if left to itself ! ma*9e w\ld tip ov] l a kite :5 ! /r+ is cut & drop edgewise to ! gr\nd4 ,suppose ! side ,r />ts to fall4 ,! corn]s a & e are rais$ by ! op]ator :ile b & f are l[]$1 ?us twi/+ ! planes1 z %[n 9 ! dott$ l9es ( ! figure4 ,! side ,r !n cat*es m w9d ?an ! side ,l4 ,! w9d ex]ts a great] lift+ =ce on ,r ?an on ,l1 & ! balance is re/or$4 ,! twi/ is !n tak5 out ( ! ma*9e by ! op]ator4 ,a %ip :5 sail+ on an ev5 keel pres5ts true unw>p$ planes to ! w9d4 ,illu/ration3 ,,fig4 #if--;,,h[ ,,! ,,wright ,,air-,,%ip ,,is ,,kept ,,afloat ,?is picture repres5ts a glid]4 ,! motor-driv5 a]oplane is balanc$ by ! w>p+ ( ! planes 9 ! same way z ! glid]4 ,! twi/+ is br\ght ab\t by a pull on ! rope #c1 :i* is atta*$ at d & c1 & passes ?r\gh pulleys at g & h4 ,:5 ! rope is pull$ t[>d ! left ! "r end is tight5$ & slack is paid out at ! left end4 ,?is pulls d[n ! corn] d1 & raises e4 ,! corn] a is rais$ by ! po/ :i* connects a & e4 ,! rope #d1 pass+ f a to b ?r\gh pulleys at m & n1 is ?us drawn t[>d a & pulls d[n ! corn] b4 ,?us a is rais$ & b is l[]$4 ,at ! same "t rope #d turns ! re> rudd] to ! left1 z %[n by ! dott$ l9es1 ?us =c+ ! side ,r aga9/ ! w9d4 ,( c\rse1 if ! left side ( ! ma*9e />ts to fall1 ! rope #c is pull$ t[>d ! "r1 & all ! movem5ts take place 9 ! opposite direction4 ,! ropes are connect$ to a lev]1 by :i* ! op]ator controls ! w>p+ ( ! planes4 ,^! movem5ts are possible because ! jo9ts are all univ]sal1 p]mitt+ movem5t 9 any direction4 ,9 :atev] position ! planes may be set1 !y are held p]fectly rigid by ! two ropes1 toge!r ) o!rs n %[n 9 ! figure4 ,! ma*9e is guid$ up or d[n by ! front horizontal rudd]4 ,:5 ! a]oplane sw+s r\nd a curve ! out] w+ is rais$ because x moves fa/] ?an ! inn] w+1 & !re=e has great] lift+ =ce4 ,?us ! a]oplane banks its own curves4 ,! ,wright fly+-ma*9e is call$ a biplane because x has two pr9cipal planes1 "o above ! o!r4 ,a numb] ( successful fly+-ma*9es h be5 built ) only "o plane1 & ^! are call$ monoplanes4 ,a monoplane t e>ly became fam\s is t ( ,blriot 7,fig4 #ih74 ,! ,blriot monoplane 0 ! fir/ fly+-ma*9e to cross ! ,engli% ,*annel4 ,?is ma*9e is controll$ by a s+le lev] m\nt$ ) a ball-&-socket c\pl+1 s t x c move 9 any direction4 ,:5 on ! gr\nd x is support$ by ?ree :eels l bicycle :eels1 s t x does n require a track = />t+1 b c />t any:]e f level gr\nd4 ,! ,wright & ! ,blriot repres5t ! two lead+ types ( e>ly successful fly+-ma*9es4 ,illu/ration3 ,copyright by ,m4 ,braug]1 ,p>is ,,fig4 #ih--,,! ,,bl,,riot ,,monoplane ,subm>9es ,successful navigation b5ea? ! surface ( ! wat]1 ?\gh n c>ri$ to ! ext5t imag9$ by ,jules ,v]ne1 0 a reality at ! beg9n+ ( ! tw5tie? c5tury4 ,in/ead ( tw5ty ?\s& leagues "u ! sea1 less ?an a hundr$ leagues _h be5 accompli%$1 b no "o c =etell :at ! future may h 9 /ore4 ,! pr9cipal use ( ! subm>9e is 9 w>4 ,x is a div+ torp$o-boat1 & acts "u cov] ( wat]1 z ! light artill]y on l& is secur$ beh9d intr5*m5ts4 ,! weapon us$ by ! subm>9e is ! torp$o4 ,! torp$o is itself a small subm>9e able to propel itself1 & if />t$ 9 ! wat] t[>d a c]ta9 object1 to g "u wat] /raight to ! m>k4 ,x c>ries a heavy *>ge ei!r ( guncotton or dynamite1 :i* explodes :5 ! torp$o /rikes a solid object1 su* z a battle-%ip4 ,! fir/ torp$o 0 int5d$ to be /e]$ f ! %ore by means ( long till]-ropes1 & to be propell$ by a /eam-eng9e or by clockwork4 ,! ,:itehead fi% torp$o1 inv5t$ 9 #ahff1 is self-/e]+4 ,at ! head ( ! torp$o is a po9t$ /eel fir+-p94 ,:5 ! torp$o /rikes a %ip or any rigid object ?is /eel p9 is driv5 aga9/ a detonator cap :i* is 9 ! c5tre ( ! *>ge ( dynamite4 ,! bl[ causes ! cap to explode1 & ! explosion ( ! cap explodes ! dynamite4 ,! torp$o is s arrang$ t x _c explode until x is ab\t ?irty y>ds away f ! %ip f :i* x is fir$4 ,! /eel p9 _c /rike ! cap until a small coll> has be5 revolv$ (f by a propell] fan1 & ?is requires a di/ance ( ab\t ?irty y>ds4 ,! screw propell] is driv5 by compress$ air4 ,a valve :i* is work$ by ! pressure ( ! wat] keeps ! torp$o at any dep? = :i* ! valve is set4 ,! torp$o conta9s _m +5i\s devices = br++ x quickly to ! requir$ dep? & keep+ x /raight 9 its c\rse4 ,"o ( ^! devices is ! gyroscope1 :i* w be describ$ "u ! head ( sp9n+ tops4 ,:itehead torp$oes are capable ( runn+ at a spe$ ( ov] ?irty-sev5 miles an h\r = a range ( two ?\s& y>ds & hitt+ ! m>k aim$ at almo/ z accurately z a gun4 ,! subm>9e boat c>ries a numb] ( torp$oes1 & has "o torp$o-tube ne> ! =w>d end f :i* to fire ! torp$oes4 ,x w\ld be v difficult = "o subm>9e to fight ano!r subm>9e1 = ! subm>9e :5 completely subm]g$ is bl9d4 ,x c\ld n see 9 ! wat] to f9d its enemy4 ,! torp$o-boat-de/roy] is able to de/roy a subm>9e by means ( torp$oes1 %ells full ( high explosives1 or quick-fir+ guns4 ,advantage mu/ be tak5 ( ! mom5t :5 ! subm>9e comes to ! surface to get a view ( h] enemy4 ,"o ( ! great enemies ( ! subm>9e w probably be ! air-%ip1 = :ile ! subm>9e :5 "u wat] _c be se5 f a %ip on ! surface1 x c1 "u favorable conditions1 be se5 f a c]ta9 height 9 ! air4 ,mo/ subm>9es use a gasol5e motor = surface travel1 & an electric motor run by a /orage batt]y = navigation bel[ ! surface4 ,! be/ subm>9es c travel at ! surface l an ord9>y boat1 or awa%--t is1 j bel[ ! surface--) only ! conn+ t[] project+ above ! wat]1 or !y c travel completely subm]g$4 ,! ris+ & s9k+ ( ! subm>9e dep5d on ! pr9ciple ( ,ar*im$es4 ,! upw>d pu% ( ! wat] is j equal to ! weight ( ! wat] displac$4 ,if ! wat] displac$ weighs m ?an ! boat1 !n ! upw>d pu% ( ! wat] is great] ?an ! weight ( ! boat & ! boat rises4 ,h[ev]1 ! boat c be made to dive :5 its weight is j a little less ?an ! weight ( ! wat] displac$4 ,?is is done by means ( horizontal rudd]s :i* may be incl9$ s z to cause ! boat to glide d[nw>d z its propell] drives x =w>d4 ,! magnetic compass is n reliable 9 a subm>9e ) a hull made ( /eel4 ,! electric motor us$ = propell+ ! boat "u wat] also int]f]es ) ! action ( ! compass1 because ( its magnetic field4 ,! gyroscope1 :i* we %all describe lat]1 is n affect$ by magnetic action1 & may take ! place ( ! compass4 ,wat] balla/ is us$1 & :5 ! subm>9e wi%es to dive1 wat] is admitt$ into ! tanks until ! boat is ne>ly heavy en\gh to s9k ( its own weight4 ,x is !n guid$ d[nw>d by ! horizontal rudd]4 ,! subm>9e is driv5 by a screw propell]1 & "s subm>9es are l[]$ by means ( a v]tical screw4 ,j z a horizontal screw propels a vessel =w>d1 s a v]tical screw w propel x d[nw>d4 ,:5 ! subm>9e wi%es to rise1 x may d s by ! action ( its rudd]1 or ! wat] may be pump$ out ( its tanks1 :5 ! wat] w raise x rapidly4 ,a subm>9e :i* is kept always a little light] ?an wat] w rise to ! surface 9 case ( accid5t to its ma*9]y4 ,figs4 #ii1 #ajj1 & #aja are f photographs ( ,unit$ ,/ates subm>9es4 ,illu/ration3 ,,fig4 #ii--,,! ,,plung] ,photo by ,pictorial ,news ,co4 ,illu/ration3 ,,fig4 #ajj--,u4 ,s4 ,,subm>9e ,,%>k ,,ready ,,= ,a ,,dive ,photo by ,pictorial ,news ,co4 ,illu/ration3 ,,fig4 #aja--;,,fir/ ,,subm>9e ,,con/ruct$ ,,9 ,,unit$ ,,/ates4 ,,x ,,w5t ,,to ,,! ,,bottom ,,) ,,sev5 ,,m51 ,,:o ,,7 ,,dr[n$ ,photo by ,pictorial ,news ,co4 ,!re is "o k9d ( subm>9e built = peaceful pursuits :i* des]ves m5tion4 ,x is ! ,argonaut1 inv5t$ by ,simon ,lake4 ,?is rem>kable boat crawls along ! bottom ( ! sea1 b n at a v great dep?4 ,x is equipp$ ) div]s' appliances1 & is us$ 9 sav+ wreckage4 ,div]s c g out ?r\gh ! bottom ( ! boat1 walk ab\t on ! sea bottom1 & :5 ?r\gh ) _! "w re-ent] ! boat2 all ! :ile boat & m5 are1 p]haps1 a hundr$ feet bel[ ! surface4 ,! div]s' comp>tm5t1 f :i* ! div]s g out into ! wat]1 is sep>at$ by an air-tight p>tition f ! re/ ( ! boat4 ,compress$ air is =c$ into ?is comp>tm5t until ! pressure ( ! air equals ! pressure ( ! wat] outside4 ,!n ! door 9 ! bottom is op5$1 & ! air keeps ! wat] out4 ,! m5 9 _! div+-suits c !n g out & 9 z !y please4 ,= e boat !re is a dep? beyond :i* x mu/ n g4 ,! p5alty = go+ beyond ?is dep? is a batt]$-9 vessel1 = ! pressure increases ) ! dep?4 ,e "t ! dep? is increas$ ?irty-two feet ! pressure is increas$ fifte5 p\nds on e squ>e in*4 ,beyond a c]ta9 dep? ! vessel _c resi/ ! pressure4 ,subm>9es h be5 made /rong en\gh to )/& ! pressure at a dep? ( five ?