,,transcrib]',s ,,notes ,italic text is d5ot$ by und]scores4 ,! oe ligature has be5 exp&$ to 'oe'4 ,subscripts 9 *emical =mulas are d5ot$ by normal numb]s2 = example ,ca,c#b4 ,obvi\s typographical & punctuation errors h be5 correct$ aft] c>eful comp>ison ) o!r occurr5ces )9 ! text & consultation ( ext]nal s\rces4 ,m detail c be f\nd at ! end ( ! book4 ,illu/ration3 ,a ,,primitive ,,use ,,( ,,! ,,animal ,,ma*9e ,,t ,,is ,,/ill ,,9 ,,vogue ,,9 ,,_m ,,european ,,c\ntries4 7,f ! pa9t+ by ,j4 ,didi]1 9 ! ,muse du ,luxemb\rg1 ,p>is47 ,,e-,,day ,,sci5ce ,,by ,,h5ry ,,smi? ,,williams1 ,m4,d41 ,l4,l4,d4 ,,assi/$ ,,by ,,edw>d ,h4 ,,williams1 ,m4,d4 ,,volume ,,vi ,,! ,,conque/ ,,( ,,nature ,,illu/rat$ ,,new ,,york ,,& ,,london ,,! ,,goodhue ,,company ,,publi%]s ,,mdccccix ,copyright1 #aiaj1 by ,,! ,,goodhue ,,co4 ,all rights res]v$ ,,cont5ts ,,*apt] ,i ,,man ,,& ,,nature ,! ,conque/ ( ,nature1 p4 #d--,man's use ( ,nature's gifts1 p4 #f--,man ! tool-mak+ animal1 p4 #g--,sci5ce & ,civilization1 p4 #h--;,clo?+ & artificially heat$ dwell+s ( primitive man1 p4 #aj--;,e>ly dome/ication ( animals1 p4 #aa--;,e>ly developm5t to ! "t ( gunp[d]1 p4 #ab--,! com+ ( /eam & electricity1 p4 #ae--,me*anical aids to ! agriculturi/1 p4 #ai--,! developm5t ( sci5tific agriculture1 p4 #bj--;,difficulties ( ! e>ly manufactur]1 p4 #ba--,! developm5t ( mod]n manufactur+1 p4 #bd--,! relation ( "w to human developm5t1 p4 #be--,! decl9e ( drudg]y & ! new era ( labor-sav+ devices1 p4 #bg4 ,,*apt] ,,ii ,,h[ ,,"w ,,is ,,done ,primitive man's use ( ! lev]1 p4 #bi--,! use ( ! lev] z conceiv$ by ,ar*im$es1 p4 #ba--,:eels & pulleys1 p4 #cb--,o!r means ( transmitt+ p[]1 p4 #ce--;,incl9$ planes & d]ricks1 p4 #cg--,! /eam-scoop1 p4 #ch--;,friction1 p4 #ci--;,available s\rces ( en]gy1 p4 #da4 ,,*apt] ,,iii ,,! ,,animal ,,ma*9e ,! olde/ ma*9e 9 exi/5ce1 p4 #dc--,! relation ( muscle to ma*9]y1 p4 #dd--;,h[ muscul> en]gy is appli$1 p4 #dd--,! two types ( muscles1 p4 #de--;,h[ ! n]ve-telegraph controls ! muscles1 p4 #dg--,! nature ( muscul> action1 p4 #di--;,applications ( muscul> en]gy1 p4 #eb--,! developm5t ( ! knife & saw1 p4 #ec--,! :eel & axle1 p4 #ee--,modifi$ lev]s1 p4 #eg--;,dome/icat$ animals1 p4 #ei--;,e>ly application ( horse-p[]1 p4 #fj--,! horse-p[] z ! /&>d ( ! _w's "w1 p4 #fa4 ,,*apt] ,,iv ,,! ,,"w ,,( ,,air ,,& ,,wat] ,fir/ use ( sails = propell+ boats1 p4 #fb--,! fire eng9e ( ,ctesibius1 p4 #fc--,suction & pressure z /udi$ by ! anci5ts1 p4 #fd--,/udies ( air pressure1 p4 #fe--,! /rik+ demon/ration ( ,von ,gu]icke1 p4 #ff--,! sail+ *>iot ( ,s]v9us1 #afjj ,a4,d41 p4 #fh--,! developm5t ( ! w9dmill1 p4 #fi--,! developm5t ( ! wat]-:eel1 p4 #gj--,! inv5tion ( ! turb9e1 p4 #gb--;,diff]5t types ( turb9es1 p4 #gc--;,hydraulic p[] & its uses1 p4 #gd--,! hydraulic elevator1 p4 #gf--,rec5t wat] motors1 p4 #gg4 ,,*apt] ,v ,,captive ,,molecules3 ,,! ,,/ory ,,( ,,! ,,/eam ,,eng9e ,! developm5t ( ! /eam eng9e1 p4 #gi--,! mann] 9 :i* en]gy is g5]at$ by /eam1 p4 #hj--;,action ( cyl9d] & pi/on1 p4 #ha--;,e>ly attempts to utilize /eam1 p4 #hb--;,beg9n+s ( mod]n discov]y1 p4 #hc--,! eng9e ( ! ,m>quis ( ,worce/]1 p4 #hd--,?omas ,sav]y's /eam pump1 p4 #he--;,d5is ,pap9 inv5ts ! pi/on eng9e1 p4 #hh--,newcom5's improv$ eng9e1 p4 #hi--,! use ( ^! eng9es 9 colli]ies1 p4 #ij--,! wa/efulness ( su* eng9es1 p4 #ib--,! com+ ( ,james ,watt1 p4 #ic--;,e>ly exp]im5ts ( ,watt1 p4 #ie--,! f9al success ( ,watt's exp]im5ts1 p4 #ig--,"s ( 8 e>ly eng9es1 p4 #ih--,rot>y motion1 p4 #ii--,watt's eng9e1 ,old ,bess1 p4 #aja--;,f9al improvem5ts & miss$ opportunities1 p4 #ajb--,! p]sonality ( ,james ,watt1 p4 #ajg4 ,,*apt] ,,vi ,,! ,,ma/] ,,work] ,improvem5ts on ,watt's eng9es1 p4 #aaj--;,eng9es disp5s+ ) ! walk+ beam1 p4 #aaa--,! developm5t ( high-pressure eng9es1 p4 #aab--;,advantages ( ! high-pressure eng9e1 p4 #aad--;,h[ /eam acts 9 ! high-pressure eng9e1 p4 #aaf--;,comp\nd eng9es1 p4 #aag--,rot>y eng9es1 p4 #aai--,turb9e eng9es1 p4 #abd--,! ,turb9ia & o!r turb9e boats1 p4 #abe--,! action ( /eam 9 ! turb9e eng9e1 p4 #abf--;,advantages ( ! turb9e eng9e1 p4 #abg4 ,,*apt] ,,vii ,,gas ,,& ,,oil ,,eng9es ,"s e>ly gas eng9es1 p4 #acc--;,dr4 ,/irl+'s hot-air eng9e1 p4 #acc--;,ericsson's hot-air eng9es1 p4 #acd--,! fir/ practical gas eng9e1 p4 #ace--,! ,otto gas eng9e1 p4 #acf--,otto's improvem5t by means ( compress$ gas1 p4 #ach--,! ,otto cycle1 p4 #aci--;,adaptation ( gas eng9es to automobiles1 p4 #adj--,rapid increase 9 ! use ( gas eng9es1 p4 #ada--;,defects ( ! old] hot-air eng9es1 p4 #ade--,rec5t improvem5ts & possibilities 9 ! use ( hot-air eng9es1 p4 #adf4 ,,*apt] ,,viii ,,! ,,smalle/ ,,work]s ,! relative size ( atoms & electrons1 p4 #adh--,:at is electricity8 p4 #adi--;,frankl9's "o-fluid !ory1 p4 #aej--,mod]n views1 p4 #aec--;,ca?ode rays & ! ,x-ray1 p4 #aef--;,h[ electricity is develop$1 p4 #aei--,! "w ( ! dynamical curr5t1 p4 #afb--,!ories ( electrical action1 p4 #afe--,practical uses ( electricity1 p4 #afh4 ,,*apt] ,,ix ,,man',s ,,newe/ ,,co-,,labor]3 ,,! ,,dynamo ,! me*anism ( ! dynamo1 p4 #agc--,! orig9 ( ! dynamo1 p4 #agf--,! "w ( ,ampre1 ,h5ry1 & ,f>aday1 p4 #agg--,p]fect+ ! dynamo1 p4 #agh--;,a my/]i\s me*anism1 p4 #ahj--;,curi\s relation betwe5 magnetism & electricity z exemplifi$ 9 ! dynamo1 p4 #ahb4 ,,*apt] ,x ,,niag>a ,,9 ,,h>ness ,! volume ( wat] at ! falls1 p4 #ahd--,! po9t at :i* ! falls are h>ness$1 p4 #ahe--,)9 ! p[]-h\se1 p4 #ahf--,p5/ocks & turb9es1 p4 #ahh--;,a miracul\s trans=mation ( en]gy1 p4 #ahi--,subt]ranean tail-races1 p4 #aia--,! effect on ! falls1 p4 #aib--,! transmission ( p[]1 p4 #aid--,/ep-up & /ep-d[n trans=m]s1 p4 #aih4 ,,*apt] ,,xi ,,! ,,bani%m5t ,,( ,,night ,primitive tor* & op5 lamp1 p4 #bjb--,tall[ c&le & p]fect$ lamp1 p4 #bje--;,gas light+1 p4 #bjg--,! inc&esc5t gas mantle1 p4 #bjh--;,e>ly gas mantles1 p4 #bji--;,h[ ! inc&esc5t gas mantle is made1 p4 #baa--,! introduction ( acetyl5e gas1 p4 #bab--;,*emi/ry ( acetyl5e gas1 p4 #bad--,practical gas-mak+1 p4 #bae--,! triumph ( electricity1 p4 #bah--;,davy & ! fir/ electric light1 p4 #bbj--;,helpful discov]ies 9 electricity1 p4 #bbb--,! ,jablo*k(f c&le1 p4 #bbc--;,defects ( ! ,jablo*k(f c&le1 p4 #bbe--,! improv$ arc light1 p4 #bbf--;,edison & ! inc&esc5t lamp1 p4 #bbh--;,difficulties enc\nt]$ 9 f9d+ ! prop] mat]ial = a practical filam5t1 p4 #bcj--,p>*m5tiz$ ?read filam5t1 p4 #bcc--,! tung/5 lamp1 p4 #bcd--,! m]cury-vapor light ( ,pet] ,coop] ,hewitt1 p4 #bcf--;,advantages & peculi>ities ( ?is light1 p4 #bdj4 ,,*apt] ,,xii ,,! ,,m9]al ,,dep?s ,e>ly m9+ me?ods1 p4 #bdb--,prospect+ & locat+ m9es1 p4 #bdc--;,boom+1 p4 #bdf--;,conditions to be consid]$ 9 m9+1 p4 #bdh--;,dang]\s gases 9 m9es1 p4 #bdi--;,artificial lights & light+1 p4 #bea--,v5tilation & dra9age1 p4 #beb--;,electric ma*9]y 9 m9+1 p4 #bec--;,electric drills1 p4 #bed--,traction 9 m9+1 p4 #bef--,v>i\s types ( electric motors1 p4 #beg--,telph]s1 p4 #bfa--;,electric m9+ pumps1 p4 #bfc--,"s rem>kable demon/rations ( durability ( electric pumps1 p4 #bfe--;,electricity 9 coal m9+1 p4 #bff--;,electric light+ 9 m9es1 p4 #bfi4 ,,*apt] ,,xiii ,,! ,,age ,,( ,,/eel ,rapid gr[? ( ! iron indu/ry 9 rec5t ye>s1 p4 #bga--,! ,lake ,sup]ior m9es1 p4 #bgb--,me?ods ( m9+1 p4 #bgc--,op5-pit m9+1 p4 #bgd--,m9+ ) ! /eam %ovel1 p4 #bgf--;,f m9e to furnace1 p4 #bgh--,me?ods ( transportation1 p4 #bgi--,vessels ( special con/ruction1 p4 #bha--,! conv]sion ( iron ore into iron & /eel1 p4 #bhc--;,bla/ furnaces1 p4 #bhd--,poison\s gases & _! effect ^u ! workm51 p4 #bhf--;,f pig iron to /eel1 p4 #bhg--,mod]n me?ods ( produc+ pig iron1 p4 #bhh--,! ,bessem] conv]t]1 p4 #bhi--,sir ,h5ry ,bessem]1 p4 #bia--,! ,bessem]-,mu%et process1 p4 #bic--,op5-he>? me?od1 p4 #bid--;,alloy /eels1 p4 #bie4 ,,*apt] ,,xiv ,,"s ,,rec5t ,,triumphs ,,( ,,appli$ ,,sci5ce ,! prov9ce ( electro-*emi/ry1 p4 #bih--,l9k+ ! laboratory ) ! work%op1 p4 #bii--,soda manufactories at ,niag>a ,falls1 p4 #cjj--,produc+ alum9um by ! electrolytic process1 p4 #cjj--,old & new me?ods comp>$1 p4 #cja--,nitrog5 f ! air1 p4 #cjc--,:at ?is discov]y means to ! food indu/ries ( ! _w1 p4 #cjd--,pr(4 ,birkel&'s me?od1 p4 #cjg--;,ano!r me?od ( nitrog5 fixation1 p4 #cji--;,co/ ( production1 p4 #cab--;,electrical en]gy1 p4 #cac--,production ( high temp]atures ) ! electric arc1 p4 #cad--,! production ( artificial diamonds by ! explosion ( cordite1 p4 #cae--;,indu/rial problems ( to-day & to-morr[1 p4 #caf4 ,,illu/rations ,a ,,primitive ,,use ,,( ,,! ,,animal ,,ma*9e ,,t ,,is ,,/ill ,,9 ,,vogue ,,9 ,,_m ,,european ,,c\ntries ,frontispiece ,,horse ,,& ,,cattle ,,p[] ,fac+ p4 #cb ,,cranes ,,& ,,d]ricks #ch ,a ,,belgian ,,milk-,,wagon #ef ,,two ,,app>atuses ,,= ,,! ,,utilization ,,( ,,animal ,,p[] #fj ,,w9dmills ,,( ,,anci5t ,,& ,,mod]n ,,types #fh ,,wat] ,,:eels #gb ,,hydraulic ,,press ,,& ,,hydraulic ,,cap/an #gf ,,?omas ,,sav]y',s ,,/eam ,,eng9e #hf ,,diagrams ,,( ,,e>ly ,,attempts ,,to ,,utilize ,,! ,,p[] ,,( ,,/eam #hh ,a ,,model ,,( ,,! ,,newcom5 ,,eng9e #ib ,,watt',s ,,e>lie/ ,,type ,,( ,,pump+-,,eng9e #if ,,watt',s ,,rotative ,,eng9e #ajj ,,james ,,watt #ajh ,,old ,,ideas ,,& ,,new ,,appli$ ,,to ,,boil] ,,con/ruction #aad ,,comp\nd ,,eng9es #aah ,,rot>y ,,eng9es #abb ,,! ,,orig9al ,,p>sons' ,,turb9e ,,eng9e ,,& ,,! ,,record-,,break+ ,,%ip ,,= ,,:i* ,,x ,,is ,,responsible #abh ,,gas ,,& ,,oil ,,eng9es #acf ,,an ,,electric ,,tra9 ,,& ,,! ,,dynamo ,,t ,,propels ,,x #agd ,,wilde',s ,,sep>ately ,,excit$ ,,dynamo #agh ,,! ,,evolution ,,( ,,! ,,dynamo #ahj ,,view ,,9 ,,"o ,,( ,,! ,,p[] ,,h\ses ,,at ,,niag>a #ahf ,,electrical ,,trans=m]s #aih ,,?omas ,a4 ,,edison ,,& ,,! ,,dynamo ,,t ,,g5]at$ ,,! ,,fir/ ,,comm]cial ,,inc&esc5t ,,light #bbh ,a ,,fl9t-,,&-,,/eel ,,outfit1 ,,& ,a ,,m9]',s ,,/eel ,,mill #bdh ,,! ,,locomotive ,,puff+ ,,billy ,,& ,a ,,mod]n ,,colli]y ,,trolley #beh ,,! ,,conque/ ,,( ,,nature ,9 ! e>li] volumes we h be5 conc]n$ ) ! gr[? ( k4 ,= ! mo/ "p ! sci5tific delv]s ^: ef=ts h held our att5tion h be5 tacitly unm9dful1 or ev5 explicitly contemptu\s1 ( ! influ5ce ^u practical life ( ! ph5om5a to ! inve/igation ( :i* !y h devot$ _! lives4 ,!y 7 & are obvi\sly seek]s ( tru? = ! m]e love ( tru?4 ,b ! ph5om5a ( nature are n dissociat$ 9 fact1 h[ev] mu* we may attempt to localize & classify !m4 ,& s x *ances t ev5 ! mo/ vision>y devotee ( ab/ract sci5ce is =ev] be+ c>ri$ into fields ( inve/igation tr5*+ closely ^u ! practicalities ( e-day life4 ,a ,black inve/igat+ ! laws ( heat is prep>+ ! way explicitly1 h[ev] unconsci\sly1 = a ,watt ) 8 p]fect$ me*anism ( ! /eam eng9e4 ,simil>ly a ,davy work+ at ! ,royal ,in/itution ) 8 newly inv5t$ batt]ies1 & int5t on ! discov]y ( new elem5ts & ! elucidation ( new pr9ciples1 is ! direct =]unn] ( ,jablo*k(f1 ,bru%1 & ,edison ) _! comm]cial revolution 9 ! production ( artificial light4 ,aga9 ,o]/$ & ,f>aday1 e>ne/ly seek+ out ! fundam5tal facts z to ! relations ( electricity & magnetism1 inv5t me*anisms :i*1 ?\gh !y seem b laboratory toys1 are ! direct =]unn]s ( ! mod]n dynamos t take s l>ge a %>e 9 ! _w's "w4 ,9 a ^w1 all along ! l9e !re is ! close/ association betwe5 :at are commonly call$ ! !oretical sci5ces & :at ) only p>tial propriety are t]m$ ! appli$ sci5ces4 ,! l9kage ( "o ) ! o!r mu/ nev] be =gott5 by anyone :o w\ld truly appreh5d ! /atus ( ^? practical sci5ces :i* h revolutioniz$ ! civilization ( ! n9ete5? & tw5tie? c5turies 9 its mo/ manife/ aspects4 ,nev]!less !re is1 to casual inspection1 a some:at radical di/9ction betwe5 !oretical & practical aspects ( sci5ce--j z !re are obvi\s diff]5ces betwe5 two sides ( a %ield4 ,& z ! !oretical aspects ( sci5ce h l>gely claim$ our att5tion hi!rto1 s its practical aspects w be explicitly put =w>d 9 ! pages t foll[4 ,9 ! pres5t volume we are conc]n$ ) ^? primitive applications ( =ce ?r\gh :i* man e>ly le>n$ to add to 8 work+ effici5cy1 & ) ! elaborate me*anisms--turb9e :eels1 /eam eng9es1 dynamos--?r\gh :i* he has be5 enabl$ to multiply 8 p[]s until x is sc>cely exagg]ation to say t he has made all ,nature subs]vi5t to 8 w4 ,x is ?is view :i* ju/ifies ! title ( ! volume1 :i* might ) equal propriety h be5 t]m$ ! ,/ory ( ! ,_w's ,"w4 ,,! ,,conque/ ,,( ,,nature ,i ,,man ,,& ,,nature ,"y m51 said a wise physician 9 address+ a class ( graduates 9 m$ic9e1 y are ab\t to ent] ! battle ( life4 ,note t ,i say ! 'battle' ( life4 ,n a playgr\nd1 b a battlefield is be=e y4 ,x is a h>d conte/--a battle royal4 ,make no mi/ake z to t4 ,y\r /udies "h h furni%$ y\r equipm5t2 n[ y mu/ g =? ea* to fight = himself4 ,! same words might be said to e neophyte 9 :atev] walk ( life4 ,! pursuit ( e trade1 e pr(ession is a battle--a /ruggle = exi/5ce & = supremacy4 ,p>tly x is a battle aga9/ fell[ m52 p>tly aga9/ ! cont5d+ p[]s ( ,nature4 ,! physician meets rivalry f 8 bro!rs2 b 8 *ief battle is ) disease4 ,9 ! creative & manufactur+ fields :i* w *iefly conc]n u 9 ! foll[+ volumes1 x is ! p[]s ( ,nature t furni% an ev]-pres5t antagonism4 ,no /one c be lift$ above ano!r1 to make ! crude/ wall or dwell+1 b ,nature--repres5t$ by h] p[] ( gravitation--/rives at once to pull x d[n aga94 ,no /ructure is complet$ be=e ! elem5ts are at "w defac+ x1 prep>+ its sl[ b c]ta9 ru94 ,summ] heat & w9t] cold exp& & contract mat]ials ( e k9d2 ra9 & w9d we> & w>p & twi/2 ! oxyg5 ( ! air gnaws into /one & iron alike2--9 a ^w1 all ! elem5ts are at "w undo+ :at man has accompli%$4 ,,! ,,/ruggle ,,= ,,exi/5ce ,9 ! field ( ! agriculturi/ x is ! same /ory4 ,! e>? :i* br+s =? its crop ( un:olesome we$s s b\ntifully1 resi/s man's approa*es :5 he /rives to br+ x "u cultivation4 ,only by ! mo/ c>eful att5tion c useful gra9s be made to gr[ :]e ! wildl+s sw>m$ 9 pr(usion4 ,n only d w9d & ra91 blight+ heat & )]+ cold m5ace ! crops2 b we$s invade ! fields1 ! g]ms ( fungoid pe/s lurk ev]y:]e2 & myriad insects attack or*>d & mead[ & gra9 field 9 deva/at+ legions4 ,simil>ly ! bea/s :i* 7 s rugg$ & resi/ant :ile 9 ! wild /ate1 become t5d] & susceptible to disease :5 made useful by dome/ication4 ,a=etime !y roam$ at l>ge1 brav+ e temp]ature & ?riv+ 9 all wea!rs4 ,b n[ !y mu/ be h\s$ & c>$ = s t5d]ly t !y become1 z ,?oreau said1 ! keep]s ( m51 r ?an kept by m51 s mu* m indep5d5t are !y ?an _! alleg$ own]s4 ,t5d] ( con/itution1 dome/icat$ bea/s mu/ be h\s$1 to protect !m f ! bla/s 9 :i* ( yore _! =ebe>s revell$2 & man mu/ slave day 9 & day out to prep>e food to meet ! requirem5ts ( _! pamp]$ appetites4 ,he mu/ /ruggle1 too1 to protect !m f disease1 & mu/ c>e = !m 9 "t ( illness z s$ul\sly z he c>es = 8 own ki? & k94 ,truly ! ox is keep] ( ! man1 & ! seem+ conque/ t man has wr\ght has co/ him de>4 ,b ( c\rse ! /ory has ano!r side4 ,aft] all1 ,nature is n s malevol5t z at fir/ glance %e seems4 ,%e has oppos$ man at e /age ( 8 attempt$ progress2 yet at ! same "t %e has suppli$ him all 8 weapons = wag+ w> ^u h]4 ,h] great p[] ( gravitation opposes e ef=t he makes2 yet )\t t same p[] he c\ld d no?+--he c\ld n walk or /ay ^u ! e>? ev52 & no /ructure t he builds w\ld hold 9 place = an in/ant4 ,s1 too1 ! w9d t smites him & te>s at 8 h&iwork1 may be made to s]ve ! purposes ( turn+ 8 w9dmills & supply+ him ) p[]4 ,! wat] w s]ve a l purpose 9 turn+ 8 mills2 &1 *ang$ to /eam ) ! aid ( ,nature's /ore ( coal1 w make 8 /eam eng9es & dynamos possible4 ,ev5 ! lightn+ he w h>ness & make subject to 8 w 9 ! telegraphic curr5ts & dynamos4 ,& 9 ! fields1 ! gra9s :i* man /ruggles s ardu\sly to produce are aft] all no ?+ ( 8 creat+4 ,!y are only adopt$ products ( ,nature1 :i* he has /riv5 to make s]ve 8 purpose by gr[+ !m "u artificial conditions4 ,s1 too1 ! dome/icat$ bea/s are creatures t belong 9 ! wilds & 9 di/ant l&s4 ,man has br\ght !m1 9 defiance ( ,nature1 to uncong5ial climes1 & made !m s]ve z work]s & z food-suppli]s :]e ,nature alone c\ld n support !m4 ,turn loose ! c[ & ! horse to =age = !mselves "h 9 ! inhospitable nor?1 & !y w\ld />ve4 ,!y survive because man helps !m to combat ! adv]se conditions impos$ by ,nature1 yet no "o ( !m c\ld live = an h\r 7 n ! vital capacities suppli$ by ,nature /ill 9 control4 ,ev]y:]e1 !n1 x is ! oppos+ ( ,nature1 up to c]ta9 limits1 ) ! aid ( ,nature's own tools1 t con/itutes man's "w 9 ! _w4 ,j 9 proportion z he b5ds ! elem5ts to meet 8 ne$s1 trans=ms ! plants & animals1 defies & exce$s ! limitations ( primeval ,nature--j 9 proportion z he conqu]s ,nature1 9 a ^w1 is he civiliz$4 ,b>b>ic man is call$ a *ild ( ,nature ) full reason4 ,he mu/ accept :at ,nature (f]s4 ,b civiliz$ man is ! *ild gr[n to adult /ature1 & able 9 a mann] to control1 to dom9ate--if y please to conqu]--! p>5t4 ,if we 7 to seek ! means by :i* develop+ man has gradually a*iev$ ?is conque/1 we %\ld f9d x 9 ! s+le ^w1 ,tools2 t is to say1 ma*9es = utiliz+ ! p[]s ( ,nature1 &1 z x 71 multiply+ !m = man's b5efit4 ,s unique is ! capacity t man ex]ts 9 ?is direction1 t he has be5 describ$ z ! tool-mak+ animal4 ,! description is absolutely accurate2 x is inclusive & exclusive4 ,no non-human animal makes any =m ( implem5t to aid x 9 p]=m+ its daily "w2 & contr>iwise e human tribe1 h[ev] l[ its /age ( savag]y1 makes use ( m or less crude =ms ( implem5ts4 ,!re mu/ h be5 a "t1 to be sure1 :5 !re exi/$ a man s l[ 9 intellig5ce t he _h n put into execution ! idea ( mak+ ev5 ! simple/ tool4 ,b ! p]iod :5 su* a man exi/$ s va/ly ant$ates all records t x ne$ n "h conc]n u4 ,= ! purpose ( classify+ all exi/+ m51 & all ! tribes ( m5 ( :i* hi/ory & pre-hi/oric ar*ology give u any record1 ! def9ition ( man z ! tool-mak+ animal is accurate & suffici5t4 ,at fir/ ?\ght x might seem t an equally compreh5sive def9ition might describe man z ! work+ animal4 ,b a mom5t's consid]ation %[s ! fallacy ( su* a sugge/ion4 ,man is1 to be sure1 ! animal t works effectively1 ?anks to ! implem5ts ) :i* he has le>n$ to provide himself2 b he %>es ) all animate creatures ! task ( labor+ = 8 daily necessities4 ,?is is inde$ a "w-a-day _w1 & no creature c live 9 x )\t tak+ its %>e 9 t p]petual conflict :i* bodily necessities make imp]ative4 ,mo/ l[] animals conf9e _! "w to ! m]e secur+ ( food1 & to ! con/ruction ( rude habitations4 ,"s1 inde$1 g a /ep f>!r & lay up /ores ( food1 9 *ance burr[s or holl[ trees2 a few ev5 manufacture relatively arti/ic & highly effective receptacles1 z illu/rat$ by ! honeycomb made by ! bees & _! allies4 ,aga91 c]ta9 animals1 ( :i* ! birds are ! be/ repres5tatives1 con/ruct tempor>y /ructures = ! purpose ( re>+ _! "y t atta9 a relatively high degree ( arti/ic p]fection4 ,! ,baltimore oriole weaves a clo? ( vegetable fibre t is c]ta9ly a wond]ful texture to be made ) ! aid ( claws & bill alone4 ,x may be d\bt$ :e!r human h&s1 unaid$ by implem5ts1 c\ld duplicate x4 ,b x is crude en\gh comp>$ ) ev5 ! co>se/ clo? :i* b>b>ic races manufacture ) ! aid ( implem5ts4 ,s x is ) any comp>ison ( animal "w ) ! "w ( man1 9 :atev] field4 ,! crude/ human endeavor is sup]ior to ! be/ non-human ef=ts2 & ! explanation is f\nd always 9 ! fact t ! +5uity ( man has enabl$ him to f9d artificial aids t add to 8 p[] ( manipulation4 ,s l>ge a %>e h ^! artificial aids tak5 9 man's evolution1 t x has long be5 cu/om>y1 9 /udy+ ! developm5t ( civilization1 to make ! use ( v>i\s types ( implem5ts a te/ ( v>y+ /ages ( human progress4 ,,sci5ce ,,& ,,civilization ,! /ud5t ( primitive life assures u1 bas+ 8 /atem5ts on ! ar*ological records1 t !re 0 a "t :5 ! mo/ advanc$ ( mank9d _h no tools made ( bett] mat]ial ?an *ipp$ /one4 ,by common cons5t t "t is spok5 ( z ! ,r\gh ,/one ,age4 ,we are told t !n 9 ! c\rse ( immeasurable c5turies man le>n$ to poli% 8 /one implem5ts1 d\btless by rubb+ !m aga9/ ano!r /one1 or p]haps ) ! aid ( s&1 ?us produc+ a new type ( implem5t :i* has giv5 its "n to ! ,age ( ,smoo? or ,poli%$ ,/one4 ,!n aft] o!r long c5turies came a "t :5 man _h le>n$ to smelt ! s(t] metals1 & ! new civilization :i* n[ supplant$ ! old1 &1 ?anks to ! new implem5ts1 advanc$ ^u x immeasurably1 is call$ ! ,age ( ,bronze4 ,at la/ man le>n$ to accompli% ! wond]ful feat ( smelt+ ! intractable metal1 iron1 & 9 s do+ produc$ implem5ts h>d]1 %>p]1 & *eap] ?an 8 implem5ts ( bronze2 & :5 ?is cr[n+ feat _h be5 accompli%$1 ! ,age ( ,iron 0 u%]$ 94 ,by common cons5t1 /ud5ts ( ! hi/ory ( ! evolution ( society accept ^! successive ages1 ea* designat$ by ! type ( implem5ts ) :i* ! _w's "w 0 accompli%$1 z repres5t+ real & def9ite /ages ( human progress1 & z ne$+ no bett] def9ition ?an t suppli$ by ! diff]5t types ( implem5ts4 ,c\ld ! ar*ologi/ trace ! /ream ( human progress /ill f>!r back t[>d its s\rce1 he w\ld f9d d\btless t !re 7 sev]al great epo*al inv5tions prec$+ ! "t ( ! ,r\gh ,/one ,age1 ea* ( :i* 0 9 its way z def9itive & z revolution>y 9 its effects ^u society1 z ^! lat] inv5tions :i* we h j nam$4 ,to attempt to def9e !m cle>ly is to ent] ! field ( unc]ta9ty1 b two or ?ree conjectures may be haz>d$ t _c be v wide ( ! tru?4 ,x is cle>1 = example1 t if we g back 9 imag9ation to ! v remote/ ance/ors ( man t c be call$ human1 we mu/ suppose a va/ & revolution>y /age ( progress to h be5 u%]$ 9 by ! fir/ race ( m5 t le>n$ to make habitual use ( ! simple/ implem5t1 su* z a m]e club4 ,:5 man _h le>n$ to wield a club & to ?r[ a /one1 & to use a /one held 9 ! h& to break ! %ell ( a nut1 he _h atta9$ a /age ( culture :i* augur$ great ?+s = ! future4 ,out ( ! idea ( wield$ club & hurl$ /one 7 to gr[ 9 "t ! ideas ( hamm] & axe & spe> & arr[4 ,!n !re came a "t--no "o d>e guess h[ _m ?\s&s ( ye>s lat]--:5 man le>n$ to cov] 8 body ) ! sk9 ( an animal1 & ?us to become 9 a measure fre$ f ! ?raldom ( ! wea!r4 ,he complet$ 8 enfran*isem5t by le>n+ to avail himself ( ! heat provid$ by an artificial fire4 ,equipp$ ) ^! two m>vel\s inv5tions he 0 able to ext5d ! hi!rto n>r[ b\nds ( 8 dwell+-place1 pass+ nor?w>d to ! regions :i* at an e>li] /age ( 8 developm5t he d>$ n p5etrate4 ,"u /ress ( m exhil>at+ climatic conditions1 he develop$ new ideals & le>n$ to ov]come new difficulties2 develop+ bo? a mat]ial civilization & ! advanc$ m5tality t is its c\nt]p>t1 z he d\btless nev] w\ld h done _h he rema9$ subject to ! m pamp]+ conditions ( ! tropics4 ,! mo/ important1 p]haps1 ( ! new ?+s :i* he 0 taught by ! seem+ly adv]se conditions ( an inhospitable climate1 0 to provide = ! ne$s ( a w&]+ life & ( v>y+ seasons by dome/icat+ animals t c\ld af=d him an ev]-pres5t food supply4 ,9 s do+ he ceas$ to be a m]e fi%] & hunt]1 & became a h]dsman4 ,"o o!r /ep1 & he _h conceiv$ ! idea ( provid+ = himself a supply ( vegetable foods1 to take ! place ( t :i* nature _h provid$ s b\ntifully 9 8 old home 9 ! tropics4 ,:5 ?is idea 0 put into execution man became an agriculturi/1 & _h ent]$ ^u ! high road to civilization4 ,all ^! /ages ( progress _h be5 ent]$ ^u prior to ! "t ( :i* ! olde/ kn[n rema9s ( ! cave-dwell] give u k4 ,x 7 idle to conjecture ! precise sequ5ce 9 :i* ^! e>lie/ /eps t[>d civilization 7 tak51 & ev5 m idle to conjecture ! l5g? ( "t :i* elaps$ betwe5 "o /ep & its successor4 ,b all que/ions ( precise sequ5ce aside1 x is cle> t "h 7 f\r or five great ages succe$+ "o to ano!r1 t m>k$ ! onw>d & upw>d progress ( our primeval ance/or be=e he a*iev$ ! /age ( developm5t t enabl$ him to leave p]man5t records ( 8 exi/5ce4 ,&--:at is p>ticul>ly significant f our pres5t /&po9t--x is equally cle> t ea* ( ! great ages ?us vaguely outl9$ 0 dep5d5t ^u an a*ievem5t or an inv5tion t facilitat$ ! c>ry+ out ( t s*eme ( nev]-end+ "w :i* f fir/ to la/ has be5 man's portion4 ,h[ to labor m effici5tly1 m productively2 h[ to produce m ( ! necess>ies & ( ! luxuries t man's physical & m5tal be+ dem&s1 ) less exp5diture ( toil--t f fir/ to la/ has be5 ! ev]-insi/5t problem4 ,& ! answ] has be5 f\nd always ?r\gh ! developm5t ( "s new species ( me*anism1 "s new labor-sav+ device1 "s +5i\s manipulation ( ! p[]s ( ,nature4 ,if1 turn+ f ! hypo!tical p]iod ( our primitive ance/or1 we consid] ! sweep ( secure & relatively rec5t hi/ory1 we %all f9d t precisely ! same ?+ holds4 ,if we contra/ ! civilization ( ,old ,egypt & ,babylonia--! olde/ civilizations ( :i* we h any secure record--) ! civilization ( to-day1 we %all f9d t ! diff]5ces betwe5 ! "o & ! o!r are su* z are due to new & improv$ me?ods ( accompli%+ ! _w's "w4 ,inde$1 if we view ! subject c>efully1 x w become m & m evid5t t ! only real progress t ! hi/oric p]iod has to %[ is su* z has gr[n directly f ! developm5t ( new me*anical inv5tions4 ,! m we /udy ! anci5t civilizations ! m we %all be /ruck ) _! m>vel\s resemblance1 z reg>ds m5tal life1 to ! civilization ( to-day4 ,9 _! moral & spiritual ideals1 ! anci5t ,egyptians 7 z bro!rs to ! mod]n ,europeans4 ,9 philosophy1 9 art1 9 lit]ature1 ! ,age ( ,p]icles e/abli%$ /&>ds t /ill rema9 unexcell$4 ,9 all ! subtleties ( ?\ght1 we feel t ! ,greeks _h rea*$ intellectual b\nds t we h n be5 able to ext5d4 ,b :51 on ! o!r h&1 we consid] ! mat]ial civilization ( ! two epo*s1 we f9d contra/s t are altoge!r />tl+4 ,! little _w ( ! ,greeks ne/l$ ab\t ! ,m$it]ranean1 b\nd$ on e side at a di/ance ( a few hundr$ leagues by a t]ra incognita4 ,! philosoph]s :o _h rea*$ ! conf9es ( ! field ( ?\ght1 _h b ! n>r[e/ k ( ! geography ( our globe4 ,!y trav]s$ at be/ a few petty miles ( its surface on foot or 9 c>ts2 & !y navigat$ ! ,m$it]ranean ,sea1 or at mo/ coa/$ out a little way beyond ! ,pill>s ( ,h]cules 9 boats *iefly propell$ by o>s4 ,by d9t ( great indu/ry !y produc$ a really a/oni%+ numb] ( books1 b ! production ( ea* "o 0 a long & labori\s task1 & ! aggregate numb] indit$ dur+ ! ,age ( ,p]icles 9 all ! _w 0 p]haps n great] ?an an aft]noon's output ( a mod]n pr9t+ press4 ,9 a ^w1 ^! m5 ( ! classical p]iod ( antiquity1 great z 7 _! m5tal1 arti/ic1 & moral a*ievem5ts1 7 z *ildr5 9 ^? matt]s ( practical me*anics ^u :i* ! outw>d evid5ces ( civilization dep5d4 ,%\ld we f9d a race ( p to-day 9 "s hi!rto unexplor$ portion ( ! e>?--did su* unexplor$ portions /ill exi/--liv+ a life comp>able to t ( ! ,age ( ,p]icles1 we %\ld m>vel no d\bt at _! arti/ic a*ievem5ts1 :ile at ! same "t reg>d+ !m z sc>cely bett] ?an b>b>ians4 ,inde$ ?is is m ?an unsupport$ hypo!sis2 = has x n be5 difficult = ! ,we/]n _w to admit ! truly civiliz$ condition ( ! ,*9ese1 simply because t highly intellectual race ( ,ori5tals has n kept abrea/ ( ! ,occid5tal *anges 9 appli$ me*anics8 ,say :at we w1 ?is is ! /&>d :i* we ( ! ,we/]n _w apply z ! te/ ( civilization4 ,if1 sweep+ ov] 9 retrospect ! hi/ory ( ! _w s9ce ! "t :5 ! ,egyptian & ,babylonian civilizations 7 at _! height1 we attempt "s su* classification ( ! /ages ( progress z t :i* we a mom5t ago appli$ to pre-hi/oric times1 we %all be l$ to "s r />tl+ conclusions4 ,9 ! broade/ view1 x w appe> t ! age :i* u%]$ 9 ! hi/oric p]iod cont9u$ unbrok5 by ! advance ( any great revolution>y inv5tion ?r\gh\t ! long c5turies ( pre-,*ri/ian antiquity1 & well into ! s-call$ ,middle ,ages ( our new] era4 ,!n came ! inv5tion ( gunp[d]1 or at lea/ its introduction to ! ,we/]n _w--s9ce ! ,*9aman "h lays claim to vague c5turies ( prec$5ce4 ,foll[+ h>d ^u ! introduction ( gunp[d]1 ) its capacity to add to ! de/ructive effici5cy ( man's mo/ s9i/] =m ( labor1 came a me*anism no less epo*-mak+ 9 a f> diff]5t field--! pr9t+ press4 ,b ev5 ^! inv5tions1 great z 0 _! influ5ce ^u ! progress ( civilization1 c sc>cely be consid]$1 x seems to me1 z tak+ rank ) ! great epo*al discov]ies t gave _! names to ! prec$+ ages4 ,nor c any inv5tion ( ! sixte5? or sev5te5? c5tury be hail$ z really u%]+ 9 a new era4 ,! inv5tion = :i* t honor 0 res]v$ 0 a developm5t ( ! eighte5? c5tury2 & did n come fully to its h]itage until ! e>ly days ( ! n9ete5? c5tury4 ,! inv5tion 0 ! application ( /eam to ! purposes ( me*anics4 ,:5 ?is application 0 made1 z wide a gap 0 cross$ z t :i* sep>at$ ! ,/one ,age f ! ,age ( ,metal2 !n ! epo* 9 :i* ! _w 0 liv+ :5 hi/ory beg9s 0 br\ght to a close1 & a new era1 ! ,age ( ,/eam1 0 u%]$ 94 ,sc>cely _h ! _w begun to adju/ itself to ! new conditions ( ! ,age ( ,/eam1 :5 yet ano!r p[] 0 made subs]vi5t to man's ne$s1 & ! ,age ( ,/eam 0 supplem5t$1 n to say supplant$1 by ! ,age ( ,electricity4 ,( c\rse ! new progressive movem5ts did n necess>ily imply elim9ation ( old conditions2 !y imply m]ely ! subord9ation ( old p[]s to new] & bett] ones4 ,/one implem5ts by no means ceas$ to h utility at once :5 metal implem5ts came into vogue4 ,bronze long held its own aga9/ iron1 & /ill has its utility4 ,& iron itself f9ds b an add$ sph]e ( usefulness 9 ! ,age ( ,/eam & ,electricity4 ,all great *anges are relatively sl[4 ,x is only z we look back ^u !m & view !m 9 p]spective t !y seem cataclysmic4 ,gunp[d] did n at once supplant ! crossb[1 & ! cannon 0 long held to be inf]ior to ! catapult4 ,! pr9t$ book did n in/antly make its way aga9/ ! "w ( ! scribe4 ,nei!r did ! /eam eng9e imm$iately supplant wat] p[] & ! direct application ( human labor4 ,b 9 ea* case ! new inv5tion virtually rang ! dea? knell ( ! old me?od f ! h\r ( its inauguration1 & ! end 0 no less sure because x 0 delay$4 ,& x requires no great p[]s ( div9ation to =etell t 9 ! com+ age1 ! electric dynamo driv5 by wat] p[] may take ! place ( ! /eam eng9e4 ,! ,age ( ,/eam may pass1 ) only at mo/ a few g5]ations ( dom9ation4 ,& x is )9 ! possibilities t ! ,age ( ,electricity w sc>cely come into its own be=e x may be displac$ by an ,age ( ,radio-,activity4 ,to press t po9t1 h[ev]1 w\ld be to ent] ! field ( prophecy1 :i* is no "p ( my pres5t purpose4 ,all t ,i h wi%$ to po9t out is t = "s ?\s&s ( ye>s aft] man le>n$ to make implem5ts ( iron1 ! indu/rial _w & ! human civilization t dep5ds ^u x1 pursu$ a relatively /atic c\rse1 l a broad1 sluggi% curr5t1 ) no new revolution>y discov]y to impel x into new *annels2 & t !n "o revolution>y discov]y succe$$ ano!r ) bewild]+ sudd5ness1 s t we ( ! e>ly days ( ! tw5tie? c5tury are f>!r remov$1 9 an indu/rial way1 f our =]unn]s ( two hundr$ ye>s ago1 ?an ^? *ildr5 ( ! eighte5? c5tury 7 f ! e>lie/ civilization t ev] develop$ on our globe4 ,inde$1 ?is />tl+ contra/ w\ld /ill hold true1 7 we to consid] ! newe/ era z compass+ only ! p]iod ( a s+le life4 ,!re are m5 liv+ to-day :o 7 born 9 t epo* :5 ! /eam eng9e 0 = ! fir/ "t us$ to turn ! :eels ( factories4 ,!re are _m m5 :o c well rememb] ! fir/ practical application ( /eam to railway traffic4 ,ho/s ( m5 c rememb] :5 ! fir/ comm]cial message 0 transmitt$ by electricity along a wire4 ,ev5 middle-ag$ m5 recall ! fir/ cable message t l9k$ ! old _w ) ! new4 ,& ! application ( ! dynamo to ! purposes ( ! _w's "w is an affair ( b ye/]day4 ,! hi/orian ( ! future1 ca/+ 8 eye back across ! long p]spective ( hi/ory1 w f9d civiliz$ man pursu+ an ev5 & unbrok5 c\rse across ! ages f ! "t ( ! pyramids ( ,egypt to ab\t ! "t ( ! ,fr5* ,revolution4 ,!re w be no de>? ( incid5t to claim 8 att5tion 9 ! way ( w>s & conque/s1 & *ang+ cre$s1 & ! rise & fall ( nations1 ea* pursu+ virtually ! same c\rse ( gr[? & decay z all ! o!rs4 ,b :5 he comes to ! close ( ! eighte5? c5tury1 x w n be ! social p>oxysm ( a nation1 or ! meteoric c>e] ( a ,napoleon t w claim 8 att5tion s mu* z ! introduction ( t new me?od ( utiliz+ ! p[]s ( ,nature :i* f\nd its expression 9 ! me*anism call$ ! /eam eng9e4 ,if ! "n ( any individual /&s out z ! great & memorable "o ( t epo* ( transition1 at :i* ! /atic curr5t ( previ\s civilization *ang$ sudd5ly to a ,niag>a-curr5t ( progress1 x w be ! "n ( ! great sci5tific inv5tor1 r ?an t ( ! great milit>y conqu]or--! "n ( ,james ,watt1 r ?an t ( ,napoleon4 ,! milit>y conqu]or _h 8 day ( surpass+ glory & dep>t$1 to leave ! _w only a little worse ?an he f\nd x4 ,b ! me*anical inv5tor left a h]itage t 0 to add day by day to ! weal? & happ9ess ( humanity1 supply+ millions ( artificial h&s1 & mak+ possible su* b5efic5t improvem5ts z no previ\s age _h dream$ (4 ,tasks t human h&s _h p]=m$ sl[ly1 labori\sly1 & inadequately1 7 n[ to be p]=m$ swiftly1 ) ease1 & well by ! artificial h&s provid$ ) ! aid ( ! new p[]4 ,:]e c>ts drawn by horses _h toil$ sl[ly across ! l&1 & %ips driv5 by ! w9d _h drift$ sl[ly ?r\gh ! wat]s1 massive tra9s ( c>s 7 to hurtle to ! f\r corn]s ( ! e>? ) inconceivable spe$1 & float+ palaces 7 to c\rse ! wat]s ) almo/ equal defiance to ! limitations ( "t & space4 ,& !n !re came t /ill weird] conque/ ( "t & space1 wr\ght by ! electric curr5t4 ,! mom5t :5 man fir/ spoke ) man f cont95t to cont95t 9 defiance ( ! oceans1 m>k$ ! dawn+ ( t l>g] day :5 all mank9d %all con/itute "o bro!rhood & all peoples b a s+le nation4 ,)9 a half c5tury ! sun ( t new day has ris5 well above ! horizon1 & f> soon] ?an ev5 ! optimi/ ( to-day d>e pr$ict ) c]ta9ty1 x seems de/9$ to rea* its z5i?4 ,b "h aga9 we v]ge ^u ! dang]\s field ( prophecy4 ,let u turn f x & ca/ an eye back across ! mo/ wond]ful ( c5turies1 contra/+ ! conditions ( to-day 9 ea* ( a half-doz5 fields ( ! _w's "w1 ) ! conditions t obta9$ at ! close ( ! eighte5? c5tury4 ,su* a brief survey w %[ u p]haps m vividly ?an we c\ld o!rwise be %[n1 h[ va/ has be5 ! progress1 h[ m>vel\s ! developm5t ( civilization1 9 ! %ort decades t h elaps$ s9ce ! com+ ( ! ,age ( ,/eam4 ,let u pay he$ fir/ to ! _w ( ! agriculturi/4 ,c\ld we turn back to ! days ( our gr&p>5ts1 we %\ld f9d f>m+ a v diff]5t employm5t f :at x is to-day4 ,= ! mo/ "p ! f>m] op]at$ b a few small fields2 if he _h ?irty or =ty acres ( pl\gh$ l&1 he f\nd ample employm5t = 8 capacities4 ,he pl\gh$ 8 fields ) ! aid ( ei!r a yoke ( ox5 or a team ( horses2 he s[$ 8 gra9 by h&2 he cultivat$ 8 corn ) a hoe2 he reap$ 8 oats & :eat ) a cradle--a device b "o /ep remov$ f a sickle2 he ?re%$ 8 gra9 ) a flail2 he gr\nd su* portion ( x z he ne$$ = 8 own use ) ! aid ( wat] p[] at a neighbor+ mill2 & su* portion ( x z he sold 0 transport$ to m>ket1 be x f> or ne>1 9 wagons t compass$ tw5ty or ?irty miles a day at be/4 ,z reg>ds live /ock1 ea* f>m] rais$ a few cattle1 %eep1 & hogs1 & but*]$ !m to supply 8 own ne$s1 sell+ ! residue to a local deal] :o suppli$ ! non-agricultural portion ( ! neighborhood4 ,any live /ock int5d$ = a di/ant m>ket 0 driv5 on foot across ! c\ntry to its de/9ation4 ,ea* t[n & city1 !re=e1 drew almo/ exclusively = its supply f ! imm$iately surr\nd+ c\ntry4 ,to-day ! small f>m] has become almo/ obsolete1 & ! f>ms ( ! ea/]n /ates t 7 ! nation's *ief s\rce ( supply a c5tury ago are l>gely all[$ to lie fall[1 x be+ no long] possible to cultivate !m pr(itably 9 competition ) ! ri* f>m l&s ( ! middle we/4 ,9 t new home ( agriculture1 ! f>m t does n comprise two or ?ree hundr$ acres is consid]$ small2 & l>ge f>ms are ^? t numb] _! acres by ?\s&s4 ,! soil is turn$ by /eam pl\ghs2 ! gra9 is s[n ) me*anical se$]s & plant]s2 ! corn is cultivat$ ) a horse-drawn ma*9e1 hav+ blades t d ! "w ( a doz5 m52 h>ve/]s drawn by ?ree or f\r horses sweep ov] ! fields & leave ! gra9 me*anically ti$ 9 bundles2 ! /eam ?re%] places ! gra9 9 sacks by hundr$s ( bu%els a day2 & ?is gra9 is hurri$ (f 9 /eam c>s to di/ant mills & yet m di/ant m>kets4 ,meantime ! rais+ ( live /ock has become a special dep>tm5t1 ) :i* ! f>m] :o deals 9 c]eals (t5 has no conc]n4 ,! cattle roam ov] va/ pa/ures & are h]d$ 9 ! w9t] = fatt5+ 9 great droves1 & protect$ f ! cold 9 b>ns t1 :5 contra/$ ) ! %$s ( ! old-"t f>m]1 seem almo/ palatial4 ,:5 9 m>ketable condition1 cattle are no long] slaught]$ at ! f>m1 b are transport$ 9 c>s to "o ( ! few great c5tres1 *ief ( :i* are ! /ock y>ds ( ,*icago & ( ,kansas ,city4 ,at ^! c5tres1 slaught] h\ses & meat-pack+ h\ses ( /up5d\s magnitude h be5 develop$1 capable ( h&l+ millions ( animals 9 a ye>4 ,f ^! c5tres ! meat is transport$ 9 refrig]ator c>s to ! seabo>ds1 & 9 refrig]ator %ips to all p>ts ( ! _w4 ,beef t grew on ! ranges ( ! f> we/ may ?us be (f]$ = sale 9 ! m>kets ( ,new ,engl& villages1 at a price t prohibits local competition4 ,a m radical metamorphosis 9 agricultural conditions ?an all ?is implies c\ld n well be conceiv$4 ,& :5 we recall once m t ! agricultural conditions t obta9$ at ! beg9n+ ( ! n9ete5? c5tury 7 closely simil> to ^? t obta9$ 9 ea* successive age = a hundr$ prec$+ c5turies1 we %all ga9 a vivid idea ( ! revolutioniz+ effects ( new me?ods ( "w 9 ! mo/ important ( indu/ries4 ,x is little wond] t 9 ?is %ort "t ! _w has n solv$ to ! satisfaction ( ! economi/s all ! new problems ?us s sudd5ly develop$4 ,turn n[ to ! manufactur+ _w4 ,9 ! days ( our great-gr&p>5ts almo/ e h\sehold 0 a m9iature factory :]e cotton & wool 7 spun & ! products 7 wov5 into clo?4 ,x 0 n till t[>d ! close ( ! eighte5? c5tury--j at ! "t :5 ,watt 0 p]fect+ ! /eam eng9e--t ,arkwright develop$ ! sp9n+-frame1 & 8 successors elaborat$ ! ma*9]y t made possible ! manufacture ( clo? 9 :olesale quantities2 & ! n9ete5? c5tury 0 well "u way be=e ! h\sehold production ( clo? _h be5 entirely supplant$ by factory production4 ,x is no?+ less ?an pitiful to contemplate 9 imag9ation our great-great-gr&mo!rs--& all _! =ebe>s ( ! long c5turies--drudg+ away day aft] day1 ye> 9 & ye> out1 at ! ceaseless task ( sp9n+ & weav+--only to produce1 z ! output ( a lifetime ( labor1 a quantity ( clo? equival5t p]haps to :at our p]fect$ ma*9e1 driv5 by /eam1 & manipulat$ by a factory girl1 produces ea* work+ h\r ( e day4 ,simil>ly1 c>pets & quilts 7 ( home manufacture2 s 7 coats & dresses2 & %oes 7 at mo/ ! product ( ! local %oemak] ar\nd ! corn]4 ,9 ! kit*51 food 0 cook$ ov] ! coals ( a great fireplace or 9 ! brick ov5 connect$ ) t fireplace4 ,meat 0 suppli$ f a neighbor+ f>m2 eggs 7 ! product ( ! h\sewife's own p\ltry y>d2 ! son or daught] ( ! f>m] milk$ ! c[ & drove h] to & f ! pa/ure2 ! milk 0 set 9 pans 9 ! cell>--on a sw++ %elf1 pref]ably1 to make x inaccessible to ! rats2 & twice a week ! cream 0 made into butt] 9 a primitive *urn1 ! da%] ( :i* 0 op]at$ by ! vigor\s arm ( ! h\sewife h]self1 or by ! unwill+ arms ( "s "o ( h] num]\s prog5y4 ,to give v>iety to ! diet>y1 fruits gr[n 9 ! local g>d5 or or*>d 7 pres]v$1 ea* 9 its season1 by ! indu/ri\s h\sewife1 & /or$ away 9 ! capaci\s cell>2 :]e also might be f\nd ! supply ( home-gr[n potatoes1 turnips1 c>rots1 p>snips1 & cabbages to provide = ! ne$s ( ! w9t]4 ,fuel to supply ! h\sehold ne$s1 bo? = cook+ & heat+1 0 cut 9 ! neighbor+ woodl&1 & c>efully cord$ 9 ! door-y>d1 :]e x provid$ mo/ uncong5ial employm5t = ! y\? ( ! family aft] s*ool h\rs & ( a ,saturday aft]noon4 ,! a%es produc$ :5 ?is wood 0 burn$ 9 ! v>i\s fireplaces1 7 n wa/$1 b 7 c>efully deposit$ 9 b>rels1 f :i* 9 due c\rse lye 0 extract$ by ! simple process ( p\r+ wat] ov] ! cont5ts ( ! b>rel4 ,meantime scraps ( fat f ! table 7 collect$ ?r\gh\t ! w9t] & pres]v$ ) equal c>e2 & 9 due c\rse on "s leisure day 9 ! spr+time--heav5 kn[s h[ a leisure day 0 ev] f\nd 9 su* a s*eme ( dome/ic economy6--! lye drawn f ! a%-b>rels & ! scraps ( fat 7 put into a gigantic kettle1 und]nea? :i* a fire 0 k9dl$2 ) ! result t ultimately a supply ( s(t soap 0 provid$ ! h\sewife1 ) :i* h] entire e/abli%m5t1 prog5y includ$1 c\ld be kept 9 a /ate ( relative cleanness4 ,! read] ( ^! pages has b to ca/ 8 eye ab\t him 9 ! h\sehold 9 :i* he lives1 & contra/ ! conditions j depict$ ) ^? ( 8 e-day life1 to realize :at *ange has come ov] ! aspects ( h\sehold economy 9 ! c\rse ( a %ort c5tury4 ,nor ne$ he be told 9 ea* ( ! v>i\s dep>tm5ts ( :i* ! activities are "h outl9$1 t ! *anges :i* he obs]ves h be5 due to ! application ( ma*9]y 9 all ! ess5tial l9es ( "w 9 "q4 ,we ne$ n pause to detail ! multitud9\s devices = ! economy ( h\sehold labor :i* owe _! orig9 to ! same ag5cy4 ,!re /ill rema9s1 to be sure1 en\gh ( drudg]y 9 ! task ( ! h\sewife2 yet h] mo/ /r5u\s day seems a m]e playtime 9 comp>ison ) ! av]age day ( h] mat]nal =ebe> ( ?ree or f\r g5]ations ago4 ,b we mu/ n "h pause = fur!r outl9es ( a subject :i* x is ! purpose ( ?is & succe$+ volumes to explicate 9 detail4 ,all our succe$+ *apt]s w b make x m cle> h[ m>vel\s are ! elaborations ( me?od & ( me*anism ?r\gh :i* ! _w's "w ( to-day is accompli%$4 ,we %all consid] fir/ ! me*anical pr9ciples t und]lie "w 9 g5]al1 pass+ on to "s ( ! pr9cipal me?ods ( application ?r\gh :i* ! p[]s ( ,nature are made available4 ,we %all !n take up 9 succession ! diff]5t fields ( indu/ry4 ,we %all ask h[ ! "w ( ! agriculturi/ is done 9 ! mod]n _w2 h[ ! multitud9\s l9es ( manufacture are c>ri$ out2 h[ transportation is effect$2 we %all exam9e ! modus op]&i ( ! transmission ( ideas2 we %all ev5 consid] t de/ructive =m ( labor :i* manife/s itself 9 ! production ( me*anisms ( w>f>e4 ,z we foll[ out ! /ories ( ! all-ess5tial indu/ries we %all be l$ to realize m fully p]haps ?an we h done be=e1 ! mean+ ( "w 9 its relations to human developm5t2 & 9 p>ticul> ! mean+ ( mod]n "w1 z c>ri$ out ) ! aid ( mod]n me*anical contrivances1 9 its relations to mod]n civilization4 ,! full =ce ( ^! relations may be/ be p]mitt$ to unfold itself z ! /ory proce$s4 ,!re is1 h[ev]1 "o fundam5tal pr9ciple :i* ,i w\ld ask ! read] to be> con/antly 9 m9d1 z an aid to ! full appreciation ( ! importance ( our subject4 ,x is t 9 consid]+ ! output ( ! work] we h con/antly to d ) "o =m or ano!r ( prop]ty1 & t prop]ty is ! v f\ndation-/one ( civilization4 ,x is impossible1 says ,morgan1 9 8 "w on ,anci5t ,society1 to ov]e/imate ! influ5ce ( prop]ty 9 ! civilization ( mank9d4 ,x 0 ! p[] t br\ght ! ,aryan & ,semitic nations out ( b>b>ism into civilization4 ,! gr[? ( ! idea ( prop]ty 9 ! human m9d comm5c$ 9 feebl5ess & end$ 9 becom+ its ma/] passion4 ,gov]nm5ts & laws are in/itut$ ) prim>y ref]5ce to its creation1 protection1 & enjoym5t4 ,x introduc$ human slav]y 9 its production2 &1 aft] ! exp]i5ce ( sev]al ?\s& ye>s1 x caus$ ! abolition ( slav]y ^u ! discov]y t ! freeman 0 a bett] prop]ty-mak+ ma*9e4 ,if1 !n1 we recall t )\t labor !re is no prop]ty1 we %all be 9 an attitude ( m9d to appreciate ! importance ( our subject2 we %all realize1 some:at beyond ! b\nds ( its m tangible & sordid relations1 ! ess5tial dignity1 ! fundam5tal importance--9 a ^w1 ! true mean+--( ,"w4 ,und\bt$ly !re is a mod]n t5d5cy to accept ?is view ( ! dignity ( physical labor4 ,at any rate1 we diff] f ! savage 9 ?9k+ x m fitt+ t man %\ld toil ?an t 8 wife %\ld labor to support him--?\gh x _c be d5i$ t ev5 n[ ! numb] ( physical toil]s among wom5 greatly exce$s ! numb] ( su* toil]s among m54 ,b 9 :atev] measure we admit ?is attitude ( m9d1 !re c be no "q t x is exclusively a mod]n attitude4 ,"t out ( m9d1 physical labor has be5 di/a/eful to mank9d1 & x is a lat] developm5t ( philosophy t appreciates ! b5efic5ce ( ! task s little reli%$4 ,! b>b>ian =ces 8 wife to d mo/ ( ! "w1 & glories 9 8 own fre$om4 ,e>ly civilization kept conqu]$ foes 9 ?raldom1 develop+ an h]$it>y body ( slaves1 ^: function x 0 to d ! physical "w4 ,! ,hebrew expla9$ ! necessity = labor z a curse impos$ ^u ,fa!r ,adam & ,"m ,eve4 ,plato & ,ari/otle1 voic+ ! _s ( ! ,greeks1 consid]$ manual toil z degrad+4 ,to-day we he> mu* ( ! dignity ( labor2 b if we w\ld avoid cant we mu/ admit t n[--sc>cely less ?an 9 all ! old5 days--! physical toil] is su* because he _c help himself4 ,few inde$ are ! manual labor]s :o "k any o!r means ( gett+ _! daily bread ?an t :i* !y employ4 ,! mo/ /r5u\s advocates ( ! /r5u\s life are n !mselves till]s ( ! soil or work]s 9 factories or ma*9e %ops4 ,! f>m y\? ( intellig5ce does n rema9 a f>m]2 he goes to ! city1 & we f9d him pres5tly at ! head ( a railroad or a bank1 or practis+ law or m$ic9e4 ,! m intellig5t labor] becomes f9ally a =eman1 & no long] h&les ! axe or sl$ge4 ,we %\ld ?9k x grotesque 7 we to see a man ( intellectual p[] ob/9ately foll[+ a pursuit t co/ him habitual physical toil4 ,:5 n[ & !n a ,tol/oi (f]s an exception to ?is rule1 we feel t he is at lea/ ecc5tric2 & we may be excus$ ! d\bt :e!r he w\ld foll[ ! manual task *e]fully if he did n "k t he c\ld at any mom5t ab&on x4 ,x is because he kn[s t ! _w und]/&s him to be only a dilettante t he rejoices 9 8 task4 ,aft] all1 !n1 judg$ by ! mod]n practice1 r ?an by ! philosoph]'s precept1 ! old ,hebrew & ,greek ideas 7 n s f> wrong4 ,us+ ! poetical language :i* 0 s native to !m1 x might be said t ! necessity = physical labor is a curse--a disgrace4 ,a p>tial explanation ( ?is may be f\nd 9 ! fact t ! mo/ uncong5ial tasks are also ! wor/ paid1 :ile ! cong5ial tasks comm& ! high emolum5ts4 ,g5]ally speak+ !re is no di/9ction betwe5 "o labor] & ano!r 9 ! same field--except :]e ! em95tly fair me?od ( piece "w c be employ$4 ,ev5 ! skill$ labor] is usually paid by ! day1 & ! am\nt he is to receive is commonly fix$ by a ,union reg>dless ( 8 effici5cy z comp>$ ) o!r labor]s ( ! same class4 ,& !re is no possibility ( 8 receiv+ any su* sums z ! man :o plans ! "w1 b does no?+ ) 8 own h&s4 ,x has always be5 s4 ,j z ^? :o ?9k mu/ gov]n ^? t toil1 s ! ?9k] mu/ comm& ! high rew>d4 ,p>tly ?is is because man1 consid]$ z a m]e toil]1 is s relatively ineffici5t a work]4 ,:5 he /rives to "w ) 8 h&s1 8 ef=t is b a pitiful "o2 he c by no possibility compete 7z reg>ds m]e quantity ( labor7 ) ! ox & ! horse4 ,he is impati5t ( 8 own pu]ile ef=ts4 ,x is only :5 he br+s ! products ( +5uity to 8 aid t he is able to %[ 8 sup]iority1 & to ju/ify 8 own egotism4 ,s x is t 9 e age he has /riv5 to f9d means ( add+ to 8 feeble p[]s ( body ?r\gh ! use ( 8 relatively gigantic p[]s ( m9d4 ,& 9 proportion z he ?us is able to make 8 head "w = 8 h&s z ! say+ goes1 he v]ges t[>d ! heights ( civilization4 ,to accompli% ?is m & m fully has ev] be5 ! task ( sci5ce z appli$ to ! indu/ries4 ,x w be our object 9 ! ensu+ *apt]s to inquire h[ f> sci5ce has accompli%$ ! protean task ?us set = x4 ,we %all see t mu* has be5 done2 b t mu* /ill rema9s to be done4 ,9 proportion z ! problems are unsolv$1 sci5ce is reproa*$ = its %ortcom+s--& /imulat$ to new ef=ts4 ,9 proportion z labor has be5 m9imiz$ & production increas$--9 j t proportion has sci5ce ju/ifi$ itself2 & 9 ! same proportion has ! ,conque/ ( ,nature be5 c>ri$ t[>d completion4 ,,ii ,,h[ ,,"w ,,is ,,done ,! ^w en]gy implies capacity to d "w4 ,"w1 consid]$ 9 ! ab/ract1 consi/s 9 ! mov+ ( p>ticles ( matt] aga9/ "s oppos+ =ce1 or 9 aid ( previ\sly act+ =ces4 ,9 ! la/ analysis1 all en]gy manife/s itself ei!r z a pu% or z a pull4 ,b !re is a modification ( pu% & pull :i* is famili> to ev]yone 9 practice "u ! "n ( pry+4 ,illu/rations may be se5 on e h&1 z :5 a workman pries up a /one1 or :5 a h\sewife pries up a tack ) ! aid ( a hamm]4 ,! pr9ciple "h involv$ is t ( ! lev]--a pr9ciple :i* 9 its v>i\s practical modifications is ev]y:]e utiliz$ 9 me*anics4 ,v seldom inde$ is ! direct pu% or pull utiliz$2 s9ce ! modifi$ pu% or pull1 z repres5t$ by ! lev] 9 its v>i\s modifications ( pulley1 rat*et-:eel1 & ! l1 has long be5 kn[n to meet ! ne$s ( practical me*anics4 ,! v e>lie/ primitive man :o came to use any implem5t :atev]1 ?\gh x 7 only a brok5 /ick1 mu/ h discov]$ ! ess5tial pr9ciple ( ! lev]1 ?\gh x is h>dly necess>y to add t he did n "k 8 discov]y by any su* high-s\nd+ title4 ,:at he did "k1 f practical exp]i5ce1 0 t ) ! aid ( a /ick he c\ld pry up /ones or logs t 7 mu* too heavy to be lift$ )\t ?is aid4 ,?is practical k no d\bt suffic$ = a va/ numb] ( g5]ations ( m5 :o us$ ! lev] habitually1 )\t mak+ specific /udy ( ! relations betwe5 ! =ce exp5d$1 ! l5g?s ( ! two ends ( ! lev]1 & ! weight rais$4 ,su* specific exp]im5ts 7 made1 h[ev]1 m ?an two ?\s& ye>s ago by ! fam\s ,syracusan1 ,ar*im$es4 ,he discov]$--or if "s "o else _h discov]$ x be=e him1 he at lea/ record$ & s ga9s ! cr$it ( discov]y--! specific laws ( ! lev]1 & he also po9t$ out t lev]s1 all act+ on ! same pr9ciple1 may be diff]5t z to _! practical me*anism 9 ?ree ways4 ,fir/1 ! fulcrum may lie betwe5 ! p[] & ! weight1 z 9 ! case ( ! balance ) :i* we 7 j exp]im5t+4 ,?is is call$ a lev] ( ! fir/ class1 & famili> illu/rations ( x are furni%$ by ! pok]1 /eely>d1 or a pair ( scissors4 ,! s-call$ ext5sor muscles ( ! body--^? = example1 t cause ! arm to ext5d--act on ! bones 9 su* a way z to make !m lev]s ( ?is fir/ class4 ,! second type ( lev] is t 9 :i* ! weight lies betwe5 ! =ce & ! fulcrum1 z illu/rat$ by ! :eelb>r[1 or by an ord9>y door4 ,9 ! ?ird class ( lev]s ! p[] is appli$ betwe5 weight & fulcrum1 z illu/rat$ by a pair ( tongs1 ! treadle ( a la!1 or by ! flexor muscles ( ! arm1 op]at+ ^u ! bones ( ! =e>m4 ,b 9 ea* case1 let x be repeat$1 precisely ! same pr9ciples are involv$1 & ! same simple law ( ! relations betwe5 positions ( p[]1 weight1 & fulcrum are ma9ta9$4 ,! practical result is always t a weight ( indef9ite size may be mov$ by a p[] indef9itely long4 ,if "o arm ( ! lev] is t5 times z long z ! o!r1 ! p[] ( "o p\nd w lift or balance a t5-p\nd weight2 if ! "o arm is a ?\s& times z long z ! o!r ! p[] ( "o p\nd w lift or balance a ?\s& p\nds4 ,if ! long arm ( ! lev] c\ld be made "s millions ( miles 9 l5g?1 ! p[] t a man c\ld ex]t w\ld balance ! e>?4 ,h[ fully ,ar*im$es realiz$ ! possibilities ( ! lev] is illu/rat$ 9 ! classical rem>k attribut$ to him1 t1 _h he b a fulcrum on :i* to place 8 lev]1 he c\ld move ! _w4 ,z o!rwise quot$1 ! rem>k ( ,ar*im$es 0 t1 _h he a place on :i* to /&1 he c\ld move ! _w1 a rem>k :i* ev5 m ?an ! o!r illu/rates ! full & acute appreciation ( ! laws ( motion2 s9ce1 z we h already po9t$ out1 action & reaction be+ equal1 ! mo/ inf9itesimal pu% mu/ be consid]$ z di/urb+ ev5 ! l>ge/ body4 ,trem5d\s z is ! pull ( gravity by :i* ! e>? is held 9 its orbit1 yet ! smalle/ pu%1 /eadily appli$ f ! direction ( ! sun1 w\ld suffice ultimately to di/urb ! /ability ( our e>?'s motion1 & to pu% x gradually ?r\gh a spiral c\rse f>!r & f>!r away f its pres5t l9e ( elliptical flight4 ,or if1 on ! o!r h&1 ! p]si/5t =ce 7 appli$ f ! side opposite ! sun1 x w\ld suffice ultimately to c>ry ! e>? 9 a spiral c\rse until x plung$ into ! sun itself4 ,inde$ x has be5 que/ion$ 9 mod]n times :e!r x may n be possible t precisely ?is latt] effect is gradually be+ accompli%$1 ?r\gh ! action ( meteorites1 "s millions ( :i* fall out ( space into ! e>?'s atmosph]e e day4 ,if ^! meteorites 7 uni=mly di/ribut$ ?r\gh space & fly+ 9 e direction1 ! fact t ! sun scre5s ! e>? f a c]ta9 numb] ( !m1 w\ld make ! av]age numb] fall+ on ! side away f ! sun great]1 & ?us w\ld 9 ! c\rse ( ages produce ! result j sugge/$4 ,all t c\ld save our e>? f su* a fate w\ld be ! op]ation ( "s c\nt]act+ =ce4 ,su* a c\nt]act+ =ce is p]haps f\nd 9 sol> radiation4 ,x may be add$ t ! di/ribution ( meteorites 9 space is probably too irregul> to make _! influ5ce on ! e>? pr$icable 9 ! pres5t /ate ( sci5ce2 b ! pr9ciple involv$ is no less sure4 ,,:eels ,,& ,,pulleys ,return+ f su* !oretical applications ( ! pr9ciple ( motion1 to ! practicalities ( e-day me*anisms1 we mu/ note "s ( ! applications ?r\gh :i* ! pr9ciple ( ! lev] is made available4 ,( ^! "s ( ! mo/ famili> are :eels1 & ! v>i\s modifications ( :eels utiliz$ 9 pulleys & 9 cogg$ & bevell$ ge>+s4 ,a mom5t's reflection w make x cle> t ! :eel is a lev] ( ! fir/ class1 ( :i* ! axle con/itutes ! fulcrum4 ,! spokes ( ! :eel be+ ( equal l5g?1 weights & =ces appli$ to opposite ends ( any diamet] are1 ( c\rse1 9 equilibrium4 ,x foll[s t :5 a :eel is adju/$ s t a rope may be run ab\t x1 con/itut+ a simple pulley1 a me*anism is develop$ :i* gives no ga9 9 p[]1 b only enables ! op]ator to *ange ! direction ( application ( p[]4 ,9 o!r words1 p\nd weights at ei!r end ( a rope pass$ ab\t a simple pulley are 9 equilibrium & w balance ea* o!r1 & move ?r\gh equal di/ances 9 opposite directions4 ,illu/ration3 ,,horse ,,& ,,cattle ,,p[]4 ,! l>ge picture %[s a model ( a famili> me*anism = utiliz+ horse p[]4 ,! small picture %[s a simil> app>atus 9 actual op]ation1 actuat$ by cattle1 9 contempor>y ,brittany4 ,if1 h[ev]1 two or m pulley :eels are connect$1 to make ! famili> app>atus ( a comp\nd pulley1 we h accompli%$ by an int]e/+ me*anism a virtual application ( ! pr9ciple ( ! long & %ort arm ( ! lev]1 & ! relations betwe5 ! weight at ! loose end ( ! rope & ! weight atta*$ to ! block :i* con/itutes virtually ! %ort end ( ! lev]1 may be v>i$ indef9itely1 accord+ to ! numb] ( pulley-:eels t are us$4 ,a p\nd weight may be made to balance a ?\s&-p\nd weight2 b1 ( c\rse1 our famili> pr9ciple /ill hold+1 ! p\nd weight mu/ move ?r\gh a di/ance ( a ?\s& feet 9 ord] to move a ?\s&-p\nd weight ?r\gh a di/ance ( "o foot4 ,famili> illu/rations ( ! application ( ?is pr9ciple may be se5 on e h&2 z :51 = example1 a piano or a safe is rais$ to ! upp] w9d[ ( a build+ by ! ef=ts ( m5 ^: p[]1 if directly exp5d$1 w\ld be altoge!r ineffici5t to /ir ! weight4 ,! pulley 0 d\btless inv5t$ at a mu* lat] /age ( human progress ?an ! simple lev]4 ,x 01 h[ev]1 well kn[n to ! anci5ts4 ,x 0 probably br\ght to its highe/ /ate ( practical p]fection by ,ar*im$es1 ^: exp]im5ts are fam\s ?r\gh ! n>rative ( ,plut>*4 ,x w be recall$ t ,ar*im$es amaz$ ! ,syracusan g5]al by con/ruct+ an app>atus t enabl$ him1 sitt+ on %ore1 to drag a pond]\s galley f ! wat]4 ,plut>* does n describe 9 detail ! app>atus ) :i* ?is 0 accompli%$1 b x is obvi\s f 8 description ( :at took place1 t x mu/ h be5 a sy/em ( pulleys4 ,x w be obs]v$ t ! pulley is a me*anism t enables ! us] to transmit p[] to a di/ance4 ,b ?is inde$ is true 9 a c]ta9 s5se ( e =m ( lev]4 ,numb]less o!r contrivances are 9 use by :i* p[] is transmitt$1 ?r\gh utilization ( ! same pr9ciple ( ! lev]1 ei!r ?r\gh a %ort or ?r\gh a relatively long di/ance4 ,a famili> illu/ration is ! w9dlass1 :i* consi/s ( a cyl9d] rotat+ on an axis propell$ by a long h&le1 a rope be+ w\nd ab\t ! cyl9d]4 ,?is is a lev] ( ! second class1 ! axis act+ z fulcrum1 & ! rope op]at+ ab\t ! circumf]5ce ( ! cyl9d] typify+ ! weight1 :i* may be actually at a consid]able di/ance1 z 9 ! case ( ! old-fa%ion$ well ) its w9dlass & bucket1 or ( ! simple =m ( d]rick sometimes call$ a %e]legs4 ,,o!r ,,means ,,( ,,transmitt+ ,,p[] ,p[] is transmitt$ directly f "o "p ( a ma*9e to ano!r1 9 ! case ( a great v>iety ( ma*9es1 ) ! aid ( cogg$ ge>+ :eels ( v>i\s sizes4 ,! modifications ( detail 9 ! application ( ^! :eels may be almo/ inf9ite1 b ! pr9ciple involv$ is always ! same4 ,! case ( two :eels too!d ab\t ! circumf]5ce1 ! tee? ( ! two :eels fitt+ into "o ano!r1 illu/rates ! pr9ciple involv$4 ,a consid]ation ( ! me*anism w %[ t "h we h virtually a lev] fix$ at bo? ends1 repres5t$ by ! radii ( ! two :eels1 ! p[] be+ appli$ ?r\gh ! axle ( "o :eel1 & ! weight1 = purposes ( calculation1 be+ repres5t$ by ! pressure ( ! tee? ( "o :eel ^u ^? ( ! o!r4 ,s ?is becomes a lev] ( ! second class1 & ! relations ( p[] betwe5 ! two :eels are easily calculat$ f ! relative l5g?s ( ! radii4 ,if1 = example1 "o radius is twice z long z ! o!r1 ! transmission ( p[] w be1 obvi\sly1 9 ! proportion ( two to "o1 & meantime ! di/ance trav]s$ by ! circumf]5ce ( "o :eel w be twice z great z t trav]s$ by ! o!r4 ,a modification ( ! too!d :eel is furni%$ by :eels :i* may be sep>at$ by a consid]able di/ance1 & ! circumf]5ces ( :i* are connect$ by a belt or by a *a94 ,! pr9ciple ( action "h is precisely ! same1 ! belt or *a9 s]v+ m]ely z a means ( l5g!n+ out our lev]4 ,! relative sizes ( ! :eels1 & n ! l5g? ( ! belt or *a91 is ! det]m9+ factor z reg>ds ! relative =ces requir$ to make ! :eels revolve4 ,x is obvi\s all along1 ( c\rse1 s9ce action & reaction are equal1 t all ( ! relations 9 "q are reciprocal4 ,:51 = example1 we speak ( a p\nd weight on ! long end ( a lev] balanc+ a t5-p\nd weight on ! %ort end1 x is equally appropriate to speak ( ! t5-p\nd weight z balanc+ ! "o-p\nd weight4 ,simil>ly1 :5 p[] is appli$ to ! lev]1 x may be appli$ at ei!r end4 ,ord9>ily1 to be sure1 ! p[] is appli$ at ! long end1 s9ce ! object is to lift ! heavy weight2 b 9 complicat$ ma*9]y x q z (t5 happ5s t ^! conditions are rev]s$1 & !n x becomes desirable to apply /rong p[] to ! %ort end ( ! lev]1 9 ord] t ! relatively small weight may be c>ri$ ?r\gh ! long di/ance4 ,9 ! int]-relations ( ge>+ :eels1 su* conditions v frequ5tly obta91 practical ends be+ met by a s]ies ( :eels ( diff]5t sizes4 ,b ! s+le rule1 already s (t5 outl9$1 ev]y:]e holds--:]ev] !re is ga9 ( p[] !re is loss ( di/ance1 & we c ga9 di/ance only by los+ p[]4 ,! words ga9 & loss 9 ?is application are 9 a s5se misnom]s1 s9ce1 z we h already se51 ga9 & loss are only app>5t1 b _! conv5i5ce ( application is obvi\s4 ,a famili> case 9 :i* !re is fir/ loss ( spe$ & ga9 ( p[]1 & !n ga9 ( spe$ at ! exp5se ( p[] 9 ! same me*anism1 is furni%$ by ! bicycle1 :]e 7#a7 ! crank %aft turns ! sprocket :eel t con/itutes a lev] ( ! second class ) ga9 ( p[]2 :]e 7#b7 p[] is fur!r augm5t$ ?r\gh transmission f ! relatively l>ge sprocket :eel to ! small sprocket ( ! axle2 & :]e 7#c7 !re is great loss ( p[] & correspond+ ga9 ( spe$ 9 transmitt+ ! =ce f ! small sprocket :eel at ! axle to ! rubb] rim ( ! bicycle prop]1 ?is la/ transmission repres5t+ a lev] ( ! ?ird class4 ,! net ga9 ( spe$ is tangibly repres5t$ by ! diff]5ce 9 di/ance trav]s$ by ! man's feet 9 revolv+ ! p$als1 & ! actual di/ance cov]$ by ! bicycle4 ,,incl9$ ,,planes ,,& ,,d]ricks ,a less obvi\s application ( ! pr9ciple ( reciprocal equival5ce ( di/ance & weight is furni%$ by ! incl9$ plane1 a famili> me*anism ) ! aid ( :i* a great ga9 ( p[] is possible4 ,! incl9$ plane1 l ! lev]1 has be5 kn[n f remote/ antiquity4 ,its utility 0 probably discov]$ by almo/ ! e>lie/ build]s4 ,diodorus ,siculus tells u t ! great pyramids ( ,egypt 7 con/ruct$ ) ! aid ( incl9$ planes1 bas$ on a f\ndation ( e>? pil$ ab\t ! pyramids4 ,diodorus1 liv+ at a p]iod remov$ by "s ?