,transcrib]'s ,notes ,small capitals h be5 transcrib$ z ,,all ,,capitals2 text 9 italics has be5 transcrib$ betwe5 und]scores1 z text4 ,! symbol is us$ to repres5t an upside-d[n ,u4 ,m ,transcrib]'s ,notes may be f\nd at ! end ( ?is text4 ,publi%$ by ! ,mc,graw-,hill ,book ,company ,new ,york ,successors to ! ,book ,dep>tm5ts ( ! ,mc,graw ,publi%+ ,company ,hill ,publi%+ ,company ,publi%]s ( ,books = ,electrical ,_w ,! ,eng9e]+ & ,m9+ ,j\rnal ,! ,eng9e]+ ,record ,p[] & ,! ,eng9e] ,electric ,railway ,j\rnal ,am]ican ,ma*9i/ ,,electric ,,transmission ,,( ,,wat] ,,p[] ,by ,,alton ,d4 ,,adams1 ,a4,m4 ,,memb] ,,am]ican ,,in/itute ,,( ,,electrical ,,eng9e]s ,,new ,,york ,,mcgraw-,,hill ,,book ,,co4 #aijf ,copyright$1 #aijf1 by ! ,mc,g,r,a,w ,,publi%+ ,,company ,,new ,,york ,,table ,,( ,,cont5ts ,,*apt] ,,page ,i4 ,,wat]-,,p[] ,,9 ,,electrical ,,supply #a ,,ii4 ,,utility ,,( ,,wat]-,,p[] ,,9 ,,electrical ,,supply #aj ,,iii4 ,,co/ ,,( ,,conductors ,,= ,,electric-,,p[] ,,transmission #ai ,,iv4 ,,advantages ,,( ,,! ,,cont9u\s ,,& ,,alt]nat+ ,,curr5t #ca ,v4 ,,! ,,physical ,,limits ,,( ,,electric-,,p[] ,,transmission #dd ,,vi4 ,,developm5t ,,( ,,wat]-,,p[] ,,= ,,electric ,,/ations #ea ,,vii4 ,,! ,,location ,,( ,,electric ,,wat]-,,p[] ,,/ations #fd ,,viii4 ,,design ,,( ,,electric ,,wat]-,,p[] ,,/ations #hc ,,ix4 ,,alt]nators ,,= ,,electrical ,,transmission #ajc ,x4 ,,trans=m]s ,,9 ,,transmission ,,sy/ems #abb ,,xi4 ,,swit*es1 ,,fuses1 ,,& ,,circuit-,,break]s #ace ,,xii4 ,,regulation ,,( ,,transmitt$ ,,p[] #aee ,,xiii4 ,,gu>d ,,wires ,,& ,,lightn+ ,,arre/]s #afh ,,xiv4 ,,electrical ,,transmission ,,"u ,,l& ,,& ,,wat] #ahg ,,xv4 ,,mat]ials ,,= ,,l9e ,,conductors #bjj ,,xvi4 ,,voltage ,,& ,,losses ,,on ,,transmission ,,l9es #bae ,,xvii4 ,,selection ,,( ,,transmission ,,circuits #bcc ,,xviii4 ,,pole ,,l9es ,,= ,,p[] ,,transmission #bdf ,,xix4 ,,entries ,,= ,,electric ,,transmission ,,l9es #bfa ,,xx4 ,,insulator ,,p9s #bgj ,,xxi4 ,,insulators ,,= ,,transmission ,,l9es #bhg ,,xxii4 ,,design ,,( ,,insulator ,,p9s ,,= ,,transmission ,,l9es #bih ,,xxiii4 ,,/eel ,,t[]s #cjf ,,index #cbg ,,electric ,,transmission ,,( ,,wat]-,,p[]4 ,,*apt] ,i4 ,,wat]-,,p[] ,,9 ,,electrical ,,supply4 ,electrical supply f transmitt$ wat]-p[] is n[ di/ribut$ 9 m ?an fifty cities ( ,nor? ,am]ica4 ,^! include ,mexico ,city1 ) a population ( #djb1jjj2 ,buffalo & ,san ,francisco1 ) #ceb1chg & #cdb1ghb respectively2 ,montreal1 ) #bff1hbf1 & ,los ,angeles1 ,/4 ,paul1 & ,m9neapolis1 ) populations t range betwe5 #ajj1jjj & #bjj1jjj ea*4 ,nor? & s\? ^! cities ext5d f ,quebec to ,&]son1 & f ,seattle to ,mexico ,city4 ,ea/ & we/ ! *a9 ( cities includes ,portl&1 ,spr+field1 ,albany1 ,buffalo1 ,hamilton1 ,toronto1 ,/4 ,paul1 ,butte1 ,salt ,lake ,city1 & ,san ,francisco4 ,to rea* ^! cities ! wat]-p[] is electrically transmitt$1 9 _m cases doz5s1 9 a numb] ( cases scores1 & 9 "o case m ?an two hundr$ miles4 ,9 ! ,ea/1 ,canada is ! site ( ! longe/ transmission1 t f ,%aw9igan ,falls to ,montreal1 a di/ance ( eighty-five miles4 ,f ,spi] ,falls to ,albany ! electric l9e is =ty miles 9 l5g?4 ,hamilton is ?irty-sev5 miles f t po9t on ! ,niag>a esc>pm5t1 :]e its electric p[] is develop$4 ,betwe5 ,/4 ,paul & its electric wat]-p[] /ation1 on ,apple ,riv]1 ! transmission l9e is tw5ty-five miles long4 ,! falls ( ! ,miss\ri ,riv] at ,caon ,f]ry are ! s\rce ( ! electrical en]gy di/ribut$ 9 ,butte1 sixty-five miles away4 ,los ,angeles draws electrical en]gy f a plant eighty-?ree miles di/ant on ! ,santa ,ana ,riv]4 ,f ,colgate p[]-h\se1 on ! ,yuba1 to ,san ,francisco1 by way ( ,mission ,san ,jos1 ! transmission l9e has a l5g? ( #bbj miles4 ,betwe5 ,electra g5]at+ /ation 9 ! ,si]ra ,nevada ,m\nta9s & ,san ,francisco is #aed miles by ! electric l9e4 ,illu/ration3 ,,fig4 #a4--,spi] ,falls ,transmission ,l9es4 ,^! transmissions involve l>ge p[]s z well z long di/ances4 ,! new plant on ! ,&roscogg9 is design$ to deliv] #aj1jjj horse-p[] = electrical supply 9 ,lewi/on1 ,me4 ,at ,spi] ,falls1 on ! ,hudson1 :5ce en]gy goes to ,albany & o!r cities1 ! electric g5]ators w h a capacity ( #cb1jjj horse-p[]4 ,f ! two wat]-p[] /ations at ,niag>a ,falls1 ) _! tw5ty-"o electric g5]ators ( #e1jjj horse-p[] ea*1 a total ( #aje1jjj1 m ?an #cj1jjj horse-p[] is regul>ly transmitt$ to ,buffalo alone2 ! great] "p ( ! capacity be+ devot$ to local indu/ries4 ,electrical supply 9 ,/4 ,paul is drawn f a wat]-p[] plant ( #d1jjj & 9 ,m9neapolis f a l plant ( #g1djj horse-p[] capacity4 ,! ,caon ,f]ry /ation1 on ! ,miss\ri1 t supplies electrical en]gy 9 bo? ,hel5a & ,butte1 has a capacity ( #aj1jjj horse-p[]4 ,bo? ,seattle & ,tacoma draw electrical supply f ! #h1jjj horse-p[] plant at ,snoqualmie ,falls4 ,! ,colgate p[]-h\se1 :i* develops en]gy = ,san ,francisco & a numb] ( small] places1 has electric g5]ators ( #ae1jjj horse-p[] aggregate capacity4 ,at ! ,electra g5]at+ /ation1 :]e en]gy is also transmitt$ to ,san ,francisco & o!r cities on ! way1 ! capacity is #ac1ccj horse-p[]4 ,electrical supply 9 ,los ,angeles is drawn f ! g5]at+ /ation ( #d1jjj horse-p[]1 on ! ,santa ,ana ,riv]1 & f two /ations1 on ,mill ,creek1 ) an aggregate ( #d1fjj1 mak+ a total capacity ( n less ?an #h1fjj horse-p[]4 ,five wat]-p[] /ations1 scatt]$ )9 a radius ( t5 miles & ) #d1bjj horse-p[] total capacity1 are ! s\rce ( electrical supply 9 ,mexico ,city4 ,! =ego+ are simply a "p ( ! m /rik+ illu/rations ( t developm5t by :i* fall+ wat] is g5]at+ hundr$s ( ?\s&s ( horse-p[] = electrical supply to millions ( population4 ,?is application ( great wat] p[]s to ! indu/rial wants ( di/ant cities is h>dly m ?an a decade old4 ,t5 ye>s ago ,%aw9igan ,falls 0 an almo/ unhe>d-( po9t 9 ! wilds ( ,canada4 ,spi] ,falls 0 m]ely a place ( sc5ic int]e/2 ! ,miss\ri at ,caon ,f]ry 0 n light+ a lamp or displac+ a p\nd ( coal2 t fall+ wat] 9 ! ,si]ra ,nevada ,m\nta9s %\ld light ! /reets & op]ate electric c>s 9 ,san ,francisco seem$ impossible1 & t div]sion ( ,niag>a1 :i* seems de/9$ to develop m ?an a million horse-p[] & leave dry ! precipices ov] :i* ! wat]s n[ plunge1 _h n yet begun4 ,9 "s few in/ances :]e wat]-p[] 0 locat$ 9 t[ns or cities1 x has be5 appli$ to electrical supply s9ce ! e>ly days ( ! indu/ry4 ,9 ! ma91 h[ev]1 ! supply ( electrical en]gy f wat]-p[] has be5 made possible only by long-di/ance transmission4 ,! ext5d+ radius ( electrical transmission = wat]-p[]s has =m$ ! greate/ inc5tive to _! developm5t4 ,?is developm5t 9 turn has react$ on ! conditions t limit electrical supply & has mat]ially ext5d$ ! field ( its application4 ,transmitt$ wat]-p[] has r$uc$ ! rates = electric s]vice4 ,x may n be easy to prove ?is r$uction by quot+ figures = net rates1 because ^! are n g5]ally publi%$1 b !re are o!r means ( rea*+ ! conclusion4 ,illu/ration3 ,,fig4 #b4--,snoqualmie ,falls ,transmission ,l9es4 ,9 ! field ( illum9ation electricity competes directly ) gas1 & 9 ! field ( motive p[] ) coal4 ,dur+ ! pa/ decade x is well kn[n t ! price ( gas has mat]ially decl9$ & ! price ( coal1 b>r+ ! rec5t /rike p]iod1 has c]ta9ly n increas$4 ,9 spite ( ^! r$uctions electrical supply f wat]-p[] has displac$ bo? gas & coal 9 _m in/ances4 ,moreov]1 ! expansion ( electric wat]-p[] sy/ems has be5 decid$ly great]1 z a rule1 ?an t ( electrical supply f /eam-driv5 /ations4 ,an example ( ! fact la/ /at$ may be se5 9 ,portl&1 ,me4 ,9 ! spr+ ( #ahii1 a company 0 =m$ to transmit & di/ribute electrical en]gy 9 t city f a wat]-p[] ab\t ?irte5 miles di/ant4 ,= "s ye>s1 prior to & s9ce ! date j nam$1 an ext5sive electric sy/em ) /eam-p[] equipm5t has exi/$ 9 ,portl&4 ,9 spite ( ?is1 ! sy/em us+ wat]-p[]1 on ,janu>y #a/1 #aijc1 _h a connect$ load ( #ceb enclos$ arcs & #bj1jjj inc&esc5t lamps1 besides #hce horse-p[] 9 motors4 ,comp>+ ! expansion ( electric wat]-p[] sy/ems ) ^? op]at$ by /eam1 :5 locat$ 9 diff]5t cities1 ,h>t=d & ,spr+field may be tak5 on ! "o h& & ,fall ,riv] & ,new ,b$=d on ! o!r4 ,! use ( wat]-p[] 9 electrical supply at ,h>t=d began 9 ,novemb]1 #ahia1 & has s9ce cont9u$ to an increas+ ext5t4 ,?r\gh\t ! same p]iod electrical supply 9 ,fall ,riv] has be5 d]iv$ exclusively f /eam4 ,9 #ahij ! population ( ,h>t=d 0 #ec1bcj1 & 9 #aijj x /ood at #gi1hej1 an increase ( #ej p] c5t4 ,at ! beg9n+ ( ! decade ,fall ,riv] _h a population ( #gd1cih1 & at its close ! figures 7 #ajd1hfc1 a rise ( #dj4i p] c5t4 ,9 #ahib ! connect$ load ( ! electric supply sy/em at ,fall ,riv] includ$ #dea arc & #g1hjj inc&esc5t lamps1 & motors aggregat+ #adj horse-p[]4 ,by #aija ?is load _h increas$ to #a1aaa arcs1 #bd1bed inc&esc5t lamps1 & #fjj horse-p[] 9 motors4 ,! electric supply sy/em at ,h>t=d 9 #ahib 0 s]v+ #hjj arcs1 #b1jjj inc&esc5t lamps1 & no motors4 ,aft] ! use ( transmitt$ wat]-p[] dur+ n9e ye>s ! connect$ load ( ! ,h>t=d sy/em _h come to include #a1fgi arcs1 #fh1gbe inc&esc5t lamps1 & #c1dgf horse-p[] ( motor capacity 9 #aija4 ,at ! beg9n+ ( ! decade ,h>t=d 0 f> beh9d ,fall ,riv] 9 bo? inc&esc5t lamps & motors1 b at ! end ,h>t=d _h ne>ly ?ree times z _m inc&esc5t lamps & ne>ly six times z great a capacity 9 connect$ motors4 ,z ,fall ,riv] _h a population 9 #aijj t 0 great] by ?irty-"o p] c5t4 ?an ! population ( ,h>t=d1 & ! p]c5tage ( increase dur+ ! decade 0 only #i4a l[] 9 ! =m] city1 wat]-p[] seems to h be5 ! mo/ pot5t factor 9 ! rise ( electric loads 9 ! latt]4 ,electric ga9s at ,h>t=d c\ld n h be5 due to ! abs5ce ( competition by gas1 = ! price ( gas !re 9 #aija 0 #a p] #a1jjj cubic feet1 :ile ! price 9 ,fall ,riv] 0 #a4aj = an equal am\nt4 ,wat]-p[] began to be us$ 9 electrical supply at ,spr+field dur+ ! latt] half ( #ahig4 ,9 t ye> ! connect$ load ( ! ,spr+field electric sy/em includ$ #a1jjf arcs1 #bd1ggh inc&esc5t lamps1 & motors ) a capacity ( #fdg horse-p[]4 ,five ye>s lat]1 9 #aijb1 ?is connect$ load _h ris5 to #a1cii arc lamps1 #de1gce inc&esc5t lamps1 & a capacity ( #a1jbe horse-p[] 9 electric motors4 ,at ,new ,b$=d1 9 #ahig1 ! electric sy/em 0 supply+ #djf arc & #bb1abb inc&esc5t lamps besides motors rat$ at #bih horse-p[]4 ,?is load1 9 #aijb1 _h *ang$ to #dhh arcs1 #ah1jee inc&esc5t lamps1 & #dcb horse-p[] 9 capacity ( electric motors4 ,f ! =ego+ figures x appe>s t :ile #hb arc lamps 7 add$ 9 ,new ,b$=d1 #cic su* lamps 7 add$ 9 ,spr+field4 ,:ile ! electric load at ,new ,b$=d 0 increas$ by #acd horse-p[] ( motors1 ! l increase at ,spr+field 0 #cgh horse-p[]1 & :ile ! =m] city lo/ #d1jfg f its load ( inc&esc5t lamps1 ! latt] ga9$ #bj1ieg ( ^! lamps4 ,dur+ all ^! *anges electrical supply 9 ,spr+field has come mo/ly f wat]-p[]1 & t 9 ,new ,b$=d has be5 ! product ( /eam4 ,population at ,spr+field numb]$ #dd1agi 9 #ahij & #fb1jei 9 #aijj1 an increase ( #dj4e p] c5t4 ,9 ! e>li] ( ^! ye>s ,new ,b$=d _h a population ( #dj1gcc1 & 9 ! lat] #fb1ddb1 an increase ( #ec4c p] c5t4 ,9 #aijb ! av]age price obta9$ = gas at ,spr+field 0 #a4jd & at ,new ,b$=d #a4ah p] #a1jjj cubic feet4 ,spr+field conta9s a prosp]\s gas sy/em1 & ! gross income !re f ! sale ( gas 0 ?irty-"o p] c5t great] 9 #aijb ?an 9 #ahig4 ,dur+ ?is same p]iod ( five ye>s ! gross income f sales ( electrical en]gy1 develop$ 9 l>ge "p by wat]-p[]1 increas$ =ty-sev5 p] c5t4 ,= ! five ye>s ( g5]al depression1 end+ 9 #ahig gross annual income ( gas sales 9 ,spr+field rose only five p] c5t1 & ! l electric income n9e p] c5t4 ,9 ! five ye>s la/ nam$ ! electrical supply sy/em 0 op]at$ ) coal4 ,! application ( transmitt$ wat]-p[] 9 electrical supply has displac$ /eam z a motive p[] 9 _m l>ge indu/rial plants t nev] w\ld h be5 op]at$ f /eam-driv5 electric /ations4 ,an example ( ?is sort exi/s at ,portl&1 :]e "o ( ! motors op]at$ by ! electric wat]-p[] sy/em1 9 an indu/rial plant1 has a capacity ( #cjj horse-p[]4 ,e p\nd ( coal burn$ 9 ,concord1 ,n4 ,h41 is haul$ by ! s+le /eam railway sy/em ent]+ t city1 :i* railway op]ates l>ge c> & repair %ops !re4 ,"s ye>s ago ! railway in/all$ a complete plant ( eng9es1 dynamos1 & motors = electric-driv+ ?r\gh\t ^! %ops4 ,^! eng9es & dynamos n[ /& idle & ! motor equipm5t1 ) an aggregate capacity ( #eij horse-p[]1 is op]at$ ) en]gy pur*as$ f ! local electrical supply sy/em & drawn f wat]-p[]4 ,ano!r /rik+ example ( ! ability ( electric wat]-p[] sy/ems to make p[] rates t are attractive to l>ge manufactur]s may be se5 at ,man*e/]1 ,n4 ,h4 ,"o ( ! l>ge/ manufactur+ plants 9 t city pur*ases en]gy = ! op]ation ( ! equival5t ( m ?an #g1jjj inc&esc5t lamps1 & ( motors rat$ at #igf horse-p[]1 f ! electrical supply sy/em !re1 ^: g5]at+ /ations are driv5 ma9ly by wat]-p[]4 ,! ,man*e/] electrical supply sy/em also furni%es en]gy1 ?r\gh a sub-/ation ( #hjj-;horse-p[] capacity1 to op]ate an electric railway connect+ ,man*e/] & ,concord4 ,?is electric l9e is own$ & op]at$ 9 common ) ! only /eam railway sy/em ( ,new ,hamp%ire1 s t ! only inducem5t to pur*ase en]gy f ! wat]-p[] sy/em seems to be "o ( price4 ,9 ,buffalo ! electric transmission sy/em f ,niag>a ,falls supplies l>ge