\s& feet1 or ne>ly a mile4 ,mo/ subm>9es1 h[ev]1 _c g deep] ?an a hundr$ & fifty feet4 ,air is suppli$ to ! occupants ( ! boat ei!r f res]voirs conta9+ compress$ air or oxyg51 or by means ( *emicals :i* absorb ! c>bon dioxide produc$ 9 brea?+ & re/ore ! ne$$ quantity ( oxyg5 to ! air4 ,:ile ! m5 9 ! boat _c see 9 ! wat]1 !y c see objects on ! surface ( ! wat]1 ev5 :5 _! boat is sev]al feet bel[ ! surface1 by means ( ! p]iscope4 ,?is is an arrangem5t ( l5ses & mirrors 9 a tube b5t 9 two "r angles1 :i* projects a %ort di/ance above ! surface & c be turn$ 9 any direction 7,fig4 #ajb74 ,?us ! boat1 :ile itself ne>ly invisible1 c h a cle> view ( ! battle-%ip :i* x is ab\t to attack4 ,illu/ration3 ,,fig4 #ajb--;,,h[ ,,m5 ,,9 ,a ,,subm>9e ,,see ,,:5 ,,"u ,,! ,,wat] ,"s ,sp9n+ ,tops t ,are ,useful ,e "o kn[s t a top w /& upright only :5 x is sp9n+4 ,mo/ tops :5 sp9n+ w /& v r\gh treatm5t )\t be+ upset4 ,! :ip-top w /& a sev]e la%+4 ,sp9 a top upright & give x a knock4 ,x w g r\nd 9 a circle 9 a slant+ position1 & aft] a "t w "r itself4 ,if ! top is /ruck t[>d ! s\? x w n b[ t[>d ! s\? b t[>d ! ea/ or we/4 ,9 ?r[+ a quoit1 ! quoit mu/ be giv5 a sp9n+ motion or ! ?r[] _c be c]ta9 h[ x w alight4 ,a co9 ?r[n up ) a sp9n+ motion w n turn ov]4 ,! quoit & ! co9 are l ! top4 ,!y w n turn ov] easily :5 sp9n+4 ,= ! same reason a rifle bullet is set sp9n+ by ! spiral grooves 9 ! bore ( ! gun1 & x goes /raight to its m>k4 ,) a smoo?-bore gun t does n set ! bullet sp9n+ ! gunn] _c be sure ( 8 aim4 ,x took a long "t to discov] t ! sp9n+ top is a useful ma*9e4 ,x is useful because ( its /eady motion1 because x is difficult to turn ov]4 ,x 0 discov]$ by ,newton long ago t e mov+ object tries to keep on 9 ! direction 9 :i* x is mov+4 ,a mov+ object always requires "s =ce to *ange its direction4 ,! sp9n+ top is a beautiful illu/ration ( ?is pr9ciple4 ,! top t is mo/ useful is ! gyroscope top 7,fig4 #ajc74 ,x is m\nt$ on pivots s arrang$ t ! top c turn 9 any direction )9 ! frame t supports x4 ,if ! top is set sp9n+ "o may turn ! frame 9 any direction1 b ! top does n *ange direction4 ,! axis ( ! top w po9t 9 ! same direction all ! :ile ! top is sp9n+1 no matt] h[ ! support+ frame is mov$ ab\t4 ,! top w sp9 on a /r+4 ,if atta*$ inside a box ! box c be made to /& on "o corn] :ile ! top is sp9n+4 ,illu/ration3 ,,fig4 #ajc--;,a ,,top ,,t ,,sp9s ,,on ,a ,,/r+ ,?is top1 :i* is s h>d to upset1 has be5 us$ 9 %ips to prev5t ! %ip be+ roll$ by ! waves4 ,a l>ge fly-:eel is m\nt$ 9 ! middle ( ! vessel on a horizontal axle4 ,a fly-:eel is only a l>ge top4 ,x sp9s ) a /eady motion1 & because ( its l>g] size x is v mu* h>d] to ov]turn ?an a toy top4 ,! fly-:eel 9 ! %ip resi/s ! roll+ =ce ( ! waves & /eadies ! %ip1 s t ev5 ) high waves ! roll+ c sc>cely be felt4 ,! waves d n s readily break ov] ! %ip :5 ?us /eadi$ by ! revolv+ :eel4 ,! gyroscope is also us$ 9 "s =ms ( torp$o to give ! torp$o /eady motion4 ,by means ( a spr+ releas$ by a trigg] ! gyroscope )9 ! torp$o is set sp9n+ be=e ! torp$o ent]s ! wat]4 ,! gyroscope keeps its direction un*ang$1 & z ! torp$o turns "o way or ! o!r ! gyroscope acts ^u "o or ! o!r ( two valves connect$ ) ! compress$-air *amb]s f :i* ! screws ( ! torp$o are driv54 ,! air ?us set free by ! gyroscope drives a pi/on-rod connect$ ) a rudd] 9 su* a way z to "r ! torp$o4 ,! torp$o goes ?r\gh ! wat] ) a slightly zigzag motion1 b nev] m ?an two feet out ( ! l9e 9 :i* x 0 aim$4 ,! ,monorail-,c> ,ano!r use ( ! gyroscope is 9 ! monorail-c>4 ,to make a c> run on a s+le rail1 ) its weight above ! rail1 0 impossible until ! use ( ! gyroscope 0 discov]$4 ,9 ! monorail-c> inv5t$ by ,br5nan 7,fig4 #ajd7 !re are two gyroscopes1 ea* weigh+ fifte5 hundr$ p\nds1 driv5 at a spe$ ( ?ree ?\s& revolutions a m9ute by an electric motor4 ,ea* gyroscope :eel ) its motor is m\nt$ 9 an air-tight cas+ f :i* ! air is pump$ out4 ,! :eel w run mu* m easily 9 a vacuum ?an 9 air1 = ! air (f]s v great resi/ance to its motion4 ,! :eels are plac$ "o on ea* side ( ! c> ) _! axles horizontal4 ,:5 ! c> />ts to fall ! sp9n+ gyroscopes "r x mu* z a sp9n+ top rights itself if tipp$ to "o side by a bl[4 ,if ! w9d tips ! c> to ! left ! gyroscopes incl9e to ! "r until ! c> is aga9 upright4 ,if ! load is heavi] on ! "r side ! c> incl9es itself t[>d ! left j z a man leans to ! left :5 c>ry+ a load on 8 "r %\ld]4 ,9 r\nd+ a curve ! c> leans to ! inside ( ! curve j z a bicycle rid] does1 & z a railway tra9 is made to d by lay+ ! out] rail ( ! curve high] ?an ! inn] rail4 ,two gyroscopes sp9n+ 9 opposite directions are necess>y to keep ! c> f fall+ :5 r\nd+ a curve4 ,illu/ration3 ,,fig4 #ajd--;,a ,,c> ,,t ,,runs ,,on ,,"o ,,rail ,l\is ,br5nan's full-size monorail4 ,! gyroscope may be us$ 9 place ( a compass4 ,if x is set sp9n+ 9 a nor? & s\? direction x w cont9ue to sp9 9 a nor? & s\? direction1 no matt] h[ ! %ip may turn4 ,x is ev5 m reliable ?an ! compass1 = x is n affect$ by magnetic action4 ,possibly "s ( ! great inv5tions yet to be made w be new uses ( ! sp9n+ top4 ,liquid ,air & ! ,greate/ ,cold ,= a long "t aft] m5 _h le>n$ ! use ( ! furnace & c\ld produce great heat1 ! greate/ cold kn[n 0 t ( ! m\nta9-top4 ,m5 wond]$ :at w\ld happ5 if air c\ld be made cold] ?an ! fro/ ( w9t]1 b knew n h[ to br+ ab\t su* a result4 ,!y wond]$ :at ?+s c\ld be froz5 t rema9 liquid or gase\s ev5 9 ! cold ( w9t]4 ,! fir/ artificial cold 0 produc$ by a mixture ( salt & ice1 su* z we n[ use 9 an ice-cream freez]4 ,9 "t m5 le>n$ o!r ways ( produc+ great cold & ev5 to manufacture ice 9 l>ge quantities4 ,! cold ( liquid air is f> great] ?an t ( ice or ev5 a freez+ mixture ( salt & ice4 ,liquid air is simply air t is s cold t x becomes a liquid j z /eam :5 cool$ =ms wat]4 ,/eam has only to be cool$ to ! temp]ature ( boil+ wat]1 :ile air mu/ be cool$ to #cad degrees bel[ z]o on ! ,fahr5heit scale4 ,if x 7 possible = u to live 9 su* a climate1 & ! _w 7 cool$ to ! temp]ature ( liquid air1 we %\ld h a curi\s _w4 ,wat*-spr+s might be made out ( pewt]1 bells ( t91 & piano wires ( sold]1 = ^! metals are made /rong] by ! extreme cold ( liquid air4 ,!re w\ld be no air to brea!4 ,oceans & riv]s w\ld be froz5 solid1 & ! air w\ld =m a liquid ocean ab\t ?irty-five feet deep4 ,?is ocean ( liquid air w\ld be kept boil+ a long "t by ! heat ( ! ice b5ea? x1 = ice is hot comp>$ ) liquid air4 ,! ice w\ld cool z x gave up its heat to ! liquid air & 9 "t become z cold z ! liquid air itself4 ,liquid air has be5 %ipp$ ?\s&s ( miles 9 a d\ble wall$ t9 c1 ! space betwe5 ! two walls be+ fill$ ) felt4 ,! felt protects ! liquid air f ! heat ( ! air )\t4 ,! liquid air evaporates sl[ly1 & escapes ?r\gh a small op5+ at ! top4 ,pr(essor ,dew>1 a successor ( ,f>aday 9 ! ,royal ,in/itution1 inv5t$ ! ,dew> bulb1 by means ( :i* ! evaporation ( ! liquid air is prev5t$4 ,?is bulb is a d\ble-wall$ flask4 ,9 ! space betwe5 ! two walls ( ! flask is a vacuum4 ,n[ a vacuum is ! be/ possible protection aga9/ heat4 ,if we 7 to take a bottle full ( air & pump out f ! bottle all except ab\t a ?\s&? ( a million? ( ! air x conta9$ at fir/ we %\ld h su* a vacuum z t ( ! ,dew> bulb4 ,) su* a vacuum ar\nd x ice c\ld be kept f melt+ = _m days ev5 9 ! hotte/ wea!r1 = no heat c g ?r\gh a vacuum4 ,b ! greate/ cold is n ! cold ( liquid air4 ,liquid hydrog5 is s cold t x freezes air4 ,:5 a flask ( liquid hydrog5 is op5$ !re is a small sn[-/orm ( froz5 air 9 ! m\? ( ! flask4 ,b ev5 ?is is n ! greate/ cold4 ,! liquid hydrog5 may be froz51 =m+ a hydrog5 sn[ ^: temp]ature is #dce degrees bel[ z]o4 ,?is is ne>ly equal to ! cold ( ! space beyond ! e>?'s atmosph]e1 :i* is ! greate/ possible cold4 ,! ,electric ,furnace & ! ,greate/ ,heat ,! greate/ heat t has yet be5 produc$ artificially is t ( ! electric arc4 ,! exact temp]ature ( ! electric arc is n kn[n ) c]ta9ty4 ,x is kn[n1 h[ev]1 t ! temp]ature ( ! hotte/ "p ( ! arc is n less ?an #fejj degrees ,fahr5heit4 ,:5 we comp>e ?is ) ! temp]ature ( ! hotte/ coal furnace1 :i* is ab\t #djjj degrees1 we c v easily und]/& t some?