\s&s ( ye>s f ! day ( ! build+ ( ! pyramids1 may or may n h voic$ & record$ an au!ntic tradition1 b we may well believe t ! pr9ciple ( ! incl9$ plane 0 l>gely drawn ^u by ! me*anics ( old ,egypt1 z by lat] peoples4 ,! law ( ! incl9$ plane is t 9 ord] to e/abli% equilibrium betwe5 two weights1 ! "o mu/ be to ! o!r z ! height ( ! incl9$ plane is to its l5g?4 ,! /eep] ! incl9$ plane1 !re=e1 ! less w be ! ga9 9 p[]2 a me*anical pr9ciple :i* famili> exp]i5ce or ! simple/ exp]im5t w readily corroborate4 ,9 its elem5tal =m ! incl9$ plane is n us$ v l>gely 9 mod]n ma*9]y1 b its modifi$ =m ( ! w$ge & ! screw h m utility4 ,! screw1 inde$1 :i* is obvi\sly an incl9$ plane adju/$ spirally ab\t a cyl9d] or a cone1 is famili> to ev]yone1 & is con/antly utiliz$ 9 apply+ p[]4 ,! crane or d]rick furni%es a famili> b relatively elaborate illu/ration ( a me*anism = ! transmission ( p[]1 9 :i* all ! v>i\s devices hi!rto ref]r$ to are comb9$1 )\t ! introduction ( any new pr9ciple4 ,d]ricks h be5 employ$ f a v e>ly day4 ,! batt]+-rams ( ! anci5t ,egyptians & ,babylonians1 = example1 7 virtually d]ricks2 & no d\bt ! same p us$ ! device 9 rais+ /ones to build _! temples & city walls1 & 9 putt+ into position su* massive sculptures z ! obelisks ( ,egypt & ! mon/] grav5 bulls & lions ( ,n9eveh & ,babylon4 ,illu/ration3 ,,cranes ,,& ,,d]ricks4 ,! upp] figure %[s a float+ d]rick1 ! l[] "r-h& figure a comb9$ d]rick & weigh+ ma*9e1 & ! l[] left-h& figure a s-call$ %e]legs1 :i* is a simple d]rick & w9dlass op]at$ by h& or by /eam p[] ) ! aid ( comp\nd pulleys4 ,! mod]n d]rick1 made ( /eel1 & op]at$ by /eam or electricity1 capable ( lift+ tons1 yet absolutely ob$i5t to ! h& ( ! eng9e]1 is a really wond]ful piece ( me*anism4 ,a /eam-scoop1 = example1 excavat+ a gravel bank1 seems almo/ a ?+ ( intellig5ce2 z x gores into ! bank scoop+ up p]haps a half ton ( e>?1 its upw>d sweep+ head rem9ds "o ( an angry bull4 ,!n z x sw+s leisurely ab\t & dis*>ges its load at j ! "r spot into an await+ c>1 its h+$ bottom sw+s back & =? two or ?ree times be=e clos+1 ) curi\s resemblance to ! jaw ( a dog2 ! simil>ity be+ height5$ by ! squ>e bull-dog-head$ %ape ( ! scoop itself4 ,yet ?is rem>kable contrivance1 ) all its massive /eel beams & *a9s & cog :eels1 employs no o!r pr9ciples ?an ! simple ones ( lev] & pulley & incl9$ plane t we h j exam9$4 ,! p[] t mu/ be appli$ to produce a giv5 effect may be calculat$ to a nicety4 ,! capacities ( ! ma*9e are fully pr$et]m9$ 9 advance ( its actual con/ruction4 ,b ( c\rse ?is is equally true ( e o!r =m ( p[]-transmitt] ) :i* ! mod]n me*anical eng9e] has to deal4 ,,friction ,9 mak+ su* calculations1 h[ev]1 !re is an additional elem5t :i* ! eng9e] mu/ consid]1 b :i* we h hi!rto disreg>d$4 ,9 all me?ods ( transmission ( p[]1 & inde$ 9 all cases ( ! contact ( "o sub/ance ) ano!r1 !re is an elem5t ( loss ?r\gh friction4 ,?is is due to ! fact t no sub/ance is smoo? except 9 a relative s5se4 ,ev5 ! mo/ highly poli%$ glass or /eel1 :5 view$ "u ! microscope1 pres5ts a surface cov]$ ) ind5tations & rugosities4 ,?is granul> surface ( ev5 seem+ly smoo? objects1 is easily visualiz$ ?r\gh ! analogy ( numb]less sub/ances t are visibly r\gh4 ,yet ! va/ practical importance ( ?is r\ghness is seldom consid]$ by ! casual obs]v]4 ,9 po9t ( fact1 7 x n = ! r\gh5$ surface ( all mat]ials ) :i* we come 9 contact1 x w\ld be impossible = any animal or man to walk1 nor c\ld we hold any?+ 9 our h&s4 ,anyone :o has attempt$ to h&le a fi%1 p>ticul>ly an eel1 fre% f ! wat]1 w recall ! difficulty ) :i* its slipp]y surface 0 held2 b x may n occur to ev]yone :o has _h ?is exp]i5ce t all o!r objects w\ld simil>ly slip f ! h&1 _h _! surfaces a simil> smoo?ness4 ,! slipp]y "* ( ! eel is1 ( c\rse1 due 9 l>ge "p to ! relatively smoo? surface ( its sk91 b p>tly also to ! lubricant ) :i* x is cov]$4 ,any sub/ance may be r5d]$ some:at smoo!r by prop] lubrication2 x is necess>y1 h[ev]1 t ! lubricant %\ld be some?+ :i* is n absorb$ by ! sub/ance4 ,?us1 wood is giv5 increas$ friction by be+ moi/5$ ) oil1 b1 on ! o!r h&1 is made slipp]y if cov]$ ) graphite1 soap1 or any o!r fatty sub/ances t x does n absorb4 ,recall+ ! m or less r\gh5$ surface ( all objects1 ! s\rce ( friction is readily und]/ood4 ,x dep5ds ^u ! actual jutt+ ( ! r\gh5$ surfaces1 "o ^u ! o!r4 ,x virtually con/itutes a =ce act+ 9 opposition to ! motion ( any two surfaces ^u ea* o!r4 ,z betwe5 any diff]5t mat]ials1 "u giv5 conditions1 x v>ies ) ! pressure1 9 a def9ite & measurable rate1 :i* is spok5 ( z ! coeffici5t ( friction = ! p>ticul> sub/ances4 ,x is v mu* great] :]e ! two sub/ances slide ov] "o ano!r ?an :]e ! "o rolls ^u ! o!r1 z 9 ! case ( ! :eel4 ,! latt] illu/rates :at is call$ roll+ friction1 & 9 practical me*anics x is us$ con/antly to decrease ! loss--z1 = example1 9 ! :eels ( wagons & c>s4 ,! use ( lubricants to decrease friction is equally famili>4 ,)\t !m1 z ev]yone kn[s1 x w\ld be impossible to run any :eel cont9u\sly ^u an axle at high spe$ = m ?an a v brief p]iod1 ow+ to ! great heat develop$ ?r\gh friction4 ,friction is inde$ a p]petual antagoni/ ( ! me*anician1 & we %all see endless illu/rations ( ! me?ods he employs to m9imize its influ5ce4 ,on ! o!r h&1 we mu/ recall t 7 x r5d]$ absolutely nil1 8 ma*9]y w\ld all be useless4 ,! c> :eel1 = example1 w\ld revolve indef9itely )\t /irr+ ! tra91 7 !re absolutely no friction betwe5 x & ! rail4 ,,available ,,s\rces ,,( ,,en]gy ,we h po9t$ out t e body :atev] conta9s a c]ta9 /ore ( en]gy1 b x has equally be5 call$ to our att5tion t1 9 ! ma91 ^! /ores ( en]gy are n available = practical use4 ,!re are1 h[ev]1 v>i\s great natural repositories ( en]gy ^u :i* man is able to draw4 ,! *ief ( ^! are1 fir/1 ! muscul> en]gy ( man himself & ( animals2 second1 ! en]gy ( air 9 motion2 ?ird1 ! en]gy ( wat] 9 motion or at an elevation2 & f\r?1 ! molecul> & atomic en]gies /or$ 9 coal1 wood1 & o!r combu/ible mat]ials4 ,to ^! we %\ld probably add ! en]gy ( radio-active sub/ances--a =m ( en]gy only rec5tly discov]$ & n z yet available on a l>ge scale1 b :i* may sometime become s1 :5 new supplies ( radio-active mat]ials h be5 discov]$4 ,x w be ! object ( succe$+ *apt]s to po9t out ! practical ways 9 :i* ^! v>i\s /ores ( en]gy are drawn ^u & made to d "w = man's b5efit4 ,,iii ,,! ,,animal ,,ma*9e ,! muscul> sy/em is n only ! olde/ ma*9e 9 exi/5ce1 b also ! mo/ complex4 ,moreov]1 x is o!rwise entitl$ to prec$5ce1 = ev5 to-day1 9 ?is s-call$ age ( /eam & electricity1 ! muscul> sy/em rema9s by f> ! mo/ important ( all ma*9es4 ,9 ! ,unit$ ,/ates alone !re are "s tw5ty million horses do+ "w = man2 & ( c\rse no ma*9e ( any sort is ev] put 9 motion or cont9ues indef9itely 9 op]ation )\t aid suppli$ by human muscles4 ,all 9 all1 !n1 x is impossible to ov]e/imate ! importance ( ?is muscul> ma*9e :i* is at once ! olde/ & ! mo/ la/+ ( all sy/ems ( utiliz+ en]gy4 ,! physical laws t gov]n ! animal ma*9e are precisely simil> to ^? t are appli$ to o!r me*anisms4 ,all ! laws t h be5 call$ to our att5tion mu/ !re=e be und]/ood z apply+ fully to ! muscul> me*anism4 ,b 9 addition to ^! ! muscul> sy/em has c]ta9 laws or me?ods ( action ( its own1 "s ( :i* are n v cle>ly und]/ood4 ,! prime my/]y conc]n+ ! muscle is its wond]ful prop]ty ( contract+4 ,= practical purposes we may say t x has no o!r prop]ty2 ! sole function ( ! muscle is to contract4 ,x c1 ( c\rse1 relax1 also1 to make ready = ano!r contraction1 b ?is is ! full ext5t ( its activities4 ,a microscopic exam9ation ( ! muscle %[s t x is compos$ ( m9ute fibres1 ea* ( :i* on contraction swells up into a sp9dle %ape4 ,a mass ( su* fibres aggregat$ toge!r con/itutes a muscle1 & e muscle is atta*$ at ei!r extremity1 by means ( a t5don1 to a bone4 ,bo? extremities ( a muscle are nev] atta*$ to ! same bone--o!rwise ! muscle w\ld be absolutely useless4 ,usually !re is only a s+le bone betwe5 ! two ends ( a muscle1 b 9 exceptional cases !re may be m4 ,z a rule1 ! ma9 body ( a muscle lies along ! bone to :i* "o end ( x is atta*$1 ! o!r end ( ! muscle be+ atta*$ to ! contigu\s bone plac$ n f> f ! po9t4 ,! fir/ bone1 !n1 s]ves z a fulcrum on :i* ! second bone moves z a lev]1 &1 z already po9t$ out1 ! famili> laws ( ! lev] op]ate "h z fully z 9 ! inanimate _w4 ,b a mom5t's reflection w make x cle> t ! object effect$ by ?is me*anism is ! increase ( motion ) relative loss ( en]gy4 ,9 o!r words1 ! muscul> =ce is appli$ to ! %ort end ( ! lev]1 & a f> great] exp5diture ( =ce is requir$ :5 ! muscle contracts ?an ! p[] ext]nally manife/$ w\ld seem to indicate4 ,a mom5t's consid]ation ( ! me*anism ( ! arm1 hav+ reg>d to ! biceps muscle :i* flexes ! elb[1 w make ?is cle>4 ,if a weight is held 9 ! h& x is p]haps twelve in*es f ! elb[4 ,if1 :ile hold+ ! weight1 y w grasp ! elb[ ) ! o!r h&1 y w feel ! po9t ( atta*m5t ( ! biceps1 & discov] t x does n seem to be1 r\ghly speak+1 m ?an ab\t an in* f ! jo9t4 ,obvi\sly1 !n1 if y are lift+ a p\nd weight1 ! actual equival5t ( en]gy exp5d$ by ! contract+ biceps mu/ be twelve p\nds4 ,b1 9 ! meantime1 :5 ! p\nd weight 9 y\r h& moves ?r\gh ! space ( "o in*1 ! muscle has contract$ by "o-twelf? ( an in*2 & y may sweep ! weight ?r\gh a di/ance ( two feet by utiliz+ ! two-in* contraction1 :i* repres5ts ab\t ! capacity ( ! muscle4 ,a simil> consid]ation ( ! muscles ( ! legs w %[ h[ ! muscul> sy/em :i* is susceptible ( b trifl+ v>iation 9 size1 gives to ! animal great locomotive p[]4 ,) ! aid ( a s]ies ( lev]s1 repres5t$ by ! bones ( our ?ighs1 legs1 & feet1 we are able to /ride along1 cov]+ ?ree or f\r feet at ea* /ep1 :ile no set ( ! muscles t effect ?is propulsion v>ies 9 l5g? by m ?an two or ?ree in*es4 ,x appe>s1 !n1 t ! muscul> sy/em gives a m>vel\s illu/ration ( capacity = /or+ en]gy 9 a compact =m & utiliz+ x = ! developm5t ( motion4 ,,! ,,two ,,types ,,( ,,muscles ,! muscles ( animals & m5 alike are divid$ into two sy/ems1 "o call$ volunt>y1 ! o!r involunt>y4 ,! volunt>y muscles1 z _! "n implies1 are subject to ! influ5ce ( ! w1 & "u ord9>y conditions contract 9 response to ! volunt>y n]v\s impulses4 ,c]ta9 sets ( !m1 inde$1 z ^? hav+ to d ) respiration1 h develop$ a t5d5cy to rhy?mical action ?r\gh long use1 & ord9>ily p]=m _! functions )\t volunt>y guidance4 ,_! function may1 h[ev]1 become volunt>y :5 att5tion is direct$ t[>d x1 & is !n subject to ! action ( ! w )9 c]ta9 b\nds4 ,%\ld a volunt>y attempt be made1 h[ev]1 to prev5t _! action indef9itely1 ! s-call$ reflex me*anism pres5tly ass]ts itself4 ,all ( :i* may be easily atte/$ by anyone :o w attempt to /op brea?+4 ,all sy/ems ( volunt>y muscles are subject to ! influ5ce ( habit1 & may assume activities t are only p>tially recogniz$ by consci\sness4 ,z an illu/ration 9 po9t1 ! muscles involv$ 9 walk+ come1 9 ! case ( e adult1 to p]=m _! function )\t direct guidance ( ! w4 ,su* 0 n ! case1 h[ev]1 9 ! e>ly /age ( _! developm5t1 z ! obs]vation ( any *ild le>n+ to walk w amply demon/rate4 ,9 ! case ( animals1 h[ev]1 ev5 ^? muscles are s "u ! impress ( h]$it>y t5d5cies z to p]=m _! functions spontane\sly almo/ f ! mom5t ( bir?4 ,^!1 h[ev]1 are physiological details t ne$ n conc]n u "h4 ,x suffices to recall t ! volunt>y muscles may be direct$ by ! w1 & inde$ are always "u :at may be t]m$ subconsci\s direction1 ev5 :5 ! consci\s att5tion is n direct$ to !m4 ,! /rictly involunt>y muscles1 h[ev]1 are plac$ absolutely beyond control ( ! w4 ,! mo/ important ( ^! muscles are ^? t con/itute ! he>t & ! diaphragm1 & t ent] into ! sub/ance ( ! walls ( blood vessels1 & ( ! abdom9al organs4 ,x is obvi\s t ! function+ ( ^! important organs c\ld n advantage\sly be left to ! direction ( ! w2 & s1 9 ! long c\rse ( evolution !y h le>n$1 z x 71 to take c>e ( !mselves1 & 9 s do+ to take c>e ( ! organism1 to ! life ( :i* !y are s absolutely ess5tial4 ,z ! physiologi/ views ! matt]1 no organism c\ld h develop$ :i* did n correspond+ly develop su* involunt>y action ( ! vital organs4 ,x w be se5 t ! involunt>y muscles diff] f ! volunt>y muscles 9 t !y are n connect$ ) bones4 ,in/ead ( be+ ?us atta*$ to solid lev]s1 !y are annul> 9 /ructure1 & 9 contract+ virtually *ange ! size ( ! r+ :i* _! sub/ance con/itutes4 ,ea* fibre 9 contract+ may be ?\ght ( z pull+ aga9/ o!r fibres1 in/ead ( aga9/ a bony surface1 & ! jo9t action *anges ! size ( ! organ1 z is obvi\s 9 ! puls+ ( ! he>t4 ,?\gh ! rhy?mical contractions ( ! involunt>y muscles are indep5d5t ( volunt>y control1 x mu/ n be suppos$ t !y are indep5d5t ( ! control ( ! c5tral n]v\s me*anism4 ,on ! contr>y1 ! n]ve supply s5t out f ! bra9 to ! he>t & to ! abdom9al organs is z pl5tiful & z important z t s5t to ! volunt>y muscles4 ,!re is a c5tre 9 ! bra9 sc>cely l>g] ?an ! head ( a p91 ! de/ruction ( :i* w cause ! he>t in/antly to cease beat+ =ev]4 ,f ?is c5tre1 !n1 & f ! o!r c5tres ( ! bra91 impulses are con/antly s5t to ! involunt>y muscles1 :i* det]m9e ! rate ( activity4 ,nor are ^! c5tres absolutely indep5d5t ( ! seat ( consci\sness1 z anyone w admit :o recalls ! v>i$ *anges 9 ! he>t's action "u /ress ( v>y+ emotions4 ,t ! volunt>y muscles are controll$ by ! c5tral n]v\s me*anism ne$s no pro( beyond ! appeal to our p]sonal exp]i5ces ( e mom5t4 ,y desire "s object t lies on ! table 9 front ( y1 & imm$iately y\r h&1 ?anks to ! elaborate muscul> me*anism1 rea*es out & grasps x4 ,& ?is act is b typical ( ! ?\s& activities t make up our e-day life4 ,ev]yone is aw>e t ! *annel ( communication betwe5 ! bra9 & ! muscul> sy/em is f\nd 9 a sy/em ( n]ves1 :i* x is natural n[-a-days to lik5 to a sy/em ( telegraph wires4 ,we speak ( ! impulse g5]at$ 9 ! bra9 z be+ transmitt$ along ! n]ves to ! muscle1 caus+ t to contract4 ,we are ev5 able to measure ! spe$ ( transf] ( su* an impulse4 ,x is f\nd to move ) relative sl[ness1 compass+ only ab\t "o hundr$ & twelve feet p] second1 be+ 9 ?is reg>d v unlike ! electric curr5t ) :i* x is s (t5 comp>$4 ,b ! precise nature ( ?is impulse is unkn[n4 ,its effect1 h[ev]1 is made tangible 9 ! muscul> contraction :i* x is its sole purpose to produce4 ,! ess5tial influ5ce ( ! n]ve impulse 9 ! transaction is easily demon/rable2 = if ! n]ve cord is sev]$1 z (t5 happ5s 9 accid5ts1 ! muscle suppli$ by t n]ve imm$iately loses its p[] ( volunt>y contraction4 ,x becomes p>alyz$1 z ! say+ is4 ,,! ,,nature ,,( ,,muscul> ,,action ,pay+ he$1 n[1 to ! muscle itself1 x mu/ be freely admitt$ t1 9 ! la/ analysis1 ! activities ( ! sub/ance are z my/]i\s & z inexplicable z are ^? involv$ 9 ! n]v\s me*anism4 ,x is easy to demon/rate t :at we h j spok5 ( z a muscle fibre consi/s 9 reality ( a little tube ( liquid protoplasm1 & t ! *ange 9 %ape ( ?is protoplasm con/itutes ! contraction ( :i* we are all along speak+4 ,b j :at molecul> & atomic *anges are involv$ 9 ?is *ange ( =m ( ! protoplasm1 we _c say4 ,we "k t ! p[] to contract is ! "o univ]sal attribute ( liv+ protoplasm4 ,?is p[] is equally wond]ful & equally inexplicable1 :e!r manife/$ 9 ! case ( ! muscle cell or 9 ! case ( su* a =mless s+le-cell$ creature z ! amoeba4 ,:5 we "k m ( molecul> & atomic =ce1 we may p]haps be able to =m a m5tal picture ( :at goes on 9 ! /ructure ( protoplasm :5 x ?us *anges ! %ape ( its mass4 ,until !n1 we mu/ be cont5t to accept ! fact z be+ ! vital "o ^u :i* all ! movem5ts ( animate creatures dep5d4 ,b if1 "h z else:]e1 ! ultimate activities ( molecules & atoms lie beyond our k51 we may nev]!less ga9 an insight into ! nature ( ! sub/ances involv$4 ,we "k1 = example1 t ! *ief con/itu5ts ( all protoplasm are c>bon1 hydrog51 oxyg51 & nitrog52 & t ) ^! ma9 elem5ts !re are traces ( v>i\s o!r elem5ts su* z iron1 sulphur1 phosphorus1 & sundry salts4 ,we "k t :5 ! muscle contracts "s ( ^! con/itu5ts are dis>rang$ ?r\gh :at is spok5 ( z *emical decomposition1 & t !re results a *ange 9 ! sub/ance ( ! protoplasm1 accompani$ by ! excretion ( a c]ta9 portion ( its con/itu5ts1 & by ! lib]ation ( heat4 ,c>bonic acid gas1 = example1 is g5]at$ & is swept away f ! muscul> tissues 9 ! ev] active blood/reams1 to be c>ri$ to ! lungs & !re expell$--x be+ a noxi\s poison1 fatal to life if reta9$ 9 l>ge quantities4 ,equally noxi\s are o!r sub/ances su* z uric acid & its comp\nds1 :i* are also results ( ! break+ d[n ( tissue t att5ds muscul> action4 ,9 a ^w1 !re is an incessant =mation ( wa/e products1 due to muscul> activity1 ! removal ( :i* requires ! con/ant s]vice ( ! purify+ /reams ( blood & ( ! v>i\s excretory organs4 ,b ?is con/ant outfl[ ( wa/e products f ! muscle necessitates1 ( c\rse1 9 accordance ) ! laws ( ! cons]vation ( matt] & ( en]gy1 an equally con/ant supply ( new matt] to take ! place ( ! old4 ,?is supply ( :at is virtually fuel to be consum$1 enabl+ ! muscle to p]=m its "w1 is br\ght to ! muscle ?r\gh ! /reams ( blood :i* fl[ f ! he>t 9 ! art]ial *annels1 & 9 "p also ?r\gh ! lymphatic sy/em4 ,! blood itself ga9s its supply f ! dige/ive sy/em & f ! lungs4 ,! dige/ive sy/em supplies wat]1 t all-ess5tial dilu5t1 & a great v>iety ( comp\nds elaborat$ into ! prop] pabulum2 :ile ! vital function ( ! lungs is to supply oxyg51 :i* mu/ be incessantly pres5t 9 ord] t ! combu/ion :i* att5ds muscul> activity may take place4 ,:at virtually happ5s is t fuel is s5t f ! dige/ive sy/em to be burn$ 9 ! muscul> sy/em1 ) ! aid ( oxyg5 br\ght f ! lungs4 ,9 ?is view1 ! muscul> app>atus is a species ( heat eng9e4 ,9 po9t ( fact1 x is a curi\sly delicate "o z reg>ds ! range ( conditions )9 :i* x is able to act4 ,! temp]ature ( any giv5 organism is almo/ inv>iable2 ! human body1 = example1 ma9ta9s an av]age temp]ature ( #ih-b_/e degrees1 ,fahr5heit4 ,! range ( v>iation f ?is temp]ature 9 conditions ( heal? is r>ely m ?an a fraction ( a degree2 & ev5 "u /ress ( ! mo/ sev]e fev] ! temp]ature nev] rises m ?an ab\t eight degrees )\t a fatal result4 ,t an organism :i* is produc+ heat 9 su* v>y+ quantities ?r\gh its v>y+ muscul> activities %\ld ma9ta9 su* an equilibrium ( temp]ature1 w\ld seem "o ( ! mo/ m>vel\s ( facts1 7 x n s famili>4 ,! physical means by :i* ! heat ?us g5]at$ is rapidly giv5 (f1 on occasion1 to meet ! v>y+ conditions ( muscul> activity1 is l>gely dep5d5t ^u ! control ( ! blood supply1 9 :i* involunt>y muscles1 simil> to ^? ( ! he>t1 are conc]n$4 ,9 times ( great muscul> activity1 :5 ! production ( heat is relatively enorm\s1 ! art]ioles t supply ! surface ( ! body are rapidly dilat$ s t a prepond]ance ( blood circulates at ! surface ( ! body1 :]e x may readily radiate its heat into space2 ! va/ sy/em ( p]spiratory ducts1 ) :i* ! sk9 is ev]y:]e suppli$1 aid+ enorm\sly 9 facilitat+ ?is result1 ?r\gh ! secretion ( a film ( p]spiration1 :i* 9 evaporat+ takes up l>ge quantities ( heat4 ,! flu%$1 p]spir+ face ( a p]son :o has viol5tly ex]cis$ gives a famili> pro( ( ^! physiological *anges2 & ! contr>y condition1 9 :i* ! p]iph]al circulation is re/rict$1 & 9 :i* ! pores are clos$1 is equally famili>4 ,moreov]1 ! same cutane\s me*anism is effici5t 9 af=d+ ! organism protection f ! *anges ( ext]nal temp]ature2 ?\gh ! human ma*9e1 ?anks to ! pamp]+ influ5ce ( civilization1 requires additional protection 9 ! =m ( clo?+4 ,,applications ,,( ,,muscul> ,,en]gy ,hav+ ?us outl9$ ! conditions "u :i* ! muscul> ma*9e p]=ms its "w1 we h n[ to consid] briefly ! ext]nal me*anisms ) ! aid ( :i* muscul> en]gy is utiliz$4 ,( c\rse1 ! simple/ application ( ?is p[]1 & ! "o univ]sally employ$ 9 ! animal _w is t 9 :i* a direct pu% or pull is giv5 to ! sub/ance1 ! position ( :i* x is desir$ to *ange4 ,we h already po9t$ out t !re is no ess5tial diff]5ce betwe5 pu%+ & pull+4 ,! fact receives ano!r illu/ration 9 consid]+ ! muscul> me*anism4 ,we speak ( pu%+ :5 we propel some?+ away f a body1 ( pull+ :5 we draw some?+ t[>d x1 yet1 z we h j se51 ea* c be accompli%$ m]ely ?r\gh ! contraction ( a set ( muscles1 act+ on diff]5tly dispos$ lev]s4 ,all ! bodily activities are r$ucible to su* muscul> contractions1 & ! div]sifi$ movem5ts 9 :i* ! organism con/antly indulges are m]ely due to ! l>ge numb] & elaborate arrangem5t ( ! bony lev]s ^u :i* ^! muscles are op]at$4 ,we may well suppose t ! primitive man cont9u$ = a long p]iod ( "t to p]=m all su* labors z he und]took )\t ! aid ( any artificial me*anism2 t is to say1 )\t hav+ le>n$ to ga9 any p[] beyond t :i* ! natural lev]s ( 8 body provid$4 ,a brief obs]vation ( ! actions ( a man p]=m+ any piece ( manual labor w1 h[ev]1 quickly demon/rate h[ +5i\sly ! bodily lev]s are employ$1 & h[ by %ift+ positions ! work] unconsci\sly makes ! mo/ ( a giv5 exp5diture ( en]gy4 ,by b5d+ ! arms & br++ !m close to ! body1 he is able to %ort5 8 lev]s s t he c lift a mu* great] weight ?an he c\ld possibly raise ) ! arms ext5d$4 ,on ! o!r h&1 ) ! ext5d$ arm he c /rike a mu* m p[]ful bl[ ?an ) ! %ort] lev] ( ! flex$ arm4 ,b h[ev] +5i\s ! manipulation ( ! natural lev]s1 a full utilization ( muscul> en]gy is possible only :5 !y are supplem5t$ ) artificial aids1 :i* con/itute primitive pieces ( ma*9]y4 ,^! aids are *iefly ( ?ree types1 namely1 incl9$ planes1 friction r$uc]s1 & lev]s4 ,! use ( ! incl9$ plane 0 v e>ly discov]$ & put into practise 9 *ipp$ implem5ts1 :i* took ! =m ( ! w$ge1 9 su* modifications z axes1 knives1 & spe>s ( metal4 ,all ( ^! implem5ts1 x w be obs]v$1 consi/ ess5tially ( incl9$ planes1 adapt$ = pi]c+ relatively s(t tissues ( wood or fle%1 & h5ce s]v+ purposes ( ! greate/ practical utility4 ,! knife-blade is an extremely ?9 w$ge1 to be utiliz$ by =ce ( pu%+1 )\t any great aid f acquir$ mom5tum4 ,! hat*et1 on ! o!r h&--& its modification ! axe--has its blunt] blade fa/5$ to a h&le2 t ! pr9ciple ( ! w$ge may be utiliz$ at ! long end ( a lev] & ) ! mom5tum ( a sw++ bl[4 ,ages be=e anyone c\ld h expla9$ ! pr9ciple involv$ 9 su* obscur+ t]ms z t1 ! implem5t itself 0 9 use = ! same purpose to :i* x is /ill appli$4 ,inde$1 !re is probably no o!r implem5t t has play$ a l>g] "p 9 ! hi/ory ( human indu/ry4 ,ev5 9 ! ,r\gh ,/one ,age x 0 9 full favor1 & ! e>lie/ metallurgi/s produc$ x 9 bronze & !n 9 iron4 ,! blade ( to-day is made ( ! be/ temp]$ /eel1 & ! h&le or helve ( hickory is giv5 a slight curve t is an improvem5t on ! /raight h&le =m]ly employ$2 b on ! :ole x may be said t ! axe is a surviv+ primitive implem5t t has held its own & demon/rat$ its utility 9 e g5]ation s9ce ! dawn1 n ( hi/ory only1 b ( b>b>ism1 p]haps ev5 ( savag]y4 ,! saw1 consi/+ ess5tially ( a ?9 elongat$ blade1 "o ragg$ or too!d edge1 is a sc>cely less primitive & an equally useful & famili> application ( ! pr9ciple ( ! incl9$ plane--?\gh x requires a mom5t's reflection to see ! mann] ( application4 ,ea* too?1 h[ev] m9ute1 is an incl9$ plane1 calculat$ to slide ov] ! tissue ( wood or /one or iron ev51 yet to te> at ! tissue ) its po9t1 &1 ) ! p[] ( numb]s1 ultimately we> x away4 ,,! ,,:eel ,,& ,,axle ,! primitive friction r$uc]1 :i* cont9ues 9 use to ! pres5t day unmodifi$ 9 pr9ciple1 is ! :eel revolv+ on an axle4 ,d\btless man _h rea*$ a v high /ate ( b>b>ism be=e he inv5t$ su* a :eel4 ,! ,am]ican ,indian1 = example1 knew no bett] me?od ?an to c>ry 8 heavy burd5s on 8 %\ld]s1 or drag !m along ! gr\nd1 ) at mo/ a pair ( p>allel poles or runn]s to modify ! friction2 e move repres5t+ a v wa/eful exp5diture ( en]gy4 ,b ! pre-hi/oric man ( ! old _w _h made ! wond]ful discov]y t a :eel revolv+ on an axle va/ly r$uces ! friction betwe5 a weight & ! e>?1 & ?us enables a man or a woman to convey a load t w\ld be f> beyond 8 or h] unaid$ p[]s4 ,x is well to use bo? g5d]s 9 ?is illu/ration1 s9ce among primitive peoples x is usually ! woman :o is ! be>] ( burd5s4 ,& inde$ to ?is day "o may see ! wom5 ( ,italy & ,g]many be>+ l>ge burd5s on _! backs & heads1 & dragg+ c>ts ab\t ! /reets1 q aft] ! primitive me?od4 ,! m "o consid]s ! me*anism1 ! m "o mu/ m>vel at ! +5uity ( ! pre-hi/oric man :o inv5t$ ! :eel & axle4 ,its utility is suffici5tly obvi\s once ! ?+ has be5 done4 ,9 po9t ( fact1 x s enorm\sly r$uces ! friction t a man may convey t5 times ! burd5 ) its aid t he c )\t x4 ,b h[ 0 ! primitive man1 ) 8 small k ( me*anics1 to pr$ict su* a result8 ,9 po9t ( fact1 ( c\rse1 he made no su* pr$iction4 ,d\btless 8 att5tion 0 fir/ call$ to ! utility ( roll+ bodies by a *ance obs]vation ( dragg+ a burd5 along a pebbly bea*1 or ov] roll+ /ones4 ,! obs]vation ( logs or r\nd /ones roll+ d[n a hill might also h /imulat$ ! imag9ation ( "s inv5tive g5ius4 ,illu/ration3 ,a ,,belgian ,,milk-,,wagon4 ,9 _m ( ! c\ntries ( ,europe ! dog plays an important "p z a bea/ ( burd54 ,/r+5t laws are en=c$ 9 ^! c\ntries to prev5t possible abuse or neglect ( ! animals4 ,probably logs plac$ b5ea? heavy weights1 su* z are /ill employ$ sometimes 9 mov+ h\ses1 7 utiliz$ n[ & aga9 = _m g5]ations be=e ! idea ( a n>r[ section ( a log adju/$ on an axis 0 evolv$4 ,b be t z x may1 ?is idea 0 put into practise be=e ! hi/oric p]iod beg9s1 & we f9d ! e>lie/ civiliz$ races ( :i* we h record--^?1 namely1 ( ,old ,egypt & ( ,old ,babylonia--9 full possession ( ! pr9ciple ( ! :eel z appli$ to vehicles4 ,mod]n me*anics h1 ( c\rse1 improv$ ! me*anism z reg>ds details1 b ! :eels depict$ 9 ,old ,egyptian & ,babylonian inscriptions are curi\sly simil> to ! mo/ mod]n types4 ,inde$1 ! :eel is a /rik+ illu/ration ( a me*anism :i* cont9u$ c5tury aft] c5tury to s]ve ! purposes ( ! practical work]1 ) seem+ly no prospect ( displacem5t4 ,,modifi$ ,,lev]s ,= ! re/1 ! me*anisms :i* primitive man le>n$ e>ly to use 9 add+ to 8 work+ effici5cy1 & :i* are /ill us$ by ! h& labor]1 are virtually all modifications ( our famili> type-implem5t1 ! lev]4 ,a mom5t's reflection w %[ t ! div]sifi$ purposes ( ! cr[b>1 hoe1 %ovel1 hamm]1 drill1 *isel1 are all accompli%$ ) ! aid ( ! same pr9ciples4 ,! cr[b>1 = example1 enables man to rega9 ! p[] :i* he lo/ :5 8 memb]s 7 adapt$ to locomotion4 ,8 h&s1 left to !mselves1 z we h already po9t$ out1 give b inadequate expression to ! p[] ( 8 muscles4 ,b by grasp+ ! long end ( su* a lev] z ! cr[b>1 he is enabl$ to utilize 8 entire weight 9 addition to 8 muscul> /r5g?1 &1 ) ! aid ( ?is lev]1 to lift _m times 8 weight4 ,! hoe1 on ! o!r h&1 becomes virtually a l5g!n$ arm1 enabl+ a v slight muscul> motion to be trans=m$ into ! long sweep ( ! implem5t1 s t ) small exp5diture ( en]gy ! desir$ "w is accompli%$4 ,simil>ly1 ! sl$ge & ! axe l5g!n out ! lev] ( ! arms1 s t great mom5tum is readily acquir$1 & ) ! aid ( in]tia a relatively enorm\s =ce c be appli$4 ,x w be obs]v$ t a labor] 9 rais+ a heavy sl$ge br+s ! head ( ! implem5t ne> 8 body1 ?us %ort5+ ! lev]age & ga9+ p[] at ! exp5se ( spe$2 b ext5ds 8 arms to _! full l5g? z ! sl$ge falls1 hav+ n[ ! aid ( gravitation1 to ga9 ! full advantage ( ! long arm ( ! lev] 9 acquir+ mom5tum4 ,ev5 su* elaborately modifi$ implem5ts z ! treadmill & ! r[boat are op]at$ on ! pr9ciple ( ! lev]4 ,^! also are me*anisms t h come d[n to u f a high antiquity4 ,_! utility1 h[ev]1 has be5 greatly decreas$ 9 mod]n times1 by ! sub/itution ( m elaborate & economical me*anisms = accompli%+ _! respective purposes4 ,! treadmill1 inde$--:i* might be lik5$ to an ov]%ot wat]:eel 9 :i* ! human foot suppli$ ! place ( ! fall+ wat] 9 giv+ p[]--has become obsolete1 ?\gh a modification ( x1 to be driv5 by animal p[]1 is /ill sometimes us$1 z we %all see 9 a mom5t4 ,all ^! are illu/rations ( me*anisms ) ! aid ( :i* human labor is made effective4 ,!y %[ ! devices by :i* primitive man us$ 8 +5uity 9 mak+ 8 muscul> sy/em a m effective ma*9e = ! p]=mance ( "w4 ,b p]haps ! mo/ +5i\s feat ( all :i* our primitive ance/or accompli%$ 0 9 le>n+ to utilize ! muscul> en]gy ( o!r animals4 ,( c\rse ! example 0 always be=e him 9 ! obs]v$ activity ( ! animals on e side4 ,nev]!less1 x 0 d\btless long be=e ! idea sugge/$ itself1 & probably long] /ill be=e x 0 put into practise1 ( utiliz+ ?is almo/ inexhau/ible natural supply ( work+ en]gy4 ,,dome/icat$ ,,animals ,! fir/ animal dome/icat$ is believ$ to h be5 ! dog1 & ?is animal is /ill us$1 z ev]yone kn[s1 z a bea/ ( burd5 9 ! f> ,nor?1 & 9 "s ,european cities1 p>ticul>ly 9 ^? ( ,g]many4 ,subsequ5tly ! ox 0 dome/icat$1 b x is probable t = a va/ p]iod ( "t x 0 us$ = food purposes1 r ?an z a bea/ ( burd54 ,& la/ly ! horse1 ! work] p> excell5ce1 0 made captive by "s ,asiatic tribes hav+ ! g5ius ( inv5tion1 & 9 due c\rse ?is fleete/ ( c>ri]s & mo/ effici5t ( draught animals 0 introduc$ into all civiliz$ nations4 ,d\btless = a long "t ! en]gy ( ! horse 0 utiliz$ 9 an uneconomical way1 ?r\gh b9d+ ! burd5 on its back1 or caus+ x to drag ! burd5 along ! gr\nd4 ,b ?is is inf]5tial1 s9ce1 z we h se51 ! :eel 0 inv5t$ 9 pre-hi/oric times1 & at ! dawn ( hi/ory we f9d ! ,babylonians driv+ h>ness$ horses atta*$ to :eel$ vehicles4 ,f t day to ?is ! me?od ( us+ horse-p[] has n greatly *ang$4 ,! va/ majority ( ! _m millions ( horses t are employ$ e day 9 help+ on ! _w's "w1 use _! /r5g? )\t ga9 or loss ?r\gh lev]age1 & ) only ! aid ( roll+ friction to increase _! capacity z bea/s ( burd54 ,to a c]ta9 ext5t horse-p[] is /ill us$ ) ! aid ( ! modifi$ treadmill j ref]r$ to--consi/+ ess5tially ( an incl9$ plane ( flexible me*anism made into an endless plat=m1 :i* ! horse causes to revolve z he goes ?r\gh ! movem5ts ( walk+ ^u x4 ,9 agricultural di/ricts ?is =m ( p[] is /ill sometimes us$ to run ?re%+ ma*9es1 cid] mills1 wood-saws1 & ! l4 ,ano!r application ( horse-p[] to ! same ends is accompli%$ ?r\gh h>ness+ a horse to a long lev] l ! spoke ( a :eel1 fa/5$ to an axis1 :i* is made to revolve z ! horse walks ab\t x4 ,sev]al horses are sometimes hit*$ to su* a me*anism1 :i* becomes !n a :eel ( sev]al spokes4 ,b ?is me*anism1 :i* 0 common en\gh 9 agricultural di/ricts two or ?ree decades ago1 has be5 practically sup]s$$ 9 rec5t ye>s by ! p]ambulatory /eam eng9e4 ,illu/ration3 ,,two ,,app>atuses ,,= ,,! ,,utilization ,,( ,,animal ,,p[]4 ,! upp] figure %[s ! type ( portable horse-p[] ma*9e us$ = ?re%+ gra9 9 #ahea4 ,! l[] figure is an incl9$-plane horse-ge>4 ,! horse /&s on ! slop+ plat=m ti$ to ! b> 9 front1 s t x is compell$ to walk z ! plat=m rec$es4 ,x is obvi\s t ! am\nt ( "w :i* a horse c accompli% mu/ v>y greatly ) ! size & quality ( ! horse1 & ) ! p>ticul> me?od by :i* its en]gy is appli$4 ,= ! purposes ( comp>ison1 h[ev]1 an arbitr>y am\nt ( "w has be5 fix$ ^u z con/itut+ :at is call$ a horse-p[]4 ,?is am\nt is ! equival5t ( rais+ ?irty-?ree ?\s& p\nds ( weight to ! height ( "o foot 9 "o m9ute4 ,x w\ld be h>d to say j :y ?is p>ticul> /&>d 0 fix$ ^u1 s9ce x c]ta9ly repres5ts m ?an ! av]age capacity ( a horse4 ,x is1 h[ev]1 a /&>d :i* long usage 7x 0 fir/ sugge/$ by ,watt1 ( /eam-eng9e fame7 has r5d]$ conv5i5t1 & "o :i* ! ma*9i/ ref]s to con/antly 9 speak+ ( ! effici5cy ( ! v>i\s types ( artificial ma*9es4 ,all que/ions ( ! exact legitimacy ( ?is p>ticul> /&>d aside1 x 0 highly appropriate t ! labor ( ! horse1 :i* has made up s l>ge a %>e ( ! labor ( ! pa/1 & :i* is /ill s ext5sively utiliz$1 %\ld cont9ue to be tak5 z ! measur+ /&>d ( ! _w's "w4 ,,iv ,,! ,,"w ,,( ,,air ,,& ,,wat] ,! /ore ( en]gy conta9$ 9 ! atmosph]e & 9 ! wat]s ( ! globe is inexhau/ible4 ,its am\nt is beyond all calculation2 or if x 7 vaguely calculat$ ! figures w\ld be q incompreh5sible f _! v magnitude4 ,x is n1 h[ev]1 an altoge!r simple matt] to make ?is en]gy available = ! purposes ( useful "w4 ,we f9d t ?r\gh\t antiquity comp>atively little use 0 made ( ei!r w9d or wat] 9 _! application to ma*9]y4 ,d\btless ! e>lie/ use ( air z a motive p[] 0 ?r\gh ! application ( sails to boats4 ,we "k t ! ,pho5icians us$ a simple =m ( sail1 & no d\bt _! example 0 foll[$ by all ! m>itime peoples ( subsequ5t p]iods4 ,b ! use ( ! sail ev5 by ! ,pho5icians 0 z a comp>atively unimportant accessory to ! galaxies ( o>s1 :i* =m$ ! *ief motive p[]4 ,! elaboration ( sails ( v>i\s types1 adequate 9 ext5t to propel l>ge %ips1 & capable ( be+ adju/$ s z to take advantage ( w9ds bl[+ f almo/ any qu>t]1 0 a developm5t ( ! ,middle ,ages4 ,! possibilities ( "w ) ! aid ( runn+ wat] 7 also b little und]/ood by ! anci5ts4 ,9 ! days ( slave labor x 0 sc>cely wor? :ile to tax man's +5uity to inv5t ma*9es1 s9ce s effici5t a "o 0 provid$ by nature4 ,yet ! prop]ties ( bo? air & wat] 7 /udi$ by v>i\s me*anical philosoph]s1 at ! head ( :om 7 ,ar*im$es1 ^: "w has already be5 ref]r$ to1 & ! fam\s ,alex&rian1 ,ctesibius1 ^: inve/igations became famili> ?r\gh ! publications ( 8 pupil1 ,h]o4 ,p]haps ! mo/ rem>kable device inv5t$ by ,ctesibius 0 a fire-eng9e1 consi/+ ( an arrangem5t ( valves con/itut+ a pump1 & op]at+ on ! pr9ciple :i* is /ill 9 vogue4 ,x is kn[n1 h[ev]1 t ! ,egyptians ( a mu* e>li] p]iod us$ buckets hav+ valves 9 _! bottoms1 & ^! p]haps furni%$ ! f\ndation = ! idea ( ,ctesibius4 ,x is unnecess>y to give details ( ?is fire-eng9e4 ,x may be not$1 h[ev]1 t ! pr9ciple ( ! lev] is ! "o employ$ 9 its op]ation to ga9 p[]4 ,a valve consi/s ess5tially ( any simple h+$ sub/ance1 arrang$ s t x may rise or fall1 alt]nately op5+ & clos+ an ap]ture4 ,a m]e flap ( lea!r1 nail$ on "o edge1 s]ves z a tol]ably effective valve4 ,at lea/ "o ( ! valves us$ by ,ctesibius 0 a h+$ piece ( smoo? metal4 ,a pi/on fitt$ 9 a cyl9d] supplies suction :5 ! lev] is rais$1 & pressure :5 x is compress$1 alt]nately op5+ ! valve & clos+ ! valve ?r\gh :i* ! wat] ent]s ! tube4 ,meantime a second valve alt]nat+ ) ! fir/ p]mits ! wat] to ent] ! *amb] conta9+ air1 :i* ?r\gh its ela/icity & pressure equalizes ! =ce ( ! /ream t is eject$ f ! *amb] ?r\gh ! hose4 ,,suction ,,& ,,pressure ,9 ! con/ruction ( ?is & v>i\s o!r app>atus1 ,ctesibius & ,h]o 7 l$ to make c>eful /udies ( ! ph5om5a ( suction4 ,b 9 ?is !y 7 n alone1 s9ce num]\s ( _! pr$ecessors _h /udi$ ! subject1 & su* an app>atus z ! surgeon's cupp+ glass 0 famili>ly kn[n sev]al c5turies be=e ! ,*ri/ian era4 ,! cupp+ glass1 z p]haps %\ld be expla9$ to ! read] ( ! pres5t day--s9ce ! app>atus w5t out ( vogue 9 ord9>y m$ical practise two or ?ree g5]ations ago--consi/s ( a glass cup 9 :i* ! air is exhau/$1 s z to suck blood f any "p ( ! surface ( a body to :i* x is appli$4 ,h]o describes a me?od ( exhau/+ air by :i* su* suction may be facilitat$4 ,b nei!r he nor any o!r philosoph] ( 8 p]iod at all und]/ood ! real nature ( ?is suction1 not)/&+ _! p]fect famili>ity ) num]\s ( its ph5om5a4 ,x 0 kn[n1 = example1 t :5 a tube clos$ at "o end is fill$ ) wat] & inv]t$ ) ! op5 end b5ea? ! surface ( ! wat]1 ! wat] rema9s 9 ! tube1 al?\gh "o might naturally expect t x w\ld obey ! impulses ( gravitation & run out1 leav+ ! tube empty4 ,a famili> explanation ( ?is & alli$ ph5om5a ?r\gh\t antiquity 0 f\nd 9 ! say+ t ,nature abhors a vacuum4 ,?is explanation1 :i* ( c\rse am\nts to no explanation at all1 is fairly illu/rative ( ! me?od ( metaphysical ^w-juggl+ t s]v$ s l>gely among ! e>li] philosoph]s 9 explanation ( ! my/]ies ( physical sci5ce4 ,! real explanation ( ! ph5om5a ( suction 0 n arriv$ at until ! revival ( le>n+ 9 ! sev5te5? c5tury4 ,!n ,torricelli1 ! pupil ( ,galileo1 demon/rat$ t ! ^w suction1 z commonly appli$1 _h no prop] application2 & t ! ph5om5a hi!rto ascrib$ to x 7 really due to ! pressure ( ! atmosph]e4 ,a vacuum is m]ely an enclos$ space depriv$ ( air1 & ! abhorr5ce t ,nature %[s to su* a space is due to ! fact t air has weight & presses 9 e direction1 & h5ce t5ds to invade e space to :i* x c ga9 access4 ,x 0 pres5tly discov]$ t if ! inv]t$ tube 9 :i* ! wat] /&s 0 made high en\gh1 ! wat] w no long] fill x1 b w s9k to a c]ta9 level4 ,! height at :i* x w /& is ab\t ?irty feet2 above t height a vacuum w be =m$1 :i*1 = "s reason1 ,nature seems n to abhor4 ,! reason is t ! weight ( any giv5 column ( wat] ab\t ?irty feet 9 height is j balanc$ by ! weight ( a correspond+ column ( atmosph]e4 ,! exp]im5ts t gave ! pro( ( ?is 7 made by ! fam\s ,engli%man1 ,boyle4 ,he %[$ t if ! heavy liquid1 m]cury1 is us$ 9 place ( wat]1 !n ! susp5d$ column w be only ab\t ?irty in*es 9 height4 ,! weight or pressure ( ! atmosph]e at sea level1 z measur$ by ^! exp]im5ts1 is ab\t fifte5 p\nds to ! squ>e in*4 ,boyle's fur!r exp]im5ts ) ! air & ) o!r gases develop$ ! fact t ! pressure ex]t$ by any giv5 quantity ( gas is proportional to ! ext]nal pressure to :i* x is subject$1 :i*1 aft] all1 is only a special application ( ! law t action & reaction are equal4 ,! fur!r fact 0 develop$ t "u pressure a gas decreases at a fix$ rate 9 bulk4 ,a g5]al law1 express+ ^! facts 9 ! phrase t d5sity & ela/icity v>y inv]sely ) ! pressure 9 a precise ratio1 0 develop$ by ,boyle & ! ,fr5*man1 ,m>iotte1 indep5d5tly1 & be>s ! "n ( bo? ( its discov]]s4 ,no imm$iate application ( ! law to ! practical purposes ( ! work] 0 made1 h[ev]1 & x is only 9 rec5t ye>s t compress$ air has be5 ext5sively employ$ z a motive p[]4 ,ev5 n[ x has n prov$ a great comm]cial success1 because o!r m economical me?ods ( p[] production are available4 ,9 p>ticul> cases1 h[ev]1 x has a c]ta9 utility1 z a relatively l>ge available s\rce ( en]gy may be cond5s$ into a v small receptacle4 ,a v /rik+ exp]im5t illu/rat+ ! pressure ( ! air 0 made by a fam\s contempor>y ( ,boyle & ,m>iotte1 by ! "n ( ,otto von ,gu]icke4 ,he connect$ an air pump ) a l>ge brass sph]e1 compos$ ( two hemisph]es1 ! edges ( :i* fitt$ smoo?ly1 b 7 n connect$ by any me*anism4 ,"u ord9>y conditions ! hemisph]es w\ld fall ap>t readily1 b von ,gu]icke prov$1 by a fam\s public demon/ration1 t :5 ! air 0 exhau/$ 9 ! sph]e1 teams ( horses pull+ 9 opposite directions on ! hemisph]es c\ld n sep>ate !m4 ,?is is fam\s z ! exp]im5t ( ! ,magdeburg sph]es1 & x is (t5 repeat$ on a small] scale 9 ! mod]n physical laboratory1 to ! a/oni%m5t ( ! tyro 9 physical exp]im5ts4 ,! fir/ "q t usually comes to ! m9d ( anyone :o has p]sonally witness$ su* an exp]im5t1 is ! "q z to h[ ! human body c )/& ! trem5d\s =ce to :i* x is subject$ by an atmosph]e ex]t+ a pressure ( fifte5 p\nds on e squ>e in* ( its surface4 ,! explanation is f\nd 9 ! uni=m di/ribution ( ! pressure1 ! influ5ce ( :i* is ?us c\nt]act$1 & by ! fact t ! tissues !mselves conta9 ev]y:]e a c]ta9 am\nt ( air at ! same pressure4 ,! famili> exp]im5t ( hold+ ! h& ov] an exhau/$ glass cyl9d]--:i* exp]im5t is inde$ b a modification ( ! use ( ! cupp+ glass above ref]r$ to--illu/rates v =cibly ! insupportable difficulties :i* ! human body w\ld enc\nt] 7 n its entire surface uni=mly subject$ to ! atmosph]ic pressure4 ,,air ,,9 ,,motion ,at ab\t ! "t :5 ! sci5tific exp]im5ts ) ! pressure ( gases 7 be+ made1 practical /udies ( ! effects ( masses ( air 9 motion 7 und]tak5 by ! ,dut* philosoph]1 ,s]v9us4 ,! use ( ! w9dmill 9 ,holl& z a means ( g5]at+ p[] d\btless sugge/$ to ,s]v9us ! possibility ( atta*+ a sail to a l& vehicle4 ,he made ! exp]im5t1 & 9 ! ye> #afjj con/ruct$ a sail+ c> :i*1 propell$ by ! w9d1 trav]s$ ! l& to a consid]able di/ance1 on "o occasion convey+ a company ( :i* ,pr9ce ,maurice ( ,orange 0 a memb]4 ,b 8 exp]im5ts h seldom be5 repeat$1 & inde$ _! lack ( practical feasibility sc>cely ne$s demon/ration4 ,! utility ( ! w9d1 h[ev]1 9 g5]at+ ! p[] 9 a /ation>y me*anism is famili> to ev]yone4 ,w9dmills 7 con/ruct$ at a comp>atively e>ly p]iod1 & not)/&+ all ! rec5t progress 9 ! developm5t ( /eam & electrical p[]1 ?is relatively primitive s-call$ prime mov] /ill holds its own 9 agricultural di/ricts1 p>ticul>ly 9 its application to pumps4 ,a w9dmill consi/s ( a s]ies ( incl9$ planes1 ea* ( :i* =ms "o ( ! radii ( a circle1 or spokes ( a :eel1 to ! axle ( :i* a ge>+ is adju/$ by :i* ! p[] g5]at$ is utiliz$4 ,! :eel is made to face ! w9d by ! w9d itself bl[+ aga9/ a sort ( rudd] :i* projects f ! axis4 ,! w9d bl[+ aga9/ ! incl9$ surfaces or vanes ( ! :eel causes ea* vane to move 9 accordance ) ! law ( compon5t =ces1 ?us revolv+ ! :eel z a :ole4 ,illu/ration3 ,,w9dmills ,,( ,,anci5t ,,& ,,mod]n ,,types4 ,! small] figures %[ ,dut* w9dmills ( ! pres5t day1 _m ( :i* are id5tical 9 /ructure ) ! w9dmills ( ! middle ages4 ,x w be se5 t ! sails c be furl$ :5 desir$ to put ! mill out ( op]ation4 ,9 ! mill ( mod]n type 7l>ge figure7 ! same effect is produc$ by slant+ ! slats ( ! :eel4 ,x has be5 affirm$ t ! ,romans _h w9dmills1 b ! sil5ce ( ,vitruvius1 ,s5eca1 & ,*ryso/om1 :o h spok5 ( ! advantages ( ! w9d1 makes ?is op9ion que/ionable4 ,x has be5 suppos$ by o!r writ]s t w9dmills 7 us$ 9 ,france 9 ! six? c5tury1 :ile /ill o!rs h ma9ta9$ t ?is me*anism 0 unkn[n 9 ,europe until ! "t ( ! ,crusades4 ,all t is tol]ably c]ta9 is t 9 ! twelf? c5tury w9dmills 7 9 use 9 ,france & ,engl&4 ,x is record$ t :5 !y began to be some:at common ,pope ,cele/9e ,,iii4 det]m9$ t ! ti!s ( !m belong$ to ! cl]gy4 ,,inh]5t ,,defects ,,( ,,! ,,w9dmill ,! m$ival ,european w9dmill 0 suppli$ ) great sails ( clo?1 & its picturesque appe>ance has be5 made famili> to ev]yone ?r\gh ! fam\s tale ( ,don ,quixote4 ,! mod]n w9dmill1 act+ on precisely ! same pr9ciple1 is a comp>atively small affair1 compris+ _m vanes ( metal1 & con/itut+ a f> m practical ma*9e4 ,! great defect ( all w9dmills1 h[ev]1 is f\nd 9 ! fact t ( necessity !y furni% su* v>iable p[]1 s9ce ! =ce ( ! w9d is incessantly *ang+4 ,wor/ ( all1 !re may be protract$ p]iods ( atmosph]ic calm1 dur+ :i*1 ( c\rse1 ! w9dmill ceases to h any utility :atev]4 ,?is in]adicable defect relegates ! w9dmill to a subord9ate place among prime mov]s1 yet on ! o!r h&1 its *eapness insures its employm5t = a long "t to come1 & ! indu/ry ( manufactur+ w9dmills cont9ues to be an important "o1 p>ticul>ly 9 ! ,unit$ ,/ates4 ,,runn+ ,,wat] ,! aggregate am\nt ( "w accompli%$ ) ! aid ( ! w9d is b trifl+1 comp>$ ) t :i* is accompli%$ ) ! aid ( wat]4 ,! supply ( wat] is practically inexhau/ible1 & ?is fluid be+ mu* m manageable ?an air1 c be made a f> m dep5dable aid to ! work]4 ,e /ream1 :atev] its rate ( fl[1 repres5ts an enorm\s /ore ( pot5tial en]gy4 ,a cubic foot ( wat] weighs ab\t sixty-two & a half p\nds4 ,! work+ capacity ( any mass ( wat] is repres5t$ by "o-half its weight into ! squ>e ( its velocity2 or1 /at$ o!rwise1 by its weight into ! di/ance ( its fall4 ,n[1 s9ce ! int]iors ( ! cont95ts1 :]e riv]s f9d _! s\rces1 are (t5 elevat$ by "s hundr$s or ev5 ?\s&s ( feet1 x foll[s t ! work+ en]gy exp5d$--& = ! mo/ "p wa/$--by ! aggregate wat] curr5t ( ! _w is beyond all calculation4 ,meantime1 h[ev]1 a portion ( ! en]gy :i* 9 ! aggregate repres5ts an enorm\s work+ p[] is utiliz$ ) ! aid ( v>i\s types ( wat] :eels4 ,wat]mills appe> to h be5 introduc$ 9 ! "t ( ,mi?ridates1 ,julius ,cs>1 & ,cic]o4 ,/rabo in=ms u t !re 0 a wat]mill ne> ! resid5ce ( ,mi?ridates2 & we le>n f ,pomponius ,sab9us1 t ! fir/ mill se5 at ,rome 0 erect$ on ! ,tib]1 a little be=e ! "t ( ,augu/us4 ,t !y exi/$ 9 ! "t ( ,augu/us is obvi\s f ! description giv5 ( !m by ,vitruvius1 & ! epigram ( ,antipat]1 :o is suppos$ to h liv$ 9 ! "t ( ,cic]o4 ,b ?\gh mills driv5 by wat] 7 introduc$ at ?is e>ly p]iod1 yet public mills did n appe> till ! "t ( ,honorius & ,arcadius4 ,!y 7 erect$ on ?ree canals1 :i* convey$ wat] to ! city1 & ! great] numb] ( !m lay "u ,m\nt ,janiculum4 ,:5 ! ,go?s besieg$ ,rome 9 #ecf1 & /opp$ ! l>ge aqu$uct & consequ5tly ! mills1 ,belis>ius appe>s to h con/ruct$1 = ! fir/ "t1 float+ mills ^u ! ,tib]4 ,mills driv5 by ! tide exi/$ at ,v5ice 9 ! ye> #ajdf1 or at lea/ 9 #ajgh4 ,! old] types ( wat] :eel are exce$+ly simple 9 con/ruction1 consi/+ m]ely ( v]tical :eels revolv+ on horizontal axes1 & s plac$ z to receive ! weight or pressure ( ! wat] on paddles or buckets at _! circumf]5ce4 ,! wat] might be all[$ to ru% "u ! :eel1 ?us con/itut+ an "u-%ot :eel2 or m commonly x fl[s f above1 con/itut+ an ov]-%ot :eel4 ,:]e ! natural fall is n available1 dams are employ$ to supply an artificial fall4 ,?is primitive type ( wat] :eel has be5 practically ab&on$ )9 ! la/ g5]ation1 its place hav+ be5 tak5 by ! mu* m effici5t type ( :eel kn[n z ! turb9e4 ,?is consi/s ( a :eel1 usually adju/$ on a v]tical axis1 & act+ on :at is virtually ! pr9ciple ( a w9dmill4 ,to ga9 a m5tal picture ( ! turb9e 9 its simple/ =m1 "o might imag9e ! propell+ screw ( a /eam%ip1 plac$ horizontally 9 a tube1 s t ! wat] c\ld ru% aga9/ its blades4 ,! t9y w9dmills :i* *ildr5 (t5 make by twi/+ pieces ( pap] illu/rate ! same pr9ciple4 ,( c\rse1 9 its develop$ =m ! turb9e is some:at elaborat$1 9 ! aim to utilize z l>ge a proportion ( ! en]gy ( ! fall+ wat] z is possible2 b ! pr9ciple rema9s ! same4 ,! turb9e :eel 0 inv5t$ by a ,fr5*man nam$ ,f\rneyron1 ab\t ?ree-qu>t]s ( a c5tury ago 7#ahbg71 b its great popul>ity1 9 ,am]ica 9 p>ticul>1 is a matt] ( ! la/ tw5ty or ?irty ye>s4 ,to-day x has virtually supplant$ e o!r type ( wat] :eel4 ,to use any o!r is inde$ a wa/eful extravagance1 z ! p]fect$ turb9e makes available m ?an eighty p] c5t4 ( ! k9etic en]gy ( any mass ( fall+ wat]4 ,a turb9e :eel two feet 9 diamet] is able to d ! "w ( an enorm\s :eel ( ! old type4 ,turb9e :eels are ( sev]al types1 "o op]at+ 9 a clos$ tube to :i* air has no access1 & ano!r 9 an op5 space 9 ! pres5ce ( air4 ,! wat] may also be made to ent] ! turb9e at ! side or f bel[1 ?us s]v+ to support ! weight ( ! me*anism--a consid]ation ( great importance 9 ! case ( su* gigantic turb9es z ^? t are employ$ at ,niag>a ,falls1 :i* we %all h occasion to exam9e 9 detail 9 a lat] *apt]4 ,illu/ration3 ,,wat] ,,:eels4 ,fig4 #a %[s a model ( ! s-call$ brea/ :eel1 a famili> type ( wat] :eel t has be5 9 use s9ce ! "t ( ! ,romans4 ,figs4 #b & #c %[ simil> :eels z us$ to-day 9 ,belgium4 ,fig4 #d %[s a model ( ,f\rneyron's turb9e4 ,?is :eel 0 made 9 #ahcg1 b ! orig9al turb9e 0 introduc$ by ,f\rneyron 9 #ahbg4 ,! turb9e :eel has n[ almo/ supplant$ ! o!r =ms ( wat] :eel except 9 rural di/ricts4 ,! p[] g5]at$ by a revolution ( ! turb9e :eel may1 ( c\rse1 be utiliz$ directly by belts or ge>+s atta*$ to its axle1 or x may be transf]r$ to a di/ance1 ) ! aid ( a dynamo g5]at+ electricity4 ,! latt] possibility1 :i* has only rec5tly be5 develop$1 & :i* we %all h occasion to exam9e 9 detail 9 connection ) our /udies ( ! p[] at ,niag>a1 gives a new field ( usefulness to ! turb9e :eel1 & makes x probable t ?is =m ( p[] w be va/ly m us$ 9 ! future ?an x has be5 9 ! pa/4 ,inde$1 x w\ld n be surpris+ 7 x ultimately to become ! prime s\rce ( work+ en]gy z utiliz$ 9 e dep>tm5t ( ! _w's "w4 ,mr4 ,edw>d ,h4 ,sanborn1 9 an article on ,motive ,p[] ,appliances 9 ! ,twelf? ,c5sus ,report ( ! ,unit$ ,/ates1 comm5ts ^u ! rec5t advances 9 ! use ( wat] :eels z foll[s3 ,"o notable advance 9 turb9e con/ruction has be5 ! production ( a type ( :eel especially design$ = op]at+ "u mu* high] heads ( wat] ?an 7 =m]ly consid]$ feasible = :eels ( ?is type4 ,turb9es are n[ built = heads rang+ f #ajj to #a1bjj feet1 & q a numb] ( :eels are 9 op]ation "u heads ( f #ajj to #bjj feet4 ,?is is an encroa*m5t ^u ! field occupi$ almo/ exclusively by :eels v>i\sly kn[n z ! 'impulse1' 'impact1' 'tang5tial1' or 'jet' type1 ! pr9ciple ( :i* is ! impact ( a p[]ful jet ( wat] f a small nozzle ^u a s]ies ( buckets m\nt$ ^u ! p]iph]y ( a small :eel4 ,! impact wat] :eel1 ,mr4 ,sanborn cont9ues1 has come l>gely into use dur+ ! la/ t5 ye>s1 pr9cipally 9 ! f> ,we/1 :]e high] heads ( wat] are available ?an c be f\nd 9 o!r p>ts ( ! c\ntry4 ,) :eels ( ?is type1 exce$+ly simple 9 con/ruction & ( comp>atively small co/1 a l>ge am\nt ( p[] is develop$ ) great economy "u ! great heads t are available4 ,) ! trem5d\s wat] pressure develop$ by heads ( #a1jjj feet & upw>d1 :i* 9 _m cases are us$ = ?is purpose1 :eels ( small diamet] develop an extraord9>y am\nt ( p[]4 ,to ! orig9al type ( impact :eel :i* fir/ l$ ! field h be5 add$ sev]al /yles embody+ practically ! same pr9ciple4 ,consid]able /udy has be5 giv5 to ! design+ ( buckets ) a view to secur+ free dis*>ge & ! avoidance ( any di/urb+ eddies1 & important improvem5ts h result$ f ! ?or\gh inve/igation ( ! action ( ! wat] dur+1 & subsequ5t to1 its impact on ! buckets4 ,! impact :eel has be5 adapt$ to a wide range ( s]vice ) great v>iation z to ! conditions "u :i* x op]ates1 :eels hav+ be5 made 9 ,cali=nia f #cj in*es to #cj feet 9 diamet]1 & to "w "u heads rang+ f #ce to #b1ajj feet1 & at spe$s rang+ f #fe to #a1ajj revolutions p] m9ute4 ,a numb] ( :eels ( ?is type h be5 built ) capacities ( n less ?an #a1jjj horse-p[] ea*4 ,,hydraulic ,,p[] ,a few words %\ld be said ab\t ! famili> me?od ( transmitt+ p[] ) ! aid ( wat]1 z illu/rat$ by ! hydro/atic press4 ,?is does n inde$ utilize ! en]gy ( ! wat] itself1 b x enables ! work] to transmit en]gy suppli$ f )\t1 & to ga9 an indef9ite p[] to move weights ?r\gh a %ort di/ance1 ) ! exp5diture ( v little work+ en]gy4 ,! pr9ciple on :i* ! hydro/atic press is bas$ is ! "o :i* 0 famili> to ! anci5t philosoph]s "u ! "n ( ! hydro/atic p>adox4 ,x 0 obs]v$ t if a tube is connect$ ) a clos$ receptacle1 su* z a /rong cask1 & cask & tube are fill$ ) wat]1 ! cask w pres5tly be bur/ by ! pressure ( ! wat]1 provid$ ! tube is rais$ to a height1 ev5 ?