motors ( ab\t #bj1jjj horse-p[] capacity 9 manufactur+ & indu/rial works1 & #g1jjj horse-p[] to ! /reet railway sy/em1 besides ano!r #d1jjj horse-p[] = g5]al s]vice 9 light+ & small motors4 ,few l>ge cities 9 ! ,unit$ ,/ates h *eap] coal ?an ,buffalo1 & 9 ,portl&1 ,concord1 & ,man*e/] coal prices are mod]ate4 ,9 ! ,rocky ,m\nta9 region1 :]e coal is m exp5sive1 ! great] "p ( ! loads ( "s electric wat]-p[] sy/ems is made up ( l>ge indu/rial works4 ,9 ,salt ,lake ,city ! electrical supply sy/em1 :i* draws its en]gy almo/ exclusively f wat]-p[]s1 _h a connect$ load ( motors aggregat+ #b1fjj horse-p[] z f> back z #aija1 & also furni%$ en]gy to op]ate ! local electric railway1 & sev]al smelt]s six miles s\? ( ! city1 besides all ! local light+ s]vice4 ,z good lump coal sells 9 ,salt ,lake = #d4ej p] ton1 slack at less ?an "o-half ?is figure1 & ! population !re by ! late c5sus 0 only #ec1eca1 ! figures = ! load ( motors are especially notable4 ,at ,hel5a en]gy f ! #aj1jjj horse-p[] /ation at ,caon ,f]ry op]ates ! local light+ & p[] sy/ems1 two smelt+ & a m9+ plant4 ,,cities ,,) ,,electrical ,,supply ,,f ,,wat]-,,p[]4 ---------------------------------------- -------------------- ,miles f ,wat]-,horse-,p[] ( ,city4 ,p[] to ,city4 ,wat]-,driv5 ,population4 ,/ations4 ---------------------------------------- -------------------- ,mexico ,city #aj to #ae #d1bjj #djb1jjj ,buffalo #bc ,a#cj1jjj #ceb1chg ,montreal #he -- #bff1hbf ,san ,francisco #adg #ac1ccj #cdb1ghb ,m9neapolis #aj #g1djj #bjb1gah ,/4 ,paul #be #d1jjj #afc1jfe ,los ,angeles #hc #h1fjj #ajb1dgi ,albany #dj #cb1jjj #id1aea ,portl&1 ,ore4 -- -- #ij1dbf ,h>t=d #aa #c1fjj #gi1hej ,spr+field1 ,mass4 #f #c1ghj #fb1jei ,man*e/]1 ,n4 ,h4 #ac4e #e1cgj #ei1ihg ,salt ,lake ,city #cf4e #aj1jjj #ec1eca ,portl&1 ,me4 #ac #b1ffj #ej1ade ,seattle -- #h1jjj #hj1fga ,butte #fe #aj1jjj #cj1dgj ,oakl& #adb #ae1jjj #ff1ijj ,lewi/on1 ,me4 #c #c1jjj #bc1gfa ,concord1 ,n4 ,h4 #d #a1jjj #ai1fcb ,hel5a1 ,mont4 #bj -- #aj1ggj ,hamilton1 ,ont4 #ce #h1jjj ,quebec #g #c1jjj ,dales1 ,ore4 #bg #a1ccj ---------------------------------------- -------------------- ,a ,p[] receiv$4 ,9 ,butte1 en]gy f ! /ation j nam$ op]ates ! works ( five smelt+ & m9+ companies1 driv+ motors t range f #a to #hjj horse-p[] 9 individual capacity4 ,! capacity ( ! ,butte sub-/ation is #g1fjj horse-p[]4 ,! great electric wat] p[] sy/em m>k$ by ! ,santa ,ana /ation at "o end & ! city ( ,los ,angeles at ! o!r1 eighty-?ree miles di/ant1 includes m ?an #afj miles ( transmission l9es1 sev]al hundr$ miles ( di/ribution circuits1 & supplies light & p[] 9 twelve cities & t[ns4 ,among ! cu/om]s ( ?is sy/em are an electric railway1 a numb] ( irrigation plants1 & a cem5t works4 ,^! works conta9 motors t range f #aj to #bjj horse-p[] ea* 9 capacity4 ,motors ( fifty horse-p[] or less are us$ at pump+ /ations 9 ! irrigation sy/ems4 ,applications ( wat]-p[] 9 electrical supply dur+ ! pa/ decade h prep>$ ! way = a mu* great] movem5t 9 ?is direction4 ,"w is n[ "u way = ! electric transmission ( wat]-p[]1 ei!r = ! fir/ "t or 9 l>g] am\nts1 to ,albany1 ,toronto1 ,*icago1 ,dulu?1 ,portl&1 ,oregon1 ,san ,francisco1 ,los ,angeles1 & doz5s ( o!r cities t might be nam$4 ,ano!r t5 ye>s w see ! great] "p ( electrical supply on ! ,am]ican cont95t drawn f wat]-p[]4 ,only ! l>ge/ city suppli$ f ea* wat]-p[] is nam$ above4 ,?us ! same transmission sy/em ent]s ,albany1 ,troy1 ,s*5ectady1 ,s>atoga1 & a numb] ( small] places4 ,,*apt] ,,ii4 ,,utility ,,( ,,wat]-,,p[] ,,9 ,,electrical ,,supply4 ,9 comp>atively few sy/ems is ! available wat]-p[] suffici5t to c>ry ! entire load at all h\rs ( ! day1 & dur+ all mon?s ( ! ye>1 s t ! "q ( h[ mu* fuel c be sav$ is an unc]ta9 "o = _m plants4 ,aga91 ! developm5t ( wat]-p[] (t5 involves a l>ge inve/m5t1 & may br+ a burd5 ( fix$ *>ges great] ?an ! value ( ! fuel sav$4 ,9 spite ( ^! conflict+ op9ions & factors1 ! application ( wat]-p[] 9 electrical sy/ems is n[ go+ on fa/] ?an ev] be=e4 ,if a sav+ ( fuel1 measur$ by ! available fl[ ( wat] dur+ ^? h\rs :5 x c be devot$ directly to electrical supply1 7 its only advantage1 ! numb] ( cases 9 :i* ?is p[] c\ld be utiliz$ at a pr(it w\ld be relatively small4 ,if1 on ! o!r h&1 all ( ! wat] t passes d[n a /ream c\ld be made to d electrical "w1 & if ! utilization ( ?is wat] _h o!r advantages ne>ly or q z great z ! r$uction ( exp5se = coal1 !n _m wat]-p[]s w\ld await only developm5t to br+ pr(it to _! own]s4 ,no "p ( ! problem is m unc]ta9 ?an ! fir/ co/ & subsequ5t fix$ *>ges connect$ ) ! developm5t ( wat]-p[]4 ,to br+ out ! real conditions1 ! detail$ facts z to "o or m plants may be ( great] value ?an m]e g5]al /atem5ts cov]+ a wide range ( cases4 ,on a c]ta9 small riv] ! entire wat] privilege at a po9t :]e a fall ( f\rte5 feet c\ld be made available 0 obta9$ sev]al ye>s ago4 ,at ?is po9t a sub/antial /one & concrete dam 0 built1 & also a /one & brick p[]-h\se ) concrete floor & /eel truss ro(4 ,9 ?is p[]-h\se 7 in/all$ electric g5]ators ( #hjj kil[atts total capacity1 direct-connect$ to horizontal turb9e :eels4 ,! entire co/ ( ! real e/ate necess>y to secure ! wat]-p[] privilege plus ! co/ ( all ! improvem5ts 0 ab\t #acj1jjj4 ,m ?an en\gh wat]-p[] to drive ! #hjj-kil[att g5]ators at full load 0 e/imat$ to be available1 except at times ( exceptionally l[ wat]4 ,at ?is plant ! inve/m5t = ! wat]-p[] site1 developm5t1 & complete equipm5t 0 ?us #afb p] kil[att capacity ( g5]ators in/all$4 ,all[+ #fe days ( l[ wat]1 ^! g5]ators ( #hjj kil[atts capacity may be op]at$ #cjj days p] ye>4 ,if ! runn+ "t av]ages t5 h\rs daily at full load1 ! en]gy deliv]$ p] ye> is #b1djj1jjj kil[att h\rs4 ,t5 p] c5t ( ! total inve/m5t %\ld be ample to cov] int]e/ & depreciation *>ges1 & ?is am\nts to #ac1jjj ye>ly4 ,x foll[s t ! items ( int]e/ & depreciation on ! orig9al inve/m5t repres5t a *>ge ( #j4ed c5t p] kil[att h\r on ! assum$ en]gy output at ?is plant4 ,?is en]gy is transmitt$ a few miles & us$ 9 ! electrical supply sy/em ( a l>ge city4 ,on ano!r riv] ! entire wat] privilege 0 secur$ ab\t f\r ye>s ago at a po9t :]e a fall ( m ?an #bj feet betwe5 l$ges ( rock c\ld be obta9$ & m ?an #b1jjj horse-p[] c\ld be develop$4 ,at ?is po9t a masonry dam & brick p[]-h\se 7 built1 & horizontal turb9e :eels 7 in/all$1 direct-connect$ to electric g5]ators ( #a1ejj kil[atts total capacity4 ,! entire co/ ( real e/ate1 wat] rights1 dam1 build+1 & equipm5t 9 ?is case 0 ab\t #bej1jjj4 ,assum+1 z be=e1 t g5]ators may be op]at$ at full capacity = #aj h\rs p] day dur+ #cjj days p] ye>1 ! en]gy deliv]$ by ?is plant am\nts to #d1ejj1jjj kil[att h\rs ye>ly4 ,! all[ance ( #aj p] c5t on ! entire inve/m5t = int]e/ & depreciation is repres5t$ by #be1jjj ye>ly 9 ?is case1 or #j4ef c5t p] kil[att h\r ( probable output4 ,en]gy f ?is plant is transmitt$ & us$ 9 a l>ge sy/em ( electrical supply4 ,if1 ?r\gh lack ( wat] or inability to /ore wat] or en]gy at times :5 x is n want$1 g5]ators _c be op]at$ at full capacity dur+ ! av]age numb] ( h\rs assum$ above1 ! item ( int]e/ & depreciation p] unit ( deliv]$ en]gy mu/ be high] ?an t comput$4 ,) ! possible figure = ?is item at less ?an six-t5?s ( a c5t p] kil[att h\r1 !re is opportunity = "s increase be=e x becomes prohibitive4 ,at ! plant la/ nam$ ! entire inve/m5t am\nt$ to #aff p] kil[att capacity ( connect$ g5]ators1 comp>$ ) #afb 9 ! =m] case1 & ^! figures may be tak5 z fairly repres5tative = ! developm5t ( wat]-p[] 9 a fir/-class mann] on small riv]s1 "u favorable conditions4 ,9 bo? ( ^! in/ances ! p[]-h\ses are q close to ! dams4 ,if long canals or pipe l9es mu/ be built to convey ! wat]1 ! exp5se ( developm5t may be greatly increas$4 ,"o advantage ( wat]- ov] /eam-p[] is ! small] co/ ( ! build+ ) ! =m] = a giv5 capacity ( plant4 ,! build+ = direct-connect$ electric g5]ators1 driv5 by wat]-:eels1 is relatively small & simple4 ,space = fuel1 boil]s1 economiz]s1 fe$-wat] heat]s1 cond5s]s1 /eam pip+1 & pumps is n requir$ :]e wat]-p[] is us$4 ,no *imney or app>atus = me*anical draught is ne$$4 ,! model electric /ation op]at$ by wat]-p[] usually consi/s ( a s+le room ) no basem5t "u x4 ,"o su* /ation has floor dim5sions #bg by #eb feet1 giv+ an area ( #a1djd squ>e feet1 & conta9s g5]ators ( #hjj kil[atts capacity4 ,?is gives #a4ge squ>e feet ( floor space p] kil[att ( g5]ators4 ,9 ?is /ation !re is ample room = all purposes1 includ+ erection or removal ( ma*9]y4 ,next to ! sav+ ( fuel1 ! greate/ advantage ( wat]-p[] is due to ! relatively small requirem5ts = labor at g5]at+ /ations :]e x is us$4 ,?is is well illu/rat$ by an example f actual practice4 ,9 a mod]n wat]-p[] /ation t contributes to electrical supply 9 a l>ge city ! g5]ator capacity is #a1bjj kil[atts4 ,all ( ! labor connect$ ) ! op]ation ( ?is /ation dur+ ne>ly tw5ty-f\r h\rs p] day is done by two att5dants work+ alt]nate %ifts4 ,^! att5dants live close to ! /ation 9 a h\se own$ by ! electric company1 & receive #fj ea* p] mon? 9 addition to h\se r5t4 ,consid]+ ! location1 #ab p] mon? is probably ample all[ance = ! r5t4 ,?is br+s ! total exp5se ( op]ation at ?is /ation = labor up to #acb p] mon?1 or #a1ehd p] ye>1 a sum correspond+ to #a4cb ye>ly p] kil[att ( g5]ator capacity4 ,at /eam-p[] /ations ( ab\t ! above capacity1 op]at+ tw5ty-f\r h\rs daily1 #f is an approximate ye>ly co/ ( labor p] kil[att ( g5]ators 9 use4 ,x ?us appe>s t wat]-p[] plants may be op]at$ at less ?an "o-f\r? ( ! labor exp5se necess>y at /eam /ations p] unit ( capacity4 ,on an av]age1 ! comb9$ co/ ( fuel & labor at electric /ations driv5 by /eam-p[] is a little m ?an #gf p] c5t ( _! total co/ ( op]ation4 ,( ?is total1 labor repres5ts ab\t #bh1 & fuel ab\t #dh p] c5t4 ,wat]-p[]1 by disp5s+ ) fuel & ) ?ree-f\r?s ( ! labor *>ge1 r$uces ! exp5se ( op]ation at electric /ations by fully #fi p] c5t4 ,b ?is great sav+ 9 ! op]at+ exp5ses ( electric /ations c be made only :]e wat] entirely displaces coal4 ,if "p wat]-p[] & "p coal are us$1 ! result dep5ds on ! proportion ( ea*1 & is obvi\sly mu* affect$ by ! v>iations ( wat]-p[] capacity4 ,9 su* a mix$ sy/em ! sav+ effect$ by wat]-p[] mu/ also dep5d on ! ext5t to :i* its en]gy c be absorb$ at all h\rs ! day4 ,by f> ! great] numb] ( electric /ations us+ wat]-p[] are oblig$ also to employ /eam dur+ ei!r "s mon?s 9 ! ye> or "s h\rs 9 ! day1 or bo?4 ,illu/ration3 ,,en]gy ,,curves ,,f ,,wat] ,,p[] ,,electric ,,/ations4 ,,fig4 #c4 ,x is highly important1 !re=e1 to det]m9e1 z ne>ly z may be1 ! answ]s to ?ree que/ions3 ,fir/1 :at v>iations are to be expect$ 9 ! capacity ( a wat]-p[] dur+ ! sev]al mon?s ( a ye>8 ,second1 if ! daily fl[ ( wat] is equal 9 capacity to ! daily output ( electrical en]gy1 h[ f> c ! wat]-p[] be devot$ to ! developm5t ( t en]gy8 ,?ird1 ) a wat]-p[] suffici5t to c>ry all electrical loads at times ( mod]ately high wat]1 :at p]c5tage ( ! ye>ly output ( en]gy 9 a g5]al supply sy/em c be d]iv$ f ! wat]8 ,to ! fir/ ( ^! que/ions exp]i5ce alone c furni% an answ]4 ,v>iations 9 ! dis*>ge ( riv]s dur+ ! diff]5t mon?s ( a ye> are v great4 ,9 a plant laid out ) good eng9e]+ skill "s provision w be made = ! /orage ( wat]1 & ! capacity ( g5]at+ equipm5t w correspond to "s po9t betwe5 ! highe/ & l[e/ rates ( dis*>ge4 ,curve ,no4 #a 9 ! diagram on ! opposite page repres5ts ! en]gy output at an electric /ation driv5 entirely by wat]-p[] f a small /ream dur+ ! twelve mon?s ( #aija1 ! entire fl[ ( ! /ream be+ utiliz$4 ,dur+ ,decemb]1 #aija1 ! output ( ?is /ation 0 #ebg1gjj kil[atts1 & 0 great] ?an t 9 any o!r mon? ( ! ye>4 ,tak+ ?is output at #ajj p] c5t1 ! curve is platt$ to %[ ! p]c5tage atta9$ by ! deliv]$ en]gy 9 ea* ( ! o!r mon?s4 ,at ! l[e/ po9t on ! curve1 correspond+ to ! mon? ( ,febru>y1 ! output ( en]gy 0 only slightly ov] #cc p] c5t ( t 9 ,decemb]4 ,dur+ n9e o!r mon?s ( ! ye> ! proportion ( en]gy output to t 9 ,decemb] 0 ov] #fj & 9 ?ree mon?s ov] #hj p] c5t4 ,= ! twelve mon?s ! av]age deliv]y ( en]gy p] mon? 0 #gc4g p] c5t ( t dur+ ,decemb]4 ,,p]c5tages ,,( ,,en]gy ,,deliv]$ ,,9 ,,diff]5t ,,mon?s1 #aija4 ,janu>y #fh4j ,febru>y #cc4a ,m>* #hj4e ,april #ha4g ,may #gg4i ,june #eh4f ,july #fg4g ,augu/ #ge4h ,septemb] #gi4c ,octob] #fe4i ,novemb] #ie4h ,decemb] #ajj4j ,at a some:at small wat]-p[] /ation on ano!r riv] ) a wat]%$ less precipit\s ?an t ( ! /ream j consid]$1 ! foll[+ results 7 obta9$ dur+ ! twelve mon?s end+ ,june #cj?1 #aijj4 ,= ?is plant ! l>ge/ mon?ly output ( en]gy 0 9 ,novemb]1 & ?is output is tak5 at #ajj p] c5t4 ,! smalle/ deliv]y ( en]gy 0 9 ,octob]1 :5 ! p]c5tage 0 #ec4a ( ! am\nt = ,novemb]4 ,9 ea* ( sev5 o!r mon?s ( ! ye> ! output ( en]gy 0 above #hj p] c5t ( t 9 ,novemb]4 ,dur+ ,m>*1 ,april1 ,may1 & ,june ! wat]-p[] yield$ all ( ! en]gy requir$ 9 ! electrical supply sy/em ) :i* x 0 connect$1 & c\ld1 no d\bt1 h done m "w if necess>y4 ,= ! twelve mon?s ! av]age deliv]y ( en]gy p] mon? 0 #hj4f p] c5t ( t 9 ,novemb]1 ! mon? ( greate/ output4 ,,p]c5tages ,,( ,,en]gy ,,deliv]$ ,,9 ,,diff]5t ,,mon?s1 #ahii ,,& #aijj4 ,july #fh4f ,augu/ #fi4a ,septemb] #gc4c ,octob] #ec4a ,novemb] #ajj4j ,decemb] #hg4j ,janu>y #hd4i ,febru>y #ia4c ,m>* #ih4e ,april #he4g ,may #hj4h ,june #gd4i ,! g5tl] slopes & bett] /orage facilities ( ?is second riv] %[ _! effect 9 an av]age mon?ly deliv]y ( en]gy #f4i p] c5t high] z to ! output 9 a mon? :5 x 0 greate/ ?an ! l p]c5tage = ! wat]-p[] fir/ consid]$4 ,^! two wat]-p[] illu/rate :at c be done ) only v mod]ate /orage capacities on ! riv]s involv$4 ,at bo? /ations mu* wat] escapes ov] ! dams dur+ sev]al mon?s ( ea* ye>4 ,) en\gh /orage space to reta9 all wat]s ( ^! riv]s until want$ ! en]gy outputs c\ld be l>gely increas$4 ,z may be se5 by inspection ( curve ,no4 #b1 ! second wat]-p[] has small] fluctuations ( capacity1 z well z a high] av]age p]c5tage ( ! maximum output ?an ! wat]-p[] illu/rat$ by curve ,no4 #a4 ,if ! dis*>ge ( a /ream dur+ ea* tw5ty-f\r h\rs is j suffici5t to develop ! electrical en]gy requir$ 9 a supply sy/em dur+ t "t1 ! wat] may be made to d all ( ! electrical "w 9 "o ( two ways4 ,if ! wat]-p[] has en\gh /orage capacity beh9d x to hold ! excess ( wat] dur+ "s h\rs ( ! day1 !n x is only necess>y to in/all en\gh wat]-:eels & electric g5]ators to c>ry ! maximum load4 ,%\ld ! /orage capacity = wat] be lack+1 or ! equipm5t ( g5]at+ app>atus be insuffici5t to "w at ! maximum rate dem&$ by ! electrical sy/em1 !n an electric /orage batt]y mu/ be employ$ if all ( ! wat] is to be utiliz$ & made to d ! electrical "w4 ,! greate/ fluctuations betwe5 maximum & m9imum daily loads at electric light+ /ations usually occur 9 ,decemb] & ,janu>y4 ,! ext5t ( ^! fluctuations is illu/rat$ by curve ,no4 #c1 :i* repres5ts ! total load on a l>ge electrical supply sy/em dur+ a typical week-day ( ,janu>y1 #aija4 ,on ?is day ! maximum load 0 #b1gbj & ! m9imum load #fab kil[atts1 or #bb4e p] c5t ( ! highe/ rate ( output4 ,dur+ ! day 9 "q ! total deliv]y ( en]gy = ! tw5ty-f\r h\rs 0 #cj1bdi kil[att h\rs1 s t ! av]age load p] h\r 0 #a1bfj kil[atts4 ,?is av]age is #df p] c5t ( ! maximum load4 ,computation ( ! area includ$ by curve ,no4 #c above ! av]age load l9e ( #a1bfj kil[atts %[s t ab\t #ag4h p] c5t ( ! total output ( en]gy = ! day 0 deliv]$ above ! av]age load1 t is1 9 addition to an output at av]age load4 ,x fur!r appe>s by inspection ( ?is load curve t ?is deliv]y ( en]gy above ! av]age load l9e took place dur+ #ab4c h\rs ( ! day1 s t its av]age rate ( deliv]y p] h\r 0 #dch kil[atts4 ,if a wat]-p[] compet5t to c>ry a load ( #a1bfj kil[atts tw5ty-f\r h\rs p] day be appli$ to ! sy/em illu/rat$ by curve ,no4 #c1 !n ab\t #ag4h p] c5t ( ! en]gy ( ! wat] = ! entire day mu/ be /or$ dur+ #aa4g h\rs & lib]at$ 9 ! rema9+ #ab4c h\rs4 ,?is p]c5tage ( ! total daily en]gy ( ! wat] am\nts to #cf p] c5t ( its en]gy dur+ ! h\rs t /orage takes place4 ,if all ( ! /orage is done ) wat]1 ! electric g5]ators mu/ be able to "w at ! rate ( #b1gbj kil[atts1 ! maximum load4 ,if all ( ! /orage is done 9 electric batt]ies1 ! use ( wat] may be uni=m ?r\gh\t ! day1 & ! g5]ator capacity mu/ be en\gh above #a1bfj kil[atts to make up = losses 9 ! batt]ies4 ,:]e batt]ies are employ$ ! am\nt ( wat] w be some:at great] ?an t necess>y to op]ate ! load directly ) g5]ators1 because ( ! batt]y losses4 ,9 spite ( ! l>ge fluctuations ( electrical loads ?r\gh\t ea* tw5ty-f\r h\rs1 x is ?us comp>atively easy to op]ate !m ) wat]-p[]s t are little1 if any1 above ! requirem5ts ( ! av]age loads4 ,p]haps ! mo/ important "q relat+ to ! use ( wat]-p[] 9 electrical supply is :at p]c5tage ( ! ye>ly output ( en]gy c be d]iv$ f wat] :]e ?is p[] is suffici5t to c>ry ! entire load dur+ a "p ( ! ye>4 ,) /orage area = all surplus wat] 9 any season1 ! am\nt ( "w t c\ld be done by a /ream might be calculat$ directly f ! records ( its annual dis*>ge ( wat]4 ,z su* /orage areas = surplus wat] h seldom1 or nev]1 be5 made available 9 connection ) electrical sy/ems1 ! be/ assurance z to ! p]c5tage ( ye>ly output t may be d]iv$ f wat]-p[] is f\nd 9 ! exp]i5ce ( exi/+ plants4 ,! "q n[ to be consid]$ diff]s mat]ially f t involv+ m]ely ! v>iations ( wat]-p[] 9 ! sev]al mon?s1 or ev5 ! possible ye>ly output f wat]-p[]4 ,! ratio ( output f wat]-p[] to ! total ye>ly output ( an electrical sy/em includes ! result ( load fluctuations 9 e tw5ty-f\r h\rs & ! v>iable dem&s = electrical en]gy 9 diff]5t mon?s1 z well z *anges 9 ! am\nt ( wat]-p[] available ?r\gh ! seasons4 ,9 ord] to %[ ! comb9$ result ( ^! ?ree important factors curve ,no4 #d has be5 con/ruct$4 ,?is indicates ! p]c5tages ( total semi-ye>ly outputs ( electrical en]gy d]iv$ f wat]-p[] 9 two supply sy/ems4 ,ea* half-ye> ext5ds ei!r f ,janu>y to ,june1 inclusive1 or f ,july to ,decemb]1 inclusive1 & ?us cov]s a wet & dry season4 ,ea* half-ye> also includes a p]iod ( maximum & "o ( m9imum dem& = electrical en]gy 9 light+4 ,! p]iod ( l>ge/ wat] supply usually ne>ly co9cides ) t ( heavie/ light+ load1 b ?is is n always true4 ,electrical sy/ems h purposely be5 select$ 9 :i* ! wat]-p[] 9 at lea/ "o mon? ( ea* half-ye> 0 ne>ly or q suffici5t to c>ry ! entire electrical load4 ,! p]c5tage ( en]gy f wat]-p[] to ! total en]gy deliv]$ by ! sy/em is pres5t$ = ea* ( five half-ye>s4 ,?ree ( ! half-ye>s ea* run f ,july to ,decemb]1 & two ext5d f ,janu>y to ,june1 respectively4 ,! half ye>s t %[ p]c5tages ( #ff4h1 #hj4b1 & #ie4f1 respectively1 = ! relation ( en]gy f wat]-p[] to ! total electrical output relate to "o sy/em1 & ! half ye>s t %[ p]c5tages ( #ha4ig & #id4c = ! en]gy f wat]-p[] relate to ano!r sy/em4 ,= ! half-ye> :5 #ff4h p] c5t4 ( ! output ( ! electrical sy/em 0 d]iv$ f wat]-p[]1 ! total output ( ! sy/em 0 #c1iff1jbf kil[att h\rs4 ,dur+ ! mon? ( ,decemb] 9 ?is half-ye> m ?an #ih p] c5t ( ! electrical en]gy deliv]$ by ! sy/em 0 f wat]-p[]1 ?\gh ! av]age = ! six mon?s 0 only #ff4h p] c5t f wat]4 ,9 ! foll[+ six mon?s1 f ,janu>y to ,june1 ! electrical supply sy/em deliv]$ #d1afa1ged kil[att h\rs1 & ( ?is am\nt ! wat]-p[] furni%$ #hj4b p] c5t4 ,= ! six mon?s j nam$1 "o mon?1 ,may1 saw #ii p] c5t ( all ! deliv]$ en]gy d]iv$ f wat]-p[]4 ,! same sy/em dur+ ! next half-ye>1 f ,july to ,decemb]1 )\t any addition to its wat]-p[] developm5t or equipm5t1 got #ie4f p] c5t ( its entire en]gy output f wat]-p[]1 & ?is output am\nt$ to #d1dae1ide kil[att h\rs4 ,9 "o mon? ( ! half-ye> j nam$ only #j4b p] c5t ( ! output 0 g5]at$ ) /eam-p[]4 ,^! ?ree successive half ye>s illu/rate ! fluctuations ( ! ratio betwe5 wat]-p[] outputs & ! dem&s = en]gy on a s+le sy/em ( electrical supply4 ,! p]c5tage ( #ha4i = en]gy d]iv$ f wat]-p[] dur+ ! half-ye> f ,july to ,decemb] repres5ts ! ratio ( output f wat] to ! total = an electrical supply sy/em :]e wat] g5]at$ #id p] c5t ( all ! en]gy deliv]$ 9 "o mon?4 ,9 ! same sy/em dur+ ! foll[+ six mon?s1 ) exactly ! same wat]-p[] equipm5t1 ! p]c5tage ( output f wat]-p[] 0 #id4c ( ! total kil[att-h\rs deliv]$ by ! sy/em4 ,?is result 0 rea*$ 9 spite ( ! fact t ! total outputs ( ! sy/em 9 ! two half-ye>s 7 equal to )9 less ?an "o p] c5t4 ,! lesson f ! record ( ^! five half-ye>s is t comp>atively l>ge v>iations are to be expect$ 9 ! p]c5tage ( en]gy develop$ by wat]-p[] to ! total output ( electrical supply sy/ems 9 diff]5t half-ye>s4 ,b1 9 spite ( ^! v>iations1 ! portion ( electrical loads t may be c>ri$ by wat]-p[] is suffici5t to w>rant its rapidly ext5d+ application to light+ & p[] 9 cities & t[ns4 ,,*apt] ,,iii4 ,,co/ ,,( ,,conductors ,,= ,,electric-,,p[] ,,transmission4 ,electrical transmission ( en]gy involves problems q di/9ct f its developm5t4 ,a great wat]-p[]1 or a location :]e fuel is *eap1 may (f] opportunity to g5]ate electrical en]gy at an exceptionally l[ co/4 ,?is en]gy may be us$ s close to ! po9t ( its developm5t t ! co/ ( transmission is too small = sep>ate consid]ation4 ,an example ( conditions :]e ! important problems ( transmission are abs5t exi/s 9 ! num]\s factories gr\p$ ab\t ! great wat]-p[] plants at ,niag>a & draw+ electrical en]gy f x4 ,9 su* a case en]gy fl[s directly f ! dynamos1 driv5 by wat]-p[]1 to ! lamps1 motors1 *emical vats1 & electric heat]s ( consum]s ?r\gh ! m$ium1 p]haps1 ( local trans=m]s4 ,"h ! co/s & losses ( transmitt+ or di/ribut+ equipm5ts are m9or matt]s1 comp>$ ) ! developm5t ( ! en]gy4 ,if1 n[1 en]gy f ! wat]-p[] is to be transmitt$ ov] a di/ance ( _m miles1 a new set ( co/s is to be met4 ,9 ! fir/ place1 x w be necess>y to raise ! voltage ( ! transmitt$ en]gy mu* above ! pressure at ! dynamos 9 ord] to save 9 ! weight & co/ ( conductors = ! transmission l9e4 ,?is increase ( voltage requires trans=m]s ) capacity equal to ! maximum rate at :i* en]gy is to be deliv]$ to ! l9e4 ,^! trans=m]s w add to ! co/ ( ! en]gy t !y deliv] 9 two ways3 by ! absorption ( "s en]gy to =m heat1 & by ! sum ( annual int]e/1 ma9t5ance1 & depreciation *>ges on ! price paid = !m4 ,o!r additions to ! co/ ( en]gy deliv]$ by ! transmission l9e mu/ be made to cov] ! annual int]e/1 ma9t5ance1 & depreciation *>ges on ! am\nt ( ! l9e inve/m5t1 & to pay = ! en]gy *ang$ to heat 9 ! l9e4 ,ne> ! po9ts :]e ! en]gy is to be us$1 ! transmission l9e mu/ end 9 trans=m]s to r$uce ! voltage to a safe figure = local di/ribution4 ,?is second set ( trans=m]s w fur!r add to ! co/ ( ! deliv]$ en]gy 9 ! same ways z ! =m] set4 ,f ^! facts x is evid5t t1 to w>rant an electrical transmission1 ! value ( en]gy at ! po9t ( di/ribution %\ld at lea/ equal ! value at ! g5]at+ plant plus ! co/ ( ! transmission4 ,kn[+ ! co/ ( en]gy at "o end ( ! transmission l9e & its value at ! o!r1 ! diff]5ce betwe5 ^! two repres5ts ! maximum co/ at :i* ! transmission w pay4 ,?ree ma9 factors are conc]n$ 9 ! co/ ( electric p[] transmission1 namely1 ! trans=m]s1 ! pole l9e1 & ! wire or conductors4 ,^! factors ent] into ! co/ ( transmitt$ en]gy 9 v diff]5t degrees1 accord+ to ! circum/ances ( ea* case4 ,! maximum & av]age rates ( en]gy transmission1 ! total voltage1 ! p]c5tage ( l9e loss1 & ! l5g? ( ! l9e ma9ly det]m9e ! relative importance ( ! trans=m]s1 pole l9e1 & conductors 9 ! total co/ ( deliv]$ en]gy4 ,fir/ co/ ( trans=m]s v>ies directly ) ! maximum rate ( transmission1 & is ne>ly indep5d5t ( ! voltage1 ! l5g? ( ! transmission1 & ! p]c5tage ( l9e loss4 ,a pole l9e *anges 9 fir/ co/ ) ! l5g? ( ! transmission1 b is ne>ly indep5d5t ( ! o!r factors4 ,l9e conductors1 = a fix$ maximum p]c5tage ( loss1 v>y 9 fir/ co/ directly ) ! squ>e ( ! l5g? ( ! transmission & ) ! rate ( ! transmission2 b _! fir/ co/ decreases z ! p]c5tage ( l9e loss increases & z ! squ>e ( ! voltage ( transmission increases4 ,if a giv5 am\nt ( p[] is to be transmitt$1 at a c]ta9 p]c5tage ( loss 9 ! l9e & at a fix$ voltage1 ov] di/ances ( #ej1 #ajj1 & #bjj miles1 respectively1 ! =ego+ pr9ciples lead to ! foll[+ conclusions3 ,! capacity ( trans=m]s1 be+ fix$ by ! rate ( transmission1 w be ! same = ei!r di/ance1 & _! co/ is !re=e con/ant4 ,trans=m] losses1 int]e/1 depreciation1 & repairs are also con/ant4 ,! co/ ( pole l9e1 dep5d+ on its l5g?1 w be twice z great at #ajj & f\r times z great at #bjj z at #ej miles4 ,int]e/1 depreciation1 & repairs w also g up directly ) ! l5g? ( ! pole l9es4 ,l9e conductors w co/ f\r times z mu* = ! #ajj- z = ! #ej-mile transmission1 because _! weight w be f\r times z great1 & ! annual int]e/ & depreciation w g up at ! same rate4 ,= ! transmission ( #bjj miles ! co/ ( l9e conductors & _! weight w be sixte5 times z great z ! co/ at #ej miles4 ,x foll[s t int]e/1 depreciation1 & ma9t5ance w be increas$ sixte5 times ) ! #bjj-mile transmission ov] :at !y 7 at #ej miles1 if voltage & l9e loss are con/ant4 ,a concrete example ( ! co/ ( electric p[] transmission ov] a giv5 di/ance w illu/rate ! practical application ( ^! pr9ciples4 ,let ! problem be to deliv] electrical en]gy 9 a city di/ant #ajj miles f ! g5]at+ plant4 ,trans=m]s ) approximately twice ! capacity correspond+ to ! maximum rate ( transmission mu/ be provid$1 because "o set is requir$ at ! g5]at+ & ano!r at ! deliv]y /ation4 ,! co/ ( ^! trans=m]s w be approximately #g4ej p] horse-p[] = any l>ge capacity4 ,reliability is ( ! utmo/ importance 9 a great p[] transmission1 & ?is requires a pole l9e ( ! mo/ sub/antial con/ruction4 ,su* a l9e 9 a locality :]e wood5 poles c be _h at a mod]ate price w co/1 ) conductors 9 position1 ab\t #gjj p] mile1 exclusive ( ! co/ ( ! conductors !mselves or ( ! "r ( way b includ+ ! co/ ( erect+ ! conductors4 ,! #ajj miles ( pole l9e 9 ! pres5t case %\ld1 !re=e1 be set d[n at a co/ ( #gj1jjj4 ,a l>ge deliv]y ( p[] mu/ be made to w>rant ! con/ruction ( s long & exp5sive a l9e1 & #aj1jjj horse-p[] may be tak5 z ! maximum rate ( deliv]y4 ,on ! basis ( two horse-p[] ( trans=m] capacity = ea* horse-p[] ( ! maximum deliv]y rate1 trans=m]s ) a capacity ( #bj1jjj horse-p[] are necess>y = ! pres5t transmission4 ,at #g4ej p] horse-p[] capacity1 ! fir/ co/ ( ^! trans=m]s is #aej1jjj4 ,be=e ! weight & co/ ( l9e conductors c be det]m9$1 ! voltage at :i* ! transmission %all be c>ri$ out & ! p]c5tage ( ! en]gy to be lo/ 9 ! conductors at p]iods ( maximum load mu/ be decid$ on4 ,! voltage to be us$ is a matt] ( eng9e]+ judgm5t1 bas$ 9 l>ge "p on exp]i5ce1 & _c be det]m9$ by calculation4 ,9 a transmission ( #ajj miles ! co/ ( conductors is c]ta9 to be a v heavy item1 &1 z ?is co/ decreases z ! squ>e ( ! voltage goes up1 x is desirable to pu% ! voltage z high z ! requirem5ts = reliable s]vice p]mit4 ,a transmission l9e #adb miles long1 f ! m\nta9s to ,oakl&1 ,cal41 has be5 9 con/ant & successful use = sev]al ye>s ) #dj1jjj volts pressure4 ,?is l9e passes ?r\gh wet z well z dry climate4 ,x seems saf] to conclude1 !re=e1 t #dj1jjj volts may be us$ 9 mo/ places ) good results4 ,hav+ decid$ on ! am\nt ( p[] & ! voltage & l5g? ( ! transmission1 ! requir$ weight ( conductors w v>y inv]sely z ! p]c5tage ( en]gy lo/ z heat 9 ! l9e4 ,! be/ p]c5tage ( loss dep5ds on ! numb] ( factors1 "s ( :i*1 su* z ! co/ ( en]gy at ! g5]at+ plant1 are peculi> to ea* case4 ,z a provisional figure1 bas$ 9 "p on ! practice else:]e1 ! loss on ! l9e "h consid]$ may be tak5 at #aj p] c5t4 :5 transmitt+ ! full load ( #aj1jjj horse-p[]4 ,if ! l9e is con/ruct$ on ?is basis ! p]c5tage ( loss w be proportionately less = any small] load4 ,?us1 :5 ! l9e is transmitt+ only #e1jjj horse-p[]1 ! loss w am\nt to #e p] c5t4 ,dur+ ! great] portion ( ea* day ! dem& = p[] is c]ta9 to be less ?an ! maximum figure1 s t a maximum loss ( #aj p] c5t w correspond to an av]age loss on all ! p[] deliv]$ to ! l9e ( probably less ?an #g p] c5t4 ,9 ord] to deliv] #aj1jjj horse-p[] by ! trans=m]s at a receiv+ /ation f a g5]at+ plant #ajj miles di/ant :]e ! pressure is #dj1jjj volts1 ! copp] conductors mu/ h a weight ( ab\t #a1ejj1jjj p\nds1 if ! loss ( en]gy 9 !m is #aj p] c5t ( ! en]gy deliv]$ to ! l9e4 ,tak+ ^! conductors at a m$ium price ( #ae c5ts p] p\nd1 _! co/ am\nts to #bbe1jjj4 ,! comb9$ co/ ( ! trans=m]s1 pole l9e1 & l9e conductors1 z n[ e/imat$1 am\nts to #dde1jjj4 ,no acc\nt is tak5 ( ! "r-(-way = ! pole l9e1 because 9 _m cases ?is w\ld co/ no?+1 ! public roads be+ us$ = ! purpose2 9 o!r cases ! co/ might v>y greatly ) local conditions4 ,! effici5cy ( ! transmission is measur$ by ! ratio ( ! en]gy deliv]$ by ! trans=m]s at ! receiv+ /ation = local di/ribution to ! en]gy deliv]$ by ! g5]at+ plant to ! trans=m]s t supply en]gy to ! l9e = transmission4 ,if work$ at full capacity ! l>ge trans=m]s "h consid]$ w\ld h an effici5cy ( ne>ly #ih p] c5t2 b z !y mu/ "w1 to "s ext5t1 on p>tial loads1 ! actual effici5cy w h>dly exce$ #if p] c5t4 ,! effici5cy ( ! l9e conductors rises on p>tial loads1 & may be safely tak5 at #ic p] c5t = all ( ! en]gy transmitt$1 ?\gh x is only #ij p] c5t on ! maximum load4 ,! comb9$ effici5cies ( ! two sets ( trans=m]s & ! l9e give ! effici5cy ( ! transmission1 :i* equals ! product ( #j4if #j4ic #j4if1 or almo/ exactly #he4g p] c5t4 ,9 o!r words1 ! trans=m]s at ! wat]-p[] /ation absorb #a4ag times z mu* en]gy z ! trans=m]s at ! receiv+ /ation deliv] to di/ribution l9es 9 ! place ( use4 ,int]e/1 ma9t5ance1 & depreciation ( ?is complete transmission sy/em are suffici5tly provid$ = by an all[ance ( #ae p] c5t ye>ly on its entire fir/ co/4 ,z ! total fir/ co/ ( ! transmission sy/em 0 f\nd to be #dde1jjj1 ! annual exp5se ( int]e/1 depreciation1 & repairs at #ae p] c5t ( ?is sum am\nts to #ff1gej4 ,9 ord] to f9d ! be>+s ( ?is annual *>ge on ! co/ ( p[] transmission ! total am\nt ( en]gy transmitt$ annually mu/ be det]m9$4 ,! #aj1jjj horse-p[] deliv]$ by ! sy/em at ! sub-/ation is simply ! maximum rate at :i* en]gy may be suppli$1 & ! elem5t ( "t mu/ be introduc$ 9 ord] to compute ! am\nt ( transmitt$ en]gy4 ,if ! sy/em c\ld be kept at "w dur+ tw5ty-f\r h\rs a day at full capacity1 ! deliv]$ en]gy w\ld be repres5t$ by ! product ( ! numb]s :i* /& = ! capacity & = ! total numb] ( h\rs ye>ly4 ,un=tunately1 h[ev]1 ! dem&s = electric light & p[] v>y ?r\gh a wide range 9 ! c\rse ( ea* tw5ty-f\r h\rs1 & ! p]iod ( maximum dem& ext5ds ov] only a small "p ( ea* day4 ,! problem is1 !re=e1 to f9d :at relation ! av]age load t may be _h dur+ ! tw5ty-f\r h\rs be>s to ! capacity requir$ to c>ry ?is maximum load4 ,z ! answ] to ?is "q dep5ds on ! p[] requirem5ts ( v>i\s classes ( consum]s1 x c be obta9$ only by exp]i5ce4 ,x has be5 f\nd t "s electric /ations1 work+ tw5ty-f\r h\rs daily on mix$ loads ( lamps & /ation>y motors1 c deliv] en]gy to an am\nt repres5t$ by ! necess>y maximum capacity dur+ ab\t #c1jjj h\rs p] ye>4 ,apply+ ?is rule to ! pres5t case1 ! trans=m]s at ! sub-/ation1 if load$ to _! maximum capacity ( #aj1jjj horse-p[] by ! heavie/ dem&s ( consum]s1 may be expect$ to deliv] en]gy to ! am\nt ( #c1jjj #aj1jjj #cj1jjj1jjj horse-p[] h\rs ye>ly4 ,! total co/ ( op]ation = ?is transmission sy/em 0 f\nd above to be #ff1gej p] annum1 exclusive ( ! co/ ( en]gy at ! g5]at+ plant4 ,?is sum1 divid$ by #cj1jjj1jjj1 %[s ! co/ ( en]gy transmission to be #j4bbb c5t p] horse-p[] h\r1 exclusive ( ! fir/ co/ ( ! en]gy4 ,to obta9 ! total co/ ( transmission1 ! figures j giv5 mu/ be increas$ by ! value ( ! en]gy lo/ 9 trans=m]s & 9 ! l9e conductors4 ,9 ord] to f9d ?is value1 ! co/ ( en]gy at ! g5]at+ plant mu/ be kn[n4 ,! co/ ( electrical en]gy at ! swit*bo>d 9 a wat]-p[] /ation is subject to wide v>iations1 ow+ to ! diff]5t inve/m5ts necess>y 9 ! hydraulic "w p] unit ( p[] develop$4 ,) l>ge p[]s1 su* z are "h consid]$1 a horse-p[] h\r ( electrical en]gy may be develop$ = mat]ially less ?an #j4e c5t 9 "s plants4 ,z ! av]age effici5cy ( ! pres5t transmission has be5 f\nd to be #he4g p] c5t ( ! en]gy deliv]$ by ! g5]ators1 x is evid5t t #a4ag horse-p[] h\rs mu/ be drawn f ! g5]ators = e horse-p[] h\r suppli$ by ! trans=m]s at ! sub-/ation = di/ribution4 ,9 o!r words1 #j4ag horse-p[] h\r is wa/$ = ea* horse-p[] h\r deliv]$4 ,! co/ ( #j4ag ( a horse-p[] h\r1 or say n m ?an #j4e #j4ag #j4jhe c5t1 mu/ ?us be add$ to ! figures = transmission co/ already f\nd1 t is1 #j4bbb c5t p] horse-p[] h\r1 to obta9 ! total co/ ( transmission4 ,! sum ( ^! two items ( co/ am\nts to #j4cjg c5t p] horse-p[] h\r1 z ! entire transmission exp5se4 ,x may n[ be ask$ h[ ! co/ ( transmission j f\nd w increase if ! di/ance be ext5d$4 ,z an illu/ration1 assume ! l5g? ( ! transmission to be #aej in/ead ( #ajj miles4 ,let ! am\nt ( en]gy deliv]$ by ! sub-/ation1 ! loss 9 l9e conductors1 & ! en]gy drawn f ! g5]at+ plant rema9 ! same z be=e4 ,evid5tly ! co/ ( ! pole l9e w be increas$ #ej p] c5t1 t is1 f #gj1jjj to #aje1jjj4 ,trans=m]s1 hav+ ! same capacity1 w n be *ang$ f ! previ\s e/imate ( #aej1jjj4 ,if ! voltage ( ! transmission rema9 con/ant1 z well z ! l9e loss at maximum load1 ! weight & co/ ( copp] conductors mu/ increase ) ! squ>e ( ! di/ances ( transmission4 ,= #aej miles ! weight ( copp] w ?us be #b4be times ! weight requir$ = ! #ajj-mile transmission4 ,in/ead ( an increase 9 ! weight ( conductors a high] voltage may be adopt$4 ,! trans=m]s = ! two great transmission sy/ems t ext5d ov] a di/ance ( ab\t #aej miles1 f ! ,si]ra ,nevada ,m\nta9s to ,san ,francisco ,bay1 9 ,cali=nia1 are design$ to deliv] en]gy to ! l9e at ei!r #dj1jjj or #fj1jjj volts1 z desir$4 ,?\gh ! regul> op]ation at fir/ 0 at ! l[] pressure1 ! voltage has be5 rais$ to #fj1jjj4 ,! l[] valleys ( ! ,sacram5to & ! ,san ,joaqu9 riv]s1 :i* are cross$ by ^! ,cali=nia sy/ems1 z well z ! %ores ( ,san ,francisco ,bay1 h z mu* annual precipitation & z moi/ an atmosph]e z mo/ p>ts ( ! ,unit$ ,/ates & ,canada4 ,!re=e !re seems to be no good reason to prev5t ! use ( #fj1jjj volts else:]e4 ,! di/ance ov] :i* en]gy may be transmitt$ at a giv5 rate1 ) a fix$ p]c5tage ( loss & a con/ant weight ( copp]1 goes up directly ) ! voltage employ$4 ,?is rule foll[s because1 :ile ! weight ( conductors to transmit en]gy at a giv5 rate1 ) a c]ta9 p]c5tage ( loss & con/ant voltage1 increases z ! squ>e ( ! di/ance1 ! weight ( conductors decreases z ! squ>e ( ! voltage :5 all ! o!r factors are con/ant4 ,apply+ ^! pr9ciples to ! #aej-mile transmission1 x is evid5t t an increase ( ! voltage to #fj1jjj w all[ ! weight ( conductors to rema9 exactly :]e x 0 = ! transmission ( #ajj miles1 ! rate ( work+ & ! l9e loss be+ equal = ! two cases4 ,! only additional item ( exp5se 9 ! #aej-mile transmission1 on ! basis ( #fj1jjj volts1 is ! #ce1jjj = pole l9e4 ,all[+ #ae p] c5t on ! #ce1jjj to cov] int]e/1 depreciation1 & ma9t5ance1 z be=e1 makes a total ye>ly increase 9 ! co/s ( transmission ( #e1bej ov] t f\nd = ! transmission ( #ajj miles4 ,?is la/ sum am\nts to #j4jage c5t p] horse-p[] h\r ( ! deliv]$ en]gy4 ,! co/ ( transmission is ?us rais$ to #j4cjg #j4jage #j4cbd c5t p] horse-p[] h\r ( deliv]$ en]gy on ! #aej-mile sy/em ) #fj1jjj volts4 ,exi/+ transmission l9es n only illu/rate ! relations ( ! factors nam$ above to ! co/ & weight ( conductors1 b also %[ m>k$ v>iations ( practice1 correspond+ to ! op9ions ( diff]5t eng9e]s4 ,9 ord] to br+ out ! facts on ^! po9ts1 ! data ( a numb] ( transmission l9es are "h pres5t$4 ,on ^! l9es ! di/ance ( transmission v>ies betwe5 #e & #adb miles1 ! voltage f #e1jjj to #ej1jjj1 & ! maximum rate ( "w f a few hundr$ to "s ?\s&s ( horse-p[]4 ,= ea* transmission ! s+le l5g? & total weight ( conductors1 ! voltage1 & ! capacity ( ! g5]at+ equipm5t t supplies ! l9e is record$4 ,f ^! data ! volts p] mile ( l9e1 weight & co/ ( conductors p] kil[att capacity ( g5]at+ equipm5t1 & ! weight ( conductors p] mile = ea* kil[att ( capacity 9 ! g5]at+ equipm5t are calculat$4 ,9 ea* case ! l5g? ( l9e giv5 is ! di/ance f ! g5]at+ to ! receiv+ /ation4 ,! capacity giv5 = g5]at+ equipm5t 9 ea* case is t ( ! ma9 dynamos1 :]e _! entire output goes to ! transmission l9e 9 "q1 b :]e ! dynamos supply en]gy = o!r purposes also1 ! rat+ ( ! trans=m]s t fe$ only ! p>ticul> transmission l9e is giv5 z ! capacity ( g5]at+ equipm5t4 ,,di/ance ,,& ,,voltage ,,( ,,electrical ,,transmission4 ---------------------------------------- ------------------------ ,di/ance 9 ,volts4 ,volts p] ,miles4 ,mile4 ---------------------------------------- ------------------------ ,colgate to ,oakl&1 ,cal4 #adb #fj1jjj #dbb ,caon ,f]ry to ,butte1 ,mont4 #fe #ej1jjj #gfi ,santa ,ana ,riv] to ,los ,angeles #hc #cc1jjj #cig ,ogd5 to ,salt ,lake ,city1 ,utah #cf4e #af1jjj #dch ,madrid to ,bl&1 ,n4 ,m4 #cb #bj1jjj #fbe ,well& ,canal to ,hamilton1 ,c4 #ce #bb1ejj #fdc #cg ,san ,gabriel ,caon to ,los ,angeles #bc #af1jjj #fie ,caon ,city to ,cripple ,creek1 ,colo4 #bc4e #bj1jjj #hea ,apple ,riv] to ,/4 ,paul1 ,m9n4 #be #be1jjj #a1jjj ,yadk9 ,riv] to ,salem1 ,n4 ,c4 #ad4e #ab1jjj #hbg ,into ,victor1 ,colo4 #h #ab1fjj #a1ege ,montmor5cy ,falls to ,quebec #g #e1ejj #ghe ,f>m+ton ,riv] to ,h>t=d #aa #aj1jjj #iji ,sewall's ,falls to ,r4,r4 %ops ,concord #e4e #aj1jjj #a1hah ,wilbraham to ,ludl[ ,mills #d4e #aa1ejj #b1eee ,to ,dales1 ,ore4 #bg #bb1jjj #had ---------------------------------------- ------------------------ ,! transmission sy/ems "h consid]$ h be5 select$ because x 0 possible to obta9 ! desir$ data z to ea*1 & x may be presum$ t !y fairly illu/rate pres5t practice4 ,x may be not$ at once t 9 g5]al ! l9e voltage is increas$ ) ! l5g? ( ! transmission4 ,?us1 ! transmission = ! ,ludl[ ,mills ov] a di/ance ( #d4e miles is c>ri$ out at #aa1ejj volts4 ,on ! o!r h&1 ! transmission betwe5 ,caon ,f]ry & ,butte1 a di/ance ( #fe miles1 employs #ej1jjj volts & repres5ts rec5t practice4 ,! sy/em f ,colgate to ,oakl&1 a di/ance ( #adb miles1 ! longe/ "h consid]$1 n[ has #fj1jjj volts on its l9es4 ,9 spite ( ! g5]al resort to high pressures ) great] di/ances ( transmission1 ! rise 9 voltage has n kept pace ) ! increas+ l5g? ( l9e4 ,= ! ,wilbraham-,ludl[ transmission ! total pressure am\nts to #b1eee volts p] mile1 :ile ! l9e f ,colgate to ,oakl& ) #ca4e times ! l5g? ( ! =m] op]ates at an av]age ( only #dbb volts p] mile4 ,( ! fifte5 transmissions consid]$1 six are ov] di/ances ( less ?an #ae miles1 & = f\r ( ! six ! voltage is m ?an #ijj p] mile4 ,eight transmissions range f #bc to #hc miles 9 l5g?1 ) voltages t av]age betwe5 #a1jjj volts p] mile at #be miles & only #cig p] mile on ! #hc-mile l9e4 ,! volts p] mile are #f times z great 9 ! ,ludl[ z 9 ! ,oakl& transmission4 ,,capacity ,,( ,,g5]at+ ,,/ations ,,& ,,weight ,,( ,,conductors4 ---------------------------------------- ---------------------------- ,kil[att ,total ,weight ,p\nds ( ,capacity at ( ,conductors ,location ( ,transmission4 ,g5]ators4,conductors4 p] ,kil[att ,capacity4 ---------------------------------------- ---------------------------- ,wilbraham to ,ludl[ #d1fjj #ag1hbj #c4g;,a ,sewall's ,falls to railroad %ops #ej #f1iad #ae ,into ,victor1 ,colo4 #a1fjj #ae1ifj #aj ,to ,dales1 ,ore4 #a1jjj #cc1ici #cd ,apple ,riv] to ,/4 ,paul #c1jjj #aei1fjj #ec ,f>m+ton ,riv] to ,h>t=d #a1ejj #ed1jed #cf ,caon ,city to ,cripple ,creek #a1ejj #ei1jgi #ci ,yadk9 ,riv] to ,salem #a1ejj #eh1jgc #ci ,montmor5cy ,falls to ,quebec #b1djj #ahi1jef #gi ,caon ,f]ry to ,butte #e1gjj #feh1cbj #aae ,san ,gabriel ,caon to ,los ,angeles #a1bjj #gc1jjb #fa ,well& ,canal to ,hamilton #f1jjj #cgf1did #fc ,madrid to ,bl&1 ,n4 ,m4 #fjj #abg1fhj #bab ,ogd5 to ,salt ,lake ,city #b1bej #bib1cfe #abi ,santa ,ana ,riv] to ,los ,angeles #b1bej #ffd1hcj #bie ,colgate to ,oakl& #aa1bej #ijf1ied #ha #ddf1fbg #dj;,a ---------------------------------------- ---------------------------- ,a ,alum9um4 ,^! wide v>iations 9 ! volts p] mile on transmission l9es & 9 l5g? ( l9es lead to diff]5t weights ( conductors p] kil[att ( g5]ator capacity4 ,all o!r factors rema9+ con/ant1 ! weight ( conductors p] kil[att ( g5]ator capacity w\ld be ! same :atev] ! l5g? ( ! transmission1 provid$ t ! volts p] mile 7 uni=m = all cases4 ,"o important factor1 ! p]c5tage ( loss = :i* ! l9e conductors are design$ at full load1 is sure to v>y 9 diff]5t cases1 & lead to correspond+ v>iations 9 ! weights ( conductors p] kil[att ( g5]ator capacity4 ,9 conductors ( equal l5g? "o p\nd ( alum9um has ne>ly ! same electrical resi/ance z two p\nds ( copp]1 & ?is ratio mu/ be all[$ = :5 copp] & alum9um l9es are comp>$4 ,f ! table x may be se5 t ! weight ( conductors p] kil[att ( g5]ator capacity = ! transmission f ,santa ,ana ,riv] is #bi4e times z great z ! l weight = ! l9e into ,victor4 ,b ! volts p] mile are f\r times z great on ! ,victor z !y are on ! ,santa ,ana ,riv] l9e4 ,! extreme range ( ! cases pres5t$ is t betwe5 ! ,ludl[ plant1 ) ! equival5t ( #g4d p\nds1 & ! ,santa ,ana ,riv] sy/em ) #bie p\nds ( copp] conductors p] kil[att ( g5]ator capacity4 ,?ree transmissions ) #a1ege to #b1eee volts p] mile h ! equival5t ( #g4d to #ae p\nds ( copp] ea*1 p] kil[att ( g5]ator capacity4 ,,weight ,,& ,,co/ ,,( ,,conductors4 ---------------------------------------- ------------- ,p\nds p],doll>s p] ,kil[att ,g5]ator ,mile4 ,kil[att4 ---------------------------------------- ------------- ,wilbraham to ,ludl[ #j4hf;,a #a4aa ,sewall's ,falls to railroad %ops #b4g #b4be ,into ,victor1 ,colo4 #j4i #a4ej ,to ,dales1 ,ore4 #a4b #e4aj ,apple ,riv] to ,/4 ,paul #b4a #g4ie ,f>m+ton ,riv] to ,h>t=d #c4b #aj4hj ,caon ,city to ,cripple ,creek #a4f #e4he ,yadk9 ,riv] to ,salem #b4f #e4he ,montmor5cy ,falls to ,quebec #aa4b #aa4he ,caon ,f]ry to ,butte #a4g #ag4be ,san ,gabriel ,caon to ,los ,angeles #b4f #i4he ,well& ,canal to ,hamilton #a4g #i4de ,madrid to ,bl&1 ,n4 ,m4 #f4f #ca4hj ,ogd5 to ,salt ,lake ,city #c4e #ai4ce ,santa ,ana ,riv] to ,los ,angeles #c4e #dd4be ,colgate to ,oakl& 4#ef #bd4ae 4#bg;,a ---------------------------------------- ------------- ,a ,alum9um4 ,( ! sev5 transmissions us+ betwe5 #cf & #gi p\nds ( copp] = ea* kil[att ( g5]ator capacity1 f\r h voltages rang+ f #hbg to #a1jjj p] mile1 & on only "o is ! pressure z l[ z #fdc volts p] mile4 ,five transmission l9es v>y betwe5 #aae & #bie p\nds ( copp]1 or its equival5t1 p] kil[att ( g5]ator capacity1 & _! voltages p] mile are z high z #gfi 9 "o case & d[n to #bha 9 ano!r4 ,all[+ = "s v>iations 9 ! p]c5tages ( loss 9 transmission l9es at full load1 ! fifte5 plants pla9ly illu/rate ! advantage ( a high voltage p] mile1 z to ! weight ( conductors4 ,?is advantage is especially cle> if ! diff]5ces due to ! l5g?s ( ! transmissions are elim9at$ by divid+ ! weight ( conductors p] kil[att ( g5]ator capacity 9 ea* case by ! l5g? ( ! transmission 9 miles4 ,?is division gives ! weight ( conductors p] kil[att ( g5]ators = ea* mile ( ! l9e1 :i* may be call$ ! weight p] kil[att mile4 ,= ! ,ludl[ transmission ?is weight is only #j4hf p\nd ( alum9um1 ! equival5t ( #a4gb p\nds ( copp]1 :ile ! l weight = ! l9e into ,quebec is #aa4b p\nds ( copp]1 or #f4e times t = ! =m] l9e4 ,b ! voltage p] mile on ! ,ludl[ is #c4b times z great z ! l voltage on ! ,quebec l9e4 ,! weight ( conductor p] kil[att mile 9 ! ,victor l9e is only #j4i p\nd1 & ! l weight = ! l9e betwe5 ,madrid & ,bl& is #f4f p\nds1 or #g4c times z great4 ,on ! ,victor l9e ! voltage p] mile is #b4e times z great z ! voltage = ea* mile ( ! ,bl& l9e4 ,comp>+ sy/ems ) ne>ly equal voltages p] mile1 x appe>s 9 mo/ cases t only su* diff]5ce exi/s 9 _! p\nds ( conductors p] kil[att mile z may readily be acc\nt$ = by designs = v>i\s p]c5tages ( loss at full load4 ,?\gh ! transmission l9e into ,butte is ne>ly twice z long z ! "o ent]+ ,hamilton1 ! weight ( conductors = ea* is #a4g p\nds p] kil[att mile4 ,! l9e f ,santa ,ana ,riv] is m ?an twice z long z ! "o ent]+ ,salt ,lake ,city1 b its voltage p] mile is only n9e p] c5t less1 & !re are #c4e p\nds ( copp] 9 ea* l9e p] kil[att mile4 ,! f9al1 practical que/ions z to conductors 9 electrical transmission relate to _! co/ p] kil[att ( maximum work+ capacity1 & p] kil[att h\r ( deliv]$ en]gy4 ,if ! co/ ( conductors p] kil[att ( g5]ator capacity is great] ?an t ( all ! rema9+ equipm5t1 x is d\btful :e!r ! transmission w pay4 ,if fix$ *>ges on ! conductors m ?an (fset ! diff]5ce 9 ! co/ ( en]gy p] kil[att h\r at ! po9ts ( developm5t & deliv]y1 x is c]ta9 t ! g5]at+ plant %\ld be locat$ :]e ! p[] is want$4 ,! great co/ ( conductors is (t5 put =w>d z a mo/ s]i\s imp$im5t to long-di/ance transmission1 & ! examples "h cit$ w indicate ! weight ( ?is argum5t4 ,9 ord] to f9d ! approximate co/ ( conductors p] kil[att ( g5]ator capacity = ea* ( ! transmission l9es "h consid]$1 ! price ( b>e copp] wire is tak5 at #ae c5ts1 & ! price ( b>e alum9um wire at #cj c5ts p] p\nd4 ,9 ea* case ! weight ( copp] or alum9um conductor p] kil[att ( g5]ator capacity is us$ to det]m9e _! co/s p] kil[att ( ?is capacity at ! prices j nam$4 ,?is process :5 c>ri$ out = ! #ae transmission l9es %[s t _! co/ ( conductors p] kil[att ( g5]ator capacity v>ies betwe5 #a4aa = ! #d4e mile l9e into ,ludl[ & #dd4be = ! l9e ( #hc miles f ! ,santa ,ana ,riv]4 ,x %\ld be not$ t ! =m] ( ^! l9es op]ates at #b1eee & ! latt] at #cig volts p] mile4 ,! l9e into ,madrid %[s an inve/m5t 9 conductors ( #ca4hj p] kil[att ( g5]ator capacity ) #fbe volts p] mile4 ,t a long transmission does n necess>ily require a l>ge inve/m5t 9 conductors p] kil[att ( g5]ator capacity is %[n by ! l9e #fe miles long into ,butte1 = :i* ! co/ is #ag4be p] kil[att1 ) #gfi volts p] mile4 ,= ! transmission to ,/4 ,paul1 a di/ance ( #be miles1 at #a1jjj volts p] mile1 ! co/ ( conductors is #g4ie p] kil[att ( g5]ator capacity4 ,! sev5-mile l9e into ,quebec %[s an inve/m5t ( #aa4he p] kil[att ( g5]ator capacity4 ,,*apt] ,,iv4 ,,advantages ,,( ,,! ,,cont9u\s ,,& ,,alt]nat+ ,,curr5t4 ,electrical transmissions ov] long di/ances 9 ,am]ica h be5 ma9ly c>ri$ out ) alt]nat+ curr5t4 ,9 ,europe1 on ! o!r h&1 cont9u\s curr5t is widely us$ on long transmissions at high voltages4 ,s radical a diff]5ce 9 practice seems to indicate t nei!r sy/em is lack+ 9 po9ts ( sup]iority4 ,a fundam5tal feature ( long transmissions is ! high voltage necess>y = economy 9 conductors1 & ?is voltage is atta9$ by entirely diff]5t me?ods ) cont9u\s & alt]nat+ curr5ts4 ,9 dynamos ( sev]al hundr$ or m kil[atts capacity ! pressure ( cont9u\s curr5t has n ?us f> be5 pu%$ above #d1jjj volts1 because ( ! dang] ( sp>k+ & fla%+ at ! commutator4 ,:]e #aj1jjj or m volts are requir$ on a transmission l9e ) cont9u\s curr5t a numb] ( dynamos are connect$ 9 s]ies s t ! voltage ( ea* is add$ to t ( ! o!rs4 ,9 ?is way ! voltage ( ea* dynamo may be z l[ z is ?\ght desirable )\t limit+ ! total l9e voltage4 ,!re is no app>5t limit to ! numb] ( cont9u\s-curr5t dynamos t may be op]at$ 9 s]ies or to ! voltage t may be ?us obta9$4 ,9 ! rec5tly complet$ transmission f ,/4 ,maurice to ,lausanne1 ,switz]l&1 ) cont9u\s curr5t1 t5 dynamos are connect$ 9 s]ies to secure ! l9e voltage ( #bc1jjj4 ,:5 occasion requires tw5ty or ?irty or m dynamos to be op]at$ 9 s]ies1 giv+ #ej1jjj or #ge1jjj volts on ! l9e1 ma*9es exactly l ^? 9 ! transmission j nam$1 may be us$4 ,no matt] h[ _m ( ^! dynamos are op]at$ 9 s]ies ! electric /ra9 on ! insulation ( ! w9d+s ( ea* dynamo rema9s practically con/ant1 because ! iron frame ( ea* dynamo is insulat$ 9 a mo/ sub/antial mann] f ! gr\nd4 ,! electric /ra9 on ! insulation ( ! w9d+s ( ea* dynamo 9 ! s]ies is ?us limit$ to ! voltage g5]at$ by t dynamo4 ,!re is no practical limit to ! ?ickness or /r5g? ( ! insulation t may be int]pos$ betwe5 ! frame ( ea* dynamo & ! gr\nd1 & h5ce no limit to l9e voltage z f> z dynamo insulation is conc]n$4 ,x is impracticable to op]ate alt]nat+ dynamos 9 s]ies s z to add _! voltages1 & ! pressure available 9 transmission ) alt]nat+ curr5t mu/ be t ( a s+le dynamo or mu/ be obta9$ by ! use ( trans=m]s4 ,! voltage ( an alt]nat+ may be c>ri$ mu* high] ?an t ( a cont9u\s-curr5t dynamo ( v l>ge capacity1 & 9 _m cases pressures ( #ac1bjj volts are n[ suppli$ to transmission l9es by alt]nat+ dynamos4 ,j h[ high ! voltage ( s+le alt]nat+ dynamos w be c>ri$ no "o c say1 b x seems probable t ! practical limit w prove to be mu* less ?an ! voltages n[ employ$ 9 "s transmissions4 ,z ! voltage ( alt]nat+ dynamos is c>ri$ high] ! ?ickness ( insulation on _! armature coils & consequ5tly ! size or numb] ( slots 9 _! armature cores & ! size ( ^! cores increase rapidly4 ,! dim5sions & weight ( an alt]nat+ dynamo p] unit ( its capacity ?us g up ) ! voltage1 & at "s undet]m9$ po9t ! co/ ( ! high-voltage dynamo is great] ?an t ( a l[-voltage dynamo ( equal capacity ) rais+ trans=m]s4 ,to ! voltage t may be suppli$ by trans=m]s !re is no practical limit n[ 9 sight4 ,l9es h be5 9 regul> op]ation f "o to sev]al ye>s on :i* trans=m]s supply #dj1jjj to #ej1jjj volts2 "s l>ge trans=m]s h be5 built = comm]cial use at #fj1jjj volts1 & o!r trans=m]s = exp]im5tal & te/+ purposes h be5 employ$ 9 a numb] ( cases = pressures ( #ajj1jjj volts & m4 ,available voltages = cont9u\s- & alt]nat+-curr5t transmissions are ?us on a practically equal foot+ z to _! upp] limit4 ,! am\nt ( p[] t may be g5]at$ & deliv]$ ) ei!r ! alt]nat+- or cont9u\s-curr5t sy/em ( transmission is practically unlimit$4 ,s+le alt]nat+ dynamos may be _h ( #e1jjj or ev5 #h1jjj kil[atts capacity if desir$1 b x is seldom t ^! v l>ge units are employ$1 because ! capacity ( a g5]at+ /ation %\ld be divid$ up among a numb] ( ma*9es4 ,x is p]haps impracticable to build s+le cont9u\s-curr5t dynamos ) capacities equal to ^? ( ! l>ge/ alt]nators1 b z any numb] ( ! cont9u\s-curr5t ma*9es may be op]at$ ei!r 9 s]ies or multiple1 ! p[] t may be appli$ to a transmission circuit is unlimit$4 ,at ! plant or plants :]e ! p[] transmitt$ by cont9u\s curr5t is receiv$1 a numb] ( motors mu/ be connect$ 9 s]ies to op]ate at ! high-l9e voltage4 ,^! motors may all be locat$ 9 a s+le room1 may be connect$ to ma*9]y 9 diff]5t p>ts ( a build+1 or may be 9 use at po9ts miles ap>t4 ,! vital requirem5t is t ! motors mu/ be 9 s]ies ) ea* o!r s t ! l9e voltage divides betwe5 !m4 ,if simply me*anical p[] is want$ at ! places :]e ! motors are locat$1 !y complete ! transmission sy/em & no fur!r electrical app>atus is requir$4 ,:]e1 h[ev]1 z at ,lausanne1 ! transmitt$ p[] is to be us$ 9 a sy/em ( g5]al electrical supply1 ! motors t receive ! curr5t at ! l9e voltage mu/ drive dynamos t w deliv] en]gy ( ! requir$ sorts4 ,9 ! /ation at ,lausanne f\r ( ! motors to :i* ! transmission l9e is connect$ ea* drives a #c1jjj-volt ?ree-phase alt]nator = ! di/ribution ( light & p[]4 ,! fif? motor at ?is /ation drives a #fjj-volt dynamo :i* deliv]s cont9u\s curr5t to a /reet railway4 ,a six? motor 9 ! same s]ies drives a cem5t factory "s di/ance f ! /ation4 ,neglect+ m9or *anges 9 capacity due to losses 9 ! l9e & motors1 ?is cont9u\s-curr5t sy/em mu/ ?us include ?ree kil[atts 9 motors & dynamos = ea* kil[att deliv]$ = g5]al electrical di/ribution at ! receiv+ /ation4 ,9 a case 9 :i* only me*anical p[] is want$ at ! receiv+ /ation1 ! dynamos & motors conc]n$ 9 ! transmission mu/ h a comb9$ capacity ( two horse-p[] = ea* horse-p[] deliv]$ at ! motor %aft4 ,9 contra/ ) ^! figures1 ! electrical equipm5t 9 a transmission ) alt]nat+ curr5t = me*anical p[] alone includes two kil[atts capacity 9 g5]ators & motors1 besides two kil[atts capacity 9 trans=m]s = ea* correspond+ unit ( p[] deliv]$ at ! motor %aft unless g5]ators & motors op]ate at ! full l9e voltage4 ,if a g5]al electrical supply is to be op]at$ by ! alt]nat+ sy/em ( transmission1 ei!r motors & dynamos or rot>y conv]t]s mu/ be add$ to trans=m]s :]e cont9u\s curr5t is requir$4 ,an alt]nat+ transmission may ?us include z little z "o kil[att 9 dynamos & "o 9 trans=m]s1 or z mu* z two kil[atts capacity 9 dynamos1 two 9 trans=m]s1 & "o 9 motors = ea* kil[att deliv]$ to di/ribution l9es at ! receiv+ /ation4 ,l9e con/ruction f ! cont9u\s-curr5t transmission is ( ! mo/ simple "* ap>t f ! necessity ( high insulation4 ,only two wires are necess>y & !y may be ( any desir$ cross-section1 /rung on a s+le pole l9e & ne$ n be transpos$4 ,on ^! wires ! maximum voltage = :i* insulation mu/ be provid$ is ! nom9al voltage ( ! sy/em4 ,x is possible "u ^! conditions to build a s+le transmission l9e ) two conductors ( su* size & /r5g? & at su* a di/ance ap>t t a high degree ( reliability is atta9$ aga9/ breaks 9 ! wires or arc+ betwe5 !m4 ,9 a transmission ( p[] by two- or ?ree-phase alt]nat+ curr5t at lea/ ?ree wires are necess>y & six or m are (t5 employ$4 ,if six or m wires c>ry+ curr5t at ! high voltages requir$ by long transmissions are m\nt$ on a s+le l9e ( poles1 x is n practicable to obta9 su* di/ances betwe5 ! wires z are desirable4 ,! repair ( "o set ( wires :ile ! o!r set is 9 op]ation is a dang]\s task1 & an arc orig9at+ betwe5 "o set ( ! wires is apt to be communicat$ to ano!r set4 ,= ^! reasons two pole l9es are frequ5tly provid$ = a transmission ) alt]nat+ curr5t1 & ?ree or m wires are !n erect$ on ea* l9e4 ,comp>$ ) a cont9u\s-curr5t transmission1 "o ) alt]nat+ curr5t (t5 requires m poles & is q c]ta9 to require m cross-arms1 p9s1 insulators1 & labor ( erection4 ,= a giv5 effective voltage ( transmission x is h>d] to insulate an alt]nat+- ?an a cont9u\s-curr5t l9e4 ,9 ! fir/ place ! maximum voltage ( ! alt]nat+ l9e ) ev5 a true s9e curve ( pressure is #a4d times ! nom9al effective voltage1 b ! insulation mu/ )/& ! maximum pressure4 ,!n comes ! matt] ( resonance1 :i* may c>ry ! maximum voltage ( an alt]nat+ circuit up to sev]al times its normal am\nt1 if ! p]iod ( electrical vibration = t p>ticul> circuit %\ld correspond to ! frequ5cy ( ! dynamos t op]ate x4 ,ev5 :]e ! vibration p]iod ( a transmission circuit & ! frequ5cy ( its dynamos d n correspond1 & good con/ruction %\ld always be plann$ = ?is lack ( agreem5t1 resonance may & (t5 does increase ! normal voltage ( an alt]nat+ transmission by a l>ge p]c5tage4 ,! alt]nat+ sy/em ( transmission mu/ "w at practically con/ant voltage :atev] ! /ate ( its load1 s t ! normal /ress on ! insulation is always at its maximum4 ,9 a transmission ) cont9u\s curr5t on ! o!r h&1 if ! prevail+ practice ( a con/ant curr5t & v>y+ pressure on ! l9e is foll[$1 ! insulation is subject to ! highe/ voltage only at times ( maximum load on ! sy/em4 ,lightn+ is a v real & press+ dang] to ma*9]y connect$ to long transmission l9es1 & ?is dang] is mu* h>d] to gu>d aga9/ 9 an alt]nat+ sy/em ?an 9 a sy/em ) cont9u\s con/ant curr5t4 ,! l>ge degree ( exemption f damage by lightn+ enjoy$ by s]ies arc dynamos is well kn[n1 ! magnet w9d+s ( su* ma*9es act+ z an inductance t t5ds to keep lightn+ out ( !m4 ,moreov]1 ) any cont9u\s-curr5t ma*9es lightn+ arre/]s hav+ l>ge self-induction may be connect$ 9 circuit & =m a mo/ effective safegu>d aga9/ lightn+1 b ?is plan is n practicable on alt]nat+ l9es4 ,9 ! matt] ( swit*es1 controll+ app>atus1 & swit*bo>ds1 an alt]nat+ transmission requires mu* m equipm5t ?an a sy/em us+ cont9u\s1 con/ant curr5t4 ,! t5 dynamos 9 ! g5]at+ /ation at ,/4 ,maurice1 ) a capacity ( #c1dej kil[atts at #bc1jjj volts1 are ea* connect$ & disconnect$ ) ! transmission by a swit* 9 a small circul> column ( ca/-iron t /&s h>dly brea/ high4 ,an amp]emetre & voltmetre are m\nt$ on ea* dynamo4 ,! alt]nat+ g5]ators 9 a /ation ( equal capacity & voltage w\ld require a l>ge swit*bo>d fitt$ ) bus-b>s1 oil swit*es1 & automatic circuit-break]s4 ,relative effici5cies = ! cont9u\s-curr5t & ! alt]nat+-transmission sy/ems v>y ) ! k9d ( s]vice requir$ at receiv+ /ations & ) ! ext5t to :i* trans=m]s are us$ 9 ! alt]nat+ sy/em1 o!r factors be+ con/ant4 ,= purposes ( comp>ison ! effici5cy at full load ( bo? alt]nat+- & cont9u\s-curr5t dynamos & motors1 also ( rot>y conv]t]s1 may be fairly tak5 at #ib p] c5t1 & ! effici5cy ( trans=m]s at #if p] c5t4 ,= ! l9e an effici5cy ( #id p] c5t may be assum$ at full load1 ?is be+ ! actual figure 9 "o ( ! ,swiss transmissions ( #b1afj kil[atts at #ad1djj volts to a di/ance ( #cb miles4 ,:]e ! cont9u\s curr5t sy/em mu/ simply deliv] me*anical p[] at ! receiv+ /ations1 its effici5cy "u full load am\nts to #ib 4#id 4#ib #gi4fe p] c5t f dynamo %aft to motor %aft4 ,an alt]nat+ sy/em deliv]+ me*anical p[] w h an effici5cy ( #ib 4#id 4#if 4#ib #gf4df p] c5t betwe5 dynamo %aft & motor %aft1 if ! l9e voltage is g5]at$ 9 ! armature coils ( ! dynamo & ! l9e loss is #f p] c5t4 ,if /ep-up trans=m]s are employ$ to secure ! l9e voltage ! effici5cy ( ! alt]nat+ transmission deliv]+ me*anical p[] drops to ! figure ( #ib 4#if 4#id 4#if 4#ib #gc4dj p] c5t4 ,x ?us appe>s t = ! simple deliv]y ( me*anical p[] ! cont9u\s curr5t transmission has an advantage ov] ! alt]nat+ ( ?ree to six p] c5t 9 effici5cy1 dep5d+ on :e!r /ep-up trans=m]s are employ$4 ,:5 ! receiv+ /ation mu/ deliv] a supply ( ei!r cont9u\s or alt]nat+ curr5t = g5]al di/ribution1 ! effici5cy ( ! cont9u\s-curr5t transmission am\nts to #ib 4#id 4#ib 4#ib #gc4bg p] c5t4 ,! alt]nat+-transmission sy/em 9 a case 9 :i* no /ep-up trans=m]s are employ$ w deliv] alt]nat+ curr5t ( ! same frequ5cy z t on ! transmission l9e at any desir$ pressure = g5]al di/ribution at an effici5cy ( #ib 4#id 4#if #hc4jb p] c5t1 if /ep-d[n trans=m]s are us$1 b ! effici5cy drops to #hc4jb 4#if #gi4gj p] c5t4 :5 /ep-up trans=m]s are introduc$4 ,if ! alt]nat+ transmission uses no /ep-up trans=m]s & deliv]s ei!r alt]nat+ or cont9u\s curr5t by means ( motor g5]ators1 its effici5cy at full load is #hc4jb 4#ib 4#ib #gj4bf p] c5t1 b ) /ep-up trans=m]s add$ ! effici5cy drops to #gj4bf 4#if #fg4dc p] c5t4 ,9 a transmission :]e electrical en]gy mu/ be deliv]$ = g5]al di/ribution1 ! full-load effici5cy ( an alt]nat+ sy/em ranges ei!r high] or l[] ?an t ( a cont9u\s-curr5t sy/em dep5d+ on :e!r ! curr5t f ! transmission l9e mu/ be conv]t$ or n4 ,l9e loss is ! same :atev] ! load 9 a con/ant-curr5t transmission1 s t l9e effici5cy falls r rapidly ) ! load4 ,on ! o!r h&1 at con/ant pressure ! p]c5tage ( en]gy loss on ! l9e v>ies directly ) ! load1 b ! actual rate ( en]gy loss ) ! squ>e ( ! load4 ,on p>tial loads ! l9e effici5cy is ?us mu* high] ) alt]nat+ ?an ) cont9u\s con/ant curr5t4 ,effici5cy ( electrical ma*9]y is g5]ally l[ at p>tial loads1 s t 9 cases 9 :i* ! numb] or capacity ( alt]nat+ dynamos1 trans=m]s1 motors1 or rot>y conv]t]s = a transmission w\ld be great] p] unit ( deliv]$ p[] ?an ! correspond+ numb] or capacity ( ma*9es = a transmission by cont9u\s curr5t1 ! latt] w\ld probably h ! advantage 9 ! comb9$ effici5cy ( ma*9]y at p>tial loads4 ,9 ?is way ! l[]-l9e effici5cy ( "o sy/em might (fset ! l[] effici5cy ( ma*9]y 9 ! o!r4 ,en]gy is usually v *eap at ! g5]at+ /ation ( a transmission sy/em4 ,= ?is reason small diff]5ces 9 ! effici5cies ( diff]5t sy/ems %\ld be giv5 only mod]ate weight 9 comp>ison ) ! items ( fir/ co/1 reliability1 & exp5se ( op]ation4 ,9 ! matt] ( fir/ co/ at lea/ ! cont9u\s-curr5t sy/em seems to h a di/9ct advantage ov] ! alt]nat+4 ,)\t go+ into a detail$ e/imate1 x is in/ructive to consid] ! figures giv5 by a body ( five eng9e]s select$ to report on ! co/ ( cont9u\s- & alt]nat+-curr5t equipm5ts = ! ,/4 ,maurice & ,lausanne transmission4 ,accord+ to ! report ( ^! eng9e]s1 a ?ree-phase transmission sy/em w\ld h co/ #adj1jjj m ?an ! cont9u\s-curr5t sy/em actually in/all$1 all o!r factors rema9+ con/ant4 ,x %\ld be not$ t ! conditions ( ?is transmission are favorable to ?ree-phase work+ & unfavorable to cont9u\s-curr5t equipm5t1 because all ( ! en]gy except t go+ to ! #djj horse-p[] motor at ! cem5t mill mu/ be deliv]$ at ! receiv+ /ation = g5]al di/ribution4 ,moreov]1 f\r out ( ! five motors at ,lausanne drive ?ree-phase g5]ators1 & only "o drives a cont9u\s-curr5t dynamo = ! electric railway1 s t a ?ree-phase transmission w\ld h requir$ only "o rot>y conv]t]4 ,_h ! transmission be5 conc]n$ m]ely ) ! deliv]y ( me*anical p[]1 z at ! cem5t mill1 ! advantage ( ! cont9u\s- ov] ! alt]nat+-curr5t sy/em 9 ! matt] ( fir/ co/ w\ld h be5 mu* great] ?an x 04 ,long-di/ance transmission ) ?ree-phase curr5t began at ,frank=t1 9 #ahia1 :5 #eh kil[atts 7 receiv$ ov] a #be1jjj-volt l9e f ,lauff51 #aji miles away4 ,%ortly aft] ?is hi/oric exp]im5t1 ?ree-phase transmission 9 ! ,unit$ ,/ates began on a comm]cial scale1 & plants ( ?is sort h multipli$ rapidly "h4 ,meantime v little has be5 done 9 ,am]ica ) cont9u\s curr5ts 9 long transmissions4 ,9 ,europe1 ! bir?place ( ! ?ree-phase sy/em1 x has fail$ to displace cont9u\s curr5t = transmission "w4 ,ab\t a score ( ^! cont9u\s-curr5t transmissions are already at "w !re4 ,if ! op9ion ( ,european eng9e]s z to ! l[] co/ ( ! cont9u\s-curr5t sy/em1 all o!r factors be+ equal1 is confirm$ by exp]i5ce1 ?is curr5t w yet f9d important applications to long transmissions 9 ! ,unit$ ,/ates4 ,sy/ems ( transmission ) cont9u\s-curr5t may op]ate at con/ant voltage & v>iable curr5t1 at con/ant curr5t & v>iable voltage1 or ) v>iations ( bo? volts & amp]es to correspond ) *anges ( load4 ,dynamos ( sev]al ?\s& kil[atts capacity ea* c readily be _h at voltages ( #ejj to #fjj1 b ! attempt to con/ruct dynamos to deliv] m ?an two or ?ree hundr$ kil[atts ea* at sev]al ?\s& volts has enc\nt]$ s]i\s sp>k+ at ! commutator4 ,?us f>1 dynamos t yield betwe5 #cjj & #djj kil[atts ea* h be5 made to give satisfactory results at pressures z high z #b1ejj volts4 ,ano!r "o ( ! ,swiss transmissions takes place ov] a di/ance ( ?irty-two miles at #ad1djj volts1 ! capacity be+ #b1afj kil[atts4 ,to give ?is voltage & capacity1 eight dynamos are connect$ 9 s]ies at ! g5]at+ /ation1 ea* dynamo hav+ an output ( #aej amp]es at #a1hjj volts1 or #baf kil[atts4 ,cont9u\s-curr5t motors are1 ( c\rse1 subject to ! same limitations z dynamos 9 ! matt] ( capacity at high voltage1 s t a s]ies ( motors mu/ be employ$ to receive ! high-pressure en]gy f ! l9e4 ,! numb] ( ^! motors may j equal1 or may be less or great] ?an ! numb] ( dynamos1 b ! total work+ voltage ( all ! motors 9 op]ation at "o "t mu/ equal ! total voltage ( ! dynamos 9 op]ation at t "t m9us ! volts ( drop 9 ! l9e4 ,ea* con/ant-curr5t motor may h any desir$ capacity up to ! practicable maximum1 b x mu/ be design$ = ! curr5t ( ! sy/em4 ,! voltage at ! t]m9als ( ea* motor v>ies ) its load1 be+ greate/ :5 ! motor is do+ ! mo/ "w4 ,con/ant spe$ is usually atta9$ at ea* motor by means ( a v>iable resi/ance connect$ across ! t]m9als ( ! magnet coils4 ,! am\nt ( ?is resi/ance is regulat$ by a c5trifugal gov]nor1 driv5 by ! motor %aft4 ,?is gov]nor also %ifts ! position ( ! bru%es on ! commutator to prev5t sp>k+ z ! curr5t fl[+ ?r\gh ! magnet coils is *ang$4 ,= a con/ant-curr5t transmission ! magnet & armature w9d+s ( bo? dynamos & motors are usually connect$ 9 s]ies ) ea* o!r & ! l9e s t ! same curr5t passes ?r\gh e elem5t ( ! circuit1 except t ea* motor may h "s curr5t %unt$ out ( its magnet coil = ! purpose ( spe$ regulation4 ,9 "s cases1 h[ev]1 ! magnet coils ( ! dynamos are connect$ 9 multiple ) ea* o!r & receive _! curr5t f a sep>ate dynamo design$ = ! purpose4 ,) ?is sep>ate excitation ( ! magnet coils1 ! dynamo armatures are /ill connect$ 9 s]ies ) ea* o!r & ! l9e4 ,! total voltage at ! g5]at+ /ation & on ! l9e ( a con/ant-curr5t sy/em v>ies ) ! rate at :i* en]gy is deliv]$1 & has its maximum value only at times ( full load4 ,to obta9 ?is v>iation ( voltage1 x is ! g5]al practice to *ange ! spe$ ( ! dynamos by means ( an automatic regulator :i* is actuat$ by ! l9e curr5t4 ,any increase ( ! l9e curr5t actuates ! regulator & r$uces ! spe$ ( ! dynamos1 :ile a decrease ( ! l9e curr5t raises ! dynamo spe$4 ,) a good regulator ! v>iations ( ! l9e curr5t are only slight4 ,"u ?is me?od ( regulation ! dynamos 9 op]ation h a sub/antially con/ant curr5t 9 bo? armature & magnet coils at all times1 s t !re is no reason to %ift ! position ( ! bru%es on ! commutator4 ,g5]at+ /ations ( con/ant curr5t transmission sy/ems are g5]ally driv5 by wat]-p[] & ! spe$ regulator op]ates to *ange ! am\nt ( wat] admitt$ to ea* :eel4 ,ea* turb9e :eel usually drives a pair ( dynamos1 b "o or any numb] ( dynamos might be driv5 by a s+le :eel4 ,! two dynamos driv5 by a s+le :eel are g5]ally connect$ 9 s]ies at all times1 & are cut 9 or out ( ! ma9 circuit toge!r4 ,:5 ! load on a con/ant-curr5t g5]at+ /ation is su* t ! voltage c be develop$ by less ?an all ! dynamos1 "o or m dynamos may be /opp$ & tak5 out ( ! circuit4 ,to d ?is ! dynamo or pair ( dynamos to be put out ( s]vice may be /opp$1 _! magnet coils hav+ fir/ be5 %ort-circuit$1 & !n a swit* across ! connections ( _! armatures to ! l9es clos$1 aft] :i* ! connections ( ! armatures to ! l9e are op5$4 ,by a rev]se process1 any dynamo or pair ( dynamos may be cut into ! op]at+ circuit4 ,at ! t]m9als ( ea* dynamo 9 ! s]ies1 :ile 9 op]ation1 ! voltage is simply t develop$ 9 its armature1 s t ! insulation betwe5 ! sev]al w9d+s is subject to only a correspond+ /ress4 ,! entire voltage ( ! l9e1 h[ev]1 t5ds to =ce a curr5t f ! coils ( ! dynamo at "o end ( ! s]ies into its frame1 !nce to any sub/ance on :i* t frame re/s1 & s on to ! frame & coils ( ! dynamo at ! o!r end ( ! s]ies4 ,to protect ! insulation ( ! dynamo coils f ! l9e voltage1 ?ick blocks ( porcela9 are plac$ b5ea? ! dynamo frames1 & ! armature %afts are connect$ to ^? ( ! turb9es by insulat+ c\pl+s4 ,besides ! swit*es1 already m5tion$1 a voltmet] & ammet] %\ld be provid$ = ea* dynamo & also = ! entire s]ies ( ma*9es4 ,?is completes ! swit*bo>d equipm5t1 :i* is1 !re=e1 v simple4 ,z ! l9e loss ( a con/ant-curr5t sy/em is ! same :atev] ! load t is be+ op]at$1 ?is loss may be a l>ge p]c5tage ( ! total output :5 ! load is light4 ,if1 = illu/ration1 five p] c5t ( ! maximum voltage ( ! /ation is requir$ to =ce ! con/ant curr5t ?r\gh ! l9e1 ! p]c5tage ( l9e loss w rise to t5 :5 ! /ation voltage is "o-half ! maximum1 & to tw5ty :5 ! /ation is deliv]+ only "o-qu>t] ( its full capacity4 ,9 view ( ?is prop]ty ( con/ant-curr5t work+1 ! l9e loss %\ld be made q small 9 its ratio to ! maximum load1 z mo/ /ations mu/ "w on p>tial loads mu* ( ! "t4 ,five p] c5t ( maximum /ation voltage is a fair g5]al figure = ! l9e loss 9 a con/ant-curr5t transmission1 b ! circum/ances ( a p>ticul> case may dictate a high] or a l[] p]c5tage4 ,on ! #cb-mile transmission1 above nam$1 ! loss 9 ! l9e is six p] c5t ( ! /ation output at full load4 ,if a transmission ) cont9u\s curr5t is to be c>ri$ out at con/ant pressure ! limitation z to ! capacity & voltage ( ea* dynamo is ab\t ! same z ) con/ant curr5t4 ,probably m en]gy is n[ transmitt$ by cont9u\s curr5t at con/ant pressure ?an by any o!r me?od1 ! great] "p be+ devot$ to electric railway "w at #ejj to #fjj volts4 ,dynamos = ab\t ^! voltages c readily be _h 9 capacities up to sev]al ?