+ is likely to happ5 at ! temp]ature ( ! electric arc t c\ld n happ5 9 an ord9>y furnace4 ,if an electric arc is enclos$ by some?+ t w hold ! heat 9 we h an electric furnace1 & any sub/ance plac$ 9 ! furnace may be made ne>ly z hot z ! arc itself4 ,9 ! electric furnace any sub/ance1 :e!r f\nd 9 nature or prep>$ artificially1 may be melt$ or vaporiz$4 ,x 0 ,h5ri ,moissan1 ,pr(essor ( ,*emi/ry at ! ,sorbonne 9 ,p>is1 :o made ! fir/ great discov]ies 9 ! use ( ! electric furnace & produc$ ! fir/ artificial diamonds4 ,! /udy ( diamonds l$ ,moissan to believe t 9 nature !y are =m$ by ! cool+ ( a melt$ mixture ( iron & c>bon4 ,he c\ld prep>e su* a mixture ) 8 electric furnace1 he ?\ght1 & s make diamonds l ^? ( ! diamond m9es4 ,s1 ) an electric furnace hav+ electrodes z l>ge z a man's wri/1 a mixture ( iron & *>coal 9 a c>bon crucible1 & a glass tank fill$ ) wat]1 ,moissan set out to *ange ! *>coal to diamonds4 ,at a temp]ature ( m ?an six ?\s& degrees ! iron & *>coal 7 melt$ toge!r4 ,= a "t ( f ?ree to six m9utes ! mixture 0 9 ! int5se heat4 ,!n ! cov]+ ( ! furnace 0 remov$ & ! crucible ) ! melt$ mixture dropp$ into ! tank ( wat]4 ,) "s fe> ?is 0 done = ! fir/ "t1 = x 0 n kn[n :at w\ld happ5 :5 su* a hot object 0 dropp$ into cold wat]4 ,b no explosion occurr$1 only a viol5t boil+ ( ! wat]1 a fi]ce blaz+ ( ! molt5 mass1 & !n a gradual *ange ( color f :ite to r$ & r$ to black4 ,) boil+ acids & o!r *emicals ! refuse 0 remov$1 & ! fragm5ts t rema9$ 7 f\nd to be diamonds1 small1 x is true1 s small t !y c\ld be se5 only ) ! aid ( a microscope1 b giv+ promise ( great] ?+s to come4 ,! out] cru/ ( iron held ! melt$ *>coal "u enorm\s pressure :ile x sl[ly cool$ & =m$ ! diamond cry/als4 ,! process ( manufactur+ diamonds is illu/rat$ 9 ,figs4 #aje1 #ajf1 & #ajg4 ,illu/ration3 ,,fig4 #aje--,,manufactur+ ,,diamonds--,,fir/ ,,op]ation ,prep>+ ! furnace4 ,*>coal & iron ore plac$ 9 a crucible & subject$ to enorm\s heat electrically4 ,illu/ration3 ,,fig4 #ajf--,,manufactur+ ,,diamonds--,,second ,,op]ation ,! furnace at "w4 ,illu/ration3 ,,fig4 #ajg--,,manufactur+ ,,diamonds--,,?ird ,,op]ation ,plung+ ! crucible into cold wat]4 ,obs]ve ! :ite-hot c>bon j remov$ f ! furnace4 ,! electric furnace has made possible ! prep>ation ( sub/ances unkn[n be=e1 & ! production 9 l>ge quantities at l[ co/ ( sub/ances t be=e 7 too co/ly = g5]al use4 ,"o ( ! be/ kn[n ( ^! sub/ances is alum9um4 ,) ! discov]y ( ! electric-furnace me?od ( extract+ alum9um f its ores1 ! price ( alum9um fell f "o hundr$ & tw5ty-f\r doll>s p] p\nd to twelve c5ts p] p\nd4 ,among ! _m uses ( ! electric furnace we may m5tion ! prep>ation ( calcium c>bide1 :i* is us$ 9 produc+ ! acetyl5e light2 c>borundum1 a sub/ance almo/ z h>d z diamond2 & phosphorus1 :i* is us$ 9 mak+ ! phosphorus mat*4 ,x is us$ also to "s ext5t 9 ! manufacture ( glass1 &1 9 "s cases1 = extract+ iron f its ores4 ,! ,wireless ,telegraph ,a %ip 9 a fog is /ruck by ano!r %ip4 ,! wat] ru%es 91 puts out ! fires 9 ! boil]s1 ! eng9es /op1 ! %ip is helpless 9 mid-ocean 9 ! d>kness ( ! night4 ,b ! snapp+ ( an electric sp>k is he>d 9 "o ( ! cab9s4 ,soon ano!r vessel /eams alongside4 ,! life-boats are l[]$ & e p]son is sav$4 ,! call = help _h gone out ov] ! sea 9 e direction = two hundr$ miles4 ,ano!r %ip _h caught ! signal & ha/5$ to ! rescue1 & ! _w realiz$ t ! wireless telegraph _h robb$ ! sea ( its t]rors4 ,)\t ! curi\s comb9ation ( magnets1 wires1 & batt]ies on ! fir/ %ip no signal c\ld h be5 s5t1 & )\t su* a comb9ation on ! second %ip ! signal w\ld h pass$ unhe$$4 ,h[ 0 ?is comb9ation discov]$1 & h[ does x "w8 ,f>aday1 z we h se51 discov]$ ! pr9ciple ( ! induction-coil4 ,) ! induction-coil a p[]ful electric sp>k c be produc$4 ,! friction electrical ma*9e 0 kn[n long be=e ! "t ( ,f>aday4 ,frankl9 prov$ t a /roke ( lightn+ is l a sp>k f an electrical ma*9e1 only m p[]ful4 ,^! great discov]]s did n "k1 h[ev]1 t an electric sp>k s5ds out some?+ l light :i* travels 9 all directions4 ,!y did n "k x1 because !y _h no eyes to see ?is /range light4 ,i w tell y a fable to make ! mean+ cle>4 ,!re once liv$ a race ( bl9d m54 ,n "o ( !m c\ld see4 ,!y built h\ses & cities1 railroads & /eam%ips1 b !y did ev]y?+ by t\* & s\nd4 ,:5 !y met !y t\*$ ea* o!r & spoke1 & ea* man knew 8 fri5d by ! s\nd ( 8 voice4 ,"o day a wise man among !m said he believ$ !re 0 some?+ besides ! s\nd ( ! voice ) :i* !y c\ld make signals to ea* o!r4 ,ano!r wise man ?\ght ^u ?is matt] = "s "t & br\ght =? a pro( t !re is some?+ call$ light1 ?\gh no man c\ld see x4 ,ano!r1 wis] & m practical1 inv5t$ an eye :i* any man c\ld c>ry ab\t ) him & see ! light :5 he turn$ x 9 ! direction f :i* ! light 0 com+4 ,!reaft] ea* man c>ri$ a light t fla%$ l ! fla%+ ( a firefly4 ,ea* man also c>ri$ an eye1 & ea* c\ld see 8 fri5d z well z he> ! s\nd ( 8 voice4 ,! fable is true4 ,! light :i* no man _h se5 we n[ call electric waves4 ,! eye ) :i* any "o c p]ceive ?is light is ! receiv+ in/rum5t ( ! wireless telegraph4 ,! /range light fla%$ out :5ev] an electric sp>k pass$ f an electrical ma*9e1 a ,leyd5 j>1 an induction-coil1 or z lightn+ 9 ! cl\ds1 b = hundr$s ( ye>s ?is light 0 unse54 ,! human eye c\ld n see x1 & no artificial eye t w\ld cat* electric waves _h be5 inv5t$4 ,a man 9 ,engl&1 ,james ,cl]k-,maxwell1 fir/ prov$ t !re is su* a light4 ,he9ri* ,h]tz1 a ,g]man1 fir/ made an eye t w\ld cat* ! waves f ! electric sp>k1 & ! man :o fir/ p]fect$ an eye ) :i* "o c\ld cat* ! electric waves at a great di/ance & improv$ ! in/rum5ts = s5d+ out su* waves 0 ,m>coni4 ,! fable is true1 = electric waves are l ! light f ! sun4 ,!y g ?r\gh space 9 all directions z light does4 ,!y w n m]ely g ?r\gh air1 b ?r\gh :at we call empty space1 or a vacuum1 z light w4 ,if we ?9k ( waves some:at l wat] waves1 b n exactly l !m1 ru%+ ?r\gh space1 we h ab\t z good a picture ( electric waves z we c well =m 9 our m9ds4 ,z ! light ( a lamp goes out 9 all directions1 s d ! electric waves g out 9 all directions f ! place :]e ! electric sp>k passes4 ,s9ce ^! waves g ?r\gh :at we call empty space1 we mu/ ?9k ( some?+ 9 t space & t x is n really empty4 ,exam9e an inc&esc5t electric lamp4 ,! bulb 0 full ( air :5 ! c>bon ?read 0 plac$ 9 x4 ,! air 0 !n pump$ out until only ab\t a million? "p rema9$4 ,! bulb 0 !n seal$ at ! tip & made air-tight4 ,we say ! space inside is a vacuum4 ,if ! bulb is brok5 !re is a l\d report z ! air ru%es 94 ,is ! bulb really empty aft] ! air is pump$ out8 ,is any?+ left 9 ! bulb ar\nd ! c>bon ?read8 ,turn on ! electric curr5t & ! c>bon ?read becomes :ite hot4 ,! light f ! :ite-hot c>bon ?read goes out ?r\gh ! vacuum4 ,!re is no?+ 9 ! vacuum t we c see or feel or h&le1 b some?+ mu/ be !re to c>ry ! light f ! c>bon ?read4 ,! light ( ! sun comes to ! e>? ?r\gh n9ety-?ree million miles ( space4 ,is !re any?+ betwe5 ! e>? & ! sun ?r\gh :i* ?is light c pass8 ,light1 we "k1 is made up ( waves1 & we _c ?9k ( waves go+ ?r\gh empty space4 ,!re mu/ be some?+ betwe5 ! sun & ! e>?4 ,t some?+ ?r\gh :i* ! light ( ! sun comes to ! e>? we call ! e!r4 ,x is ! e!r t c>ries ! light across ! vacuum 9 ! light bulb z well z f ! sun to ! e>?4 ,electric waves us$ 9 wireless telegraphy g ?r\gh ?is same e!r4 ,! light ( ! sun is made up ( ! same k9d ( waves1 & we d n ?9k x /range because x is s common4 ,x is true we d n see light waves1 b !y affect our eyes s t by means ( !m we c see objects & p]ceive ! fla%+ ( a light4 ,s ) ! wireless receiv+ in/rum5t we d n see ! electric waves1 b we p]ceive ! fla%+ ( ! /range light4 ,electric waves & light travel ) ! same spe$--#ahf1jjj miles 9 a second4 ,a wireless message w g ar\nd ! e>? 