\gh ! actual weight ( wat] 9 ! tube be comp>atively slight4 ,a p[]ful cask1 = example1 may be bur/ by ! wat] p\r$ into a sl5d] pipe4 ,! result seems inde$ p>adoxical1 & = a long "t no explanation ( x 0 =?com+4 ,x rema9$ = ,s]v9us1 ^: horseless wagon is else:]e notic$1 to discov] t ! wat] at any giv5 level presses equally 9 all directions1 & t its pressure is proportionate to its dep?1 q reg>dless ( its bulk4 ,!n1 suppos+ ! tube 9 our exp]im5t to h a cross-section ( "o squ>e in*1 a pressure equal to t 9 ! tube w\ld be transmitt$ to ea* squ>e in* ( ! surface ( ! cask2 & ! pressure might ?us become enorm\s4 ,if1 in/ead ( a tube lift$ to a height1 ! same tube is connect$ ) a =ce pump op]at$ ) a lev]--an app>atus simil> to ! fire-eng9e ( ,ctesibius--x is obvi\s t precisely ! same effect may be produc$2 :atev] pressure is develop$ 9 ! pi/on ( ! =ce pump1 simil> pressure w be transf]r$ to a correspond+ area 9 ! surface ( ! cask or receptacle ) :i* ! =ce pump connects4 ,9 practise ?is pr9ciple is utiliz$1 :]e great pressure is desir$1 by mak+ a receptacle ) an enorm\s pi/on connect+ ) ! =ce pump j describ$4 ,an indef9ite p[] may ?us be develop$1 ! app>atus con/itut+ virtually a gigantic lev]4 ,b ! pr9ciple ( ! equival5ce ( weight & di/ance /ill holds1 precisely z 9 an actual lev]1 & :ile ! pressure t may be ex]t$ ) slight exp5diture ( en]gy is enorm\s1 ! di/ance ?r\gh :i* ?is pressure acts is correspond+ly small4 ,if1 = example1 ! pi/on ( ! =ce pump has an area ( "o squ>e in*1 :ile ! pi/on ( ! press has an area ( sev]al squ>e feet1 ! pressure ex]t$ w be measur$ 9 tons1 b ! di/ance ?r\gh :i* x is ex]t$ w be almo/ inf9itesimal4 ,! range ( utility ( ! hydro/atic press is1 !re=e1 limit$1 b )9 its sph]e1 x is an incomp>able transmitt] ( en]gy4 ,illu/ration3 ,,hydraulic ,,press ,,& ,,hydraulic ,,cap/an4 ,! upp] figure %[s ,bramah's orig9al hydraulic pump & press1 n[ pres]v$ 9 ! ,s\? ,k5s+ton ,museum1 ,london4 ,! ma*9e 0 con/ruct$ 9 #agif by ,joseph ,bramah to demon/rate ! pr9ciple ( 8 hydraulic press4 ,! discrepancy 9 size betwe5 ! small lev] work$ by h& & ! enorm\s lev] c>ry+ a heavy weight gives a vivid impression ( ! ga9 9 p[] ?r\gh ! use ( ! app>atus4 ,! l[] figure %[s ! hydraulic cap/an us$ on _m mod]n %ips1 9 :i* ! same pr9ciple is utiliz$4 ,moreov]1 x is possible to rev]se ! action ( ! hydraulic app>atus s z to ga9 motion at ! exp5se ( p[]4 ,a famili> type ( elevator is a case 9 po9t4 ,! ess5tial feature ( ! hydraulic elevator consi/s ( a ram atta*$ to ! bottom ( ! elevator & ext5d+ d[n into a cyl9d]1 slightly long] ?an ! height to :i* ! elevator is to rise4 ,! ram is fitt+ into a cyl9d] ) wat]-tight pack+1 or a cut lea!r valve4 ,wat] "u high pressure is admitt$ to ! cyl9d] ?r\gh ! valve at ! bottom1 & ! pressure ?us suppli$ pu%es up ! ram1 c>ry+ ! elevator ) x1 ( c\rse4 ,ano!r valve all[s ! wat] to escape1 s t ram & elevator may desc5d1 too rapid desc5t be+ prev5t$ by ! p>tial balanc+ ( ram & elevator ) weights act+ ov] pulleys4 ,! ram1 to ! end ( :i* pressure is ?us appli$1 ne$ be b a few in*es 9 diamet]4 ,wat] pressure is secur$ by br++ wat] f an elevation4 ,su* an elevator acts sl[ly1 b is a v safe & 9 _m ways satisfactory me*anism4 ,su* elevators are /ill us$ ext5sively 9 ,europe1 b h be5 almo/ altoge!r displac$ 9 ,am]ica by ! electric elevator4 ,! hydraulic elevator j describ$ is virtually a wat] eng9e1 ! ram act+ z pi/on4 ,a v]itable eng9e1 ( small size1 to p]=m any species ( me*anical "w1 may be con/ruct$ on precisely ! same pr9ciple1 ! pi/on 9 ?is case act+ 9 a cyl9d] simil> to t ( ! ord9>y /eam eng9e4 ,su* an eng9e op]ates sl[ly b ) great p[]4 ,x has special utility :]e x is desirable to apply p[] int]mitt5tly1 z 9 v>i\s p>ts ( a docky>d1 or 9 h&l+ guns & ammunition on %ipbo>d4 ,9 ! =m] case 9 p>ticul>1 x is (t5 inconv5i5t to use /eam p[]1 z /eam s5t f a c5tral boil] cond5ses 9 a way to int]f]e ) its op]ation4 ,9 su* a case any numb] ( small wat]-pressure eng9es may be op]at$ f a s+le tank :]e wat] is at a high elevation1 or :]e ! requisite pressure is secur$ artificially4 ,9 ! latt] case1 ! wat] is kept "u pressure by a l>ge pi/on or ram heavily weight$1 ! entire receptacle be+1 ( c\rse1 ( wat]-tight con/ruction & adapt$ to )/& pressure4 ,! pump t supplies ! tank is ord9>ily made to "w automatically1 ceas+ op]ation z soon z ! ram rises to ! top ( ! receptacle1 & beg9n+ aga9 :5ev]1 ?r\gh use ( wat]1 ! ram beg9s to desc5d4 ,su* an app>atus is call$ an accumulator4 ,su* wat] eng9es h come into vogue only 9 comp>atively rec5t times1 be+ sugge/$ by ! /eam eng9e4 ,z already po9t$ out1 _! utility is re/rict$1 yet ! total numb] ( !m 9 actual use to-day is l>ge1 & _! %>e 9 ! _w's "w is n altoge!r inconsid]able4 ,v ,,captive ,,molecules3 ,,! ,,/ory ,,( ,,! ,,/eam ,,eng9e ,we come n[ to t all-important trans=m] ( p[]1 ! /eam eng9e4 ,ev]ybody kn[s t /eam is a /ate ( wat] 9 :i*1 "u ! influ5ce ( heat1 ! molecules h brok5 away f ! mutual attraction ( cohesion1 & are fly+ ab\t at inconceivable spe$1 reb\nd+ f "o ano!r aft] collision1 9 virtue ( _! ela/icity1 ex]t+ 9 ! aggregate an enorm\s pressure 9 e direction4 ,x is ?is consid]ation ( ! intimate "* ( /eam t ju/ifies ! title ( ! pres5t *apt]2 a title t has fur!r utility z draw+ a contra/ betwe5 ! mann] ( work+ ) :i* we are n[ to be conc]n$1 & ! v>i\s types ( work]s t we h previ\sly consid]$4 ,9 speak+ ( ! animal ma*9e & ( "w accompli%$ by ! air & ! wat]1 we h be5 conc]n$ prim>ily ) masses ( matt]1 possess+ & transmitt+ en]gy4 ,( c\rse molecules--s9ce !y make up ! sub/ance ( all matt]--c\ld n be altoge!r ignor$1 b 9 ! ma9 we h _h to d ) mol> r ?an ) molecul> motion4 ,n[1 h[ev]1 we are conc]n$ ) a me*anism 9 :i* ! molecul> activities are directly conc]n$ 9 p]=m+ "w4 ,ev5 9 ! aggregate ! molecules make up a m]e intangible gas1 :i* requires to be closely conf9$ 9 ord] t its en]gy may be made available4 ,once ! molecules h p]=m$ _! "w1 !y are s *ang$ 9 _! activities t !y s9k back1 z x 71 exhau/$1 into a relatively quiesc5t /ate1 :i* enables _! lat5t cohesive =ces to r$uce !m aga9 to ! /ate ( a liquid4 ,9 a ^w1 we are conc]n$ ) ! manife/ation ( en]gy :i* dep5ds ^u molecul> activities 9 a way q diff]5t f :at has be5 ! case ) any ( ! previ\sly consid]$ me*anisms4 ,! tangible manife/ation ( en]gy :i* we t]m heat is n m]ely a condition ( action & a by-product1 z x 0 9 ! case ( ! animal ma*9e2 x is ! ess5tial factor ^u :i* all ! effici5cy ( ! me*anism dep5ds4 ,x %\ld p]haps be /at$ t ?is explanation ( ! action ( ! /eam eng9e is a comp>atively mod]n sci5tific int]pretation4 ,! e>li] exp]im5t]s br\ght ! /eam eng9e to a high /ate ( effici5cy1 )\t hav+ any su* conception z ?is ( ! nature ( /eam itself4 ,= practical purposes x suffices to note t wat] :5 heat$ takes ! =m ( /eam2 t ?is /eam has ! prop]ty ( p[]ful & indef9ite expansion2 & ?irdly1 t :5 all[$ to escape f a /ate ( pressure1 sudd5 expansion ( ! /eam cools x suffici5tly to cause ! recond5sation ( "p ( its sub/ance1 ?us creat+ a vacuum4 ,/at$ 9 few words1 ! entire action ( ! /eam dep5ds ^u ^! simple me*anical pr9ciples4 ,! pr9ciples are practically appli$ by p]mitt+ ! /eam to ent] ! cyl9d] :]e x c act on a pi/on1 to :i* x gives ! ?ru/ t is transmitt$ to an ext]nal me*anism by means ( a rod atta*$ to ! pi/on4 ,:5 ! pi/on has be5 driv5 to ! end ( ! desir$ ?ru/1 ! valve is op5$ automatically1 p]mitt+ ! /eam to escape1 ?us produc+ a vacuum1 & insur+ ! return ?ru/ ( ! pi/on1 :i* is fur!r facilitat$1 ord9>ily1 by ! admission ( /eam to ! o!r side ( ! pi/on4 ,practical op]ation ( ?is me*anism is famili> to ev]yone1 ?\gh ! m>vel ( its p[] & effici5cy seems none ! less because ( its famili>ity4 ,x is n too mu* to say t ?is relatively simple device1 9 its fir/ g5]al application1 m>k$ "o ( ! mo/ important turn+ po9ts 9 ! hi/ory ( civilization4 ,to its influ5ce1 m ?an to any o!r s+le cause1 mu/ be ascrib$ ! revolution>y *ange t came ov] ! "* ( practical life 9 ! n9ete5? c5tury4 ,f prehi/oric times till well t[>d ! close ( ! eighte5? c5tury1 !re 0 sc>cely any important *ange 9 c>ry+ out ! _w's "w4 ,& 9 ! few g5]ations t h s9ce elaps$1 ! entire aspect ( ! me*anical _w has be5 *ang$1 ! work+ effici5cy ( ! individual has be5 l>gely increas$2 me*anical tasks h become easy :i* hi!rto 7 sc>cely )9 ! range ( human capacity4 ,be=e we g on to ! detail$ /udy ( ! ma*9e :i* has produc$ ^! rem>kable results1 x is desirable to make inquiry z to ! hi/orical developm5t ( s important an inv5tion4 ,! practical /eam eng9e 9 its mod]n =m dates1 z j m5tion$1 f ! latt] "p ( ! eighte5? c5tury1 & 0 p]fect$ by ,james ,watt1 :o is commonly ?\ght ( z be+ its inv5tor4 ,9 po9t ( fact1 h[ev]1 ! hi/ory ( mo/ inv5tions is duplicat$ "h1 z on exam9ation x appe>s t v>i\s =]unn]s ( ,watt _h be5 on ! track ( ! /eam eng9e1 & "s ( !m1 inde$1 _h produc$ a workable ma*9e ( no small degree ( effici5cy4 ,! v e>lie/ exp]im5ts 7 made away back 9 ! ,alex&rian days 9 ! second c5tury be=e ! ,*ri/ian era1 ! exp]im5t] be+ ! fam\s ,h]o1 ^: "w 9 an alli$ field 0 ref]r$ to 9 ! prec$+ *apt]4 ,h]o produc$--or at lea/ describ$ & s is cr$it$ ) produc+1 ?\gh ! actual inv5tor may h be5 ,ctesibius--a little toy me*anism1 9 :i* a holl[ ball 0 made to revolve on an axis ?r\gh ! ag5cy ( /eam1 :i* escap$ f two b5t tubes plac$ on opposite sides ( ! ball1 _! orifices po9t+ 9 opposite directions4 ,! app>atus _h no practical utility1 b x suffic$ to e/abli% ! pr9ciple t heat1 act+ ?r\gh ! ag5cy ( /eam1 c\ld be made to d me*anical "w4 ,_h n ! age ( ,h]o be5 a "t ( m5tal /asis1 x is highly probable t ! pr9ciple he _h ?us demon/rat$ w\ld h be5 appli$ to "s m practical me*anism 9 succe$+ g5]ations4 ,z x 01 h[ev]1 no?+ practical came ( 8 exp]im5t1 & ! /eam turb9e eng9e 0 rememb]$ only z a sci5tific toy4 ,no o!r work] cont9u$ ! exp]im5ts1 s f> z is kn[n1 until ! "t ( ! great ,italian1 ,leon>do da ,v9ci1 :o1 late 9 ! fifte5? c5tury1 gave a new impulse to me*anical inv5tion4 ,leon>do exp]im5t$ ) /eam1 & succe$$ 9 produc+ :at 0 virtually an explosion eng9e1 by ! ag5cy ( :i* a ball 0 propell$ along ! e>?4 ,b ?is exp]im5t also fail$ to h practical result4 ,,beg9n+s ,,( ,,mod]n ,,discov]y ,su* sporadic exp]im5ts z ^! h no sequ5tial connection ) ! /ory ( ! evolution ( ! /eam eng9e4 ,! exp]im5ts :i* l$ directly on to practical a*ievem5ts 7 n begun until ! sev5te5? c5tury4 ,9 ! v fir/ ye> ( t c5tury1 an ,italian nam$ ,giovanni ,batti/a della ,porta publi%$ a treatise on pneumatics1 9 :i* ! idea ( utiliz+ /eam = ! practical purpose ( rais+ wat] 0 expressly /at$4 ,! idea ( ?is inv5tor 0 put into effect 9 #afbd by a ,fr5* eng9e] & ma!matician1 ,solomon de ,caus4 ,he inv5t$ two diff]5t ma*9es1 ! fir/ ( :i* requir$ a sph]ical boil] hav+ an int]nal tube rea*+ ne>ly to ! bottom2 a fire b5ea? ! boil] produc$ /eam :i* w\ld =ce ! wat] 9 ! boil] to a height proportional to ! pressure obta9$4 ,9 ! o!r ma*9e1 /eam is l$ f ! boil] into ! upp] "p ( a clos$ ci/]n conta9+ wat] to be elevat$4 ,to ! l[] portion ( ! ci/]n a deliv]y pipe 0 atta*$ s t wat] 0 dis*>g$ "u a consid]able pressure4 ,?is arrangem5t 0 precisely simil> to ! app>atus employ$ by ,h]o ( ,alex&ria 9 v>i\s ( 8 f\nta9s1 z reg>ds ! pr9ciple ( exp&+ gas to propel wat]4 ,an important diff]5ce1 h[ev]1 consi/s 9 ! fact t ! s*eme ( della ,porta & ( de ,caus embodi$ ! idea ( g5]at+ pressure ) ! aid ( /eam1 :]eas ,h]o _h dep5d$ m]ely on ! expansive prop]ty ( air compress$ by ! wat] itself4 ,:ile ^! me*anisms conta9$ ! g]m ( an idea ( va/ importance1 ! me*anisms !mselves 7 ( trivial utility4 ,x is n ev5 cle> :e!r _! projectors _h an idea ( ! prop]ties ( ! cond5sation ( vapor1 ^u :i* ! work+ ( ! practical /eam eng9e s l>gely dep5ds4 ,?is idea1 h[ev]1 0 probably grasp$ ab\t half a c5tury lat] by an ,engli%man1 ,edw>d ,som]set1 ! celebrat$ ,m>quis ( ,worce/]1 :o 9 #affc describ$ 9 8 ,c5tury ( ,inv5tions an app>atus = rais+ wat] by ! expansive =ce ( /eam4 ,8 own acc\nt ( 8 inv5tion is z foll[s3 ,an admirable & mo/ =cible way to drive up wat] by fire2 n by draw+ or suck+ x upw>ds1 = t mu/ be z ! philosoph] calle? x1 intra sphram activitatis1 :i* is b at su* a di/ance4 ,b ?is way ha? no b\nd]1 if ! vessel be /rong en\gh3 = ,i h tak5 a piece ( :ole cannon1 :]e( ! end 0 bur/1 & fill$ x ?ree-qu>t]s full ( wat]1 /opp+ & screw+ up ! brok5 end1 z also ! t\*-hole2 & mak+ a con/ant fire "u x1 )9 tw5ty-f\r h\rs x bur/ & made a great crack2 s t hav+ a way to make my vessels s t !y are /r5g!n$ by ! =ce )9 !m1 & ! "o to fill aft] ! o!r1 ,i h se5 ! wat] run l a con/ant /ream1 =ty feet high3 "o vessel ( wat]1 r>efi$ by fire1 drive? up =ty ( cold wat]2 & ! man t t5ds ! "w is b to turn two cocks1 t "o vessel ( wat] be+ consum$1 ano!r beg9s to =ce & refill ) cold wat]1 & s successively2 ! fire be+ t5d$ & kept con/ant1 :i* ! self-same p]son may likewise abundantly p]=m 9 ! int]im1 betwe5 ! necessity ( turn+ ! said cocks4 ,x is un=tunate t ! ,m>quis did n give a m elaborate description ( ?is rem>kable contrivance4 ,! fact t he treats x s casually is suffici5t evid5ce t he _h no conception ( ! possibilities ( ! me*anism2 b1 on ! o!r h&1 8 description suffices to prove t he _h ga9$ a cle> notion (1 & _h exp]im5tally demon/rat$1 ! trem5d\s p[] ( expansion t resides 9 /eam4 ,no example ( 8 /eam pump has be5 pres]v$1 & hi/orians ( ! subject h be5 left 9 d\bt z to "s details ( its con/ruction1 & 9 p>ticul> z to :e!r x utiliz$ ! pr9ciple ( a vacuum creat$ ?r\gh cond5sation ( ! /eam4 ,,?omas ,,sav]y',s ,,/eam ,,pump ,?is pr9ciple 0 cle>ly grasp$1 h[ev]1 by ano!r ,engli%man1 ,?omas ,sav]y1 a ,corni% m9e capta91 :o 9 #afih secur$ a pat5t = a /eam eng9e to be appli$ to ! rais+ ( wat]1 etc4 ,a work+ model ( ?is ma*9e 0 produc$ be=e ! ,royal ,society 9 #afii4 ,! transactions ( ! ,society conta9 ! foll[+3 ,june #ad?1 #afii1 ,mr4 ,sav]y ent]ta9$ ! ,royal ,society ) %[+ a small model ( 8 eng9e = rais+ wat] by help ( fire1 :i* he set to "w be=e !m3 ! exp]im5t succe$$ accord+ to expectation1 & to _! satisfaction4 ,! foll[+ v cle> description ( ,sav]y's eng9e is giv5 9 ! introduction to ,beckmann's ,hi/ory ( ,inv5tions3 ,?is eng9e1 :i* 0 us$ = "s "t to a consid]able ext5t = rais+ wat] f m9es1 consi/$ ( a /rong iron vessel %ap$ l an egg1 ) a tube or pipe at ! bottom1 :i* desc5d$ to ! place f :i* ! wat] 0 to be drawn1 & ano!r at ! top1 :i* asc5d$ to ! place to :i* x 0 to be elevat$4 ,?is oval vessel 0 fill$ ) /eam suppli$ f a boil]1 by :i* ! atmosph]ic air 0 fir/ bl[n out ( x4 ,:5 ! air 0 ?us expell$ & no?+ b pure /eam left 9 ! vessel1 ! communication ) ! boil] 0 cut (f1 & cold wat] p\r$ on ! ext]nal surface4 ,! /eam )9 0 ?us cond5s$ & a vacuum produc$1 & ! wat] drawn up f bel[ 9 ! usual way by suction4 ,! oval vessel 0 ?us fill$ ) wat]2 a cock plac$ at ! bottom ( ! l[] pipe 0 !n clos$1 & /eam 0 introduc$ f ! boil] into ! oval vessel above ! surface ( ! wat]4 ,?is /eam be+ ( high pressure1 =c$ ! wat] up ! asc5d+ tube1 f ! top ( :i* x 0 dis*>g$1 & ! oval vessel be+ ?us refill$ ) /eam1 ! vacuum 0 aga9 produc$ by cond5sation1 & ! same process 0 repeat$4 ,by us+ two oval /eam vessels1 :i* w\ld act alt]nately--"o draw+ wat] f bel[1 :ile ! o!r 0 =c+ x upw>ds1 an un9t]rupt$ dis*>ge ( wat] 0 produc$4 ,ow+ to ! dang] ( explosion1 f ! high pressure ( ! /eam :i* 0 us$1 & f ! enorm\s wa/e ( heat by unnecess>y cond5sation1 ^! eng9es soon fell into disuse4 ,illu/ration3 ,,?omas ,,sav]y',s ,,/eam ,,eng9e4 ,! pr9ciple involv$ is t ( ! expansion ( /eam ex]t+ a propulsive =ce & its subsequ5t cond5sation to produce a vacuum4 ,^! are ! pr9ciples employ$ 9 ! mod]n /eam eng9e1 b ! only use to :i* !y 7 put 9 ,sav]y's eng9e 0 ! elevation ( wat] by suction4 ,?is description makes x obvi\s t ,sav]y _h ! cle>e/ conception ( ! production ( a vacuum by ! cond5sation ( /eam1 & ( ! utilization ( ! suction ?us e/abli%$ 7:i* suction1 z we "k1 is really due to ! pressure ( outside air7 to accompli% useful "w4 ,sav]y also arrang$ ?is app>atus 9 duplicate1 s t "o vessel 0 fill+ ) wat] :ile ! o!r 0 =c+ wat] to ! deliv]y pipe4 ,?is is cr$it$ ) be+ ! fir/ useful app>atus = rais+ wat] by ! combu/ion ( fuel4 ,!re 0 a great wa/e ( /eam1 ?r\gh imp>t+ heat to ! wat]1 b ! feasibility ( ! all-important pr9ciple ( accompli%+ me*anical labor ) ! aid ( heat 0 at la/ demon/rat$4 ,z yet1 h[ev]1 ! exp]im5t]s 7 n on ! track ( ! me?od by :i* p[] c\ld be advantage\sly transf]r$ to outside ma*9]y4 ,an ef=t 9 q ano!r direction to accompli% ?is _h be5 made z e>ly z #afbi by ,giovanni ,branca1 an ,italian ma!matician1 :o _h propos$ to obta9 rot>y motion by all[+ a jet ( /eam to bl[ aga9/ ! vanes ( a fan :eel1 capable ( turn+ on an axis4 ,9 o!r words1 he endeavor$ to utilize ! pr9ciple ( ! w9dmill1 ! /eam tak+ ! place ( mov+ air4 ,! idea is ( c\rse p]fectly feasible1 be+ inde$ virtually t :i* is employ$ 9 ! mod]n /eam turb9e2 b to put ! idea into practise requires special detail$ arrangem5ts ( /eam jet & vanes1 :i* x is n /range ! e>ly inv5tor fail$ to discov]4 ,8 exp]im5ts appe> n to h be5 foll[$ up by any imm$iate successor1 & no?+ practical came ( !m1 nor 0 ! pr9ciple :i* he _h attempt$ to utilize made available until long aft] a =m ( /eam eng9e utiliz+ ano!r pr9ciple = ! transmission ( p[] _h be5 p]fect$4 ,,d5is ,,pap9 ,,inv5ts ,,! ,,pi/on ,,eng9e ,! pr9ciple 9 "q 0 t ( caus+ exp&+ /eam to press aga9/ a pi/on work+ tightly 9 a cyl9d]1 a pr9ciple1 9 %ort1 ) :i* ev]yone is famili> n[adays ?r\gh its utilization 9 ! ord9>y /eam eng9e4 ,! idea ( mak+ use ( su* a pi/on appe>s to h orig9at$ ) a ,fr5*man1 ,d5is ,pap91 a sci5tific work]1 :o1 be+ bani%$ f 8 own c\ntry1 0 e/abli%$ z pr(essor ( ma!matics at ! ,univ]sity ( ,m>burg4 ,he conceiv$ ! important idea ( transmitt+ p[] by means ( a pi/on z e>ly z #afhh1 & ab\t two ye>s lat] add$ ! idea ( produc+ a vacuum 9 a cyl9d]1 by cool+ ! cyl9d]1--! latt] idea be+1 z we h j se51 ! "o :i* ,sav]y put into effect4 ,illu/ration3 ,,diagrams ,,( ,,e>ly ,,attempts ,,to ,,utilize ,,! ,,p[] ,,( ,,/eam4 ,,giovanni ,,branca #afbi ,,guillaume ,,amontons #afii ,two attempts to give rotation to a me*anical app>atus ?r\gh ! action ( heat$ air or /eam4 ,no?+ practical came ( ei!r ef=t1 b ! me*anisms depict$ are ( hi/orical int]e/4 ,x w be not$ t ,pap9's inv5tion ant$at$ t ( ,sav]y2 to ! ,fr5*man1 !re=e1 mu/ be giv5 ! cr$it ( hitt+ ^u two important pr9ciples :i* made feasible ! mod]n /eam eng9e4 ,pap9 con/ruct$ a model consi/+ ( a small cyl9d] 9 :i* a solid pi/on work$4 ,9 ! cyl9d] b5ea? ! pi/on 0 plac$ a small quantity ( wat]1 :i*1 :5 ! cyl9d] 0 heat$1 0 turn$ into /eam1 ! ela/ic =ce ( :i* rais$ ! pi/on4 ,! cyl9d] 0 !n cool$ by remov+ ! fire1 :5 ! /eam cond5s$1 ?us creat+ a vacuum 9 ! cyl9d]1 into :i* ! pi/on 0 =c$ by ! pressure ( ! atmosph]e4 ,su* an app>atus seems crude en\gh1 yet x incorporates ! ess5tial pr9ciples1 & requir$ b ! use ( +5uity 9 elaborat+ details ( ! me*anism1 to make a really effici5t /eam eng9e4 ,x w\ld appe>1 h[ev]1 t ,pap9 0 *iefly int]e/$ 9 ! !oretical1 r ?an 9 ! really practical side ( ! "q1 & !re is no evid5ce ( 8 hav+ produc$ a work+ ma*9e ( practical p[]1 until aft] su* ma*9es work$ by /eam _h be5 con/ruct$ else:]e4 ,,?omas ,,newcom5',s ,,improv$ ,,eng9e ,z has happ5$ s (t5 9 o!r fields1 ,engli%m5 7 ! fir/ to make practical use ( ! new ideas4 ,9 #agje ,?omas ,newcom51 a blacksmi? or ironmong]1 & ,john ,cawley1 a plumb] & glazi]1 pat5t$ _! atmosph]ic eng9e1 & five ye>s lat]1 9 ! ye> #agaj1 namely1 ,newcom5 _h on ! m>ket an eng9e :i* is describ$ 9 ! ,report ( ! ,dep>tm5t ( ,sci5ce & ,arts ( ! ,s\? ,k5s+ton ,museum1 z ! fir/ real pump+ eng9e ev] made4 ,! same report describes ! eng9e z a v]tical /eam cyl9d] provid$ ) a pi/on connect$ at "o end ( ! beam1 hav+ a pivot or be>+ 9 ! middle ( its l5g?1 & at ! o!r end ( ! beam pump rods = work+ ! pump4 ,! cyl9d] 0 surr\nd$ by a second cyl9d] or jacket1 op5 at ! top1 & cold wat] c\ld be suppli$ to ?is out] cyl9d] at pleasure4 ,! s+le or work+ cyl9d] c\ld be suppli$ ) /eam :5 desir$ f a boil] bel[ x4 ,!re 0 a dra9 pipe f ! bottom ( ! work+ cyl9d]1 & "o f ! out] cyl9d]4 ,= ! work+ ( ! eng9e /eam 0 admitt$ to ! work+ cyl9d]1 s z to fill x & expel all ! air1 ! pi/on !n be+ at ! top1 ow+ to ! weight ( ! pump rods be+ suffici5t to lift x2 !n ! /eam 0 %ut (f & ! dra9 cocks clos$ & cold wat] admitt$ to ! out] cyl9d]1 s t ! /eam 9 ! work+ cyl9d] cond5s$1 &1 leav+ a p>tial vacuum ( pressure ( ! atmosph]e1 =c$ ! pi/on d[n & drew up ! pump rods1 ?us mak+ a /roke ( ! pump4 ,!n ! wat] 0 drawn (f f ! out] cyl9d] & /eam admitt$ to ! work+ cyl9d] be=e all[+ ! pi/on to return to ! top ( its /roke1 ready = ! next d[n /roke4 ,x w be obs]v$ t ?is ma*9e adopts ! pr9ciple1 ) only a *ange ( me*anical details1 ( ! ,pap9 eng9e j describ$4 ,a lat] improvem5t made by ,newcom5 did away ) ! out] cyl9d] = cond5s+ ! /eam1 employ+ in/ead an injection ( cold wat] into ! work+ cyl9d] itself1 ?us enabl+ ! eng9e to "w m quickly4 ,x is said t ! sup]iority ( ! int]nal cond5s+ arrangem5t 0 accid5tally discov]$ ?r\gh ! improv$ work+ ( an eng9e t *anc$ to h an exceptionally leaky pi/on or cyl9d]4 ,_m eng9es 7 made on ?is plan & put into practical use4 ,ano!r important improvem5t 0 made by a connection f ! beam to ! cocks or valves1 s t ! eng9e work$ automatically1 :]eas 9 ! fir/ place x _h be5 necess>y to h a boy or man op]ate ! valves1--a mo/ awkw>d arrangem5t1 9 ! light ( mod]n improvem5ts4 ,z ! /ory is told1 ! duty ( op5+ & clos+ ! regulat+ & cond5s+ valves 0 intru/$ to boys call$ cock boys4 ,x is said t "o ( ^! boys nam$ ,humphrey ,pott] wi%+ to jo9 8 comrades at play )\t expos+ himself to ! consequ5ces ( susp5d+ ! p]=mance ( ! eng9e1 contriv$1 by atta*+ /r+s ( prop] l5g? to ! lev]s :i* gov]n$ ! two cocks1 to connect !m ) ! beam1 s t x %\ld op5 & close ! cocks z x mov$ up & d[n ) ! mo/ p]fect regul>ity4 ,?is /ory has pass$ curr5t = almo/ two c5turies1 & x has be5 us$ to po9t _m a useful moral4 ,x seems almo/ a pity to di/urb s int]e/+ a tradition1 yet x mu/ h occurr$ to m ?an "o iconocla/ t ! tale is almo/ too good to be true4 ,& some:at rec5tly x has be5 m ?an h9t$ t ,desaguli]s1 ) :om ! /ory orig9at$1 drew ^u 8 imag9ation = x4 ,a pr9t is 9 exi/5ce1 made s long ago z #agai1 repres5t+ an eng9e erect$ by ,newcom5 at ,dudley ,ca/le1 ,/af=d%ire1 9 #agab1 9 :i* an automatic valve ge> is cle>ly %[n1 prov+ t ! ,newcom5 eng9e 0 work$ automatically at ?is e>ly p]iod4 ,t ! admirable /ory ( ! inv5tive y\?1 ^: wits gave him leisure = play1 may n be altoge!r discr$it$1 h[ev]1 x %\ld be add$ t unque/ionably "s ( ! e>ly eng9es _h a h&-mov$ ge>1 & t at lea/ "o su* 0 /ill work+ 9 ,engl& aft] ! middle ( ! n9ete5? c5tury4 ,x seems probable1 !n1 t ! v fir/ eng9es 7 )\t ! automatic valve ge>1 & !re is no inh]5t reason :y a quick-witt$ y\? may n h be5 ! fir/ to discov] & rem$y ! defect4 ,accord+ to ! ,report ( ! ,dep>tm5t ( ,sci5ce & ,arts ( ! ,s\? ,k5s+ton ,museum3 ,! adoption ( ,newcom5's eng9e 0 rapid1 =1 comm5c+ 9 #agaa ) ! eng9e at ,wolv]hampton1 ( tw5ty-?ree in* diamet] & six foot /roke1 !y 7 9 common use 9 ,engli% colli]ies 9 #agbe2 & ,smeaton f\nd 9 #agfg t1 9 ! neighborhood ( ,newca/le alone !re 7 fifty-sev5 at "w1 rang+ 9 size f tw5ty-eight in* to sev5ty-five in* cyl9d] diamet]1 & giv+ collectively ab\t twelve hundr$ horse-p[]4 ,z ,newcom5 obta9$ an evaporation ( ne>ly eight p\nds ( wat] p] p\nd ( coal1 ! increase ( boil] effici5cy s9ce 8 "t has necess>ily be5 b slight1 al?\gh 9 o!r requisites ( ! /eam g5]ator great improvem5ts are noticeable4 ,illu/ration3 ,a ,,model ,,( ,,! ,,newcom5 ,,eng9e4 ,?is eng9e has p>ticul> int]e/ n only because x 0 a practical pump+ eng9e1 b also because x 0 :ile repair+ an eng9e ( ?is type t ,watt 0 l$ to ! exp]im5ts t result$ 9 8 epo*-mak+ discov]y4 ,,! ,,com+ ,,( ,,james ,,watt ,! ,newcom5 eng9e _h l[ work+ effici5cy z comp>$ ) ! mod]n eng9e2 nev]!less1 "s ( ^! eng9es are /ill us$ 9 a few colli]ies :]e wa/e coal is available1 ! pressure enabl+ ! /eam to be g5]at$ 9 boil]s unsafe = o!r purposes4 ,! great importance ( ! ,newcom5 eng9e1 h[ev]1 is hi/orical2 = x 0 :ile engag$ 9 repair+ a model ( "o ( ^! eng9es t ,james ,watt 0 l$ to inv5t 8 plan ( cond5s+ ! /eam1 n 9 ! work+ cyl9d] itself1 b 9 a sep>ate vessel1--! pr9ciple ^u :i* su* va/ improvem5ts 9 ! /eam eng9e 7 to dep5d4 ,x is impossible to ov]e/imate ! importance ( ! "w :i* ,watt accompli%$ 9 develop+ ! /eam eng9e4 ,fully to appreciate x1 we mu/ und]/& t up to ?is "t ! /eam eng9e _h a v limit$ sph]e ( usefulness4 ,! ,newcom5 eng9e repres5t$ ! mo/ develop$ =m1 z we h se52 & ?is1 l ! o!rs t x _h s l>gely sup]s$$1 0 employ$ solely = ! pump+ ( wat]4 ,9 ! ma91 its use 0 conf9$ to m9es1 :i* 7 (t5 r5d]$ unworkable because ( flood+4 ,we h already se5 t a consid]able numb] ( eng9es 7 9 use1 yet _! p[] 9 ! aggregate add$ b a trifle to man's work+ effici5cy1 & ! "w t !y did accompli% 0 done 9 a mo/ uneconomical mann]4 ,inde$ ! am\nt ( fuel requir$ 0 s great z to prohibit _! use 9 _m m9es1 :i* w\ld h be5 valuable c\ld a *eap] means h be5 f\nd ( free+ !m f wat]4 ,watt's inv5tions1 z we %all see1 accompli%$ ?is end1 z well z v>i\s o!rs t 7 n anticipat$4 ,x 0 ?r\gh consid]ation ( ! wa/eful mann] ( action ( ! /eam eng9e t ,watt 0 l$ to give att5tion to ! subject4 ,! great inv5tor 0 a "y man at ! ,univ]sity ( ,glasg[4 ,he _h previ\sly s]v$ an appr5tice%ip ( "o ye> ) a mak] ( philosophical in/rum5ts 9 ,london1 b ill heal? _h prev5t$ him f f9i%+ 8 appr5tice%ip1 & he _h !re=e be5 prohibit$ f practis+ 8 w\ld-be pr(ession 9 ,glasg[4 ,f9ally1 h[ev]1 he _h be5 p]mitt$ to "w "u ! auspices ( ! ,univ]sity2 & 9 due c\rse1 z a "p ( 8 (ficial duties1 he 0 engag$ 9 repair+ a model ( ! ,newcom5 eng9e4 ,?is incid5t is usually m5tion$ z hav+ det]m9$ ! l9e ( ,watt's future activity4 ,x %\ld be recall$1 h[ev]1 t ,watt _h become a p]sonal fri5d ( ! celebrat$ ,pr(essor ,black1 ! discov]] ( lat5t heat1 & ! =emo/ au?ority 9 ! _w1 9 ?is p]iod1 on ! /udy ( pneumatics4 ,j :at %>e ,black _h 9 develop+ ,watt's idea1 or 9 direct+ 8 /udies t[>d ! expansive prop]ties ( /eam1 x w\ld p]haps be difficult to say4 ,x is kn[n1 h[ev]1 t ! subject 0 (t5 "u discussion2 & ! int]e/ ev9c$ 9 x by ,black is %[n by ! fact t he subsequ5tly wrote a hi/ory ( ,watt's inv5tions4 ,x is nev] possible1 p]haps1 = ev5 ! inv5tor himself to re-live ! hi/ory ( ! gr[? ( an idea 9 8 own m9d4 ,mu* less is x possible = him to say precisely :at %>e ( 8 progress has be5 due to *ance sugge/ions ( o!rs4 ,b x is int]e/+1 at lea/1 to recall ?is association ( ,watt ) ! greate/ exp]im5t] ( 8 age 9 a closely alli$ field4 ,que/ions ( sugge/ion aside1 x illu/rates ! te*nical quality ( ,watt's m9d1 mak+ x obvi\s t he 0 no m]e +5i\s me*anic1 :o /umbl$ ^u 8 inv5tion4 ,he 01 9 po9t ( fact1 a c>efully tra9$ sci5tific exp]im5t]1 fully equipp$ ) all ! special k ( 8 "t 9 its application to ! p>ticul> bran* ( pneumatics to :i* he gave att5tion4 ,! fir/ & mo/ obvi\s defect 9 ! ,newcom5 eng9e 01 z ,watt discov]$1 t ! alt]nat+ cool+ & heat+ ( ! cyl9d] result$ 9 an unavoidable wa/e ( en]gy4 ,! app>atus work$1 x w be recall$1 by ! introduction ( /eam into a v]tical cyl9d] b5ea? ! pi/on1 ! cyl9d] be+ op5 above ! pi/on to admit ! air4 ,! pi/on rod connect$ ) a beam susp5d$ 9 ! middle1 :i* op]at$ ! pump1 & :i* 0 weight$ at "o end 9 ord] to facilitate ! rais+ ( ! pi/on4 ,! /eam1 introduc$ "u l[ pressure1 sc>cely m ?an c\nt]act$ ! pressure ( ! air1 ! rais+ ( ! pi/on be+ l>gely accompli%$ by ! weight 9 "q4 ,( c\rse ! introduction ( ! /eam heat$ ! cyl9d]4 ,9 ord] to cond5se ! /eam & produce a vacuum1 wat] 0 inject$1 ! cyl9d] be+ !reby cool$4 ,a vacuum be+ ?us produc$ b5ea? ! cyl9d]1 ! pressure ( ! air f above ?ru/ ! cyl9d] d[n1 ?is be+ ! actual work+ ag5t4 ,x 0 = ?is reason t ! ,newcom5 eng9e 0 call$1 ) mu* propriety1 a pneumatic eng9e4 ,! action ( ! eng9e 0 v sl[1 & x 0 necess>y to employ a v l>ge pi/on 9 ord] to ga9 a consid]able p[]4 ,! fir/ idea t occurr$ to ,watt 9 connection ) ! probable improvem5t ( ?is me*anism did n look to ! alt]ation ( any ( ! g5]al features ( ! /ructure1 z reg>ds size or arrangem5t ( cyl9d]1 pi/on1 or beam1 or ! ess5tial pr9ciple ^u :i* ! eng9e work$4 ,8 entire att5tion 0 fix$ on ! discov]y ( a me?od by :i* ! loss ( heat ?r\gh p]iodical cool+ ( ! cyl9d] c\ld be avoid$4 ,we are told t he contemplat$ ! subject long1 & exp]im5t$ mu*1 be=e he rea*$ a satisfactory solution4 ,naturally en\gh 8 att5tion 0 fir/ direct$ t[>d ! cyl9d] itself4 ,he qu]i$ :e!r ! cyl9d] might n be made ( wood1 :i*1 ?r\gh its poor conduction ( heat1 might bett] equalize ! temp]ature4 ,exp]im5ts 9 ?is direction1 h[ev]1 produc$ no satisfactory result4 ,illu/ration3 ,,watt',s ,,e>lie/ ,,type ,,( ,,pump+ ,,eng9e4 ,! l[] figure %[s ! ru9s ( ,watt's fam\s eng9e ,old ,bess4 ,! upp] figure %[s a recon/ruct$ model ( ! ,old ,bess eng9e4 ,x w be not$ t ! walk+ beam is precisely ( ! ,newcom5 type4 ,9 fact1 ! entire eng9e is obvi\sly only a modification ( ! ,newcom5 eng9e4 ,x _h1 h[ev]1 c]ta9 highly important improvem5ts1 z describ$ 9 ! text4 ,!n at la/ an inspiration came to him4 ,:y n connect ! cyl9d] ) ano!r receptacle1 9 :i* ! cond5sation ( ! /eam c\ld be effect$8 ,! idea 0 a brilliant "o1 b nei!r its orig9ator nor any o!r man ( ! p]iod c\ld possibly h realiz$ its va/ & all-compreh5d+ importance4 ,= 9 t idea 0 conta9$ ! g]m ( all ! future ( /eam z a motive p[]4 ,inde$1 x sc>cely suffices to speak ( x z ! g]m m]ely2 ! ?+ itself 0 !re1 requir+ only ! elaboration ( details to br+ x to p]fection4 ,watt imm$iately set to "w to put 8 brilliant conception ( ! sep>ate cond5s] to ! te/ ( exp]im5t4 ,he connect$ ! cyl9d] ( a ,newcom5 eng9e ) a receptacle into :i* ! /eam c\ld be dis*>g$ aft] do+ its "w on ! pi/on4 ,! receptacle 0 kept con/antly cool$ by a jet ( wat]1 ?is wat] & ! wat] ( cond5sation1 toge!r ) any air or uncond5s$ /eam t might rema9 9 ! receptacle1 be+ con/antly remov$ ) ! aid ( an air pump4 ,! app>atus at once demon/rat$ its practical effici5cy1--& ! mod]n /eam eng9e _h come into exi/5ce4 ,x 0 9 ! ye> #agfe1 :5 ,watt 0 tw5ty-n9e ye>s old1 t he made 8 fir/ revolution>y exp]im5t1 b 8 fir/ pat5ts 7 n tak5 out until #agfi1 by :i* "t 8 eng9e _h atta9$ a relatively high degree ( p]fection4 ,9 fur!r+ 8 idea ( keep+ ! cyl9d] at an ev5 temp]ature1 he _h provid$ a cov]+ = x1 :i* might consi/ ( wood or o!r poorly conduct+ mat]ial1 or a s-call$ jacket ( /eam--t is to say1 a portion ( /eam admitt$ into ! clos$ *amb] surr\nd+ ! cyl9d]4 ,moreov]1 ! cyl9d] _h be5 clos$ at ! top1 & a portion ( /eam admitt$ above ! pi/on1 to take ! place ( ! atmosph]e 9 produc+ ! d[n /roke4 ,?is /eam above ! pi/on1 x %\ld be expla9$1 did n connect ) ! cond5s+ receptacle1 s ! eng9e 0 /ill s+le-act+2 t is to say x p]=m$ "w only dur+ "o /roke ( ! pi/on4 ,a description ( ! me*anism at ?is /age ( its developm5t may be/ be giv5 9 ! words ( ! inv5tor himself1 z conta9$ 9 8 specifications 9 ! application = pat5t on 8 improvem5ts 9 #agfi4 ,my me?od ( less5+ ! consumption ( /eam1 & consequ5tly fuel1 9 fire-eng9es1 consi/s ( ! foll[+ pr9ciples3 ,fir/1 ,t vessel 9 :i* ! p[]s ( /eam are to be employ$ to "w ! eng9e1 :i* is call$ ! cyl9d] 9 common fire-eng9es1 & :i* ,i call ! /eam vessel1 mu/1 dur+ ! :ole "t ! eng9e is at "w1 be kept z hot z ! /eam t ent]s x2 fir/ by enclos+ x 9 a case ( wood1 or any o!r mat]ials t transmit heat sl[ly2 secondly1 by surr\nd+ x ) /eam or o!r heat$ bodies2 &1 ?irdly1 by suff]+ nei!r wat] nor any o!r sub/ance cold] ?an ! /eam to ent] or t\* x dur+ t "t4 ,secondly1 ,9 eng9es t are to be work$ :olly or p>tially by cond5sation ( /eam1 ! /eam is to be cond5s$ 9 vessels di/9ct f ! /eam vessels or cyl9d]s1 al?\gh occasionally communicat+ ) !m2 ^! vessels ,i call cond5s]s2 &1 :il/ ! eng9es are work+1 ^! cond5s]s ought at lea/ to be kept z cold z ! air 9 ! neighborhood ( ! eng9es1 by application ( wat] or o!r cold bodies4 ,?irdly1 ,:atev] air or o!r ela/ic vapor is n cond5s$ by ! cold ( ! cond5s]1 & may imp$e ! work+ ( ! eng9e1 is to be drawn out ( ! /eam vessels or cond5s]s by means ( pumps1 wr\ght by ! eng9es !mselves1 or o!rwise4 ,f\r?ly1 ,i int5d 9 _m cases to employ ! expansive =ce ( /eam to press on ! pi/ons1 or :atev] may be us$ in/ead ( !m1 9 ! same mann] 9 :i* ! pressure ( ! atmosph]e is n[ employ$ 9 common fire-eng9es4 ,9 cases :]e cold wat] c n be _h 9 pl5ty1 ! eng9es may be wr\ght by ?is =ce ( /eam only1 by dis*>g+ ! /eam into ! air aft] x has done its (fice4 ,six?ly1 ,i int5d 9 "s cases to apply a degree ( cold n capable ( r$uc+ ! /eam to wat]1 b ( contract+ x consid]ably1 s t ! eng9es %all be work$ by ! alt]nate expansion & contraction ( ! /eam4 ,la/ly1 ,in/ead ( us+ wat] to r5d] ! pi/ons & o!r p>ts ( ! eng9e air-& /eam-tight1 ,i employ oils1 wax1 res9\s bodies1 fat ( animals1 quicksilv] & o!r metals 9 _! fluid /ate4 ,,rot>y ,,motion ,x mu/ be und]/ood t ,watt's eng9e 0 at fir/ us$ exclusively z an app>atus = pump+4 ,= "s "t !re 0 no practical attempt to apply ! me*anism to any o!r purpose4 ,t x might be s appli$1 h[ev]1 0 soon manife/1 9 consid]ation ( ! relative spe$ ) :i* ! pi/on n[ act$4 ,x 0 n until #agha1 h[ev]1 t ,watt's second pat5t 0 tak5 out1 9 :i* devices are describ$ calculat$ to conv]t ! reciprocat+ motion ( ! pi/on into motion ( rotation1 9 ord] t ! eng9e might drive ord9>y ma*9]y4 ,x seems to be conc$$ t ,watt 0 himself ! orig9ator ( ! idea ( mak+ ! application ?r\gh ! m$ium ( a crank & fly-:eel su* z are n[ univ]sally employ$4 ,b ! ye> be=e ,watt took out 8 second pat5t1 ano!r inv5tor nam$ ,james ,pic>d _h pat5t$ ?is device ( crank & connect+ rod1 hav+1 x is alleg$1 obta9$ ! idea f a workman 9 ,watt's employ4 ,:atev] be ! tru? z to ?is po9t1 ,pic>d's pat5t made x necess>y = ,watt to f9d "s alt]native device1 & aft] exp]im5t+1 he hit ^u ! s-call$ sun & planet ge>+1 & h5ce=? ?is 0 us$ on 8 rot>y eng9es until ! "t = ! expiration ( ,pic>d's pat5t1 aft] :i* ! simpl] & m satisfactory crank & fly-:eel 7 adopt$4 ,9 ! meantime1 ,watt _h associat$ himself ) a bus9ess p>tn] nam$ ,b\lton1 "u ! firm "n ( ,b\lton & ,watt4 ,9 #aggf a special act ( legislation ext5d+ ! t]m ( ,watt's orig9al pat5t = a p]iod ( tw5ty-five ye>s _h be5 secur$4 ,all infr+em5ts 7 vigor\sly prosecut$1 & ! inv5tor1 x is gratify+ to reflect1 %>$ fully 9 ! monet>y proce$s t accru$ f 8 inv5tion4 ,illu/ration3 ,,watt',s ,,rotative ,,eng9e4 ,! l[] figure %[s ! e>lie/ type ( me*anism ?r\gh :i* ,watt appli$ 8 eng9e to o!r uses ?an t ( pump+4 ,! s-call$ sun-&-planet ge>+1 ?r\gh :i* rot>y motion 0 atta9$1 is se5 at ! l[] "r-h& corn] ( ! figure4 ,! upp] figure %[s a lat] & mu* improv$ type ( ! ,watt eng9e1 9 :i* ! sun-&-planet ge>+ has be5 supplant$ by a simple crank4 ,not)/&+ ! e>ly recognition ( ! possibility ( secur+ rot>y motion ) ,watt's p]fect$ ,newcom5 eng9e1 x 0 long be=e ! full possibilities ( ! application ( ?is pr9ciple 7 realiz$1 ev5 by ! mo/ practical ( ma*9i/s4 ,watt himself app>5tly appreciat$ ! possibilities no m fully ?an ! o!rs1 z ! use ( 8 fam\s eng9es ,beelzebub & ,old ,bess 9 ! e/abli%m5t ( ,b\lton & ,watt amply te/ifies4 ,x appe>s t ,b\lton _h be5 an ext5sive manufactur] ( ornam5tal metal articles4 ,to drive 8 ma*9]y at ,soho he employ$ two l>ge wat] :eels1 tw5ty-f\r feet 9 diamet] & six feet wide4 ,^! suffic$ = 8 purpose "u ord9>y conditions1 b 9 dry wea!r f six to t5 horses 7 requir$ to aid 9 driv+ ! ma*9]y4 ,:5 ,watt's p]fect$ eng9e 0 available1 h[ev]1 ?is 0 utiliz$ to pump wat] f ! tail race back to ! head race1 t x might be us$ ov] & ov]4 ,old ,bess _h a cyl9d] ?irty-?ree in*es 9 diamet] ) sev5-foot /roke1 op]at+ a pump tw5ty-f\r in*es 9 diamet]2 x !re=e _h rem>kable effici5cy z a pump+ app>atus4 ,b ( c\rse x utiliz$1 at be/1 only a portion ( ! work+ en]gy conta9$ 9 ! /eam2 & ! wat] :eels 9 turn c\ld utilize n m ?an fifty p] c5t4 ( ! /ore ( en]gy :i* ! pump transf]r$ to ! wat] 9 rais+ x4 ,!re=e1 su* use ( ! /eam eng9e involv$ a mo/ wa/eful exp5diture ( en]gy4 ,x 0 long1 h[ev]1 be=e ! practical ma*9i/s c\ld be made to believe t ! secur+ ( direct rot>y p[] f ! pi/on c\ld be satisfactorily accompli%$4 ,x 0 only aft] ! introduction ( high] spe$ & heavi] fly-:eels1 toge!r ) improv$ gov]nors1 t ! spe$ ( rotation 0 s equaliz$ z to meet satisfactorily ! requirem5ts ( ! practical eng9e]1 & ultimately to displace ! wa/eful me?od ( secur+ rot>y motion indirectly ?r\gh ! aid ( pump & wat] :eel4 ,x may be add$1 t ! c5trifugal gov]nor1 ) :i* mod]n eng9es are provid$ to regulate _! spe$1 0 ! inv5tion ( ,watt himself4 ,,f9al ,,improvem5ts ,,& ,,miss$ ,,opportunities ,9 ! ye> #aghb ,watt took out pat5ts :i* conta9$ specifications = ! two additional improvem5ts t con/itut$ 8 f9al contribution to ! production ( ! /eam eng9e4 ,! fir/ ( ^! provid$ = ! connection ( ! cyl9d] *amb] on ea* side ( ! pi/on ) ! cond5s]1 s t ! eng9e became d\ble act+4 ,! second introduc$ ! v important pr9ciple1--f ! /&po9t ( economy 9 ! use ( /eam--( %utt+ (f ! supply ( /eam f ! cyl9d] :ile ! pi/on has only p>tially trav]s$ its ?ru/1 & all[+ ! rema9d] ( ! ?ru/ to be accompli%$ ?r\gh ! expansion ( ! /eam4 ,! application ( ! fir/ ( ^! pr9ciples obvi\sly adds greatly to ! effici5cy ( ! eng9e1 & 9 practise x 0 f\nd t ! application ( ! second pr9ciple produces a v great sav+ 9 /eam1 & ?us adds mat]ially to ! economical work+ ( ! eng9e4 ,all ( ,watt's eng9es cont9u$ to make use ( ! walk+ beam atta*$ to ! pi/on = ! transmission ( p[]2 & eng9e]s 7 v sl[ inde$ to recognize ! fact t 9 _m--9 fact 9 mo/--cases ?is contrivance may advantage\sly be done away )4 ,! recognition ( ?is fact con/itutes "o ( ! ?ree really important advances t h be5 made 9 ! /eam eng9e s9ce ! "t ( ,watt4 ,! o!r two advances consi/ ( ! utilization ( /eam "u high pressure1 & ( ! introduction ( ! pr9ciple ( ! comp\nd eng9e4 ,nei!r ( ^! ideas 0 unkn[n to ,watt1 s9ce ! utilization ( /eam "u high pressure 0 advocat$ by 8 contempor>y1 ,trevi?ick1 :ile ! comp\nd eng9e 0 inv5t$ by ano!r contempor>y nam$ ,hornbl[]4 ,p]haps ! v fact t ^! rival inv5tors put =w>d ! ideas 9 "q may h influ5c$ ,watt to antagonize !m2 9 p>ticul> s9ce 8 firm came into legal conflict ) ea* ( ! o!r inv5tors4 ,at any rate1 ,watt cont9u$ to ! end ( 8 life to be an ard5t advocate ( l[ pressure = ! /eam eng9e1 & 8 firm ev5 attempt$ to h laws pass$ mak+ x illegal--on ! gr\nd ( dang] to human life--to utilize high-pressure /eam1 su* z employ$ by ,trevi?ick4 ,possibly ! cons]vatism ( increas+ age may also h _h its %>e 9 r5d]+ ,watt antagoni/ic to ! new ideas2 = he 0 simil>ly antagoni/ic to ! idea ( apply+ /eam to ! purposes ( locomotion4 ,trevi?ick1 among o!rs1 _h1 z we %all see 9 due c\rse1 made su* application ) a/oni%+ success1 produc+ a /eam automobile :i* trav]s$ ! highway successfully4 ,9 8 e>li] ye>s ,watt _h conceiv$ ! same idea1 & _h op5ly express$ 8 op9ion t ! /eam eng9e might be us$ = ?is purpose4 ,b late 9 life he 0 s antipa!tic to ! idea t he is said to h put a clause 9 ! lease ( 8 h\se1 provid+ t no /eam c>riage %\ld "u any pretext be all[$ to approa* x4 ,^! incid5ts h importance z %[+--z we %all see illu/rat$ aga9 & aga9 9 o!r fields--! disa/r\s influ5ce 9 ret>d+ progress t may be ex]cis$ by ev5 ! greate/ ( sci5tific discov]]s1 :5 au?ority well e>n$ 9 e>li] ye>s is ex]cis$ 9 an un=tunate direction lat] 9 life4 ,b su* incid5ts z ^! are inconsequ5tial 9 det]m9+ ! position among ! _w's work]s ( ! man :o 0 almo/ solely responsible = ! trans=mation ( ! /eam eng9e f an exp5sive & relatively ineffective pump+ app>atus1 to ! great c5tral p[] t has ev] s9ce mov$ ! major "p ( ! _w's ma*9]y4 ,,! ,,supreme ,,importance ,,( ,,watt ,x is speak+ well )9 b\nds to say t no o!r inv5tion )9 hi/orical times has _h s important an influ5ce ^u ! production ( prop]ty--:i*1 z we h se51 is ! gauge ( ! _w's "w--z ?is inv5tion ( ! /eam eng9e4 ,we h foll[$ ! hi/ory ( t inv5tion 9 "s detail1 because ( its supreme importance4 ,to ! read] :o 0 n previ\sly famili> ) t hi/ory1 x may seem surpris+ t aft] a lapse ( a little ov] a c5tury "o "n & "o alone %\ld be popul>ly rememb]$ 9 connection ) ! inv5tion2 :]eas 9 po9t ( fact v>i\s work]s _h a %>e 9 ! a*ievem5t1 & ! man ^: "n is rememb]$ 0 among ! la/ to ent] ! field4 ,we h se5 t ! /eam eng9e exi/$ z a practical work+ ma*9e sev]al decades be=e ,watt made 8 fir/ inv5tion2 & t :at ,watt really accompli%$ 0 m]ely ! p]fect+ ( an app>atus :i* already _h atta9$ a consid]able measure ( effici5cy4 ,!re w\ld seem1 !n1 to be a c]ta9 lack ( ju/ice 9 ascrib+ supreme importance to ,watt 9 connection ) ! /eam eng9e4 ,yet ?is measure ( inju/ice we %all f9d1 z we exam9e ! hi/ory ( v>i\s inv5tions1 to be met$ always by po/]ity 9 det]m9+ ! /atus ( ! m5 :om x is pleas$ to honor4 ,"o practical rule1 & "o only1 has always det]m9$ to :om ! *ief %>e ( glory %all be ascrib$ 9 connection ) any useful inv5tion4 ,! "q is nev] ask$ z to :o 0 ! orig9ator ( ! idea1 or :o made ! fir/ t5tative ef=ts t[>ds its utilization1--or1 if ask$ by ! hi/orical se>*]1 x is ignor$ by ! g5]ality ( mank9d4 ,s f> z ! public v]dict1 :i* 9 ! la/ resort det]m9es fame1 is conc]n$1 ! "o "q is1 ,:o p]fect$ ! app>atus s t x came to h g5]al practical utility8 ,x may be1 & inde$ x usually is ! case1 t ! man :o fir/ accompli%$ ! f9al elaboration ( ! idea1 made b a comp>atively slight advance ^u 8 pr$ecessors2 ! e>ly work]s produc$ a ma*9e t 0 almo/ a success2 only "s little flaw rema9$ 9 _! plans4 ,!n came ! p]fect]1 :o hit ^u a device t w\ld correct ?is la/ defect1--& at la/ ! me*anism1 :i* hi!rto _h be5 only a curiosity1 became a practical work+ ma*9e4 ,9 ! case ( ! /eam eng9e1 x might be said t ev5 a small] feat ?an ?is rema9$ to be accompli%$ :5 ,watt came ^u ! sc5e2 s9ce ! ,newcom5 eng9e 0 actually a practical work+ app>atus4 ,b ! all-ess5tial ?+ to rememb] is t ?is ,newcom5 eng9e 0 us$ = a s+le purpose4 ,x suppli$ p[] = pump+ wat]1 & = no?+ else4 ,nei!r did x h possibilities mu* beyond ?is1 until ! all-ess5tial modification 0 sugge/$ by ,watt1 ( exhau/+ its /eam into ext]ior space4 ,?is modification is 9 "o s5se a m]e detail1 yet x illu/rates once m ! =ce ( ,mi*elangelo's fam\s decl>ation t trifles make p]fect2 = :5 once x 0 te/$1 ! :ole practical "* ( ! /eam eng9e 0 *ang$4 ,f a wa/eful consum] ( fuel1 capable ( runn+ a pump at great exp5se1 x became at once a relatively economical us] ( en]gy1 capable ( p]=m+ almo/ any mann] ( "w4 ,ne$less to say1 its possibilities 9 ?is direction 7 n imm$iately realiz$1 9 !ory or 9 practise2 yet ! conque/ t x made ( almo/ ! entire field ( labor result$ 9 ! mo/ rapid trans=mation ( indu/rial conditions t ! _w has ev] exp]i5c$4 ,aft] all1 !n1 !re is b little inju/ice 9 t public v]dict :i* rememb]s ,james ,watt z ! inv5tor1 r ?an z ! m]e p]fect]1 ( ! /eam eng9e4 ,,! ,,p]sonality ,,( ,,james ,,watt ,! man :o occupies ?is all-important position 9 ! indu/rial _w dem&s a few m words z to 8 p]sonality4 ,8 "w we h suffici5tly consid]$1 b be=e we pass on to ! "w ( 8 successors1 x w be wor? our :ile to le>n some?+ m ( ! e/imate plac$ ^u ! man himself4 ,let u quote1 !n1 f "s records writt5 by m5 :o 7 ( ! same g5]ation4 ,indep5d5tly ( 8 great atta9m5ts 9 me*anics1 ,mr4 ,watt 0 an extraord9>y & 9 _m respects a wond]ful man4 ,p]haps no individual 9 8 age possess$ s mu*1 or rememb]$ :at he _h read s accurately & well4 ,he _h inf9ite quickness ( appreh5sion1 a prodigi\s memory1 & a c]ta9 rectify+ & me?odiz+ p[] ( und]/&+ :i* extract$ some?+ preci\s out ( all t 0 pres5t$ to x4 ,8 /ores ( miscellane\s k 7 imm5se1 & yet less a/oni%+ ?an ! comm& he _h at all times ov] !m4 ,x seem$ z if e subject t 0 casually />t$ 9 conv]sation _h be5 t :i* he _h be5 la/ occupi$ 9 /udy+ & exhau/+2 su* 0 ! copi\sness1 ! precision1 & ! admirable cle>ness ( ! in=mation :i* he p\r$ out ^u x )\t ef=t or hesitation4 ,nor 0 ?is promptitude & compass ( k conf9$1 9 any degree1 to ! /udies connect$ ) 8 ord9>y pursuits4 ,t he %\ld h be5 m9utely & ext5sively skill$ 9 *emi/ry1 & ! arts1 & 9 mo/ ( ! bran*es ( physical sci5ce1 might1 p]haps1 h be5 conjectur$2 b x c\ld n h be5 inf]r$ f 8 usual occupations1 & probably is n g5]ally kn[n1 t he 0 curi\sly le>n$ 9 _m bran*es ( antiquity1 metaphysics1 m$ic9e1 & etymology1 & p]fectly at home 9 all ! details ( ar*itecture1 music1 & law4 ,he 0 well acqua9t$1 too1 ) mo/ ( ! mod]n languages1 & famili> ) _! mo/ rec5t lit]ature4 ,nor 0 x at all extraord9>y to he> ! great me*anician & eng9e] detail+ & exp\nd+1 = h\rs toge!r1 ! metaphysical !ories ( ! ,g]man logicians1 or criticiz+ ! measures or ! matt] ( ! ,g]man poetry4 ,x is ne$less to say1 t ) ^? va/ res\rces1 8 conv]sation 0 at all times ri* & in/ructive 9 no ord9>y degree4 ,b x 01 if possible1 /ill m pleas+ ?an wise1 & _h all ! *>ms ( famili>ity1 ) all ! sub/antial treasures ( k4 ,no man c\ld be m social 9 8 _s1 less assum+ or fa/idi\s 9 8 mann]s1 or m k9d & indulg5t t[>ds all :o approa*$ him4 ,8 talk1 too1 ?\gh ov]fl[+ ) in=mation1 _h no resemblance to lectur+1 or solemn disc\rs+2 b1 on ! contr>y1 0 full ( colloquial _s & pleasantry4 ,he _h a c]ta9 quiet & grave humor1 :i* ran ?r\gh mo/ ( 8 conv]sation1 & a ve9 ( temp]ate jocul>ity1 :i* gave inf9ite ze/ & effect to ! cond5s$ & inexhau/ible in=mation :i* =m$ its ma9 /aple & *>act]i/ic4 ,!re 0 a little air ( affect$ te/9ess1 & a tone ( pret5d$ rebuke & contradiction1 :i* he us$ t[>ds 8 y\ng] fri5ds1 t 0 always felt by !m z an ende>+ m>k ( 8 k9dness & famili>ity1 & priz$ accord+ly1 f> beyond all ! solemn complim5ts t proce$$ f ! lips ( au?ority4 ,8 voice 0 deep & p[]ful2 ?\gh he commonly spoke 9 a l[ & some:at monoton\s tone1 :i* h>moniz$ admirably ) ! weight & brevity ( 8 obs]vations1 & set (f to ! greate/ advantage ! pleasant anecdotes :i* he deliv]$ ) ! same grave tone1 & ! same calm smile play+ sob]ly on 8 lips4 ,illu/ration3 ,,james ,,watt4 ,!re 0 no?+ ( ef=t1 inde$1 or ( impati5ce1 any m ?an ( pride or levity1 9 8 demeanor2 & !re 0 a f9] expression ( repos+ /r5g?1 & mild self-possession 9 8 mann]1 ?an we ev] recollect to h met ) 9 any o!r p]son4 ,he _h 9 8 "* ! utmo/ abhorr5ce = all sorts ( =w>dness1 p>ade1 & pret5sion2 & inde$ nev] fail$ to put all su* impo/ors out ( c\nt5ance1 by ! manly pla9ness & hone/ intrepidity ( 8 language & deportm5t4 ,he 0 twice m>ri$1 b has left no issue b "o son1 associat$ ) him 9 8 bus9ess & /udies1 & two gr&*ildr5 by a daught] :o pr$eceas$ him4 ,he 0 fell[ ( ! ,royal ,societies bo? ( ,london & ,ed9burgh1 & "o ( ! few ,engli%m5 :o 7 elect$ memb]s ( ! ,national ,in/itute ( ,france4 ,all m5 ( le>n+ & ( sci5ce 7 8 cordial fri5ds2 & su* 0 ! influ5ce ( 8 mild "*1 & p]fect fairness & lib]ality1 ev5 ^u ! pret5d] to ^! accompli%m5ts1 t he liv$ to dis>m ev5 envy itself1 & di$1 we v]ily believe1 )\t a s+le enemy4 ,,vi ,,! ,,ma/] ,,work] ,we h already po9t$ out at "s l5g? t1 9 ! h&s ( ,watt1 ! /eam eng9e came at once to be a relatively p]fect app>atus1 & t only ?ree really important modifications h be5 appli$ to x s9ce ! day ( its great p]fect]4 ,^! modifications1 z already nam$1 are ! do+ away ) ! walk+ beam1 ! utilization ( high pressure /eam1 & ! developm5t ( ! comp\nd eng9e4 ,ea* ( ^! developm5ts requires a few words ( explanation4 ,! ret5tion ( ! heavy walk+ beam = s long a "t aft] ! /eam eng9e ( ,watt _h be5 appli$ to ! v>i\s purposes ( ma*9]y1 illu/rates ! p[] ( a pre-conceiv$ idea4 ,) ! ,newcom5 eng9e ?is beam 0 an ess5tial1 s9ce x 0 necess>y to h a weight to assi/ 9 rais+ ! pi/on4 ,b ) ! introduction ( /eam r ?an air z ! actual p[] to pu% ! pi/on1 & 9 p>ticul> ) ! elaboration ( ! d\ble-*amb] cyl9d]1 ) /eam act+ equally on ei!r side ( ! pi/on1 ! necessity = reta9+ ?is cumb]some contrivance no long] exi/$4 ,yet we f9d all ! eng9es made by ,watt himself1 & ne>ly all ^? ( 8 contempor>ies1 cont9u+ to utilize ?is means ( transmitt+ ! p[] ( ! pi/on4 ,ev5 ! road locomotive1 z illu/rat$ by t fir/ wond]ful "o ( ,trevi?ick's & su* colli]y locomotives z ,puff+ ,billy & ,locomotion1 utiliz$ ! same plan4 ,x 0 n until almo/ a g5]ation lat] t x became cle> to ! me*anics t 9 _m cases1 inde$ 9 mo/ cases1 ?is awkw>d means ( transmitt+ p[] 0 really a ne$lessly wa/eful "o1 & t ) ! aid ( fly-:eel & crank-%aft ! ?ru/ ( ! pi/on might be directly appli$ to ! :eel x 0 de/9$ to turn1 q z well z ?r\gh ! int]m$i>y *annel ( ! additional lev]4 ,! utility ( ! beam has1 inde$1 /ill comm5d$ x = c]ta9 purposes1 notably = ! propulsion ( side-:eel /eam]s1 su* z ! famili> ,am]ican f]ryboat4 ,b aside f su* exceptional uses1 ! beam has practically pass$ out ( exi/5ce4 ,!re 0 no new pr9ciple involv$ 9 effect+ ?is *ange4 ,x 0 m]ely ano!r illu/ration ( ! famili> fact t x is difficult to d ?+s simply4 ,z a rule1 inv5tors fumble = a long "t ) r\ndab\t & complex ways ( do+ ?+s1 be=e a direct & simple me?od occurs to !m4 ,9 o!r words1 ! highe/ developm5t (t5 passes f ! complex to ! simple1 illu/rat+1 z x 71 an oscillation 9 ! great law ( evolution4 ,s 9 ?is case1 ev5 s great an inv5tor z ,watt fail$ to see ! utility ( do+ away ) ! cumb]some /ructure :i* 8 own inv5tion _h made no long] a necessity1 b r a h9drance to ! application ( ! /eam eng9e4 ,h[ev]1 a new g5]ation1 no long] "u ! ?raldom ( ! ideas ( ! great inv5tor1 0 enabl$ to make ! *ange1 gradually1 b 9 ! end effectively4 ,,high-,,pressure ,,/eam ,z reg>ds ! use ( /eam "u high pressure1 some:at ! same rem>ks apply1 s f> z conc]ns ! cons]vatism ( mank9d1 & ! influ5ce :i* a great m9d ex]ts ^u its g5]ation4 ,j :y ,watt %\ld h conceiv$ an antagonism to ! idea ( high-pressure /eam is n altoge!r cle>4 ,x has be5 sugge/$1 inde$1 t ?is might h be5 due to ! fact t a pr$ecessor ( ,watt _h inv5t$ a high-pressure eng9e :i* did n use ! pr9ciple ( cond5sation1 b exhau/$ ! /eam into op5 space4 ,z e>ly z #agbe1 inde$1 ,leupold 9 8 ,!atrum ,ma*9>um1 _h describ$ su* a non-cond5s+ eng9e1 :i*1 _h x be5 made practically useful1 w\ld h requir$ a high pressure ( /eam4 ,p>tly ?r\gh ! influ5ce ( ?is "w1 p]haps1 !re came to be an association betwe5 ! words high pressure & non-cond5s+1 s t ^! t]ms are consid]$ to be virtually synonym\s2 & s9ce ,watt's great contribution consi/$ ( an application ( ! idea ( cond5sation1 he 0 p]haps r5d]$ antagoni/ic to ! idea ( high pressure1 ?r\gh ?is psy*ological sugge/ion4 ,9 any ev5t1 ! antagonism unque/ionably exi/$ 9 8 m9d2 ?\gh x has (t5 en\gh be5 po9t$ out t ?is seems ! m curi\s s9ce high-pressure /eam w\ld s mu* bett] h facilitat$ ! application ( t o!r fam\s idea ( ,watt1 ! use ( ! expansive prop]ty ( /eam4 ,curi\sly en\gh1 h[ev]1 ! influ5ce ( ,watt l$ to exp]im5ts 9 high-pressure /eam ?r\gh an indirect *annel4 ,! contempor>y inv5tor1 ,trevi?ick1 9 connection ) 8 p>tn]1 ,bull1 _h made direct-act+ pump+ eng9es ) an inv]t$ cyl9d]1 fix$ 9 l9e ) ! pump rod1 & actually disp5s+ ) ! beam4 ,b z ^! eng9es us$ a jet ( cold wat] 9 ! exhau/ pipe to cond5se ! /eam1 ,b\lton & ,watt br\ght suit successfully = infr+em5t ( _! pat5t1 & ?us prev5t$ ,trevi?ick f exp]im5t+ fur!r 9 t direction4 ,he 0 oblig$1 !re=e1 to turn 8 att5tion to a diff]5t me?od1 & probably1 9 "p at lea/1 9 ?is way 0 l$ to introduce ! non-cond5s+1 relatively high-pressure eng9e4 ,?is 0 us$ ab\t ! ye> #ahjj4 ,at ! same "t some:at simil> exp]im5ts 7 made by ,oliv] ,evans 9 ,am]ica4 ,bo? ,trevi?ick & ,evans appli$ _! eng9es to ! propulsion ( road vehicles2 & ,trevi?ick is cr$it$ ) be+ ! fir/ man :o ran a /eam locomotive on a track1--a feat :i* he accompli%$ z e>ly z ! ye> #ahjd4 ,we are n "h conc]n$ ) ! details ( ?is accompli%m5t1 :i* w dem& our att5tion 9 a lat] *apt]1 :5 we come to discuss ! entire subject ( locomotive transportation4 ,b x is int]e/+ to recall t ! possibilities ( ! /eam eng9e 7 ?us e>ly realiz$1 ev5 ?\gh ano!r g5]ation elaps$ be=e !y 7 f9ally demon/rat$ to ! satisfaction ( ! public4 ,x is p>ticul>ly int]e/+ to note t 9 8 fir/ locomotive eng9e1 ,trevi?ick all[$ ! /eam exhau/ to escape into ! funnel ( ! eng9e to increase ! draught1--an exp$i5t :i* 0 s l>gely responsible = ,/eph5son's success ) 8 locomotive tw5ty ye>s lat]1 & :i* reta9s its utility 9 ! case ( ! mo/ highly develop$ mod]n locomotive4 ,trevi?ick 01 h[ev]1 entirely subord9at$ by ! great influ5ce ( ,watt1 & ! use ( high pressure 0 9 consequ5ce disc\nt5anc$ by ! lead+ me*anical eng9e]s ( ,engl& = "s decades4 ,meantime1 9 ,am]ica1 ! initiative ( ,evans l$ to a mu* e>li] g5]al use ( high-pressure /eam4 ,9 due c\rse1 h[ev]1 ! advantages ( /eam "u high pressure became evid5t to eng9e]s ev]y:]e1 & its conque/ 0 f9ally complete4 ,! ess5tial feature ( sup]-heat$ /eam is t x conta9s1 z ! "n implies1 an excess ( heat beyond ! quantity necess>y to produce m]e vaporization1 & t ! am\nt ( wat] repres5t$ 9 ?is vapor is n ! maximum possible "u giv5 conditions4 ,9 o!r words1 ! vapor is n saturat$4 ,x has be5 already expla9$ t ! am\nt ( vapor t c be tak5 up 9 a giv5 space "u a giv5 pressure v>ies ) ! temp]ature ( ! space4 ,"u normal conditions1 :5 a clos$ space exi/s above a liquid1 evaporation occurs f ! surface ( ! liquid until ! space is saturat$1 & no fur!r evaporation c occur s long z ! temp]ature & pressure are un*ang$4 ,if n[ ! same space is heat$ to a high] degree1 m vapor w be tak5 up until aga9 ! po9t ( saturation is atta9$4 ,b1 obvi\sly1 if ! space 7 disconnect$ ) ! liquid1 & !n heat$1 x w\ld acquire a capacity to take up m vapor1 & s long z ?is capacity 0 lat5t1 ! vapor pres5t w\ld exi/ 9 a sup]-heat$ condition4 ,illu/ration3 ,,old ,,ideas ,,& ,,new ,,appli$ ,,to ,,boil] ,,con/ruction4 ,! l[] figure %[s ,rob]t ,trevi?ick's fam\s boil]1 us$ 9 op]at+ 8 locomotive ab\t ! ye> #ahjd4 ,! orig9al is pres]v$ 9 ! ,s\? ,k5s+ton ,museum1 ,london4 ,! upp] figure %[s a mod]n tubul> boil]1 by way ( contra/4 ,x w be und]/ood f :at has be5 said be=e1 t ) all accessions ( heat1 ! expansive p[] ( ! vapor is increas$1--its molecules becom+ increas+ly active2 h5ce "o ( ! v obvi\s advantages ( sup]-heat$ /eam = ! purpose ( pu%+ a pi/on4 ,!re are o!r advantages1 h[ev]1 :i* are n at fir/ sight s app>5t1 hav+ to d ) ! prop]ties ( cond5sation4 ,to und]/& ^!1 we mu/ pay he$ = a few mom5ts to ! *anges t take place 9 /eam itself 9 ! c\rse ( its passage ?r\gh ! cyl9d]1 :]e x p]=ms its "w ^u ! pi/on4 ,_m ( ^! *anges 7 n fully und]/ood by ! e>li] exp]im5t]s1 includ+ ,watt4 ,inde$ ! !ory ( ! /eam eng9e1 or r ! g5]al !ory ( ! heat eng9e1 0 n work$ out until ! ye> #ahbd1 :5 ! ,fr5*man ,c>not took ! subject 9 h&1 & p]=m$ a s]ies ( classical exp]im5ts1 :i* l$ to a ne>ly complete !oretical exposition ( ! subject4 ,x rema9$1 h[ev]1 = ! /ud5ts ( !rmo-dynamics1 ab\t ! middle ( ! n9ete5? c5tury1 ) ,clausius & ,rank9e at _! head1 to p]fect ! !ory ( ! /eam eng9e1 & ! g5]al subject ( ! mutual relations ( heat & me*anical "w4 ,we are n "h conc]n$ ) any elaboration ( details1 b m]ely ) a few ( ! ess5tial pr9ciples :i* ent] practically into ! op]ation ( ! /eam eng9e4 ,x appe>s1 !n1 t :5 /eam ent]s ! cyl9d] & beg9s to ?ru/ back ! pi/on ( ! /eam eng9e1 a portion ( ! /eam is imm$iately cond5s$ on ! walls ( ! cyl9d]1 ow+ to ! fact t previ\s cond5sation ( /eam has cool$ ^! walls to a c]ta9 ext5t4 ,we h already po9t$ out t ,watt endeavor$ 9 8 e>li] exp]im5ts to ov]come ?is difficulty1 by equaliz+ ! temp]ature ( ! cyl9d] walls to ! greate/ practicable ext5t4 ,not)/&+ 8 ef=ts1 h[ev]1 & ^? ( numb]less lat] exp]im5t]s1 x /ill rema9s true t "u ord9>y conditions1 p>ticul>ly if /eam ent]s ! cyl9d] at ! saturation po9t1 a v consid]able cond5sation occurs4 ,inde$ ?is may am\nt to f ?irty to fifty p] c5t4 ( ! entire bulk ( wat] conta9$ 9 ! quantity ( /eam t ent]s ! cyl9d]4 ,?is cond5sation obvi\sly militates aga9/ ! expansive or work+ p[] ( ! /eam4 ,b n[ z ! /eam exp&s1 pu%+ =w>d ! cyl9d]1 x becomes correspond+ly r>efi$1 & imm$iately a portion ( ! cond5s$ /eam becomes aga9 vaporiz$1 & 9 s do+ x takes up a c]ta9 am\nt ( heat & r5d]s x lat5t4 ,?is disadvantage\s cycle ( molecul> trans=mations is v mu* modifi$ 9 ! case ( sup]-heat$ /eam1 = ! obvi\s reason t su* /eam may be v mu* bel[ ! saturation po9t1 & h5ce requires a v mu* great] l[]+ ( temp]ature 9 ord] to produce cond5sation ( any portion ( its mass4 ,)\t elaborat+ details1 x suffices to note t 9 all highly effici5t mod]n eng9es1 /eam is employ$ at a relatively high pressure1 & t sometimes ?is pressure becomes enorm\s4 ,,comp\nd ,,eng9es ,z to ! comp\nd eng9e1 t also1 z has be5 po9t$ out1 0 inv5t$ by a contempor>y ( ,watt1 ,jona?an ,hornbl[] by "n1 ^: pat5t be>s date ( #agha4 ,9 ,hornbl[]'s eng9e1 /eam 0 fir/ admitt$ to a small cyl9d]1 & !n1 aft] p]=m+ its "w on ! pi/on1 0 all[$ to escape1 n into a cond5s+ receptacle1 b into a l>g] cyl9d] :]e x p]=m$ fur!r "w ^u ano!r pi/on4 ,?is 0 obvi\sly an in/ance ( ! use ( /eam expansively1 & x has be5 po9t$ out t1 9 consequ5ce1 ,hornbl[] 0 ! fir/ to make use ( ?is idea 9 practise1 al?\gh x is said t ,watt's exp]im5ts _h ev5 at t "t cov]$ ?is field4 ,! application ( ! idea to ! movem5t ( ! second cyl9d]1 h[ev]1 appe>s to h be5 orig9al ) ,hornbl[]4 ,c]ta9ly x ow$ no?