\s& kil[atts ea*1 b ! l5g? ( transmission t c be economically c>ri$ out at ?is pressure is comp>atively small4 ,= ea* kil[att deliv]$ to a l9e at #ejj volts & to be transmitt$ to a di/ance ( five miles at a t5 p] c5t loss 9 ! l9e1 ! weight ( copp] conductors mu/ be #cgb p\nds1 co/+ #ef4hj at #ae c5ts p] p\nd4 ,?is sum is twice to f\r times ! co/ ( good cont9u\s-curr5t dynamos p] kil[att ( capacity4 ,if ! di/ance ( transmission is t5 miles & ! voltage & l9e loss rema9 z be=e1 ! weight ( copp] conductor mu/ be increas$ to #a1dhh p\nds p] kil[att deliv]$ to ! l9e1 co/+ #bbg4bj4 ,exp]i5ce has %[n t 9 sizes ( n m ?an #djj kil[atts1 cont9u\s-curr5t dynamos may safely h a voltage ( #b1jjj ea*1 & any numb] ( su* dynamos may be op]at$ 9 multiple1 giv+ :atev] capacity is desir$4 ,at #b1jjj volts & a loss ( #aj p] c5t 9 ! l9e ! weight ( copp] conductors p] kil[att w\ld be #ic p\nds1 co/+ #ac4ie1 = ea* kil[att deliv]$ to ! l9e on a #aj-mile transmission4 ,) #b1jjj volts on a #bj-mile transmission ! weight ( conductors p] kil[att w\ld be ! same z _! weight on a #e-mile transmission at #ejj volts1 ! p]c5tage ( loss be+ equal 9 ! two cases4 ,l>ge cont9u\s-curr5t motors (1 say1 #ej kil[atts or m c be _h = a pressure ( #b1jjj volts1 s t any numb] ( su* motors might be op]at$ f a #b1jjj-volt1 con/ant-pressure l9e entirely indep5d5t ( ea* o!r4 ,f ^! figures x is evid5t t a transmission ( #aj miles may be c>ri$ out ) cont9u\s-curr5t at con/ant pressure f a s+le dynamo ) good effici5cy & a mod]ate inve/m5t 9 conductors4 ,:5 ! di/ance is su* t mu* m ?an #b1jjj volts are requir$ = ! con/ant-pressure transmission1 ) cont9u\s curr5t1 resort mu/ be _h to ! connection ( dynamos & motors 9 s]ies4 ,any numb] ( dynamos may be s connect$ z 9 ! case ( con/ant-curr5t "w4 ,! comb9$ voltages ( ! s]ies ( motors connect$ to ! con/ant-pressure transmission l9e mu/ equal ! voltage ( t l9e1 s t ! numb] ( motors 9 any "o s]ies mu/ be con/ant4 ,if ! voltage ( transmission is s high t m ?an two or ?ree motors mu/ be connect$ 9 ea* s]ies1 !re comes ! objection t motors mu/ be op]at$ at light loads dur+ mu* ( ! "t4 ,moreov]1 ea* s]ies ( motors mu/ be me*anically connect$ to ! same "w1 z t ( driv+ a s+le dynamo or o!r ma*9e1 because if ! loads on ! motors ( a s]ies v>y diff]5tly1 ^! motors w n op]ate at con/ant spe$4 ,cont9u\s-curr5t transmission at con/ant pressure ) motors 9 s]ies ?us lacks ! flexibility ( transmission at con/ant curr5t :]e any motor may be />t$ & /opp$ )\t reg>d to ! o!rs 9 ! s]ies1 ! l9e voltage be+ automatically regulat$ at ! g5]at+ /ation accord+ to ! numb] ( motors 9 use at any "t & to ! "w !y are do+4 ,9 ! effici5cy ( its dynamos1 motors & l9e1 a con/ant-pressure sy/em ( transmission is sub/antially equal to "o ) con/ant curr5t at full load4 ,at p>tial loads ! con/ant-pressure l9e has ! advantage because ! loss ( en]gy 9 x v>ies ) ! squ>e ( ! load4 ,?us at con/ant pressure ! l9e loss 9 en]gy p] h\r at half-load is only "o-f\r? z great z ! loss at full load4 ,on ! o!r h&1 ! en]gy loss 9 ! con/ant-curr5t l9e is ! same at all /ages ( load4 ,because ( ^! facts x is good practice to all[1 say1 a t5-p]-c5t loss 9 a con/ant-pressure l9e & only five p] c5t 9 a con/ant-curr5t l9e at full load4 ,9 a g5]at+ /ation at #b1jjj volts or m con/ant pressure1 x is desirable to h ! magnet coils ( ! ma9 dynamos connect$ 9 multiple & sep>ately excit$ by a small dynamo at con/ant pressure4 ,?is plan is especially desirable :5 ! armatures ( sev]al dynamos are connect$ 9 s]ies to obta9 ! l9e voltage4 ,sep>ately excit$ magnet coils make x easi] to control ! op]ation ( ! sev]al dynamos1 coils ( l[-voltage are *eap] to make ?an coils ( high voltage1 & ! l[ voltage w9d+s are less liable to burn out4 ,if a s]ies ( con/ant-pressure motors is 9 use at "o po9t1 x may be *eap] & saf] to excite its magnet coils f a special dynamo ?an f ! l9e4 ,9 a transmission c>ri$ out ) s]ies-w\nd dynamos & motors1 ! spe$ ( ! motors may be con/ant at all loads )\t any special regulat+ me*anism4 ,to atta9 ?is result x is necess>y t all ! motors be c\pl$ s z to =m a s+le unit me*anically & t ! dynamos be driv5 at con/ant spe$4 ,a transmission sy/em ( ?is sort may include a s+le dynamo & a s+le motor1 or two or m dynamos1 & two or m motors may be us$ 9 s]ies4 ,:5 ! dynamos ( su* a sy/em are driv5 at con/ant spe$ & a v>iable load is appli$ to ! s+le motor1 or to ! me*anically connect$ motors1 bo? ! voltage ( ! sy/em & ! amp]es fl[+ 9 all its p>ts *ange toge!r s t practically con/ant spe$ is ma9ta9$ at ! motors1 provid$ t ! design ( bo? ! dynamos & motors is suitable = ! purpose4 ,) ! maximum load on ! motors ! volts & amp]es ( ! sy/em h _! greate/ values1 & ^! values bo? decl9e ) small] loads4 ,! *ief disadvantage ( ?is sy/em lies 9 ! fact t :]e m ?an "o motor is employ$ all ! motors mu/ be me*anically jo9$ toge!r s z to "w on ! same load4 ,comp>$ ) ! con/ant-curr5t sy/em1 ?is comb9ation ( s]ies dynamos ) me*anically connect$ s]ies motors has ! di/9ct advantage t nei!r ! dynamos nor motors require any sort ( regulators 9 ord] to ma9ta9 con/ant motor spe$4 ,x is only necess>y t ! dynamos be driv5 at con/ant spe$ & t bo? ! dynamos & motors be design$ = ! transmission4 ,9 comp>ison ) a con/ant-pressure sy/em1 ! "o "u consid]ation has ! advantage t nei!r its dynamos nor motors require magnet coils ) a high voltage at _! t]m9als & compos$ ( f9e wire or sep>ate excitation by a special dynamo4 ,^! features ( ! sy/em ) s]ies dynamos & motors1 ! latt] be+ jo9$ z a me*anical unit1 make x *eap] to in/all & easi] to op]ate ?an ei!r ( ! o!r two4 ,?is sy/em is especially adapt$ = ! deliv]y ( me*anical p[] 9 r l>ge units4 ,! voltage available may be any?+ desir$1 b is subject to ! practical limitations t all ! motors mu/ deliv] _! p[] z a me*anical unit1 s t unless ! p[] is q l>ge ! numb] ( motors 9 ! s]ies &1 !re=e1 ! voltage is limit$4 ,an int]e/+ illu/ration ( ! sy/em ( transmission j describ$ exi/s betwe5 a po9t on ! ,riv] ,suze1 ne> ,bi5ne1 ,switz]l&1 & ! ,bib]e/ pap] mills4 ,at ! riv] a #djj horse-p[] turb9e wat]-:eel drives a pair ( s]ies-w\nd dynamos1 ea* rat$ at #acj kil[atts & #c1cjj volts4 ,^! dynamos are connect$ 9 s]ies1 giv+ a total capacity ( #bfj kil[atts & a pressure ( #f1fjj volts4 ,at ! ,bib]e/ mills are locat$ two s]ies-w\nd motors1 me*anically c\pl$ & connect$ 9 s]ies ) ea* o!r & ) ! two-wire transmission l9e1 :i* ext5ds f ! two dynamos at ! ,riv] ,suze4 ,ea* ( ^! motors has a capacity & voltage equal to t ( ei!r ( ! dynamos previ\sly m5tion$4 ,! c\pl$ motors op]ate at ! con/ant spe$ ( #bjj revolutions p] m9ute at all loads & deliv] ov] #cjj horse-p[] :5 do+ maximum "w4 ,betwe5 ! g5]at+ plant at ! riv] & ! ,bib]e/ mills ! di/ance is ab\t #ai miles1 & ! two l9e wires are ea* ( copp]1 #bge mils1 or a little m ?an "o-f\r? in* 9 diamet]4 ,! dynamos & motors ( ?is sy/em are m\nt$ on ?ick porcela9 blocks 9 ord] to protect ! insulation ( _! w9d+s f ! /ra9 ( ! full-l9e voltage4 ,ei!r ( ! ?ree sy/ems ( transmission by cont9u\s-curr5t t h be5 consid]$ requires a small] total capacity ( electrical app>atus = a giv5 rate ( me*anical p[] deliv]y ?an any sy/em us+ alt]nat+ curr5t except t :]e bo? ! dynamos & motors op]ate at l9e voltage4 ,,*apt] ,v4 ,,! ,,physical ,,limits ,,( ,,electric-,,p[] ,,transmission4 ,electrical en]gy may be transmitt$ ar\nd ! _w if ! l9e voltage is unlimit$4 ,?is foll[s f ! law t a giv5 p[] may be transmitt$ to any di/ance ) con/ant effici5cy & a fix$ weight ( conductors1 provid$ ! voltage is increas$ directly ) ! di/ance4 ,! physical limits ( electric-p[] transmission are ?us fix$ by ! practicable voltage t may be employ$4 ,! effects ( ! voltage ( transmission mu/ be met 9 ! app>atus at g5]at+ & receiv+ /ations on ! "o h&1 & along ! l9e on ! o!r4 ,9 bo? situations exp]i5ce is ! ma9 guide1 & !ory has little t is reliable to (f] z to ! limit beyond :i* ! voltage w prove unworkable4 ,electric g5]ators are ! po9ts 9 a transmission sy/em :]e ! limit ( practical voltage is fir/ rea*$4 ,9 almo/ all high-voltage transmissions ( ! pres5t day 9 ! ,unit$ ,/ates alt]nat+ g5]ators are employ$4 ,v few if any cont9u\s-curr5t dynamos ) capacities 9 ! hundr$s ( kil[atts & voltages above #d1jjj h be5 built 9 ,europe1 & probably none 9 ! ,unit$ ,/ates4 ,:]e a transmission at high voltage is to be accompli%$ ) cont9u\s curr5t1 two or m dynamos are usually jo9$ 9 s]ies at ! g5]at+ /ation1 & a simil> arrangem5t ) motors is made at ! receiv+ /ation1 s t ! desir$ voltage is available at ! l9e ?\gh n pres5t at any "o ma*9e4 ,alt]nat+ dynamos t deliv] curr5t at ab\t #f1jjj volts h be5 9 regul> use = "s ye>s1 9 capacities ( hundr$s ( kil[atts ea*1 & may readily be _h ( sev]al ?\s& kil[atts capacity4 ,b ev5 #f1jjj volts is n an economical pressure = transmissions ov] fifte5 to fifty miles1 su* z are n[ q common2 consequ5tly 9 su* transmissions x has be5 ! rule to employ alt]nators t op]ate at less ?an #c1jjj volts1 & to raise ?is voltage to ! desir$ l9e pressure by /ep-up trans=m]s at ! g5]at+ /ation4 ,m rec5tly1 h[ev]1 ! voltage ( alt]nat+ g5]ators has be5 pu%$ z high z #ac1jjj 9 ! revolv+-magnet type :]e all ! armature w9d+s are /ation>y4 ,?is voltage makes x practicable to disp5se ) ! use ( /ep-up trans=m]s = transmissions up to or ev5 beyond #cj miles 9 "s cases4 ,?is voltage ( #ac1jjj 9 ! armature coils is atta9$ only by con/ructions involv+ "s difficulty because ( ! relatively l>ge am\nt ( room necess>y = ! insulat+ mat]ials on coils t develop ?is pressure4 ,! t5d5cy ( ?is con/ruction is to give alt]nators unusually l>ge dim5sions p] giv5 capacity4 ,x seems probable1 moreov]1 t ! pressures develop$ 9 ! armature coils ( alt]nat+ g5]ators mu/ rea* _! high] limits at a po9t mu* bel[ ! #ej1jjj & #fj1jjj volts 9 actual use on pres5t transmission l9es4 ,9 ! longe/ transmissions ) alt]nat+ curr5t !re is1 !re=e1 little prospect t /ep-up trans=m]s at ! g5]at+ /ations & /ep-d[n trans=m]s at receiv+ /ations c be disp5s$ )4 ,! highe/ voltage t may be receiv$ or deliv]$ at ^! /ations is simply ! highe/ t x is practicable to develop by trans=m]s & to transmit by ! l9e4 ,a v high degree ( insulation is mu* m easy to atta9 9 trans=m]s ?an 9 g5]ator armatures1 because ! space t c be readily made available = insulat+ mat]ials is f> great] 9 ! trans=m]s1 & fur!r because _! con/ruction p]mits ! complete imm]sion ( _! coils 9 petroleum4 ,?is oil (f]s a mu* great] resi/ance ?an air to ! passage ( electric sp>ks1 :i* t5d to set up arcs betwe5 coils at v high voltages & ?us de/roy ! insulation4 ,dang] to insulation f ! effect kn[n z creep+ betwe5 coils at widely diff]5t pressures is l>gely avoid$ by imm]sion ( ! coils 9 oil4 ,= sev]al ye>s gr\ps ( trans=m]s h be5 work$ regul>ly at #dj1jjj to #fj1jjj volts1 & 9 no in/ance is !re any indication t ! upp] limit ( practicable voltage has be5 rea*$4 ,on ! contr>y1 trans=m]s h repeat$ly be5 work$ exp]im5tally up to & above #ajj1jjj volts4 ,f all ^! facts1 & o!rs ( simil> import1 x is fair to conclude t ! physical limit to ! voltages t x is practicable to obta9 ) trans=m]s is mu* above ! #ej1jjj or #fj1jjj volts