9 ab\t "o-sev5? ( a second4 ,electric waves w g ?r\gh a brick wall z readily z sunlight w g ?r\gh a glass w9d[1 b t is n s /range z x may seem4 ,r$ light w n g ?r\gh blue glass4 ,blue glass holds back ! r$ light1 b lets ! blue light g ?r\gh4 ,s ! brick wall holds back common light1 b all[s ! light :i* we call electric waves to g ?r\gh4 ,"s waves on wat] are long] ?an o!rs4 ,s electric waves are long] ?an light waves4 ,t is ! only diff]5ce betwe5 !m4 ,9 fact1 ! light ( ! sun is made up ( v %ort electric waves4 ,^! %ort waves affect our eyes1 b ! long] electric waves d n4 ,we are daily receiv+ ! wireless-telegraph waves f ! sun1 :i* we call light4 ,electric waves us$ 9 wireless telegraphy v>y f ab\t six hundr$ feet to two miles 9 l5g?1 :ile ! longe/ light waves t affect our eyes are only "o ?irty-?ree-?\s&? ( an in* 9 l5g?4 ,! s5sitive "p ( ! ,m>coni receiv+ app>atus is ! coh]]4 ,! fir/ coh]] 0 made 9 #ahij by ,pr(4 ,edw>d ,branly1 ( ! ,ca?olic ,univ]sity ( ,p>is4 ,v f9e metal fil+s 7 enclos$ 9 a tube ( ebonite & connect$ 9 a circuit ) a batt]y & a galvanomet]4 ,! fil+s h s high a resi/ance t no curr5t fl[s4 ,! waves f an electric sp>k1 h[ev]1 affect ! fil+s s t !y all[ ! curr5t to fl[4 ,! electric waves are said to cause ! fil+s to coh]e--t is1 to cl+ toge!r m closely4 ,x is a peculi> =m ( electric weld+4 ,branly discov]$ t a slight tapp+ ( ! tube loos5s ! fil+s & /ops ! fl[ ( ! curr5t4 ,all t 0 ne$$ = wireless telegraphy 0 at h&4 ,m5 knew h[ to produce electric waves ( any desir$ l5g?4 ,!y knew h[ !y w\ld act4 ,a s5sitive receiv] _h be5 discov]$4 ,!re 0 ne$$ ! practical man :o %\ld comb9e ! p>ts1 improve details1 & apply ! wireless telegraph to actual use4 ,?is 0 ! "w ( ,guglielmo ,m>coni4 ,9 #ahid1 at ! age ( tw5ty1 ,m>coni began 8 exp]im5ts on 8 fa!r's e/ate1 ! ,villa ,grifone1 ,bologna1 ,italy4 ,fig4 #ajh is f a photograph ( ,m>coni & 8 wireless s5d+ & receiv+ in/rum5ts4 ,illu/ration3 ,,fig4 #ajh--,,m>coni ,,& ,,8 ,,wireless-,,telegraph ,,s5d+ ,,& ,,receiv+ ,,in/rum5ts ,to ,m>coni1 telegraph+ ?r\gh space )\t wires appe>s no m wond]ful ?an telegraph+ ) wires4 ,9 ! wire telegraph electric waves1 :i* we !n call an electric curr5t1 foll[ a wire some:at z ! s\nd ( ! voice goes ?r\gh a speak+-tube4 ,9 ! wireless telegraph ! electric waves g out ?r\gh space )\t any wire to guide !m4 ,! light & heat waves ( ! sun travel to u ?r\gh millions ( miles ( space )\t requir+ any conduct+ wire4 ,t electric waves %\ld g ?\gh space 9 ! same way t light does is no m wond]ful ?an t ! waves %\ld foll[ all ! turns ( a wire4 ,! s5d+ in/rum5t us$ by ,m>coni includes an induction-coil1 "o side ( ! sp>k-gap be+ connect$ to ! e>? & ! o!r to a v]tical wire 7,fig4 #aji74 ,!re mu/ be a batt]y ( ,leyd5 j>s 9 ! circuit ( ! second>y coil4 ,! induction-coil may be op]at$ by a /orage batt]y or dynamo4 ,! v]tical wire1 or ant5na1 is to ! s5d+ in/rum5t :at ! s\nd+-bo>d is to a viol94 ,x is ne$$ to increase ! /r5g? ( ! waves4 ,9 ! wireless telegraph "s wires mu/ be us$4 ,x is call$ wireless because ! /ations are n connect$ by wires4 ,! ant5na = long-di/ance "w consi/s ( a network ( ov]head wires4 ,:5 ! key is press$ a rapid succession ( sp>ks passes across ! sp>k-gap4 ,! ant5na1 or ov]head wire1 is ?us made to s5d out electric waves4 ,by press+ ! key = a long] or %ort] "t1 a long] or %ort] s]ies ( waves may be produc$ & a correspond+ly long] or %ort] effect on ! receiv]4 ,9 ?is mann] ! dots & da%es ( ! ,morse alphabet may be transmitt$4 ,illu/ration3 ,,fig4 #aji--;,,diagram ,,( ,,wireless-,,telegraph ,,s5d+ ,,app>atus ,at ! receiv+ /ation !re are two circuits4 ,"o includes a coh]]1 a local batt]y1 & a telegraph relay 7,fig4 #aaj74 ,! o!r circuit1 :i* is op5$ & clos$ by ! relay1 includes a record+ in/rum5t & a tapp]4 ,"o end ( ! coh]] is connect$ to ! e>? & ! o!r to a v]tical wire l t us$ = ! transmitt]4 ,! electric waves weld ! fil+s 9 ! coh]]1 & ?is closes ! fir/ circuit4 ,! relay !n closes ! second circuit1 ! record+ in/rum5t records a dot or a da%1 & ! tapp] /rikes ! coh]] & breaks ! fil+s ap>t ready = ano!r /ream ( electric waves4 ,illu/ration3 ,,fig4 #aaj--;,,diagram ,,( ,,m>coni ,,wireless-,,telegraph ,,receiv+ ,,app>atus ,! second circuit describ$ 9 ! text is n %[n "h4 ,! relay & ! second circuit w\ld take ! place ( ! electric bell4 ,9 ! circuit z %[n "h ! electric waves w\ld cause ! coh]] to close ! circuit & r+ ! bell4 ,) ?is arrangem5t x 0 possible to "w only two /ations at "o "t4 ,?\gh /ations 7 to be e/abli%$ 9 all ! cities ( ,great ,brita91 only "o message c\ld be s5t at "o "t1 & all /ations b "o mu/ keep sil5ce1 because a second s]ies ( waves w\ld m+le ) ! fir/ & confusion w\ld result4 ,m>coni's next ef=t 0 to make x possible to s5d any numb] ( messages at "o "t4 ,?is l$ to 8 sy/em ( tun+ ! s5d+ & receiv+ in/rum5ts4 ,) ?is sy/em ! receiv+ in/rum5t w take a message only f a s5d+ in/rum5t ) :i* x is 9 tune4 ,x is possible1 !re=e1 = any numb] ( wireless-telegraph /ations to op]ate at ! same "t1 ! waves cross+ "o ano!r 9 all directions )\t int]f]+1 ea* receiv] respond+ to ! waves int5d$ = x4 ,an ocean /eam] c1 ) ! tun$ sy/em1 s5d "o message & receive ano!r f a diff]5t /ation at ! same "t4 ,m>coni's ambition 0 to s5d a wireless message across ! ,atlantic4 ,quietly he made 8 prep>ation1 build+ at ,poldhu1 ,cornwall1 ,engl&1 a m p[]ful transmitt] ?an _h yet be5 us$4 ,at noon on ! #ab? ( ,decemb]1 #aija1 he sat 9 a room ( ! old b>racks on ,signal ,hill1 ne> ,/4 ,johns1 ,newf\ndl&1 wait+ = a signal f ,engl&4 ,8 assi/ants at ! ,poldhu /ation 7 to telegraph across ! ocean ! lett] ,s at c]ta9 times ea* day4 ,on ! table 0 ! receiv+ app>atus1 made v s5sitive1 & includ+ a telephone receiv]4 ,a wire l$ out ( ! w9d[ to a huge kite1 :i* ! furi\s w9d held f\r hundr$ feet above him4 ,"o kite & a balloon us$ = support+ ! ant5na _h be5 c>ri$ out to sea4 ,he held ! telephone receiv] to 8 e> = "s "t4 ,! critical "t _h come = :i* he _h work$ = ye>s1 = :i* 8 ?ree hundr$ pat5ts _h prep>$ ! way1 & = :i* 8 company _h erect$ ! co/ly p[] /ation at ,poldhu4 ,calmly he li/5$1 8 face %[+ no sign ( emotion4 ,sudd5ly !re s\nd$ ! %>p click ( ! tapp] z x /ruck ! coh]]4 ,aft] a %ort "t ,m>coni h&$ ! telephone receiv] to 8 assi/ant4 ,see if y c he> any?+1 he said4 ,a mom5t lat]1 fa9tly & yet di/9ctly1 came ! ?ree little clicks1 ! dots ( ! lett] ,s tapp$ out an in/ant be=e 9 ,engl&4 ,m>coni's victory 0 won4 ,a fly+-ma*9e c be equipp$ ) a wireless-telegraph outfit1 s t a man c telegraph :ile fly+ ?r\gh ! air4 ,two m5 are ne$$1 "o to op]ate ! fly+-ma*9e1 ! o!r to s5d ! telegraphic messages4 ,?is has be5 done ) ! ,wright ma*9e & ) "s dirigible balloons4 ,( c\rse1 ! wireless in/rum5ts on ! fly+-ma*9e _c be connect$ to ! gr\nd4 ,in/ead ( ! gr\nd connection !re is a second ant5na4--"o ant5na on ea* side ( ! sp>k-gap4 ,:ile 9 ! ord9>y wireless in/rum5ts ! dis*>ge surges back & =? betwe5 ! ant5na & ! e>?1 9 ! fly+-ma*9e wireless ! dis*>ge surges back & =? betwe5 ! two ant5n4 ,9 ! ,wright ma*9e1 :5 equipp$ = wireless telegraphy1 ! two ant5n are plac$ "o "u ! upp] plane1 ! o!r "u ! l[] plane ( ! fly+-ma*9e4 ,m p[] is requir$ = ! wireless ?an = ! wire telegraph4 ,9 ! wire telegraph ab\t "o-hundr$? horse-p[] is requir$ to s5d a message "o hundr$ & tw5ty miles4 ,to s5d a message ! same di/ance ) ! wireless requires ab\t t5 horse-p[]1 or a ?\s& times z mu* z ) ! wire telegraph4 ,?is is because 9 ! wireless telegraph ! waves g out 9 all directions1 & mu* ( ! p[] is wa/$4 ,9 ! wire telegraph ! electric waves are direct$ along ! wire & v little ( ! p[] is wa/$4 ,= ! same reason a p]son's voice c be he>d a long di/ance ?r\gh a speak+-tube4 ,! speak+-tube guides ! s\nd & prev5ts x f scatt]+ some:at z ! wire guides ! electric waves4 ,! ov]head wires ( a wireless-telegraph /ation s5d out a d>k light :ile a message is be+ s5t4 7,see frontispiece47 ,/&+ ne> ! /ation on a d>k night "o c see no?