+ to ,watt1 :o refus$ to accept ! idea1 & cont9u$ ?r\gh\t 8 life to fr[n ^u ! comp\nd eng9e4 ,nev]!less1 ! device _h great utility1 z subsequ5t exp]im5ts 7 v fully to demon/rate4 ,! comp\nd eng9e 0 reviv$ by ,woolf 9 #ahjd1 & 8 "n r ?an ,hornbl[]'s is commonly associat$ ) x4 ,! latt] exp]im5t] demon/rat$ t ! comp\nd eng9e has two important m]its z aga9/ ! simple eng9e4 ,"o ( ^! is t ! sum ( ! two =ces ex]t$ by ! jo9t action results 9 a m ev5 & cont9u\s pressure ?r\gh\t ! cycle ?an c\ld be accompli%$ by ! action ( a s+le cyl9d]4 ,to und]/& ?is x mu/ be recall$ t :5 us+ ! expansive prop]ty ( /eam1 ! pi/on ?ru/ c\ld n possibly be uni=m1 s9ce ! greate/ pressure ex]t$ by ! /eam w\ld be ex]t$ at ! mom5t be=e x 0 %ut (f f ! boil]1 & its pressure mu/ !n decrease progressively1 z x ex]ts m & m "w ^u ! pi/on & becomes m exp&$1 ?us obvi\sly reta9+ less ela/ic en]gy4 ,! op]ation ( ! fly-:eel l>gely comp5sates ?is diff]5ce ( pressure 9 practise1 b x w\ld be obvi\sly advantage\s c\ld ! pressure be equaliz$2 &1 z j /at$1 ! comp\nd eng9e t5ds to produce ?is result4 ,! second1 & p]haps ! m important m]it ( ! comp\nd eng9e is1 t x is f\nd 9 practise to keep ! cyl9d]s at a m uni=m temp]ature4 ,a mom5t's reflection makes x cle> :y ?is %\ld be ! case1 s9ce 9 a s+le-cyl9d] eng9e ! exhau/ connects ) ! cool cond5s]1 :]eas 9 ! comp\nd eng9e ! exhau/ f ! fir/ cyl9d] connects ) ! second cyl9d] at only slightly l[] temp]ature4 ,9 _m mod]n eng9es a ?ird cyl9d] & sometimes ev5 a f\r? is add$1 con/itut+ :at are call$ respectively triple-expansion & quadruple-expansion eng9es4 ,! triple-expansion sy/em is v g5]ally employ$1 especially :]e x is peculi>ly desirable to economize fuel1 z1 = example1 9 ! case ( %ips4 ,illu/ration3 ,,comp\nd ,,eng9es4 ,! l[] figure illu/rates ! use ( a mod]n comp\nd eng9e1 directly op]at+ ! propell] %aft ( a /eam%ip4 ,! middle figure %[s a simil>ly direct application ( p[] to ! axes ( paddle :eels4 ,! upp] figure %[s ! application ( p[] ?r\gh a walk+ beam simil> 9 pr9ciple to t ( ! orig9al ,newcom5 & ,watt eng9es4 ,,rot>y ,,eng9es ,all ^! improvem5ts1 x w be obs]v$1 h to d ) details t d n greatly modify ! /eam eng9e f ! orig9al type4 ,! cyl9d] ) its closely fitt+ pi/on1 z introduc$ 9 ! ,newcom5 eng9e1 is reta9$ & con/itutes ! ess5tial me*anism ?r\gh :i* ! en]gy ( /eam is transf]r$ into me*anical en]gy4 ,b f a comp>atively remote p]iod ! idea has prevail$ t x might be possible to utilize a diff]5t pr9ciple2 t1 9 %ort1 if ! /eam in/ead ( be+ made to press aga9/ a pi/on 7 all[$ to ru% aga9/ fan-l blades1 adju/$ to an axle1 x might cause blades & axle to revolve1 precisely z a w9dmill is made to revolve by ! pressure ( ! w9d1 or ! turb9e :eel by ! pressure ( wat]4 ,9 a ^w1 x has be5 believ$ t a turb9e eng9e might be con/ruct$1 :i* w\ld utilize ! en]gy ( ! /eam z advantage\sly z x is utiliz$ 9 ! pi/on eng9e1 & at ! same "t w\ld communicate its p[] z a direct rotation1 in/ead ( z a /raight ?ru/ t mu/ be translat$ into a rot>y motion by means ( a crank or o!r me*anism4 ,9 po9t ( fact1 ,james ,watt himself inv5t$ su* an eng9e1 & pat5t$ x 9 #aghb1 ?\gh !re is no evid5ce t he ev] con/ruct$ ev5 a work+ model4 ,8 pat5t specifications %[ a pi/on 9 ! =m ( a closely-fitt+ radial arm1 project+ f an axial %aft 9 a cyl9d]4 ,an abutm5t1 arrang$ z a flap is h+$ ne> a recess 9 ! side ( ! cyl9d]1 & sw+s :ile rema9+ 9 contact ) ! pi/on4 ,/eam is admitt$ to ! *amb] on "o side ( ! flap1 & s causes an unbalanc$ pressure ^u ! radial arm4 ,?is arrangem5t has be5 re-inv5t$ sev]al times4 ,ess5tially ! same pr9ciple is utiliz$ by ,jo%ua ,r\tl$ge1 ^: "n is well kn[n 9 connection ) ! eng9e]'s slide-rule4 ,a model ( ?is eng9e is pres]v$ 9 ! ,s\? ,k5s+ton ,museum1 & ! app>atus is describ$ 9 ! catalogue ( ! ,museum z foll[s3 ,! pi/on revolves on a %aft pass+ ?r\gh ! c5tre ( ! cyl9d] cas+4 ,! flap or valve h+$ to ! cas+1 ) its free end re/+ ^u ! pi/on1 acts l ! bottom ( an ord9>y eng9e cyl9d]4 ,! /eam inlet port is on "o side ( ! h+e1 & ! exhau/ port on ! o!r4 ,! admission ( /eam is controll$ by a side valve1 actuat$ by an ecc5tric on ! fly-:eel %aft1 s t ! eng9e c\ld "w expansively1 & ! /eam pressure resi/+ ! lift+ ( ! flap w\ld also be greatly r$uc$1 s dim9i%+ ! knock at ?is po9t1 :i*1 h[ev]1 w\ld always be a s]i\s cause ( tr\ble4 ,! exhau/ /eam passes d[n to a jet cond5s]1 provid$ ) a supply ( wat] f a conta9+ tank1 f :i* ! injection is admitt$ ?r\gh a regulat+ valve4 ,! air pump1 :i* draws ! air & wat] f ! cond5s] & dis*>ges !m ?r\gh a pipe pass+ out at ! end ( ! tank1 is a rot>y ma*9e con/ruct$ l ! eng9e & driv5 by spur ge>+ f ! fly-:eel %aft4 ,"s ef=ts h be5 made to prev5t leakage by =m+ grooves 9 ! sides ( ! revolv+ pi/on & fill+ !m ) s(t pack+4 ,sundry o!r rot>y eng9es1 "s ( !m actual work+ models1 are to be se5 at ! ,s\? ,k5s+ton ,museum4 ,!re is1 = example1 "o inv5t$ by ! ,rev4 ,patrick ,bell1 a g5tleman o!rwise kn[n to fame z "o ( ! e>lie/ inv5tors ( a practical reap+ ma*9e4 ,9 ?is app>atus1 ,a metal disc is secur$ to a horizontal axis c>ri$ 9 be>+s1 & ! l[] half ( ! disc is enclos$ by a *amb] ( circul> section hav+ its axis a semi-circle4 ,"o end ( ?is *amb] is clos$ & provid$ ) a pipe ?r\gh :i* /eam ent]s1 ! exhau/ tak+ place ?r\gh ! op5 end4 ,! disc is provid$ ) ?ree holes1 ea* fitt$ ) a circul> plate turn+ on an axis radial to ! disc1 & ^! plates :5 set at "r angles to ! disc become pi/ons 9 ! l[] enclos+ *amb]4 ,too!d ge>+ is arrang$ to rotate ^! pi/ons into ! plane ( ! disc on leav+ ! cyl9d] & back aga9 imm$iately aft] ent]+1 lock+ lev]s reta9+ !m 9 position dur+ ! int]vals4 ,! /eam pressure ^u ^! pi/ons =ces ! disc r\nd1 b ! eng9e is non-expansive1 & al?\gh "s provision = pack+ has be5 made1 ! leakage mu/ h be5 consid]able & ! we> & te> excessive4 ,x is /at$ t almo/ ! same arrangem5t 0 propos$ by ,"l ,arm/rong 9 #ahch z a wat] motor1 & t a model subsequ5tly con/ruct$ gave ov] five horse-p[] at ?irty revolutions p] m9ute1 ) an effici5cy ( n9ety-five p] c5t4 ,ano!r work+ model ( a rot>y eng9e %[n at ! ,museum is "o loan$ by ,messrs4 ,field+ & ,platt 9 #ahhh4 ,! action ( ?is eng9e dep5ds ^u ! oscillat+ motion :i* ! cross ( a univ]sal jo9t has relative to ! conta9+ jaws :5 ! sy/em is rotat$4 ,two %afts are set at an angle ( #afe deg4 to ea* o!r & connect$ by a ,hooke's jo9t2 "o s]ves z a pivot1 ! p[] be+ tak5 f ! o!r4 ,f\r curv$ pi/ons are arrang$ on ! cross-piece1 two po9t+ t[>ds "o %aft & two t[>ds ! o!r1 & on ea* %aft or jaw are =m$ two curv$ /eam cyl9d]s 9 :i* ! curv$ pi/ons "w4 ,! /eam ent]s & leaves ! base ( ea* cyl9d] ?r\gh ports 9 ! %aft1 :i* =ms a cyl9drical valve work+ 9 ! be>+ z a seat+4 ,on ! revolution ( ! %afts ! pi/ons reciprocate 9 _! cyl9d]s 9 mu* ! same way z 9 an ord9>y eng9e1 & ! valve arrangem5t is su* t :ile ea* pi/on is rec$+ f its cyl9d] ! /eam pressure is driv+ x1 & dur+ ! 9-/roke ( ea*1 its cyl9d] is 9 communication ) ! exhau/4 ,!re are ?us f\r s+le-act+ cyl9d]s mak+ ea* a d\ble /roke = "o revolution ( ! driv+-%aft4 ,! eng9e has no dead c5tres1 & has be5 at #a1jjj revolutions p] m9ute4 ,illu/ration3 ,,rot>y ,,eng9es4 ,! ?ree types ( rot>y eng9es "h %[n are simil> 9 pr9ciple1 & none ( !m is ( great practical value1 ?\gh ! upp] figure %[s an eng9e t has met ) a c]ta9 measure ( comm]cial success4 ,x is n necess>y to describe o!r ( ! rot>y eng9es t h be5 made along m or less simil> l9es by num]\s inv5tors1 models ( :i* are = ! mo/ "p1 z 9 ! case ( ^? j describ$1 to be se5 m commonly 9 museums ?an 9 practical work%ops4 ,ref]5ce may be made1 h[ev]1 to a rot>y eng9e :i* 0 inv5t$ by a ,mr4 ,h(fman1 ( ,buffalo1 ,new ,york1 ab\t ! beg9n+ ( ! tw5tie? c5tury1 an example ( :i* 0 put into actual op]ation 9 runn+ ! ma*9]y ( a %op 9 ,buffalo1 9 #aije4 ,?is eng9e consi/s ( a solid elliptical %aft ( /eel1 fa/5$ to an axle at "o side ( its c5tre1 :i* axis is also ! %aft ( ! cyl9d]1 :i* revolves ab\t ! c5tral ellipse 9 su* a way t at "o "p ( ! revolution ! cyl9d] surface fits tightly aga9/ ! ellipse1 :ile ! opposite side ( ! cyl9d] supplies a free *amb] betwe5 ! ellipse & ! cyl9d] walls4 ,runn+ ! l5g? ( ! cyl9d] are two curv$ pieces ( /eel1 l longitud9al sections ( a tube4 ,^! flanges are adju/$ at opposite sides ( ! cyl9d] & s arrang$ t _! sides at all times press aga9/ ! ellipse1 alt]nately retreat+ into ! sub/ance ( ! cyl9d]1 & com+ out into ! free *amb]4 ,/eam is admitt$ to ! free *amb] ?r\gh "o end ( ! %aft ( ellipse & cyl9d] & exhau/$ ?r\gh ! o!r end4 ,! pressure ( ! /eam aga9/ fir/ "o end & !n ! o!r ( ! flanges supplies ! motive p[]4 ,?is pressure acts always 9 "o direction1 & ! entire app>atus revolves1 ! cyl9d]1 h[ev]1 revolv+ m rapidly ?an ! c5tral ellipse4 ,= ?is eng9e ! extravagant claim is made t !re is no limit to its spe$ ( revolution1 )9 ! limit ( resi/ance ( /eel to c5trifugal =ce4 ,x has be5 e/imat$ t a locomotive might be made to run two hundr$ or ?ree hundr$ miles an h\r )\t difficulty1 ) ! ,h(fman eng9e4 ,su* e/imates1 h[ev]1 are !oretical1 & x rema9s to be se5 :at ! eng9e c d 9 practise :5 appli$ to a v>iety ( tasks1 & :at are its limitations4 ,c]ta9ly ! app>atus is at once +5i\s & simple 9 pr9ciple1 & !re is no obvi\s !oretical reason :y x %\ld n h an important future4 ,,turb9e ,,eng9es ,:atev] ! future may hold1 h[ev]1 x rema9s true t ! fir/ practical solution ( ! problem ( secur+ direct rot>y motion f ! action ( /eam1 on a really comm]cial scale1 0 solv$ ) an app>atus v diff]5t f any ( ^? j describ$1 ! inv5tor be+ an ,engli%man1 ,mr4 ,c4 ,a4 ,p>sons1 & ! app>atus ! /eam turb9e1 ! fir/ model ( :i* he con/ruct$ 9 #ahhd1 & :i* began to attract g5]al att5tion 9 ! c\rse ( ! ensu+ decade4 ,public int]e/ 0 fully ar\s$ 9 #ahig1 :5 ,mr4 ,p>son's boat1 ! ,turb9ia1 equipp$ ) eng9es ( ?is type1 %[$ a trial spe$ ( #cb-c_/d knots p] h\r1 a spe$ nev] hi!rto atta9$ by any o!r species ( wat] craft4 ,m rec5tly1 a torp$o boat1 ! ,vip]1 equipp$ ) eng9es develop+ ab\t t5 ?\s& horse-p[]1 atta9$ a spe$ ( #ce-a_/b knots4 ,! success ( ^! small boats l$ to ! equipm5t ( l>ge vessels ) ! turb9e1 & on ,april fir/1 #aije1 ! fir/ transatlantic l9] propell$ by ?is =m ( eng9e /eam$ into ! h>bor ( ,halifax1 ,nova ,scotia4 ,?is fir/ ocean l9] equipp$ ) ! turb9e eng9e is call$ ! ,victorian4 ,%e is a %ip five hundr$ & =ty feet long & sixty feet wide1 c>ry+ fifte5 hundr$ pass5g]s4 ,! ,victorian _h %[n a spe$ ( #ai-a_/b knots an h\r on h] trial trip1 & x _h be5 hop$ t %e w\ld break ! transatlantic record4 ,on h] fir/ trip1 h[ev]1 %e enc\nt]$ adv]se w9ds & seas1 & did n atta9 great spe$4 ,h] p]=mance 01 h[ev]1 consid]$ entirely satisfactory & cr$itable4 ,9 ! ensu+ half-decade sev]al l>ge %ips 7 equipp$ ) eng9es ( ! same type1 ! mo/ fam\s ( ^! be+ ! ,cun>d l9]s1 ,c>mania1 ,lusitania1 & ,mauretania4 ,! two la/-nam$ %ips are si/] craft1 & !y are ! l>ge/ boats ( any k9d hi!rto con/ruct$4 ,! ,lusitania 0 fir/ laun*$ & %e ent]$ imm$iately ^u a record-break+ c>e]1 only to be surpass$ )9 a few mon?s by ! ,mauretania1 :i* soon acquir$ all records = spe$ & endurance4 ,full] details z to ! p]=mance ( ^! vessels w be f\nd 9 ano!r place4 ,"h we are ( c\rse conc]n$ ) ! ,p>sons turb9e eng9e itself r ?an ) its applications4 ,?is turb9e eng9e con/itutes ! fir/ really important dep>ture f ! old-type /eam eng9e1 ?us realiz+ ! dream ( ! sev5te5?-c5tury ,italian1 ,branca1 to :i* ref]5ce 0 made above4 ,mr4 ,p>sons' elaboration ( ! idea develop$ a good deal ( complexity z reg>ds ! numb] ( p>ts involv$1 yet 8 eng9e is ( ! utmo/ simplicity 9 pr9ciple4 ,x consi/s ( a l>ge numb] ( s]ies ( small blades1 ea* s]ies arrang$ ab\t a drum :i* revolves4 ,betwe5 ! r+s ( revolv+ blades are adju/$ correspond+ r+s ( fix$ blades1 :i* project f ! cas+ to ! cyl9d]1 & by means ( :i* ! /eam is regulat$ 9 direction1 s t x /rikes at ! prop] angle aga9/ ! revolv+ blades ( ! turb9e4 ,9 practise1 ?ree s]ies ( cyl9drical drums are us$1 ea* conta9+ a l>ge numb] ( r+s ( blades ( uni=m size2 b ea* successive drum hav+ long] blades1 to accommodate ! great] volume ( ! exp&+ /eam4 ,! /eam is f$ aga9/ ! fir/ s]ies ( blades 9 gu/s1 :i* may be v>i$ 9 frequ5cy & l5g? to meet ! requirem5ts ( spe$4 ,aft] imp++ on ! fir/ circle ( blades1 ! /eam passes to ! next "u slightly r$uc$ pressure1 & ! pressure is ?us successively /epp$ d[n f "o set ( blades to ano!r until x is ultimately r$uc$ f say two hundr$ p\nds to ! squ>e in*1 to "o p\nd to ! squ>e in* be=e x passes to ! cond5s] & ceases to act4 ,!re is ?us a full] utilization ( ! k9etic en]gy ( ! gas1 ?r\gh c>ry+ x f high to l[ pressure1 ?an is possible ) ! old type ( cyl9d]-&-pi/on eng9e4 ,on ! o!r h&1 !re is a con/ant loss due to ! fact t ! blades ( ! turb9e c n fit ) absolute tightness aga9/ ! cyl9d] walls4 ,! net result is t ! comp\nd turb9e1 z at pres5t develop$1 appe>s to h ab\t ! same effici5cy z ! be/ eng9e ( ! old type4 ,"o capital advantage ( ! turb9e is t x keeps ! cyl9d] walls at a m uni=m temp]ature ?an is possible ev5 ) a comp\nd eng9e ( ! old type4 ,ano!r advantage is t ! p[] ( ! turb9e is appli$ directly to cause rotation ( ! %aft1 :]eas no satisfactory means has ev] be5 discov]$ hi!rto ( mak+ ! action ( ! /eam eng9e rot>y1 except ) ! some:at disadvantage\s crank-%aft4 ,?is fact ( adju/m5t ( ! turb9e blades to ! revolv+ %aft seems to make ?is =m ( eng9e p>ticul>ly adapt$ to use 9 /eam%ips4 ,x is also highly adapt$ to revolv+ ! %aft ( a dynamo1 & has be5 l>gely appli$ to ?is use4 ,ne$less to say1 h[ev]1 x may be appli$ to any o!r =m ( ma*9]y4 ,x w\ld be difficult at ! pres5t /age ( its developm5t to pr$ict ! ext5t to :i* ! turb9e w ultimately sup]s$e ! old type ( eng9e4 ,its progress has already be5 extraord9>y1 h[ev]1 z an eng9e] po9t$ out 9 ! ,london ,times ( ,augu/ #ad1 #aijg1 9 ! foll[+ words3 ,:5 ! /eam turb9e 0 introduc$ by ,mr4 ,p>sons "s #be ye>s ago1 9 ! =m ( a little model1 :i* is n[ 9 ! ,s\? ,k5s+ton ,museum1 & ! rotor ( :i* may easily be held /ation>y by ! h& aga9/ ! full bla/ ( ! /eam1 :o w\ld h be5 ra% en\gh to pr$ict1 except p]haps ! f>-see+ inv5tor himself1 t a vessel #gfj feet long1 load$ to #cg1jjj tons displacem5t1 draw+ #cb ft4 #i 94 ( wat]1 & provid+ accommodation = #b1ejj p1 c\ld be propell$ at a spe$ ( #bd4e knots p] h\r1 :i* x is hop$ %e may ma9ta9 ov] ! #c1jjj miles ( ! ,atlantic voyage8 ,f ?is small model1 :i* w 9 "t become z hi/oric z ! ,rocket ( ,/eph5son1 & :i* is only "s few in*es 9 diamet]1 ! turb9e has be5 develop$ gradually 9 size4 ,! cyl9drical cas+s :i* take ! place ( ! complicat$ ma*9]y ( ! pi/on eng9e 9 ! eng9e room ( ! ,lusitania conta9 drums1 :i* 9 ! high-pressure turb9es are #h feet 9 diamet] & 9 ! l[-pressure #aa ft4 #h 941 & f :i* ?\s&s ( curv$ blades project1 ! longe/ ( :i* are #bb in*es1 & aga9/ :i* ! /eam imp+es 9 its c\rse f ! boil] to ! cond5s]4 ,n only has ! /eam turb9e ju/ifi$ ! confid5ce ( ^? :o h labor$ s successfully 9 its developm5t1 b no o!r great inv5tion has proce$$ f ! laboratory /age to su* an important position 9 ! eng9e]+ _w 9 su* a %ort space ( "t4 ,?is w\ld n h happ5$ if "s inh]5t drawback1 su* z lack ( economy 9 /eam consumption1 exi/$1 & z ! turb9e has be5 prov$ to be1 = l& purposes1 v economical1 !re seems to be no reason to d\bt t m>9e turb9es1 work+ z !y d at full load almo/ cont9ually1 w %[ likewise t ! coal bill is n increas$1 b p]haps dim9i%$ by _! use4 ,! records ( ! vibrations ( ! hull :i* 7 tak5 dur+ ! trials by ,s*lick's in/rum5ts %[$ t ! v]tical vibration 0 #fj p] m9ute on ! run1 :i* 0 due to ! propell]s1 & :i* may be fur!r modifi$4 ,! horizontal vibration 0 almo/ unnoticeable1 :ile ! behavior ( ! %ip 9 ! heavy seas %e enc\nt]$ 9 h] long-di/ance runs 0 good1 ! roll f side to side hav+ a p]iod ( #ah seconds4 ,! great l5g? ( ?is %ip & ! gyro/atic action ( ! heavy rotat+ masses ( ! ma*9]y ought to r5d] h] almo/ ins5sible to ! heavie/ ,atlantic roll]s2 c]ta9ly z f> z pit*+ is conc]n$4 ,illu/ration3 ,,! ,,orig9al ,,p>son',s ,,turb9e ,,eng9e ,,& ,,! ,,record-,,break+ ,,%ip ,,= ,,:i* ,,x ,,is ,,responsible4 ,?is small turb9e eng9e1 ) :i* ,mr4 ,p>son's e>ly exp]im5ts 7 made 9 #ahhd1 is pres]v$ 9 ! ,s\? ,k5s+ton ,museum1 ,london4 ,at ! "t :5 x 0 made x seem$ sc>cely m ?an a toy1 & eng9e]s 9 g5]al d\bt$ t ! pr9ciple x employ$ c\ld ev] be made comm]cially available4 ,yet )9 ! lifetime ( its inv5tor eng9es built on ?is model h come to be ! mo/ p[]ful ( =ce transmut]s4 ,! ,mauretania1 ! l>ge/1 & ?anks to h] turb9e eng9es ! spe$ie/1 ( %ips1 is "h pres5t$ on ! same page ) ! little orig9al turb9e model1 z illu/rat+ vividly ! practical developm5t ( a seem+ly vision>y idea4 ,a m g5]al comm5t ^u ! turb9e eng9e1 ) p>ticul> ref]5ce to its use 9 ,am]ica1 is made by ,mr4 ,edw>d ,h4 ,sanborn 9 an article on ,motive ,p[] ,appliances1 9 ! ,twelf? ,c5sus ,report ( ! ,unit$ ,/ates1 ,vol4 ,x4 "p ,,iv4 ,ap>t f its demon/rat$ economy1 says ,mr4 ,sanborn1 o!r important advantages are claim$ = ! /eam turb9e1 "s ( :i* are wor?y ( brief m5tion4 ,!re is an obvi\s advantage 9 economy ( space z comp>$ ) ! reciprocat+ eng9e4 ,! l>ge/ /eam turb9e con/ruct$ 9 ! ,unit$ ,/ates is "o ( #c1jjj horse-p[]1 :i* is in/all$ 9 ! p[] h\se ( ! ,h>t=d ,electric ,light ,company1 ,h>t=d1 ,conn4 ,! total weight ( ?is motor is #bh1jjj p\nds1 its l5g? ov] all is #ai feet #h in*es1 & its greate/ diamet] six feet4 ,) ! g5]ator to :i* x is directly connect$1 x occupies a floor space ( #cc feet #c in*es long by #h feet #i in*es wide4 ,friction is r$uc$ to a m9imum 9 ! /eam turb9e1 ow+ to ! abs5ce ( slid+ p>ts & ! small numb] ( be>+s4 ,! abs5ce ( int]nal lubrication is also an important consid]ation1 especially :5 x is desir$ to use cond5s]s4 ,z !re are no reciprocat+ p>ts 9 a /eam turb9e1 & z a p]fect balance ( its rotat+ p>ts is absolutely ess5tial to its successful op]ation1 vibration is r$uc$ to su* a small elem5t t ! simple/ f\ndations w suffice1 & x is safe to locate /eam turb9es on upp] floors ( a factory if ?is be desirable or necess>y4 ,! p]fect balance ( ! mov+ p>ts & ! extreme simplicity ( con/ruction t5d to m9imize ! we> & increase ! life ( a turb9e1 & at ! same "t to r$uce ! *ance ( int]ruption 9 its op]ation ?r\gh d]angem5t (1 or damage to1 any ( its ess5tial p>ts4 ,al?\gh h>dly beyond ! /age ( its fir/ adv5t 9 ! motive-p[] field1 ! /eam turb9e has met ) mu* favor1 & !re is promise ( its wide use = ! purposes to :i* x is p>ticul>ly adapt$4 ,at pres5t1 h[ev]1 its uses are re/rict$ to s]vice t is cont9u\s & regul>1 its p>ticul> adaptability be+ = ! driv+ ( electrical g5]ators1 pumps1 v5tilat+ fans1 & simil> "w1 especially :]e />t+ "u load is n ess5tial4 ,/eam turb9es are n[ be+ built 9 ! ,unit$ ,/ates 9 all sizes up to #c1jjj horse-p[]4 ,_! use abroad cov]s a long] p]iod & has become m g5]al4 ,! l>ge/ turb9es ?us f> attempt$ are ^? ( ! ,metropolitan ,di/rict ,electric ,traction ,company1 ( ,london1 embrac+ f\r units ( #aj1jjj horse-p[] ea*4 ,sev]al turb9es ( l>ge size h be5 op]at$ successfully 9 ,g]many4 ,x %\ld be add$ t ! comp\nd turb9e :eel ( ,p>sons is n ! only turb9e :eel t has prov$ comm]cially valuable4 ,!re is a turb9e consi/+ ( a s+le r+ ( revolv+ blades1 ! inv5tion ( ,dr4 ,gu/av ,de ,laval1 :i* has prov$ itself capable ( compet+ ) ! old type ( eng9e4 ,to make ?is =m ( s+le turb9e op]ate satisfactorily1 x is necess>y to h /eam "u high pressure1 & to g5]ate a v high spe$ ( revolution4 ,9 practice1 ! ,de ,laval ma*9es sometimes atta9 a spe$ ( ?irty ?\s& revolutions p] m9ute4 ,?is is a mu* high] rate ( spe$ ?an c advantage\sly be utiliz$ directly 9 ord9>y ma*9]y1 & consequ5tly ! %aft ( ?is ma*9e is ge>$ to ano!r %aft 9 su* a way z to cause ! second %aft to revolve mu* m sl[ly4 ,,vii ,,gas ,,& ,,oil ,,eng9es ,j at ! "t :5 ! type ( pi/on-&-cyl9d] eng9e has ?us be5 *all5g$1 x has *anc$ t a new motive p[] has be5 appli$ to ! old type ( eng9e1 ?r\gh ! m$ium ( heat$ gas4 ,! idea ( su* utilization ( a gas o!r ?an wat] vapor is by no means new1 b !re h be5 practical difficulties 9 ! way ( ! con/ruction ( a comm]cial eng9e to make use ( ! expansive p[] ( ord9>y gases4 ,! pr9ciple involv$ is bas$ on ! famili> fact t a gas exp&s on be+ heat$ & contracts :5 cool4 ,!oretically1 !n1 all t is necess>y is to heat a portion ( air conf9$ 9 a cyl9d]1 to secure ! advantage ( its expansion1 precisely z ! expansion ( /eam is utiliz$1 by ?ru/+ =w>d a pi/on4 ,su* an app>atus con/itutes a s-call$ caloric or hot-air eng9e4 ,z long ago z ! ye> #ahjg ,sir ,g4 ,cayley 9 ,engl& produc$ a motor ( ?is type1 9 :i* ! heat$ air pass$ directly f ! furnace to ! cyl9d]1 :]e x did "w :ile exp&+ until its pressure 0 n great] ?an t ( ! atmosph]e1 :5 x 0 dis*>g$4 ,! *ief me*anical difficulty enc\nt]$ result$ f ! necessity = ! employm5t ( v high temp]atures2 & = a long "t ! eng9e _h no great comm]cial utility4 ,! idea 0 reviv$1 h[ev]1 ab\t ?ree-qu>t]s ( a c5tury lat] & an eng9e op]at$ on ,cayley's pr9ciple 0 comm]cially introduc$ 9 ,engl& by ,mr4 ,buckett4 ,?is eng9e has a cold-air cyl9d] above ! crank-%aft & a l>ge hot-air cyl9d] bel[1 :ile ! furnace is on "o side enclos$ 9 an air-tight *amb]4 ,! fuel is suppli$ z requir$ ?r\gh a valve & di/ribut+ cone arrang$ above ! furnace & provid$ ) an air lock 9 :i* ! fuel is /or$4 ,at ab\t ! "t :5 ?is hot-air eng9e 0 introduc$1 h[ev]1 gas & oil eng9es ( ano!r & m important type 7 develop$1 z we %all see 9 a mom5t4 ,meantime1 an int]e/+ ef=t to utilize ! expansive prop]ty ( heat$ air 0 made by ,dr4 ,/irl+ 9 #ahbf2 8 eng9e be+ "o 9 :i* heat 0 di/ribut$ by means ( a displac] :i* mov$ ! mass ( air to & fro betwe5 ! hot & cold portions ( ! app>atus4 ,he also compress$ ! air be=e heat+ x1 ?us mak+ a di/9ct advance 9 ! economy & compactness ( ! eng9e4 ,f an eng9e]+ /&po9t 8 design has fur!r int]e/ 9 t x 0 a practical attempt to con/ruct an eng9e work+ on ! pr9ciple ( ! !oretically p]fect heat eng9e1 9 :i* ! cycle ( op]ations is clos$1 ! same mass ( air be+ us$ ?r\gh\t4 ,9 ! !oretically p]fect heat eng9e1 x may be add$1 ! cycle ( op]ations may be rev]s$1 !re be+ no loss ( en]gy involv$2 b 9 practice1 ( c\rse1 an eng9e _c be con/ruct$ to meet ?is ideal condition1 z !re is necess>ily "s loss ?r\gh dissipation ( heat4 ,dr4 ,/irl+'s practical eng9e _h its uses1 b c\ld n compete ) ! /eam eng9e 9 ! g5]al field ( me*anical op]ations to :i* t app>atus is appli$4 ,ano!r important practical exp]im5t] 9 ! con/ruction ( hot-air eng9es 0 ,john ,ericsson1 :o 9 #ahbd con/ruct$ an eng9e some:at resembl+ ! e>ly "o ( ,cayley1 & 9 #aheb built caloric eng9es on su* a scale z to be adapt$ to ! propulsion ( %ips4 ,not)/&+ ! g5ius ( ,ericsson1 h[ev]1 eng9es ( ?is type did n prove comm]cially successful on a l>ge scale1 & 9 subsequ5t decades ! hot-air motors con/ruct$ = practical purposes seldom exce$$ "o horse-p[]4 ,su* small eng9es z ^! are comp>atively effici5t & absolutely safe1 & !y are ?or\ghly adapt$ = su* dome/ic purposes z light pump+4 ,! great difficulty ) all ^! eng9es op]at$ ) heat$ air has be51 z already sugge/$1 t _! effici5cy ( action is limit$ by ! difficulties incid5t to apply+ high temp]atures to l>ge masses ( ! gas4 ,!re is1 h[ev]1 no objection to ! sup]-heat+ ( small quantities ( gas1 & x 0 e>ly sugge/$ t ?is might be accompli%$ by explod+ a gase\s mixture )9 a cyl9d]4 ,x 0 obs]v$ by ! exp]im5t]s ( ! sev5te5? c5tury t an ord9>y gun con/itutes virtually an int]nal-combu/ion eng9e2 & su* exp]im5t]s z ! ,dut*man ,huygh5s1 & ! ,fr5*m5 ,hautefeuille & ,pap91 attempt$ to make practical use ( ! p[] set free by ! explosion ( gunp[d]1 _! exp]im5ts be+ conduct$ ab\t ! ye>s #afgh to #afhi4 ,_! results1 h[ev]1 7 n su* z to give !m o!r ?an an hi/orical int]e/4 ,ab\t a c5tury lat]1 9 #agid1 ! ,engli%man ,rob]t ,/reet sugge/$ ! use ( inflammable gases z explosives1 & ev] s9ce t "t !re h be5 occasional exp]im5t]s along t l9e4 ,9 #ahbc ,samuel ,br[n introduc$ a vacuum gas eng9e = rais+ wat] by atmosph]ic pressure4 ,! fir/ fairly practical gas eng9e1 h[ev]1 0 t introduc$ by ,j4 ,j4 ,e4 ,l5oir1 :o 9 #ahej propos$ an eng9e work+ ) a cycle resembl+ t ( a /eam eng9e4 ,8 eng9e pat5t$ 9 #ahfj prov$ to be a fairly successful app>atus4 ,?is eng9e ( ,l5oir prep>$ ! way = gas eng9es t h s9ce become s enorm\sly important4 ,its me?od ( action is ?is3 ,to />t ! eng9e1 ! fly-:eel is pull$ r\nd1 ?us mov+ ! pi/on1 :i* draws into ! cyl9d] a mixture ( gas & air ?r\gh ab\t half its /roke2 ! mixture is !n explod$ by an electric sp>k1 & propels ! pi/on to ! end ( its /roke1 ! pressure mean:ile fall+1 by cool+ & expansion1 to t ( ! atmosph]e :5 exhau/ takes place4 ,9 ! return /roke ! process is repeat$1 ! action ( ! eng9e resembl+ t ( ! d\ble-act+ /eam eng9e1 & hav+ a "o-/roke cycle4 ,! cyl9d] & cov]s are cool$ by circulat+ wat]4 ,! fir+ electricity 0 suppli$ by two ,buns5 batt]ies & an induction coil1 ! circuit be+ complet$ at ! "r int]vals by contact pieces on an insulat+ disc on ! crank-%aft2 ! ignition sp>k leap$ across ! space betwe5 two wires c>ri$ ab\t "o-six? ( an in* ap>t 9 a porcela9 hold]4 ,9 #ahfe ,mons4 ,p4 ,hugon pat5t$ an eng9e simil> to t ( ,l5oir1 except t ignition 0 accompli%$ by an ext]nal flame in/ead ( by electricity4 ,! ignition flame 0 c>ri$ to & fro 9 a cavity inside a slide valve1 mov$ by a cam s z to get a rapid cut-(f1 & p]man5t lights 7 ma9ta9$ at ! ends ( ! valve to re-light ! flame-ports aft] ea* explosion4 ,! gas 0 suppli$ to ! cyl9d] by rubb] bell[s1 work$ by an ecc5tric on ! crank-%aft4 ,?is eng9e c\ld be op]at$ satisfactorily1 except z to co/1 b ! heavy gas consumption made x uneconomical4 ,an important improvem5t 9 ?is reg>d 0 introduc$ by ! ,g]mans1 ,h]rn4 ,e4 ,lang5 & ,n4 ,a4 ,otto1 :o "u pat5ts be>+ date ( #ahff introduc$ a s-call$ free pi/on arrangem5t--t is to say an arrangem5t by :i* ! pi/on dep5ds = its action p>tly ^u ! mom5tum ( a fly-:eel4 ,?is pr9ciple _h be5 propos$ = a gas eng9e z e>ly z #aheg1 b ! fir/ ma*9e to demon/rate its feasibility 0 t ( ,lang5 & ,otto4 ,_! eng9e greatly decreas$ ! gas consumption & h5ce came to be reg>d$ z ! fir/ comm]cially successful gas eng9e4 ,x 01 h[ev]1 noisy & limit$ to small sizes4 ,! cycle ( op]ations ( an eng9e ( ?is type is describ$ z foll[s3 ,illu/ration3 ,,gas ,,& ,,oil ,,eng9es4 ,l[] "r-h& figure1 a v e>ly type ( comm]cially successful gas eng9e4 ,x has a free pi/on1 an arrangem5t t 0 fir/ propos$ = a gas eng9e 9 #aheg1 b only br\ght into practical =m by ,lang5 ,otto "u _! pat5t ( #ahff4 ,upp] figure1 ! gas eng9e pat5t$ by ,l5oir 9 #ahfj1 "o ( ! v fir/ practically successful eng9es4 ,l[] left-h& figure1 a sectional view ( a mod]n gas eng9e ( ! type us$ z ! motor ( ! automobile4 7a7 ,! pi/on is lift$ ab\t "o-t5? ( its travel by ! mom5tum ( ! fly-:eel1 ?us draw+ 9 a *>ge ( gas & air4 7b7 ,! *>ge is ignit$ by flame c>ri$ 9 by a slide valve4 7c7 ,"u ! impulse ( ! explosion1 ! pi/on %oots upw>d ne>ly to ! top ( ! cyl9d]1 ! pressure 9 :i* falls by expansion to ab\t #d lbs4 absolute1 :ile absorb+ ! en]gy ( ! pi/on4 7d7 ,! pi/on desc5ds by its own weight & ! atmosph]ic pressure1 & 9 do+ s causes a roll]-clut* on a spur-:eel ge>+ ) a rack on ! pi/on-rod to engage1 s t ! fly-:eel %aft %all be driv5 by ! pi/on2 dur+ ?is d[n-/roke ! pressure increases f #d lbs4 absolute to t ( ! atmosph]e1 & av]ages #g lbs4 p] squ>e in* effective ?r\gh\t ! /roke4 7e7 ,:5 ! pi/on is ne> ! bottom ( ! cyl9d]1 ! pressure rises above atmosph]ic1 & ! /roke is complet$ by ! weight ( ! pi/on & rack1 & ! products ( combu/ion are expell$4 7f7 ,! fly-:eel n[ cont9ues runn+ freely till its spe$1 z det]m9$ by a c5trifugal gov]nor1 falls bel[ a c]ta9 limit :5 a trip ge> causes ! pi/on to be lift$ ! %ort di/ance requir$ to recomm5ce ! cycle4 ,ignition is p]=m$ by an ext]nal gas jet1 ne> a pocket 9 ! slide valve by :i* ! *>ge is admitt$2 ?is pocket c>ries flame to ! *>ge1 ?us ignit+ x )\t all[+ any escape4 ,! valve also connects ! int]ior ( ! cyl9d] ) ! exhau/ pipe1 & a valve 9 ! latt] controll$ by ! gov]nor ?rottles ! dis*>ge1 & s def]s ! next /roke until ! spe$ has fall5 bel[ normal4 ,to run ! eng9e empty ab\t f\r explosions p] m9ute are necess>y1 & at full p[] #cj to #ce are made1 s t ab\t #bh explosions p] m9ute are available = useful "w "u ! control ( ! gov]nor4 ,! def9itive improvem5t 9 ?is gas eng9e 0 introduc$ 9 #ahgf by ,dr4 ,n4 ,a4 ,otto1 :5 he compress$ ! explosive mixture 9 ! work+ cyl9d] be=e ignit+ x4 ,?is exp$i5t--s all-important 9 its results--_h be5 sugge/$ by ,william ,b>nett 9 #ahch1 b at t "t gas eng9es 7 n suffici5tly develop$ to make use ( ! idea4 ,n[1 h[ev]1 ,dr4 ,otto demon/rat$ t by compress+ ! gas be=e explod+ x a mu* m dilut$ mixture c be fir$1 & t ?is gives a quiet] explosion1 & a m su/a9$ pressure dur+ ! work+ /roke1 :ile z ! eng9e runs at a high spe$ ! fly-:eel action is g5]ally suffici5t to correct ! fluctuations aris+ f !re be+ b "o explosion = f\r /rokes ( ! pi/on4 ,9 ?is p]fect$ eng9e1 !n1 ! me?od ( op]ation is z foll[s3 ,! pi/on is pull$ =w>d ) ! application ( "s outside =ce1 :i* 9 practice is suppli$ by ! in]tia ( ! fly-:eel1 or 9 />t+ ! eng9e by ! action ( a crank ) :i* e us] ( an automobile is famili>4 ,9 be+ pull$ =w>d1 ! pi/on draws gas into ! cyl9d]2 z ! pi/on returns1 ?is gas is compress$2 ! compress$ gas1 con/itut+ an explosive mixture1 is !n ignit$ by a piece ( inc&esc5t metal or by an electric sp>k2 ! explod+ gas exp&s1 pu%+ ! pi/on =w>d1 ?is be+ ! only ?ru/ dur+ :i* "w is done2 ! return+ pi/on expels ! exp&$ gas1 complet+ ! cycle4 ,?us !re are ?ree ineffective pi/on ?ru/s to "o effective ?ru/4 ,nev]!less1 ! eng9e has prov$ a useful "o = _m purposes4 ,?is s-call$ ,otto cycle has be5 adopt$ 9 almo/ all gas & oil eng9es1 ! lat] improvem5ts be+ 9 ! direction ( /ill high] compression1 & 9 ! sub/itution ( lift = slide valves4 ,!re has be5 a /eady increase 9 ! size & p[] ( su* eng9es1 ! l>ge ones usually introduc+ two or m work+ cyl9d]s s z to secure uni=m driv+4 ,*eap =ms ( gas h be5 employ$ su* z ^? made by decompos+ wat] by inc&esc5t fuel1 & x has be5 prov$ possible ?us to op]ate gas-p[] plants on a comm]cial scale 9 competition ) ! mo/ economical /eam in/allations4 ,a practical modification ( va/ importance 0 introduc$ :5 x 0 sugge/$ t a volatile oil be employ$ to supply ! gas = op]ation 9 an int]nal combu/ion eng9e4 ,!re 0 no new pr9ciple involv$ 9 ?is idea1 & ! ,otto cycle 0 /ill employ$ z be=e2 b ! use ( ! volatile oil--ei!r a petroleum product or alcohol--made possible ! compact portable eng9e ) :i* ev]yone is n[adays famili> ?r\gh its use 9 automobiles & motor boats4 ,! oil commonly us$ is gasol9e :i* is suppli$ to ! cyl9d] ?r\gh a s-call$ c>burettor 9 :i* ! vapors ( gasol9e are comb9$ ) ord9>y air to make an explosive mixture4 ,! introduction ( ?is n[ famili> type ( motor is to a l>ge ext5t due to ,h]r ,g4 ,daiml]1 :o 9 #ahhd br\ght out a light & compact high-spe$ oil eng9e4 ,ab\t t5 ye>s lat] ,messrs4 ,panh>d & ,levassor devis$ ! =m ( motor :i* has s9ce be5 g5]ally adopt$4 ,few o!r =ms ( me*anisms are bett] kn[n to ! g5]al public ?an ! oil eng9e ) its two1 f\r1 six1 or ev5 eight cyl9d]s1 z us$ 9 ! mod]n automobile4 ,z ev]yone is aw>e1 x furni%es ! favorite type ( motor1 comb9+ extraord9>y p[] ) relative lightness1 & mak+ x feasible to c>ry fuel = a long j\rney 9 a receptacle ( small compass4 ,) ! gas eng9es a complication arises precisely opposite to t :i* is met ) 9 ! case ( ! cyl9d] ( ! /eam eng9e--! t5d5cy1 namely1 to ov]heat+ ( ! cyl9d]4 ,to obviate ?is x is cu/om>y to h ! cyl9d] surr\nd$ by a wat] jacket1 ?\gh air cool+ is us$ 9 c]ta9 types ( ma*9es4 ,ab\t fifty p] c5t4 ( ! total heat o!rwise available is lo/ ?r\gh ?is unavoidable exp$i5t4 ,! rapid introduction ( ! gas eng9e 9 rec5t ye>s sugge/s t ?is type ( eng9e may h a mo/ important future4 ,x has ev5 be5 pr$ict$ t )9 a few ye>s mo/ trans-,atlantic /eam]s w be equipp$ ) ?is type ( eng9e1 produc+ _! own gas 9 transit4 ,x is possible1 !n1 t ?r\gh ?is m$ium ! old pi/on-&-cyl9d] eng9e may reta9 its supremacy1 z aga9/ ! turb9e4 ,= ! mom5t1 at any rate1 ! gas eng9e is ga9+ popul>ity1 n m]ely 9 its application to ! automobile1 b = num]\s types ( small /ation>y eng9es z well4 ,9 ?is connection x w be int]e/+ to quote ! report ( ! ,special ,ag5t ( ! ,twelf? ,c5sus ( ! ,unit$ ,/ates1 z %[+ ! /atus ( gas eng9es & /eam eng9es 9 ! ye> #aijb4 ,! decade betwe5 #ahij & #aijj1 he says1 0 a p]iod ( m>k$ developm5t 9 ! use ( gas eng9es1 us+ t t]m to d5ote all =ms ( int]nal combu/ible eng9es1 9 :i* ! propell+ =ce is ! explosion ( gase\s or vapor\s fuel 9 direct contact ) a pi/on )9 a clos$ cyl9d]4 ,?is gr\p embraces ^? eng9es us+ ord9>y illum9at+ gas1 natural gas1 & gas made 9 special produc]s in/all$ z a "p ( ! p[] plant1 & also vaporis$ gasol9e or k]os5e4 ,?is =m ( p[] = ! fir/ "t is an item ( consequ5ce 9 ! returns ( ! pres5t c5sus1 & ! v l>ge increase 9 ! horse-p[] 9 #aijj z comp>$ ) #ahij indicates ! gr[+ popul>ity ( ?is class ( motive p[]4 ,9 #ahij ! numb] ( gas eng9es 9 use 9 manufactur+ plants 0 n report$1 b _! total p[] am\nt$ to only #h1icj horse-p[]1 or "o-t5? ( "o p] c5t ( ! total p[] utiliz$ 9 manufactur+ op]ations4 ,9 #aijj1 h[ev]1 #ad1hhd gas eng9es 7 report$1 ) a total ( #adc1hej horse-p[]1 or #a4c p] c5t ( ! total p[] us$ = manufactur+ purposes4 ,?is increase f #h1icj horse-p[] to #adc1hej horse-p[]1 a ga9 ( #acd1ibj horse-p[]1 is proportionately ! l>ge/ increase 9 any =m ( prim>y p[] %[n by a comp>ison ( ! figures ( ! ,elev5? & ,twelf? c5suses1 am\nt+ to #a1eaj4i p] c5t4 ,)9 ! pa/ decade1 & m p>ticul>ly dur+ ! pa/ five ye>s1 !re has be5 a m>k$ increase 9 ! use ( ?is p[] 9 indu/rial e/abli%m5ts = driv+ ma*9]y1 = g5]at+ electricity1 & = o!r k9dr$ uses4 ,at ! same "t1 int]nal-combu/ion eng9es h increas$ 9 popul>ity = uses ap>t f manufactur+1 & ! am\nt ( ?is k9d ( p[] 9 use = all purposes 9 #aijj 01 d\btless1 v mu* l>g] ?an indicat$ by ! figures relat+ to manufactur+ plants alone4 ,! av]age horse-p[] p] gas eng9e 9 #aijj 0 #i4g horse-p[]4 ,!re are no available /ati/ics ^u :i* to base a comp>ison ( ?is av]age ) ! av]age = #ahij1 b x is d\btful if !re has be5 any v mat]ial *ange 9 t5 ye>s2 = :ile gas eng9es are built 9 mu* l>g] sizes ?an ev] be=e1 !re has be5 also a great increase 9 ! numb] ( small eng9es = v>i\s purposes4 ,! l>ge increase 9 ! use ( int]nal-combu/ion eng9es has be5 due to ! rapid improvem5ts t h be5 made 9 !m1 _! increas$ effici5cy & economy1 _! decreas$ co/1 & ! wid] range ( adaptability t has be5 made practicable4 ,/eam /ill cont9ues to be preem95tly ! p[] ( greate/ importance1 & ! c5sus returns indicate t ! proportion ( /eam to ! total ( all p[]s has increas$ v l>gely 9 ! pa/ ?irty ye>s4 ,9 #ahgj /eam furni%$ #a1bae1gaa horse-p[]1 or #ea4h p] c5t ( a total ( #b1cdf1adb2 9 #ahhj ! am\nt ( /eam p[] us$ 0 #b1ahe1deh horse-p[] out ( a total ( #c1daj1hcg1 or #fd4a p] c5t2 9 #ahij out ( an aggregate ( #e1ied1fee horse-p[]1 #d1eha1eie1 or #gf4i p] c5t 0 /eam2 :ile 9 #aijj /eam figur$ to ! ext5t ( #h1gdb1daf horse-p[]1 or #gg4d p] c5t1 9 a total ( #aa1cjj1jha4 ,?is increase 9 ?irty ye>s1 f #ea4h p] c5t to #gg4d p] c5t ( ! total p[]1 %[s h[ mu* m rapidly ! use ( /eam p[] has increas$ ?an o!r prim>y s\rces ( p[]4 ,! t5d5cy t[>d l>g] units 9 ! use ( /eam p[] is %[n inadequately by ! increase 9 ! av]age horse-p[] p] eng9e f #ci horse-p[] 9 #ahhj1 to #ea horse-p[] 9 #ahij1 & #ef horse-p[] 9 #aijj4 ,! t5d5cy t[>d great op]ations :i* has be5 su* a conspicu\s feature ( indu/rial progress dur+ ! pa/ t5 ye>s1 has %[n itself /rik+ly 9 ! use ( units ( l>g] capacity 9 ne>ly e =m ( ma*9]y1 & n[h]e has ?is t5d5cy be5 m m>k$ ?an 9 ! motive p[] by :i* ! ma*9]y is driv54 ,at ! same "t !re has be5 an increase 9 ! use ( small units1 :i* t5ds to de/roy ! true t5d5cy 9 /eam eng9e]+ 9 ^! /ati/ics4 ,= example1 a /eam plant consi/+ ( "o or m units ( sev]al ?\s& horse-p[] may also embrace a numb] ( small eng9es ( only a few horse-p[] ea*1 ! use ( :i* is necessitat$ by ! magnitude ( ! plant1 = ! op]ation ( me*anical /ok]s1 ! driv+ ( draft fans1 coal & a% conveyors1 & o!r "w requir+ p[] 9 small units4 ,on ?is acc\nt ! av]age horse-p[] ( /eam eng9es 9 use at diff]5t c5sus p]iods fails to af=d a true basis = measur+ progress t[>d l>g] units dur+ ! pa/ t5 ye>s4 ,developm5ts ( ! pa/ few ye>s 9 ! di/ribution ( p[] by ! use ( electric motors h s]v$ to accel]ate ! t5d5cy t[>d l>g] /eam units & ! elim9ation ( small eng9es 9 l>ge plants & to *ange completely ! conditions j describ$4 ,= example3 ,9 "o ( ! l>ge/ p[] plants 9 ! _w1 :i* is n[ be+ in/all$1 all ! /ok]s1 bl[]s1 conveyors1 & o!r auxili>y ma*9]y are to be driv5 by electric motors4 ,su* rapidly *ang+ conditions t5d to invalidate any comp>isons ( /ati/ical av]ages d$uc$ f figures = p]iods ev5 b a few ye>s ap>t4 ,comp>ison ( two important indu/ries w illu/rate ! =ego+4 ,! av]age horse-p[] ( ! /eam eng9e us$ 9 ! cotton mills ( ! ,unit$ ,/ates 9 #ahij 0 #aih1 & 9 #aijj x 0 #cjj4 ,9 ! iron & /eel indu/ry ! av]age horse-p[] p] eng9e 9 #ahij 0 #aga1 & 9 #aijj x 0 #bce4 ,9 ! cotton mills ! use ( s+le l>ge units ( motive p[]1 ) few auxili>y eng9es ( small capacity1 gives ! l>ge/ horse-p[] p] eng9e ( any indu/ry2 :ile 9 ! iron & /eel indu/ry ! av]age ( ! motive p[] prop]1 al?\gh probably l>g] ?an 9 ! manufacture ( cotton goods1 is r$uc$ by ! l>ge numb] ( small eng9es :i* are us$ = auxili>y purposes 9 e iron & /eel plant4 ,x w be und]/ood t ! object ( explod+ ! mix$ gases 9 ! oil eng9e is to produce sudd5 heat+ ( ! entire gas4 ,!re is no reason :atev] = introduc+ ! gasol9e beyond ?is4 ,c\ld a bett] me?od ( heat+ air be devis$1 ! oil might be entirely disp5s$ )1 & ! safety ( ! app>atus enhanc$1 z well z ! economy ( op]ation4 ,ef=ts h be5 made = fifty ye>s to con/ruct a hot-air eng9e t w\ld compete ) /eam successfully4 ,9 ! e>ly fifties1 z already not$1 ,ericsson %[$ ! feasibility ( sub/itut+ hot air = /eam1 b al?\gh he con/ruct$ l>ge eng9es1 _! p[] 0 s slight t he 0 oblig$ to give up ! idea ( compet+ ) /eam1 & to use 8 eng9es = pump+ :]e v small p[] 0 requir$4 ,! great difficulty 0 t x 0 n f\nd practicable to heat ! air rapidly4 ,all subsequ5t exp]im5t]s h met ) ! same difficulty until some:at rec5tly4 ,x is n[ claim$1 h[ev]1 t a means has be5 f\nd ( rapidly heat+ ! air1 & x is ev5 pr$ict$ t ! hot-air eng9e w 9 due c\rse entirely sup]s$e ! /eam eng9e4 ,mr4 ,g4 ,emil ,hesse1 9 an article 9 ,! ,am]ican ,inv5tor1 = ,april #ae1 #aije1 describes a ,svea caloric eng9e z hav+ successfully solv$ ! problem ( rapidly heat+ air4 ,! me?ods consi/ 9 break+ up ! air into ?9 lay]s & pass+ x ov] hot plates1 :]e x rapidly absorbs heat4 ,x passes f ! heat] to ! p[] cyl9d] :i* resembles ! cyl9d] ( a /eam eng9e2 !nce aft] exp&+ & do+ its "w x is exhau/$ into ! atmosph]e4 ,l>ge eng9es may use ! same air ov] & ov] aga9 "u pressure ( "o hundr$ p\nds p] squ>e in*1 alt]nately heat+ & cool+ x4 ,a six horse-p[] eng9e ( ?is type is said to h a cyl9d] f\r & "o-half in*es 9 diamet] & a /roke ( f\r & sev5-eigh? in*es1 & makes f\r hundr$ & fifty revolutions p] m9ute4 ,! heat] is tw5ty in*es 9 diamet]1 sixte5 in*es long1 & has a heat+ surface ( sixty squ>e feet4 ,! total weight ( heat] & eng9e complete is f\r hundr$ p\nds = a half horse-p[] ,ericsson eng9e4 ,! ,svea heat]1 says ,mr4 ,hesse1 absorbs ! heat z p]fectly z an ord9>y /eam boil]1 & ! heat-radiat+ surface ( bo? heat] & eng9e is n l>g] ?an t ( a /eam plant ( ! same p[]1 !reby plac+ ! two motors on ! same basis1 z f> z ! utilization ( ! heat 9 ! fuel itself is conc]n$4 ,! advantage :i* e hot-air eng9e has ov] ! /eam eng9e is ! am\nt ( heat sav$ 9 ! vaporization ( ! wat]4 ,x is n[ well kn[n t "o gas is z effici5t z ano!r = ! conv]sion ( heat into p[]4 ,air & /eam at #ajj ,c4 are consequ5tly on ! same foot+ & ready to be sup]heat$4 ,! am\nt ( heat requir$ to br+ ! two gases to ?is temp]ature is1 h[ev]1 v diff]5t4 ,) an initial temp]ature ( #aj ,c4 = bo? air & wat]1 we f9d t "o kilogram ( /eam requires #ij #ecg #fbg !rmal units1 & "o kilogram ( air #j4bd #ij #ba4f !rmal units4 ,"s heat is recov]$ if ! fe$ wat] is heat$ & ! /eam cond5s$1 b ! diff]5ce is /ill s great z to altoge!r exclude /eam z a competitor1 provid$ air c be z readily h&l$4 ,hav+ n[ ! means to rapidly heat ! air1 ! outlook = ! ext]nal-combu/ion eng9e is c]ta9ly v promis+4 ,! sav+ ( m ?an half ! coal n[ us$ by ! /eam eng9e w be ( trem5d\s importance to ! :ole _w4 ,to :at ext5t ?is optimi/ic pr$iction w be v]ifi$ is a problem = ! future to decide4 ,,viii ,,! ,,smalle/ ,,work]s ,9 our /udies ( ! /eam eng9e & gas eng9e we h be5 conc]n$ ) work]s ( inf9itesimal size4 ,yet1 if we are to believe ! reports ( ! mod]n inve/igator1 ! molecules ( /eam or ( ignit$ gas are small only 9 a relative s5se1 & !re is a legion ( work]s comp>$ ) :i* ! molecules are really gigantic 9 size4 ,^! work]s are ! atoms1 & ! yet m m9ute p>ticles ( :i*1 accord+ to ! mo/ rec5t !ories1 !y are !mselves compos$4 ,^! smalle/ conceivable p>ticles1 ! con/itu5ts ( ! atoms1 are call$ electrons4 ,!y are a discov]y ( ! physici/s ( ! mo/ rec5t g5]ation4 ,accord+ to ! newe/ !ories !y acc\nt = mo/--p]haps = all--( ! int]-molecul> & int]-atomic =ces2 !y are inde$ ! ultimate repositories ( ^? /ores ( en]gy :i* are kn[n to be conta9$ 9 all matt]4 ,! !ories are n q z fully develop$ z c\ld be wi%$1 b x w\ld appe> t ^! m9ute/ p>ticles1 ! electrons1 are ! ess5tial con/itu5ts ( ! famili> yet wond]ful c>ri] ( en]gy :i* we t]m electricity4 ,9 consid]+ ! %>e ( electricity 9 ! _w's "w1 !re=e1 we %all d well at ! outset to put ourselves 9 t\* ) rec5t views z to ! nature ( ?is mo/ rem>kable ( work]s4 ,on e side 9 ?is mod]n _w we are confront$ by ?is /range ag5t1 electricity4 ,! ^w />es u 9 ! face on e pr9t$ page4 ,! ?+ itself is manife/ 9 all dep>tm5ts ( our e-day life4 ,y g to y\r bus9ess 9 an electric c>2 asc5d to y\r (fice 9 an electric elevator2 utilize electric call-bells2 receive & transmit messages ab\t ! _w & b5ea? ! sea by electric telegraph4 ,y\r doctor treats y ) an electric batt]y4 ,y\r d5ti/ employs electric drills & electric furnaces4 ,y ride 9 electric cabs2 eat food cook$ on electric /oves2 & read ) ! aid ( electric light4 ,9 a ^w1 ! manife/ations ( electricity are s obvi\s on e side t !re c be no *all5ge to ! phras+ :i* has *ri/5$ ?is ! ,age ( ,electricity4 ,b :at1 !n1 is ?is /range p[] t has produc$ all ^! multif>i\s results8 ,x w\ld be h>d to prop\nd a sci5tific qu]y t has be5 m v>i\sly answ]$4 ,ev] s9ce ! fir/ primitive man obs]v$ ! /range effect produc$ by rubb+ a piece ( amb]1 ?\ghtful m9ds mu/ h /riv5 to expla9 t effect4 ,ev] s9ce ! eighte5?-c5tury sci5ti/ began 8 m elaborate /udies ( electricity1 !ories 9 abundance h be5 prop\nd$4 ,& yet we are n q sure t ev5 ! sci5ce ( to-day c give a correct answ] z to ! nature ( electricity4 ,at ! v lea/1 h[ev]1 x is able to give "s int]e/+ sugge/ions :i* seem to %[ t we are 9 a fair way to solve ?is _w-old my/]y4 ,&1 curi\sly en\gh1 ! v newe/ explanations are n s v f> away f "s eighte5?-c5tury !ories :i* = a long "t 7 look$ at askance if n altoge!r disc>d$4 ,9 p>ticul>1 ! !ory ( ,b5jam9 ,frankl91 :i* consid]$ electricity z an immat]ial fluid be>+ c]ta9 curi\s relations to tangible matt]1 is f\nd to s]ve s+ul>ly well z an aid to ! int]pretation ( ! v newe/ exp]im5ts4 ,,frankl9',s ,,"o-,,fluid ,,!ory ,su* be+ ! case1 we mu/ consid] ?is !ory ( ,frankl9's some:at 9 detail4 ,p]haps we _c d bett] ?an /ate ! !ory 9 ! words ( ! celebrat$ physici/1 ,dr4 ,?omas ,"y1 z giv5 9 8 "w on natural philosophy1 publi%$ 9 #ahjg4 ,by quot+ f ?is old "w we %all make sure t we are n read+ any mod]n int]pretations into ! !ory4 ,x is suppos$1 says ,"y1 t a peculi> e!real fluid p]vades ! pores1 if n ! actual sub/ance ( ! e>? & ( all o!r mat]ial bodies1 pass+ ?r\gh !m ) m or less facility1 accord+ to _! diff]5t p[]s ( conduct+ x2 t p>ticles ( ?is fluid repel ea* o!r1 & are attract$ by p>ticles ( common matt]2 t p>ticles ( common matt] also repel ea* o!r2 & t ^! attractions & repulsions are equal among !mselves1 & v>y inv]sely z to squ>es ( ! di/ances ( ! p>ticles4 ,! effects ( ?is fluid are di/+ui%$ f ^? ( all o!r sub/ances by an attractive or repulsive quality1 :i* x appe>s to communicate to diff]5t bodies1 & :i* diff]s 9 g5]al f o!r attractions & repulsions by its imm$iate dim9ution or cessation :5 ! bodies1 act+ on ea* o!r1 come into contact1 or are t\*$ by o!r bodies4444 ,9 g5]al1 a body is said to be electrifi$ :5 x conta9s1 ei!r z a :ole or 9 any ( its p>ts1 m or less ( ! electric fluid ?an is natural to x4444 ,9 ?is common neutral /ate ( all bodies1 ! electrical fluid1 :i* is ev]y:]e pres5t1 is s di/ribut$ t ! v>i\s =ces hold ea* o!r exactly 9 equilibrium & ! sep>ate results are de/roy$1 unless we *oose to consid] gravitation itself z aris+ f a comp>atively slight inequality betwe5 ! electrical attractions & repulsions4 ,! sali5t & /rik+ feature ( ?is !ory1 x w be obs]v$1 is t ! electrical fluid1 "u normal conditions1 is suppos$ to be incorporat$ ev]y:]e ) ! sub/ance ( e mat]ial 9 ! _w4 ,x w be obs]v$ t no?+ :atev] is po/ulat$ z to ! nature or prop]ties ( ?is fluid beyond ! fact t its p>ticles repel ea* o!r & are attract$ by ! p>ticles ( common matt]2 x be+ also po/ulat$ t ! p>ticles ( common matt] likewise repel ea* o!r "u normal conditions4 ,at ! "t :5 ,frankl9 prop\nd$ 8 !ory1 !re 0 a rival !ory be=e ! _w1 :i* has cont9u$ m or less popul> ev] s9ce1 & :i* is kn[n z ! two-fluid !ory ( electricity4 ,accord+ to ?is !ory1 !re are two uncreat$ & inde/ructible fluids :i* produce electrical effects4 ,"o fluid may be call$ positive1 ! o!r negative4 ,! p>ticles ( ! positive fluid are mutually repell5t1 z also are ! p>ticles ( ! negative fluid1 b1 on ! o!r h&1 positive p>ticles attract & are attract$ by negative p>ticles4 ,we ne$ n fur!r elaborate ! details ( ?is two-fluid !ory1 because ! be/ mod]n op9ion consid]s x less satisfactory ?an ,frankl9's "o-fluid !ory4 ,meantime1 x w be obs]v$ t ! two !ories h mu* 9 common2 9 p>ticul> !y agree 9 ! ess5tial feature ( po/ulat+ an invisible some?+ :i* is n matt]1 & :i* has /range prop]ties ( attraction & repulsion4 ,^! prop]ties ( attraction & repulsion con/itut$ 9 ! e>ly day ! only kn[n manife/ations ( electricity2 & ! same prop]ties cont9ue to hold an important place 9 mod]n /udies ( ! subject4 ,electricity is s nam$ simply because amb]--! ,lat9 electrum--0 ! sub/ance :i*1 9 ! exp]i5ce ( ! anci5ts1 %[$ mo/ conspicu\sly ! /range prop]ty ( attract+ small bodies aft] be+ rubb$4 ,mod]n me?ods ( develop+ electricity are extremely div]sifi$1 & mo/ ( !m are q unsugge/ive ( ! rubb+ ( amb]2 yet ne>ly all ! v>i$ manife/ations ( electricity are r$ucible1 9 ! la/ analysis1 to attractions & repulsions among ! p>ticles ( matt]4 ,z to ! alleg$ immat]ial fluids :i*1 accord+ to ! !ories j m5tion$1 make up ! real sub/ance ( electricity1 x 0 p]fectly natural t !y %\ld be inv5t$ by ! physici/s ( ! eld] day4 ,all ! conceptions ( ! human m9d are develop$ ?r\gh contact ) ! mat]ial _w2 & x is extremely difficult to get away1 ev5 9 !ory1 f tangible realities4 ,:5 ! rubb$ amb] acquires ! prop]ty ( draw+ ! pi? ball to x1 we naturally assume t "s *ange has tak5 place 9 ! condition ( ! amb]2 & s9ce ! visible p>ticles ( amb] appe> to be un*ang$--s9ce its color1 weight1 & friability are unmodifi$--x seems z if "s immat]ial quality mu/ h be5 add$ to1 or tak5 f x4 ,& x 0 natural = ! eighte5?-c5tury physici/ to ?9k ( ?is immat]ial some?+ z a fluid1 because he 0 accu/om$ to ?9k ( light1 heat1 & magnetism z be+ also immat]ial fluids4 ,he did n "k1 z we n[ d1 t :at we call heat is m]ely ! manife/ation ( v>y+ modes ( motion among ! p>ticles ( matt]1 & t :at we call light is n a ?+ sui g5]is1 b is m]ely our recognition ( waves ( c]ta9 l5g? 9 ! all-p]vad+ e!r4 ,! wave !ory ( light _h1 inde$1 be5 prop\nd$ "h & !re by a philosoph]1 b ! !ory :i* reg>d$ light z a corpuscul> emanation _h ! support ( no less an au?ority ?an ,sir ,isaac ,newton1 & he 0 a bold !ori/ t d>$ *all5ge x4 ,:5 ,frankl9 prop\nd$ 8 !ory ( electricity1 !re=e1 8 assumption ( ! immat]ial fluid 0 ?or\ghly 9 accord ) ! physical doctr9es ( ! "t4 ,,mod]n ,,views ,b ab\t ! beg9n+ ( ! n9ete5? c5tury ! doctr9e ( impond]able fluids z appli$ to light & heat 0 actively *all5g$ by ,"y & ,fresnel & by ,c\nt ,rum=d & ,humphry ,davy & _! foll[]s1 & 9 due c\rse ! new doctr9es ( light & heat 7 ?or\ghly e/abli%$4 ,9 ! light ( ! new k1 ! !ory ( ! electric fluid or fluids seem$1 !re=e1 mu* less plausible4 ,:]eas ! e>li] physici/s _h m]ely disput$ z to :e!r we mu/ assume ! exi/5ce ( two electrical fluids or ( only "o1 x n[ began to be que/ion$ :e!r we ne$ assume ! exi/5ce ( any electrical fluid :atev]4 ,! physici/s ( ab\t ! middle ( ! n9ete5? c5tury develop$ ! wond]ful doctr9e ( cons]vation ( en]gy1 accord+ to :i* "o =m ( =ce may be trans=m$ into ano!r1 b )\t ! possibility ( add+ to1 or subtract+ f1 ! orig9al sum total ( en]gy 9 ! univ]se4 ,x became evid5t t electrical =ce mu/ con=m to ?is law4 ,f9ally1 ,cl]k-,maxwell develop$ 8 wond]ful electromagnetic !ory1 accord+ to :i* waves ( light are ( electrical orig94 ,! "w ( ,maxwell 0 foll[$ up by ! ,g]man ,h]tz1 ^: exp]im5ts produc$ ^? electromagnetic waves :i*1 diff]+ 9 no respect except 9 _! l5g? f ! waves ( light1 h become famili> to ev]yone ?r\gh _! use 9 wireless telegraphy4 ,all ^! exp]im5ts %[$ a close relation betwe5 electrical ph5om5a1 & ! ph5om5a ( light & ( radiant heat1 & a long /ep seem$ to be tak5 t[>d ! explanation ( ! nature ( electricity4 ,! new /udies associat$ electricity ) ! e!r1 r ?an ) ! mat]ial sub/ance ( ! electrifi$ body4 ,_m exp]im5ts seem$ to %[ t electricity 9 motion trav]ses *iefly ! surface ( ! conductor1 & x came to be believ$ t ! ess5tial feature ( ! curr5t consi/s ( a condition ( /ra9 or /ress 9 ! e!r surr\nd+ a conductor1 r ?an ( any *ange 9 ! conductor itself4 ,?is idea1 :i* is /ill consid]$ valid1 has ! m]it ( do+ away ) ! ?\ght ( action at a di/ance--! idea t 0 s repugnant to ! m9d ( ,f>aday4 ,s f> s good4 ,b :at det]m9es ! e!r /ra98 ,!re is surely some?+ t is n matt] & is n e!r4 ,:at is ?is some?+8 ,! ef=ts ( _m ( ! mo/ di/+ui%$ exp]im5t]s h 9 rec5t ye>s be5 direct$ t[>d ! solution ( t "q2 & ^! ef=ts1 ?anks to ! new me?ods & new discov]ies1 h met ) a consid]able measure ( success4 ,i mu/ n attempt "h to foll[ out ! *annels ( discov]y1 b mu/ cont5t myself ) /at+ briefly ! results4 ,we %all h occasion to consid] "s fur!r details z to ! me?ods 9 a lat] *apt]4 ,briefly1 !n1 x is n[ g5]ally accept$1 at lea/ z a work+ hypo!sis1 t e atom ( matt]--be x oxyg51 hydrog51 gold1 iron1 or :at n--c>ries a *>ge ( electricity1 :i* is probably responsible = all ! ph5om5a t ! atom manife/s4 ,?is *>ge ( electricity may be positive or negative1 or x may be neutral1 by :i* is meant t ! positive & negative *>ges may j balance4 ,if ! positive *>ge has def9ite c>ri]s1 ^! are unkn[n except 9 association ) ! atom itself2 b ! negative *>ge1 on ! o!r h&1 is c>ri$ by m9ute p>ticles to :i* ! "n electron 7or corpuscle7 has be5 giv51 ea* ( :i* is ab\t "o ?\s& times small] ?an a hydrog5 atom1 & ea* ( :i* c>ries uni=mly a unit *>ge ( negative electricity4 ,electrons are comb9$1 9 :at may be call$ planet>y sy/ems1 9 ! sub/ance ( ! atom2 inde$1 x is n c]ta9 t ! atom consi/s ( any?+ else b su* comb9ations ( electrons1 held toge!r by ! inscrutable =ce ( positive electricity4 ,"s1 at lea/1 ( ! electrons )9 ! atom are viol5tly active--p]haps :irl+ 9 planet>y orbits1--& f "t to "t "o or m electrons may escape f ! atomic sy/em4 ,9 ?us escap+ an electron takes away its *>ge ( negative electricity1 & ! previ\sly neutral atom becomes positively electrifi$4 ,mean:ile ! free electron may hurtle ab\t ) its *>ge ( negative electricity1 or may comb9e ) "s neutral atom & ?us give to t neutral atom a negative *>ge4 ,"u c]ta9 conditions myriads ( ^! electrons1 escap$ ?us f _! atomic sy/ems1 may exi/ 9 ! free /ate4 ,= example1 ! s-call$ beta 77 rays ( radium & its allies consi/ ( su* electrons1 :i* are be+ hurtl$ (f into space ) approximately ! spe$ ( light4 ,! ca?ode rays1 ( :i* we h he>d s mu* 9 rec5t ye>s1 also consi/ ( free electrons4 ,b1 = t matt]1 all curr5ts ( electricity :atev]1 accord+ to ?is newe/ !ory1 consi/ simply ( aggregations ( free electrons4 ,accord+ to !ory1 if ! electrons are 9 uni=m motion !y produce ! ph5om5a ( con/ant curr5ts ( electricity2 if !y move non-uni=mly !y produce electromagnetic ph5om5a 7= example1 ! waves us$ 9 wireless telegraphy72 if !y move ) p]iodic motion !y produce ! waves ( light4 ,mean:ile /ation>y aggregations ( electrons produce ! s-call$ electro/atic ph5om5a4 ,all ! v>i\s e!r waves are ?us believ$ to be produc$ by *anges 9 ! motions ( ! electrons4 ,a v sudd5 /oppage1 su* z is produc$ :5 ! ca?ode ray meets an impassable b>ri]1 produces ! ,x-ray4 ,) ^! explanations 9 m9d1 x w be obvi\s h[ closely ?is newe/ int]pretation ( electricity corresponds 9 its g5]al features ) ! old "o-fluid !ory ( ,frankl94 ,! ef=ts ( ! pres5t-day physici/ h result$ ess5tially 9 an analysis ( ,frankl9's fluid1 :i* gives to ?is fluid an atomic /ructure4 ,! new !ory takes a /ep beyond ! old 9 sugge/+ ! idea t ! same p>ticles :i* make up ! electric fluid ent] also into ! composition--p]haps are ! sole physical con/itu5ts--( e mat]ial sub/ance z well4 ,b :ile ! new !ory ?us ext5ds ! b\nds ( our vision1 we mu/ n claim t x fully solves ! my/]y4 ,we c visualize ! ultimate con/itu5t ( electricity z an electron "o ?\s& times small] ?an ! hydrog5 atom1 :i* has mass & in]tia1 & :i* possesses p[]s ( attraction & repulsion4 ,b z to ! actual nature ( ?is ultimate p>ticle we are /ill 9 ! d>k4 ,!re are1 h[ev]1 "s int]e/+ !ories z to its "*1 :i* %\ld claim at lea/ incid5tal att5tion4 ,we h all along spok5 ( ! electron z an exce$+ly m9ute p>ticle1 /at+ inde$1 t 9 actual size x is believ$ to be ab\t "o ?\s& times small] ?an ! hydrog5 atom1 :i* hi!rto _h be5 consid]$ ! smalle/ ?+ kn[n to sci5ce4 ,b we h n[ to (f] a seem+ly p>adoxical modification ( ?is /atem5t4 ,x is true t 9 mass or weight ! electron is a ?\s& times small] ?an ! hydrog5 atom1 yet at ! same "t x may be conceiv$ t ! limits ( space :i* ! electron occupies are indef9itely l>ge4 ,9 a ^w1 x is conceiv$ 7by ,pr(essor ,j4 ,j4 ,?omson1 :o is ! *ief pa?-break] 9 ?is field7 t ! electron is 9 reality a sort ( inf9itesimal magnet1 hav+ two poles jo9$ by l9es or tubes ( magnetic =ce 7! s-call$ ,f>aday tube71 :i* l9es or tubes are ( indef9ite numb] & ext5t2 precisely z1 on a l>ge scale1 our t]re/rial globe is su* a magnet suppli$ ) su* an indef9ite magnetic field4 ,t ! mass ( ! electron is s inf9itesimally small is expla9$ on ! assumption t ?is mass is due to a c]ta9 am\nt ( univ]sal e!r :i* is b\nd up ) ! tubes :]e !y are ?icke/2 close to ! po9t 9 space f :i* !y radiate1 :i* po9t 9 space con/itutes ! focus ( ! tangible electron4 ,x w require "s close ?9k+ on ! "p ( ! read] to ga9 a cle> m5tal picture ( ?is conception ( ! electron2 b ! result is wor? ! ef=t4 ,:5 y c cle>ly conceive all matt] z compos$ ( electrons1 ea* "o ( :i* cobwebs space ) its sy/em ( magnetic tubes1 y w at lea/ h a tangible picture 9 m9d ( a possible explanation ( ! =ces ( cohesion & gravitation--9 fact1 ( all ! obs]v$ cases ( seem+ action at a di/ance4 ,if at fir/ blu% ! conception ( space z fill$ ) an int]m9able me%work ( l9es ( =ce seems to involve u 9 a hopeless m5tal tangle1 x %\ld be recall$ t ! exi/5ce ( an inf9ity ( su* magnetic l9es jo9+ ! poles ( ! e>? may be demon/rat$ at any "t by ! obs]vation ( a compass1 yet t ^! d n 9 any way int]f]e ) ! play ( o!r famili> =ces4 ,!re is no?+ un?9kable1 !n1 9 ! supposition t !re are myriads ( m9or magnetic c5tres ex]t+ less] degrees ( =ce ?r\gh\t ! same space4 ,all t c be sugge/$ z to ! actual nature ( ! ,f>aday tubes is t !y p]haps repres5t a condition ( ! e!r4 ,?is1 obvi\sly1 is heap+ hypo!sis ^u hypo!sis4 ,yet x %\ld be und]/ood t ! hypo!sis ( ! magnetic electron z ! basis ( matt]1 has receiv$ an am\nt ( exp]im5tal support t has rais$ x at lea/ to ! level ( a work+ !ory4 ,%\ld t !ory be demon/rat$ to be true1 we %all app>5tly be =c$ to conclude n m]ely t electricity is pres5t ev]y:]e 9 nature1 b t1 9 ! la/ analysis1 !re is absolutely no tangible ?+ o!r ?an electricity 9 all ! univ]se4 ,,h[ ,,electricity ,,is ,,develop$ ,turn+ f ?is v />tl+ !oretical conclusion to ! practicalities1 let u inquire h[ electricity--:i* app>5tly exi/s1 z x 71 9 embryo ev]y:]e--c be made manife/4 ,9 s do+ we %all discov] t !re are v>y+ types ( electricity1 yet t ^! h a s+ul> uni=mity z to _! ess5tial prop]ties4 ,z usually divid$--& ! classification answ]s p>ticul>ly well f ! /&po9t ( ! work]--electricity is spok5 ( z ei!r /atical or dynamical4 ,! words !mselves are sugge/ive ( ! ess5tial diff]5ce betwe5 ! two types4 ,/atical electricity produces v /rik+ manife/ations4 ,we h already spok5 ( x z !oretically due to ! conditions ( ! electrons at re/4 ,x mu/ be und]/ood1 h[ev]1 t ! /atical electricity w1 if giv5 opportunity1 seek to escape f any giv5 location to ano!r location1 "u c]ta9 conditions1 some:at z wat] :i* is /or$ up 9 a res]voir w1 :5 opportunity (f]s1 fl[ d[n to a l[] level4 ,! p5t-up /atic electricity has1 l ! wat] 9 ! res]voir1 a /ore ( pot5tial en]gy4 ,! physici/ speaks ( x z hav+ high t5sion4 ,9 pass+ to a condition ( l[] t5sion1 ! /atical electricity may give up a l>ge portion ( its en]gy4 ,if1 = example1 on a w9t] day 9 a cold climate1 y walk briskly along a wool c>pet1 ! friction ( y\r feet ) ! c>pet g5]ates a /ore ( /atical electricity1 :i* imm$iately passes ov] ! entire surface ( y\r body4 ,if n[ y t\* ano!r p]son or a metal conductor1 su* z a /eam radiator or a gas pipe1 a brilliant sp>k jumps f y\r f+]1 & y exp]i5ce :at is spok5 ( z an electrical %ock4 ,if ! day is v cold1 & ! air consequ5tly v dry1 & if y w take pa9s to rub y\r feet vigor\sly or slide along ! c>pet1 y may light a gas jet ) ! sp>k :i* w spr+ f y\r f+] to ! tip ( ! jet1 provid$ ! latt] is ( metal or o!r conduct+ sub/ance2 & ev5 if y attempt to avoid ! friction betwe5 y\r feet & ! c>pet z mu* z possible1 y may be con/antly annoy$ by receiv+ a %ock :5ev] y t\* any conductor1 s9ce1 9 spite ( y\r ef=ts1 ! necess>y am\nt ( friction suffic$ to g5]ate a /ore ( /atical electricity4 ,an illu/ration ( ! developm5t ( ?is same =m ( electricity1 on a l>ge scale1 is suppli$ by ! famili> /atical ma*9e1 :i* consi/s ( a l>ge circle ( glass1 s adju/$ t x may be revolv$ rapidly aga9/ a suitable friction produc]4 ,) su* a ma*9e a p[]ful /atical curr5t is produc$1 capable ( g5]at+ a sp>k t may be _m in*es or ev5 sev]al feet 9 l5g?1--a v]itable fla% ( lightn+4 ,x is ) su* a supply ( electricity conduct$ ?r\gh a vacuum tube t ! ca?ode ray & ! ,ro5tg5 ray are produc$4 ,su* effects z ?is sugge/ consid]able capacity = do+ "w4 ,yet 9 reality1 not)/&+ ! v sporadical "* ( ! result1 ! quantity ( electricity involv$ 9 su* a /atical curr5t may be v slight inde$4 ,ev5 a lightn+ fla% is held to repres5t a comp>atively small am\nt ( electricity4 ,f>aday calculat$ t ! am\nt ( electricity t c\ld be g5]at$ f a s+le drop ( wat]1 ?r\gh *emical manipulation1 w\ld suffice to supply ! lightn+ = a fair-siz$ ?und]-/orm4 ,nev]!less ! de/ructive "w t may be done by a fla% ( lightn+ may be consid]able1 z ev]yone is aw>e4 ,b1 on ! o!r h&1 :ile ! visible effect ( a /roke ( lightn+ on a tree trunk1 = example1 makes x seem a p[]ful ag5cy1 yet ! actual capacity to d "w--! p[] to move consid]able masses ( matt]--is extremely limit$4 ,! effect on a tree trunk1 x w be recall$1 usually consi/s ( no?+ m ?an ! /ripp+ (f ( a *annel ( b>k4 ,9 o!r words1 ! work+ en]gy conta9$ 9 a seem+ly p[]ful supply ( /atical electricity commonly plays b an insignificant "p4 ,! work+ ag5t1 & !re=e ! =m ( electricity :i* conc]ns u 9 ! pres5t connection1 is ! dynamical curr5t4 ,?is may be g5]at$ 9 v>i\s ways1 b 9 practice ^! are *iefly r$ucible to two4 ,"o ( ^! dep5ds ^u *emical action1 ! o!r ^u ! int]-relations ( me*anical motion & magnetic l9es ( =ce4 ,a common illu/ration ( ! =m] is suppli$ by ! famili> voltaic or galvanic batt]y4 ,! electromagnetic =m has be5 r5d]$ ev5 m famili> 9 rec5t times by ! dynamo4 ,?is newe/ & mo/ p[]ful ( work]s w claim our att5tion 9 detail 9 ! succe$+ *apt]4 ,our pres5t consid]ation w be direct$ to ! old] me?od ( g5]at+ ! electric curr5t z repres5t$ by ! voltaic cell4 ,,! ,,"w ,,( ,,! ,,dynamical ,,curr5t ,let u draw our illu/ration f a famili> s\rce4 ,ev5 %\ld y\r h\sehold o!rwise lack electrical appliances1 y are sure to h an electric call-bell4 ,! g5]ator ( ! electric curr5t1 :i* is /or$ away 9 "s out-(-!-way corn]1 is probably a small s-call$ dry-cell :i* y c\ld readily c>ry ar\nd 9 y\r pocket2 or x may consi/ ( a receptacle hold+ a p9t or two ( liquid 9 :i* "s metal plates are imm]s$4 ,su* an app>atus seems sc>cely m ?an a toy :5 we contra/ x ) ! gigantic dynamos ( ! p[]-h\se2 yet1 )9 ! limits ( its capacities1 "o is z surely a g5]ator ( electricity z ! o!r4 ,if we are to accept ! late/ !ory1 ! electrical curr5t :i* fl[s f ?is t9y cell is precisely ! same 9 k9d z t :i* fl[s f ! five-?\s&-horse-p[] dynamo4 ,! diff]5ce is only "o ( quantity4 ,to und]/& ! op]ation ( ?is common h\sehold appliance we mu/ be> 9 m9d two or ?ree famili> exp]im5tal facts 9 ref]5ce to ! action ( ! voltaic cell4 ,briefly1 su* a cell consi/s ( two plates ( metal--= example1 "o ( copp] & ! o!r ( z9c--) a connect+ m$ium1 :i* is usually a liquid1 b :i* may be a piece ( moi/5$ clo? or blott+-pap]4 ,s long z ! two plates ( metal are n o!rwise connect$ !re is no electricity 9 evid5ce1 b :5 ! two are jo9$ by any metal conductor1 z1 = example1 a piece ( wire--?us1 9 common p>lance1 complet+ ! circuit--a curr5t ( electricity fl[s ab\t ?is circuit1 pass+ f ! fir/ metal plate to ! second1 ?r\gh ! liquid & back f ! second plate to ! fir/ ?r\gh ! piece ( wire4 ,! wire may be ( any l5g?4 ,9 ! case ( y\r call-bell1 = example1 ! wire circuit ext5ds to y\r door1 & is !re brok51 %utt+ (f ! curr5t4 ,:5 y press ! button y connect ! brok5 ends ( ! wire1 ?us clos+ ! circuit1 z ! say+ is1 & ! re-e/abli%$ curr5t1 act+ ?r\gh a little electromagnet1 r+s ! bell4 ,9 ano!r case1 ! wire may be hundr$s ( miles 9 l5g?1 to s]ve ! purposes ( ! telegraph]1 :o transmits 8 message by op5+ & clos+ ! circuit1 precisely z y op]ate y\r door-bell4 ,= long-di/ance telegraphy1 ( c\rse1 l>ge cells are requir$1 & numb]s ( !m are l9k$ toge!r to give a cumulative effect1 mak+ a /rong curr5t2 b !re is no new pr9ciple involv$4 ,! simple/ /udy ( ?is int]e/+ me*anism makes x cle> t ! cell is ! app>atus prim>ily involv$ 9 g5]at+ ! electric curr5t2 yet x is equally obvi\s t ! connect+ wire plays an important "p1 s9ce1 z we h se51 :5 ! wire is brok5 !re is no curr5t 9 evid5ce4 ,n[1 accord+ to ! electron !ory1 z previ\sly outl9$1 ! electric curr5t consi/s ( an actual fl[ along ! wire ( c>ri]s ( electricity :i* are unable to make _! way except :]e a c\rse is provid$ = !m by :at is call$ a conductor4 ,dry air1 = example1 is1 "u ord9>y circum/ances1 q imp]vi\s to !m4 ,?is means1 !n1 t ! electrons fl[ freely along ! wire :5 x is cont9u\s1 b t !y are p[]less to proce$ :5 ! wire is cut4 ,:5 y pu% ! button ( y\r call-bell1 !re=e1 y are virtually clos+ ! swit* :i* enables ! electrons to proce$ on _! int]rupt$ j\rney4 ,,!ories ,,( ,,electrical ,,action ,b all ?is1 ( c\rse1 leaves q unt\*$ ! "q ( ! orig9 ( ! electrons !mselves4 ,t ^! g hurtl+ f "o plate or pole ( ! batt]y to ! o!r1 along ! wire1 we c und]/& at lea/ z a work+ !ory2 t1 fur!rmore1 ! electrons h _! orig9 ei!r 9 ! metal plates or 9 ! liquid t connects !m1 seems equally obvi\s2 b h[ %all we acc\nt = _! developm5t8 ,x is "h t ! *emi/ ) 8 atomic !ory ( matt] comes to our aid4 ,he assures u t all matt] consi/s 9 ! la/ analysis ( excessively m9ute p>ticles1 & t ^! p>ticles are p]petually 9 motion4 ,!y unite ) "o ano!r to =m s-call$ molecules1 b !y are p]petually break+ away f su* unions1 ev5 ?\gh !y re-e/abli% !m aga94 ,su* activities ( ! atoms take place ev5 9 solids1 b !y are greatly enhanc$ :5 any sub/ance passes f ! solid into ! liquid /ate4 ,:51 = example1 a lump ( salt is dissolv$ 9 wat]1 ! atoms ( sodium & ( *lor9e :i* jo9$ toge!r make up ! molecules ( salt are held 9 mu* loos] bondage ?an !y 7 :ile ! salt 0 9 a dry or cry/all9e =m4 ,c\ld we magnify ! inf9itesimal p>ticles suffici5tly to make !m visible we %\ld probably see l>ge numb]s ( ! molecules be+ dissociat$1 ! lib]at$ atoms mov+ ab\t freely = an in/ant & !n reunit+ ) o!r atoms4 ,?us at any giv5 in/ant our solution ( salt w\ld conta9 num]\s free atoms ( sodium & ( *lor9e1 al?\gh we are ju/ifi$ 9 ?9k+ ( ?is sub/ance z a :ole z compos$ ( sodium-*lor9e molecules4 ,x is only by ?us visualiz+ ! activity ( ! atoms 9 a solution t we are able to provide ev5 a ?9kable hypo!sis z to ! developm5t ( electricity 9 ! voltaic cell4 ,:at puts u on ! track ( ! explanation we are seek+ is ! fact t ! div]se atoms are kn[n to h diff]5t electrical prop]ties4 ,9 our voltaic cell1 = example1 sodium atoms w\ld collect at "o pole & *lor9e atoms at ! o!r4 ,humphry ,davy discov]$ ?is fact 9 ! e>ly days ( electro-*emi/ry1 j ab\t a c5tury ago4 ,he spoke ( ! sodium atom z electro-positive1 & ( ! *lor9e atom z electro-negative1 & he attempt$ to expla9 all *emical aff9ity z m]ely due to ! mutual attraction betwe5 positively & negatively electrifi$ atoms4 ,! mod]n !ori/ goes "o /ep f>!r1 & expla9s ! negative prop]ties ( ! *lor9e atom by assum+ ! pres5ce ( "o negative electron or electricity 9 excess ( ! neutraliz+ *>ge4 ,! assumption is1 t ! sodium atom has lo/ ?is negative electron & ?us has become positively electrifi$4 ,! *lor9e atom1 h>bor+ ! fugitive electron1 becomes negatively electrifi$4 ,h5ce ! two atoms are attract$ t[>d opposite poles ( ! cell4 ,?is disunion ( atoms1 be x und]/ood1 mu/ be suppos$ to take place 9 ! case ( any solution ( common salt1 :e!r x re/s 9 an ord9>y cup or =ms a "p ( ! ocean4 ,"h we h1 !n1 mat]ial = ! g5]ation ( ! electrical curr5t1 if "s means c\ld be f\nd to induce ! *lor9e atom to give up ! surplus electron :i* f "t to "t x c>ries4 ,& ?is means is provid$ :5 two pieces ( metal ( diff]5t k9ds1 unit$ ) a metal conductor1 are imm]s$ 9 ! liquid4 ,!n x comes to pass t ! electrons associat$ ) ! *lor9e atoms t *ance to lie 9 contact ) "o ( ^! plates ( metal1 f9d 9 ?is metal an av5ue ( escape4 ,!y ru% (f eag]ly along ! metal & ! connect+ wire1 & 9 s do+ e/abli% a curr5t :i* acts--if we may v5ture a graphic analogy f an alli$ field ( physics--z a sort ( suction1 attract+ o!r *lor9e atoms f ! body ( ! liquid aga9/ ! metal plate t !y also may dis*>ge _! electrons4 ,9 o!r words1 ! electrical curr5t passes ?r\gh ! liquid z well z ?r\gh ! outside wire1 ?us complet+ ! circuit4 ,accord+ to ?is !ory1 !n1 ! electrical en]gy 9 evid5ce 9 ! curr5t f ! voltaic cell1 is drawn f a /ore ( pot5tial en]gy 9 ! atoms ( matt] compos+ ! liquid 9 ! cell4 ,9 practice1 z is well kn[n1 ! liquid us$ is "o t affects "o ( ! metal poles m actively ?an ! o!r1 insur+ vigor\s *emical activity4 ,b ! pr9ciple ( atomic & electrical dissociation j outl9$ is ! "o involv$1 accord+ to !ory1 9 e voltaic cell1 :atev] ! p>ticul> comb9ation ( metals & liquids ( :i* x is compos$4 ,x %\ld be add$1 h[ev]1 t :ile we are ?us suppli$ ) a ?9kable explanation ( ! orig9 ( ?is manife/ation ( electrical en]gy1 no explanation is =?com+1 "h any m ?an 9 ! case ( ! dynamo1 z to :y ! electrons ru% (f 9 a p>ticul> direction & ?us e/abli% an electrical curr5t4 ,p]haps we %\ld recall t ! v exi/5ce ( ?is curr5t has at times be5 d\bt$4 ,q rec5tly1 inde$1 x has be5 held t ! seem+ curr5t consi/s m]ely ( a condition ( /ra9 or displacem5t ( ! e!r4 ,b we are "h *iefly conc]n$ ) ! electron !ory1 accord+ to :i*1 z we h all along not$1 ! seem+ curr5t is an actual curr5t2 ! e!r /ra91 if su* exi/s1 be+ due to ! passage ( ! electrons4 ,,practical ,,uses ,,( ,,electricity ,v>i\s effects ( ! curr5t ( electrons h be5 h9t$ at above4 ,consid]$ 9 detail1 ! possible ways 9 :i* ^! curr5ts may be utiliz$ are multif>i\s4 ,yet1 !y may be all r\ghly classifi$ into ?ree divisions z foll[s3 ,fir/1 cases 9 :i* ! curr5t ( electricity is us$ to transmit en]gy f "o place to ano!r1 & reproduce x 9 ! =m ( mol> motion4 ,! dynamo1 9 its endless applications1 illu/rates "o phase ( su* transportation ( en]gy2 & ! call-bell1 ! telegraph1 & ! telephone repres5t ano!r phase4 ,9 "o case a relatively l>ge quantity ( electricity is necess>y1 9 ! o!r case a small quantity2 b ! pr9ciple involv$--t ( electric & magnetic induction--is ! same 9 ea*4 ,! second me?od is t 9 :i* ! curr5t1 g5]at$ by ei!r a dynamo or a batt]y ( voltaic cells1 is made to enc\nt] a relatively resi/ant m$ium 9 ! c\rse ( its fl[ along ! conduct+ circuit4 ,su* resi/ance leads to ! production ( active vibrations among ! p>ticles ( ! resi/+ m$ium1 produc+ ! ph5om5a ( heat &1 if ! activity is suffici5t1 ! ph5om5a ( light also4 ,x w ?us appe> t 9 ?is class ( cases1 z 9 ! o!r1 !re is an actual re-trans=mation ( electrical en]gy into ! en]gy ( motion1 only 9 ?is case ! motion is t ( molecules & n ( l>g] bodies4 ,! pr9ciple is utiliz$ 9 ! electrical heat]1 ) :i* our electric /reet-c>s are commonly provid$1 & :i* is mak+ its way 9 ! h\sehold = purposes ( g5]al heat+ & ( cook+4 ,x is utiliz$ also 9 v>i\s factories1 :]e ! v high degree ( heat atta9able ) ! electrical furnace is employ$ to produce *emical dissociation & facilitate *emical comb9ations4 ,by ?is means1 = example1 a comp\nd ( c>bon & silicon1 :i* is said to be ! h>de/ kn[n sub/ance1 except ! diamond1 is produc$ 9 comm]cial quantities4 ,a famili> h\sehold illu/ration ( ! use ( ?is pr9ciple is furni%$ by ! electric light4 ,! c>bon filam5t 9 ! electric bulb furni%es su* resi/ance to ! electric curr5t t its p>ticles are set viol5tly aquiv]4 ,"u ord9>y conditions ! oxyg5 ( ! air w\ld imm$iately unite ) ! c>bon p>ticles1 volatiliz+ !m1 & ?us in/antly de/roy+ ! filam5t2 b ! vacuum bulb excludes ! air1 & ?us gives relative p]man5cy to ! fragile ?read4 ,! ?ird class ( cases 9 :i* ! electric curr5t is comm]cially utiliz$ is t 9 :i* ! trans=mations x effects are produc$ 9 solutions comp>able to ^? ( ! voltaic cell1 ! pr9ciples involv$ be+ ^? po9t$ out 9 ! e>li] "p ( ! pres5t *apt]4 ,by ?is means a metal may be deposit$ 9 a pure /ate ^u ! surface ( ano!r metal made to act z a pole to ! batt]y2 z1 = example1 :5 =ks1 spoons1 & o!r ut5sils ( *eap metals are plac$ 9 a solution ( a silv] comp\nd1 & ?us electroplat$ ) silv]4 ,to produce ! p[]ful effects necess>y 9 ! v>i\s comm]cial applications ( ?is pr9ciple1 ! poles ( ! voltaic cell--:i* cell may become 9 practice a l>ge tank--are connect$ ) ! curr5t suppli$ by a dynamo4 ,v>i\s *emical plants at ,niag>a utilize portions ( ! curr5ts f ! great g5]ators !re 9 ?is way4 ,ano!r famili> illu/ration ( ! pr9ciple is furni%$ by ! copp] electroplates f :i* mo/ mod]n books are pr9t$4 ,x appe>s1 !n1 t all ! multif>i\s uses ( electricity 9 mod]n life are r$ucible to a few simple pr9ciples ( action1 j z electricity itself is r$uc$1 accord+ to ! analysis ( ! mod]n physici/1 to ! activities ( ! elem5t>y electron4 ,!re is no?+ anomal\s 9 ?is1 h[ev]1 = 9 ! la/ analysis ! me*anical pr9ciples involv$ 9 do+ all ! _w's "w are few & relatively simple1 h[ev] +5i\s & relatively complex may be ! appliances ?r\gh :i* ^! pr9ciples are made available4 ,,ix ,,man',s ,,newe/ ,,co-,,labor]3 ,,! ,,dynamo ,z y /& wait+ = y\r tra9 at elevat$ or subway /ation y mu/ h notic$ ! ?ird rail4 ,to outw>d appe>ance x is n diff]5t f ! o!r rails4 ,x seems a m]e in]t piece ( /eel4 ,yet y are well aw>e t a /range p[] abides !re unse5--a p[] t pulls ! tra91 & t lurks 9 hid+ to /rike a dea?-bl[ to any *ance un=tunate ^: foot or h& comes 9 contact ) ! rail4 ,z ! heavy tra9 da%es up1 dragg$ by ?is unse5 p[]1 probably y1 9 common ) ! re/ ( ! _w1 h be5 l$ to rem>k1 ,is x n m>vel\s8 ,m>vel\s x surely seems4 ,yet ! cause ( our a/oni%m5t is to be s\ght 9 ! relative newness ( ! ph5om5a r ?an 9 ! nature ( ! ph5om5a !mselves4 ,at fir/ glance x may seem t ! intangible "* ( ! electrical p[] gives x a unique claim on our wond]m5t4 ,b a mom5t's reflection dispels ?is illusion4 ,aft] all1 electricity is no m intangible ?an heat4 ,nei!r ! "o nor ! o!r c be se5 or he>d1 b ea* alike may be felt4 ,yet we obs]ve )\t a/oni%m5t a locomotive propell$ by ! p[] ( heat--simply because ! locomotive has become an old /ory4 ,aga91 electricity is f> less intangible ?an gravitation4 ,n m]ely may electricity be felt1 b x may be g5]at$ ?r\gh trans=mation ( o!r =ms ( en]gy2 x may be /or$ away & measur$2 may be conduct$ at w ?r\gh tortu\s *annels1 or ob/ruct$ 9 its flight by ! int]v5tion ( non-conductors4 ,b gravitation submits to no su* re/rictions4 ,x eludes all ( our s5ses1 & x absolutely disreg>ds all b>ri]s4 ,to its ca?olic ta/e all sub/ances are alike4 ,x holds 9 bondage e p>ticle ( matt] 9 ! univ]se1 & c en=ce its influ5ce ov] e k9d ( atom ) an imp>tiality t is z a/\nd+ z x is inexorable4 ,moreov]1 ?is weird =ce1 gravitation1 has ?us f> evad$ all man's ef=ts to classify or label x4 ,no man has ! slighte/ inkl+ z to :at gravitation really is4 ,if1 z y glance at ^! l9es1 y %\ld *ance to release y\r hold & all[ ! volume to drop to ! floor1 y w h p]=m$ a miracle :i* no sci5ti/ 9 ! _w c ev5 vaguely expla94 ,z reg>ds our electric tra91 !n1 ! fact t x /&s !re firmly1 held fa/ to ! rails by gravitation1 is 9 reality z great & z inexplicable a m>vel z ! fact t ! electric curr5t gives x propulsion4 ,n only s1 b ! fact t ! tra9 goes =w>d ( its own in]tia1 z we say1 = a "t aft] ! curr5t is %ut (f1 pres5ts to u yet ano!r inexplicable m>vel4 ,x is a fundam5tal prop]ty ( matt]1 we say1 :5 once 9 motion to cont9ue 9 motion until /opp$ by "s c\nt]-=ce2 b t phras+1 expressive ?\gh x be ( a fact ^u :i* s _m physical ph5om5a dep5d1 is 9 no prop] s5se ( ! ^w an explanation4 ,once = all1 !n1 !re is no?+ unique1 no?+ pret]naturally m>vel\s1 ab\t ! ph5om5a ( electricity4 ,& inde$1 x is int]e/+ to note h[ quickly we become accu/om$ to ^! ph5om5a1 & h[ little wond] !y excite s soon z !y cease to be novel4 ,ev5 imag9ative p h long s9ce ceas$ to give ?\ght to ! trolley c>2 & )9 a week ( ! op5+ ( ,new ,york's subway ! av]age man came to reg>d x z mu* z a matt] ( c\rse z if he _h be5 accu/om$ to x f boyhood4 ,& yet1 9 ano!r s5se ( ! ^w1 ! electric motor is a wond]ful contrivance4 ,z an example ( :at man's +5uity c accompli% t[>d trans=m+ ! p[]s ( nature & adapt+ !m to 8 own use1 x is fully entitl$ to be call$ a m>vel4 ,moreov]1 9 ! la/ analysis1 we are z helpless to expla9 ! nature ( electricity z we are to expla9 ! nature ( gravitation4 ,x is only ! proximal ph5om5a ( ! electric curr5t t c be expla9$4 ,^! ph5om5a1 h[ev]1 are full ( int]e/4 ,let u exam9e !m some:at 9 detail1 all[+ !m to lead u back f electric tra9 to p[]-h\se & dynamo1 & f dynamo z f> t[>d ! my/]y ( electric en]gy z pres5t-day sci5ce c guide u4 ,,! ,,me*anism ,,( ,,! ,,dynamo ,if we c\ld look into ! int]ior ( a me*anism 9 connection ) ! trucks b5ea? ! c>1 we %\ld f9d an app>atus consi/+ ess5tially ( coils ( wire adju/$ compactly ab\t an axis1 & closely fitt$ betwe5 ! poles ( a p[]ful electromagnet4 ,^! coils ( wire con/itute :at is call$ an armature4 ,:5 ! curr5t is swit*$ on x passes ?r\gh ?is armature1 z well z ?r\gh ! electromagnet1 & ! mutual attractions & repulsions betwe5 ! magnetic poles & ! electric curr5t 9 ! coils ( wire1 cause ! armature to revolve ) su* trem5d\s en]gy z to move ! tra9--! motion ( its axis be+ transmitt$ to ! axle ( ! c>-:eels by a simple ge>+4 ,all ?is is simple en\gh if we reg>d only ! h[ & n ! :y ( ! ph5om5a4 ,ignor+ ! :y = ! mom5t1 let u seek ! orig9 ( ! curr5t :i*1 by be+ conduct$ ?r\gh ! armature1 has produc$ ! /rik+ effect we h j witness$4 ,?is curr5t rea*es ! c> ?r\gh an ov]head or und]gr\nd wire4 ,all t is ess5tial is t "s conduct+ m$ium1 su* z an iron rail1 or a copp] wire1 %all =m an unbrok5 connection betwe5 ! motor app>atus & ! c5tral dynamo :]e ! p[] is g5]at$--! return circuit be+ made ei!r by ano!r wire or by ! ord9>y rails4 ,! c5tral dynamo 9 "q w be f\nd1 if we visit ! p[]-h\se1 to be a pond]\s affair1 sugge/ive to ! unte*nical m9d ( imp5etrable my/]ies4 ,yet 9 reality x is a device ess5tially ! same 9 con/ruction z ! motor :i* drives ! tra94 ,t is to say1 its unit ( con/ruction consi/s ( a wire-w\nd armature revolv+ on an axis & fitt$ betwe5 ! poles ( an electromagnet4 ,"h1 h[ev]1 ! sequ5ce ( ph5om5a is rev]s$1 = ! armature1 in/ead ( receiv+ a curr5t ( electricity1 is made to revolve by a belt adju/$ to its axis & driv5 by a /eam eng9e4 ,! wire coils ( ! armature ?us made to revolve cut across ! s-call$ l9es ( magnetic =ce :i* connect ! two poles ( ! magnet1 & 9 s do+ g5]ate a curr5t ( induc$ electricity1 :i* fl[s away to rea* 9 due c\rse ! ?ird rail or ! trolley-wire1 & ultimately to propel ! motor4 ,illu/ration3 ,l[] figure copyright$ by ,n4 ,y4 ,edison ,co4 ,,an ,,electric ,,tra9 ,,& ,,! ,,dynamo ,,t ,,propels ,,x4 ,! l[] figure gives an int]ior view ( a p[] h\se ( ! ,manhattan ,elevat$ ,railway ,company4 ,! upp] figure %[s "o ( ! electric eng9es op]at+ on ! ,new ,york ,c5tral ,l9es j outside ( ,new ,york4 ,! p[] is convey$ to ! eng9e by a ?ird rail cle>ly %[n 9 ! picture4 ,x is h>dly necess>y to /ate t 9 actual practice ?is g5]at+ dynamo is a complex /ructure4 ,! armature is a complex s]ies ( coils ( wire2 ! electromagnets surr\nd+ ! armature are sev]al or _m2 & !re is an elaborate sy/em ( s-call$ commutators ?r\gh :i* ! curr5ts ( electricity--:i* w\ld o!rwise oscillate z ! revolv+ coil cuts ! l9es ( magnetic =ce 9 opposite directions--are made to fl[ 9 "o direction4 ,b details aside1 ! f\ndation facts ^u :i* ev]y?+ dep5ds are 7#a7 t a coil ( wire :5 =c$ to move s t x cuts across ! l9es ( =ce 9 any magnetic field develops a s-call$ induc$ curr5t ( electricity2 & 7#b7 t su* an induc$ curr5t possesses p[] ( magnetic attraction & repulsion4 ,^! facts 7 discov]$ m ?an sixty ye>s ago1 & c>efully /udi$ by ,mi*ael ,f>aday1 ,joseph ,h5ry1 & o!rs4 ,f>aday f\nd t su* an induc$ curr5t c\ld be produc$ n m]ely ) ! aid ( an iron magnet1 b ev5 by caus+ a wire to cut ! l9es ( =ce t ev]y:]e connect ! nor? & s\? poles ( ! e>?1--! e>? be+ inde$1 z ,william ,gilb]t long ago demon/rat$1 v]itably a gigantic magnet4 ,moreov]1 ^! relations are reciprocal2 s t if a wire ?r\gh :i* a curr5t ( electricity is pass+ is plac$ across a magnetic field1 ! wire is impell$ to move 9 a plane at "r angles to ! direction ( ! l9es ( =ce4 ,x is =cibly ?ru/ aside4 ,?is side-?ru/ act+ on coils ( wire is :at produces ! revolution ( ! armature ( ! electric motor4 ,,! ,,orig9 ,,( ,,! ,,dynamo ,! v fir/ /udies t _h to d ) ! mutual relations ( electricity & magnetism 7 made by ,hans ,*ri/ian ,o]/$1 ! ,dane1 z e>ly z #ahae4 ,he discov]$ t a magnetic ne$le is influ5c$ by ! passage ne> x ( a curr5t ( electricity1 demon/rat+1 !re=e1 t ! electric curr5t 9 "s way invades ! m$ium surr\nd+ any conductor along :i* x is pass+4 ,o]/$'s exp]im5ts 7 repeat$1 & "s new ph5om5a obs]v$ by ! ,fr5*man ,&r ,m>ie ,ampre & ,dom9ique ,franois ,arago4 ,arago con/ruct$ an int]e/+ device1 9 :i* a metal disk 0 made to revolve 9 ! pres5ce ( a curr5t ( electricity2 b nei!r he nor anyone else at ! "t 0 able to expla9 ! ph5om5on4 ,9 #ahbd an advance 0 made ?r\gh ! con/ruction ( ! fir/ electric magnet by ,/urgeon4 ,hi!rto x _h n be5 kn[n t a magnet c\ld be made artificially1 except by contact ) a previ\sly exi/+ magnet4 ,/urgeon %[$ t any core ( iron may be r5d]$ magnetic if w\nd ) a conduct+ wire1 ?r\gh :i* a curr5t ( electricity is pass$4 ,! exp]im5ts ?us inaugurat$ 7 foll[$ up 9 ,am]ica by ,joseph ,h5ry ( ,albany :o made enorm\s electromagnets1 capable ( su/a9+ great weights4 ,"o ( 8 magnets1 op]at$ by a s+le cell1 0 able to lift six hundr$ & fifty p\nds ( metal4 ,x 0 ?is app>atus :i* 0 subsequ5tly to make possible ! utilization ( electricity z a work+ =ce1 b z yet no "o suspect$ its possibilities 9 ?is direction4 ,x rema9$ = ,mi*ael ,f>aday1 9 #ahca1 to make ! f9al exp]im5t :i* laid ! secure f\ndation = ! new sci5ce ( electrodynamics4 ,f>aday con/ruct$ a t9y app>atus1 consi/+ ( a magnet betwe5 ! poles ( :i* a metal disk 0 plac$ 9 su* a way t x c\ld revolve on an axis1 ! disk be+ connect$ ) a wire convey+ an electric curr5t4 ,! details z to ?is mo/ +5i\s me*anism ne$ n be giv5 "h4 ,suffice x t ,f>aday demon/rat$ ! int]relations ( magnetism & electricity & ! possibility ( caus+ a metal disk to revolve ?r\gh ?is mutual int]action4 ,9 s do+ he con/ruct$ ! fir/ dynamo-electric ma*9e4 ,9 8 h&s x 0 a m]e laboratory toy1 b ! pr9ciples involv$ 7 fully elaborat$ by ! orig9al exp]im5t]1 & /at$ 9 precise language :i* mod]n inve/igators h n be5 able to improve ^u4 ,sev]al decades elaps$ aft] ,f>aday's initial exp]im5t be=e ! ph5om5a ( magneto-electricity 7 prov$ to h any consid]able comm]cial significance4 ,a va/ am\nt ( +5uity 0 requir$ to devise a me*anism :i* c\ld advantage\sly utilize ! pr9ciple 9 "q = comm]cial purposes4 ,inde$ ! e>ly exp]im5t]s did n at once get ^u ! "r track1 z _! ef=ts 7 influ5c$ disadvantage\sly by an attempt to foll[ ! pr9ciple ( ! /eam eng9e4 ,"s int]e/+ me*anisms 7 devis$ :]eby ! motion ( an armature 9 be+ drawn t[>d an electromagnet c\ld be translat$ into rot>y motion ?r\gh ! use ( crank-%afts & ev5 ( beams1 precisely comp>able to ^? employ$ 9 ! /eam eng9e4 ,su* devices work$ ) a comp>atively l[ degree ( effici5cy & 7 totally ab&on$ s soon z ! idea ( gett+ rot>y motion directly f ! magnet or armature 0 made feasible4 ,! names ( ,saxton1 ,cl>ke1 ,woolri*1 ,:eat/one1 & ,w]n] ,siem5s are intimately connect$ ) ! e>ly ef=ts at utilization ( magneto-electric p[]4 ,! %uttle-w\nd armature ( ,siem5s1 inv5t$ 9 #ahed1 m>k$ an important progressive /ep4 ,,p]fect+ ,,! ,,dynamo ,! fir/ sep>ately excit$ dynamos 7 con/ruct$ by ,dr4 ,h5ry ,wilde1 ,f4,r4,s41 betwe5 #ahfc & #ahfe1 & ?is inv5tion pav$ ! way = rapid progress4 ,9 #ahff-g ,v>ley1 ,siem5s1 ,:eat/one1 & ,ladd con/ruct$ ma*9es ) sev]al iron electromagnets1 self-excit$1 :i* 7 describ$ z dynamo-electric ma*9es1 a t]m aft]w>d contract$ to dynamos4 ,9 #ahfg ,dr4 ,wilde improv$ ! armature by introduc+ sev]al coils arrang$ ar\nd a cyl9d]2 ! curr5t f a few ( ! coils 0 rectifi$ & us$ to excite ! field magnet1 :ile ! ma9 curr5t z giv5 (f by ! re/ ( ! coils 0 tak5 (f by r+-contacts1 ! ma*9e be+ a self-excit+1 alt]nat+-curr5t dynamo4 ,illu/ration3 ,,wilde',s ,,sep>ately ,,excit$ ,,dynamo4 ,dr4 ,wilde inv5t$ & pat5t$ 7#ahfc-e7 ! fir/ sep>ately excit$ dynamo1 ) :i* he demon/rat$ t ! feeble curr5t f a small magneto-electric ma*9e w\ld1 by ! exp5diture ( me*anical p[]1 produce curr5ts ( great /r5g? f a l>ge dynamo4 ,! ,italian1 ,picnotti1 9 #ahfd inv5t$ a r+ armature :i*1 al?\gh provid$ ) tee? 0 w\nd ) coils 9 su* a way z to obta9 a v uni=m curr5t2 b ! practical introduction ( ! cont9u\s-curr5t ma*9es dates f #ahgj1 :5 ,gramme re-inv5t$ ! r+ & gave x ! =m :i* is /ill 9 vogue4 ,von ,alt5eck 9 #ahgc conv]t$ ! ,siem5s %uttle armature along ! same l9es & s introduc$ ! drum arrangem5t :i* has s9ce be5 v ext5sively adopt$4 ,?us ?r\gh ! ef=ts ( a great numb] ( work]s ! idea ( utiliz+ electromagnetic en]gy = ! purposes ( ! practical work] came to be a reality4 ,numb]less ma*9es h be5 made diff]+ only z to details t ne$ n deta9 u "h4 ,ev]yone is famili> ) sundry applications ( ! dynamo to ! purposes ( to-day's appli$ sci5ce4 ,x mu/ be und]/ood1 ( c\rse1 t ! am\nt ( electricity g5]at$ 9 any dynamo is precisely measurable1 & t by no possibility c\ld ! en]gy ?us develop$ exce$ ! en]gy requir$ to move ! coils ( wire4 ,7 x o!rwise ! great law ( ! cons]vation ( en]gy w\ld be ov]?r[n4 ,9 actual practice1 ( c\rse1 !re is loss ( en]gy 9 ! transaction4 ,! curr5t ( electricity t fl[s f ! v be/ dynamo repres5ts consid]ably less work+ p[] ?an is exp5d$ by ! /eam eng9e 9 =cibly revolv+ ! armature4 ,9 ! e>ly days ( exp]im5ts ! loss 0 s great z to be comm]cially prohibitive4 ,) ! p]fect$ mod]n dynamo ! loss is n great] ?an fifte5 p] c5t2 b ev5 ?is1 x w be not$1 makes electricity a relatively exp5sive p[] z comp>$ ) /eam1--except1 inde$1 :]e "s natural p[]1 l ! ,falls ( ,niag>a1 c be utiliz$ to drive ! armature4 ,a ,,my/]i\s ,,me*anism ,! effici5cy ( ! mod]n dynamo is due l>gely to ! fact t :5 ! poles ( ! magnet are made to face ea* o!r1 ! l9es ( magnetic =ce pass+ betwe5 ^! poles are conc5trat$ into a n>r[ compass4 ,) ! ord9>y b> magnet1 z ev]yone is aw>e1 ^! l9es ( =ce circle out 9 e direction f ! poles 9 an almo/ inf9ite numb] ( loops1 all conv]g+ at ! poles1 & becom+ relatively sep>at$ at ! equator 9 a mann] :i* may be graphically illu/rat$ by ! l9es ( longitude drawn on an ord9>y globe4 ,x is obvi\s t ) a magnet ( su* con/ruction only a small proportion ( ! l9es ( magnetic =ce c\ld be utiliz$ 9 g5]at+ electricity4 ,b1 z already m5tion$1 :5 ! magnet is s curv$ t its poles face ea* o!r1 ! l9es ( =ce1 in/ead ( widely div]g+1 pass f pole to pole almo/ 9 a direct /ream4 ,! /r5g? ( ?is magnetic /ream may be increas$ almo/ indef9itely by w9d+ ! iron core ( ! magnet ) ! coil ( wire ?r\gh :i* ! electric curr5t is pass$1 ?us con/itut+ ! electromagnet :i* has replac$ ! old p]man5t magnet 9 all mod]n comm]cial dynamos4 ,illu/ration3 ,,! ,,evolution ,,( ,,! ,,dynamo4 ,fig4 #a4--;,a small example ( ! orig9al comm]cial =m ( ! drum armature ma*9e1 pat5t$ 9 #ahgc by ,dr4 ,w]n] ,siem5s & ,f4 ,von ,hefn] ,alt5eck4 ,! armature is a developm5t ( ! ,siem5s %uttle =m ( #ahef1 & gives a ne>ly cont9u\s curr5t4 ,fig4 #b4--;,an e>ly exp]im5tal dynamo4 ,fig4 #c4--;,f]ranti's orig9al dynamo1 pat5t$ 9 #ahhb-ahhc4 ,! field magnets are /ation>y & consi/ ( two sets ( electro-magnets ea* ) #af project+ pull pieces1 betwe5 :i* ! armature revolves4 ,fig4 #d4--,! gigantic rot>y conv]t]s ( ! ,manhattan ,elevat$ ,railway4 ,an electromagnet may be suffici5tly p[]ful to lift tons ( iron4 ,! =ce x ex]ts1 !re=e1 is v tangible 9 its results4 ,yet x seems my/]i\s1 because s _m sub/ances are unaffect$ by x4 ,y may place y\r head1 = example1 betwe5 ! poles ( ! mo/ p[]ful magnet )\t exp]i5c+ any s5sation or be+ 9 any obvi\s way affect$4 ,y may wave y\r h& across ! l9es ( =ce z freely z y may wave x any:]e else 9 space4 ,app>5tly no?+ is !re4 ,b 7 y to attempt to pass a dumb-bell or a b> ( iron across ! same space1 ! unse5 magnetic =ce w\ld wr5* x f y\r grasp ) a p[] s irresi/ible z to be awe-inspir+4 ,simil>ly1 ! armature1 :5 its coils ( wire are adju/$ betwe5 ! poles ( ! magnet1 is held 9 a vise-l grip by ! invisible b pot5t l9es ( magnetic =ce :i* t5d to make x revolve4 ,x requires a trem5d\s exp5diture ( en]gy--suppli$ by ! /eam-eng9e or by wat] p[]--to enable ! coil$ wires ( ! g5]at+ armature to /em ! curr5t ( magnetic =ce1 :i* is virtually :at is done :5 ! armature revolves 9 su* a way z to produce electrical en]gy4 ,"p ( ! me*anical en]gy ?us exp5d$ is trans=m$ into heat & dissipat$ into space2 b ! ma9 portion is c>ri$ (f1 z we h se51 ?r\gh ! coil$ wires ( ! armature 9 ! =m ( :at we t]m ! curr5t ( electricity1 to be re-trans=m$ 9 due c\rse into ! me*anical en]gy t moves ! c>4 ,x appe>s1 !n1 t ! ph5om5a ( ! electric dynamo dep5d ^u ! curi\s relations t exi/ betwe5 magnetism & electricity4 ,grant$ ! ess5tial facts ( magneto-electric induction1 all ! ph5om5a ( ! dynamo are explicable4 ,b h[ expla9 ^! facts !mselves8 ,:y is an electric curr5t g5]at$ 9 a coil ( wire mov+ 9 a magnetic field8 ,& :y is a wire c>ry+ a curr5t ( electricity1 :5 plac$ across a magnetic field1 impell$ to move at "r angles to ! l9es ( magnetic =ce8 ,no ?\ghtful p]son c consid] ! subject )\t ask+ ^! que/ions4 ,b z yet no def9itive answ] is =?com+4 ,"s sugge/ive half-explanations1 bas$ on an assum$ condition ( torsion or /ra9 9 ! e!r1 h be5 attempt$1 b !y c h>dly be call$ m ?an sci5tific guesses4 ,mean:ile1 x may be und]/ood t ! mutual relations ( ! magnetic & electrical =ces j ref]r$ to are n at all dep5d5t ^u ! mann] 9 :i* ! electric curr5t is g5]at$4 ,! magneto-electric motor may be op]at$ z well ) a *emical batt]y z ) su* a me*anical g5]at+ dynamo z has j be5 describ$4 ,! /orage-batt]ies :i* h be5 employ$ 9 "s /reet railways & ^? :i* propel ! electric cabs ab\t our city /reets furni% cases 9 po9t4 ,! only reason ^! are n m g5]ally employ$ is t ! /orage batt]y has n yet be5 p]fect$ s t x c produce a l>ge supply ( electricity 9 proportion to its weight1 & produce x economically4 ,x ,,niag>a ,,9 ,,h>ness ,h>ness+ ,niag>a--! phrase has be5 a commonplace = a g5]ation2 b until v rec5tly inde$ x 0 no?+ m ?an a phrase4 ,almo/ s9ce ! "t :5 ! ,falls 7 fir/ view$ by a :ite man ! idea ( utiliz+ _! p[]s has be5 dream$ (4 ,b until our own day--until ! la/ decade--sci5ce _h n %[n a way 9 :i* ! great curr5t c\ld be economically %ackl$4 ,a few puny mill-:eels h inde$ revolv$ = ?irty ye>s or s1 b ^! 7 ( no great] significance ?an ! ?\s&s ( o!rs driv5 by m\nta9 /reams or by ! curr5ts ( ord9>y riv]s4 ,b ab\t a decade ago ! eng9e]+ skill ( ! _w 0 plac$ 9 commission1 & to-day ,niag>a is fairly 9 h>ness4 ,if y h ev] se5 ,niag>a--& :o has n se5 x8-y mu/ h be5 /ruck ) ! metamorphosis t comes ov] ! /ream ab\t half a mile above ! falls4 ,above ?is po9t ! riv] fl[s ) a smoo? sluggi% curr5t4 ,only fifte5 feet h ! wat]s sunk 9 _! placid fl[+ s9ce !y left ,lake ,erie4 ,b n[ 9 ! c\rse ( half a mile !y are pit*$ d[n m ?an two hundr$ feet4 ,if y foll[ ! /ream t[>d ?is decl9e y %all see x und]go a m>vel\s *ange4 ,( a sudd5 ! placid wat]s seem to feel ! beckon+ ( a new impulse4 ,caught ) ! wit*]y ( a new motion1 !y g swirl+ ahead ) unwont$ lilt & plunge1 call+ out ) ribald voices t come to ! e> 9 an in*oate *orus ( /rid5t1 high-pit*$ murmur+s4 ,ea* wavelet seems eag] to hurry on to ! full fruition ( ! cat>act4 ,x la%es ) angry foam ea* *ance ob/ruction1 & gurgles its disapproval 9 ev]-*ang+ measures4 ,ev5 to ! mo/ ?\ghtless obs]v] ! mighty curr5t ?us un*a9$ atte/s ! sublimity ( almo/ irresi/ible p[]4 ,c\ld a mighty mill-:eel be adju/$ 9 t dizzy curr5t1 :at labors might x n p]=m8 ,five million tons ( wat] ru% d[n ?is decl9e ea* h\r1 we are told2 & ! =ce t ?us goes to wa/e is z if ?ree million unbridl$ horses exhau/$ _! /r5g? 9 ceaseless plung+4 ,?is e/imate may be only a guess1 b x matt]s n :e!r x be high or l[2 all e/imates are futile1 all comp>isons inadequate to convey ev5 a vague conception ( ! maje/y ( p[] ) :i* ! mighty wat]s ru% on to _! f9al plunge into ! abysm4 ,x is "h1 y might well suppose1 :]e ! appall+ =ce ( ! curr5t is made s tangible1 t man w\ld place ! fett]s ( 8 h>ness1 mak+ ! madcap curr5t subject to 8 w4 ,y w p]haps m ?an half expect to see gigantic me*anisms ( man's con/ruction built out ov] ! rapids or across ! face ( ! cat>act--s mu* has be5 said ( /heticism v]sus comm]cialism 9 connection ) ! attempt to utilize ,niag>a's p[]4 ,b :atev] y\r fe>s 9 ?is reg>d1 !y w n be realiz$4 ,inspect ! rapids & ! falls z y may1 y w see no evid5ce t man has tamp]$ ) _! pri/9e fre$om4 ,subtl] means h be5 employ$ to tame ! wild /e$4 ,! mad waves t g da%+ d[n ! rapids are z free & untrammel$ to-day z !y 7 :5 ! wild ,indian 0 ! only witness ( _! tempe/u\s activity4 ,su* portions ( ! curr5t z rea* ! rapids h full lic5se to pass on untrammel$1 pay+ no toll to man4 ,! wat] :i* is made to pay tribute is drawn f ! /ream up !re above ! rapids1 :]e x lies placid & z yet un/irr$ by ! beckon+ incl9e4 ,to see ,niag>a 9 h>ness1 !n1 y mu/ leave ! cat>act & ! rapids & pass a full mile up ! /ream :]e ! great riv] looks z calm z ! ,hudson or ! ,mississippi1 & :]e1 "u ord9>y conditions1 n ev5 ! s\nd ( ! falls comes to y\r e>4 ,prosaic en\gh x seems to obs]ve "h no?+ m />tl+ ?an a broad cul de sac ( /agnant wat]1 l ! beg9n+ ( a broad canal1 ext5d+ 9 = a few hundr$ y>ds only f ! ma9 /ream2 its wat]s sil5t1 curr5tless1 seem+ly impot5t4 ,?is /agnant pool1 !n1 n ! :irl+ curr5t bel[1 is to furni% ! wat] ^: res]ve =ce ( en]gy ( position is drawn ^u to s]ve man's gre$y purpose4 ,com+ f ! rapids & cat>act to ?is /agnant canal1 y seem to /ep f ! realm ( poetic beauty to ! sordid realities ( ! "w-a-day _w4 ,( a tru? x w\ld seem t h>ness+ ,niag>a is b a f>-fet*$ metaphor4 ,,)9 ,,! ,,p[]-,,h\se ,& yet if y w turn aside f ! canal & ent] "o ( ! long1 l[ build+s t flank x on ei!r side1 y w soon be made to feel t ! metaphor 0 amply ju/ifi$4 ,little z !re 0 ext]iorly to sugge/ x1 y are ent]+ a fairyl& ( appli$ sci5ce1 & )9 ^! pla9 walls y %all witness evid5ces ( ! +5uity ( man t %\ld appeal sc>cely less to y\r imag9ation ?an ! sight ( ! cat>act itself 9 all its sublimity ( p[]4 ,= )9 ^! walls1 by a miracle ( mod]n sci5ce1 ! pot5tial en]gy :i* resides 9 ! wat] ( ! canal is trans=m$ into an electrical curr5t :i* is s5t out ov] a network ( wires to di/ant cities to p]=m a ?\s& necromantic tasks1--propell+ a /reet c> 9 "o place1 effect+ *emical decompositions 9 ano!r2 turn+ ! :eels ( a factory "h & light+ ! /reets ( a city !re2 9 %ort1 subs]v+ ! practical ne$s ( man 9 devi\s & wond]ful ways4 ,ev5 z y gaz$ disda9fully at ! /agnant canal1 its wat]s1 miracul\sly trans=m$1 7 propell+ ! trolley c>s along ! br9k ( ! cliff ov] !re on ! ,canadian %ore1 & at ! same "t 7 turn+ ! :eels 9 _m a factory 9 ! di/ant city ( ,buffalo4 ,aft] all1 !n1 ! quiet pool ( wat] 0 n s prosaic z x seem$4 ,z y /& 9 ! build+ :]e ?is wond]ful trans=mation ( p[] is effect$1 ! noble simplicity ( ! vi/a height5s ! my/]y4 ,! mo/ significant ?+ t /rikes ! eye is a r[ ( great mu%room-l affairs1 = all ! _w l giant tops1 t /& sp9n+--& sp9n+4 ,^! great tops are ab\t a doz5 feet 9 diamet]4 ,!y are :irl+1 s we are told1 at a rate ( two hundr$ & fifty revolutions p] m9ute4 ,h\r aft] h\r !y sp9 on1 nev] v>y+ 9 spe$1 nev] falt]+2 day & night are alike to !m1 & "o day is l ano!r4 ,!y are z ceaselessly active1 z unwe>y+ z ,niag>a itself1 ^: p[] !y symbolize2 &1 l ! great ,falls1 !y murmur exult+ly z !y "w4 ,illu/ration3 ,,view ,,9 ,,"o ,,( ,,! ,,p[] ,,h\ses ,,at ,,niag>a4 ,ea* ( ! top-l dynamos g5]ates #ejjj horse-p[]4 ,! giant tops :i* ?us seem to bid defiance to ! laws ( motion are 9 reality electric dynamos1 no diff]5t 9 pr9ciple f ! electric g5]ators ) :i* "s visit to a /reet-c> p[]-h\se has d\btless made y famili>4 ,! anomal\s feature ( ^! dynamos--9 addition to _! size--is f\nd 9 ! fact t !y revolve on a v]tical %aft :i* ext5ds d[n into a hole 9 ! e>? = m ?an a hundr$ feet1 & at ! o!r end ( :i* is adju/$ a gigantic turb9e wat]-:eel4 ,wat] f ! canal is suppli$ ?is great turb9e :eel ?r\gh a /eel tube or p5/ock1 sev5 feet 9 diamet]4 ,z ! turb9e revolves "u /ress ( ?is mighty column ( wat]1 ! long %aft revolves ) x1 ?us turn+ ! electric g5]ator at ! o!r end ( ! %aft--! g5]ator at :i* we are look+1 & :i* we h lik5$ to a giant top--)\t ! int]position ( any =m ( ge>+ :atev]4 ,to ga9 a vivid m5tal picture ( ! app>atus1 we mu/ take an elevator & desc5d to ! l[] regions :]e ! turb9e :eel is 9 op]ation4 ,z we pass d[n & d[n1 our eyes all ! "t fix$ on ! v]tical revolv+ %aft1 :i* is visible ?r\gh a network ( b>s & grat+s1 x becomes increas+ly obvi\s t to speak ( ?is %aft z /&+ 9 a hole 9 ! gr\nd is to d ! situation v scant ju/ice4 ,a mu* tru] picture w be conceiv$ if we ?9k ( ! entire p[]-h\se z a mon/] build+1 ab\t two hundr$ feet high1 all b ! top /ory be+ und]gr\nd4 ,:at corresponds to ! gr\nd floor ( ! ord9>y build+ is locat$ "o hundr$ & fifty feet bel[ ! e>?'s surface2 & x is ! top /ory :i* we ent]$ f ! /reet level1 ?us precisely rev]s+ ! ord9>y conditions4 ,,p5/ocks ,,& ,,turb9es ,z we desc5d n[ & rea* at la/ ! l[e/ floor ( ! build+1 we /ep out into a long n>r[ room1 ! ma9 surface ( :i* is tak5 up ) a s]ies ( gigantic turnip-%ap$ me*anisms1 ea* "o hav+ a revolv+ %aft at its axis2 :ile f its side projects outw>d & !n upw>d a sev5-foot /eel tube1 = all ! _w l ! funnel ( a /eam%ip4 ,?is seem+ funnel--te*nically t]m$ a p5/ock--is 9 reality ! great tube ?r\gh :i* ! massive column ( wat] f9ds access to ! turb9e :eel1 :i* ( c\rse is incas$ )9 ! turnip-%ap$ me*anism at its base4 ,z y /& !re beside ?is great /eel me*anism a s5se ( wond]m5t & ( utt] helplessness takes possession ( y4 ,z y glance d[n ! hall at ?is s]ies ( great wat] conduits1 & /ra9 y\r eyes upw>d 9 ! endeavor to foll[ ! great funnel to its v end1 an oppressive s5se ( ! irresi/ible weight ( ! great column ( wat] x supports comes to y1 & y c sc>cely avoid a feel+ ( appreh5sion4 ,suppose "o ( ! great tubes 7 to bur/8--we %\ld all be dr[n$ l rats 9 a hole4 ,!re is small dang]1 to be sure1 ( su* a cont+5cy2 b x is well wor? :ile to h /ood ?us away d[n "h at ! he>t ( ! great p[]-h\se to h ga9$ an aw$ s5se ( :at man c accompli% t[>d rival+ ! wond]s ( nature4 ,to h /ood an h\r ago on ! ice bridge at ! foot ( ! mo/ trem5d\s cat>act 9 ! _w1 :]e ,nature exhau/s h] p[]s amid/ ! mad ru% & ro> ( see?+ wat]s2 & n[ to /& b5ea? ?is o!r column ( wat] :i* effects a no less wond]ful trans=mation ( en]gy1 s]5ely1 sil5tly1--is to h run su* a gamut ( emotions z few o!r h\rs 9 all y\r life c h 9 /ore = y4 ,a ,,miracul\s ,,trans=mation ,,( ,,en]gy ,!re are elev5 ( ^! great turb9e me*anisms1 ea* ) a supply+ funnel ( wat] & a revolv+ %aft ext5d+ upw>d to its companion dynamo1 9 ! room 9 :i* we /&4 ,en]gy repres5t+ fifty-five ?\s& horse-p[] is incessantly trans=m$ & made available = man's use 9 ! subt]ranean build+ 9 :i* we /&4 ,& !re is n a p\nd ( coal1 n a lick ( flame1 n an atom ( /eam involv$ 9 ! trans=mation4 ,!re are no du/-grim$ labor]s2 !re is no gl>e ( furnace1 no gl[ ( heat1 no /ifl+ odor ( burn+ fuel2--!re is only ! re/ful hum ( ! ma*9]y t responds to ! ceaseless fl[ ( ! sil5t & invisible wat]s4 ,day & night ! mighty riv] "h pulls away at its turb9e h>ness2 & man1 hav+ once adju/$ t h>ness1 may take 8 ease & enjoy ! fruits ( 8 +5uity4 ,z we return n[ to ! top ( ! build+1 we %all view ! sp9n+ dynamos ) r5ew$ int]e/1 & a few facts reg>d+ _! output ( en]gy may well claim our att5tion4 ,9 _! pr9ciple ( action1 z we h se51 all dynamos are alike1--dep5d+ ^u ! mutual relations betwe5 ! wire-w\nd armature & a magnetic field4 ,9 ! pres5t case ! magnets are made to revolve & ! armatures are /ation>y1 b ?is is a m]e detail4 ,!re is "o feature ( ^! dynamos1 h[ev]1 :i* is ( great] importance1--! fact namely t !y op]ate )\t commutators1 & !re=e produce alt]nat+ curr5ts4 ,?is fact has an important be>+ ^u ! di/ribution ( ! curr5t4 ,ea* ( ! dynamos be=e u g5]ates ! equival5t ( five ?\s& horse-p[] ( en]gy4 ,!re are elev5 su* dynamos "h be=e u2 !re are t5 m 9 ! p[]-h\se on ! o!r side ( ! canal1 giv+ a total ( "o hundr$ & five ?\s& horse-p[] = ?is s+le plant2 & !re are five su* plants n[ 9 exi/5ce or 9 c\rse ( con/ruction to utilize ! wat]s ( ,niag>a1 ?ree be+ on ! ,canadian %ore4 ,:5 9 full op]ation ! aggregate output ( ^! plants w be six or sev5 hundr$ ?\s& horse-p[]4 ,,subt]ranean ,,tail-,,races ,z we /ep f ! door ( ! p[]-h\se & /& aga9 beside ! canal ^: wat]s produce ! wond]ful effects we h witness$ 9 imag9ation1 "o "q rema9s to be answ]$3 ,:at becomes ( ! wat] aft] x has pass$ ?r\gh ! turb9e :eels d[n !re 9 ! dep?s8 ,! answ] is simple3 ,all ! wat] f ! v>i\s turb9es fl[s away into a great subt]ranean canal :i* passes d[n b5ea? ! city ( ,niag>a ,falls1 & dis*>ges f9ally at ! level ( ! rapids a few hundr$ y>ds bel[ ! ,falls4 ,! con/ruction ( ?is subt]ranean canal w\ld 9 itself h be5 consid]$ a great eng9e]+ feat a few decades ago2 b ( late ye>s m\nta9 tunnels1 su* subt]ranean railways z ! ,london tube sy/em & tunnels b5ea? riv]s h robb$ su* /ructures ( _! my/]y4 ,x may be add$ t ano!r su* subt]ranean canal1 to s]ve z a tail-race = "o ( ! new ,canadian plants1 ext5ds b5ea? ! cat>act itself1 dis*>g+ n f> f ! c5tre ( ! ,horse%oe ,falls4 ,ano!r ( ! p[] companies utilizes ! wat] ( ! old surface canal :i* ext5ds to ! br9k ( ! gorge "s di/ance bel[ ! ,falls4 ,yet ano!r company on ! ,canadian side conveys wat] f f> above ! rapids 9 a gigantic clos$ tube to ! br9k ( ! gorge j bel[ ! ,canadian ,falls1 above ! po9t :]e _! p[]-h\se is locat$4 ,b ! pr9ciple involv$ is ev]y:]e ! same4 ,! idea is m]ely to utilize ! weight ( fall+ wat]4 ,! wat] ( ,niag>a ,riv] is ( c\rse no diff]5t f any o!r body ( wat] ( equal size4 ,x is m]ely t its unique position gives ! eng9e] an easy opportunity to utilize ! pot5tial en]gy t resides 9 any body ( wat]--or1 = t matt]1 9 any o!r physical sub/ance--ly+ at a high level4 ,9 due c\rse1 d\btless1 o!r bodies ( wat]1 su* z m\nta9 lakes & m\nta9 /reams w be simil>ly put into electrical h>ness4 ,! electrical feature is ( c\rse ! "o t mo/ appeals to ! imag9ation4 ,b x may be well to recall t ! ultimate s\rce ( all ! p[] 9 "q is gravitation4 ,p fond ( philosophical gymna/ics may reflect ) int]e/ t1 accord+ to ! newe/ !ory1 gravitation itself is1 9 ! la/ analysis1 an electrical ph5om5on--a reflection :i*1 x w be not$1 leads ! m9d ?r\gh a v curi\s cycle4 ,,! ,,effect ,,on ,,! ,,falls ,mu* solicitude has be5 express$ z to ! possible effect1 ^u ! ,falls !mselves1 ( ?is )drawal ( wat]4 ,= ! pres5t1 x is admitt$1 !re is no visible effect2 & to ! casual obs]v] x may seem t almo/ any quantity ( wat] ! p[]-h\ses are likely to ne$ might be )drawn )\t s]i\sly m>r+ ! wond]ful cat>act4 ,b ! /ati/ics suppli$ by ! p[] companies1 tak5 9 connection ) e/imates z to ! bulk ( wat] t passes ov] ! ,falls1 d n support ?is optimi/ic view4 ,tak+ :at seems to be a reasonable e/imate = a basis ( computation x w\ld appe> t :5 ! p[]-h\ses n[ rapidly approa*+ completion are 9 full op]ation1 ! total )drawal ( wat] f ! /ream w repres5t a v appreciable fraction ( its entire bulk--"o-tw5ty-fif? at ! v lea/1 p]haps z mu* z "o-t5?4 ,su* a dim9ution z ?is w by no means ru9 ! ,falls1 yet x w\ld seem z if x mu/ s5sibly affect !m1 p>ticul>ly at "s places ne> ,goat ,isl&1 :]e ! wat] fl[s at pres5t 9 a v %all[ /ream4 ,be t z x may1 h[ev]1 ! p[]-h\ses are !re1 & x is probable t _! numb] w be add$ to z ye>s g on4 ,:e!r comm]cialism or /heticism w w9 9 ! end1 x rema9s = ! legislators ( ! future to decide4 ,mean:ile1 x is gratify+ to reflect t = ! pres5t ! ,falls reta9 _! pri/9e beauty1 ev5 ?\gh "p ( ! wat] t is _! normal due is turn$ aside & made to d s]vice = man 9 ano!r way4 ,!re is only "o reason :y ! ,falls h escap$ desecration s long z !y h2 t reason be+ ! v practical "o t until q rec5tly man has n kn[n h[ to utilize _! p[]s to advantage4 ,! ef=t 0 inde$ made1 a full g5]ation ago1 ?r\gh ! con/ruction ( ! canal lead+ f ! upp] riv] to ! bluffs ov]look+ ! gorge bel[ ! cat>act4 ,"h a few mill-:eels 7 set :irl+1 & a t9y fraction ( ! pot5tial en]gy ( ! wat] 0 utiliz$4 ,!re 0 no me*anical difficulty involv$ 9 ! utilization ( ?is p[]4 ,mill-:eels are a famili> old-"t device1 & ev5 ! turb9e :eel is mod]n only 9 a relative s5se ( ! ^w4 ,& x mu/ be und]/ood t ! turb9e wat]-:eel utilizes ! greate/ proportion ( ! p[] ( fall+ wat] ( any contrivance z yet kn[n to me*anics4 ,x 0 possible1 !n1 to utilize ! wat] ( ,niag>a ) full effectiv5ess fifty ye>s ago1 s f> z ! direct action ( ! wat]-:eel ^u ma*9]y ne> at h& 0 conc]n$4 ,! sole difficulty lay 9 ! fact t only a small am\nt ( ma*9]y c be plac$ 9 any "o location4 ,! real problem 0 n h[ to produce ! p[]1 b h[ to transmit x to a di/ance4 ,,! ,,transmission ,,( ,,p[] ,= fifty ye>s me*anical eng9e]s h look$ envi\sly ^u un%ackl$ ,niag>a1 & h /riv5 to solve ! problem ( transmitt+ its p[]4 ,x 7 easy en\gh to h>ness ! great ,fall1 b futile to d s1 s long z ! p[] g5]at$ mu/ be us$ 9 ! imm$iate vic9ity4 ,s1 _m s*emes = transmitt+ p[] 7 tri$ "o aft] ano!r1 & z (t5 laid aside4 ,!re 0 "o objection to ev5 ! be/ ( !m--! co/4 ,at "o "t x 0 ?\ght t compress$ air might solve ! problem4 ,b repeat$ exp]im5ts did n ju/ify ! hope4 ,!n x 0 believ$ t ! /orage batt]y might be made available4 ,! /orage batt]y1 x might be expla9$1 does n really /ore electricity 9 ! s5se 9 :i* ! ,leyd5 j>1 = example1 /ores x4 ,r is x to be lik5$ to an ord9>y voltaic cell1 ! *emical +r$i5ts ( :i* h be5 r5d]$ active by ! passage ( ! electric curr5t4 ,! active +r$i5ts ( ! /orage batt]y are usually lead comp\nds1 :i* ?r\gh action ( ! electric curr5ts h be5 decompos$ & plac$ 9 a /ate ( *emical in/ability4 ,! dissociat$ molecule ( ! lead comp\nd1 :5 p]mitt$ to reunite ) ! atoms ) :i* x 0 =m]ly associat$1 w give up electrical en]gy4 ,su* a /orage batt]y might readily be *>g$ ) electricity g5]at$ at ,niag>a ,falls4 ,x might !n be convey$ to any "p ( ! _w1 &1 its poles be+ connect$1 ! *>ge ( electricity w\ld be made available4 ,su* /orage batt]ies are 9 common use 9 connection ) electric automobiles1 z we h se54 ,b ! great difficulty is t !y are enorm\sly heavy 9 proportion to ! am\nt ( electricity t !y c g5]ate2 !re=e1 _! transportation is difficult & exp5sive4 ,9 practice x is *eap] to produce electricity ?r\gh ! op]ation ( a /eam eng9e 9 a di/ant city ?an to transmit ! electricity ) ! aid ( a /orage batt]y f ,niag>a4 ,s ! /orage batt]y s]v$ z little z compress$ air to solve ! eng9e]'s problem4 ,:5 ! electric dynamo became a comm]cial success = su* purposes z ! op]ation ( trolley l9es x seem$ z if ! ,niag>a problem 0 on ! v]ge ( solution4 ,& s1 9 po9t ( fact1 x really 01 ?\gh m "t 0 requir$ = x ?an at fir/ seem$ ne$$4 ,! p[] g5]at$ by ! dynamo c\ld1 inde$1 be transmitt$ along a wire1 b n )\t great loss4 ,sir ,william ,siem5s1 9 #ahgg1 _h po9t$ out 9 connection ) ?is v subject ( ! wa/$ p[] ( ,niag>a1 t a ?\s& horse-p[] might be transmitt$ a di/ance (1 say1 ?irty miles ov] a copp] rod ?ree in*es 9 diamet]4 ,b a copp] rod ?ree in*es 9 diamet] is enorm\sly exp5sive1 & :5 ,siem5s fur!r /at$ t sixty p] c5t ( ! p[] involv$ w\ld be lo/ 9 transmission1 x 0 obvi\s t ! me?od 0 f> too wa/eful to be comm]cially practicable4 ,= a "t ! exp]im5t]s ) ! transmission ( electricity along a wire 7 on ! wrong track4 ,!y 7 exp]im5t+ ) a cont9u\s curr5t :i*1 z we h se51 is produc$ f an ord9>y dynamo ) ! aid ( a commutator4 ,b ho/s ( exp]im5ts f9ally made x cle> t ?is =m ( curr5t1 no matt] h[ p[]ful x might be1 is unable to trav]se consid]able di/ance )\t great loss1 be+ fritt]$ away 9 ! =m ( heat4 ,b ! v t]m cont9u\s curr5t implies ! exi/5ce ( a curr5t t is n cont9u\s4 ,9 po9t ( fact1 we h already se5 t a dynamo1 if n suppli$ ) a commutator1 w produce :at is call$ an alt]nat+ curr5t1 & su* a curr5t has long be5 kn[n to possess prop]ties peculi> to itself4 ,x is1 9 effect1 an int]rupt$ curr5t1 & x is sometimes spok5 ( z if x really consi/$ ( an alt]nation ( curr5ts :i* move fir/ 9 "o direction & !n 9 ano!r4 ,su* a conception is n really ju/ifiable4 ,! m plausible explanation is t ! alt]nat+ curr5t is "o 9 :i* ! electrons are n ev5ly di/ribut$ & move ) irregul> motion4 ,p]haps we may ?9k ( ! individual electrons ( su* a curr5t z oscillat+ 9 _! flight1 &1 z x 71 bor+ _! way into ! resi/+ m$ium4 ,9 any ev5t1 exp]i5ce %[s t su* a curr5t1 "u prop] conditions1 may be able to trav]se a conduct+ wire = a long di/ance ) relatively small loss4 ,x mu/ be und]/ood1 h[ev]1 t ! m]e fact t a curr5t alt]nates is n 9 itself suffici5t to make feasible its transmission to a remote di/ance4 ,to meet all ! requirem5ts a curr5t mu/ be ( v high voltage4 ,?is means1 9 s f> z we c repres5t ! conditions ( "o =m ( en]gy 9 ! t]ms ( ano!r1 t x %all be "u high pressure4 ,=tunately a relatively simple app>atus enables ! electrician to trans=m a curr5t f l[ to high voltage )\t difficulty4 ,& s at la/ ! problem ( transmitt+ p[] to a di/ance ( _m miles has be5 solv$4 ,electrical curr5ts repres5t+ ?\s&s ( horse-p[] are to-day transmitt$ f ,niag>a ,falls to ! city ( ,buffalo ov] ord9>y wires1 ) a loss t is relatively insignificant4 ,a plant is 9 process ( con/ruction t w simil>ly transmit ! p[] to ,toronto2 & x is pr$ict$ t 9 ! ne> future ! p[]s ( ,niag>a w be drawn ^u by ! factories ( cities ev5 z f> di/ant z ,new ,york & ,*icago4 ,practical difficulties /ill /& 9 ! way ( su* v di/ant transmission1 to be sure1 b ^! are matt]s ( detail1 & are almo/ c]ta9 to be ov]come 9 ! ne> future4 ,all ?is be+ expla9$1 x w be und]/ood t ! sole reason :y ! new p[]-h\ses at ,niag>a g5]ate electricity is t electricity is ! "o readily transportable c>ri] ( en]gy4 ,we h already expla9$ t !re is loss ( en]gy :5 ! /eam eng9e op]ates ! dynamo4 ,at ,niag>a1 ( c\rse1 no /eam is involv$2 x is ! en]gy ( fall+ wat] t is trans=m$ into ! en]gy ( ! electrical curr5t4 ,moreov]1 ! revolv+ dynamo is atta*$ to ! same %aft ) ! turb9e wat]-:eel1 s t !re is no loss ?r\gh ! int]position ( ge>+4 ,yet ev5 s1 ! electric curr5t t fl[s f ! dynamo repres5ts some:at less ( en]gy ?an ! wat] curr5t t fl[s into ! turb9e4 ,?is loss1 h[ev]1 is comp5sat$ a ?\s&fold by ! fact t ! en]gy ( ! electric curr5t may n[ be di/ribut$ 9 ob$i5ce to man's w4 ,,/ep ,,up ,,& ,,/ep ,,d[n ,,trans=m]s ,! dynamos 9 op]ation at ,niag>a d n diff] 9 pr9ciple f ^? 9 ! /reet-c> p[]-h\se1 except 9 ! fact t !y are n suppli$ ) commutators4 ,we h se5 t ^! dynamos are ( enorm\s size4 ,^? already 9 op]ation g5]ate five ?\s& horse-p[]2 o!rs 9 process ( con/ruction w develop t5 ?\s&4 ,! g5]ator :i* produces ?is enorm\s curr5t is ab\t elev5 feet 9 diamet]1 & x makes two hundr$ & fifty revolutions p] m9ute4 ,! armatures are s w\nd t ! result is an alt]nat+ curr5t ( electricity ( tw5ty-two hundr$ volts4 ,?is curr5t repres5ts1 x has be5 said1 raw mat]ial :i* is to be v>i\sly trans=m$ z x is suppli$ to diff]5t uses4 ,to factories ne> at h&1 inde$1 ! curr5t ( tw5ty-two hundr$ volts is suppli$ un*ang$2 b = m di/ant consumption x is rais$ to t5 ?\s& volts2 & t portion :i* is s5t away to ! factories ( ,buffalo & o!r equally di/ant places is rais$ to tw5ty-two ?\s& volts4 ,illu/ration3 ,,electrical ,,trans=m]s4 ,! upp] figure %[s ,f]ranti's exp]im5tal trans=m] built 9 #ahhh4 ,x has a clos$ iron circuit1 built up ( ?9 /rips fill+ ! int]ior ( ! coil & hav+ _! ends b5t ov] & ov]lapp+ outside4 ,! l[] figure %[s a simple trans=m] kn[n z ,/urgeon's induction coil4 ,! middle figure gives a view ( ! s]ies ( conv]t]s 9 ! p[] h\se ( ! ,manhattan ,elevat$ ,railway4 ,! trans=mation f a relatively l[ voltage to ! high "o is effect$ by means ( :at is call$ a /ep-up trans=m]4 ,?is is an app>atus :i* br+s into play a pr9ciple ( electric induction n v diff]5t f t :i* 0 responsible = ! g5]ation ( ! curr5t ( electricity 9 ! dynamo4 ,! pr9ciple is t evid5c$ 9 ! famili> laboratory app>atus kn[n z ! ,ruhmkorff coil4 ,! trans=m] consi/s ess5tially ( a prim>y coil ( relatively l>ge wire1 surr\nd$ by1 b insulat$ f1 a second>y coil ( relatively f9e wire4 ,:5 ! int]rupt$ curr5t is s5t ?r\gh ! prim>y coil ( su* an app>atus1 an induc$ c\nt]-curr5t is g5]at$ 9 ! second>y coil4 ,( c\rse !re is no ga9 9 ! actual quantity ( electricity1 b ! voltage ( ! curr5t g5]at$ 9 ! f9] wire is greatly increas$4 ,= example1 z we h se51 ! curr5t t came f ! dynamo at tw5ty-two hundr$ volts is rais$ to t5 ?