+1 b c he> only ! t]rific snapp+ ( ! electric dis*>ge4 ,! cam]a1 h[ev]1 %[s t light goes out f ! wires4 ,x is light ( %ort] waves ?an any t ! eye c p]ceive1 b ! s5sitive film ( ! photographic plate makes x kn[n to u4 ,! ,wireless ,telephone ,9 s5d+ a message by ! wire telegraph ! curr5t fl[s ov] ! l9e wire :5 ! key is press$4 ,:5 ! key is releas$ ! curr5t /ops4 ,! circuit is made & brok5 = e dot or da%4 ,?is we may call an int]rupt$ curr5t4 ,n[ we h se5 t ! attempt to inv5t a wire telephone us+ an int]rupt$ curr5t fail$4 ,:ile "o is talk+ ov] ! wire telephone a curr5t 7alt]nat+7 mu/ be fl[+ ov] ! l9e wire4 ,! s\nd ( ! voice does n make & break ! circuit1 b *anges ! /r5g? ( ! curr5t4 ,?is alt]nat+ curr5t is wond]fully s5sitive4 ,x c v>y 9 ! rate at :i* x alt]nates or ! numb] ( alt]nations p] second to correspond to s\nd ( e pit*4 ,x v>ies 9 /r5g? to correspond to all ! v>iations 9 ! voice1 & reproduces 9 ! receiv] n m]ely ! words t are spok5 b ! quality ( ! voice1 s t ! voice ( a fri5d c be recogniz$ by telephone almo/ z well z if talk+ face to face4 ,! same ?+s are true ( ! wireless telegraph & telephone4 ,in/ead ( an electric curr5t1 let u say a /ream ( electric waves4 ,!n we may say ( ! wireless ev]y?+ t we h said ( ! wire telegraph & telephone4 ,9 s5d+ a message by wireless telegraph ! /ream ( electric waves fl[s :5 ! key is press$ & /ops :5 ! key is releas$4 ,we h an int]rupt$ /ream ( electric waves4 ,b an int]rupt$ /ream ( waves _c be us$ = a wireless telephone any m ?an an int]rupt$ curr5t c be us$ = a wire-telephone4 ,!re mu/ be a con/antly fl[+ /ream ( electric waves1 & ^! waves mu/ be *ang$ 9 /r5g? & =m by ! s\nd ( ! voice4 ,fig4 #aaa %[s a wireless-telephone receiv] 9 :i* light is us$ to c>ry ! message4 ,! light acts on ! receiv] 9 su* a way z to reproduce ! s\nd4 ,illu/ration3 ,,fig4 #aaa--,,receiv] ,,( ,,bell',s ,,photophone ,an e>ly idea 9 wireless telephony4 ,9 ! wireless-telegraph receiv] ! int]rupt$ /ream ( electric waves makes & breaks ! circuit ( an electric batt]y4 ,! wireless-telephone receiv] mu/ n make & break a circuit1 b x mu/ be s5sitive to all ! *anges 9 ! electric waves4 ,"o su* receiv] is ! audion1 :i* we %all n[ describe4 ,! audion 0 inv5t$ by ,dr4 ,lee de ,=e/4 ,de ,=e/ _h tak5 ! degree ( ,doctor ( ,philosophy at ,yale ,univ]sity1 hav+ writt5 8 !sis = t degree on ! subject ( electric waves4 ,he !n ent]$ ! employ ( ! ,we/]n ,electric ,company 9 ,*icago1 & :ile 9 ?is position work$ at night 9 8 room on exp]im5ts ) electric waves4 ,"h he f\nd t a gas flame is s5sitive to electric waves 7,fig4 #aab74 ,if a gas flame is made "p ( ! circuit ( an electric batt]y1 :i* includes also an induction-coil connect$ to a telephone receiv]1 !n :5 a /ream ( electric waves comes along !re is a click 9 ! receiv]4 ,! waves *ange ! resi/ance ( ! flame1 & s *ange ! /r5g? ( ! curr5t4 ,! flame is a simple audion4 ,x is ! heat$ gas 9 ! flame t responds to ! electric waves4 ,illu/ration3 ,,fig4 #aab--;,a ,,gas ,,flame ,,is ,,s5sitive ,,to ,,electric ,,waves ,if in/ead ( a gas flame an inc&esc5t-light bulb is us$ hav+ a metal filam5t1 & on ei!r side ( ! filam5t a small /rip ( plat9um1 a m s5sitive receiv] is obta9$4 ,?is is ! audion1 :i* is ! di/+ui%+ feature ( ! ,de ,=e/ wireless telegraph & wireless telephone4 ,! metal filam5t is made :ite hot by ! curr5t f a /orage batt]y4 ,! vacuum 9 ! bulb is ab\t ! same z t ( ! ord9>y inc&esc5t electric light4 ,a v small quantity ( gas is !re=e left 9 ! bulb4 ,! electrifi$ p>ticles ( gas respond m freely to electric waves 9 ?is bulb ?an 9 ! gas flame4 ,! ,de ,=e/ wireless telephone 0 adopt$ = use 9 ! ,unit$ ,/ates ,navy %ortly be=e ! cruise ar\nd ! _w 9 #aijh4 ,e %ip 9 ! navy 0 equipp$ ) ! wireless telephone1 enabl+ ! ,admiral to talk ) ! (fic]s ( any vessel up to a di/ance ( ?irty-five miles4 ,! wireless telephone 9 use on a battle-%ip is %[n 9 ,fig4 #aac4 ,illu/ration3 ,,fig4 #aac--;,,capta9 ,,+]soll ,,on ,,bo>d ,,! ,u4 ,s4 ,,battle-,,%ip ,,connecticut ,,us+ ,,! ,,wireless ,,telephone ,wond]s ( ! ,alt]nat+ ,curr5t ,be=e ! days ( ! electric curr5t1 m5 us$ ! p[] ( fall+ wat]4 ,! mill or factory us+ ! wat]-p[] 0 plac$ beside ! fall4 ,! wat] turn$ a great :eel1 to :i* 0 connect$ ! ma*9]y ( ! mill1 ,x 0 n until ! inv5tion ( ! dynamo & motor t wat]-p[] c\ld be us$ at a great di/ance4 ,if a hundr$ ye>s ago a man _h said t ! "t w\ld come :5 a wat]fall c\ld turn ! :eels ( a mill a hundr$ miles away he w\ld h be5 laugh$ at4 ,yet ?is v ?+ has come to pass4 ,inde$1 "o wat]fall may turn ! :eels ( _m factories1 run /reet-c>s1 & light cities up to a di/ance ( a hundr$ miles & ev5 m4 ,! p[] ( ! fall+ wat] goes out ov] sl5d] copp] wires f a great dynamo ne> ! fall to ! motors 9 ! factories & /reet-c>s4 ,! fall+ wat] ( ,niag>a has ab\t five million horse-p[]4 ,ab\t ! hundr$? "p ( ?is p[] is n[ be+ us$4 ,! wat]1 fall+ 9 a :eel-pit #ada feet deep1 turns a great dynamo weigh+ #hg1jjj p\nds ) a spe$ ( #bej turns p] m9ute4 ,a numb] ( su* dynamos are us$ supply+ an alt]nat+ curr5t at a pressure ( #bb1jjj volts1 ! curr5t alt]nat+ or *ang+ direction tw5ty-five times p] second4 ,su* a pressure is too high = ! motors & electric lights1 b ! curr5t is c>ri$ at high pressure to ! place :]e x is to be us$ & !re trans=m$ to a curr5t ( l[ pressure4 ,9 c>ry+ a curr5t ov] a long l9e1 !re is less loss if ! curr5t is c>ri$ at high pressure4 ,) an alt]nat+ curr5t ?is c be done & ! curr5t *ang$ by means ( a trans=m] to a curr5t ( l[ pressure4 ,a trans=m] is simply two coils ( wire w\nd on an iron core4 ,! simple/ trans=m] is ! =m us$ by ,f>aday :5 he discov]$ electromagnetic induction4 ,if in/ead ( mak+ & break+ a circuit t fl[s only 9 "o direction z ,f>aday did1 we cause an alt]nat+ curr5t to fl[ ?r\gh "o ( ! coils1 :i* we may call ! prim>y1 ea* "t ! curr5t *anges direction 9 ! prim>y ! magnetic field is rev]s$--t is1 ! end ( ! coil :i* 0 ! nor? pole becomes ! s\? pole4 ,?is rapidly *ang+ magnetic field induces a curr5t 9 ! second>y coil4 ,ea* "t ! magnetic field ( ! prim>y coil is rev]s$ ! curr5t 9 ! second>y *anges direction4 ,?us an alt]nat+ curr5t 9 ! prim>y induces an alt]nat+ curr5t 9 ! second>y4 ,"o ( ^! coils is ( f9e wire1 :i* is w\nd a great _m times ar\nd ! iron4 ,! o!r is ( co>s] wire w\nd only a few times ar\nd ! iron4 ,suppose ! curr5t is to be *ang$ f high pressure to l[ pressure4 ,!n ! high-pressure curr5t f ! l9e is made to fl[ ?r\gh ! coil ( _m turns1 & a curr5t ( l[ pressure is giv5 out f ! coil ( few turns4 ,by *ang+ ! numb] ( turns ( wire 9 ! coils we c make ! pressure :atev] we please4 ,if ! pressure or voltage ( ! second>y coil is less ?an t ( ! prim>y1 we h a /ep-d[n trans=m]4 ,on ! o!r h&1 if we s5d ! curr5t f ! l9e wire ?r\gh ! coil ( few turns1 !n we get a high] voltage f ! second>y coil ?an t ( ! l9e wire1 & we h a /ep-up trans=m]4 ,! ,niag>a curr5t is /epp$ d[n f #bb1jjj volts to #bbj volts = use 9 motors4 ,an electric lamp may be light$ ?\gh n connect$ to any batt]y or dynamo1 b connect$ only to a coil ( wire 7,fig4 #aad74 ,m ?an ?is1 ! coil may be insulat$ s t no curr5t c ent] x f any o!r coil or wire1 & yet ! lamp c be light$4 ,?is c be done only by means ( an alt]nat+ curr5t4 ,if ! coil to :i* ! lamp is connect$ is held 9 ! magnetic field ( an alt]nat+ curr5t1 !n ano!r alt]nat+ curr5t is induc$ 9 ! coil1 & ?is second curr5t fl[s ?r\gh ! lamp4 ,illu/ration3 ,,fig4 #aad--;,,inc&esc5t ,,electric ,,lamp ,,light$ ,,?\gh ,,n ,,connect$ ,,to ,,any ,,batt]y ,,or ,,dynamo ,we h already le>n$ t a *ang+ magnetic field induces a curr5t 9 a coil4 ,n[ ! coil ?r\gh :i* an alt]nat+ curr5t is fl[+ has a *ang+ magnetic field all ar\nd x1 & if ! lamp-coil is br\ght into ?is *ang+ magnetic field an alt]nat+ curr5t w fl[ ?r\gh ! coil & ! lamp4 ,! insulation on ! lamp-coil does n prev5t ! magnetic field f act+1 ?\gh x does prev5t a curr5t f ent]+ ! coil4 ,! curr5t is induc$ 9 ! coil itself1 & does n ent] x f any outside s\rce4 ,! trans=m] works 9 ! same way1 ! only diff]5ce be+ t 9 ! trans=m] ! two coils are on ! same iron core4 ,b 9 ! trans=m] ! two coils are insulat$ s t no curr5t c fl[ f "o coil to ! o!r4 ,:5 an alt]nat+ curr5t & trans=m]s are us$1 ! curr5t t lights ! lamps 9 ! h\ses or on ! /reets is n ! curr5t f ! dynamo4 ,x is a new curr5t induc$ 9 ! second>y coil ( ! trans=m] by ! magnetic field ( ! prim>y coil4 ,a peculi> trans=m] :i* produces an alt]nat+ curr5t t *anges direction millions ( times 9 a second has be5 made by ,nikola ,tesla4 ,?is curr5t w d _m wond]ful ?+s :i* no ord9>y curr5t w d4 ,x w light a room or run a motor )\t connect+ wires4 ,x has produc$ an electric dis*>ge sixty-five feet 9 l5g? 7,figs4 #aae & #aaf74 ,?\gh ?is curr5t is caus$ to fl[ by a pressure ( millions ( volts1 x may be tak5 ) safety ?r\gh ! human body4 ,/range z x may seem1 ! safety ( ?is curr5t is due to ! high pressure & ! rapidity ) :i* x *anges direction4 ,:ile ! curr5t us$ at ,s+ ,s+ 9 execut+ crim9als has a pressure ( ab\t tw5ty-five hundr$ volts1 a curr5t hav+ a pressure ( a million volts & alt]nat+ hundr$s ( ?\s&s or millions ( times p] second is h>mless2 ,) su* a curr5t ! human body may become a live wire1 & an electric lamp to be light$ held 9 "o h& :ile ! o!r h& grasps ! wire f ! trans=m]4 ,illu/ration3 ,,fig4 #aae--;,,an ,,electric ,,dis*>ge ,,at ,a ,,pressure ,,( #ab1jjj1jjj ,,volts1 ,a ,,curr5t ,,( #hjj ,,amp]es ,,9 ,,! ,,second>y ,,coil ,illu/ration3 ,,fig4 #aaf4--;,,an ,,electric ,,dis*>ge ,,sixty-,,five ,,feet ,,9 ,,l5g? ,x-,rays & ,radium ,a /range light :i* passes ?r\gh ! human body z readily z sunlight ?r\gh a w9d[ 0 discov]$ by ,pr(4 ,wilhelm ,konrad ,ro5tg51 ( ! ,univ]sity ( ,wrzburg4 ,?is light1 :i* ,pr(essor ,ro5tg5 nam$ ,x-rays1 is giv5 out :5 an electric dis*>ge at high pressure passes ?r\gh a c]ta9 k9d ( glass tube f :i* ! air has be5 pump$ out until !re is a ne>ly p]fect vacuum4 ,x-rays 7 discov]$ by accid5t4 ,pr(essor ,ro5tg5 0 work+ at 8 desk ) "o ( ! glass tubes :5 he 0 call$ to lun*4 ,he laid ! tube ) ! electric dis*>ge pass+ ?r\gh x on a book4 ,return+ f lun* he took a photographic plate-hold] :i* 0 "u ! book & made "s outdoor exposures ) 8 cam]a4 ,on develop+ ! plates a picture ( a key appe>$ on "o ( !m4 ,he 0 greatly puzzl$ at fir/1 b aft] a se>* = ! key f\nd x betwe5 ! leaves ( ! book4 ,! /range light f ! electric dis*>ge 9 ! glass tube _h pass$ ?r\gh ! book & ! h>d-rubb] slide ( ! plate-hold] & made a %ad[-picture ( ! key on ! photographic plate4 ,he tri$ ! /range light 9 _m ways1 & f\nd t x w\ld g ?r\gh _m objects4 ,x w\ld ev5 g ?r\gh ! human body1 s t %ad[-pictures ( ! bones & organs ( ! body c\ld be obta9$4 ,9 ,fig4 #aag is %[n a physician us+ ,x-rays4 ,fig4 #aah is an ,x-ray photograph ( ! eye4 ,illu/ration3 ,,fig4 #aag--;,a ,,physician ,,exam9+ ,,! ,,bones ,,( ,,! ,,arm ,,by ,,means ,,( ,x-,,rays ,illu/ration3 ,,fig4 #aah--,x-,,ray ,,photograph ,,( ,,! ,,eye ,! eye is above & to ! left ( ! l>g] black circle4 ,! small] black circle is a %ot :i* has lodg$ back ( ! eye4 ,n long aft] ! discov]y ( ,x-rays x 0 discov]$ t light v mu* l ! ,x-rays is giv5 out by c]ta9 m9]als4 ,"o ( ! mo/ int]e/+ & ! be/ kn[n ( ^! is radium4 ,radium gives out a light some:at l ,x-rays t w g ?r\gh copp] & o!r metals4 ,x does _m o!r /range ?+s4 ,x gives out heat z well z light2 s mu* heat1 9 fact1 t x is always ab\t five degrees w>m] ?an ! air ar\nd x4 ,x cont9ues to give out heat at su* a rate t a p\nd ( radium w melt a p\nd ( ice e h\r4 ,x c probably keep ?is up = at lea/ a ?\s& ye>s4 ,if ?is heat c\ld be us$ 9 runn+ an eng9e1 a hundr$ p\nds ( radium w\ld run a "o-horse-p[] eng9e )\t /opp+ = _m hundr$ ye>s4 ,! p[] ( ,niag>a might be replac$ by ! p[] ( radium if an eng9e t c\ld use ?is p[] 7 inv5t$4 ,fig4 #aai is f a photograph made ) radium4 ,illu/ration3 ,,fig4 #aai--,,photograph ,,made ,,) ,,radium ,a purse conta9+ a co94 ,! /range light f ! radium goes ?r\gh ! purse & ! slide ( ! plate-hold] & makes a %ad[-picture4 ,! great inv5tor ( ! future may be able to use ! heat ( radium or "s new p[] n[ unkn[n4 ,we h se5 h[1 ?r\gh ! toil ( _m ye>s & ! labors ( _m m51 ! great inv5tions ( our age h come into be+4 ,x may be t we are n[ witness+ o!r great inv5tions 9 ! mak+4 ,,app5dix ,,brief ,,notes ,,on ,,important ,,inv5tions ,a]ial ,navigation ,fir/ air balloon--,montgolfi] ,bro!rs1 ,france1 #aghc4 ,fir/ balloon asc5sion--,rozi]1 ,france1 #aghc4 ,fir/ gas balloon--,*>les1 ,france1 #aghc4 ,fir/ cross+ ( ! ,engli% ,*annel 9 a balloon--,blan*>d1 #aghe4 ,fir/ successful dirigible balloon--,la ,france1 ,r5>d & ,krebs1 ,france1 #ahhd4 ,fir/ successful motor-driv5 a]oplane--,wright ,bro!rs1 ,unit$ ,/ates2 date ( pat5t1 #aijf4 ,fir/ cross+ ( ! ,engli% ,*annel by an a]oplane--,blriot1 #aiji4 ,fir/ air-%ip 9 regul> pass5g] s]vice--,c\nt ,zeppel91 ,g]many1 #aiaj4 ,agriculture ,pl\gh ) ca/-iron mold-bo>d & iron %>es--,james ,small1 ,scotl&1 #aghd4 ,gra9-?re%+ ma*9e--,&rew ,meikle1 ,engl&1 #aghh4 ,mc,cormick reap]1 fir/ practical gra9-h>ve/+ ma*9e--,cyrus ,h4 ,mc,cormick1 ,unit$ ,/ates1 #ahca4 ,self-rak] = h>ve/]s--,mc,cormick1 #ahde4 ,incl9$ plat=m & elevator 9 ! reap]1 to enable m5 b9d+ ! gra9 to ride ) ! ma*9e--,j4 ,s4 ,m>%1 ,unit$ ,/ates1 #aheh4 ,b>b$-wire f5ce introduc$--,unit$ ,/ates1 #ahfa4 ,self-b9d]1 fir/ automatic gra9-b9d+ device = ! reap]--,jacob ,behel1 ,unit$ ,/ates1 #ahfd4 ,sulky pl\gh--,b4 ,sluss]1 ,unit$ ,/ates1 #ahfh4 ,tw9e-b9d] = h>ve/]s--,m4 ,l4 ,gorham1 ,unit$ ,/ates1 #ahgc4 ,improv$ self-b9d+ reap]--,lock & ,wood1 ,unit$ ,/ates1 #ahgc4 ,b>b$-wire ma*9e--,glidd5 & ,vaughn1 ,unit$ ,/ates1 #ahgd4 ,rot>y disk cultivator--,mallon1 ,unit$ ,/ates1 #ahgh4 ,/eam-pl\gh--,w4 ,foy1 ,unit$ ,/ates1 #ahgi4 ,comb9$ h>ve/] & ?re%]--,matteson1 ,unit$ ,/ates1 #ahhf4 ,automobile m[]--,de]+ ,h>ve/or ,company1 ,unit$ ,/ates1 #aija4 ,automobile ,fir/ /eam-automobile--,cugnot1 ,france1 #agfi4 ,fir/ *a9 transmission ( p[] 9 an automobile--,gurney1 ,engl&1 #ahbi4 ,application ( gas-eng9e to road vehicles1 beg9n+ ( ! mod]n motor-c>--,gottlieb ,daiml] & ,c>l ,b5z work+ indep5d5tly1 ,g]many1 #ahhf4 ,daiml]'s inv5tion consi/$ ( a two-cyl9d] air-cool$ motor4 ,x 0 tak5 up 9 #ahhi1 by ,panh>d & ,levassor1 ( ,p>is1 :o began imm$iately ! con/ruction ( ! motor-c>4 ,?is 0 ! beg9n+ ( ! motor-c> indu/ry4 ,bicycle ,fir/ bicycle--,bran*>d & ,maguri]1 ,france1 #aggi4 ,re>-driv5 *a9 safety bicycle--,george ,w4 ,m>ble1 ,unit$ ,/ates1 #ahhd4 ,bicycles fir/ equipp$ ) pneumatic tires--#ahij4 ,electrical ,inv5tions ,william ,gilb]t1 ,engl&1 #aedj-afjc1 call$ ! fa!r ( magnetic philosophy1 fir/ to use ! t]ms electric =ce1 electric attraction1 magnetic pole4 ,fir/ electrical ma*9e1 a ma*9e = produc+ electricity by friction--,otto von ,gu]icke1 ,g]many1 ab\t #afha4 ,discov]y ( conductors & insulators--,/eph5 ,gray1 ,engl&1 #afif-agcf4 ,fir/ to discov] t electric *>ges are ( two k9ds--,ci/]nay du ,fay1 ,france1 #afih-agci2 ,du ,fay 0 also ! fir/ to attempt an explanation ( electrical action4 ,he suppos$ t electricity consi/s ( two fluids :i* are sep>at$ by friction1 & :i* neutralize ea* o!r :5 !y comb9e4 ,?is !ory 0 m fully set =? by ,rob]t ,symm]4 ,leyd5 j>--,discov]$ fir/ by ,von ,klei/ 9 #agde4 ,! same discov]y 0 made & ! ,leyd5 j> br\ght to ! att5tion ( ! public 9 #agdf by ,piet] van ,muss*5broek 9 ,holl&4 ,lightn+-rod--,b5jam9 ,frankl91 #agcb4 ,electroplat+--,luigi ,brugnatelli1 ,italy1 #ahje4 ,voltaic arc1 a p[]ful arc light produc$ ) a batt]y curr5t--,sir ,humphry ,davy1 ,engl&1 #ahjh4 ,/orage batt]y--,ritt]1 ,g]many1 #ahjc4 ,plat9um wires 7 dipp$ 9 wat] & a batt]y curr5t pass$ ?r\gh4 ,hydrog5 collect$ on "o wire & oxyg5 on ! o!r4 ,if ! plat9um wires 7 disconnect$ f ! batt]y & connect$ ) ea* o!r by a conductor1 ! two wires act$ l ! plates ( a batt]y1 & a curr5t w\ld fl[ = a %ort "t 9 ! new circuit4 ,electromagnetism discov]$--,h4 ,c4 ,o]/$1 ,d5m>k1 #ahai4 ,galvanomet]1 a coil ( wire ar\nd a magnetic ne$le = measur+ ! /r5g? ( an electric curr5t--,s*weigg]1 ,g]many1 #ahbj4 ,motion ( magnet produc$ by an electric curr5t--,m4 ,f>aday1 ,engl&1 #ahba4 ,!rmo-electricity1 an electric curr5t produc$ by heat+ ! junction ( two unlike metals--,discov]$ by ,pr(essor ,seebeck ,engl&1 #ahba4 ,pr9ciples ( electrodynamics1 motion produc$ by an electric curr5t--,ampre1 ,france4 ,ann\nc$ 9 #ahbc4 ,law ( electric circuits1 ,ohm's law1 curr5t /r5g? equals electromotive =ce divid$ by resi/ance ( ! circuit--,george ,s4 ,ohm1 ,g]many4 ,prov5 by exp]im5t 9 #ahbf2 ma!matical pro( publi%$ 9 #ahbg4 ,magneto-electric induction1 induction ( electric curr5ts by means ( a magnetic field--,m4 ,f>aday1 ,engl&1 #ahca4 ,electric telegraph--,pr(4 ,s4 ,f4 ,b4 ,morse1 ,unit$ ,/ates1 #ahcb4 ,fir/ telegram s5t 9 #ahdd--,morse4 ,con/ant electric batt]y--,j4 ,p4 ,daniell1 ,engl&1 #ahcf4 ,fir/ electric motor-boat--,jacobi1 ,russia1 #ahci4 ,induction-coil--,rhumkorff1 ,g]many1 #ahea4 ,duplex telegraph1 fir/ practical sy/em--,/e>ns1 ,unit$ ,/ates1 ab\t #ahee-ahfj4 ,/orage batt]y1 lead plates 9 sulphuric acid--,ga/on ,plant1 ,france1 #ahei4 ,telephone1 make-&-break sy/em1 fir/ electrical transmission ( spee*--,philip ,reiss1 ,g]many1 #ahfj4 ,atlantic cable laid--,cyrus ,w4 ,field1 #ahff4 ,dynamo1 armature coil rotates 9 ! field ( an electromagnet1 armature supplies curr5t = ! electromagnet z well z = ! ext]nal circuit--,william ,siem5s1 ,g]many1 #ahff4 ,gramme r+ armature = dynamo--,gramme1 ,france1 #ahfh4 ,!ory t light consi/s ( electromagnetic waves--,cl]k-,maxwell1 ,engl&1 #ahgc4 ,quadruplex telegraph1 s5d+ f\r messages ov] "o wire at ! same "t--,edison1 #ahgc4 ,siphon record] = subm>9e telegraph1 s5sitive to v feeble curr5ts--,sir ,william ,?omson1 ,engl&1 #ahgd4 ,telephone1 v>y+ curr5t1 fir/ practical work+ telephone--,alex&] ,graham ,bell1 ,unit$ ,/ates1 #ahgf4 ,electric c&le1 beg9n+ ( pres5t arc light--,paul ,jablo*k(f1 ,russia1 #ahgf4 ,telephone transmitt] ( v>iable resi/ance--,emil ,b]l9] & ,edison work+ indep5d5tly1 ,unit$ ,/ates1 #ahgg4 ,edison us$ c>bon contacts1 ,b]l9] us$ metal contacts4 ,bru% sy/em ( arc light+--#ahgh4 ,inc&esc5t electric lamp ) c>bon filam5t--,edison1 #ahgh4 ,fir/ electric locomotive--,siem5s1 ,g]many1 #ahgi4 ,blake telephone transmitt]--,blake1 ,unit$ ,/ates1 #ahhj4 ,/orage batt]y1 lead grids fill$ ) active mat]ial--,faure1 ,france1 #ahha4 ,electric ,weld+--,elihu ,?ompson1 ,unit$ ,/ates1 #ahhf4 ,electric ,waves discov]$ by exp]im5t--,he9ri* ,h]tz1 ,g]many1 #ahhh4 ,coh]] = receiv+ electric ,waves--,edw>d ,branly1 ,france1 #ahij4 ,x-rays--,discov]$ by ,pr(4 ,w4 ,c4 ,ro5tg51 ,g]many2 ann\nc$ to ! public 9 #ahie4 ,wireless telegraphy--,g4 ,m>coni1 ,italy1 #ahif4 ,n]n/ electric light1 a clay capable ( conduct+ electricity :5 heat$ is us$2 x becomes inc&esc5t )\t a vacuum--,walt] ,n]n/1 ,g]many1 #ahig4 ,radium discov]$ by ,madame ,curie1 ,france1 #ahih4 ,explosives ,gunp[d]--,inv5tor & date unkn[n4 ,guncotton--,s*nbe91 ,g]many1 #ahde4 ,nitroglyc]9e--,sobr]o1 #ahdg4 ,explosive gelat9e--,a4 ,nobel1 ,france1 #ahfc4 ,dynamite--,a4 ,nobel1 ,france1 #ahff4 ,smokeless p[d]--,vielle1 ,france1 #ahff4 ,fire>ms & ,ordnance ,spirally groov$ rifle b>rel--,ko/]1 ,engl&1 #afbj4 ,bree*-load+ %ot-gun--,?ornton & ,hall1 ,unit$ ,/ates1 #ahaa4 ,! revolv]2 a device = comb9+ a numb] ( long b>rels s z to rotate ^u a sp9dle by ! act ( cock+ ! hamm]--,samuel ,colt1 ,unit$ ,/ates1 #ahcf4 ,bree* gun-lock1 int]rupt$ ?read--,*amb]s1 ,unit$ ,/ates1 #ahdi4 ,magaz9e gun--,walt] ,hunt1 ,unit$ ,/ates1 #ahdi4 ,bree*-load+ rifle--,mayn>d1 ,unit$ ,/ates1 #ahea4 ,iron-clad float+ batt]ies fir/ us$ 9 ,crimean ,w>--#ahee4 ,bree*-load+ ordnance--,wright & ,g\ld1 ,unit$ ,/ates1 #aheh4 ,revolv+ turret = float+ batt]ies--,!odore ,timby1 ,unit$ ,/ates1 #ahfb4 ,fir/ iron-clad float+ batt]y propell$ by /eam3 ! ,monitor--,john ,ericsson1 ,unit$ ,/ates1 #ahfb4 ,gatl+ gun--,dr4 ,r4 ,j4 ,gatl+1 ,unit$ ,/ates1 #ahfb4 ,automatic %ell-ejector = revolv]--,w4 ,c4 ,dodge1 ,unit$ ,/ates1 #ahfe4 ,torp$o--,:itehead1 ,unit$ ,/ates1 #ahff4 ,disappe>+ gun-c>riage--,moncrief1 ,engl&1 #ahfh4 ,reb\nd+ gun-lock--,l4 ,hail]1 ,unit$ ,/ates1 #ahgj4 ,magaz9e rifle--,lee1 ,unit$ ,/ates1 #ahgi4 ,hamm]less gun--,gre5]1 ,unit$ ,/ates1 #ahhj4 ,gun sil5c]1 to be atta*$ to b>rel ( gun2 gun c be fir$ )\t noise--,maxim1 #aiji4 ,gas ,us$ = ,light & ,p[] ,gas fir/ us$ = illum9at+ purposes--,william ,murdo*1 ,engl&1 #agib4 ,fir/ /reet gas-light+ 9 ,engl&--,f4 ,a4 ,w9sor1 #ahad4 ,gas-met]--,s4 ,clegg1 ,engl&1 #ahae4 ,wat]-gas1 prep>$ by pass+ /eam ov] :ite-hot an?racite coal--,fir/ produc$ 9 ,engl& 9 #ahbc4 ,illum9at+ wat]-gas--,l[e1 ,unit$ ,/ates1 #ahge4 ,gas-eng9e1 #d-;cycle1 beg9n+ ( mod]n gas-eng9e--,otto & ,lang51 ,g]many1 #ahgg4 ,inc&esc5t gas-mantle--,c>l ,a4 von ,welsba*1 ,au/ria1 #ahhg4 ,iron & ,/eel ,bla/-furnace1 beg9n+ ( iron indu/ry--,belgium1 #acdj4 ,use ( coke 9 bla/-furnace--,abram ,d>by1 ,engl&1 ab\t #agbj4 ,puddl+ iron--,h5ry ,cort1 ,engl&1 #aghc-hd4 ,process ( mak+ malleable-iron ca/+s--,lucas1 ,engl&1 #ahjd4 ,hot-air bla/ = iron furnaces--,j4 ,b4 ,neilson1 ,scotl&1 #ahbh4 ,! galvaniz+ ( iron--,h5ry ,craufurd1 ,engl&1 #ahcg4 ,process ( mak+ /eel1 bl[+ air ?r\gh molt5 pig-iron to burn out c>bon1 !n add+ spiegel iron2 fir/ production ( *eap /eel--,sir ,h5ry ,bessem]1 ,engl&1 #ahee4 ,reg5]ative furnace1 a gas-furnace 9 :i* gas & air are heat$ be=e be+ introduc$ into ! furnace1 giv+ an extremely high temp]ature--,william ,siem5s1 ,engl&1 #ahef4 ,op5-he>? process ( mak+ /eel--,siem5s-,m>t91 ,engl&1 #ahef4 ,nickel /eel1 mu* /rong] ?an ord9>y /eel1 us$ = armorplate--,s*neid]1 ,unit$ ,/ates1 #ahhi4 ,m9+ ,m9]s' safety-lamp--,sir ,humphry ,davy1 ,engl&1 #ahae4 ,compress$-air rock-drill--,c4 ,burleigh1 ,unit$ ,/ates1 #ahff4 ,diamond rock-drill1 a tube ( ca/-/eel ) a numb] ( black diamonds set at "o end4 ,! ma*9e cuts a circul> groove1 leav+ a core inside ! tube4 ,?is core is br\ght to ! surface ) a rod1 & ! p[d]$ rock is wa%$ out by wat] =c$ d[n ! tube & fl[+ up ! sides ( ! hole4 ,! drill does n h to /op = clean+ out--,h]man1 ,unit$ ,/ates1 #ahed4 ,photography ,fir/ photographic picture1 n p]man5t--,?omas ,w$gewood1 ,engl&1 #agia4 ,dagu]reotype1 fir/ develop+ process--,l\is ,dagu]re1 ,france1 #ahci4 ,fir/ photographic portraits1 dagu]reotype process--,pr(4 ,j4 ,w4 ,drap]1 ,unit$ ,/ates1 #ahci4 ,collodion process 9 photography--,scott ,ar*]1 ,engl&1 #ahdi4 ,photographic roll films--,melhui%1 ,engl&1 #ahed4 ,dry-plate photography--,dr4 ,j4 ,m4 ,taup5ot1 #ahee4 ,photographic emulsion1 bromide ( silv] 9 gelat9e1 basis ( pres5t rapid photography--,r4 ,l4 ,maddox1 ,engl&1 #ahga4 ,h& photographic cam]a = plates--,william ,s*mid1 ,unit$ ,/ates1 #ahha4 ,pr9t+ ,fir/ pr9t+ ) movable types 9 ,europe & fir/ pr9t+-press--,gutt5b]g1 ,g]many1 ab\t #adde4 ,screw pr9t+-press--,blaew1 ,g]many1 #afbj4 ,fir/ newspap] ( importance--,london ,weekly ,c\rant1 #afbe4 ,/]eotyp+1 mak+ plates f ca/s ( ! type aft] x is set up--,william ,g$1 ,scotl&1 #agca4 ,fir/ practical /eam rot>y pr9t+-press1 pap] pr9t$ on bo? sides1 #ahjj impressions p] h\r--,fr$]ick ,ko5ig1 ,g]many1 #ahad4 ,pr9t+ f curv$ /]eotype plates--,h4 ,c[p]1 ,engl&1 #ahae4 ,hoe's lightn+ press1 #bjjj impressions p] h\r--,r4 ,hoe1 ,unit$ ,/ates1 #ahdg4 ,pr9t+ f a cont9u\s web1 pap] w\nd 9 rolls1 bo? sides pr9t$ at once--,william ,bullock1 ,unit$ ,/ates1 #ahfe4 ,/raightl9e newspap] p]fect+ press1 pr9ts #ajj1jjj eight-page pap]s p] h\r--,goss ,company1 ,unit$ ,/ates4 ,l9otype ma*9e4 ,! op]ator uses a keybo>d l t ( a typewrit]4 ,! ma*9e sets ! matrices :i* correspond to ! type1 ca/s ! type 9 l9es f molt5 metal1 deliv]s ! l9es ( type on a galley1 & returns ! matrices to _! appropriate tubes4 ,x does ! "w ( five m5 sett+ type 9 ! ord9>y way--,o?m> ,m]g5?al]1 ,unit$ ,/ates1 #ahij4 ,/eam ,navigation ,fir/ /eamboat 9 ! _w--,pap91 ,riv] ,fulda1 ,g]many1 #agje4 ,fir/ /eamboat 9 ,am]ica--,john ,fit*1 ,delaw>e ,riv]1 #aghc4 ,fir/ pass5g] /eamboat 9 ! _w1 ! ,cl]mont--,rob]t ,fulton1 ,hudson ,riv]1 #ahjg4 ,fir/ /eam] to cross ! ,atlantic1 ! ,savannah1 built at ,new ,york--,fir/ voyage across ! ,atlantic1 #ahai4 ,! screw propell] fir/ us$ on a /eamboat--,john ,ericsson1 ,unit$ ,/ates1 ab\t #ahcf4 ,comp\nd eng9es adopt$ = /eam]s--#ahef4 ,fir/ turb9e-/eam]1 ! ,turb9ia--,p>sons1 #ahie4 ,fir/ m]cantile /eam-turb9e %ip1 ! ,k+ ,edw>d--,d5ny & ,bro!rs1 ,engl&1 #aija4 ,/eam ,us$ = ,p[] & ,l& ,transportation ,fir/ /eam-eng9e ) a pi/on--,d5ys ,pap91 ,france1 #afij4 ,fir/ practical application ( ! p[] ( /eam1 pump+ wat]--,?omas ,sav]y1 ,engl&1 #afih4 ,d\ble-act+ /eam-eng9e & cond5s]--,james ,watt1 ,scotl&1 #aghb4 ,/eam-locomotive fir/ us$ to haul loads on a railroad--,ri*>d ,treve?ick1 ,engl&1 #ahjd4 ,fir/ pass5g] /eam railway1 ! ,/ockton ,d>l+ton--,george ,/eph5son1 ,engl&1 #ahbe4 ,fir/ /eam-locomotive 9 ! ,unit$ ,/ates1 ! ,/\rbridge ,lion--#ahbi4 ,l9k motion = locomotives--,george ,/eph5son1 ,engl&1 #ahcc4 ,/eam-:i/le1 adopt$ = use on locomotives--,george ,/eph5son1 #ahcc4 ,/eam-hamm]--,james ,nasmy?1 ,scotl&1 #ahdb4 ,/eam-pressure gauge--,b\rdon1 ,france1 #ahdi4 ,corliss eng9e--,g4 ,h4 ,corliss1 ,unit$ ,/ates1 #ahdi4 ,fir/ practical /eam-turb9e--,c4 ,a4 ,p>sons1 ,engl&1 #ahhd4 ,textile ,indu/ries ,fly+ %uttle1 fir/ important inv5tion 9 weav+1 lead+ to mod]n weav+ ma*9]y--,john ,kay1 ,engl&1 #agcc4 ,sp9n+-j5ny--,james ,h>greaves1 ,engl&1 #agfc4 ,p[] loom--,james ,c>twright1 ,engl&1 #aghe4 ,cotton-g91 = sep>at+ ! se$s f ! fibre1 gave a new impetus to ! cotton indu/ry4 ,! production ( cotton increas$ 9 five ye>s f #ce1jjj to #aee1jjj bales--,eli ,:itney1 ,unit$ ,/ates1 #agib4 ,patt]n loom1 = ! weav+ ( patt]ns--,m4 ,j4 ,jacqu>d1 ,france1 #ahja4 ,application ( /eam to ! loom--,william ,horrocks1 ,engl&1 #ahjc4 ,knitt+-ma*9e--,brunel1 ,engl&1 #ahaf4 ,sew+-ma*9e--,elias ,h[e1 ,unit$ ,/ates1 #ahdf4 ,m]c]iz$ cotton--,john ,m]c]1 ,engl&1 #ahej4 ,process ( mak+ artificial silk--,h4 de ,*>donnet1 ,france1 #ahhh4 ,wood-,work+ ,circul> wood-saw--,mill]1 ,engl&1 #aggg4 ,wood-plan+ ma*9e--,samuel ,b5!m1 ,engl&1 #agia4 ,wood-mortis+ ma*9e--,m4 ,j4 ,brunel1 ,engl&1 #ahja4 ,b& wood-saw--,newb]ry1 ,engl&1 #ahjh4 ,la! = turn+ irregul> wood =ms--,?omas ,blan*>d1 ,unit$ ,/ates1 #ahai4 ,improv$ plan+-ma*9e--,william ,woodwor?1 ,unit$ ,/ates1 #ahbh4 ,miscellane\s ,fir/ firepro( safe--,ri*>d ,scott1 ,engl&1 #ahja4 ,/eel p51 quill p5 us$ up to ?is "t--,wise1 ,engl&1 #ahjc4 ,fir/ life-pres]v]--,john ,edw>ds1 ,engl&1 #ahje4 ,calculat+ ma*9e--,*>les ,babbage1 ,engl&1 #ahbb4 ,fir/ friction mat*es--,john ,walk]1 ,unit$ ,/ates1 #ahbg4 ,fl9t & /eel 7 us$ = />t+ fires be=e mat*es 7 inv5t$4 ,fir/ portable /eam fire-eng9e--,bri?waite & ,ericsson1 ,engl&1 #ahcj4 ,vulcaniz+ ( rubb]--,*>les ,goodye>1 ,unit$ ,/ates1 #ahci4 ,pneumatic tire--,r4 ,w4 ,?ompson1 ,engl&1 #ahde4 ,"t-lock = safes--,savage1 ,unit$ ,/ates1 #ahdg4 ,mat*-mak+ ma*9]y--,a4 ,l4 ,d5ison1 ,unit$ ,/ates1 #ahej4 ,am]ican ma*9e-made wat*es--,unit$ ,/ates1 #ahej4 ,safety mat*es--,lund/rom1 ,sw$51 #ahee4 ,sleep+-c>--,woodruff1 ,unit$ ,/ates1 #ahef4 ,pr9t+-ma*9e = ! bl9d1 orig9 ( ! typewrit]--,alfr$ ,e4 ,bea*1 ,unit$ ,/ates1 #ahef4 ,cable-c>--,e4 ,a4 ,g>dn]1 ,unit$ ,/ates1 #aheh4 ,driv5 well1 an iron tube ) ! end po9t$ & p]=at$ driv5 into ! gr\nd--,col4 ,n4 ,w4 ,gre51 ,unit$ ,/ates1 #ahfa4 ,pass5g] elevator--,e4 ,g4 ,otis1 ,unit$ ,/ates1 #ahfa4 ,fir/ practical typewrit]--,c4 ,l4 ,%oles1 ,unit$ ,/ates1 #ahfa4 ,railway air-brake1 use ( air-pressure 9 apply+ brakes to ! :eels ( a c>4 ,a /rong spr+ presses ! brake aga9/ ! :eels4 ,air acts aga9/ ! spr+ & holds ! brake away f ! :eels4 ,to apply ! brake1 air is all[$ to escape1 r$uc+ ! pressure & all[+ ! spr+ to act--,george ,we/+h\se1 ,unit$ ,/ates1 #ahfi4 ,/ore-ca% c>ri]--,dr4 ,br[n1 ,unit$ ,/ates1 #ahge4 ,roll] fl\r-mills--,f4 ,wegman1 ,unit$ ,/ates1 #ahge4 ,k9etoscope1 mov+-picture ma*9e--,edison1 #ahic4 ,,index ,a]oplane1 #ahd4 ,air-pressure1 #bc4 ,air-pump1 #bj4 ,air-%ips1 #agc4 ,air !rmomet]1 #ac4 ,alt]nat+ curr5t1 wond]s (1 #bbe4 ,amb]1 #h4 ,ampre1 #fg1 #aaa4 ,arago1 #fi4 ,ar*im$es1 #a1 #ab2 inv5tions (1 #g4 ,ar*im$es' pr9ciple1 #f1 #ab4 ,arc light1 #abj4 ,armature1 #aja1 #ajc1 #ajd4 ,balloons1 #agd4 ,b>omet]1 m]cury1 #ai1 #be2 wat]1 #bc4 ,battle ( ,syracuse1 #b4 ,bell1 ,alex&] ,graham1 #ada4 ,blake transmitt]1 #adf4 ,blriot1 #aij4 ,boyle1 #bc4 ,branly1 #bad4 ,cannon exp]im5t1 ,rum=d's1 #ei4 ,cog-:eels1 fir/ us$1 #h4 ,coh]]1 #bad4 ,colors 9 sunlight1 #ca4 ,cond5s] 9 /eam-eng9e1 #dj4 ,conductors1 electrical1 #dd4 ,controll]1 #aaf4 ,daniell cell1 #hi1 #abg4 ,davy1 #ef1 #fa1 #if4 ,de ,=e/1 #bbd4 ,diamonds1 manufactur+1 #bjf4 ,drum armature1 #ajd4 ,dry batt]y1 #ia4 ,du,fay1 #de4 ,dumont1 #agi4 ,duplex telegraphy1 #acf4 ,dynamo1 #ee1 #gi1 #ha1 #if1 #ii1 #ajj1 #aje1 #aaa2 s]ies w\nd1 #aje2 %unt w\nd1 #ajg2 comp\nd w\nd1 #ajh4 ,edison1 #ie1 #aje1 #aad1 #aba4 ,electrical ma*9e1 #bc1 #dd1 #de1 #hc4 ,electric batt]y1 #ec1 #fb1 #hd1 #hi4 ,electric *>ge1 two k9ds1 #de4 ,electric curr5t1 #ej1 #fi1 #gc1 #gd1 #hb1 #if2 magnetic action (1 #ff1 #fh2 produc$ by a magnet1 #gb4 ,electric furnace1 #bje4 ,electricity1 #h1 #ej2 !ories (1 #di2 spe$ (1 #acc4 ,electric light+1 #ig1 #aah4 ,electric motor1 #ga1 #ig1 #aaa4 ,electric p[]1 #aaa4 ,electric railway1 #aab4 ,electric waves1 #bab4 ,electromagnet1 #ajj1 #abf1 #adc4 ,electromagnetism1 #fe4 ,f>aday1 #ee1 #fc1 #ajj1 #aaa2 electrical discov]ies1 #fd4 ,=ce-pump1 #h4 ,frankl91 #dc1 #de1 #df1 #fe4 ,galileo1 #i1 #fc2 exp]im5t ) fall+ %ot1 #ab4 ,galvani1 #ej4 ,galvanomet]1 #gd1 #ge4 ,gas-eng9es1 #aej4 ,glid]1 #ahf4 ,gov]nor1 fly-ball1 #db4 ,gramme-r+ armature1 #ajc4 ,gravitation1 #cj4 ,gravity cell1 #ia4 ,gray1 ,/eph51 #dd4 ,gu]icke1 #bj1 #ce4 ,gyroscope1 #bjj4 ,heat1 #ei4 ,h5ry1 ,joseph1 #ig1 #abg4 ,h]o1 #h1 #afd2 eng9e1 #afd4 ,hi]o1 ,k+ ( ,syracuse1 #a1 #f4 ,horse-p[]1 #dj4 ,hydraulic press1 #bf4 ,inc&esc5t light1 #aba4 ,indicator1 #da4 ,induction-coil1 #gf1 #hb1 #ii4 ,induction1 electrical1 #gd4 ,insulators1 #dd4 ,inv5tions ( ! anci5t ,greeks #g2 ( ! n9ete5? c5tury1 #hh4 ,kite exp]im5t1 ,frankl9's1 #df4 ,kites1 #bg4 ,leyd5 j>1 #dc4 ,lightn+-rod1 #dh4 ,l9es ( =ce1 #ii4 ,liquid air1 #bjc4 ,locomotive1 electric1 #aad2 /eam1 #aee4 ,magdeburg1 #ba4 ,magnetic field1 #hj1 #ii4 ,magnets1 #h1 #acj4 ,m>coni1 #bae4 ,may]1 ,rob]t1 #fa1 #he4 ,m]cury vapor light1 #abe4 ,microscope1 #ah4 ,m9]'s safety lamp1 #fa4 ,monorail c>1 #bja4 ,morse1 #abh4 ,napoleon1 #fb4 ,newcom51 #cd1 #cf4 ,newcom5's eng9e1 #cf4 ,newton1 #bg4 ,niag>a1 #bbg4 ,o]/$1 #fe1 #ga1 #aaa1 #abf4 ,pap91 #ce4 ,pap9's eng9e1 #ce4 ,pascal1 #be4 ,p5dulum clock1 #aj1 #ab4 ,p]petual motion impossible1 #hg4 ,phonograph1 #adg4 ,pr9ciple ( ,"w1 #ai4 ,prism1 #ca4 ,pump1 #h1 #ai4 ,radium1 #bcb4 ,reis1 ,philip1 #ada4 ,relay1 #acj4 ,ro5tg51 #bcb4 ,royal in/itution1 #ef1 #fa4 ,rum=d1 #eg1 #ei4 ,rum=d's cannon exp]im5t1 #ei4 ,safety-lamp1 #fb4 ,screw propell]1 #aga4 ,siem5s1 #ajj4 ,sp9n+ tops1 #aii4 ,/eam-eng9e1 #h1 #be1 #cd4 ,/eam locomotive1 #aee4 ,/eam pressure1 #bc4 ,/eph5son1 #aef4 ,/orage batt]y1 #ic4 ,/urgeon1 #ig1 #abg4 ,subm>9es1 #aij4 ,suction-pump1 #h4 ,symm]1 ,rob]t1 #di4 ,telegraph1 #if1 #abf2 wireless1 #bjh4 ,telephone1 #adj2 wireless1 #bba4 ,telescope1 inv5tion (1 #ae2 ,newton's1 #cb4 ,tesla1 #bca4 ,!rmomet]1 air1 #ac4 ,torp$o1 #aib4 ,torricelli1 #ai1 #ce4 ,trans=m]1 #hj1 #hb1 #ii1 #bbg4 ,turb9e1 #afc4 ,univ]sity ( ,padua1 #ac4 ,univ]sity ( ,pisa1 #aj1 #ab4 ,valve-ge>1 #cg1 #afb4 ,volta1 #ec1 #fc1 #hi4 ,voltaic batt]y1 #ec1 #hi4 ,wat]-clock1 #h1 #bi4 ,wat]-:eel1 #afe4 ,watt1 ,james1 #cd4 ,watt's eng9e1 #ch4 ,wireless telegraph1 #bjh4 ,wright a]oplane1 #ahh4 ,x-rays1 #bcb4 ,zeppel91 #ahj4 ,,! ,,end