\s& or tw5ty-two ?\s& volts4 ,^! proportions may be v>i$ indef9itely by v>y+ ! relative sizes & l5g?s ( ! prim>y & second>y coils4 ,h[ %all we picture to ourselves ! actual *ange 9 ! curr5t repres5t$ by ?is diff]5ce 9 voltage8 ,we might prove1 readily en\gh1 t ! diff]5ce is a real "o1 s9ce a wire c>ry+ a curr5t ( l[ voltage may be h&l$ ) impunity1 :ile a simil> wire c>ry+ a curr5t ( high voltage may n safely be t\*$4 ,b :5 we attempt to visualize ! diff]5ce 9 ! two curr5ts we are all at sea4 ,we may suppose1 ( c\rse1 t electrons spread out ov] a long /ret* ( ! second>y coil mu/ be m widely scatt]$4 ,"o c conceive t ! electrons1 ?us relatively unimp$$1 may acquire a mom5tum1 & h5ce a p5etrative p[]1 :i* !y reta9 aft] !y are cr[d$ toge!r 9 a /raight conductor4 ,b ?is sugge/ion at be/ m]ely haz>ds a guess4 ,arriv$ at ! o!r end ( its j\rney1 ! curr5t :i* travels "u ?is high voltage is retrans=m$ into a l[-voltage curr5t by means ( an app>atus :i* simply rev]ses ! conditions ( ! /ep-up trans=m]1 & :i*1 !re=e1 is call$ a /ep-d[n trans=m]4 ,! electricity :i* came to ,buffalo z a tw5ty-two-?\s&-volt curr5t is ?us r$uc$ by any desir$ am\nt be=e x is appli$ to ! practical purposes = :i* x is design$4 ,x may1 = example1 be /epp$-d[n to two ?\s& volts to supply ! ma9 wires ( an electric-light+ plant2 & !n aga9 /epp$-d[n to two hundr$ volts to supply ! electric lamps ( an individual h\se4 ,:o t reads by ! light ( "o ( ^! electric lamps1 let u say 9 ,buffalo1 & realizes t he is read+ by ! trans=m$ en]gy ( ,niag>a ,riv]1 d>e affirm t 9 our day !re is no?+ new "u ! sun8 ,,xi ,,! ,,bani%m5t ,,( ,,night ,"o great fundam5tal advantage t man has won ov] ! o!r animals is t al?\gh by nature a diurnal animal he has made night almo/ equally subject to 8 dom9ion ?r\gh ! use ( artificial light4 ,he ?us e/abli%es an av]age day ( sixte5 or eighte5 h\rs 9 place ( ! twelve-h\r day )9 :i* 8 activities w\ld o!rwise be re/rict$4 ,( c\rse ?is conque/ ( ! night began at an e>ly /age ( ! human developm5t1 s9ce a c]ta9 famili>ity ) ! uses ( fire 0 atta9$ long be=e man came out ( ! ages ( savag]y4 ,b :5 ! transition _h be5 made f ! primitive tor* to ! simple/ type ( lamp1 !re 0 = _m c5turies a cessation ( progress 9 ?is direction1 & x rema9$ = comp>atively rec5t g5]ations to provide m effici5t me?ods ( light+4 ,inde$1 ! culm9at+ a*ievem5ts are matt]s :i* make ! mo/ rec5t hi/ory4 ,x is ! purpose ( ! ensu+ pages to n>rate ! /ory ( ! successive practical a*ievem5ts ?r\gh :i* man has be5 enabl$ virtually to turn night into day4 ,,primitive ,,tor* ,,& ,,op5 ,,lamp ,to mod]ns1 9 an age :5 ev5 ! "t-honor$ gas jets & k]os5e lamps are reg>d$ z obsolesc5t1 t anci5t =m ( illum9ant1 ! c&le1 seems ab\t ! mo/ primitive =m ( light-produc+ app>atus4 ,9 po9t ( fact1 h[ev]1 ! c&le holds no su* place 9 ! *ronological ord] ( light+-device discov]y1 be+ a relatively late innovation4 ,inde$1 lamps ( v>i\s k9ds1 ev5 ^? burn+ petroleum1 7 us$ ?\s&s ( ye>s be=e ! relatively clean & effective c&le 0 inv5t$4 ,! camp fires ( primitive man mu/ h sugge/$ ! use ( a fire-br& = light+ purposes almo/ z soon z ! discov]y ( fire itself2 b ! developm5t ( any means ( light+ 8 caves or rude huts1 ev5 9 ! =m ( tor*es1 0 probably a sl[ process4 ,= our e>lie/ ance/ors 7 n ! nocturnal creatures _! desc5dants became e>ly 9 ! hi/ory ( civilization4 ,to !m ! p]iod ( d>kness 0 ! "t = sleep+1 & _! wak+ h\rs 7 ^? betwe5 dawn & dusk4 ,x 0 only :5 man _h rea*$ a relatively high plane above ! o!r memb]s ( ! animal k+dom1 !re=e1 t he w\ld wi% to prolong ! daylight1 & !n ! use ( ! tor* made ( "s res9\s wood w\ld naturally sugge/ itself4 ,j :5 ! anci5t lamp 0 inv5t$ 9 ! =m ( a vessel fill$ ) oil into :i* "s k9d ( wick 0 dipp$1 _c be asc]ta9$1 b its inv5tion c]ta9ly ant$at$ ! ,*ri/ian ,era by sev]al c5turies4 ,& x is equally c]ta9 t once ?is smoky1 f\l-smell+ lamp _h be5 discov]$1 x rema9$ 9 use1 practically )\t *ange or improvem5t1 until ! end ( ! twelf? c5tury1 ! date ( ! inv5tion ( ! c&le4 ,su* lamps 7 us$ by ! ,greeks & ,romans1 great quantities ( !m be+ /ill pres]v$4 ,!y 7 simply %all[1 sauc]-l vessels = hold+ ! oil1 into :i* ! wick 0 laid1 s arrang$ t ! upp] end re/$ aga9/ ! edge ( ! vessel4 ,"h ! oil burn$ & smok$1 capill>ity supply+ oil to ! burn+ end ( ! wick1 :i* 0 pull$ up f "t to "t z x became %ort5$ by burn+1 ei!r ) p9c]s made = ! purpose1 or p]haps m frequ5tly by ! ev] useful hairp9 ( ! matron4 ,z ! ?ick wick did n all[ ! air to p5etrate to burn ! c>bon ( ! oil completely1 a nause\s smoke 0 giv5 (f con/antly :i* 0 /ifl+ :5 a draught ( air prev5t$ its escape ?r\gh ! hole 9 ! ro(--! only *imney us$ by ! ,greeks4 ,& s9ce ?is 0 ! only k9d ( lamp kn[n at ! "t1 ! palace ( ! ,roman ,emp]or & hut ( ! ,roman peasant 7 necess>ily alike 9 _! me?ods ( light+ if 9 little else4 ,! ,emp]or's lamps might be model$ ( gold & set ) preci\s /ones1 :ile ^? ( ! peasant 7 ( rudely model$ clay2 b ea* mu/ h evok$1 along ) its dim light1 an un:olesome modicum ( smoke & malodor4 ,x 0 ?is =m ( lamp1 practically unalt]$ except occasionally 9 design1 t rema9$ 9 common use dur+ ! ,middle ,ages2 & :51 at ! close ( ! twelf? c5tury1 ! tall[ c&le 0 inv5t$1 t n[ despis$ device mu/ h be5 almo/ z revolution>y 9 its effect z ! inc&esc5t burn] & ! electric bulb 7 de/9$ to be 9 a m rec5t g5]ation4 ,x burn$ ) dazzl+ brilliancy 9 comp>ison ) ! oil lamp2 x gave (f no smoke & little smell2 x ne$$ no c>e1 & x occupi$ little space4 ,!n = ! fir/ "t 9 ! hi/ory ( ! _w reasonably good h\se illum9ation became possible4 ,sev]al additional c5turies elaps$1 h[ev]1 be=e ! idea 0 develop$ ( plac+ a c&le 9 a cov]$ glass-sid$ receptacle1 to =m a lant]n or a /reet lamp4 ,= g5]ations ! c&le held supreme place1 ?\gh its co/ made x some?+ ( a luxury2 d\bly s if wax 0 sub/itut$ = tall[ 9 its composition4 ,b t[>d ! close ( ! eighte5? c5tury1 :5 ! action ( combu/ion _h begun to be bett] und]/ood1 attempts 7 made to improve ! wicks & burn]s ( oil lamps4 ,9 #aghc1 an inv5tor nam$ ,leg]1 ( ,p>is1 produc$ a burn] us+ a broad1 flat1 ribbonlike wick 9 :i* practically e "p ( ! oil supply 0 br\ght into contact ) ! air1 produc+1 !re=e1 a /eady flame relatively free f smoke4 ,! flame1 :ile broad1 0 extremely ?91 & its light 0 consequ5tly radiat$ v unev5ly4 ,portions ( a room ly+ 9 ! direction ( ! long axis ( ! flame 7 b poorly light$4 ,to ov]come ?is difficulty1 a curv$ =m ( burn] 0 adopt$2 & ?is l$ ev5tually to ! inv5tion ( ! circul> ,arg& burn]1 ! prototype ( ! be/ mod]n lamp-burn]s4 ,,tall[ ,,c&le ,,& ,,p]fect$ ,,oil ,,lamp ,/at$ 9 sci5tific t]ms1 ! problem ( ! ideal lamp-wick resolves itself into a "q ( h[ to supply oxyg5 to e portion ( ! flame 9 suffici5t quantities to br+ all ! c>bon p>ticles to a temp]ature at :i* !y are lum9\s4 ,x occurr$ to ,arg& t ?is c\ld be done by giv+ ! wick a circul> =m l a cyl9drical tube1 giv+ ! air free access to ! c5tre ( ! tube z well z to its out] surface4 ,9 8 lamp ! res]voir ( oil 0 plac$ at a little di/ance f1 & slightly above1 ! tube hold+ ! burn]1 connect$ ) x by a small tube mu* z ! tank ( ! mod]n /ud5t lamp connects ) ! burn]4 ,9 ?is mann] a fairly good lamp 0 produc$1--a decid$ improvem5t ov] any made h]et(ore1--& :51 9 #agfe1 ,qu9quet add$ a glass *imney to ?is lamp a new epo* ( artificial light+ 0 inaugurat$4 ,?is date is ( z mu* importance 9 artificial light+ z is #aghi 9 politics1 says "o writ]4 ,betwe5 ! anci5t lamps & ! lamps ( ,qu9quet !re is z mu* diff]5ce z betwe5 ! *imney-place ( our p>lors & ! fireplaces ( our orig9al ,aryan ance/ors1 =m$ by a hole dug 9 ! gr\nd 9 ! c5tre ( _! cab9s4 ,a little lat] ,c>cel /ill fur!r improv$ ! ,qu9quet lamp by adapt+ a clock movem5t t =c$ ! oil to rise to ! wick1 s t x 0 no long] necess>y to h ! burn] & ! res]voir sep>at$ by a tube4 ,?is 0 /ill fur!r improv$ ^u by sub/itut+ a spr+ = ! clockwork1 ! result be+ a lamp ( great simplicity1 yet "o :i* gave su* results t x replac$ ! c&le z a unit = measur+ ! illum9at+ p[] ( diff]5t s\rces ( light4 ,^! v>i\s burn]s %\ld n be confus$ ) ! mod]n burn]s ( ! ord9>y k]os5e lamps4 ,m9]al oils _h n z yet come into use = illum9at+ purposes1 except z tor*es or 9 simple lamps l ^? ( ! ,romans1 z ref9+ processes _h n be5 p]fect$1 & ! smoke & odors f crude petroleum 7 absolutely intol]able 9 clos$ rooms4 ,_m o!r sub/ances 7 tri$ 9 place ( ! heavy oils1 su* z ! volatile hydroc>bons & alcohols1 b ) no great success4 ,e>ly 9 ! n9ete5? c5tury a lamp burn+ turp5t9e1 "u ! "n ( camph9e1 0 inv5t$ t gave a good light & 0 smokeless2 b l mo/ o!rs ( its type1 x 0 dang]\s ow+ to its liability to explode4 ,& x 0 n until me?ods ( ref9+ petroleum _h be5 improv$ t m9]al-oil lamps--! pr$ecessors ( ! mod]n type ( lamps--came into use4 ,! inv5tion ( ?is type ( lamp 0 a relatively easy task--a simple transition & adaptation z processes ( ref9+ ! oil 7 p]fect$4 ,! pr9ciple ( combu/ion 01 ( c\rse1 ! same z 9 ! ,arg& type ( lamps burn+ animal & vegetable oils2 b m9]al oils are ( su* consi/5cy t capill>ity causes an abundant supply ( oil to rise 9 ! wick1 s t clockwork & spr+ devices1 su* z 7 us$ 9 ! ,c>cel lamps1 c\ld be disp5s$ )4 ,,gas ,,light+ ,:ile ! rivalry betwe5 ! c&le & ! new =ms ( lamps 0 at its height1 & j z ! lamp 0 ga9+ complete supremacy1 a new me?od ( artificial illum9ation 0 discov]$ t 0 de/9$ to eclipse all o!rs = half a c5tury1 & !n f9ally to succumb to a /ill bett] =m4 ,z e>ly z ! beg9n+ ( ! eighte5? c5tury ! ,rev4 ,joseph ,clayton1 9 ,engl&1 _h made exp]im5ts 9 ! di/illation ( coal1 produc+ a gas t 0 inflammable4 ,a little lat] ,dr4 ,/eph5 ,hales publi%$ 8 "w on ,vegetable ,/aticks1 9 :i* he describ$ ! process ( di/ill+ coal 9 :i* a def9ite am\nt ( gas c\ld be obta9$ f a giv5 quantity ( coal4 ,no practical use 0 made ( ?is discov]y1 h[ev]1 until ov] half a c5tury lat]4 ,b j at ! close ( ! c5tury a ,scot1 ,william ,murdo*1 became int]e/$ 9 ! possibilities ( gases z illum9ants1 & f9ally demon/rat$ t coal gas c\ld be put to practical use4 ,9 #agih1 be+ employ$ 9 ! work%ops ( ,b\lton & ,watt 9 ,birm+ham1 he fitt$ up an app>atus 9 :i* he manufactur$ gas1 light+ ! work%ops by means ( jets connect$ by tubes ) ?is primitive plant4 ,%ortly aft] ?is1 a ,fr5*man1 ,m4 ,lebon1 light$ 8 h\se 9 ,p>is ) gas di/ill$ f wood1 & ! ,p>isians soon became int]e/$ 9 ! new illum9ant4 ,engl& seems to h be5 ! fir/ c\ntry to use x ext5sively 9 public build+s1 h[ev]1 ! ,london ,lyceum ,!atre be+ light$ ) gas 9 #ahjc4 ,by #ahaj ! great ,gas-,light & ,coke ,company 0 =m$1 & )9 ! next five ye>s gas /reet-lamps _h become famili> objects 9 ! /reets ( ,london1 & h\se illum9ation by ?is means a common ?+ among ! weal?i] classes4 ,9 ! e>ly days ( gas-light+ ! results 7 frequ5tly disappo9t+1 because no suitable & effici5t type ( burn] _h be5 devis$2 b 9 #ahbj ,neilson ( ,glasg[ discov]$ ! pr9ciple ( ! n[ famili> flat burn]1 ( :i* m examples /ill rema9 9 use ! _w ov] ?an ( all o!r k9ds comb9$4 ,inde$1 ?is simple1 b z we n[ reg>d x1 ineffici5t burn]1 w\ld probably h rema9$ ! be/-kn[n type = _m ye>s long] ?an x did _h n ! possibilities ( light+ by electricity ar\s$ p]sons int]e/$ 9 ! great gas-plants to ! fact t ! new illum9ant 0 jeop>diz+ _! enorm\s inve/m5ts2 mak+ x cle> t !y mu/ be/ir !mselves & improve _! flat burn]s if !y w\ld arre/ disa/]4 ,to be sure1 sev]al modifications ( ! r\nd ,arg& burn] _h be5 introduc$ f "t to "t1 "s ( !m be+ a di/9ct improvem5t ov] ! flat burn]1 b ^! did n by any means s]i\sly compete ) electric light4 ,& x 0 n until ! inc&esc5t mantle 0 p]fect$ t gas z a brilliant illum9ant 0 able to make a /& aga9/ its new competitor4 ,,! ,,inc&esc5t ,,gas ,,mantle ,x has be5 kn[n almo/ s9ce ! beg9n+s ( civilization t all solids c be made to emit light :5 heat$ to c]ta9 temp]atures4 ,"s sub/ances 7 kn[n to be peculi>ly adapt$ to ?is purpose1 su* z lumps ( lime1 & = _m ye>s ! calcium light or lime-light z x is popul>ly call$1 _h be5 9 use = special purposes1 & 0 ! mo/ int5se light kn[n4 ,?is light is made by heat+ a block ( lime to ! highe/ practicable temp]ature by means ( a bla/ ( oxyg5 & coal gas2 b su* lights 7 too complicat$ & exp5sive = g5]al purposes4 ,x _h be5 det]m9$ ev5 z e>ly z ! beg9n+ ( ! n9ete5? c5tury1 h[ev]1 t ! high temp]ature necess>y = produc+ ?is light 0 due 9 "p at lea/ to ! fact t su* a l>ge am\nt ( mat]ial _h to be rais$ to inc&esc5ce4 ,x 0 evid5t1 !re=e1 t if a small am\nt ( "s su* sub/ance z lime & magnesia c\ld be spread out s z to pres5t a l>ge surface 9 a small space1 su* z is repres5t$ by basket-"w1 suffici5t heat = mak+ x inc&esc5t might be obta9$ f an ord9>y gas-&-air bl[pipe4 ,"h !n 0 ! g]m ( ! mantle idea2 & su* an app>atus1 kn[n z ! ,clamond mantle1 :i* 0 made ( ?reads ( calc9$ magnesia1 0 %[n at ! ,cry/al ,palace ,exhibition1 9 ,london1 9 #ahhb4 ,curi\sly en\gh1 ?is mantle & burn] work$ 9 an inv]t$ position1 ! mantle be+ susp5d$ bottom upw>ds bel[ ! burn] ?r\gh :i* ! bla/ ( gas 0 =c$4 ,! light giv5 by ?is mantle 0 mo/ brilliant--little %ort ( ! old] calcium light1 9 fact--b ! device itself 0 too complicat$ to be ( s]vice = ord9>y light+ purposes4 ,! pr9ciple 0 correct1 b ! con/ruction ( ! mantle 0 defective4 ,mean:ile a ,g]man sci5ti/1 ,dr4 ,au] von ,welsba*1 :o _h become fam\s 9 ! sci5tific _w = 8 rese>*es on r>e metals1 0 exp]im5t+ ) c]ta9 oxides ( diff]5t metals1 & develop+ a me?od ( h&l+ !m t f9ally result$ 9 ! p]fect$ inc&esc5t burn] 9 use at pres5t4 ,8 process1 :i* 9 !ory at lea/ 0 n entirely orig9al ) him1 0 to dip an op5 fabric ( cotton into a solution ( ! nitrates ( ! metals to be us$1 dry+ x1 & conv]t+ ! nitrates into oxides by burn+2 ! cotton fabric disappe>+ b leav+ ! skeleton ( ! oxide1 :i* reta9$ its orig9al %ape4 ,at ! same "t correspond+ improvem5ts 7 made 9 ! type ( burn]1 :i* is q z ess5tial to success z ! mantle itself4 ,x _h be5 f\nd t x 0 absolutely ess5tial = su* a burn] to give a practically non-lum9\s flame1 z o!rwise ! deposit ( c>bon p>ticles w ru9 ! mantle4 ,two ways ( obta9+ ?is are possible2 "o by mix+ a c]ta9 quantity ( air ) ! gas be=e combu/ion1 ! o!r to burn ! gas 9 s ?9 a flame t ! air p]meates x freely4 ,sev]al burn]s ( bo? types 7 us$ at fir/1 b gradually ! burn]s 9 :i* ! air is mix$ ) ! gas became ! m popul>1 & mo/ ( ! inc&esc5t burn]s n[ on ! m>ket are ( ?is type4 ,9 ! con/ruction ( mantles at ! pres5t "t1 :ile ! pr9ciple ( _! use rema9s ! same z t ( ! lime-light1 lime itself is n us$1 ! oxides ( c]ta9 o!r metals hav+ prov$ bett] adapt$ = ! purpose4 ,?us ! ,welsba* pat5t ( #ahhf cov]$ ! use ( ?oria1 ei!r alone or mix$ ) o!r sub/ances su* z zirconia1 alum9a1 magnesia1 etc42 ?oria be+ consid]$ z hav+ a v high p[] ( light emission4 ,lat] x 0 discov]$ t pure ?oria emits v little light by itself1 al?\gh x possesses a refractory nature t gives a /ability to ! mantle unequall$ by any o!r mat]ial z yet discov]$4 ,:5 comb9$ ) a small trace ( ! oxides ( c]ta9 r>e metals1 h[ev]1 su* z uranium1 t]bium1 or c]ium1 ?oria mantles h a v high p[] ( light emission1 mo/ mod]n mantles be+ compos$ ( ab\t n9ety-n9e p] c5t4 ?oria ) "o p] c5t4 c]ium4 ,9 ! ord9>y me?od ( manufactur+ su* mantles1 a cotton-net cyl9d] ab\t eight in*es long1 m or less accord+ to ! size ( mantle requir$1 is made1 "o end be+ contract$ by an asbe/os ?read4 ,a loop ( ! same mat]ial1 or 9 "s cases a plat9um wire1 is fa/5$ across ! op5+1 to be us$ = susp5d+ ! mantle :5 9 use4 ,! cotton-?read cyl9d] is soak$ 9 a solution ( ! nitrates ( ! metals ?orium & c]ium1 & is !n wrung out to remove ! excess1 /ret*$ on a conical mold1 & dri$4 ,! flame ( an atmosph]ic burn] be+ appli$ to ! upp] "p at ! con/rict$ position1 ! burn+ ext5ds d[nw>d1 conv]t+ ! nitrates into oxides1 & remov+ ! organic matt]4 ,consid]able skill is requir$ 9 ?is "p ( ! process1 z ! regul> %ape ( ! mantle is l>gely dep5d5t ^u ! regul>ity ( ! burn+4 ,z a f9i%+ process a flame is appli$ to ! inside ( ! mantle aft] x has cool$1 to remove all traces ( c>bon t may rema94 ,! mantle is n[ ready = use1 b is s fragile t x c sc>cely be t\*$ )\t break+1 & su* h&l+ z w\ld be necess>y = %ipm5t w\ld be out ( ! "q4 ,x is !re=e /r5g!n$ tempor>ily by be+ dipp$ into a mixture ( collodion & ca/or oil1 :i*1 :5 dry1 =ms a firm b ela/ic jacket surr\nd+ all p>ts4 ,x is ?is collodion jacket t is burn$ away :5 ! new mantle is plac$ on ! burn] be=e ! gas is turn$ on4 ,q rec5tly ! me?od ( manufactur+ mantles us$ by ,clamond has be5 reviv$4 ,9 ?is me?od ! cotton ?read is disp5s$ )1 ! ?read us$ be+ made f a pa/e conta9+ ! mantle mat]ial itself4 ,! pa/e is plac$ 9 a prop] receptacle ! bottom ( :i* is p]=at$ ) m9ute op5+s1 & subject$ to pressure1 squeez+ out ! mat]ial 9 long filam5ts4 ,:5 dry ^! are w\nd on bobb9s1 &1 aft] be+ treat$ by c]ta9 *emical processes1 are ready = weav+ into mantles4 ,x is claim$ = mantles made on ?is pr9ciple t !y la/ mu* long] & reta9 _! light-emitt+ p[] m uni=mly ?an mantles made by ! old] process4 ,,! ,,introduction ,,( ,,acetyl5e ,,gas ,:5 ! inc&esc5t mantle _h be5 p]fect$ s z to be an economical z well an z effici5t light-giv]1 ! position ( coal gas z an illum9ant seem$ aga9 secur$ aga9/ ! encroa*m5ts ( its rivals1 ! arc & inc&esc5t electric lights4 ,b j at ?is "t ano!r rival appe>$ 9 ! field t n only m5ac$ ! mantle lamp b ! arc & inc&esc5t light z well4 ,curi\sly en\gh1 ?is new rival1 acetyl5e gas1 _h be5 br\ght into exi/5ce comm]cially by ! electric arc itself4 ,= al?\gh x _h be5 kn[n z a possible illum9ant = _m ye>s1 ! calcium c>bide = produc+ x c\ld n be manufactur$ economically until ! adv5t ( ! electric furnace1 itself ! outcome ( ,davy's arc light4 ,ev5 z e>ly z #ahcf an ,engli% *emi/ _h made ! discov]y t "o ( ! by-products ( ! manufacture ( metallic potassium w\ld decompose wat] & evolve a gas conta9+ acetyl5e2 & ?is 0 lat] obs]v$ indep5d5tly f "t to "t by sev]al *emi/s 9 diff]5t c\ntries4 ,no importance 0 atta*$ to ^! discov]ies1 h[ev]1 & no?+ 0 done ) acetyl5e z an illum9ant until ! la/ decade ( ! n9ete5? c5tury4 ,by ?is "t electric furnaces _h come into g5]al use1 & x 0 :ile work+ ) "o ( ^! furnaces 9 #ahib t ,mr4 ,?omas ,f4 ,wilson1 9 prep>+ metallic calcium f a mixture ( lime & coal1 produc$ a peculi> mass ( d>k-color$ mat]ial1 calcium c>bide1 :i*1 :5 ?r[n into wat]1 evolv$ a gas ) an extremely disagreeable odor4 ,:5 light$1 ?is gas burn$ ) a/oni%+ brilliancy1 &1 z its co/ ( production 0 extremely small1 ! idea ( utiliz+ x = illum9at+ 0 at once conceiv$ & put into practice4 ,! secret ( ! *eap manufacture ( ! c>bide lies 9 ! fact t ! extremely high temp]ature requir$--ab\t #dejj ,fahr5heit--c be obta9$ economically 9 ! electric furnace1 b n o!rwise4 ,?us electricity creat$ its own greate/ rival z an illum9ant4 ,x foll[$ naturally t ! ideal place = manufactur+ ! c>bide w\ld be at ! s\rce ( ! *eape/ supply ( electricity1 & z ! h>ness$ ,niag>a ,falls repres5t$ ! *eape/ s\rce ( electric supply1 ?is place soon became ! c5tre ( ! c>bide indu/ry4 ,"h ! process ( manufacture is c>ri$ out on an enorm\s scale4 ,9 practice1 lime & gr\nd coke are ?or\ghly mix$ 9 ! proportion ( ab\t fifty-six p>ts ( lime to ?irty-six p>ts ( coke4 ,:5 ?is mixture has be5 subject$ to ! heat ( ! electric furnace = a %ort "t an +ot ( pure calcium c>bide is =m$1 surr\nd$ by a cru/ ( less pure mat]ial4 ,! +ot & cru/ toge!r repres5t sixty-f\r p>ts ( ! orig9al n9ety-two p>ts ( lime & coke1 ! rema9+ tw5ty-eight p>ts be+ lib]at$ z c>bon-monoxide gas4 ,calcium c>bide z produc$ by ?is process is a d>k-br[n cry/all9e sub/ance :i* may be heat$ to r$ness )\t dang] or *ange4 ,x w n burn except :5 heat$ 9 oxyg51 & w keep indef9itely if seal$ f ! air4 ,*emically x consi/s ( "o atom ( lime comb9$ ) two atoms ( c>bon 7,ca,c#b72 & to produce acetyl5e gas1 :i* is a comb9ation ( c>bon & hydrog5 7,c#b;,h#b7 x is only necess>y to br+ x into contact ) wat]1 acetyl5e gas & slak$ lime be+ =m$4 ,"o p\nd ( pure c>bide w produce five & "o half cubic feet ( gas ( great] illum9at+ p[] ?an any o!r kn[n gas4 ,! flame is absolutely :ite & ( bl9d+ brilliancy1 giv+ a spectrum closely approximat+ t ( sunlight4 ,! light is s /rongly act9ic t x is excell5t = photography4 ,"h 0 a gas t c\ld be made 9 any desir$ quantities simply by add+ wat] to a sub/ance co/+ only ab\t ?ree c5ts a p\nd2 its co/ ( production1 !re=e1 repres5t+ only ab\t "o six? ( ! doll>-p]-?\s&-feet rate usually *>g$ = illum9at+ gas 9 our cities4 ,x c\ld be us$ 9 lamps & lant]ns made ) special burn]s & ) ! simple me*anism ( a small wat] tank :i* all[$ wat] to drip into a receptacle hold+ ! c>bide2 or--rev]s+ ! process--an app>atus t dropp$ pieces ( c>bide into ! wat] tanks4 ,x 01 9 %ort1 ! *eape/ illum9ant kn[n1 g5]at$ by an app>atus t 0 simplicity itself4 ,!re 71 h[ev]1 two defects 9 ?is gas3 its odor 0 intol]able--! smell ( decay$ g>lic1 x has be5 aptly call$--& :5 mix$ ) air x 0 highly explosive4 ,! fir/ ( ^! defects c\ld be ov]come easily2 :5 ! burn] consum$ all ! gas !re 0 no odor4 ,! second1 ! explosive quality1 pres5t$ great] difficulties4 ,^! 7 emphasiz$ & magnifi$ by ! numb] ( defective lamps t soon flood$ ! m>ket1 _m ( ^! be+ s badly con/ruct$ t explosions 7 inevitable4 ,z a result a /rong prejudice quickly arose aga9/ ! gas1 "s c\ntries pass+ laws prohibit+ its use4 ,b fur!r inquiry into ! cause ( ! frequ5t disa/]s reveal$ ! fact t :5 ! burn] ( a lamp 0 con/ruct$ s t ! air = combu/ion 0 suppli$ aft] ! gas issu$ f ! jet1 !re 0 no dang] ( explosion4 ,& z lamps c>efully con/ruct$ on ?is pr9ciple replac$ ! e>ly ones ( faulty con/ruction1 confid5ce 9 acetyl5e 0 re/or$4 ,me?ods 7 devis$ = supply+ ! gas = h\se-illum9ation l ord9>y gas1 & ! occupants ( c\ntry h\ses 7 af=d$ a means ( light+ _! h\ses on a scale ( brilliancy hi!rto unapproa*$1 yet ) economy & relative safety4 ,x 0 f\nd also t ! brilliancy ( ! acetyl5e flame 0 ( su* int5sity t x c\ld be us$1 l ! electric arc light1 z a se>*-light4 ,x ?us furni%$ a simple means ( supply+ small boats & vehicles ) su* lights1 :i* !y c\ld n o!rwise h _h4 ,x also suppli$ army signal-corps ) an app>atus = fla%+ messages--an app>atus t 0 ideal on acc\nt ( its simplicity & small size4 ,at ! ,pan-,am]ican ,exhibition at ,buffalo ! v>i\s illum9at+ exhibits 7 among ! mo/ conspicu\s & attractive features4 ,b ev5 amid ! dazzl+ electrical displays ! ,acetyl5e ,build+ 0 a notewor?y object4 ,x 0 ! mo/ brilliantly & beautifully light$ build+ 9 ! gr\nds1 decl>$ "o obs]v]4 ,x sp>kl$ l a diamond1 & 0 ! admiration ( all visitors4 ,9 x 7 g5]ators ( all types--mo/ ( !m supply+ ! gas = _! own exhibits--sev]al be+ ! late/ expon5ts ( ! art1 s simple t !y c be safely manag$ by unskill$ labor2 9 fact1 '! bra9s are 9 ! ma*9es1' & :5 ! att5dant has *>g$ !m ) c>bide & fill$ !m ) wat]--giv5 !m food & dr9k--!y w "w /eadily until !y ne$ ano!r meal4 ,inde$1 ^! exhibits at ! ,pan-,am]ican ,exhibition demon/rat$ conclusively t acetyl5e gas occupies a field by itself z a practical illum9ant4 ,at ! same exposition a /&>d 0 e/abli%$ = good /ation>y acetyl5e g5]ators = h\se-light+1 & ! fact t a l>ge numb] ( g5]ators fulfill$ ! requirem5ts ( ! set ( rules laid d[n %[$ h[ ?or\ghly ! problem ( h&l+ ?is gas has be5 solv$4 ,"s ( ^! rules us$ z te/s are in/ructive to anyone int]e/$ 9 ! subject1 & a few ( !m are giv5 "h4 ,!y specifi$1 = example1 t-- ,! c>bide %\ld be dropp$ into ! wat]1 ! rev]se process ( lett+ ! wat] drip on ! c>bide1 z 0 done 9 mo/ ( ! e>ly g5]ators1 be+ condemn$4 ,!re mu/ be no possibility ( mix+ air ) ! acetyl5e gas4 ,con/ruction mu/ be su* t an addition to ! *>ge ( c>bide c be made at any "t )\t affect+ ! lights4 ,g5]ators mu/ be entirely automatic 9 _! action--t is to say3 aft] a g5]ator has be5 *>g$1 x mu/ ne$ no fur!r att5tion until ! c>bide has be5 entirely exhau/$4 ,! v>i\s op]ations ( dis*>g+ ! refuse1 fill+ ) fre% wat]1 *>g+ ) c>bide1 & />t+ ! g5]ator mu/ be s simple t ! g5]ator c be t5d$ by an unskill$ workman )\t dang] ( accid5t4 ,:5 ! lights are out1 ! g5]ation ( gas %\ld cease4 ,! c>bide %\ld be f$ automatically into ! wat] 9 proportion to ! gas consum$4 ,p]haps ! mo/ significant ?+1 %[+ ! /age ( progress t has be5 made 9 ov]com+ ! dang] ( explosions f acetyl5e gas1 is t ! use ( g5]ators meet+ "s su* requirem5ts z ! above is n prohibit$ by fire und]writ]s4 ,?is 9 itself is v conv9c+ evid5ce ( _! safety4 ,,! ,,triumph ,,( ,,electricity ,?r\gh\t ! ages primitive man _h _h con/antly be=e him two s\rces ( light o!r ?an t ( ! sun1 moon1 & />s4 ,"o ( ^!1 ! fire ( ord9>y combu/ion1 he c\ld und]/& & utilize2 ! o!r1 m p[]ful & m t]rible1 :i* fla%$ across ! heav5s at times1 he c\ld n ev5 vaguely und]/&1 &1 naturally1 did n attempt to utilize4 ,b e>ly 9 ! sev5te5? c5tury "s sci5tific discov]ies 7 made :i*1 al?\gh _! de/9ation 0 n ev5 imag9$ at ! "t1 po9t$ ! way t ev5tually l$ to man's imitat+ 9 ! mo/ /rik+ mann] ,nature's electrical illum9ation4 ,ab\t ?is "t ,otto von ,gu]icke1 ! burgoma/]-philosoph] ( ,magdeburg1 9 ! c\rse ( 8 num]\s exp]im5ts1 _h discov]$ "s ( ! prop]ties ( electricity1 by rubb+ a sulphur ball1 & among o!r ?+s _h notic$ t :5 ! ball 0 rubb$ 9 a d>k5$ room1 a fa9t gl[ ( light 0 produc$4 ,he 0 aw>e1 also1 t 9 "s way ?is 0 connect$ ) ! g5]ation ( electricity1 b 9 :at mann] he _h no conception4 ,9 ! op5+ ye>s ( ! foll[+ c5tury ,francis ,hauksbee obta9$ some:at simil> results ) glass globes & tubes1 & made sev]al important discov]ies z to ! prop]ties ( electricity t /imulat$ an int]e/ 9 ! subject among ! philosoph]s ( ! "t4 ,gray 9 ,engl&1 & ,dufay 9 ,france1 :o became en?usia/ic work]s 9 ! field1 soon e/abli%$ important facts reg>d+ conduction & insulation1 & by ! middle ( ! eighte5? c5tury ! production ( an electric sp>k _h become a commonplace demon/ration4 ,b until ?is "t x _h n be5 demon/rat$ t ?is electric sp>k 0 actual fire1 al?\gh !re 0 no disput+ ! fact t x produc$ light4 ,9 #agdd1 h[ev]1 ?is po9t 0 settl$ def9itely by ! ,g]man1 ,*ri/ian ,fri$ri* ,ludolff1 :o project$ a sp>k f a rubb$ glass rod ^u ! surface ( a b[l ( e!r1 caus+ ! liquid to bur/ into flame4 ,a few ye>s lat] ,b5jam9 ,frankl9 demon/rat$ ) 8 kite & key t lightn+ is a manife/ation ( electricity4 ,b nei!r ! galvanic cell nor ! dynamo _h be5 inv5t$ at t "t1 & !re 0 no possibility ( produc+ any?+ l a su/a9$ artificial light ) ! /atic electrical ma*9es !n 9 use4 ,x 0 n until ! classic discov]y ( ,galvani & ! result+ inv5tion ( ! voltaic1 or galvanic1 cell %ortly aft]1 t ! electric light1 9 ! s5se ( a su/a9$ light1 became possible4 ,& ev5 !n1 z we %all see 9 a mom5t1 su* a light 0 too exp5sive to be ( any use comm]cially4 ,,davy ,,& ,,! ,,fir/ ,,electric ,,light ,z soon z ,volta's great inv5tion 0 made kn[n a new wave ( en?usiasm 9 ! field ( electricity swept ov] ! _w1 = ! con/ant & relatively tractable curr5t ( ! galvanic batt]y sugge/$ possibilities n conceivable ) ! old] friction ma*9es4 ,batt]ies conta9+ l>ge numb]s ( cells 7 devis$2 "o hav+ two ?\s& su* elem5ts be+ con/ruct$ = ,sir ,humphry ,davy at ! ,royal ,in/itution1 ( ,london4 ,by br++ two po9ts ( c>bon1 repres5t+ ! two poles ( ! batt]y1 close toge!r1 ,davy caus$ a jet ( flame to play betwe5 !m--n a mom5t>y sp>k1 b a cont9u\s light--a true voltaic arc1 l t se5 9 ! mod]n /reet-light to-day4 ,:5 pieces ( *>coal ab\t an in* long & "o-six? ( an in* 9 diamet] 7 br\ght ne> ea* o!r 7)9 ! ?irtie? or =tie? ( an in*71 wrote ,davy 9 describ+ ?is exp]im5t1 a bright sp>k 0 produc$1 & m ?an half ! volume ( *>coal became ignit$ to :it5ess2 &1 by )draw+ ! po9ts f ea* o!r1 a con/ant dis*>ge took place ?r\gh ! heat$ air1 9 a space equal to at lea/ f\r in*es1 produc+ a mo/ brilliant asc5d+ ar* ( light1 broad & conical 9 =m 9 ! middle4 ,:5 any sub/ance 0 introduc$ into ?is ar*1 x in/antly became ignit$2 plat9a melt$ 9 x z readily z wax 9 a common c&le2 qu>tz1 ! sapphire1 magnesia1 lime1 all ent]$ into fusion2 fragm5ts ( diamond & po9ts ( *>coal & plumbago seem$ to evaporate 9 x1 ev5 :5 ! connection 0 made 9 ! receiv] ( an air-pump2 b !re 0 no evid5ce ( _! hav+ previ\sly und]gone fusion4 ,:5 ! communication betwe5 ! po9ts positively & negatively electrifi$ 0 made 9 ! air r>efi$ 9 ! receiv] ( ! air-pump1 ! di/ance at :i* ! dis*>ge took place increas$ z ! exhau/ion 0 made2 & :5 ! atmosph]e 9 ! vessel support$ only "o-f\r? ( an in* ( m]cury 9 ! b>ometrical gauge1 ! sp>ks pass$ ?r\gh a space ( ne>ly half an in*2 &1 by )draw+ ! po9ts f ea* o!r1 ! dis*>ge 0 made ?r\gh six or sev5 in*es1 produc+ a mo/ brilliant coruscation ( purple light2 ! *>coal became int5sely ignit$1 & "s plat9a wire atta*$ to x fus$ ) brilliant sc9tillations & fell 9 l>ge globules ^u ! plate ( ! pump4 ,all ! ph5om5a ( *emical decomposition 7 produc$ ) int5se rapidity by ?is comb9ation4 ,x w be se5 f ?is t z f> z ! actual light+-"p ( ,davy's app>atus 0 conc]n$1 x 0 completely successful4 ,b ! s\rce ( ! curr5t--! mo/ ess5tial "p ( ! app>atus--0 su* t ev5 ! weal?y c\ld h>dly af=d to indulge 9 x z a luxury4 ,! initial co/ ( two ?\s& cells 0 only a small item ( exp5se comp>$ ) ! co/ ( ma9ta9+ !m 9 work+ ord]1 & pay+ skill$ op]ators to c>e = !m4 ,s t = ! mom5t no practical results came f ?is demon/ration1 conclusive ?\gh x 01 & ! introduction ( a comm]cial electric light 0 ( necessity def]r$ until a *eap] me?od ( g5]at+ electricity %\ld be discov]$4 ,?is discov]y 0 n made = ano!r g5]ation1 b !n1 z seems entirely fitt+1 x 0 made by ,davy's successor & =m] assi/ant at ! ,royal ,in/itution1 ,sir ,mi*ael ,f>aday4 ,8 discov]y ( electromagnetic induction 9 #ahca = ! fir/ "t made possible ! electric dynamo1 al?\gh /ill ano!r g5]ation pass$ be=e ?is inv5tion took practical =m4 ,9 ! meantime1 h[ev]1 ! magneto-electric ma*9e ( ,nollet 0 us$ = g5]at+ an electric curr5t = illum9at+ purposes z e>ly z #ahfc2 & :5 f9ally ! dynamo-electric ma*9e 0 produc$ by ,gramme 9 #ahgj1 eng9e]s & inv5tors _h at _! disposal ev]y?+ necess>y = produc+ a practical electric illum9ant4 ,x mu/ n be suppos$1 h[ev]1 t inv5tors /ood by pati5tly ) fold$ h&s wait+ = ! com+ ( a ma*9e t w\ld furni% !m ) an adequate curr5t )\t attempt+ to produce electric lamps4 ,on ! contr>y1 !y 7 con/antly wre/l+ ) ! problem1 9 "s in/ances be+ fairly successful1 ev5 be=e ! inv5tion ( ! magneto-electric ma*9e4 ,great advances _h be5 made 9 batt]ies & cell con/ruction ov] ! primitive cells ( ! "t ( ,davy1 & = exhibition purposes1 & ev5 = light+ factories & l>ge build+s1 fairly good electric lights _h be5 us$ be=e #ahfc4 ,! fir/ practical application ( electric light+ seems to h be5 made 9 ,france 9 #ahdi4 ,dur+ ! production ( ! op]a ,! ,prophet ! sun 0 to appe>1 & = ?is purpose an electric arc light 0 us$4 ,! success ( ?is ef=t--an artificial sun be+ produc$ t seem$ almo/ z dazzl+ to ! a/oni%$ audi5ce z ,old ,sol himself--/imulat$ fur!r ef=ts 9 ! same direction4 ,! previ\s ye> ,w4 ,e4 ,/aite 9 ,engl& made exp]im5ts along simil> l9es 9 ! l>ge hall ( ! hotel ( ,sund]l&4 ,he g5]at$ a light resembl+ ! sun1 or ! light ( day1 & mak+ c&les appe> z obscure z !y d by daylight1 accord+ to ! ,times ( ! foll[+ morn+4 ,! electric light 0 !re=e prov$ to be a practical illum9ator1 al?\gh x 0 n until ! introduction ( ! ,gramme dynamo-electric ma*9e t its great economic utility 0 demon/rat$4 ,,! ,,jablo*k(f ,,c&le ,9 ,sir ,humphry ,davy's exp]im5ts ) 8 arc light he 0 l$ to believe t ! light betwe5 ! two po9ts ( c>bon w\ld be produc$ ev5 9 an absolute vacuum1 if x 7 possible to create "o4 ,sev]al sci5ti/s at ! "t disput$ ?is cont5tion1 & ,m4 ,masson1 ,pr(essor ( ,physics 9 ! cole ,c5trale des ,arts et ,manufactures 9 ,p>is 0 p>ticul>ly active 9 combatt+ ! idea1 ma9ta9+ t ! arc _h ! same cause z ! electric sp>k--! transport by electricity ( ! inc&esc5t p>ticles ( ! electrodes ?r\gh ! atmosph]e4 ,x 0 c]ta91 at any rate1 t no light 0 produc$ :5 ! oppos+ c>bons 7 br\ght into contact ) ea* o!r1 or 71 on ! o!r h&1 sep>at$ too widely2 & s9ce !re 0 a con/ant we>+ away & %ort5+ ( ! po9ts1 & ?us a con/antly increas+ space betwe5 !m1 ! great difficulty 9 mak+ a practical lamp lay 9 regulat+ ?is di/ance automatically4 ,x 0 f9ally accompli%$1 h[ev]1 by ! inv5tion ( a ,russian (fic]1 ,m4 ,jablo*k(f1 9 #ahgf4 ,! ,jablo*k(f c&le1 z 8 lamp 0 call$1 m>k$ an epo* 9 ! hi/ory ( electric light+4 ,"o great m]it ( ?is inv5tion 0 its simplicity1 & :ile x has long s9ce gone out ( use1 hav+ be5 sup]s$$ by /ill simpl] & bett] devices1 x mu/ always be recall$ z an important /epp+-/one 9 ! progress ( artificial illum9ation4 ,! "n c&le = ,jablo*k(f's lamp 0 sugge/$ by ! fact t ! two c>bons 7 plac$ side by side1 in/ead ( po9t to po9t1 ! light at ! top ?us sugge/+ a c&le4 ,betwe5 ^! two c>bons1 & ext5d+ _! :ole l5g? except at ! v tips1 0 an insulat+ mat]ial t ! arc c\ld n pi]ce1 b :i* burn$ away at a rate comm5surate ) ! %ort5+ ( ! c>bons4 ,9 ?is mann] ! po9ts 7 kept con/antly at ! prop] di/ance )\t regulat+-ma*9]y ( any k9d4 ,?is +5i\s app>atus _h ! additional advantage t x c\ld be plac$ on any k9d ( a bracket or *&eli] t 0 prop]ly wir$1 ?us disp5s+ ) ! cumb]some frames & ma*9es ( ! po9t-to-po9t c>bon arc lights !n be+ introduc$4 ,"o difficulty at fir/ enc\nt]$ 9 us+ ! ,jablo*k(f c&le 0 ! />t+ ( ! voltaic arc4 ,9 do+ ?is x 0 necess>y t contact be made betwe5 two c>bon po9ts1 :e!r !y lie p>allel or po9t to po9t1 & ! necess>y slight sep>ation = produc+ ! light effect$ lat]4 ,to accompli% ?is ,jablo*k(f jo9$ ! tips ( ! c>bons ( 8 c&le ) a ?9 /rip ( c>bon1 :i* quickly burn$ away :5 ! curr5t 0 turn$ on1 leav+ ! necess>y space betwe5 ! po9ts = ! arc4 ,!re 0 "o difficulty ) ! c&le t seem$ insurm\ntable = a "t--! wa/+ ( ! two c>bons 0 unequal1 z 9 any arc light1 ! po9ts ?us gradually draw+ ap>t until ! passage ( ! curr5t 0 no long] possible4 ,to ov]come ?is ! rapidly wa/+ positive c>bon 0 made d\ble ! ?ickness ( its mate2 b :ile ?is answ]$ fairly well ! ?9n] negative c>bon gradually became heat$ by ! increas$ resi/ance1 & burn$ up too rapidly4 ,! difficulty 0 f9ally ov]come by ! simple exp$i5t ( alt]nat+ ! fl[ ( ! curr5t1 s t ea* c>bon 0 alt]nately a positive & a negative pole4 ,z ! magneto-electric ma*9es !n 9 use produc$ alt]nat+ curr5ts x 0 only necess>y to use su* ma*9es = g5]at+ ! curr5t to produce an equal de/ruction ( bo? c>bons4 ,! simplicity & excell5ce ( ! light ( ^! c&les br\ght !m at once into g5]al popul>ity1 n only 9 ! l>ge cities ( ,europe1 b 9 _m out-(-!-way places4 ,greece1 ,portugal1 & o!r obscure ,european c\ntries adopt$ !m1 & ev5 ,brazil1 ,la ,plata1 & ,mexico in/all$ _m plants4 ,b /rang] /ill1 !y 7 soon us$ = illum9at+ ! palaces ( ! ,%ah ( ,p]sia & ! ,k+ ( ,cambodia1 & a little lat] 7 introduc$ into ! resid5ce ( ! savage ,k+ ( ,burma4 ,9 %ort1 _! use became univ]sal almo/ imm$iately4 ,,! ,,improv$ ,,arc ,,light ,ab\t ! "t t ,jablo*k(f's c&les 7 mak+ su* a s5sation 9 ,europe1 ,*>les ,f4 ,bru%1 ( ,clevel&1 ,ohio1 inv5t$ an arc light 9 :i* ! c>bons 7 set po9t to po9t1 ! di/ance be+ ma9ta9$ & ! necess>y fe$ produc$ automatically 9 mu* ! same mann] z 9 ! lamps us$ at pres5t4 ,o!r inv5tions soon foll[$1 "s ( ! lamps be+ regulat$ by clockwork1 "s by electricity & magnetism4 ,! advantage ( ?is type ( arc lamp ov] ! c&le type--an advantage t l$ to its g5]al adoption--0 l>gely t ( effici5cy1 a f> great] am\nt ( light be+ obta9able f ! same exp5diture ( p[] by ! po9t-to-po9t type ( lamp4 ,9 ?is lamp x is necess>y t ! po9ts ( c>bon %all come 9 contact :5 ! curr5t is (f1 b be drawn ap>t a mom5t aft] ! curr5t is turn$ on1 & rema9 at ?is fix$ di/ance4 ,to accompli% ?is1 ! l[] c>bon is usually made /ation>y1 ! fe$+ be+ regulat$ by ! position ( ! upp] c>bon4 ,9 ! usual type ( mod]n lamp ! passage ( ! curr5t causes ! po9ts to sep>ate ! requir$ di/ance ?r\gh ! action ( an electromagnet ! coils ( :i* are trav]s$ by ! curr5t4 ,a clut* holds ! c>bon 9 place1 ! position ( ?is be+ also det]m9$ by an electromagnet4 ,! action is regulat$ by ! diff]5ce 9 ! resi/ance to ! passage ( ! curr5t caus$ by ! increase 9 ! sep>ation ( ! po9ts4 ,9 ! old] type ( arc lamp x 0 necess>y to trim ! lights by replac+ ! c>bons e day2 b rec5tly lamps h be5 p]fect$ 9 :i* ! c>bons la/ f "o hundr$ to "o hundr$ & tw5ty h\rs4 ,9 ^! ! arc is enclos$ 9 a glass globe :i* is made z ne>ly air-tight z possible ) ! necess>y fe$ devices4 ,?is clos$ *amb] is fitt$ ) a valve op5+ outw>d1 :i* all[s ! air to be =c$ out by ! heat ( ! lamp1 b does n admit a return curr5t4 ,9 ?is mann] a r>efi$ *amb] is produc$ 9 :i* ! c>bons are oxidiz$ v sl[ly2 yet !re is no dim9ution 9 ! brilliancy ( ! light4 ,e>ly 9 ! hi/ory ( electric light+ x became app>5t t ! prop] con/ruction ( ! c>bon electrodes 0 a highly important item 9 ! manufacture ( a light+ app>atus4 ,! value ( c>bons dep5ds l>gely ^u _! purity & fre$om f a% 9 burn+1 & x requir$ a c\ntless numb] ( exp]im5ts to develop ! highly effici5t c>bons n[ 9 g5]al use4 ,davy made use ( pieces ( wood *>coal 9 8 exp]im5ts1 b ^! 7 too fragile to be ( practical value1 ev5 if _! o!r qualities _h be5 ideal4 ,lat] exp]im5t]s tri$ v>i\s comp\nds1 & 9 #ahgf ,c>r 9 ,france produc$ excell5t c>bons made ( coke1 lampblack1 & syrup4 ,f ^! 7 develop$ ! pres5t c>bons1 usually made by mix+ "s f9ely divid$ =m ( c>bon1 su* z soot or lampblack made f burn+ p>aff9 or t>1 ) gum or syrup to =m a pa/e4 ,rods ( prop] size & %ape are made by =c+ ?is pa/e ?r\gh dies by hydraulic pressure1 subsequ5tly bak+ !m at a high temp]ature4 ,sometimes !y are giv5 a coat+ ( copp]1 a ?9 lay] ( ! metal be+ deposit$ ^u !m by electrolysis4 ,,edison ,,& ,,! ,,inc&esc5t ,,lamp ,! famili> inc&esc5t electric-light bulb seems su* a simple app>atus to-day1 be+ no?+ app>5tly b a small wire enclos$ 9 an ord9>y glass bulb1 t x is almo/ impossible to realize :at an enorm\s am\nt ( money1 en]gy1 & t p>ticul> quality ( m5tality :i* we call g5ius has be5 requir$ to produce x4 ,fir/ & =emo/ among ! names ( ! m5 ( g5ius :o f9ally evolv$ ?is lamp is t ( ,?omas ,a4 ,edison2 & only second to ?is =emo/ "n are ^? ( ,swan1 ,lane-,fox1 & ,hiram ,maxim4 ,b ,edison's "n mu/ /& preem95t2 & !re are probably v few1 ev5 among ,europeans1 :o w\ld attempt or wi% to d5y him ! enviable place z ! actual p]fect] ( ! inc&esc5t-light bulb4 ,illu/ration3 ,,?omas ,a4 ,,edison ,,& ,,! ,,dynamo ,,t ,,g5]at$ ,,! ,,fir/ ,,comm]cial ,,electric ,,light4 ,x is said t ,edison fir/ conceiv$ ! idea ( an inc&esc5t electric light :ile on a trip to ! ,rocky ,m\nta9s 9 company ) ,drap]1 9 #ahgh4 ,be ?is z x may1 he c]ta9ly set to "w imm$iately aft] complet+ ?is j\rney1 & nev] relax$ or ceas$ 8 ef=ts until a practical inc&esc5t lamp _h be5 produc$4 ,8 idea 0 to p]fect a lamp t w\ld d ev]y?+ t gas c\ld d1 & m2 a lamp t w\ld give a cle>1 /eady light1 )\t odor1 or excessive heat su* z 0 giv5 by ! arc lights--9 %ort1 a h\sehold lamp4 ,e>ly 9 8 exp]im5ts he ab&on$ ! voltaic arc1 decid+ t a successful lamp mu/ be "o 9 :i* inc&esc5ce is produc$ by a /rong curr5t 9 a conductor1 ! heat caus$ by ! resi/ance to ! curr5t produc+ ! gl[ & light4 ,b :5 se>* 0 made = a suitable sub/ance possess+ ! necess>y prop]ties to be ! inc&esc5t mat]ial1 ! inv5tor 0 confront$ by a va/ array ( difficulties4 ,x 0 ( c\rse ess5tial t ! sub/ance mu/ rema9 inc&esc5t )\t burn+1 & at ! same "t (f] a resi/ance to ! passage ( ! curr5t precisely su* z w\ld br+ ab\t ! heat+ t produc$ inc&esc5ce4 ,x %\ld be infusible ev5 "u ?is high degree ( heat1 or o!rwise x w\ld soon disappe>2 & x mu/ n be readily oxidizable1 or x w\ld be de/roy$ z by ord9>y combu/ion4 ,x %\ld also be ( mat]ial r$ucible to a filam5t z f9e z hair1 b capable ( pres]v+ a rigid =m4 ,^!1 among o!rs1 7 ! qualities to be consid]$ 9 select+ ?is app>5tly simple filam5t = ! inc&esc5t lamp4 ,x 0 n a task = ! tyro1 !re=e1 t ,edison und]took :5 he began 8 exp]im5ts = produc+ an ideal lamp4 ,! sub/ance 9 nature t seem$ to possess mo/ ( ! necess>y qualities j enum]at$ 0 ! metal plat9um1 & ,edison began at once exp]im5t+ ) ?is4 ,he made a small spiral ( v f9e plat9um wire1 :i* he enclos$ 9 a glass globe ab\t ! size ( an ord9>y baseball4 ,! two ends ( ! wires connect$ ) outside conduct+ wires1 :i* 7 seal$ into ! base ( ! bulb4 ,! air 9 ! bulb _h to be exhau/$ & a vacuum ma9ta9$ to dim9i% ! loss ( heat & ( electricity & to prev5t ! oxidation ( ! plat9um4 ,b :5 ! curr5t 0 pass$ ?r\gh ! spiral wire 9 ?is vacuum a peculi> *ange took place 9 ! plat9um itself4 ,! gases reta9$ 9 ! pores ( ! metal at once escap$1 & ! wire took on su* peculi> physical prop]ties t x 0 suppos$ = a "t by "s physici/s t a new metal _h be5 produc$4 ,! metal acquir$ a v high degree ( ela/icity & became susceptible ( a high poli% l silv]1 at ! same "t becom+ almo/ z h>d z /eel4 ,x also acquir$ a great] calorific capacity s t x c\ld be made mu* m lum9\s )\t fus+4 ,to dim9i% ! loss ( heat ! wire 0 coat$ ) "s metallic oxide1 & ! slope ( ! spiral also aid$ 9 ?is z ea* turn ( ! spiral radiat$ heat ^u its neighbor1 ?us utiliz+ a c]ta9 am\nt t w\ld o!rwise h be5 lo/4 ,b despite all ?is1 ,edison f\nd1 aft] t$i\s exp]im5t+1 t plat9um did n fulfil ! requirem5ts ( a practical filam5t = 8 lamp2 x ei!r melt$ or dis9tegrat$ 9 a %ort "t & became useless2 & ! o!r exp]im5t]s _h met ) ! same ob/acles to its use1 & 7 =c$ to ! same conclusion4 ,"s o!r sub/ance mu/ be f\nd4 ,! use ( c>bon = arc lights & ,edison's own exp]im5ts ) c>bon 9 8 "w on ! telephone naturally sugge/$ ?is sub/ance z a possibility4 ,x is said t ?is idea 0 br\ght =cibly to ! inv5tor's att5tion by notic+ ! delicate spiral ( vegetable c>bon left 9 8 h& aft] us+ a twi/$ bit ( pap]1 "o day1 = light+ a cig>4 ,?is spiral ( c>bon 01 ( c\rse1 too fragile to be ( use 9 its ord9>y =m4 ,b x occurr$ to ,edison t if a means ( consolidat+ x c\ld be f\nd1 !re 0 reason to hope t x w\ld answ] ! purpose4 ,exp]im5ts 7 begun at once1 !re=e1 n only ) processes ( consolidation b also ) v>i\s k9ds ( pap]1 & nei!r ef=t nor exp5se 0 sp>$ to te/ e kn[n v>iety ( pap]4 ,moreov]1 _m new v>ieties ( pap] 7 manufactur$ at great exp5se f sub/ances hav+ peculi> fibres4 ,"o ( ^!1 made f a delicate cotton gr[n on "s little isl&s (f ,s\? ,c>ol9a1 gave a c>bon free f a%1 & seem$ to promise good results2 b lat] x 0 f\nd t ! curr5t ( electricity did n circulate ?r\gh ?is sub/ance ) suffici5t regul>ity to get protract$ & uni=m effects4 ,nev]!less1 s9ce _m ?+s po9t$ to ?is fibre c>bon z ! ideal sub/ance1 ,edison set ab\t det]m9+ ! cause ( ! irregul>ity 9 ! circulation ( ! curr5t 9 ! filam5t1 & a numb] ( o!r exp]im5t]s soon became int]e/$ 9 ! problem4 ,x 0 soon det]m9$ t ! arrangem5t ( ! fibres !mselves 7 directly responsible = ! difficulty4 ,9 ord9>y pap] ! fibres are press$ toge!r )\t any special arrangem5t1 l wool fibres 9 felt+4 ,9 pass+ ?r\gh su* a sub/ance1 !re=e1 ! curr5t _c travel along a cont9u\s fibre1 b mu/ jump f fibre to fibre1 l a man cross+ a brook on /epp+-/ones4 ,ea* piece ( fibre con/itutes a lamp or m9iature voltaic arc1 s t ! curr5t is no long] a cont9u\s "o2 & ! little int]ior sp>ks ?us g5]at$ quickly de/roy ! filam5t4 ,?is discov]y made x app>5t t su* an artificial1 feltlike sub/ance z pap] c\ld n be made to answ] ! purpose1 & ,edison set ab\t se>*+ = "s natural sub/ance hav+ fibres suffici5tly long to give ! necess>y homog5eity = ! passage ( ! curr5t4 ,= ?is purpose specim5s ( all ! woods & fibre-sub/ances ( all c\ntries 7 exam9$4 ,special ag5ts 7 s5t to ,india1 ,*9a1 ,japan1 ,s\? ,am]ica1 9 que/ ( peculi> fibr\s sub/ances4 ,! v>i\s woods ?us secur$ 7 despat*$ to ! ,edison plant at ,m5lo ,p>k & !re c>efully exam9$ & te/$4 ,)\t dwell+ on ! endless details ( ?is t$i\s task1 x may be said at once t only ?ree sub/ances out ( all ! mass )/ood ! te/s reasonably well4 ,( ^!1 a species ( ,japanese bamboo 0 f\nd to answ] ! purpose be/4 ,?us ! practical inc&esc5t lamp1 :i* _h co/ s mu* "t1 +5uity1 & money1 came into exi/5ce1 fulfill+ ! expectation ( ! mo/ sangu9e dream ( its inv5tor4 ,9 us+ ^! bamboo c>bon filam5ts ! orig9al spiral =m ( filam5t 0 ab&on$1 ! n[ famili> elongat$ horse%oe be+ adopt$1 z ! c>bon c\ld n be b5t into ! tortu\s %apes possible ) plat9um4 ,lat] v>i\s modifications 9 ! %ape ( ! filam5t 7 made1 usually z adaptations to *anges 9 ! %ape ( ! bulbs4 ,at ! same "t t ,edison 0 succe$+ ) 8 bamboo c>bon filam5ts1 ,j4 ,w4 ,swan _h be5 almo/ z successful ) a filam5t =m$ by treat+ cotton ?read ) sulphuric acid1 ?us produc+ a p>*m5tiz$ ?read1 :i* 0 aft]w>ds c>boniz$4 ,a modification ( ?is process ev5tually supplant$ ! ,edison bamboo filam5t2 & ! filam5t n[ 9 common use--! successor ( ! p>*m5tiz$ ?read--is made ( a =m ( soluble cellulose prep>$ by dissolv+ purifi$ cotton wool 9 a solution ( z9c *loride1 & !n press+ ! mat]ial out into long ?reads by press+ x ?r\gh a die4 ,! long ?read s obta9$ is a semi-transp>5t sub/ance1 resembl+ catgut1 :i* :5 c>boniz$ at a high temp]ature =ms a v ela/ic =m ( c>bon filam5t4 ,to prep>e ! filam5t ! cellulose ?reads are cut into ! prop] l5g?s1 b5t into horse%oe %ape1 d\ble loops1 or any desir$ =m1 & !n fold$ r\nd c>bon =m]s & imm]s$ 9 plumbago crucibles4 ,on heat+ ^! crucibles to a high temp]ature ! organic matt] ( ! filam5ts is de/roy$1 ! c>bon filam5ts rema9+4 ,^! filam5ts are !n ready = atta*m5t to ! plat9um lead+-9 wires1 :i* is accompli%$ ei!r by means ( a c>bon cem5t or by a c>bon-deposit+ process4 ,!y are !n plac$ 9 ! glass bulbs & ! wires h]metically seal$1 aft] :i* ! bulbs are exhau/$1 te/$1 fitt$ ) ! famili> brass coll>s1 & are ready = use4 ,! comb9$ discov]ies ( all exp]im5t]s _h made x evid5t t c]ta9 conditions 7 necess>y to success1 reg>dless ( ! /ructure ( ! c>bon filam5t4 ,x 0 ess5tial t ! vessel conta9+ ! filam5t %\ld be entirely ( glass2 t ! curr5t %\ld be convey$ 9 & out ?is by means ( plat9um wires h]metically seal$ ?r\gh ! glass2 & t ! glass globe mu/ be z ?or\ghly exhau/$ z possible4 ,?is la/ requirem5t prov$ a difficult "o = a "t1 b by improv$ me?ods x f9ally became possible to produce almo/ a p]fect vacuum 9 ! bulbs1 ) a correspond+ increase 9 ! effici5cy ( ! lamps4 ,,! ,,tung/5 ,,lamp ,= tw5ty ye>s ! c>bon-filam5t lamp /ood )\t a rival4 ,b mean:ile ! sci5ce ( *emi/ry 0 mak+ rapid /rides & putt+ at ! disposal ( practical inv5tors _m sub/ances hi!rto unkn[n1 or n available 9 comm]cial quantities4 ,among ^! 7 ?ree metals1 osmium1 tantalum1 & tung/51 & ^! metals soon m5ac$ ! app>5tly secure position ( ! highly satisfactory1 al?\gh exp5sive1 ,edison lamp4 ,x w be recall$ t ! e>ly exp]im5t]s _h us$ two metals1 plat9um & iridium1 = lamp filam5ts2 & t ^! two1 al?\gh unsatisfactory1 7 ! only ones t _h giv5 ev5 a promise ( success4 ,b 9 #ahih ,dr4 ,au] von ,welsba* took out pat5ts1 & 9 #aijc produc$ a lamp us+ an osmium filam5t4 ,its adv5t m>k$ ! beg9n+ ( ! return to metal-filam5t lamps1 al?\gh ! lamp itself did n prove to be v satisfactory & 0 quickly displac$ by a lamp inv5t$ by ,messrs4 ,siem5s & ,halske1 hav+ a tantalum filam5t4 ,on acc\nt ( its ease to manufacture1 its brilliant light1 & relatively l[ consumption ( p[]1 ?is lamp ga9$ great popul>ity at once1 & = a s+le ye> 0 practically )\t a rival4 ,!n1 9 #aijd1 pat5ts 7 tak5 out by ,j & ,hanaman1 ,kuzel1 & ,welsba*1 = lamps us+ filam5ts ( tung/51 & ! sup]iority ( ^! lamps ov] ! tantalum lamps gave !m an imm$iate popul>ity nev] atta9$ by ei!r ( ! o!r metal-filam5t lamps4 ,ne$less to say !re is good gr\nd = ?is popul>ity1 :i* may be expla9$ by ! simple /atem5t t ! tung/5 lamp gives m light ) mu* less consumption ( p[] p] c&le p[] ?an any ( its pr$ecessors4 ,unlike ! c>bon filam5t1 :i* projects 9 ! famili> elongat$ horse-%oe loop1 or d\ble loop1 into ! exhau/$ bulb1 ! tung/5 filam5t is w\nd on a frame1 s t sev]al filam5ts 7usually eight or m7 are us$ = produc+ ! light 9 ea* bulb4 ,! *ief defect ( ?is lamp is ! fragility ( ! filam5t1 :i* breaks easily :5 subject$ to me*anical vibration4 ,on ! o!r h&1 tung/5 lamps c be us$ 9 places at a long di/ance f ! c5tral g5]at+ plant1 :]e ! electric curr5t is too weak = c>bon-filam5t lamps4 ,,! ,,m]cury-,,vapor ,,light ,,( ,,pet] ,,coop] ,,hewitt ,on an ev5+ 9 ,janu>y1 #aijb1 a great cr[d 0 attract$ to ! entrance ( ! ,eng9e]s' ,club 9 ,new ,york city4 ,ov] ! doorway a n>r[ glass tube gleam$ ) a /range blue-gre5 light ( su* int5sity t pr9t 0 easily readable across ! /reet1 & yet s s(tly radiant t "o c\ld look directly at x )\t ! s5sation ( bl9d+ discom=t :i* accompanies ne>ly all brilliant artificial lights4 ,! hall )91 :]e ,mr4 ,hewitt 0 mak+ ! fir/ public ann\ncem5t ( 8 great discov]y1 0 also illum9at$ by ! wond]ful new tubes4 ,! light 0 diff]5t f any?+ ev] se5 be=e1 grateful to ! eyes1 mu* l daylight1 only giv+ ! face a curi\s1 pale-gre51 une>?ly appe>ance4 ,! cause ( ?is ph5om5on 0 soon evid5t2 ! tubes 7 se5 to give =? all ! rays except r$1--orange1 yell[1 gre51 blue1 violet1--s t "u its illum9ation ! room & ! /reet )\t1 ! faces ( ! spectators1 ! clo?+ ( ! wom51 lo/ all _! %ades ( r$2 inde$1 *ang+ ! face ( ! _w to a pale gre5-blue4 ,! extraord9>y appe>ance ( ?is lamp & its pr(\nd significance z a sci5tific discov]y at once awak5$ a wide public int]e/1 especially among electricians :o be/ und]/ood its importance4 ,"h 0 an entirely new sort ( electric light4 ,! famili> inc&esc5t lamp1 ?\gh ! be/ ( all me?ods ( illum9ation1 is also ! mo/ exp5sive4 ,mr4 ,hewitt's lamp1 ?\gh n yet adapt$ to all ! purposes s]v$ by ! ,edison lamp1 on acc\nt ( its peculi> color1 produces eight times z mu* light ) ! same am\nt ( p[]4 ,x is also practically inde/ructible1 !re be+ no filam5t to burn out2 & x requires no special wir+4 ,by means ( ?is inv5tion electricity1 in/ead ( be+ ! mo/ co/ly means ( illum9ation becomes ! *eape/--*eap] ev5 ?an k]os5e4 ,no fur!r explanation ?an ?is is necess>y to %[ ! enorm\s importance ( ?is inv5tion4 ,z j /at$1 ! defect ( ! ,edison inc&esc5t lamp is its co/1 due to its utiliz+ only a small fraction ( ! p[] us$ 9 produc+ ! inc&esc5ce1 &1 ( mu* less importance1 ! relatively %ort life ( ! filam5t itself4 ,only ab\t ?ree p] c5t4 ( ! actual p[] is utiliz$ by ! light1 ! rema9+ n9ety-sev5 p] c5t4 be+ absolutely wa/$2 & x 0 ?is enorm\s wa/e ( en]gy t fir/ attract$ ! att5tion ( ,mr4 ,hewitt1 & l$ him to direct 8 en]gies to f9d+ a sub/itute t w\ld be m economical4 ,a l>ge "p ( ! wa/e 9 ! ,edison bulb is kn[n to be due to ! conv]sion ( ! en]gy into useless heat1 in/ead ( light1 z %[n by ! heat$ glass4 ,mr4 ,hewitt attempt$ to produce a light t w\ld use up ! p[] 9 light alone--to produce a cool light1 9 %ort4 ,in/ead ( direct+ 8 ef=ts to ! solids1 ,mr4 ,hewitt turn$ 8 att5tion to gase\s bodies1 believ+ t an inc&esc5t gas w\ld prove ! m ne>ly ideal sub/ance = a cool light4 ,! field ( ! passage ( electricity ?r\gh gases 0 by no means a virg9 "o1 b 0 nev]!less relatively unexplor$3 & ,mr4 ,hewitt 01 !re=e1 = ! mo/ "p oblig$ to dep5d ^u 8 own rese>*es & exp]im5ts4 ,9 ^! exp]im5ts hundr$s ( gases 7 exam9$1 "s ( !m giv+ enc\rag+ results1 b mo/ ( !m pres5t+ insurm\ntable difficulties4 ,f9ally m]cury vapor 0 tri$1 ) ! result t ! light j ref]r$ to 0 produc$4 ,! possibilities ( m]cury-vapor gas _h long be5 vaguely suspect$--suspect$1 9 fact1 s9ce ! e>ly days ( electrical inve/igation1 two c5turies be=e4 ,! ,engli% philosoph]1 ,francis ,hauksbee1 z e>ly z #agje _h %[n t light c\ld be produc$ by pass+ air ?r\gh m]cury 9 an exhau/$ receiv]4 ,he _h discov]$ t :5 a bla/ ( air 0 driv5 up aga9/ ! sides ( ! glass receiv]1 x appe>$ all r\nd l a body ( fire1 consi/+ ( an abundance ( gl[+ globules1 & cont9u+ until ! receiv] 0 ab\t half full ( air4 ,hauksbee call$ ?is 8 m]curial f\nta91 & al?\gh he 0 unable to acc\nt = ! production ( ?is peculi> light1 :i* he rem>k$ resembl$ lightn+1 he attribut$ x to ! action ( electricity4 ,betwe5 ,hauksbee's m]curial f\nta9 & ,hewitt's m]cury-vapor light1 h[ev]1 !re is a wide gap1 &1 z x happ5$1 ?is gap is practically unbridg$ by int]m$iate exp]im5ts1 = ,mr4 ,hewitt _h nev] *anc$ to he> any?+ ( ,hauksbee's e>ly exp]im5ts1 or ( any ( ! t5tative ones ( lat] sci5ti/s4 ,b ?is1 on ! :ole1 may h be5 r advantage\s ?an o!rwise1 z1 be+ ignorant1 he 0 p]haps 9 a m receptive /ate ( m9d ?an if hamp]$ by false or prejudicial conceptions4 ,be ?is z x may1 he began exp]im5t+ ) m]cury conf9$ 9 a glass tube f :i* ! air _h be5 exhau/$1 ! m]cury be+ vaporiz$ ei!r by heat+1 or by a curr5t ( electricity4 ,no results ( any importance came ( 8 num]\s exp]im5ts = a "t1 b at la/ he made ! all-important discov]y t once ! high resi/ance ( ! cold m]cury 0 ov]come1 a comp>atively weak curr5t w\ld !n be conduct$1 produc+ a brilliant light f ! gl[ ( ! m]cury vapor4 ,"h1 !n1 0 ! secret ( ! use ( m]cury vapor = light+--a p[]ful curr5t ( electricity = a fraction ( a second pass$ ?r\gh ! vapor to ov]come ! initial resi/ance1 & !n ! passage ( an ord9>y curr5t to produce ! light4 ,9 practice ?is app>5t difficulty 9 ov]com+ ! initial resi/ance ) a /rong curr5t is easily ov]come by ! use ( a boo/+ coil1 :i* supplies ! /rong curr5t = an in/ant1 & is !n %ut (f automatically1 ! ord9>y curr5t cont9u+ = produc+ ! light4 ,! me*anism is h>dly m complex ?an t ( ! ord9>y inc&esc5t light1 b ! curr5t ( ord9>y /r5g? produces an illum9ation ab\t eight times z int5se z ! ord9>y inc&esc5t bulb ( equal c&le-p[]4 ,! =m ( lamp us$ is t ( a long1 horizontal tube susp5d$ ov]head 9 ! room1 a brilliant light be+ diffus$1 :i*1 lack+ ! r$ rays ( ord9>y lights1 gives a blui%-gre5 tone to objects1 & a p>ticul>ly gha/ly & unpleasant appe>ance to faces & h&s1 z ref]r$ to a mom5t ago4 ,9 _m ways ?is feature ( ! light is really a peculi>ity r ?an a defect1 & = practical purposes 9 "w requir+ cont9u$ eye-/ra9 ! abs5ce ( ! r$ rays is frequ5tly advantage\s4 ,9 su* close "w z t ( p5-draw+1 = example1 "s arti/s f9d x advantage\s to use globes fill$ ) wat] t9t$ a fa9t gre5 color1 plac$ betwe5 ! lamps & _! pap]1 ! effect produc$ be+ some:at ! same z t ( ! m]cury-vapor light4 ,= su* "w ! abs5ce ( ! r$ rays ( ! ,hewitt light w\ld n be consid]$ a defect2 & 9 work%ops & (fices :]e ,mr4 ,hewitt's lamps are us$ ! workm5 h become en?usia/ic ov] !m4 ,on ! o!r h&1 ! fact t ! color-values ( objects are s completely *ang$ makes ?is light objectionable = ord9>y use2 s mu* s1 9 fact1 t ! inv5tor 0 l$ to take up ! problem ( introduc+ r$ rays 9 "s mann] s z to produce a pure :ite light4 ,he has p>tly accompli%$ ?is by means ( p9k clo? color$ ) rhodium ?r[n ar\nd ! glass2 b ?is causes a di/9ct loss ( brilliancy4 ,! mo/ natural me?od ( introduc+ ! r$ rays1 x w\ld seem1 w\ld be to use globes ( r$ glass2 b a mom5t's reflection w %[ t ?is w\ld n solve ! difficulty4 ,r$ glass does n *ange light waves1 b simply suppresses all b ! r$ rays2 & s9ce !re are no r$ rays 9 ! m]cury-vapor light ! result ( ! r$ globe w\ld be to suppress all ! light4 ,obvi\sly1 !re=e1 ?is app>5tly simple me?od does n solve ! difficulty2 b ^? famili> ) ,mr4 ,hewitt's "w w n be surpris$ any day to he> t he has f9ally ov]come all ob/acles1 & produc$ a p]fectly :ite light4 ,9 ! meantime ! relatively exp5sive arc light & ! inc&esc5t bulb ) its filam5t ( c>bon or metal hold un*all5g$ supremacy 9 ! comm]cial field4 ,,xii ,,! ,,m9]al ,,dep?s ,ages be=e ! dawn ( civilization1 primitive man _h le>n$ to extract c]ta9 ores & metals f ! e>? by subt]ranean m9+4 ,su* nations z ! ,egyptians1 = example1 und]/ood m9+ 9 mo/ ( its phases1 & work$ _! m9es 9 practically ! same mann] z all succe$+ nations be=e ! "t ( ! introduction ( ! /eam eng9e4 ,! e>ly ,britons 7 good m9]s & ! products ( _! m9es 7 c>ri$ to ! ,ori5t by ! ,pho5icians _m c5turies be=e ! ,*ri/ian era4 ,! ,romans 71 ( c\rse1 great m9]s1 & rema9s ( ! ,roman m9es are /ill 9 exi/5ce1 p>ticul>ly good examples be+ f\nd 9 ,spa94 ,ev5 ! aborig9es ( ,nor? ,am]ica possess$ "s k ( m9+1 z atte/$ by ! anci5t copp] m9es 9 ! ,lake ,sup]ior region1 al?\gh by ! "t ( ! discov]y ( ,am]ica1 & probably _m c5turies be=e1 ! int]lop+ races ( ,indians :o _h driv5 out or ext]m9at$ ! ,lake ,sup]ior copp] m9es _h =gott5 ! art ( m9+1 if inde$ !y _h ev] le>n$ x4 ,b ! fact t _! pr$ecessors _h work$ ! copp] m9es is %[n by ! numb] ( /one m9+ implem5ts f\nd 9 ! anci5t excavations ab\t ,lake ,sup]ior1 ^! implem5ts be+ f\nd lit]ally by c>t loads 9 "s places4 ,! great progress 9 m9+ me?ods1 h[ev]1 z 9 ! case ( mo/ o!r me*anical arts1 began ) ! introduction ( /eam z a means ( utiliz+ en]gy2 & ano!r revolution is 9 rapid progress ow+ to ! p]fection ( electrical app>atus = furni%+ p[]1 heat1 & light4 ,me?ods ( m9+ a hundr$ ye>s ago 7 und\bt$ly some:at 9 advance ( ! me?ods us$ by ! anci5ts2 b ! gap 0 n a wide "o1 & ! progress made by decades aft] ! introduction ( /eam has be5 inf9itely great] ?an ! progress made by c5turies previ\s to t "t4 ,?is progress1 ( c\rse1 applies to all k9ds ( m9es & all phases ( m9+2 b /eam & electricity are n alone responsible = ! great n9ete5?-c5tury progress4 ,geology1 an unkn[n sci5ce a c5tury ago1 has play$ a mo/ active & important "p2 & *emi/ry1 ^: bir? z a sci5ce dates f ! op5+ ye>s ( ! n9ete5? c5tury1 is responsible = _m ( ! great advances4 ,obvi\sly a v important feature ( any m9e mu/ be its location1 & ! det]m9ation ( ?is mu/ always con/itute ! pr9cipal haz>d 9 practical m9+4 ,prospect+1 or explor+ = suitable m9+ sites1 has be5 an important occupation = _m ye>s1 & has 9 fact become a sci5tific "o rec5tly4 ,=m]ly m9es 7 frequ5tly /umbl$ ^u by accid5t1 b su* accid5tal discov]ies are becom+ less & less frequ5t4 ,! prospector n[ draws l>gely ^u ! k ( ! sci5ti/ to aid him 9 8 se>*4 ,geology1 = example1 assi/s him 9 det]m9+ ! region 9 :i* 8 m9es may be f\nd1 if x _c actually po9t out ! location = s9k+ 8 %aft2 & at lea/ a r\gh k ( botany & *emi/ry is an invaluable aid to him4 ,x is obvi\s t x w\ld be useless to prospect = coal 9 a region :]e no /rata ( rocks =m$ dur+ ! ,c>bonif]\s or coal-=m+ age are to be f\nd )9 a workable di/ance bel[ ! surface ( ! e>?4 ,! prospector mu/1 !re=e1 direct 8 ef=ts )9 geological conf9es if he w\ld hope to be successful1 & 9 ?is he is n[ greatly aid$ by ! geological surveys :i* h be5 made ( almo/ e region 9 ! ,unit$ ,/ates & ,europe4 ,an example ( :at sci5ce has done 9 ?is direction 0 %[n a few ye>s ago 9 a we/]n ,am]ican t[n dur+ "o ( ! oil booms t excit$ s _m communities at t "t4 ,9 ! neighborhood ( ?is t[n evid5ces ( oil _h be5 f\nd f "t to "t--"s ( !m "u peculi> & suspici\s circum/ances1 to be sure--& ! memb]s ( ! community 7 9 an int5se /ate ( excitem5t ov] ! possibility ( oil be+ f\nd on _! l&s4 ,prices ( l& jump$ to fabul\s figures1 & ! few l&-own]s t c\ld be induc$ to "p ) _! f>ms became opul5t by ! transactions4 ,an oil exp]t appe>$ ^u ! sc5e ab\t ?is "t--j happ5+ to drop 9--:o decl>$1 aft] an exam9ation1 t ! entire region ab\nd$ 9 oil4 ,he back$ up 8 ass]tion by (f]+ to /ake 8 exp]i5ce aga9/ ! capital ( a company :i* 0 =m$ at 8 sugge/ion4 ,be=e any wells 7 actually />t$1 h[ev]1 a prud5t memb] ( ! company consult$ ! ,/ate geologi/ on ! subject1 receiv+ ! assurance t no oil w\ld be f\nd 9 ! neighborhood4 ,/rangely en\gh ! ^w ( ! man ( sci5ce triumph$ ov] t ( ! oil exp]t1 & al?\gh "s t5tative bor+s 7 made on a m9or scale1 no great am\nt ( money 0 sunk4 ,x develop$ aft]w>ds t ! evid5ces ( oil f\nd f "t to "t _h be5 ! secret "w ( ! exp]t4 ,9 g5]al1 prospect+ = oil diff]s pretty radically f prospect+ = mo/ o!r m9]als4 ,a v common way ( locat+ an ore-m9e is by ! nature ( ! out-crop1--t is1 ! brok5 edges ( /rata ( rocks protrud+ f hillsides1 or tilt$ at an angle on level areas4 ,if ! ore-be>+ ve9 is h>d] ?an ! surr\nd+ /rata x w be f\nd z a jutt+ edge1 protrud+ beyond ! surface ( ! o!r lay]s ( rocks :i*1 be+ s(t]1 are m easily worn away4 ,on ! o!r h&1 if ?is /ratum is s(t or decomposable x w %[ z a depression1 or sag z x is call$4 ,( c\rse su* protrusions & depressions may only be se5 & exam9$ :]e ! rocks !mselves are expos$2 vegetation1 drift1 & sn[ prev5t+ su* obs]vations4 ,b ! vegetation may 9 itself s]ve z a guide to ! exp]i5c$ prospector 9 det]m9+ ! location ( a m9e1 peculi> m9]al conditions be+ conducive to ! gr[? ( c]ta9 =ms ( vegetation1 or to ! arrangem5t ( su* gr[?4 ,alt]ations 9 ! color ( ! rocks on a hillside are also important guides1 z su* discolorations frequ5tly indicate t oxidizable m9]als are locat$ above4 ,9 hilly or m\nta9\s regions1 :]e ! und]ly+ rocks are cov]$ ) e>?1 portions ( ^! surfaces are sometimes uncov]$ by ! me?od kn[n z boom+4 ,9 us+ ?is me?od ! prospector selects a conv5i5t depression ne> ! top ( a hill & builds a tempor>y dam across ! po9t correspond+ to ! l[e/ outlet4 ,:5 sn[ & ra9 h turn$ ! bas9 s =m$ into a lake1 ! dam is bur/ & ! wat] ru%+ d[n ! hillside cuts away ! ov]ly+ dirt1 expos+ ! rocks b5ea?4 ,?is me?od is effective & inexp5sive4 ,! b$s ( /reams1 p>ticul>ly ^? 9 hilly & m\nta9\s regions1 are f]tile fields = prospect+1 p>ticul>ly = preci\s metals4 ,/ones & pebbles f\nd 9 ! b$ are likely to reveal ! ore-f\ndations along ! c\rse ( ! /ream1 & ! %ape ( ^! pebbles helps 9 det]m9+ ! approximate location ( su* f\ndations4 ,an ore-be>+ pebble1 well worn & r\nd$1 has probably travel$ "s little di/ance f its orig9al s\rce1 be+ r\nd$ & worn 9 its passage d[n ! /ream4 ,on ! o!r h&1 if x is /ill angul> x has come a mu* %ort] di/ance1 & ! prospector w be guid$ accord+ly 9 8 se>* = ! ore-ve94 ,b prospect+ is n limit$ to ^! simple surface me?ods4 ,9 ent]prises und]tak5 on a l>ge scale1 bor+s are frequ5tly made 9 regions :]e !re are p]haps no specific surface indications4 ,9 su* regions a %aft may be sunk or a tunnel may be dug1 & ! condition ( ! und]ly+ /rata ?us def9itely det]m9$4 ,?is la/ is1 ( c\rse1 a mo/ exp5sive me?od1 ! simpl] & m usual way be+ t ( mak+ bor+s to c]ta9 dep?s4 ,! difficulty ) su* bor+s is t ri* ve9s may be pass$ by ! bor] )\t detection2 or1 on ! o!r h&1 a small ve9 happ5+ to lie 9 ! same plane z ! drill may give a wrong impression z to ! ext5t ( ! ve94 ,"o ( ! mo/ satisfactory ways ( mak+ bor+s is by means ( ! diamond drill4 ,?is drill is made 9 ! =m ( a long metal tube1 ! l[] edge ( :i* is made into a cutt+ implem5t by black diamonds fix$ 9 ! edge ( ! metal4 ,by rotat+ ?is tube a r+ is cut ?r\gh ! lay]s ( rock1 ! solid cyl9d] or core ( rock rema9+ 9 ! holl[ c5tre ( ! drill4 ,?is c be remov$ f "t to "t1 ! nature & ?ickness ( ! geological =mation ?r\gh :i* ! drill is pass+ be+ ?us def9itely det]m9$4 ,,conditions ,,to ,,be ,,consid]$ ,,9 ,,m9+ ,?ree great problems always confront ! m9e op]ator--light1 p[]1 & v5tilation4 ,( ^! v5tilation is ! mo/ important f ! workman's /&po9t1 al?\gh ! problem ( light is sc>cely less s4 ,obvi\sly a cavity ( ! e>? :]e hundr$s ( m5 are con/antly consum+ ! atmosph]e & vitiat+ x1 & :]e ?\s&s ( lights are burn+1 w\ld become l ! black hole ( ,calcutta 9 a few m9utes if "s means 7 n adopt$ to relieve ?is condition4 ,b besides ?is vitiation ( ! atmosph]e caus$ by ! respiration ( ! m5 & ! burn+ ( lamps !re are likely to be accumulations ( poison\s gases 9 m9es1 t are ev5 m dang]\s4 ,( ! two classes ( dang]\s gases--^? t asphyxiate & ^? t explode or burn--x may be said 9 a g5]al way t ! suffocat+ or poison\s gases1 su* z c>bonic acid1 :i* is kn[n z black damp1 or *oke damp1 are m likely to occur 9 ore m9es1 :ile ! explosive gases are f\nd m frequ5tly 9 coal m9es4 ,*oke damp1 :i* is a gas consid]ably heavi] ?an ! atmosph]e1 is usually f\nd ne> ! bottom ( m9es1 runn+ along decl9es & fall+ into holes 9 mu* ! same mann] z a liquid4 ,x kills by suffocation1 &1 z x w n support combu/ion1 x may be detect$ by l[]+ a light$ c&le into a suspect$ cavity1 ! light be+ ext+ui%$ at once if ! gas is pres5t4 ,to rid ! cavity ( x1 =c$ v5tilation is us$ :]e possible1 ! gas be+ scatt]$ by draughts ( fre% air4 ,if ?is is impracticable1 & ! cavity small1 ! *oke damp may be dipp$ out ) buckets4 ,b ! problem ( ! m9+ eng9e] is n s mu* to rid cavities ( gas z to prev5t its accumulation4 ,9 mod]n m9+1 ) prop] v5tilation & dra9age1 !re is comp>atively little dang] ( ext5sive accumulation ( ?is gas4 ,illu/ration3 ,a ,,fl9t-,,&-,,/eel ,,outfit1 ,,& ,a ,,m9]',s ,,/eel ,,mill4 ,! upp] picture %[s a fl9t-&-/eel outfit1 ! implem5ts = light+ a fire be=e ! days ( mat*es4 ,! l[] picture %[s a m9]'s /eel mill1 :i* 0 us$ = giv+ light 9 m9es be=e ! day ( ! safety-lamp4 ,x consi/s ( a /eel disk :i* is rotat$ rapidly aga9/ a piece ( fl9t1 produc+ a /ream ( sp>ks4 ,x 0 ?\ght t su* sp>ks w\ld n ignite fire-damp--a belief :i* is n[ kn[n to be errone\s4 ,! dang] f ?is *oke damp1 !re=e1 is "o t conc]ns ! individual workman r ?an l>ge bodies ( m5 or ! /ructure ( ! m9e itself4 ,) fire damp1 h[ev]1 ! case is diff]5t1 z an explosion ( ?is gas may de/roy ! m9e itself & all ! workm5 9 x4 ,x is1 !re=e1 ! mo/ dread$ factor 9 m9+1 & is ! "o to :i* m att5tion has be5 direct$ ?an to almo/ any o!r problem4 ,?is fire damp is a mixture ( c>bonic oxide & m>% gas :i*1 be+ light] ?an air1 t5ds to rise to ! upp] "p ( ! m9es4 ,= ?is reason explosions are m likely to occur ne> ! op5+s ( ! m9e1 frequ5tly entomb+ ! workm5 9 a remote "p ( ! m9e ev5 :5 n actually kill+ !m by ! explosion4 ,z ?is gas is poison\s z well z explosive ! m9]s :o survive ! explosion may succumb ev5tually to suffocation4 ,previ\s to ! ye> #ahaf no means _h be5 devis$ = av]t+ ! explosions ( fire damp except ! unc]ta9 "o ( wat*+ ! flame ( ! c&le ) :i* ! m9] 0 work+4 ,on com+ 9 contact ) air mildly contam9at$ ) fire damp ! c&le flame takes on a blue t9t & assumes a peculi>ly elongat$ %ape :i* may be in/antly detect$ by a wat*ful workman4 ,b m9]s 71 & /ill are1 a prov]bially c>eless class ( m5 ev5 :]e a matt] ( life & dea? is conc]n$1 & too frequ5tly gave no he$ to ! w>n+ flame4 ,b 9 #ahaf ,sir ,humphrey ,davy inv5t$ 8 safety lamp1 a device t has be5 ! means ( sav+ ?\s&s ( lives1 & :i* has n z yet be5 entirely supplant$ by any mod]n inv5tion4 ,9 mak+ 8 num]\s exp]im5ts1 ,davy _h obs]v$ t iron-wire gauze is su* a good conductor ( heat t a flame enclos$ 9 su* gauze c\ld n pass readily ?r\gh me%es to ignite a gas on ! outside4 ,he f\nd by exp]im5t t a consid]able quantity ( explosive gas might be br\ght into contact ) ! gauze surr\nd+ a flame1 & no explosion occur4 ,at ! same "t ?is gas w\ld give w>n+ ( its pres5ce by *ang+ ! color ( ! flame4 ,:5 a lamp 0 made ) a surr\nd+ gauze hav+ sev5 hundr$ & eighty me%es to ! squ>e in*1 x 0 f\nd to give suffici5t light & at ! same "t to be practically non-explosive 9 ! pres5ce ( ord9>y quantities ( gas4 ,"o w\ld suppose t su* a life-sav+ inv5tion w\ld h be5 eag]ly adopt$ by ! m5 ^: lives x protect$2 b1 z a matt] ( fact1 ow+ to c]ta9 inconv5i5ces ( ,davy's lamps1 _m m9]s refus$ to use !m until =c$ to d s by ! m9e-own]s4 ,"o ( ^! disadvantages 0 t ?is safety lamp gave a poor light ov]head4 ,?is is p>ticul>ly annoy+ to ! m9]1 :o wi%es always to wat* ! condition ( ! ceil+ "u :i* he is work+4 ,:5 n "u con/ant obs]vation1 !re=e1 a m9] w\ld frequ5tly remove ! gauze ( ! lamp & "w by ! op5 flame1 reg>dless ( consequ5ces4 ,or aga91 he w\ld sometimes =getfully use ! flame = light+ 8 pipe4 ,to ov]come ! possibility ( su* =getfulness or wilful disob$i5ce1 x 0 f\nd necess>y to equip safety lamps ) lock+ devices1 s t ! m9] _h no means ( access to ! op5 flame ( 8 lamp once x _h be5 light$4 ,s9ce ! "t ( ! fir/ ,davy safety lamp !re h be5 num]\s improvem5ts 9 me*anical details1 al?\gh ! g5]al pr9ciple rema9s un*ang$4 ,"o ( ^! improvem5ts is a device :]eby ! lamp1 :5 accid5tally ext+ui%$1 may be relight$ )\t op5+ x1 & )\t ! use ( mat*es4 ,?is is done by means ( little /rips ( pap] conta9+ pat*es ( a fulm9at+ sub/ance :i* is ignit$ by friction1 work+ on ! same pr9ciple z ! pap] p]cussion caps us$ on toy pi/ols4 ,b ev5 ! improv$ safety lamp seems likely to disappe> f m9es )9 ! next few ye>s1 n[ t electricity has come into su* g5]al use4 ,z yet1 h[ev]1 no satisfactory portable electric lamp or lant]n has be5 p]fect$1 su* lamps be+ z a rule too heavy1 exp5sive1 & unreliable4 ,ev5 if ^! defects 7 rem$i$1 ! advantage w\ld /ill lie ) ! ,davy lamp1 s9ce ! electric lamp1 be+ enclos$1 _c be us$ = ! detection ( fire damp4 ,b ?is advantage ( ! safety lamp is becom+ less important1 s9ce well-regulat$ m9es are n[ m ?or\ghly v5tilat$1 & ! dang] f fire damp correspond+ly less5$4 ,9 "s ,cont95tal m9es ! exp]im5t has be5 tri$ ( con/antly consum+ ! fire damp1 be=e x has _h "t to accumulate 9 explosive quantities1 by means ( num]\s op5 lights kept con/antly burn+4 ,?is me?od is effective1 b s9ce ! num]\s lights consume ! preci\s oxyg5 ( ! air z well z ! damp1 ! me?od has nev] become popul>4 ,obvi\sly1 !n1 ! "q ( m9e v5tilation is closely associat$ ) t ( light+4 ,probably ! simple/ me?od ( prop]ly v5tilat+ a m9e is t ( hav+ two op5+s at ! surface1 "o on a mu* high] level ?an ! o!r if ! m9e is on a hillside1 ! l[] "o correspond+ to ! l[e/ portion ( ! m9e :]e possible4 ,by su* an arrangem5t natural curr5ts w be e/abli%$1 & may be controll$ & di/ribut$ ?r\gh ! m9e by doors or p]man5t p>titions1 or aid$ by fans4 ,b ( c\rse only a comp>atively small numb] ( m9es are s situat$ t ?is sy/em c be us$4 ,x is possible1 ( c\rse1 to v5tilate a m9e f a s+le %aft or op5+ by use ( d\ble sets ( pipes1 "o = admitt+ air & ! o!r = expell+ x2 b ?is sy/em is obvi\sly n an ideal "o1 & is prohibit$ by law 9 mo/ m9+ di/ricts4 ,su* laws usually /ipulate t !re mu/ be at lea/ two op5+s situat$ at "s di/ance f ea* o!r4 ,! old] me?od ( creat+ air curr5ts 0 by means ( furnaces1 b ?is me?od1 :ile v effective1 is exp5sive & dang]\s4 ,9 us+ ?is sy/em a furnace is built ne> ! outlet ( ! air %aft1 ! combu/ion ( ! fuel creat+ ! necess>y draught4 ,b 9 ! nature ( ?+s ?is furnace is a con/ant m5ace to ! m9e1 besides be+ an extremely wa/eful exp5diture ( en]gy4 ,! mod]n me?od ( v5tilat+ is by means ( rot>y fans1 ! electric fan hav+ practically solv$ ! problem4 ,! air curr5ts e/abli%$ by su* fans are controll$ ei!r by ! doors 9 ! passages1 or by means ( auxili>y fans4 ,9 addition1 jets ( compress$ air are sometimes us$1 & h become v popul>4 ,ano!r important problem t con/antly confronts ! m9+ eng9e] is t ( dra9age4 ,m9es are1 ( c\rse1 great res]voirs = ! accumulation ( wat]1 :i* mu/ be dra9$ or pump$ out cont9ually2 & z ! %afts are sunk deep] & deep] x becomes increas+ly difficult to raise ! wat] to ! surface4 ,special means & ma*9]y are employ$ = ?is purpose :i* w be consid]$ m 9 detail 9 a mom5t4 ,,electric ,,ma*9]y ,,9 ,,m9+ ,electricity is1 ( c\rse1 ! great revolution>y factor 9 mod]n m9+4 ,!re is sc>cely a dep>tm5t ( m9+ 9 :i* electric p[] has n wr\ght revolution>y *anges 9 rec5t ye>s2 & ! subject has become s important & s ?or\ghly specializ$ z to create a lit]ature & a te*nology ( its own4 ,f ! electric drill1 work+ hundr$s ( feet bel[ ! surface ( ! e>?1 to ! delicate te/+-in/rum5ts 9 ! laboratory ( ! assay+ (fices1 ! effect ( ?is electrical revolution is be+ felt progressively m & m e ye>4 ,moreov]1 electricity1 on acc\nt ( its transmutability1 has made accessible _m important m9+ sites hi!rto unworkable4 ,ri* m9es are n[ 9 op]ation on an economical basis :i*1 ?irty ye>s ago1 7 wor?less on acc\nt ( _! isolation4 ,:5 su* m9es 7 situat$ 9 m\nta9\s regions :]e !re 0 no coal supply at h& = creat+ /eam p[]1 & :]e ! only available wat] p[] 0 p]haps sev]al miles away1 op]ations on a pay+ basis 7 out ( ! "q be=e ! era ( electric p[]4 ,at pres5t1 h[ev]1 ! "q ( di/ance ( ! seat ( p[] has be5 practically elim9at$ by ! possibilities ( electric conduction4 ,a /ream1 situat$ miles away1 :5 h>ness$ to a turb9e & electric motors may af=d a s\rce ( p[] m economical ?an c\ld be furni%$ a few ye>s ago by a p[] plant suppli$ ) fuel at ! v door ( ! m9e4 ,we ne$ n ent] into ! details ( ?is transmission ( p[]1 h[ev]1 s9ce ! subject has be5 discuss$ 9 a g5]al way 9 ano!r place4 ,our subject "h is r to deal ) ! application ( electricity to c]ta9 m9+ implem5ts ( special importance4 ,"o ( ! mo/ useful acquisitions to ! equipm5t ( ! mod]n m9] is a portable me*anical drill1 :i* makes x possible = him to disp5se ) ! "t-honor$ pick1 hamm]1 & h&-drill4 ,b x is only rec5tly t inv5tors h be5 able to produce ?is implem5t4 ,! great difficulty has la9 9 ! fact t a reciprocat+ motion1 :i* is ess5tial = c]ta9 k9ds ( drill+1 is n readily secur$ ) electric p[]4 ,! use ( /eam or compress$ air = op]at+ su* reciprocat+ drills pres5ts no me*anical difficulties1 & ! fact t p[] ( ?is k9d c be transmitt$ long di/ances by ! use ( flexible tubes made su* drills popul> = sev]al ye>s4 ,b ! co/ ( op]at+ su* drills is s mu* great] ?an t ( ! new electric drills t !y are rapidly be+ replac$ 9 m9+ "w4 ,! fir/ attempts to produce an electric drill ) a reciprocat+ motion 7 s unsuccessful t inv5tors turn$ _! att5tion to p]fect+ "s rot>y device4 ,?is prov$ m successful1 & rot>y drills1 op]at+ long aug]s & act+ l ord9>y wood-bor+ ma*9es1 are n[ us$ ext5sively = c]ta9 k9ds ( drill+4 ,! m rec5t =ms p]=m ! same am\nt ( "w z ! air drill1 ) a consumption ( ab\t "o-t5? ! p[]4 ,moreov]1 none ( ! en]gy is lo/ at high altitudes z 9 ! case ( air drills1 & !y are n affect$ by l[ temp]atures :i* sometimes r5d] ! air drill inop]able4 ,on ! o!r h&1 ! air drill is a h>dy implem5t1 capable ( )/&+ v r\gh usage1 :]eas ! electric drill is probably ! m economical1 z well z ! m conv5i5t drill ( ! two4 ,9 c]ta9 k9ds ( m9+1 su* z 9 ! pota% m9es ( ,europe & ! coal m9es ( ,am]ica1 ^! electric drills op]at+ _! long aug]s h be5 f\nd p>ticul>ly useful4 ,! ord9>y type ( drill is s arrang$ t x c be op]at$ at any angle1 v]tically or horizontally4 ,! light] =ms are m\nt$ on upright /&s1 ) screws at ! ends = fa/5+ to ! floor & ro(1 al?\gh ! heavi] types are sometimes m\nt$ on trucks4 ,! motor1 :i* is n mu* l>g] or heavi] ?an an ord9>y fan motor1 is fa/5$ to ! upright & is f f\r to six horse-p[]4 ,?is connects ) a flexible wire :i* transmits ! p[] f ! g5]at+ /ation1 frequ5tly sev]al miles away4 ,! aug]1 :i* is ab\t ! l>ge/ "p ( ! ma*9e & entirely out ( proportion to ! little motor t drives x1 is simply a long b> ( /eel1 twi/$ spirally at ! cutt+-end l an ord9>y wood aug]4 ,f ! workman's /&po9t ^! rot>y drills are inf9itely sup]ior to reciprocat+ or p]cussion drills1 :]e ! con/ant j>r+ ( ! ma*9e1 besides be+ extremely tiresome1 sometimes produces ! s]i\s disease kn[n z neuritis4 ,v>i\s means h be5 attempt$ to prev5t ?is1 su* z by ov]com+ ! j> 9 a measure by flexible lev]s :i* d n transmit ! vibrations to ! h&s & arms2 b su* attempts are only p>tially successful1 & a c]ta9 am\nt ( j>r+ _c be avoid$4 ,9 ! rot>y electric drills !re is none ( ?is1 ! workm5 simply controll+ ! drill & ! motor ) lev]s1 & receiv+ at mo/ only a slight j> f ! vibrations ( ! aug]4 ,,traction ,,9 ,,m9+ ,9 rec5t ye>s electric traction eng9es = use 9 m9es h be5 rapidly replac+ horse-& mule-p[]1 & h become important economic factors 9 m9+ op]ations4 ,! pione] ( ?is type ( locomotive seems to h be5 "o built by ,mr4 ,w4 ,m4 ,s*less+] = "o ( ! colli]ies ( ! ,p5nsylvania ,railroad ab\t #ahhb1 & :i* has rema9$ 9 active use ev] s9ce4 ,! total weight ( ?is locomotive 0 five tons & x 0 equipp$ ) ?irty-two horse-p[] electric motors4 ,! curr5t 0 suppli$ ?r\gh a trolley pole :i* took ! curr5t f a ,t-%ap$ rail plac$ above & at "o side ( ! track4 ,! tra9 haul$ by ?is locomotive consi/$ ( fifte5 c>s1 c>ry+ f two to ?ree tons ( coal ea*4 ,foll[+ ?is fir/ m9+-locomotive a great numb] 7 quickly produc$4 ,9 ,p5nsylvania alone some?+ l f\r hundr$ are n[ 9 use1 & 9 ,ill9ois two million tons ( coal 7 haul$ 9 ?is mann] 9 twelve m9es 9 #aija4 ,x 0 e/imat$ at ! beg9n+ ( ! pres5t c5tury t "s #c1jjj electric locomotives specially built = m9+ 7 9 use 9 ! ,unit$ ,/ates alone4 ,! e>li] types ( m9+-locomotives 7 mu* high] & bulki] ?an ^? ( m rec5t con/ruction1 ! motors be+ m\nt$ above ! trucks & ge>$ d[nw>d4 ,v soon1 h[ev]1 ! turtle-back or t]rap9-back type 0 develop$1 ) ! motors br\ght close to ! gr\nd1 s t ev5 q a heavy locomotive might n be mu* high] ?an ! diamet] ( its driv+-:eels4 ,:5 ^! que]-look+ ma*9es 7 box$ 9 s t ev5 ! :eels 7 cov]$1 !y lo/ all resemblance to locomotives or vehicles ( any k9d1 appe>+ l l[1 rectangul> metal boxes plac$ ^u ! c> tracks1 t glid$ along ! rails 9 "s my/]i\s mann]4 ,! pres5ce ( ! trolley pole help$ to dispel ?is illusion1 b 9 "s in/ances ?is is want+1 ! p[] be+ tak5 f a ?ird rail4 ,) ^! locomotives1 "s ( !m n m ?an two & a half feet high1 x 0 possible to haul tra9s ev5 9 v l[ & n>r[ passages--mu* l[]1 9 fact1 ?an c\ld be ent]$ by ! little mules us$ 9 =m] ye>s4 ,?is 9 itself 0 revolution>y 9 its effects1 z _m ?9 ve9s 7 ?us made workable4 ,?is type ( l[ locomotive is ! "o t has come into g5]al use ?r\gh\t ! _w4 ,su* locomotives range 9 size f two to tw5ty tons1 ) :eel gauges f a foot & a half wide to ! /&>d railway gauge ( f\r feet1 eight & a half in*es4 ,locomotives weigh+ m ?an tw5ty tons are n 9 g5]al use on acc\nt ( ! small size ( ! m9e entrances4 ,9 ! ord9>y types ! motorman sits 9 front1 controll+ ! locomotive ) lev]s & me*anical brakes plac$ )9 easy rea*1 b sunk z l[ z possible4 ,z a rule1 ! motors are ge>$ to ! truck axles1 ei!r inside or outside ! locomotive frame4 ,an ov]head copp] wire supplies ! curr5t by contact ) a groov$ trolley :eel m\nt$ on ! end ( ! regulation trolley pole4 ,an electric headlight is us$1 & ! ord9>y spe$ atta9$ by ! compact motors is f six to t5 miles an h\r4 ,! am\nt ( "w t c be p]=m$ by "o ( ^! little1 flat1 box-l locomotives is entirely out ( proportion to its size4 ,a #aj-ton locomotive 9 a ,p5nsylvania m9e haul$ ab\t #aej1jjj tons ( coal 9 a ye> at a co/ ( less ?an "o-t5? ( a c5t p] ton = repairs4 ,! usual tra9 0 made up ( ?irty-five c>s1 ea* load$ ) ab\t #c1gjj p\nds ( coal1 :i* 0 haul$ up a ?ree-p]-c5t grade4 ,! co/ ( su* haulage 0 only ab\t #b4gf c5ts p] ton1 z aga9/ #g4ae c5ts :5 haul$ by mule-p[]4 ,^! figures may be consid]$ repres5tative1 z o!r m9es %[ simil> results4 ,illu/ration3 ,,! ,,locomotive ,,puff+ ,,billy ,,& ,a ,,mod]n ,,colli]y ,,trolley4 ,?is locomotive 0 con/ruct$ 9 #ahac at ,wylam ,colli]y1 ,engl&1 by ,william ,h$ley4 ,x 0 entirely successful1 & 0 9 op]ation = almo/ half a c5tury1 up to ! "t ( its removal 9 #ahfb to ! ,s\? ,k5s+ton ,museum4 ,! v]tical cyl9d]s & arrangem5t ( walk+ beams = transmitt+ p[] are p>ticul>ly int]e/+4 ,! p[] 0 transmitt$ ?r\gh cogg$ :eels to ! re> axle1 z is done ) mod]n automobiles4 ,a p>ticul> advantage has be5 ga9$ by ! use ( electric locomotives ov] old] me?ods 9 ! process ( ga!r+ ! c>s4 ,9 _m coal m9es1 ev5 :5 ! ma9 haul+ is done by electricity1 ! ga!r+ or collect+ ( c>s f ! work+ faces ( ! rooms 0 =m]ly done ei!r by mule-p[] or by h&4 ,9 "s l[-ve9$ m9es1 h& p[] alone 0 us$1 on acc\nt ( ! l[ ro(4 ,9 su* places1 l[1 compress$-air locomotives 7 sometimes us$2 b ^! 7 v exp5sive4 ,^! h n[ be5 v g5]ally replac$ by turtle-back electric locomotives1 op]at$ at a di/ance f ! ma9 trolley wire by means ( long1 flexible cables1 s ge>$ t !y c be paid out or coil$ z desir$4 ,on ! ma9 l9e ^! locomotives take ! curr5t f ! trolley wire by means ( ! trolley pole1 b :5 ! place = ga!r+ is rea*$1 ! connection is made by means ( ! flexible cable1 & ! trolley pole fa/5$ d[n s z n to be 9 ! way4 ,?is all[s ! locomotive to pu% ! little c>s into ! rooms f> remov$ f ! ma9 l9e1 ) passages too l[ & n>r[ to all[ ! use ( ! trolley pole4 ,by ! "t ! la/ c>s h be5 deliv]$ ! fir/ c>s ( ! tra9 h be5 fill$1 & ! process ( ga!r+ may be begun at once1 & ! load$ tra9 made up = ! return trip4 ,) su* a locomotive two m5 c di/ribute & ga!r up f "o hundr$ to "o hundr$ & tw5ty c>s 9 an ord9>y eight-h\r work+-day1 haul+ f ?ree hundr$ to ?ree hundr$ & fifty tons ( coal4 ,9 c]ta9 regions1 a sy/em ( ?ird-rail curr5t-supply is us$1 ?is rail be+ also a too? rail ) :i* a cog on ! locomotive works frictionally4 ,= climb+ /eep grades ?is sy/em ( cogg$ rails has _m advantages ov] o!r sy/ems4 ,ano!r type ( electric locomotive us$ 9 "s m9es is a self-propell+ or automobile "o equipp$ ) /orage batt]ies4 ,su* locomotives d away ) ! inconv5i5ce & dang]s ( contact rails or trolley wires1 b are heavy & exp5sive4 ,a compromise locomotive1 p>ticul>ly useful = ga!r+1 is "o equipp$ ) bo? trolley pole & /orage batt]ies4 ,?is locomotive is s made t ! /orage batt]ies are *>g$ :ile x is runn+ ) ! trolley connection1 s t no "t is lo/ 9 ! *>g+ process4 ,su* locomotives h be5 f\nd v satisfactory = _m purposes1 & b = ! imp]fections common to all /orage batt]ies w\ld be ideal 9 _m ways4 ,!y c be work$ ov] any improvis$ track1 reg>dless ( di/ance1 :i* is an advantage ov] ! flexible-cable sy/em :]e di/ances are limit$ by ! l5g? ( cable2 & ! fir/ co/ ( ! batt]y is no m ?an ! outlay on trolley wires & supports4 ,x is also claim$ t ! co/ ( ma9t5ance is relatively l[1 b x is d\btful if x equals ! trolley or ?ird-rail sy/ems 9 ?is respect4 ,closely alli$ to ! sy/ems ( traction by electric locomotives1 is ! mod]n electric telph]age sy/em4 ,until q rec5tly ! haulage ( ores & o!r raw mat]ials us$ 9 m9+1 :5 done a]ially1 has be5 by means ( travell+ rope or cable4 ,:5 di/ances to be travell$ 9 ?is mann] are %ort1 su* z across /reams or valleys1 :]e no supports are us$1 ! t]m cableway is g5]ally appli$2 b :]e ! di/ance is s long t supports are necess>y1 ! t]m tramway cable is us$4 ,x is to ^! long] sy/ems t electric telph]age is p>ticul>ly applicable4 ,! advantage ( su* an electric sy/em ov] ! old] me?od is ! same z ! advantages ( ! trolley road ov] ! cable1 all ropes & cables be+ /ation>y1 ! electric motor1 or telph]1 travell+ along on "o cable & tak+ its curr5t by means ( a trolley pole f a wire above4 ,= heavi] "w metal rails support$ betwe5 po/s are employ$ 9 place ( a flexible cable1 & ov] su* sy/ems loads ( sev]al tons c be haul$4 ,su* an electric telph] sy/em is us$ 9 "o ( ! ,cuban lime/one qu>ries1 ! telph] & c>s travell+ a long di/ance ^u cables1 except at "s ( ! curves1 :]e solid rails are sub/itut$1 haul+ a load ( a ?\s& p\nds at a spe$ ( f twelve to fifte5 miles an h\r4 ,! curr5t comes f a di/ant s\rce1 & ! telph] is s arrang$ t x travels automatically :5 ! curr5t is turn$ on1 /opp+ :5 ! curr5t is cut (f4 ,?is is q a common arrangem5t = small] telph]s1 b 9 ! l>g] ones a man travels ) ! telph] & load1 controll+ ! tra9 j z 9 ! case ( ! ord9>y trolley sy/em4 ,! v>i\s processes ( hoi/+ 9 m9es by electricity is closely ak9 to t ( traction1 s9ce1 aft] all1 an elevator is virtually a railway ) a #ajj-p]-c5t grade4 ,z su* "w is done spasmodically1 long p]iods ( re/ int]v5+ betwe5 actual p]iods ( "w1 a great deal ( en]gy is wa/$ by /eam hoi/+ eng9es1 :]e a c]ta9 pressure ( /eam 9 ! boil] mu/ be ma9ta9$ at all times4 ,= ?is reason electrical en]gy = hoi/+ has come rapidly into popul>ity 9 rec5t ye>s4 ,! ?rottl+ ( /eam to control spe$1 said ,mr4 ,f4 ,o4 ,blackwell 9 address+ ! ,am]ican ,in/itute ( ,m9+ ,eng9e]s1 ! necessity = rev]s+ ! eng9e1 ! v>iation 9 /eam pressure1 ! abs5ce ( cond5s+ app>atus1 ! cool+ & l>ge cle>ance ( cyl9d]s1 & ! cond5sation & leakage ( /eam pipes :5 do+ no "w1 are all aga9/ ! /eam hoi/+ eng9e4 ,"o ( ! l>ge/ hoi/+ eng9es 9 ! _w 0 rec5tly te/$ & f\nd to take sixty p\nds ( /eam p] indicat$ horse-p[] p] h\r4 ,! electric motor1 on ! o!r h&1 is ideal = int]mitt5t "w4 ,x wa/es absolutely no en]gy :5 at re/1 !re be+ no leakage or cond5sation4 ,its effici5cy is high1 f "o-qu>t] load to twice full load4 ,!re seems to be practically no diff]5ce z f> z ! elem5t ( dang] is conc]n$ betwe5 /eam & electric hoi/s4 ,! diff]5ce is l>gely "o ( economy4 ,! importance ( ?is is %[n by ! rec5t comp>isons 9 a gold m9e :i* has replac$ its /eam app>atus by electricity4 ,9 ?is m9e ! hoi/ moves ?r\gh ! %aft at a rate ( ov] twelve hundr$ feet p] m9ute1 elevat+ five hundr$ tons ( ore daily on d\ble-deck$ cages4 ,x is e/imat$ t ?is sy/em %[s an effici5cy ( #ge p] c5t1 tak+ into acc\nt losses ( all k9ds1 ) a result+ r$uction ( co/ ( f sev5 to tw5ty doll>s p] horse-p[] p] mon?4 ,results comp>+ v favorably ) ^! h be5 obta9$ also 9 "s ( ! m9es 9 ,g]many & ,bohemia1 :]e electricity has be5 introduc$ ext5sively 9 m9+4 ,9 "o ( ^! m9es ! daily hoi/+ capacity is tw5ty-sev5 hundr$ tons f a dep? ( ov] sixte5 hundr$ feet1 at a spe$ ( ov] fifty-two feet p] second4 ,9 ! ,com/ock m9e1 at ,virg9ia ,city1 ,nev41 electric hoi/s are us$ :i* obta9 _! p[] f a plant situat$ on ! ,tru*ee ,riv] ?irty-two miles away4 ,,electric ,,m9+ ,,pumps ,9 pump+1 :i* is always "o ( ! important items 9 m9+1 ! use ( electric p[] has be5 f\nd q z advantage\s z 9 ! o!r fields ( its application4 ,no special features are embodi$ 9 mo/ ( ! types ( m9+ pumps ov] ! rot>y & reciprocat+ types us$ = ord9>y purposes1 except p]haps a type ( pump kn[n z ! s9k+ pump4 ,?is is a movable pump t c be easily l[]$ f "o place to ano!r1 & has prov$ to be a great "t-sav] ov] /eam or air pumps us$ = simil> purposes4 ,= "s "t ! "q ( ! durability ( electric pumps 0 9 dispute1 b developm5ts 9 q rec5t ye>s seem to prove t1 9 "s in/ances at lea/1 su* pumps are practically inde/ructible4 ,! "q ( :at w\ld happ5 to an electric motor 9 a m9e if pumps & motors get flood$ has (t5 come up4 ,f te/s made rec5tly at ! ,univ]sity ( ,lige1 ,belgium1 x appe>s t a suitably design$ polyphase alt]nat+-curr5t motor ( a type l>gely us$ on ! cont95t ( ,europe 0 completely subm]g$ 9 wat]4 ,x 0 run = a qu>t] ( an h\r2 x 0 !n /opp$ & all[$ to rema9 subm]g$1 "u (ficial seal1 = tw5ty-f\r h\rs1 at ! end ( :i* "t x 0 aga9 run = a few m9utes4 ,x 0 next remov$ f ! wat]1 aga9 put "u seal1 & left to dry = tw5ty-f\r h\rs4 ,! insulation 0 !n te/$1 & ! motor 0 f\nd to be 9 p]fect ord]4 ,x w\ld be h>d to imag9e a te/ m sev]e ?an ?is4 ,z be>+ ^u ?is "q x is int]e/+ to note t among ! pumps 9 use ar\nd ,johannesburg1 ,s\? ,africa1 at ! beg9n+ ( ! ,anglo-,bo] ,w>1 !re 7 twelve ( a well-kn[n ,am]ican make1 ea* ( :i* 0 op]at$ by a #ej-;horse-p[] induction motor ( ,am]ican con/ruction ) ?ree #ae-kil[att trans=m]s4 ,:5 ! m9es 7 %ut d[n1 ^u ! break+ out ( ! w>1 ! wat] rose s rapidly t x 0 impossible to remove ! pumps1 motors1 trans=m]s1 etc41 & consequ5tly !y rema9$ "u #ejj to #a1jjj feet ( wat]4 ,two & a half ye>s lat]1 :5 peace 0 decl>$ 9 ,s\? ,africa1 ! wat] 9 ! %aft 0 pump$ out & ! electrical app>atus 0 remov$ to ! surface4 ,?ree ( ! motors 7 /ripp$ & completely rew\nd1 b to ! g5]al surprise ( ! exp]ts ! condition ( ! insulation indicat$ t ! rew9d+ might n be absolutely necess>y4 ,accord+ly ! o!r n9e motors 7 ?or\ghly dri$ 9 an ov5 & !n soak$ 9 oil4 ,aft] ?is treatm5t !y 7 rigidly te/$1 prov$ to be all "r1 & 7 at once re/or$ to regul> s]vice 9 ! m9e4 ,! trans=m]s 7 treat$ 9 ! same mann] z ! motors1 ) equally gratify+ results4 ,an int]e/+ illu/ration ( ! flexibility & adaptability ( electric motors = pump+ purposes is furni%$ by ! ,gneis5au m9e1 ne> ,dortmund1 ,g]many1 :]e a v l>ge electric m9+ plant 0 in/all$ 9 #aijc4 ,9 ?is in/ance ! pump is locat$ m ?an #a1bjj feet bel[ ! surface1 & ! difficulties ( in/all+ ! app>atus 7 s great1 on acc\nt ( ! small cross section ( ! %aft1 t x 0 necess>y to build up ! motor 9 ! pump+ *amb]1 ! mat]ial be+ transport$ ?r\gh ! wet %aft & ! w9d+ ( ! coils be+ p]=m$ 9 situ4 ,an int]e/+ use ( ! electric pump associat$ ) ! telephone 9 connection ) m9+ is not$ by ,mr4 ,w4 ,b4 ,cl>ke4 ,9 "o coal m9e1 :]e an electric pump is locat$ 9 a work$-out portion ( ! m9e1 ! circuits are s arrang$ t ! pump is />t$ f ! p[] h\se1 "s di/ance away4 ,ne> ! pump is plac$ a telephone transmitt] connect$ to a receiv] 9 ! p[] h\se4 ,to />t ! motors1 or to asc]ta9 :e!r ! pumps are work+ prop]ly1 ! eng9e] m]ely li/5s at ! telephone receiv]1 )\t leav+ 8 po/4 ,,electricity ,,9 ,,coal ,,m9+ ,9 coal m9+ ! effect ( ! use ( electrical ma*9]y has be5 revolution>y 9 rec5t ye>s1 p>ticul>ly 9 ! developm5t ( electric coal cutt]s4 ,! old me?od ( pick+ out coal by h&1 :]e ! m9] labor$ ) ! heavy pick1 work+ 9 all mann] ( cramp$ & dang]\s positions1 0 supplant$ a few ye>s ago by ! pun*] ma*9e1 work$ by /eam or compress$ air4 ,) ^! ma*9es ! coal 0 pick$ out j z 9 ! case ( ! h& me?od1 except t ! en]gy 0 d]iv$ f "s p[] o!r ?an muscul>4 ,s t :ile ^! ma*9es work$ m rapidly ?an ! h& picks1 !y utiliz$ ! same g5]al pr9ciple 9 apply+ _! en]gy4 ,)9 rec5t ye>s1 h[ev]1 v>i\s coal-cutt+ ma*9es h be5 devis$1 ) :i* ! coal 0 actually cut1 or saw$ out1 ^! ma*9es be+ peculi>ly well adapt$ to us+ ! electric curr5t4 ,! mo/ practical & popul> =m ( ma*9e is "o 9 :i* ! saw+ is done by an endless *a91 ! l9ks ( :i* are provid$ ) a cutt+ blade4 ,^! h be5 v g5]ally replac+ ! compress$-air or pick type ( ma*9e1 & _! popul>ity acc\nts l>gely = ! enorm\s increase 9 ! use ( coal-m9+ ma*9]y dur+ ! pa/ decade4 ,?us 9 #ahih !re 7 #b1fbb coal-m9+ ma*9es 9 use 9 ! ,unit$ ,/ates4 ,f\r ye>s lat] ?is numb] _h m ?an d\bl$1 ! increase be+ due l>gely to ! adoption ( *a9 ma*9es4 ,l electric locomotives1 & = simil> reasons1 ! coal-cutt+ ma*9es are l[1 broad1 flat ma*9es1 f eighte5 to tw5ty-eight in*es high4 ,!y re/ ^u a flat %oebo>d t c be mov$ easily along ! face ( ! coal4 ,an ord9>y ma*9e weighs 9 ! neighborhood ( a ton1 & requires two m5 to op]ate4 ,! app>atus is describ$ briefly z foll[s3 ,on an outside frame1 consi/+ ( two /eel *annel b>s & two angle irons rivet$ to /eel cross ties1 re/s a slid+ frame consi/+ ( a heavy *annel or c5tre rail1 to :i* is bolt$ ! cutt] head4 ,! cutt] head is made entirely ( two mill$ /eel plates1 :i* bolt toge!r1 =m+ ! front guide = ! cutt] *a94 ,?is *a91 :i* is made ( solid ca/ /eel l9ks connect$ by drop =ge /raps1 is c>ri$ ar\nd idl]s or sprockets plac$ at ea* end ( ! cutt] head & along ! *a9 guides at ! side to ! re> ( ! ma*9e1 :]e x engages ) & receives its p[] f a ?ird sprocket1 "u ! motor4 ,! electric motor1 :i* is ( ironclad multipol> type1 re/s ^u a /eel c>riage1 :i* =ms ! be>+ = ! ma9 %aft4444 ,a rev]s+ swit* is provid$1 s t ! truck c travel 9 ei!r direction1 & :5 ! ma*9e has rea*$ its /opp+ po9t1 ei!r =w>d or backw>d1 x is *eck$ by an automatic cut-(f4 ,! return travel is made 9 ab\t "o-f\r? ( ! "t requir$ to make ! cut4 ,9 ve9s ( coal ( a ?ickness f tw5ty-eight to ?irty in*es1 su* a ma*9e w cut ab\t "o hundr$ tons ( coal 9 a day4 ,! co/ ( production ) su* ma*9es has be5 e/imat$ at ab\t sixty-?ree c5ts a ton1 z aga9/ n9ety c5ts z ! co/ ( pick m9+ 9 rooms1--a sav+ ( ab\t tw5ty-sev5 c5ts a ton4 ,s9ce x is e/imat$ t = a co/ ( #aj1jjj an electrical equipm5t c be in/all$ capable ( work+ f\r su* ma*9es besides af=d+ p[] = light+1 pump+1 v5tilation ( ! m9e1 etc41 ?us sav+ some?+ l #ajj a day = ! op]ator1 ! great popul>ity ( ^! ma*9es is readily und]/ood4 ,aft] su* a ma*9e has be5 plac$ 9 position1 a cut "s f\r feet wide1 f\r or five in*es high1 & six feet deep c be made 9 five m9utes1 ) ! exp5diture ( v little en]gy on ! "p ( ! workm54 ,"o ( ! l>ge/ cutt+s ev] record$ by "o ( ^! ma*9es is #a1gjj squ>e feet 9 n9e & "o-half h\rs1 al?\gh ?is may h be5 exce$$ & n record$4 ,among ! sev]al advantages claim$ = ! *a9 ma*9e ov] ! old] pick ma*9es is ! small am\nt ( slack coal produc$1 & ! abs5ce ( ! rack+ vibrations t exhau/ ! workm51 &1 l ! air drills1 sometimes cause s]i\s diseases4 ,on ! o!r h& ! advocates ( ! pick ma*9es po9t out t !y c be us$ 9 m9es too n>r[ = ! introduction ( *a9 ma*9es4 ,!y %[ also t !re is a con/ant elem5t ( dang] f motor-driv5 ma*9es 9 m9es :]e ! quantity ( gas pres5t makes x necess>y to use safety lamps1 on acc\nt ( ! sp>k+ ( ! ma*9es :i* may produce explosions4 ,bo? ^! claims are valid1 b apply only to special cases1 or to c]ta9 m9es1 & d n affect ! g5]al popul>ity ( ! *a9 ma*9es4 ,!re are sev]al diff]5t types ( *a9 cutt+ ma*9es1 su* z long-wall ma*9es1 & %e>+ ma*9es1 b ^! ne$ n be consid]$ 9 detail "h4 ,! g5]al pr9ciple ^u :i* !y "w is ! same z ! ord9>y *a9 ma*9e1 ! diff]5ce be+ 9 ! me?od ( apply+ x = use 9 special situations4 ,,electric ,,light+ ,,( ,,m9es ,= _m obvi\s reasons ! ideal light = m9+ purposes is "o 9 :i* ! dang] f ! op5 flame is avoid$1 p>ticul>ly 9 well-v5tilat$ m9es1 or m9es "u c>eful sup]vision1 :]e ! dang] f inflammable gases is slight4 ,! inc&esc5t electric light1 !re=e1 has become practically indisp5sable 9 mod]n m9+ op]ations4 ,= c]ta9 purposes & 9 c]ta9 locations :]e an int5se light is desirable & :]e !re is no dang] f combu/ible gases1 arc lights are us$ to a limit$ ext5t4 ,b !re is con/ant dang] f ! op5 flame 9 us+ su* lights1 & also f ! connect+ wires lead+ to !m4 ,fur!rmore1 su* int5se light is n usually necess>y 9 ! n>r[ passages ( ! m9e4 ,to be sure1 !re is a c]ta9 elem5t ( dang] ev5 ) inc&esc5t lights on acc\nt ( ! possibility ( breakage ( ! globes1 & ( %ort-circuit+ :]e improp] wir+ has be5 done4 ,to ov]come z mu* z possible ! dang]s f ^! s\rces1 special precautions are tak5 9 wir+ m9es1 & special bulbs are us$4 ,9 g5]al ! inc&esc5t lamps z us$ 9 m9+ are made ( /\t r\nd bulbs ( ?ick glass :i* are n likely to crack f ! effects ( wat] dripp+ ^u !m :ile heat$4 ,z a fur!r protection x is cu/om>y to enclose ! bulbs 9 wire cages4 ,x is also cu/om>y to use l[-curr5t lamps ) a r high voltage1 al?\gh ?is mu/ be limit$1 z excessive voltage may 9 itself become a s\rce ( dang]4 ,,xiii ,,! ,,age ,,( ,,/eel ,! iron indu/ry has ( late ye>s become m & m m]g$ into ! /eel indu/ry1 z /eel has be5 gradually replac+ ! p>5t metal 9 ne>ly e field ( its =m] usefulness4 ,/eel is s mu* sup]ior to iron = almo/ e purpose & ! process ( mak+ x has be5 s simplifi$ by ,bessem]'s discov]y t x may ju/ly be said t civilization has em]g$ f ! ,iron ,age1 & ent]$ ! ,age ( ,/eel4 ,:ile iron is m9$ m ext5sively n[ ?an at any "t 9 ! hi/ory ( ! _w1 ! ultimate object ( mo/ ( ?is m9+ is to produce mat]ial = manufactur+ /eel4 ,we /ill speak ( boil] iron1 railroad iron1 iron %ips1 etc41 b ^! names are rem9isc5t1 = 9 ! con/ruction ( mod]n boil]s & mod]n %ips1 /eel is us$ exclusively4 ,9 ! pa/ decade x is probable t no railroad rails ev5 = ! smalle/ & *eape/ ( tracks h be5 made ( any?+ b /eel4 ,! la/ half ( ! n9ete5? c5tury has be5 "o ( triumph ( /eel manufacture & production 9 ,am]ica1 & at ! pres5t "t ! ,unit$ ,/ates /&s head & %\ld]s above any o!r nation 9 ?is indu/ry4 ,9 ! middle ( ! c5tury bo? ,g]many & ,engl& 7 great] produc]s ?an ,am]ica2 b by ! close ( ! c5tury ! annual output 9 ! ,unit$ ,/ates 0 above fifte5 million tons z aga9/ ,engl&'s t5 & ,g]many's sev52 & s9ce #aijj ?is lead has be5 greatly increas$4 ,! /eel indu/ry has become s great1 9 fact1 t x is a sort ( b>omet] ( trade & national progress4 ,! great advances 9 ! quantity ( /eel produc$ h be5 made possible by correspond+ advances 9 me?ods ( w9n+ ! iron ore f ! e>?4 ,m9+ ma*9]y has be5 revolutioniz$ at lea/ twice dur+ ! la/ half c5tury1 fir/ by improv$ ma*9es driv5 by /eam1 & aga9 by electricity & compress$ air4 ,ore is /ill m9$ to a limit$ ext5t by m5 ) picks & %ovels1 b ^! implem5ts n[ play s insignificant a "p 9 ! process t !y _c be consid]$ z important factors4 ,/eam %ovels1 automatic load]s & unload]s1 dynamite & bla/+ p[d]1 h tak5 ! place ( brawn & muscle1 :i* is n[ mo/ly exp5d$ 9 direct+ & guid+ m9+ ma*9]y r ?an 9 actually h&l+ ! ore4 ,,! ,,lake ,,sup]ior ,,m9es ,at ! pres5t "t ! greate/ iron-ore fields lie 9 ! ,lake ,sup]ior region1 & x is 9 ?is region t ! greate/ progress 9 m9+ me?ods has be5 made 9 rec5t ye>s4 ,!re are1 ( c\rse1 ext5sive m9es 9 o!r sections ( ! ,unit$ ,/ates1 b at lea/ ?ree-qu>t]s ( all ! iron produc$ 9 ,am]ica comes f ! ,lake ,sup]ior m9es1 & ! sy/ems ( m9+ pursu$ !re may be consid]$ z repres5tative ( ! mo/ advanc$ mod]n me?ods4 ,:]e ! iron ore ( ^! m9es is f\nd ne> ! surface ( ! e>?1 ! great sy/em ( op5-pit m9+ is practis$2 b z only a relatively small portion ( ! ore is s situat$1 modifications ( old] m9+ me?ods are /ill employ$4 ,( ^! ! ?ree mo/ important are kn[n z ov]head scoop+1 cav+1 & mill+4 ,9 ! ov]head me?od a %aft is sunk into ! e>? to a dep? ( sev]al hundr$ feet1 accord+ to ! dep? ( ! ore1 ?is %aft be+ l9$ ) timb]s = support4 ,f ?is %aft horizontal tunnels are made 9 all directions 9 ! ore deposits1 & ?r\gh ^! tunnels ! ore is convey$ to ! %aft & !nce to ! surface4 ,z ! ore is remov$ & ! e>? ?us honeycomb$ 9 all directions1 supports ( v>i\s k9ds mu/ be made to prev5t cav+4 ,= ?is purpose columns ( ! ore itself may be left1 or supports ( masonry or wood or /eel may be introduc$4 ,"u c]ta9 circum/ances1 h[ev]1 ^! supports are n employ$1 ! e>? be+ all[$ gradually to cave 9 at ! surface z ! ore is remov$1 ?is be+ ! me?od ( m9+ kn[n z cav+4 ,:]e ! ore deposit occurs 9 a favorable hillside ! mill+ sy/em is frequ5tly employ$4 ,9 work+ ?is sy/em a l>ge horizontal tunnel1 tw5ty or m feet 9 diamet]1 is dug into ! hillside4 ,p]p5dicul> %afts are !n sunk f ! top ( ! hill1 connect$ ) op5+s lead+ directly into ! top ( ! ma9 horizontal %aft4 ,by ?is arrangem5t ! ore1 :5 loos5$ 9 ^! p]p5dicul> %afts1 falls directly into ! b9s plac$ = its reception ab\t ! op5+s1 or into ! r[s ( c>s 9 wait+ to receive x4 ,9 ?is me?od dynamite & p[d] take ! place ( h& labor1 ! ma9 mass ( ore be+ dislodg$ & ?r[n into ! %aft by bla/+1 in/ead ( by h& labor4 ,b all ^! me?ods are ov]%ad[$ 9 magnitude by ! great op5 pit sy/ems1 :]e ! ore is tak5 f ! surface & h&l$ entirely by ma*9]y1 ! only "p play$ by ! m9]'s pick be+ t ( assi/+ 9 loos+ c]ta9 fragm5ts s t !y may be m easily seiz$ by ! ma*9es4 ,inde$1 ?is sy/em ( m9+ p>takes ( ! nature ( qu>ry+ r ?an t ( m9+ 9 ! ord9>y s5se1 ! ore be+ scoop$ f ! surface ( ! gr\nd4 ,"o naturally ?9ks ( a m9e z be+ subt]ranean2 b 9 ! great op5-pit m9es 9 ! ,lake ,sup]ior region1 :i* are ! l>ge/ m9es 9 ! _w1 all ! m9+ is done at ! surface ( ! e>?4 ,x %\ld n be und]/ood1 h[ev]1 t 9 su* m9es nature has left ! r$ iron ore expos$ at ! surface 9 any great quantities4 ,on ! contr>y1 x is usually cov]$ by a lay] ( e>? rang+ f a y>d to t5 or m y>ds 9 dep?1 & ?is1 ( c\rse1 mu/ be remov$ be=e op5-pit me?ods c be practis$4 ,prospect+ = su* deposits is !re=e j z necess>y z 9 cases :]e ! deposit is situat$ mu* deep] 9 ! e>?2 & ! bus9ess ( prospect+ by te/ pit m5 is z important an indu/ry z ev]4 ,:5 an available op5-pit m9e ( suffici5t ext5t has be5 locat$ ! gigantic task ( /ripp+ or remov+ ! ov]ly+ lay] ( e>? beg9s4 ,imm5se areas ( l& h be5 ?us /ripp$ 9 "s ( ^! und]tak+s1 no difficulties be+ consid]$ insurm\ntable4 ,if a small riv]-b$ lies 9 an unfavorable position1 ! c\rse ( ! riv] is *ang$ reg>dless ( exp5se4 ,f>ms & f>m h\ses are pur*as$ & lit]ally c>t$ away1 nei!r l& nor h\ses repres5t+ values wor? consid]+ :5 comp>$ ) ! /ratum ( ore b5ea? !m4 ,! s+le contract = /ripp+ "o area 9 ! ,lake ,sup]ior region 0 let = a sum am\nt+ to half a million doll>s4 ,z soon z a suffici5tly l>ge area has be5 /ripp$1 railroads are con/ruct$ into ! pit1 /eam %ovels are run into place1 & ! actual "w ( m9+ beg9s4 ,five %ovels full make a c>-load1 & "u ord9>y circum/ances ! five loads may be deliv]$ 9 z _m m9utes4 ,! numb] ( m5 requir$ to manipulate "o ( ^! /eam %ovels is f t5 to twelve4 ,! ore itself is frequ5tly s h>d t ! scoop ( ! %ovel c\ld n p5etrate x until loos5$ & brok5 up1 & x is ! bus9ess ( ! gang ( workm5 to d ?is & slide ! ore d[n )9 easy work+ di/ance ( ! %ovel4 ,?is is mo/ly done by bla/+ ) dynamite & p[d]1 little ( ! actual labor be+ p]=m$ by h&4 ,9 bla/+1 a deep hole is fir/ drill$ into ! ore ne> ! top ( ! embankm5t1 & into ?is hole a /ick ( dynamite is dropp$ & explod$4 ,?is enl>ges ! cavity suffici5tly s t a quantity ( bla/+ p[d] may be p\r$ 9 & set (f1 tumbl+ ! ore d[n )9 rea* ( ! %ovel4 ,?is ore is frequ5tly almo/ z h>d z iron itself1 _m ( ! pieces ?us dislodg$ be+ too l>ge = conv5i5t h&l+1 ei!r by ! /eam %ovel or 9 ! *utes at ! :>ves1 & mu/ be /ill fur!r brok5 up4 ,?is is sometimes done by ! m5 ) picks2 b 9 m9+ on a l>ge scale1 :]e ! deposit is all ( a v h>d nature1 cru%+ ma*9es are us$4 ,9 ?is mann] ! /eam %ovel is kept con/antly suppli$ ) ore = ! wait+ tra9 ( c>s4 ,^! tra9s are arrang$ on a track runn+ p>allel ) ! track f :i* ! /eam %ovel op]ates1 & at su* a di/ance t ! c5tre ( ! c> w be directly "u ! op5+ 9 ! bottom ( ! %ovel :5 x is swung ar\nd on its crane4 ,! eng9e] 9 *>ge ( ! locomotive draw+ ! tra9 /ops x 9 a position s t ! fir/ %ovelful ( ore w be dump$ into ! =w>d end ( ! fir/ c>4 ,z ea* successive %ovelful is deposit$1 repres5t+ ab\t "o-fif? ( a c>-load1 ! tra9 is pull$ or back$ along ! track ab\t "o-fif? ( a c>-l5g?4 ,9 ?is mann] x is only necess>y = ! /eam %ovel to be swung into ! same position & dump$ at ! same po9t ea* "t to insure ! prop] load+ ( ! c>s4 ,f :at has be5 said x w be se5 t 9 ?is op5-pit m9+ ! /eam eng9e & /eam locomotive /ill play a conspicu\s "p2 b 9 ! o!r =ms ( iron m9+1 electric or compress$-air motors are us$1 z mu* bett] adapt$ = und]gr\nd "w4 ,9 ! ,lake ,sup]ior region1 :]e ev]y?+ is done by ! mo/ mod]n me?ods1 ! use ( horses & mules = haul+ purposes is practically unkn[n4 ,! c>s us$ = haul+ ! ore are ( peculi> con/ruction4 ,! late/ types are built ( /eel ) a c>ry+ capacity ( fifty tons ( ore1 & are s made t by simply knock+ loose a few p9s _! bottoms op5 & dis*>ge ! ore into ! receiv+ b9s on ! :>ves1 or into ! *utes lead+ to ! wait+ boats4 ,a p]5nial problem 9 iron m9+1 :e!r surface or subt]ranean1 j z 9 all o!r k9ds ( m9+1 is ! removal ( accumulations ( wat]1 "s ( ^! m9es fill+ at ! rate ( f tw5ty-five to ?irty ?\s& gallons an h\r4 ,b an equally important problem is t ( remov+ moi/ure f ! ore itself4 ,obvi\sly e additional p\nd ( moi/ure adds to ! co/ & difficulty 9 h&l+1 & inasmu* z ?is ore mu/ be transport$ a di/ance ( some?+ l a ?\s& miles1 necessitat+ ?ree or f\r h&l+s 9 ! process1 ! aggregate am\nt ( wa/$ en]gy caus$ by ea* ton ( wat] is enorm\s4 ,x has be5 f\nd t at lea/ t5 p] c5t ( ! moi/ure may be dri$ out ( ! ore be=e %ipp+1 & t ! ore does n t5d to absorb moi/ure aga9 "u ord9>y circum/ances once x has be5 dri$4 ,?is is ( c\rse ( great advantage :]e x is f\nd necess>y to /ore x 9 heaps "s little "t be=e %ipp+4 ,,f ,,m9e ,,to ,,furnace ,9 mo/ indu/ries1 p>ticul>ly :]e ! p]c5tage ( wa/e products is l>ge1 x is f\nd advantage\s & economical to e/abli% factories z ne> ! s\rce ( supply ( raw mat]ial z possible4 ,b ! iron ore m9$ 9 ! ,lake ,sup]ior region is transport$ some?+ l a ?\s& miles be=e be+ deliv]$ to ! factories4 ,! "q naturally arises1 ,:y is n ! ore turn$ into pig iron or /eel +ots at once z ne> ! m\?s ( ! m9es z possible1 & s5t 9 ?is cond5s$ =m to ! factories1 ?us sav+ m ?an half ! co/ ( transportation8 ,! answ] is simple3 ! coal m9es & /eel factories lie 9 ! ,ea/1 "o e/abli%$ by nature1 ! o!r by man _m ye>s be=e iron ore 0 f\nd 9 ! ,lake region4 ,& x is f\nd j z *eap & easy to transport ! iron to ! coal regions z x w\ld be to transport ! coal to ! ore regions4 ,fur!rmore1 ! factories 9 ! neighborhood ( ,pittsburg & along ! s\!rn %ores ( ,lake ,erie & ,lake ,ont>io are ne> ! great c5tres ( civilization1 & are accessible ! ye> r\nd2 :ile ! ,lake ,sup]ior region is froz5 9 = at lea/ ?ree mon?s 9 ! ye>4 ,& s1 9 place ( a great traffic ( coal we/w>d to ! ,lake ,sup]ior regions1 !re is a great ea/w>d traffic ( ore1 by rail & wat]1 pass+ f ! m9es to furnaces & factories a ?\s& miles away4 ,inde$1 ?is is probably ! greate/ & mo/ rem>kable sy/em ( transportation 9 ! _w4 ,specially con/ruct$ tra9s1 :>ves1 boats1 & ma*9]y1 us$ = ?is s+le purpose1 & n duplicat$ ei!r 9 design or ext5t1 make ?is /up5d\s ent]prise a unique1 z well z a purely ,am]ican "o4 ,! transportation beg9s ) ! tra9 loads ( ore t run f ! m9es to ! lake %ore & out ^u ! :>ves built to receive !m4 ,^! :>ves are enorm\s /ructures1 sometimes half a mile 9 l5g?1 built up to ab\t ! height ( ! ma/s ( ore boats4 ,on ! sides & 9 ! c5tres ( ^! t[]+ /ructures are huge b9s = hold+ ! ore1 ^! b9s communicat+ directly ) ! holds ( ! ore /eam]s ti$ up alongside4 ,f\r tracks are frequ5tly laid on ! top ( ! :>ves1 & are s arrang$ t tra9s f\r abrea/ c dump ! ore into ! b9s1 or wait+ %ips1 at ! same "t4 ,if ! b9s are empty & boats wait+ to receive a c>go1 ! ore is dis*>g$ by long *utes into ! holds f ! c>s4 ,o!rwise ! b9s are fill$1 ! tra9s return+ to ! m9es z quickly z possible = fre% loads4 ,! boats = receiv+ ?is c>go are ( special design1 _m ( !m diff]+ v greatly 9 appe>ance f ord9>y ocean l9]s ( correspond+ size4 ,?is is p>ticul>ly true ( ! :ale-backs :i* h little 9 common 9 appe>ance ) ord9>y /eam]s except 9 ! matt] ( funnels2 & ev5 ^! are misplac$ /]nw>ds to a di/ance q out ( draw+ ) ! l5g? ( ! hull4 ,_! %ape is t ( ! ord9>y type ( subm>9e boat--t is1 cig>-%ap$--?is effect be+ obta9$ by a curv$ deck completely cov]+ ! place ord9>ily occupi$ by a flat deck4 ,a :eel-h\se1 l a battle-%ip's conn+-t[]1 is plac$ well =w>d1 support$ on /eel beams "s di/ance above ! curv$ deck = obs]vation purposes2 & eng9es1 boil]s1 & coal bunk]s occupy a small space 9 ! /]n4 ,! boat1 !re=e1 is mo/ly hold4 ,b ! :ale-backs =m only a small portion ( ! ore-fleet4 ,! ord9>y type ( boat con=ms m ne>ly to ! %ape ( ocean boats1 except t ! bridge1 :eel-h\se1 & eng9es are locat$ z 9 ! :ale-backs4 ,! b[s ( ^! boats are blunt1 ! desid]atum 9 su* craft be+ hull-capacity r ?an spe$4 ,= sea-wor?9ess !y are equal to any ocean boats1 z ! batt]+ waves ( ,lake ,sup]ior are q z p[]ful & ev5 m trea*]\s ?an ^? ( ! ,atlantic or ,pacific4 ,"s ( ^! boats are five hundr$ feet long1 equal to all b ! l>ge/ ocean vessels4 ,_! coal-c>ry+ capacity is relatively small1 s9ce coal+ /ations are num]\s at v>i\s po9ts on ! j\rney1 & e available in* ( space is utiliz$ = ! preci\s iron ore4 ,9 ord] to facilitate load+1 ! decks are lit]ally honey-comb$ ) hat*es1 "s boats hav+ fifte5 or sixte5 op5+s ext5d+ ! wid? ( ! deck4 ,by ?is arrangem5t ! "t ( load+ is r$uc$ to a matt] ( a few h\rs1 z a doz5 *utes1 ea* dis*>g+ sev]al tons ( ore p] m9ute1 soon fill ! yawn+ comp>tm5ts ) ! necess>y six1 eight1 or n9e ?\s& tons1 t make up ! c>go4 ,q rec5tly lake-navigators h le>n$1 :at riv]m5 h long kn[n1 t *eap transportation may be effect$ on a l>ge scale by b>ges & t[+4 ,be=e ! outbreak ( ! ,civil ,w> =ty ye>s ago1 ! ,mississippi riv] sw>m$ ) great c>go-c>ry+ /eam]s1 employ+ armies ( m5 & consum+ enorm\s quantities ( fuel4 ,b aft] ! w> ! exp]im5t 0 tri$ ( haul+ ! c>goes on b>ges t[$ by tug boats1 & ?is prov$ to be s mu* *eap] t ! fleet ( great riv] boats soon disappe>$4 ,9 some:at ! same way ! b>ge has come into use ( late ye>s 9 ! ore-traffic1 & ! great ore-/eam]s n[ t[ beh9d !m "o or two b>ges equal 9 c>ry+ capacity to !mselves4 ,9 ?is way ?ree %ips' c>goes ( ore are transport$ a ?\s& miles by a score ( m51 a doz5 on ! /eam] & ?ree or f\r on ea* ( ! b>ges4 ,! b>ges !mselves are rigg$ z %ips1 & if necess>y c %ift = !mselves by means ( sails atta*$ to _! /ubby ma/s4 ,b ^! are us$ only on special & unusual occasions1 z 9 case ( accid5tal p>t+ ( ! haws]s dur+ a /orm4 ,! problem ( load+ ! %ips at ! ore :>ves is a simple "o z comp>$ ) ! equally important "o ( transf]r+ ! ore f ! hold to tra9s ( c>s 9 wait+ at ! ea/]n end ( ! wat] r\te4 ,= f\r h&l+s ( ! ore are necess>y be=e x is f9ally deposit$ 9 ! furnaces 9 ! ea/4 ,! fir/ ( ^! is f ! m9e to c>s2 ! second f ! c>s to ! boats2 ! ?ird f ! boats to c>s2 & ! f\r? f ! c>s to ! bla/ furnaces4 ,= _m ye>s ab\t ! only h& "w done 9 any ( ^! processes 0 t ( transf]r+ f ! boats to ! ore-tra9s1 & ev5 "h automatic unload]s are n[ rapidly supplant+ ! t$i\s h& me?od4 ,by ! old] me?ods a travell+ crane1 or sw++ d]rick1 dropp$ a bucket into ! hold ( ! ore-vessel1 :]e workm5 %ovell$ x full ( ! r$ ore4 ,x 0 !n lift$ out by ma*9]y & ! cont5ts dump$ into c>s 9 mu* ! same mann] z t ( ! /eam %ovel 9 ! m9es4 ,rec5tly1 h[ev]1 a ma*9e has be5 p]fect$ :i* scoops up ! ore f ! %ip's hold & transf]s x to ! c>s )\t ! aid ( %ovell]s4 ,! only human aid giv5 ?is gigantic ma*9e is to guide x by means ( controll+ lev]s--to furni% bra9s = x1 9 %ort--! muscle be+ furni%$ by /eam p[]4 ,! great arm ( ?is automatic unload]1 resembl+ ! sweep ( ! old-fa%ion$ well 9 pr9ciple1 moves up & d[n1 bury+ ! jaws ( ! %ovel into ! ore 9 ! hold1 & pull+ !m out aga9 fill$ ) ore1 ) monoton\s regul>ity1 quickly empty+ ! vessel "u ! guidance ( half a doz5 m51 & p]=m+ ! labor ( hundr$s4 ,?us ! la/ field ( activity = ! labor] & 8 %ovel1 9 ! iron-ore indu/ry1 has be5 usurp$ by me*anical devices4 ,f ! "t ! ore is tak5 f ! m9e until x appe>s z molt5 metal f ! furnaces1 x is n t\*$ except by me*anisms driv5 by /eam1 compress$ air1 or electricity4 ,& yet1 s rapid is ! gr[? ( ! iron & /eel indu/ry t !re is almo/ always a dem& = m workm54 ,= ?is reason1 & p]haps because ( ! ,am]ican _s among workm51 innovations 9 ! way ( labor-sav+ ma*9]y are n resi/$ among ! m9e labor]s4 ,! ,am]ican workman seldom resi/s or attacks ma*9]y on ! gr\nd t x ?r[s him out ( a job1 z does 8 ,engli% c\s94 ,x w\ld be unju/ to attribute ?is attitude to sup]ior acum5 on ! "p ( ! ,am]ican workman1 & x is probably a diff]5ce 9 conditions & surr\nd+s t acc\nts = ! diametrically opposite views held by labor]s on ! two sides ( ! ,atlantic4 ,b aft] all1 results mu/ speak = !mselves1 & ! advantage all lies 9 favor ( ! progressive attitude ( ! we/]n labor]1 if we may judge by ! relative social /atus & f9ancial /&+ ( ,european & ,am]ican workm54 ,,! ,,conv]sion ,,( ,,iron ,,ore ,,into ,,iron ,,& ,,/eel ,s9ce /eel is a comp\nd sub/ance compos$ ess5tially ( two elem5t>y sub/ances 9 v>y+ proportions1 x appe>s t ! "n /eel1 l wood1 ref]s to a class ( :i* !re are sev]al v>ieties4 ,?is1 ( c\rse1 is ! case1 b = ! mom5t we may consid] /eel z a s+le sub/ance compos$ *iefly ( iron & conta9+ a c]ta9 p]c5tage ( c>bon4 ,9 ?is respect x resembles ca/ iron1 /eel hav+ a small] am\nt ( c>bon4 ,wr\ght iron1 on ! o!r h&1 conta9s no c>bon at all1 or at lea/ only a trace ( x4 ,b :atev] ! ultimate de/9y ( iron ore--:e!r x is to become ari/ocratic manganese /eel1 or plebeian ca/ iron--x mu/ fir/ pass ?r\gh c]ta9 processes be=e be+ conv]t$4 ,to extract ! pure iron f ! iron ore x is necess>y to heat ! ore 9 a furnace conta9+ a c]ta9 quantity ( coal1 coke1 or *>coal1 & lime/one4 ,! furnaces us$ 9 ?is process are kn[n z bla/-furnaces1 & 9 ^! ab\t "o ton ( iron is extract$ = e two tons ( ,lake ,sup]ior ore1 "o & a qu>t] tons ( coke1 & half a ton ( lime/one us$4 ,^! quantities are by no means con/ant1 ( c\rse1 b !y may be tak5 z repres5t+ r\ghly ! relative am\nts ( mat]ial t mu/ be f$ into ! furnaces4 ,l ev]y?+ else 9 ! _w ( iron & /eel1 ^! bla/-furnaces h und]gone revolution>y improvem5ts dur+ ! pa/ qu>t] ( a c5tury4 ,f be+ mo/ dang]\s & de/ructive /ructures caus+ frightful loss ( life & produc+ only ab\t "o ton ( iron a day = e man work+ ab\t !m1 z =m]ly1 !y h n[ become relatively h>mless mon/]s1 capable ( turn+ out six times t quantity ( ore = ea* man employ$4 ,! old] bla/-furnace 0 a huge1 *imney-l /ructure1 p]haps a hundr$ feet high1 into :i* ! ore1 coal1 & lime/one 7 p\r$4 ,mo/ ( ! "w ab\t ^! furnaces 0 done by manual labor1 or at lea/ manual labor 0 an active assi/ant to ! ma*9]y us$ 9 manipulat+ ! furnaces4 ,! top ( ! furnace 0 clos$ 9 by a great movable lid1 or bell1 & ! mat]ial = *>g+ x 0 haul$ up ! sides by elevators & dump$ 9 at ! top4 ,ab\t ! top ( ! furnace 0 con/ruct$ a /ag+ ^u :i* ! workm5 /ood1 an elevator %aft connect+ ! /ag+ ) ! gr\nd4 ,! ore & o!r mat]ials 7 br\ght to ! foot ( ! %aft on c>s f :i* x 0 %ovell$ into peculi>ly design$ :eelb>r[s1 trundl$ to ! elevator1 & haul$ to ! top4 ,9 ord] to dump ! :eelb>r[ loads into ! furnaces x 0 necess>y to raise ! bell4 ,?is 0 always dang]\s1 & frequ5tly result$ 9 ! suffocation or injury ( ! workm5 on ! /ag+4 ,= :5 ! bell 0 rais$ !re 0 an escape ( poison\s gases1 :i* might fl>e out 9 a %eet ( flame1 ) ! possibility ( burn+ or suffocat+ ! workm54 ,! fumes f ^! gases1 if inhal$ 9 small quantities1 might simply cause c\gh+1 hicc\gh+1 or dizz9ess2 b :5 inhal$ 9 l>ge quantities !y /ruck d[n a man l ! fumes ( *lor(orm1 suffocat+ him 9 a few seconds if he 0 n remov$ at once into a pur] atmosph]e4 ,inde$1 ! likelihood ( ?is 0 s great t at _m ( ^! furnaces a special workman 0 detail$ to take ! position on ! /ag+1 well out ( range ( ! gas1 8 sole duty be+ to rescue any ( ! m5 :o might be ov]come1 & hurry !m z quickly z possible d[n ! elevator %aft into ! pure atmosph]e bel[4 ,x 0 n an uncommon ?+ 9 ! neighborhood ( ^! old] furnaces to see /ret*$ ab\t on ! gr\nd at ! base sev]al workm5 9 v>i\s /ages ( suffocation4 ,=tunately1 by use ( precaution>y measures1 fatal accid5ts 7 r unusual1 ! m5 be+ ov]come only tempor>ily1 & usually recov]+ quickly & return+ to "w4 ,b ! poison\s gas com+ f ! top ( ! furnace 0 n ! only1 nor ! wor/1 dang] con/antly m5ac+ ! m5 on ! /ag+4 ,_! greate/ dread 0 ! possibility ( explosions occurr+ 9 ! furnace1 :i* might hurl ! bell into ! air & deluge ! upp] /ructure ) molt5 metal4 ,aga9/ ?is possibility !re 0 no safegu>d 9 ! old] furnaces1 explosions occurr+ )\t w>n+ & frequ5tly ) t]rible effects4 ,b =tunately ^! old] types ( furnaces are be+ rapidly replac$ by ! new] =ms 9 :i* ! dang] to life1 at lea/ f gas & explosions1 is m9imiz$4 ,& ev5 9 ! old] furnaces1 improvem5ts 9 ! /ructure ( ! bell & 9 me?ods ( fill+ h greatly less5$ ! dang]s4 ,9 ! mod]n type ( bla/-furnace ! "w at ! top =m]ly p]=m$ by m5 on ! /ag+ is accompli%$ entirely by ma*9]y4 ,! g5]al appe>ance ( ^! furnaces is t ( huge iron pipes or kettles m\nt$ on sev]al iron legs4 ,! out] /ructure1 or %aft1 is con/ruct$ ( plate iron1 b ?is is l9$ ) fire brick ( consid]able ?ickness1 & may h a wat] jacket int]pos$ betwe5 ^! bricks & ! %aft4 ,ab\t ?is l>ge kettle are small] kettles ( some:at simil> %ape hav+ pipes lead+ f _! tops to ! l>g] /ructure4 ,^! small] kettles are ! /oves us$ 9 produc+ ! hot air = ! furnace4 ,! work+ capacity ( "s ( ^! furnaces is 9 ! neighborhood ( a ?\s& tons ( iron a day1 al?\gh ! av]age furnace produces only ab\t half t quantity4 ,! p[]ful ma*9]y us$ = *>g+ ^! mon/] caldrons hauls ! ore & o!r *>g+ mat]ials to ! top & dumps x 9 c>-load lots4 ,9 ! old] me?ods ( manufactur+ /eel1 ! cont5ts ( ! bla/-furnaces 7 fir/ drawn (f into molds & all[$ to cool into :at is kn[n z pig-iron4 ,x 0 !n necess>y to re-heat ?is iron & treat x by ! v>i\s me?ods = produc+ ! k9d ( /eel desir$4 ,by ! new] me?ods1 h[ev]1 "t & money are sav$ by conv]t+ ! liquid iron f ! bla/-furnace directly into /eel )\t go+ ?r\gh ! transitional /age ( cool+ x into pigs4 ,pigs ( iron are /ill made 9 enorm\s quantities1 to be sure1 b mo/ly = %ipm5t to di/ant places or = /ores z /ock mat]ial4 ,= /ati/ical purposes1 h[ev]1 ! entire product ( ! bla/-furnace1 :e!r liquid or solid1 is kn[n z pig iron4 ,! old] me?od ( remov+ ! iron f ! bla/ furnaces 0 by tapp+ at ! op5+ ne> ! bottom1 ! /ream ( liquid iron be+ all[$ to fl[ into a connect$ s]ies ( s& molds1 ea* mold be+ ab\t ?ree feet long by ?ree or f\r in*es wide4 ,! bottom ( ^! molds 0 flat b z ! metal cool$ 9 !m ! upp] surface became r\nd 9 %ape1 assum+ a fanciful resemblance to a pig's back4 ,9 ?is mold+ a great am\nt ( "t 0 wa/$ 9 ! sl[ process ( cool+1 & a l>ge exp5diture ( en]gy wa/$ 9 ?is h&l+ & re-h&l+ ( ! metal4 ,9 mod]n smelt+ works1 h[ev]1 pigs are no long] ca/ 9 s& molds1 ! molt5 metal f ! furnace be+ dis*>g$ directly into iron molds atta*$ to an endless *a94 ,^! molds are long1 n>r[1 & %all[1 hav+ ! g5]al %ape ( s& molds4 ,ea* mold z x passes b5ea? ! op5+ 9 ! furnace rema9s j long en\gh to receive ! requisite am\nt ( metal to fill x1 & !n moves on to a po9t :]e x is ei!r spray$ ) wat]1 or cool$ by actually pass+ ?r\gh a tank ( wat]1 em]g+ f ?is ba? ) ! metal suffici5tly solidifi$ s t x may be dropp$ into a wait+ c> at ! turn+ po9t ( ! endless *a94 ,9 ?is mann] ! *>ge f ! bla/-furnace may be drawn1 cool$1 & conv]t$ into pigs1 load$ into c>s1 & haul$ away )\t extra h&l+s or loss ( "t1 ! :ole process occupy+ practically no m "t ?an ! initial /ep ( tapp+ by ! old] me?od4 ,:]e ! cont5ts ( ! bla/-furnace are to be conv]t$ into /eel at once1 ! molt5 metal is run (f into movable tanks :i* c>ry x directly to ! /eel furnaces4 ,^! tanks1 hold+ p]haps tw5ty tons ( metal1 are made ( ?ick iron l9$ ) fire brick1 & arrang$ on l[1 flat c>s design$ specially = ! purpose4 ,^! tanks are run "u ! sp\t ( ! furnace1 fill$ ) molt5 metal1 & drawn to ! /eel works1 possibly five miles away4 ,z a rule1 ! di/ance is mu* less1 b z f> z ! condition ( ! metal is conc]n$ di/ance seems to make little diff]5ce1 z ev5 at ! extreme di/ance !re is no app>5t cool+ ( ! see?+ mass4 ,! int5se heat giv5 (f by ^! tra9s necessitates specially con/ruct$ c>s1 tracks1 bridges1 & cross+s4 ,! de/9ation ( ?is tra9 load ( iron pots is ! mix]--a great #bjj-ton kettle 9 :i* ! products f ! v>i\s furnaces are mix$ & r5d]$ uni=m 9 quality4 ,on ! arrival ( ! tra9 at ! mix]1 ,titanic ma*9]y seizes ! tw5ty-ton pots & dumps _! cont5ts bodily into ! gl[+ pool 9 ! great crucible4 ,l ! fill+ process1 ?is op]ation occupies only a few m9utes4 ,f ! mix] ! metal is p\r$ out into ladles & transf]r$ imm$iately to ! conv]t]--! important developm5t ( ,sir ,h5ry ,bessem]'s discov]y t has made possible ! mod]n /eel indu/ry4 ,?is conv]t] resembles 9 %ape "s ( ! old mort>s us$ 9 ! ,am]ican ,civil ,w>--b>rel-%ap$ /ructures susp5d$ v]tically by trunnions at ! middle & hav+ an op5+ at ! top4 ,into ?is op5+ at ! top ! metal f ! mix] is p\r$ & :5 ! conv]t] has be5 suffici5tly *>g$ a bla/ ( cool$ air is bl[n 9 at ! bottom ?r\gh ! molt5 metal4 ,?is bla/ em]ges at ! top z a long ro>+ flame1 ( a r$ color at fir/ b gradually *ang+ into :ite1 & !n fa9t blue4 ,^! *anges 9 color are indicative ( ! *anges t are tak+ place 9 ! metal1 & ! appe>ance ( a c]ta9 %ade ( color indicates t ! conv]sion into /eel is complete1 & t x is "t = %utt+ (f ! bla/ ( air4 ,any mi/ake 9 ?is matt]--ev5 ! v>iation ( ?irty seconds' "t--means a loss ( ?\s&s ( doll>s 9 ! quality ( /eel produc$4 ,! man ^: duty x is to det]m9e ?is important po9t1 !re=e1 holds an exceptionally delicate & responsible position1 & receives pay accord+ly4 ,9 decid+ ! exact mom5t :5 ! bla/ %all be turn$ (f1 ?is workman is guid$ entirely by ! s5se ( sight4 ,m\nt$ on a plat=m comm&+ ! be/ possible view ( ! m\? ( ! conv]t] & we>+ gre5 glass goggles ( special con/ruction1 ?is man wat*es ! *ange ( color 9 ! flame until a c]ta9 %ade is rea*$--a %ade t to ! ord9>y untra9$ obs]v] does n diff] 9 appe>ance f t ( a mom5t be=e--:5 he gives ! signal to %ut (f ! bla/4 ,:5 ?is signal is giv5 ! cont5ts ( ! conv]t] is no long] common-place ca/ iron1 b /eel1 ready to be mold$ into rails1 boil]s1 or a ?\s& & "o o!r useful ?+s4 ,! cont5ts ( ! conv]t] may n[ be drawn (f z liquid /eel into molds ( any desir$ %ape & size1 & :5 cool$ w be ready = %ipm5t4 ,b 9 ! great /eel factories ! metal is n ord9>ily all[$ to cool completely be=e be+ s5t to ! roll+ mills1 be+ drawn (f into molds plac$ along ! surface ( small1 flat c>s4 ,^! molds are rectangul>1 ord9>ily f\r or five feet high by less ?an two feet 9 diamet]4 ,! metal is p\r$ into op5+s 9 ! top ( ea* mold1 & all[$ to cool1 solidify1 & to contract en\gh to p]mit ! out] cas+s ( ! molds to be pull$ (f by ma*9]y1 leav+ ! gl[+ +ots ( /eel ready = mold+ by ma*9]y 9 ! mills4 ,! process j describ$ is ! "o by :i* ,bessem] /eel is made4 ,!re is ano!r important process 9 use1 ! op5 he>? me?od1 :i* diff]s consid]ably f ?is2 b be=e consid]+ ?is process some?+ m %\ld be said ( ! man ^: discov]ies made possible ! mod]n /eel indu/ry4 ,,sir ,,h5ry ,,bessem] ,9 ! hi/ory ( ! progress ( sci5ce & inv5tion "s "o great "n is usually pre-em95tly associat$ ) epo*-m>k+ advances1 al?\gh !re may be a clu/] ( important b m9or associates4 ,?is is true 9 ! hi/ory ( ! mod]n /eel indu/ry1 & ! c5tral "n "h is t ( ,sir ,h5ry ,bessem]4 ,bessem] 0 born at ,*>lton1 ,engl&1 on ,jan4 #ai1 #ahac4 ,always ( an inv5tive turn ( m9d1 8 att5tion 0 fir/ direct$ to improv+ ! me?ods !n 9 use = ! manufacture ( /eel1 :ile exp]im5t+ ) ! manufacture ( guns4 ,aft] sev]al ye>s ( exp]im5t+ 9 8 little iron works ne> ,london1 he rea*$ "s def9ite results :i* he ann\nc$ to ! ,briti% ,association 9 #ahef4 ,9 ?is pap] he describ$ a process ( conv]t+ ca/ iron into /eel by remov+ ! excess ( c>bon 9 ! molt5 metal by a bla/ ( air driv5 ?r\gh x4 ,?is pap]1 9 %ort1 describ$ ! g5]al pr9ciples /ill employ$ 9 ! ,bessem] process ( manufactur+ /eel4 ,& al?\gh ! fir/ simple process describ$ by ,bessem] has be5 modifi$ & supplem5t$ 9 rec5t ye>s1 x 0 9 ?is pap] t ! process :i* plac$ /eel ^u ! m>ket z a comp>atively *eap1 & inf9itely sup]ior1 sub/itute = ord9>y iron1 0 fir/ disclos$4 ,?is fam\s pap] be=e ! ,briti% ,association ar\s$ great int]e/ among ! ,engli% ironma/]s1 & applications = lic5ses to use ! new process 7 made at once by sev]al firms4 ,b ! success atta9$ by ^! firms 0 any?+ b satisfactory1 al?\gh ,bessem] himself 0 soon able to manufacture an entirely satisfactory product4 ,! disappo9t$ ironma/]s1 !re=e1 return$ to ! e>li] processes1 ! inv5tor himself be+ ab\t ! only practical ironma/] :o p]si/$ 9 us+ x4 ,recogniz+ ! defects 9 8 process1 ,bessem] set ab\t ov]com+ !m1 & at ! end ( two ye>s he _h s succe$$ 9 p]fect+ 8 me?ods t 8 product1 equal 9 e respect to t ( ! old] process1 c\ld be manufactur$ at a great sav+ ( "t & money4 ,b ! ironma/]s 7 n[ skeptical1 & refus$ to be aga9 inveigl$ into apply+ = lic5ses4 ,bessem]1 !re=e1 ) ! aid ( fri5ds1 erect$ ext5sive /eel works ( 8 own at ,%effield1 & began manufactur+ /eel 9 op5 competition ) ! o!r /eel op]ators4 ,! price at :i* he 0 able to sell 8 product & realize a pr(it 0 s mu* bel[ ! actual co/ ( manufacture by ! old] process1 t !re 0 soon con/]nation 9 ! ranks ( 8 rivals4 ,= :5 x became kn[n t ! firm ( ,h5ry ,bessem] ,co4 0 sell+ /eel at a price some?+ l "o hundr$ doll>s a ton less ?an ! ord9>y m>ket price1 !re 0 b "o ?+ left = ! ironma/]s to d--surr5d]1 & apply = lic5ses to be all[$ to use ! new process4 ,by ?is means1 & ?r\gh ! pr(its ( 8 own e/abli%m5t1 ,bessem] ev5tually amass$ a well-e>n$ =tune4 ,moreov]1 he 0 honor$ 9 due c\rse by a fell[%ip 9 ! ,royal ,society1 & knight$ by 8 gov]nm5t4 ,"o o!r "n is usually associat$ ) t ( ,bessem] 9 ! practical developm5t ( ! inv5tor's orig9al idea4 ,t is ! "n ( ,rob]t ,mu%et1 & ! ,bessem]-,mu%et process is /ill 9 use4 ,mu%et's improvem5t ov] ,bessem]'s orig9al process 0 t ( add+ a c]ta9 quantity ( spiegeleis51 or iron conta9+ manganese1 :i*1 = "s reason n well und]/ood1 simplifies ! process ( /eel mak+4 ,mu%et1 !re=e1 mu/ be consid]$ z ! discov]] ( a useful1 ?\gh n an absolutely ess5tial1 accessory to ! ,bessem] process4 ,,op5-,,he>? ,,me?od ,9 ! op5-he>? me?od ! metal f ! bla/-furnaces is n s5t to ! conv]t]1 b is p\r$ into ov5-l /ructures built ( fire brick1 & 9 ^! heat$ to a t]rific temp]ature4 ,?is heat has ! same effect ^u ! metal z ! bla/ ( air 9 ! ,bessem] conv]t]1 & ?is op5-he>? process has become v popul> = manufactur+ c]ta9 k9ds ( /eel4 ,:ile 9 ! me?od ( application ?is process diff]s greatly f t ( ,bessem]1 x diff]s l>gely 9 ! fact t ! oxyg5 necess>y to burn (f ! c>bonic oxide1 silicon1 etc41 is made to play ov] ! molt5 mass in/ead ( pass+ ?r\gh x4 ,x has be5 not$ t ! old type ( bla/-furnace gave (f great quantities ( combu/ible gases :i* became wa/e products4 ,ev5 gases conta9+ some?+ l #bj or #be p] c5t4 ( c>bonic acid may be highly inflammable1 & ?us an enorm\s quantity ( valuable fuel 0 con/antly wa/$4 ,9 "s furnaces1 to be sure1 !y 7 put to practical use = heat+ ! bla/1 b z ! quantities giv5 (f 7 greatly 9 excess ( ! am\nt necess>y = ?is purpose1 !re 0 a con/ant loss ev5 ) su* furnaces4 ,q rec5tly x has be5 f\nd t ! gases c be us$ directly 9 gas eng9es1 develop+ ?ree or f\r times z mu* en]gy 9 ?is way z if !y 7 us$ z fuel "u ord9>y /eam boil]s4 ,^! eng9es are n[ us$ = op]at+ ! roll+-mill ma*9]y1 & ! ma*9]y ( %ops adjo9+ ! furnaces1 :i*1 h[ev]1 mu/ n be situat$ at any v great di/ances f ! furnaces4 ,?is acc\nts p>tly = ! gr\p+ toge!r ( bla/-furnaces1 roll+ mills1 & ma*9e %ops1 ! economical feature ( ?is arrangem5t be+ s great t segregat$ e/abli%m5ts f9d x next to impossible to compete 9 ! op5 m>ket ) su* communities "u ! conditions prevail+ 9 ! /eel indu/ry4 ,,alloy ,,/eels ,! introduction ( ,krupp /eel1 or nickel1 = armor plates1 a few ye>s ago1 call$ att5tion 9 a popul> way to ! fact t = c]ta9 purposes pure /eel--t is1 iron plus a c]ta9 quantity ( c>bon--0 n z useful z an alloy ( /eel ) "s o!r metal4 ,an alloy 0 a great improvem5t ov] ord9>y /eel or iron plates us$ 9 w>f>e2 b 9 ! m peaceful pursuits1 z well z 9 w>f>e1 c]ta9 alloy$ /eels1 su* z *rome /eel1 tung/5 /eel1 & manganese /eel play a v important "p4 ,*rome /eel1 = example1 9 ! =m ( projectiles1 is ! mo/ dread$ enemy ( nickel-/eel armor plates1 because ( ! h>dness & ela/icity ( armor-pi]c+ projectiles made ( x4 ,su* a /eel conta9s ab\t two p] c5t4 ( *romium ) ab\t "o or two p] c5t4 ( c>bon1 :i* :5 sudd5ly cool$ is extremely h>d & t\gh4 ,?is k9d ( /eel & manganese /eel are ! be/ gu>ds aga9/ ! burgl> & safe-bl[]1 z !y resi/ ev5 v highly temp]$ & h>d5$ drills4 ,z ?is /eel is relatively *eap to manufacture1 x is frequ5tly us$ 9 ! con/ruction ( safes & burgl>-pro( grat+s4 ,= ?is purpose1 h[ev]1 x is sometimes comb9$ 9 alt]nate lay]s ) s(t wr\ght iron1 ! /eel resi/+ ! po9t ( ! drill1 :ile ! iron furni%es ! necess>y ela/icity to resi/ ! bl[s ( ! sl$ge4 ,! b>s us$ 9 mod]n jails & prisons are (t5 made 9 a simil> mann] ( alt]nate %ea?s ( iron & *rome /eel4 ,aga9/ ! "t-honor$ hack-saw1 ! bugbe> ( prison (ficials = g5]ations1 su* b>s an in* & a qu>t] 9 diamet] (f] an almo/ insurm\ntable ob/acle2 & !y are equally effective aga9/ a heavy sl$ge hamm]4 ,at lea/ "o case is record$ 9 :i* ! use ( ^! composite b>s result$ 9 a disa/r\s fire 9 a prison4 ,a small blaze hav+ />t$ 9 ! basem5t ( ?is prison1 attempts to rea* x ) a /ream ( wat] 7 defeat$ by ! b>s ( ! /eel grat+s at ! w9d[s1 :i* w\ld n admit ! nozzle ( ! hose4 ,a corps ( m5 arm$ ) hack-saws1 cr[-b>s1 & sl$ges attack$ ?is grat+1 :i*1 if made ( ord9>y /eel1 c\ld h be5 readily brok54 ,b aga9/ ^! composite b>s !y produc$ no appreciable effect4 ,mean:ile ! fire ga9$ rapidly1 ?reat5+ ! build+ & its eight hundr$ inmates1 & 0 only *eck$ aft] holes _h be5 made ?r\gh fire-pro( floors & ceil+s = admitt+ ! nozzle4 ,manganese /eel is peculi> 9 becom+ ductile by sudd5 cool+1 & brittle on cool+ sl[ly--precisely ! rev]se ( ord9>y /eel4 ,x conta9s ab\t #a4ej p] c5t4 ( c>bon1 & ab\t #ab p] c5t4 ( manganese4 ,if a small quantity ( manganese1 t is1 #a or #b p] c5t41 is us$ ! /eel is v brittle1 & becomes m s z great] quantities ( ! manganese are us$1 up to ab\t #e p] c5t4 ,f t po9t1 h[ev]1 x becomes m ductile z ! quantity ( manganese is increas$1 until at ab\t #ab p] c5t4 x rea*es an ideal /ate4 ,:5 us$ = safes & money vaults ?is /eel has "o great advantage ov] *rome /eel--x is n affect$ by heat4 ,by us+ a bl[-pipe & heat+ a limit$ area ( /eel1 ! burgl> is able to draw ! temp] ( ord9>y /eel to a suffici5t dep? s t he c drill a hole to admit a *>ge ( dynamite2 b manganese /eel reta9s its temp] "u ! bl[-pipe no matt] h[ long x may be appli$4 ,aga9/ attacks ( ! sl$ge1 h[ev]1 x is probably inf]ior to *rome /eel4 ,l manganese /eel1 tung/5 /eel reta9s its temp] ev5 :5 heat$ to high temp]atures4 ,= ?is reason x is us$ frequ5tly 9 mak+ tools = metal-la! "w :]e ?ick slices ( iron are to be cut1 z ev5 at r$ heat su* a tool cont9ues to cut (f metal *ips z readily z :5 kept at a l[] temp]ature4 ,?is /eel conta9s f #f to #aj p] c5t4 ( tung/51 a metallic elem5t ) :i* we h previ\sly made acqua9tance 9 our /udies ( ! inc&esc5t lamp4 ,,xiv ,,"s ,,rec5t ,,triumphs ,,( ,,appli$ ,,sci5ce ,n long ago a little company ( m5 met 9 a lecture hall ( ,columbia ,univ]sity to discuss c]ta9 que/ions 9 appli$ sci5ce4 ,x 0 a small ga!r+1 & its proce$+s 7 s unspectacul> z to be e/eem$ wor? only a few l9es ( newspap] space4 ,! v "n--,society ( ,electro-,*emi/ry--seem$ to m>k x z hav+ to d ) ?+s t are cavi> to ! g5]al4 ,! "n seems to smack ( fumes ( ! laboratory1 f> remov$ f ! int]e/s ( ! man 9 ! /reet4 ,yet ,pr(essor ,*&l] said 9 8 address ( welcome to ! memb]s ( ! society1 t ?\gh !irs 0 ! v y\nge/ ( sci5tific organizations1 he c\ld confid5tly pr$ict = x a future position outrank+ t ( all its si/] societies2 & 8 pr$iction 0 bas$ on ! belief t electro-*emi/ry is de/9$ to revolutionize va/ & important dep>tm5ts ( mod]n indu/ry4 ,a majority ( ! heat-us+ me?ods ( me*anics w owe _! future developm5t to ! new sci5ce4 ,9 a ^w1 !n1 despite its repell5t "n1 ! society 9 "q has to d ) affairs t are ( ! utmo/ importance to ! man 9 ! /reet4 ,?\gh its memb]s may sometimes deal 9 occult =mulas & ab/ruse calculations1 yet ! f9al goal ( _! /udies has to d n ) ab/ractions b ) practicalities1--) ! sav+ ( fuel1 ! smelt+ ( metals1 ! manufacture ( commodities4 ,b !ory 9 ! ma9 mu/ prec$e practice--! *ild creeps be=e x walks4 ,! lat] developm5ts ( indu/rial *emi/ry1 says ,sir ,william ,ramsey1 owe _! success entirely to ! gr[? ( *emical !ory2 & x is obvi\s1 he adds significantly1 t t nation :i* possesses ! mo/ compet5t *emi/s1 !oretical & practical1 is de/9$ to succe$ 9 ! competition ) o!r nations = comm]cial supremacy & all its concomitant advantages4 ,=tunately ?is int]dep5d5ce ( sci5ce & indu/ry is n a m]e matt] ( prophecy--= ! future t5se is nev] q s satisfy+ z ! pres5t4 ,va/ly important *anges h already be5 accompli%$2 old indu/ries h be5 revolutioniz$1 & new indu/ries creat$4 ,! comm]cial _w ( to-day owes va/ debts to ! new sci5ce4 ,pr(essor ,*&l] outl9$ ! "* ( "o or two ( ^! 9 ! address j ref]r$ to4 ,he cit$ 9 "s detail1 = example1 ! diff]5ce betwe5 old me?ods & new 9 su* an indu/ry z ! manufacture ( cau/ic soda4 ,he pa9t$ a vivid ^w picture ( ! di/ress+ conditions "u :i* soda 0 produc$ 9 ! old-"t factories4 ,salt & sulphuric acid 7 comb9$ to produce sulphate ( soda1 :i* 0 mix$ ) lime & coal & heat$ 9 a rev]b]atory furnace4 ,ea* phase ( ! process 0 labori\s4 ,! workm5 op]at+ ! furnaces swelt]$ all day long 9 an almo/ unbe>able atmosph]e--/ripp$ to ! wai/1 dripp+ ) p]spiration1 sometimes ov]come ) heat4 ,_! task 0 "o ( ! mo/ try+ to :i* a man c\ld be subject$4 ,b to-day1 9 su* e/abli%m5ts z ! soda manufactories at ,niag>a ,falls1 all ?is is *ang$4 ,a salt solution circulates cont9u\sly 9 retorts :]e x c be act$ ^u by electricity suppli$ f dynamos op]at$ by ! wat]s ( ! ,niag>a ,riv]4 ,! workm51 com=tably dress$ & mov+ ab\t 9 a normal temp]ature1 h really no?+ to d b refill ! retorts n[ & !n & remove ! f9i%$ product4 ,x almo/ seems1 ,pr(essor ,*&l] add$ ) a smile1 z if workm5 ought to be glad to pay = ! privilege ( p>ticipat+ 9 s pleasant an occupation4 ,at all ev5ts x is1 9 all s]i\sness1 a pleasure = ! visitor :o kn[s no?+ ( old practices to witness ?is triumph ( a mod]n sci5tific me?od4 ,ev5 m int]e/+1 said ,pr(essor ,*&l]1 are ! processes employ$ 9 ! mod]n me?od ( produc+ ! metal alum9um by ! electrolytic process4 ,! process is bas$ on ! discov]y made by ,mr4 ,*>les ,m4 ,hall :ile he 0 a /ud5t work+ 9 a college laboratory1 t ! m9]al cryolite w absorb alum9a to ! ext5t ( tw5ty-five p] c5t4 ( its bulk1 z a sponge absorbs wat]4 ,! solution ( ?is comp\nd is !n act$ on by electricity1 & ! alum9um is deposit$ z pure metal4 ,a curi\sly int]e/+ practical detail ( ! process is bas$ on ! fact t pulv]iz$ coke rema9s p]fectly dry & rises to ! surface :5 /irr$ into a crucible conta9+ ! hot alum9a solution3 moreov]1 x rises to ! surface & rema9s !re z a %ield to protect ! workm5 aga9/ ! heat ( ! solution4 ,x s]ves yet ano!r purpose1 z ! p[d]$ alum9a may be sift$ ^u x & left !re to dry be=e be+ /irr$ into ! crucible4 ,a mo/ +5i\s yet simple device tells ! workman :5 any p>ticul> crucible is 9 ne$ ( repl5i%+4 ,a small1 ord9>y1 inc&esc5t electric-light bulb is plac$ 9 circuit betwe5 ! poles t convey ! electric curr5t ?r\gh ! alum9a solution4 ,s long z ! crucible conta9s alum9a1 ! bulb does n gl[1 because tw5ty volts ( electricity are requir$ to make x inc&esc5t1 :]eas sev5 volts pass ?r\gh ! solution4 ,b s soon z ! alum9a becomes exhau/$1 resi/ance to ! curr5t rises 9 ! cryolite solution &1 z x 71 dams back ! electric curr5t until x ov]fl[s into ! wire at suffici5t pressure to />t ! signal lamp4 ,!n x is necess>y m]ely = a workman to /ir into ! solution ! dry alum9a re/+ on ! surface1 along ) ! coke t supports x4 ,?is1 ( c\rse1 ree/abli%es ! electrolytic process2 ! lamp goes out & ! coke1 unaffect$ by its ba?1 rises to ! surface to support a fre% supply ( alum9a4 ,su* a process z ?is1 contra/$ ) ! usual me?ods ( smelt+ metals 9 fi]cely heat$ furnaces1 seems altoge!r wond]ful4 ,"h a pure metal is extract$ f ! clayey e>? ( :i* x =m$ a "p1 )\t be+ melt$ or subject$ to any ( ! famili> processes ( ! picturesque1 b co/ly1 labori\s1 & ev5 dang]\s1 bla/-furnaces4 ,!re is no gl>e & ro> ( fires2 !re are no %[]s ( sp>ks2 !re is no gu% ( fi]y /reams ( molt5 metal4 ,a sil5t & invisible electric curr5t1 g5]at$ by ! fall ( di/ant wat]s1 does ! "w m exp$iti\sly1 m effici5tly1 & m *eaply ?an x c\ld be done by any o!r me?od z yet discov]$4 ,fully to appreciate ! importance ( ! me?od j outl9$1 we mu/ reflect t alum9um is a metal comb9+ 9 "s measure ! prop]ties ( silv]1 copp]1 & iron4 ,x rivals copp] z a conductor ( electricity2 l silv] x is :ite 9 color & little subject to t>ni%+2 l iron x has great h>dness & t5sile /r5g?4 ,true1 x does n fully compete ) ! m famili> metals 9 _! respective fields2 b x comb9es _m valuable qualities 9 fair degree2 & x has an add$ prop]ty ( extreme lightness t is all its own4 ,add to ?is ! fact t alum9um is extremely abundant ev]y:]e 9 nature--x is a con/itu5t ( ne>ly all soils & is comput$ to =m ab\t ! twelf? "p ( ! entire cru/ ( ! e>?--:]eas ! o!r valuable metals are relatively r>e1 & x w appe> t alum9um mu/ be de/9$ to play an important "p 9 ! me*anics ( ! future4 ,!re is e indication t ! iron b$s w beg9 to give out at no immeasurably di/ant day2 b ! supply ( alum9um is absolutely inexhau/ible4 ,until n[ !re has be5 no means kn[n ( extract+ x *eaply f ! clay ( :i* x =ms s important a con/itu5t4 ,b at la/ electro-*emi/ry has solv$ ! problem2 & alum9um is sure to take an important place among ! indu/rial metals1 ev5 %\ld x fall %ort ( ! preem95t position z ! metal ( ! future t 0 once prematurely pr$ict$ = x4 ,,nitrog5 ,,f ,,! ,,air ,!re is a curi\s sugge/iv5ess ab\t ?is f9d+ ( alum9um at our v door1 s to speak1 "s scores ( c5turies aft] ! relatively r>e & inaccessible metals _h be5 kn[n & utiliz$ by man4 ,b !re is ano!r yet m /rik+ in/ance ( an abundant elem5t :i* man ne$$1 b knew n h[ to obta9 until ! sci5ce ( our own day solv$ ! problem ( mak+ x available4 ,?is is ! case ( ! nitrog5 ( ! air4 ,z e "o kn[s1 ?is gas =ms m ?an ?ree-f\r?s ( ! bulk ( ! atmosph]e4 ,b1 unlike ! o!r *ief con/itu5t1 oxyg51 x is n directly available = ! use ( plants & animals4 ,yet nitrog5 is an absolutely ess5tial con/itu5t ( ! tissues ( e liv+ organism1 vegetable & animal4 ,any liv+ ?+ f :i* x is )held mu/ die ( />vation1 ?\gh e o!r con/itu5t ( food be suppli$ )\t /9t2 & ! fact t ! />v+ organism is ba!d p]petually 9 an inexhau/ible sea ( atmosph]e *iefly compos$ ( nitrog5 w\ld n abate by "o jot ! c]ta9ty ( its doom4 ,to be made available z food = plants 7& ?us indirectly z food = animals7 nitrog5 mu/ be comb9$ ) "s o!r elem5t1 to =m a soluble salt4 ,b un=tunately ! atoms ( nitrog5 are v little prone to ent] into su* comb9ations2 "u all ord9>y conditions !y pref] a celibate exi/5ce4 ,9 e ?und]-/orm1 h[ev]1 a c]ta9 quantity ( nitrog5 is1 ?r\gh ! ag5cy ( lightn+1 made to comb9e ) ! hydrog5 ( dissociat$ wat]-vapor1 to =m ammonia2 & ?is ammonia1 wa%$ to ! e>? dissolv$ 9 ra9 drops1 w 9 due c\rse comb9e ) con/itu5ts ( ! soil & become available z plant food4 ,once made captive 9 ?is mann]1 ! nitrog5 atom may pass ?r\gh _m *anges & vicissitudes be=e x is aga9 fre$ & return$ to ! atmosph]e4 ,x may1 = example1 pass f ! tissues ( a plant to ! tissues ( a h]bivor\s animal & !nce to help make up ! sub/ance ( a c>nivor\s animal4 ,z animal excreta or z residue ( decay+ fle% x may return to ! soil1 to =m ! *ief con/itu5t ( a guano b$1 or ( a nitrate b$1--9 :i* latt] case x has comb9$ ) lime or sodium to =m a rocky /ratum ( ! e>?'s cru/ t may n be di/urb$ = untold ages4 ,a mom5t's reflection on ! conditions t gov]n vegetable & animal life 9 a /ate ( nature w make x cle> t a soil once suppli$ ) soluble nitrates is likely to be repl5i%$ almo/ p]petually ?r\gh ! decay ( vegetation4 ,b x is equally cle> t :5 ! same soil is till$ by man1 ! balance ( nature is likely to be at once di/urb$4 ,e p\nd ( gra9 or ( meat %ipp$ to a di/ant m>ket removes a portion ( nitrog52 & unless ! deficit is artificially suppli$1 ! soil becomes pres5tly impov]i%$4 ,b an artificial supply ( nitrog5 is n easily secur$--?\gh some?+ l tw5ty-five million tons ( pure nitrog5 are weigh+ d[n imp>tially ^u e squ>e mile ( ! e>?'s surface4 ,9 ! mid/ ( ?is tantaliz+ sea ( pl5ty1 ! f>m] has be5 oblig$ to take 8 *oice betwe5 see+ 8 l& become ye>ly m & m /]ile & s5d+ to f>-(f nitrate b$s = mat]ial to take ! place ( t remov$ by 8 successive crops4 ,! mo/ important ( ! nitrate b$s are situat$ 9 ,*ili1 & h be5 9 op]ation s9ce ! ye> #ahcj4 ,! draft ^u ^! b$s has increas$ enorm\sly 9 rec5t ye>s1 ) ! increas+ ne$s ( ! _w's population4 ,9 ! ye> #ahgj1 = example1 only #aej1jjj tons ( nitrate 7 %ipp$ f ! ,*ili b$s2 b 9 #ahij ! annual output _h gr[n to #hjj1jjj tons2 & x n[ exce$s a million & a half4 ,cons]vative e/imates pr$ict t at ! pres5t rate ( increas$ output ! entire supply w be exhau/$ 9 less ?an tw5ty ye>s4 ,& = "s ye>s back sci5ti/s & economi/s h be5 ask+ !mselves1 ,:at !n8 ,b n[ electro-*emi/ry has f\nd an answ]--ev5 :ile ! al>mi/s 7 pr$ict+ dire disa/]4 ,means h be5 f\nd to extract ! nitrog5 f ! atmosph]e1 9 a =m available z plant food1 & at a co/ t enables ! new syn!tic product to compete 9 ! m>ket ) ! ,*ili nitrate4 ,s all dang] ( a nitrog5 fam9e is n[ at an end1--& appli$ sci5ce has plac$ to its cr$it ano!r triumph1 second to none1 p]haps1 among all its conque/s4 ,! au?or ( ?is truly rem>kable feat is a ,sw$i% sci5ti/1 ,*ri/ian ,birkel& by "n1 ,pr(essor ( ,physics 9 ! ,univ]sity ( ,*ri/iania4 ,8 exp]im5ts 7 begun only ab\t ! ye> #aijc1 & ! practical ma*9]y = comm]cializ+ ! results--9 :i* ent]prise ,pr(essor ,birkel& has _h ! co-op]ation ( a practical eng9e]1 ,mr4 ,s4 ,eyde--is /ill 9 a s5se 9 ! exp]im5tal /age1--albeit a l>ge factory 0 put 9 successful op]ation 9 #aije at ,notodd51 ,norway4 ,pr(essor ,birkel& has ?us accompli%$ :at _m inve/igators 9 v>i\s p>ts ( ! _w h be5 /riv+ aft] = ye>s4 ,! significance ( 8 accompli%m5t consi/s 9 ! fact t he has demon/rat$ ! possibility ( mak+ nitrog5 comb9e ) oxyg5 9 l>ge quantities & at a relatively l[ exp5se4 ,! m]e fact ( ! comb9ation1 z a laboratory possibility1 _h be5 demon/rat$ 9 an eld] g5]ation by ,cav5di%1 & m rec5tly by su* work]s z ,sir ,william ,crookes1 & ,"l ,rayleigh 9 ,engl& & ,pr(essors ,w4 ,mutjmaan & ,h4 ,h(] 9 ,g]many4 ,moreov]1 ! exp]im5ts ( ,messrs4 ,bradley & ,lovejoy1 conduct$ on a comm]cial scale at ,niag>a ,falls1 _h seem$ to give promise ( a complete solution ( ! problem2 _h1 inde$1 produc$ a nitrog5 comp\nd f ! air 9 comm]cial quantity1 b n1 un=tunately1 at a co/ t made competition ) ! ,*ili nitrate possible4 ,equally unsuccessful 9 solv+ ?is important "p ( ! problem _h be5 ! exp]im5ts1 conduct$ on a l>ge scale1 ( ,pr(essors ,k[alski & ,moscicki1 at ,freiburg4 ,all ^! exp]im5t]s _h adopt$ ! same ag5t z ! means (1 s to say1 =c+ ! trans=mation--namely1 electricity4 ,! ,am]ican inve/igators employ$ a curr5t ( t5 ?\s& volts2 ! ,g]man work]s c>ri$ ! curr5t to fifty ?\s& volts4 ,! flame ( ! electric arc ?us produc$ ignit$ ! nitrog5 ) :i* x came 9 contact readily en\gh2 b ! difficulty 0 t x came 9 contact ) s little4 ,despite +5i\s arrangem5ts ( multiple poles1 ! burn+-surface ( ! multiple arc rema9$ s small 9 proportion to ! exp5diture ( en]gy t ! co/ ( ! op]ation f> exce$$ ! comm]cial value ( ! product4 ,su*1 at lea/1 mu/ be ! inf]5ce f ! fact t ! e/abli%m5ts 9 "q did n atta9 comm]cial success4 ,! peculi>ity ( ,pr(essor ,birkel&'s me?od is bas$ ^u ! curi\s fact t :5 ! electric arc is made to pass ?r\gh a magnetic field1 its l9e ( flame spreads out into a l>ge disk--l a flam+ sun4 ,! %eet ( flame ?us produc$ repres5ts no great] exp5diture ( en]gy ?an ! lightn+ fla% ( light t ! same curr5t w\ld produce outside ! magnetic field2 b x obvi\sly adds enorm\sly to ! arc-light surface t comes 9 contact ) ! air1 & h5ce 9 l proportion to ! am\nt ( nitrog5 t w be ignit$4 ,9 po9t ( fact1 ?is burn+ ( nitrog5 takes place s rapidly 9 laboratory exp]im5ts z to vitiate ! air ( ! room v quickly4 ,9 ! comm]cial op]ation1 ) p[]ful electro-magnets & a curr5t ( five ?\s& volts1 op]at+1 ( c\rse1 9 clos$ *amb]s1 ! ratio betwe5 en]gy exp5d$ & result a*iev$ is highly satisfactory f a bus9ess /&po9t1 & w d\btless become /ill m s z ! app>atus is fur!r p]fect$4 ,to ! casual read]1 unaccu/om$ to *emical me?ods1 !re may seem a puzzle 9 ! explanation j outl9$4 ,he may be dispos$ to say1 ,y speak ( ! nitrog5 z be+ ignit$ & burn$2 b if x is burn$ & ?us consum$1 h[ c x be ( s]vice8 ,su* a ?\ght is natural en\gh to "o :o ?9ks ( burn+ z appli$ to ord9>y fuel1 :i* seems to disappe> :5 x is burn$4 ,b1 ( c\rse1 ev5 ! tyro 9 *emi/ry kn[s t ! fuel has n really disappe>$ except 9 a v crude visual s5se2 x has m]ely *ang$ its =m4 ,9 ! ma9 its solid sub/ance has become gase\s1 b e atom ( x is /ill j z real1 if n q s tangible1 z be=e2 & ! *emi/ c\ld1 "u prop] conditions1 collect & weigh & measure ! trans=m$ gases1 & ev5 retrans=m !m into solids4 ,9 ! case ( ! atmosph]ic nitrog51 z 9 ! case ( ord9>y fuel1 a burn+ consi/s ess5tially 9 ! union ( nitrog5 atoms ) atoms ( oxyg54 ,! prov9ce ( ! electric curr5t is to produce ! high temp]ature at :i* alone su* union w take place4 ,! portion ( nitrog5 t has be5 ?us burn$ is /ill gase\s1 b is no long] 9 ! /ate ( pure nitrog52 its atoms are unit$ ) oxyg5 atoms to =m nitr\s oxide gas4 ,?is gas1 mix$ ) ! atmosph]e 9 :i* x has be5 g5]at$1 may n[ be pass$ ?r\gh a res]voir ( wat]1 & ! new gas comb9es ) a portion ( wat] to =m nitric acid1 ea* molecule ( :i* is a comp\nd ( "o atom ( hydrog51 "o atom ( nitrog51 & ?ree atoms ( oxyg52 & nitric acid1 z ev]yone kn[s1 is a v active sub/ance1 z m>k$ 9 its eag]ness to unite ) o!r sub/ances z pure nitrog5 is 9 its alo(ness4 ,9 ! comm]cial nitrog5-plant at ,notodd51 ! trans=m$ nitrog5 comp\nd is br\ght into contact ) a solution ( milk ( lime1 ) ! result+ =mation ( nitrate ( lime 7calcium nitrate71 a sub/ance id5tical 9 composition--except t x is ( great] purity--) ! product ( ! nitrate b$s ( ,*ili4 ,/or$ 9 clos$ cans z a milky fluid1 ! trans=m$ atmosph]e is n[ ready = ! m>ket4 ,a c]ta9 am\nt ( x w be us$ 9 o!r manufactories = ! production ( v>i\s nitrog5\s *emicals2 b ! bulk ( x w be %ipp$ to agricultural di/ricts to be spread ov] ! soil z f]tiliz]1 & 9 due c\rse to be absorb$ into ! tissues ( plants to =m ! food ( animals & man4 ,,ano!r ,,me?od ,,( ,,nitrog5 ,,fixation ,j at ! "t :5 ! ,sc&9avian exp]im5t]s 7 solv+ ! problem ( secur+ nitrog5 f ! air1 o!r exp]im5t]s 9 ,italy1 op]at+ along totally diff]5t l9es1 rea*$ ! same important result4 ,! process employ$ by ^! inve/igators is kn[n z ! ,frank & ,c>o process1 & x bids fair to rival ! ,norwegian me?od z a comm]cial ent]prise4 ,! process is describ$ z foll[s by an eng9e]+ correspond5t ( ! ,london ,times 9 ! ,eng9e]+ ,supplem5t ( t p]iodical = ,janu>y #bb1 #aijh3 ,?is process is bas$ ^u ! absorption ( nitrog5 by calcium c>bide1 :5 ?is gas1 9 ! pure =m1 is pass$ ov] ! c>bide heat$ to a temp]ature ( #a1ajj degrees c5tigrade 9 retorts ( special =m & design4 ,! calcium c>bide requir$ z raw mat]ial = ! cyanamide manufacture is produc$ 9 ! usual mann] by heat+ lime & coke to a temp]ature ( #b1ejj degrees c5tigrade 9 electric furnaces ( ! resi/ance type4 ,! ,european pat5t rights ( ! ,frank & ,c>o process h be5 pur*as$ by ! ,societa ,g5]ale p] la ,cianamide ( ,rome1 & ! v>i\s subsidi>y companies promot+ ! manufacture 9 ,italy1 ,france1 ,switz]l&1 ,norway1 & else:]e1 are work+ "u arrangem5t ) ! p>5t company z reg>ds %>+ ( pr(its4 ,! fir/ l>ge in/allation ( a plant = c>ry+ out ?is process 0 erect$ at ,piano d',orta1 9 ,c5tral ,italy1 & 0 put into op]ation 9 ,decemb]1 #aije4 ,! p[] = ?is factory is develop$ by an indep5d5t company1 & is obta9$ by tak+ wat] f ! riv] ,pesc>a & lead+ x to a po9t above ! g5]at+ /ation at ,tramonti4 ,a head ( #ij feet1 equival5t to #h1djj horse-p[]1 is "h made available = ! indu/ries ( ! di/rict4 ,! p[] ( ! cyanamide factory is transmitt$ a di/ance ( #f-a_/d miles at #f1jjj volts4 ,an alum9um & *emical works are also dep5d5t ^u ! same p[] /ation4 ,! ,piano d',orta works conta9s six furnaces = ! manufacture ( cyanamide1 ea* furnace conta9+ five retorts = absorption ( ! nitrog5 by ! c>bide4 ,a retort is capable ( work+ (f ?ree *>ges ( #ajj kilograms 7#bbj p\nds7 ( c>bide p] day ( #bd h\rs1 ! weight ( ! *>ge increas+ to #abe kilograms by ! nitrog5 absorb$4 ,! pres5t c>bide consumption ( ! ,piano d',orta factory is1 !re=e1 at ! rate ( ab\t #c1jjj tons p] annum1 & ! output ( calcium cyanamide is ab\t #c1gej tons p] annum4 ,! company controll+ ! manufacture at ,piano d',orta is nam$ ! ,societa ,italiana p] la ,fabbricazione di ,prodotti ,azotati4 ,ext5sions ( ! factory at ?is place to a capacity ( #aj1jjj tons p] annum are already 9 progress4 ,ano!r company is also plann+ ! erection ( simil> works at ,fiume & at ,seb5ico1 on ! ea/]n bord]s ( ! ,adriatic ,sea4 ,! additional electric p[] requir$ w be obta9$ by c>ry+ out ! second portion ( ! p[] developm5t s*eme on ! riv] ,pesc>a4 ,a fall ( #bce feet1 equival5t to #bb1jjj horse-p[]1 is available at ! new p[] /ation1 :i* is be+ erect$ at ,piano d',orta4 ,aft] /at+ t companies to op]ate ! ,frank & ,c>o process h be5 organiz$ 9 ,france1 9 ,switz]l&1 9 ,g]many1 9 ,engl&1 & 9 ,am]ica1--! la/-nam$ plant be+ at ,muscle ,%oals1 ,t5nessee ,riv]1 9 ,nor!rn ,alabama--! writ] cont9ues3 ,^! facts prove t ! manufacture ( ! new nitrog5\s manure w soon be c>ri$ on 9 all ! m important c\ntries on bo? sides ( ! ,atlantic4 ,if ! f9ancial results come up to ! promot]'s expectations ! indu/ry 9 five ye>s' "t w h become "o ( consid]able magnitude4 ,a modification ( ! orig9al process ( "s importance has be5 sugge/$ by ,polz5iusz4 ,?is *emi/ has f\nd t ! addition ( fluorsp> 7,ca,f#b7 to ! c>bide r$uces ! temp]ature requir$ = ! absorption process by #djj degrees c5tigrade1 :ile x also produces a less deliquesc5t f9i%$ mat]ial4 ,z reg>ds co/ ( manufacture1 no v reliable figures are yet available1 b ! companies promot+ ! new manufacture are regulat+ _! sale prices by ^? ( ! two rival artificial manures--ammonium sulphate & nitrate ( soda4 ,calcium cyanamide is n[ be+ sold 9 ,g]many at #as4 to #as4 #f;d4 7#be to #cg c5ts7 p] unit ( comb9$ nitrog5 *eap] ?an ammonium sulphate1 & #cs4 to #cs4 #f;d4 7#ge to #hg c5ts7 p] unit *eap] ?an nitrate ( soda4 ,:e!r ! manufacture w prove remun]ative at ?is price ( ab\t #aj #ajs4 7#ajb4ej7 p] ton rema9s to be se54 ,x is evid5t t1 z ! raw mat]ial ( ! cyanamide manufacture 7calcium c>bide7 co/s at lea/ #h 7#dj7 p] ton to produce "u ! mo/ favorable conditions1 ! m>g9 ( pr(it w n be l>ge1 & t v effici5t managem5t w be requir$ to e>n fair divid5ds on ! capital sunk 9 ! new indu/ry4 ,x mu/ be not$1 h[ev]1 t ! processes are new & are d\btless capable ( improvem5t z exp]i5ce is ga9$ 9 work+ !m2 :ile1 on ! o!r h&1 ! competition ( ! two rival artificial manures is likely to dim9i% z ! ye>s pass on4 ,! new indu/ry is1 !re=e1 likely to be a p]man5t addition to ! li/ ( electro-metallurgical processes4 ,b = ! pres5t its success c only be expect$ 9 c5tres ( v *eap wat]-p[]1 z1 = in/ance1 9 ^? localities :]e ! electric horse-p[] ye> c be g5]at$ & transmitt$ to ! cyanamide works at an inclusive co/ ( #b 7#aj7 or "u4 ,,electrical ,,en]gy ,,& ,,high ,,temp]atures ,x w be obs]v$ t ! active in/rum5tality by :i* ! indu/rial feats ?us f> outl9$ h be5 accompli%$1 is t weird convey] ( en]gy kn[n z electricity4 ,9 ! case ( ! alum9um manufacture1 electricity op]at$ accord+ to ! /range process ( electrolysis1 9 virtue ( :i* c]ta9 atoms ( matt] move to "o pole ( a batt]y :ile o!r atoms move to ! opposite pole1 ?us effect+ a sep>ation--! result be+1 9 ! case 9 "q1 ! deposit ( pure alum9um at ! negative pole4 ,9 ! case ( ! nitrog5 factories1 h[ev]1 ! mann] ( op]ation ( ! electric curr5t is q diff]5t4 ,electricity1 z su*1 is n really conc]n$ 9 ! matt]2 ! effici5cy ( ! curr5t dep5ds solely ^u ! production ( heat4 ,= example1 any o!r ag5cy t br\ght ! atmosph]e to a correspond+ temp]ature w\ld be equally efficaci\s 9 ignit+ ! nitrog54 ,b 9 actual practice1 = ?is p>ticul> purpose1 no o!r kn[n means ( produc+ high temp]atures c\ld at all compete ) ! electric arc4 ,!re are num]\s o!r op]ations involv+ ! employm5t ( high temp]atures 9 :i* electricity is equally preem95t4 ,x is feasible ) ! electric arc to atta9 a temp]ature ( ab\t #c1fjj degrees c5tigrade--& ev5 ?is might be exce$$ 7 x n t c>bon1 ( :i* ! electrodes are compos$1 volatilizes at t temp]ature4 ,meantime1 ! highe/ atta9able temp]ature ) ord9>y fuels 9 ! bla/ furnace is only ab\t #a1hjj degrees2 & ! oxy-hydrog5 flame is only ab\t two hundr$ degrees high]4 ,a mixture ( oxyg5 & acetyl5e1 h[ev]1 burns at a temp]ature almo/ equal+ t ( ! electric arc2 & ?is flame1 manipulat$ ) ! aid ( a bl[pipe1 (f]s a useful means ( apply+ a high temp]ature locally1 = su* processes z ! weld+ ( metals4 ,! v highe/ temp]atures yet rea*$ 9 laboratory or work%op1 h[ev]1 are due to ! use ( explosive mixtures4 ,?us a mixture ( ! metal alum9um granulat$1 & oxide ( iron1 :5 ignit$ by a fulm9at+ p[d]1 readju/s its atoms to =m oxide ( alum9um & pure iron1 & does ?is ) su* f]vor t a temp]ature ( ab\t ?ree ?\s& degrees is rea*$1 ! result+ iron be+ n m]ely melt$ b br\ght almo/ to ! boil+ po9t4 ,practical advantage is tak5 ( ?is reaction = ! repair ( brok5 implem5ts ( iron or /eel1 ! mak+ ( cont9u\s rails = trolleys1 & ! l4 ,?is reaction ( alum9um & iron does n1 to be sure1 give a high] temp]ature ?an ! electric arc2 b ?is culm9at+ feat has be5 a*iev$1 9 laboratory exp]im5ts1 ?r\gh ! explosion ( cordite 9 clos$ /eel *amb]s2 ! exp]im5t]s be+ ! ,engli%m5 ,sir ,&rew ,noble & ,sir ,f4 ,abel4 ,x is difficult to e/imate accurately ! degree ( heat & pressure atta9$ 9 ^! exp]im5ts2 b x is believ$ t ! temp]ature approximat$ #e1jjj degrees c5tigrade1 :ile ! pressure repres5t$ ! almo/ inconceivable pu% ( n9ety tons to ! squ>e in*4 ,x may be ( int]e/ to expla9 t cordite is a =m ( smokeless p[d] compos$ ( gun cotton1 nitroglyc]9e1 & m9]al jelly4 ,no d\bt ! extreme heat produc$ by its explosion is associat$ ) ! sudd5ness ( ! reaction2 correspond+ to ! effici5cy z a propellant t has l$ to ! adoption ( ?is p[d] = use 9 ! small arms ( ! ,briti% ,army4 ,no comm]cial use has yet be5 made ( cordite z a m]e produc] ( heat2 b !re is an int]e/+ sugge/ion ( possible future uses 9 ! fact t cry/als ( diamond h be5 f\nd 9 ! residue ( ! explosion *amb]--microscopic 9 size1 to be sure1 b v]itable diamonds 9 m9iature4 ,sir ,william ,crookes has sugge/$ t1 c\ld ! reaction be prolong$ suffici5tly1 !re is little d\bt t ! artificial =mation ( diamonds w\ld soon pass f ! microscopic /age to a scale m likely to satisfy ! requirem5ts ( sci5ce1 if n ^? ( p]sonal adornm5t4 ,,o!r ,,indu/rial ,,problems ,,( ,,to-,,day ,,& ,,to-,,morr[ ,9 attempt+ to sugge/ ! importance ( sci5ce 9 its relation to mod]n indu/ries1 ,i h ?\ght x bett] to cite ?ree or f\r illu/rative cases 9 "s detail r ?an to attempt a compreh5sive summ>y ( ! almo/ numb]less l9es ( comm]cial activity t h a simil> orig9 & dep5d5ce4 ,to attempt a full li/ ( ^! w\ld be virtually to give a catalogue ( me*anical indu/ries4 ,x may be well1 h[ev]1 to po9t out a few famili> in/ances1 9 ord] to emphasize ! economic importance ( ! subject2 & to sugge/ a few ( ! l9es along :i* pres5t-day inve/igators are seek+ fur!r conque/s4 ,v briefly1 !n1 consid] h[ ! application ( sci5tific k has *ang$ ! aspect ( ! productive indu/ries4 ,?anks to sci5ce1 f>m+ is no long] a haphaz>d trade4 ,! up-to-date f>m] kn[s ! *emical con/itution ( ! soil2 und]/&s :at con/itu5ts are ne$$ by p>ticul> crops & :at f]tiliz+ me?ods to employ to keep 8 l& f det]iorat+4 ,he kn[s h[ to select good se$ accord+ to ! tea*+ ( h]$ity2 h[ to combat fungoid & insect pe/s by *emical means2 h[ to meet ! encroa*m5ts ( ! army ( we$s4 ,9 ! or*>d1 he c tell by ! appe>ance ( leaf & b>k :e!r ! soil ne$s m ( nitrog51 ( pota%1 or ( humus2 he uses sprays z a surgeon uses antiseptics2 he introduces fri5dly insects to prey on insect pe/s2 he irrigates or surface-tills or gr[s cov] crops 9 accordance ) a good und]/&+ ( ! laws ( capill>ity z appli$ to wat] 9 ! e>?'s cru/4 ,9 b>ny>d & dairy he applies a k ( ! *emi/ry ( foods 9 8 treatm5t ( flock & h]d2 he v5tilates 8 /ables t ! /ock may h an adequate supply ( oxyg52 he milks 8 c[s ) a me*anical app>atus1 extracts ! cream ) a c5trifugal sep>ator1 & *urns by /eam or by electric p[]4 ,9 ! affairs ( manufactur] & transport] ( commodities1 me?ods are no less revolution>y4 ,/eam p[] & electric dynamo ev]y:]e hold sway2 trolley & electric light & telephone h f\nd _! way to ! mo/ di/ant hamlet2 electricians & exp]im5tal *emi/s are se>*+ = new me?ods 9 ! factories2 artificial /one is compet+ ) ! product ( ! qu>ries2 artificial dyes h s\nd$ ! doom ( ! madd] & indigo indu/ries4 ,& yet x requires no great gift ( prophecy to see t :at has be5 accompli%$ is only an e>ne/ ( :at is to come 9 ! n di/ant future4 ,9 e direction eag] exp]im5t]s are on ! track ( new discov]ies4 ,any day a *ance obs]vation may op5 new & important fields ( exploration1 j z ,hall's obs]vation ab\t ! p[] ( cryolite to absorb alum9um po9t$ ! way to ! new alum9um indu/ry2 & z ,birkel&'s *ance obs]vation ( ! electric arc 9 a magnetic field unlock$ ! secret ( ! unresponsive nitrog54 ,x w probably n be long1 = example1 be=e a way w be f\nd to produce electric light )\t heat--9 imitation ( ! wond]ful lamp ( ! gl[-worm4 ,!n 9 due c\rse we mu/ le>n to use fuel )\t ! appall+ wa/e t at pres5t seems unavoidable4 ,a mod]n /eam-eng9e makes available only five to t5 p] c5t4 ( ! en]gy t ! burn+ fuel gives out z heat--! re/ is dissipat$ )\t s]v+ man ! slighte/ useful purpose4 ,moreov]1 ! new /udies 9 radio-activity h taught u t e molecule ( matt] locks up among its :irl+ atoms & corpuscles a /ore ( en]gy comp>$ ) :i* ! en]gy ( heat is b a bagatelle4 ,x is e/imat$ t a little pea-siz$ fragm5t ( radium has en]gy en\gh 9 /ore--c\ld we b le>n to use x--to drive ! l>ge/ /eam%ip across ! ocean--tak+ ! place ( hundr$s ( tons ( coal z n[ employ$4 ,! me*anics ( ! future mu/ le>n h[ to unlock ?is treasury ( ! molecule2 h[ to get at ^! atomic & corpuscul> =ces1 ! v exi/5ce ( :i* 0 unkn[n to sci5ce until ye/]day4 ,! g5]ation t has le>n$ t secret w look back ^u ! fuel problems ( our day some:at z we reg>d ! fl9t & /eel & ! op5 fire ( ! b>b>ian4 ,if problems ( en]gy (f] su* allur+ possibilities z ?is1 problems ( matt] are ev5 m inspir+4 ,! new syn!tic *emi/ry sets no b\nds to its ambitions4 ,x has succe$$ 9 manufactur+ madd]1 indigo1 & a multitude ( m9or comp\nds4 ,x hopes "s day to manufacture rubb]1 />*1 sug>--ev5 album5 itself1 ! v basis ( life4 ,rubb] is a relatively simple comp\nd ( hydrog5 & c>bon2 />* & sug> are compos$ ( hydrog51 c>bon1 & oxyg52 album5 has ! same con/itu5ts1 plus nitrog54 ,! raw mat]ials = build+ up ^! sub/ances lie ev]y:]e ab\t u 9 abundance4 ,a lump ( coal1 a glass ( wat]1 & a :iff ( atmosph]e conta9 all ! nutritive elem5ts1 c\ld we prop]ly mix !m1 ( a loaf ( bread or a beef/eak4 ,& sci5ce w nev] re/ cont5t until x has le>n$ h[ to make ! comb9ation4 ,x is a long road to travel1 ev5 f ! relatively advanc$ /&po9t ( to-day2 b soon] or lat] sci5ce w surely travel x4 ,& !n--:o c imag9e1 :o d>e pr$ict1 ! social & economic revolution t mu/ foll[8 ,our social & bus9ess life to-day diff]s m widely f t ( our gr&fa!rs ?an !irs diff]$ f ! life ( ! ,egyptian & ,babylonian ( ?ree ?\s& ye>s ago2 b ?is gap is z dit* to caon comp>$ ) ! gap t sep>ates u f ! life ( t g5]ation ( our desc5dants :i* %all h le>n$ ! secret ( mak+ food-/uffs f inorganic matt] 9 ! laboratory & factory4 ,x is a long road to travel1 ,i repeat2 b mod]n sci5ce travels swiftly & ) _m %ort-cuts1 & x may rea* ?is goal m quickly ?an any cons]vative dream] ( to-day w\ld d>e to pr$ict4 ,all spe$ to ! ambiti\s voyag]6 ,,app5dix ,,ref]5ce ,,li/ ,,& ,,notes ,,*apt] ,i ,,man ,,& ,,nature ,= a g5]al discussion ( primitive conditions ( labor & prehi/oric man's civilization1 x w be ( int]e/ 9 connection ) ?is *apt] to consult volume ,i41 *apt] ,i41 :i* deals ) prehi/oric sci5ce4 ,! app5dix notes on t *apt] 7vol4 ,i41 pp4 #cjb1 #cjc7 ref] to "s books :i* may be consult$ = full] in=mation along ! same l9es4 ,,*apt] ,,ii ,,h[ ,,"w ,,is ,,done 7p4 #ca74 ,= /udy ( ,ar*im$es1 giv+ a detail$ acc\nt ( 8 discov]ies1 see vol4 ,i41 p4 #aif seq4 ,x w be ( int]e/ also to review1 9 connection ) ?is *apt]1 ! /ory ( ! gr[? ( k ( me*anics 9 ! "t ( ,galileo1 ,desc>tes1 & ,newton z told 9 ! *apt]s entitl$ ,galileo & ! ,new ,physics1 vol4 ,,ii4 7p4 #ic seq471 & ,! ,success ( ,galileo 9 ,physical ,sci5ce1 vol4 ,,ii41 p4 #bjd seq4 ,,*apt] ,,iii ,,! ,,animal ,,ma*9e ,= fur!r insight into ! activities ( ! animal ma*9e1 ! read] may ref] to v>i\s *apt]s on ! progress ( physiology & anatomy 9 e>li] volumes4 ,! foll[+ ref]5ces w guide to ! acc\nts ( ! successive advances f ! e>lie/ "t3 ,vol4 ,i41 pp4 #aid1 #aie describe briefly ! e>li] anatomical /udies ( ! ,alex&rian physicians1 ,h]ophilus & ,erasi/ratus2 & pp4 #bhb1 #bhc1 outl9e ! /udies ( ! fam\s physician1 ,gal54 ,vol4 ,,ii41 ,f ,p>acelsus to ,h>vey1 9 p>ticul>1 p4 #afc seq42 & *apt]s ,,iv4 7p4 #agc seq47 & ,v4 7p4 #bjb seq47 deal+ ) ! progress ( anatomy & physiology 9 ! eighte5? & n9ete5? c5turies respectively4 ,! *apt] on ,exp]im5tal ,psy*ology 7p4 #bde seq47 may also be consult$4 ,vol4 ,v41 *apt] ,v41 deal+ ) ! ,m>9e ,biological ,laboratory at ,naples 7p4 #aac seq47 & *apt] ,,vi41 ,ern/ ,haeckel & ! ,new ,zoology 7p4 #add seq47 pres5t o!r aspects ( physiological problems4 ,,*apt] ,,iv ,,! ,,"w ,,( ,,air ,,& ,,wat] ,on page #fc ref]5ce is made to ! "w ( ! old ,greeks1 ,ar*im$es & ,ctesibius4 ,an acc\nt ( ,ar*im$es' discov]y ( ! laws ( buoyancy ( solids & liquids w be f\nd 9 vol4 ,i41 p4 #bjh4 7p4 #fd74 ,! ma*9es ( ,ctesibius & ,h]o4 ,see vol4 ,i41 p4 #bdb seq41 = a full acc\nt ( ^! me*anisms4 7p4 #fe74 ,toricelli1 ! pupil ( ,galileo1 & 8 discov]y ( atmosph]ic pressure4 ,= a full] acc\nt ( 8 discov]y & :at came ( x see vol4 ,,ii41 p4 #abj seq4 7p4 #ff74 ,boyle's exp]im5ts on atmosph]ic pressure4 ,see vol4 ,,ii41 p4 #bjd seq4 7p4 #ff74 ,m>iotte & ,von ,gu]icke4 ,see vol4 ,,ii41 p4 #baj seq4 7p4 #ga74 ,roman mills4 ,a s*ol>ly discussion ( ! subject ( ,roman mills1 bas$ on a compreh5sive /udy ( ! ref]5ces 9 classical lit]ature1 is giv5 9 ,beckmann's ,hi/ory ( ,inv5tions1 ,london1 #ahdf4 7p4 #gc74 ,rec5t advances 9 wat] :eels4 ,z /at$ 9 ! text1 ! quotation is f an article on ,motive ,p[] ,appliances1 by ,mr4 ,edw>d ,h4 ,sanborn1 9 ! ,twelf? ,c5sus ,report ( ! ,unit$ ,/ates4 ,,*apt] ,v ,,captive ,,molecules2 ,,! ,,/ory ,,( ,,! ,,/eam-,,eng9e 7p4 #hb74 ,! exp]im5ts ( ,h]o ( ,alex&ria4 ,= a full acc\nt ( ! exp]im5ts see vol4 ,i41 pp4 #bdi1 #bej4 7p4 #hd74 ,! ,m>quis ( ,worce/]'s /eam eng9e4 ,! orig9al acc\nt appe>$1 z /at$1 9 ! ,m>quis ( ,worce/]'s ,c5tury ( ,inv5tions1 publi%$ 9 #affc4 7p4 #ib74 ,newcom5's eng9e4 ,z /at$ 9 ! text1 ! acc\nt ( ,newcom5's eng9e is quot$ f ! report ( ! ,dep>tm5t ( ,sci5ce & ,arts ( ! ,s\? ,k5s+ton ,museum1 n[ (ficially kn[n z ! ,victoria & ,alb]t ,museum4 7pp4 #ajg-aji74 ,james ,watt4 ,! *>act]ization ( ,watt "h giv5 is tak5 f an article 9 an e>ly edition ( ! ,ed9burgh ,encyclopdia publi%$ ab\t ! ye> #ahae4 ,,*apt] ,,vi ,,! ,,ma/] ,,work] 7p4 #aab74 ,high-pressure /eam4 ,! "w ref]r$ to is ,leupold's ,!atrum ,ma*9>um1 #agbe4 7p4 #abb74 ,rot>y ,eng9es4 ,! quotation is f ! report ( ! ,victoria & ,alb]t ,museum above cit$4 7pp4 #abg1 #abh74 ,turb9e eng9es4 ,! quotation is f an anonym\s article 9 ! ,london ,times1 ,augu/ #ad1 #aijg4 7pp4 #abi1 #acj74 ,turb9e eng9es4 ,! quotation is f an article on ,motive ,p[] ,appliances 9 ! ,twelf? ,c5sus ,report ( ! ,unit$ ,/ates1 vol4 ,x41 "p ,,iv41 by ,mr4 ,edw>d ,h4 ,sanborn4 ,,*apt] ,,vii ,,gas ,,& ,,oil ,,eng9es 7pp4 #ace1 #acf1 #acg74 ,gas eng9es4 ,quot$ f ! report ( ! ,victoria & ,alb]t ,museum above cit$4 7pp4 #ada-add74 ,gas eng9es & /eam eng9es 9 ! ,unit$ ,/ates4 ,quot$ f ! report ( ! ,special ,ag5ts ( ! ,twelf? ,c5sus ( ! ,unit$ ,/ates1 #aijb4 7pp4 #adf1 #adg74 ,! ,svea heat]4 ,f an article by ,mr4 ,g4 ,emil ,hesse 9 ,! ,am]ican ,inv5tor = ,april #ae1 #aije4 ,,*apt] ,,viii ,,! ,,smalle/ ,,work]s ,9 connection ) ?is *apt] ! read] w d well to review v>i\s e>li] portions ( ! "w outl9+ ! g5]al hi/ory ( ! gr[? ( k ( electricity & magnetism4 ,= example3 ,vol4 ,,ii41 p4 #aaa seq41 = an acc\nt ( ,william ,gilb]t's /udy ( magnetism2 pp4 #bac1 #bae describ+ fir/ electrical ma*9e2 & *apt] ,,xiv41 ,! ,progress ( ,electricity f ,gilb]t & ,von ,gu]icke to ,frankl91 p4 #bei seq4 ,vol4 ,,iii41 *apt] ,,vii41 ,! ,mod]n ,developm5t ( ,electricity & ,magnetism1 p4 #bbi seq4 ,vol4 ,v41 p4 #ib seq41 ! section on ,pr(4 ,j4 ,j4 ,?ompson & ! nature ( electricity4 ,o!r *apt]s t may be advantage\sly review$ 9 connection ) ! pres5t "o are ! foll[+3 ,vol4 ,,iii41 *apt] ,,vi41 ,mod]n ,!ories ( ,heat & ,light1 p4 #bjf seq42 *apt] ,,viii41 ,! ,cons]vation ( ,en]gy1 p4 #bec seq42 & *apt] ,,ix41 ,! ,e!r & ,pond]able ,matt]1 p4 #bhc seq4 ,,*apt] ,,ix ,,man',s ,,newe/ ,,co-,,labor]3 ,,! ,,dynamo ,! ref]5ces j giv5 = *apt] ,,viii4 apply equally "h4 ,! exp]im5ts ( ,o]/$ & ,f>aday are detail$ 9 vol4 ,,iii41 p4 #bcf seq4 ,,*apt] ,x ,,niag>a ,,9 ,,h>ness ,same ref]5ces z = *apt]s ,,viii4 & ,,ix4 ,,*apt] ,,xi ,,! ,,bani%m5t ,,( ,,night 7p4 #bba74 ,davy & ! electric light4 ,! quotation "h giv5 is reproduc$ f vol4 ,,iii41 pp4 #bcd1 #bce4 ,! v great importance & g5]al int]e/ ( ! subject seem to ju/ify ! repetition1 descriptive ( ?is fir/ electric light4 ,davy's orig9al pap] 0 giv5 at ! ,royal ,in/itution 9 #ahaj4 7p4 #bcg74 ,pet] ,coop] ,hewitt--,inv5tor1 by ,ray ,/ann>d ,bak]1 9 ,mc,clure's ,magaz9e1 ,june1 #aijc1 p4 #agb4 ,9 connection ) ! problem ( color ( ! light emitt$ by ,mr4 ,hewitt's m]cury-vapor tube1 ! *apt] on ,newton & ! ,composition ( ,light 7vol4 ,,ii41 p4 #bbe seq47 may be consult$4 ,also ,mod]n ,!ories ( ,heat & ,light1 vol4 ,,iii41 p4 #bjf seq4 ,,*apt] ,,xii ,,! ,,m9]al ,,dep?s ,! *apt] on ,! ,orig9 & ,developm5t ( ,mod]n ,geology1 vol4 ,,iii41 p4 #aaf seq41 may be read 9 connection ) ! alli$ subjects "h treat$4 ,9 prep>+ ! section on ! use ( electricity 9 m9+1 ! article by ,?omas ,comm]=d ,m>t91 entitl$ ,electricity 9 ,m9+1 9 ! ,unit$ ,/ates ,c5sus ,report ( #aije1 has be5 freely drawn ^u4 ,! quotations on pp4 #bfb1 #bff1 #bfh1 & #bgj are f t s\rce4 ,,*apt] ,,xiii ,,! ,,age ,,( ,,/eel ,see note "u *apt] ,,xii4 ,,*apt] ,,xiv ,,"s ,,rec5t ,,triumphs ,,( ,,appli$ ,,sci5ce ,9 connection ) v>i\s portions ( ?is *apt] ! read] w f9d mu* t is ( int]e/ 9 ! /ory ( *emical developm5t 9 g5]al z detail$ 9 volume ,,iii41 pp4 #c-gb inclusive4 ,also v>i\s *apt]s on electricity z outl9$ "u *apt] ,,vii4 above4 7p4 #caj74 ,nitrog5 f ! air4 ,! quotation is f ! ,eng9e]+ ,supplem5t ( ! ,london ,times1 ,janu>y #bb1 #aijh4 ,,transcrib]',s ,,notes ,italic text is d5ot$ by und]scores4 ,! oe ligature has be5 exp&$ to 'oe'4 ,subscripts 9 *emical =mulas are d5ot$ by normal numb]s2 = example ,ca,c#b4 ,obvi\s typographical & punctuation errors h be5 correct$ aft] c>eful comp>ison ) o!r occurr5ces )9 ! text & consultation ( ext]nal s\rces4 ,except = ^? *anges not$ bel[1 inconsi/5t or ar*aic spell+ ( a ^w or ^w-pair )9 ! text has be5 reta9$4 ,= example3 horse%oe horse-%oe2 sup]heat$ sup]-heat$2 intru/$2 incas$4 p iii4 ',friction1 p4 #ce' *ang$ to ',friction1 p4 #ci'4 p iii4 'muscul> action1 p4 #de' *ang$ to '444 action1 p4 #di'4 p iv4 'w9d-mill' *ang$ to 'w9dmill'4 p iv4 ',ctesibus' *ang$ to ',ctesibius'4 p #ic4 '0 done is' *ang$ to '0 done 9'4 p #aad 7,illu/ration caption74 ',treve?ick' *ang$ to ',trevi?ick'4 p #abb4 'drlv+' *ang$ to 'driv+'4 p #ahj 7,illu/ration caption74 'pull pieces' left un*ang$ 7probably meant to be 'pole pieces'74 p #aia4 ',horsehoe' *ang$ to ',horse%oe'4 p #bfd4 ',lige' *ang$ to ',lige'4 p #bii4 'repellant' *ang$ to 'repell5t'4