n[ 9 practical use on transmission sy/ems4 ,s f> z pres5t practice is conc]n$1 ! limit to ! use ( high voltages mu/ be s\ght beyond ! trans=m]s & outside ( g5]at+ & receiv+ /ations4 ,z n[ con/ruct$1 ! l9e is t "p ( ! transmission sy/em :]e a physical limit to ! use ( high] voltages w fir/ be rea*$4 ,! factors t t5d mo/ directly to ?is limit are two3 tempor>y arc+ betwe5 ! sev]al wires on a pole1 & ! less impos+ b con/ant passage ( en]gy f "o wire to ano!r4 ,on l9es ( v high voltage arc+ is occasionally set up by "o ( sev]al causes4 ,at a po9t :]e "o or m ( ! insulators on :i* ! wires are m\nt$ become brok5 or defective1 ! curr5t is apt to fl[ f "o wire to ano!r along a wet cross-arm1 until ! wood gr[s c>boniz$ & an arc is =m$ t ends by burn+ up ! cross-arm or ev5 ! pole4 ,:]e l9es are expos$ to heavy sea fog1 ! salt is 9 "s cases deposit$ on ! insulators & cross-arms to an ext5t t />ts an arc betwe5 ! wires1 & ends (t5 9 ! de/ruction ( ! cross-arm4 ,9 "s in/ances ! glass & porcela9 insulators support+ wires us$ ) high voltages are punctur$ by sp>ks t pass "r ?r\gh ! mat]ial ( ! insulator to ! p9 on :i* x is m\nt$1 ?us burn+ ! p9 & ultimately ! cross-arm4 ,?is tr\ble is easily met1 h[ev]1 by ! adoption ( a bett] grade ( porcela9 or ( an insulator ) a great] ?ickness ( glass or porcela9 betwe5 ! wires & ! support+ p94 ,arcs betwe5 l9es at high voltages usually />t by sp>ks t jump f ! l[] edges ( insulators1 :5 !y are wet or cov]$ ) salt deposit1 to ! cross-arm4 ,z ! l[] edges ( insulators are only a few in*es f _! cross-arms1 ! sp>ks f9d a pa? ( comp>atively l[ resi/ance by pass+ f insulator to cross-arm & !nce to ! o!r insulator & wire4 ,! wood ( a wet cross-arm is a f> bett] conductor ?an ! air4 ,:]e wires are sev]al feet or m ap>t1 sp>ks probably nev] jump directly ?r\gh ! air f "o to ! o!r4 ,l>ge birds fly+ close to su* wires1 h[ev]1 h 9 "s in/ances />t$ mom5t>y arcs betwe5 !m4 ,! treatm5t ( cross-arms ) oil or p>aff9e r$uces ! numb] ( arcs t occur on a l9e ( high voltage1 b does n d away ) !m4 ,z ! voltages ( long transmissions h gone up1 ! di/ance ?r\gh ! air betwe5 wires & ! di/ances betwe5 ! l[] wet edges ( insulators & ! cross-arms h be5 mu* increas$4 ,mo/ ( ! e>li] transmission l9es = high voltages 7 erect$ on insulators spac$ f "o to two feet ap>t4 ,9 contra/ ) ?is practice1 ! ?ree wires ( ! transmission l9e 9 op]ation at #ej1jjj volts betwe5 ,caon ,f]ry & ,butte are arrang$ at ! corn]s ( a triangle sev5ty-eight in*es ap>t1 "o wire at ! top ( ea* pole & ! o!r two at opposite ends ( ! cross-arm4 ,a voltage t w\ld j />t an arc along a wet cross-arm betwe5 wires eighte5 in*es ap>t w\ld be q p[]less to d s ov] sev5ty-eight in*es ( cross-arm1 ! l[] wet edges ( insulators be+ equidi/ant f cross-arms 9 ! two cases4 ,to rea* ! cross-arm1 ! electric curr5t passes d[n ov] ! wet or dirty outside surface ( ! insulator to its l[] edge4 ,9 ! old] types ( insulators ! l[] wet edge (t5 came )9 two in*es ( ! cross-arm4 ,= ! #ej1jjj-volt l9e j m5tion$ ! insulators 7see illus47 are m\nt$ ) _! l[] wet edges ab\t eight in*es above ! cross-arms4 ,at its l[] edge ea* insulator has a diamet] ( n9e in*es1 & a small glass sleeve ext5ds sev]al in*es bel[ ?is edge & close to ! wood5 p91 to prev5t sp>k+ f ! l[] wet edge ( ! insulator to ! p94 ,^! increas$ di/ances betwe5 wires 9 a direct l9e ?r\gh ! air1 & also ! great] di/ances betwe5 ! l[] wet edges ( insulators & _! p9s & cross-arms1 are prov+ fairly effective to prev5t s]i\s arc+ "u good climatic conditions1 = ! maximum pressures ( #ej1jjj to #fj1jjj volts n[ 9 use4 ,if ^! voltages are to be greatly exce$$ x is practically c]ta9 t ! di/ance betwe5 wires1 & f ! l[] wet edges ( insulators to ! wood ( poles or cross-arms1 mu/ be /ill fur!r increas$ to avoid de/ructive arc+4 ,! ne>e/ approa* to an absolute physical limit ( voltage ) pres5t l9e con/ruction is met 9 ! con/ant curr5t ( en]gy ?r\gh ! air f wire to wire ( a circuit4 ,a pap] 9 vol4 ,,xv41 ,transactions ,am]ican ,in/itute ,electrical ,eng9e]s1 gives ! te/s made at ,telluride1 ,col41 to det]m9e ! rates at :i* en]gy is lo/ by pass+ ?r\gh ! air f "o wire to ano!r ( ! same circuit4 ,! te/s at ,telluride 7 made ) two-wire circuits /rung on a pole l9e #aa1gbj feet 9 l5g?1 at fir/ ) iron wires ( #j4afe in* diamet] & !n ) copp] wires ( #j4afb in* diamet]4 ,measurem5ts 7 made ( ! en]gy escap+ f wire to wire at diff]5t voltages on ! l9e1 & also ) ! two wires at v>i\s di/ances ap>t4 ,x 0 f\nd t ! loss ( en]gy ov] ! surfaces ( insulators 0 v slight1 & t ! loss incid5t to ! passage ( en]gy directly ?r\gh ! air is ! ma9 "o to be consid]$4 ,?is leakage ?r\gh ! air v>ies ) ! l5g? ( ! l9e1 z might be expect$4 ,te/s 7 made ) pairs ( wires runn+ ! entire l5g? ( ! pole l9e & at di/ances ( #ae1 #bb1 #ce1 & #eb in*es ap>t respectively4 ,losses ) wires #bb or #ce in*es ap>t 7 int]m$iate to ! losses :5 wires 7 #ae & #eb in*es ap>t respectively4 ,results giv5 9 ! orig9al pap] = ! pair ( wires t 7 #ae in*es ap>t & = ! pair t 7 #eb in*es ap>t are "h r$uc$ to approximate watts p] mile ( two-wire l9e4 ,at #dj1jjj volts ! loss betwe5 ! two wires t 7 #ae in*es ap>t 0 ab\t #aej watts p] mile1 & betwe5 ! two wires t 7 #eb in*es ap>t ! loss 0 #hd watts p] mile4 ,! two wires #ae in*es ap>t %[$ a leakage ( approximately #dac watts p] mile :5 ! voltage 0 up to #dd1jjj1 b ! wires #eb in*es ap>t 7 subject to a leakage ( only #id watts p] mile at ! same voltage4 ,at #dg1cjj volts1 ! highe/ pressure record$ = ! two wires #ae in*es ap>t1 ! leakage betwe5 !m 0 ab\t #a1bae watts p] mile1 :ile an equal voltage on ! two wires #eb in*es ap>t caus$ a leakage ( only #abb watts p] mile1 or "o-t5? ( t betwe5 ! wires t 7 #ae in*es ap>t4 ,:5 ab\t #ej1jjj volts 7 rea*$ on ! two wires #eb in*es ap>t1 ! leakage betwe5 !m am\nt$ to #adj watts p] mile2 b beyond ?is voltage ! loss w5t up rapidly1 & 0 #bbe watts p] mile at ab\t #ed1fjj volts4 ,= high] pressures ! loss betwe5 ^! two wires /ill m rapidly increas$1 & am\nt$ to #a1cfh watts p] mile ) ab\t #ei1cjj volts1 ! highe/ pressure record$4 ,) a loss ( ab\t #a1bae watts p] mile betwe5 ! two wires #eb in*es ap>t1 ! voltage on !m 0 #eh1hjj1 9 contra/ ) ! #dg1cjj volts produc+ ! same leakage on ! two wires #ae in*es ap>t4 ,evid5tly1 h[ev]1 at ev5 #eb in*es betwe5 l9e wires ! limit ( high voltage is n f> away4 ,:5 ! voltage on ! #eb-;in* l9e 0 rais$ f #ed1fjj to #ei1cjj1 ! leakage loss betwe5 ! two wires increas$ ab\t #a1adc watts p] mile4 ,if ! leakage increases at lea/ 9 l proportion1 z seems probable1 = /ill high] pressures1 ! loss betwe5 ! two wires w\ld am\nt to #f1cba watts p] mile ) #hj1jjj volts on ! l9e4 ,on a l9e #bjj miles long ?is loss by leakage betwe5 ! two wires w\ld am\nt to #a1bfd1bjj watts4 ,any su* leakage z ?is obvi\sly sets an absolute1 physical limit to ! voltage1 & consequ5tly ! l5g? ( transmission4 ,=tunately = ! future deliv]y ( en]gy at great di/ances f its s\rce1 ! means to avoid ! limit j discuss$ are n difficult4 ,o!r exp]im5ts h %[n t ) a giv5 voltage & di/ance betwe5 conductors ! loss ( en]gy f wire to wire decreases rapidly z _! diamet]s increase4 ,! electrical resi/ance ( air1 l t ( any o!r sub/ance1 increases ) ! l5g? ( ! circuit ?r\gh x4 ,! leakage describ$ is a fl[ ( electrical en]gy ?r\gh ! air f "o wire to ano!r ( ! same circuit4 ,to r$uce ?is leakage x is simply necess>y to give ! pa? f wire to wire ?r\gh ! air great] electrical resi/ance by increas+ its l5g?1 t is1 by plac+ ! wires at great] di/ances ap>t4 ,! fact demon/rat$ at ,telluride1 t ) #dg1cjj volts on ea* l9e ! leakage p] mile betwe5 ! two wires #ae in*es ap>t 0 t5 times z great z ! leakage betwe5 ! two wires #eb in*es ap>t1 is full ( mean+4 ,evid5tly1 leakage ?r\gh ! air may be r$uc$ to any desir$ ext5t by suitable increase ( di/ance betwe5 ! wires ( ! same circuit4 ,b to c>ry ?is increase ( di/ance betwe5 wires v f> involves radical *anges 9 l9e con/ruction4 ,?us f> x has be5 ! uni=m practice to c>ry ! two or ?ree wires ( a transmission circuit on a s+le l9e ( poles1 & 9 _m cases sev]al su* circuits are m\nt$ on ! same pole l9e4 ,= ! #fe mile transmission into ,butte1 ,mont41 only ! ?ree wires ( a s+le circuit are m\nt$ on "o pole l9e1 & ?is repres5ts ! be/ pres5t practice4 ,! cross-arms on ?is l9e are ea* #h feet long1 & "o is atta*$ to ea* pole4 ,! poles are n less ?an #ce feet long & h #h-;in* tops4 ,"o wire is m\nt$ at ! top ( ea* pole1 & ! o!r two wires ne> ! ends ( ! cross-arm1 s t ! ?ree wires are equidi/ant & #gh in*es ap>t4 ,by ! use ( /ill heavi] poles ! l5g? ( cross-arms may be increas$ to #ab or #ad feet1 = :i* _! section %\ld be n less ?an #d by #f in*es4 ,plac+ "o wire at ! pole top1 ! #ab-;foot cross-arm w\ld p]mit ! ?ree wires ( a circuit to be spac$ ab\t #aj4e feet ap>t4 ,! co/ ( extra l>ge poles goes up rapidly & !re are alt]native con/ructions t seem bett] suit$ to ! case4 ,moreov]1 a few t5s ( ?\s&s ( volts above pres5t practice w\ld br+ u aga9 to a po9t :]e ev5 #aj4e feet betwe5 wires w\ld n prev5t a prohibitive leakage4 ,two poles might be set #bj feet ap>t1 ) a cross-piece betwe5 !m1 ext5d+ out #e feet beyond ea* pole & hav+ a total l5g? ( #cj feet4 ,?is w\ld p]mit ?ree wires to be m\nt$ along ! cross-piece at po9ts ab\t #ad feet ap>t4 ,if ! pres5t transmission pressures ( #ej1jjj to #fj1jjj volts are to be greatly exce$$1 ! l9e /ructure may involve ! use ( a sep>ate pole = ea* wire ( a circuit1 ea* wire to be m\nt$ at ! top ( its pole4 ,?is con/ruction calls = ?ree l9es ( poles to c>ry ! ?ree wires ( a ?ree-phase transmission4 ,ea* ( ^! poles may be ( only mod]ate dim5sions1 say #cj feet long ) #f- or #g-;in* top4 ,! co/ ( ?ree ( ^! poles w exce$ by only a mod]ate p]c5tage t ( a #ce- or #dj-;foot pole ) an #h- to #aj-;in* top1 su* z w\ld be necess>y ) #ab-;foot cross-arms4 ,! di/ance betwe5 ^! poles at "r angles to ! l9e may be any?+ desir$1 s t leakage f wire to wire ?r\gh ! air w be r$uc$ to a trifl+ matt] at any voltage4 ,extra long p9s & insulators at ! pole tops w easily give a di/ance ( two feet or m betwe5 ! l[] wet edge ( ea* insulator & ! wood ( p9 or pole4 ,su* l9e con/ruction w\ld probably safely c>ry two or ?ree times ! maximum voltage ( pres5t practice1 & might =ce ! physical limit ( electrical transmission back to ! highe/ pressure at :i* trans=m]s c\ld be op]at$4 ,) n m ?an #fj1jjj volts on ! l9e ! size ( conductors is great en\gh 9 _m cases to keep ! loss ( en]gy betwe5 !m )9 mod]ate limits :5 !y are six feet ap>t1 b ) a l>ge increase ( voltage ! size ( conductors mu/ g up or ! di/ances betwe5 !m mu/ increase4 ,,*apt] ,,vi4 ,,developm5t ,,( ,,wat]-,,p[] ,,= ,,electric ,,/ations4 ,electrical transmission has r$uc$ ! co/ ( wat]-p[] developm5t4 ,)\t transmission ! p[] mu/ be develop$ at a numb] ( diff]5t po9ts 9 ord] t !re may be room en\gh = ! build+s 9 :i* x is to be utiliz$4 ,?is condition necessitates relatively long canals to conduct ! wat] to ! sev]al po9ts :]e p[] is to be develop$1 & also a relatively l>ge area ( l& ) canal & riv] frontage4 ,) electrical transmission ! p[]1 h[ev] great1 may well be develop$ at a s+le spot & on a v limit$ area ( l&4 ,! canal 9 ?is case may be m]ely a %ort passageway f "o end ( a dam to a ne>-by p[]-h\se1 or may disappe> entirely :5 ! p[]-h\se itself =ms ! dam1 z is sometimes ! case4 ,^! diff]5ces betwe5 ! di/ribution ( wat] = p[] purposes & ! developm5t by wat] ( electrical en]gy = transmission may be illu/rat$ by _m examples4 ,a typical case ( ! di/ribution ( wat] to ! po9ts :]e p[] is want$ may be se5 9 ! hydraulic developm5t ( ! ,amoskeag ,manufactur+ ,company at ,man*e/]1 ,n4 ,h4 ,?is developm5t includes a dam across ! ,m]rimac ,riv]1 & two p>allel canals t foll[ "o ( its banks = ab\t #c1djj feet d[n /ream4 ,by means ( a /one dam & a natural fall a little beyond its toe a wat] head ( ab\t =ty-eight feet is obta9$ at ! upp] end ( ! high-level canal4 ,bel[ ?is po9t !re is little drop 9 ! b$ ( ! riv] ?r\gh t "p ( its c\rse t is p>allel$ by ! two canals4 ,all ( ! p[] might be ?us develop$ )9 a few rods ( "o end ( ! dam1 if means 7 provid$ = its di/ribution to ! po9ts :]e x mu/ be us$4 ,ye>s ago1 :5 ?is wat]-p[] 0 develop$1 ! electrical transmission or di/ribution ( en]gy 0 unhe>d (1 & di/ribution ( ! wat] itself _h !re=e to be adopt$4 ,= ?is purpose ! two canals already m5tion$ 7 con/ruct$ along ! high bank ( ! riv] at two diff]5t levels4 ,illu/ration3 ,,fig4 #d4--;,hydraulic ,developm5t on ! ,m]rimac ,riv]4 ,! high-level canal1 s call$1 0 design$ to take wat] directly f ! bas9 or =ebay a little bel[ "o end ( ! dam1 s t betwe5 ?is canal & ! riv] !re is a full wat] head ( ab\t =ty-eight feet4 ,ov] ne>ly its entire c\rse ! ne>] side ( ?is high-level canal runs betwe5 #dej & #gej feet f ! edge ( ! riv] wall1 & ?us includes betwe5 x & ! riv] a l>ge area on :i* factories to be driv5 by wat]-:eels may be locat$4 ,x 0 ?\ght1 h[ev]1 t ?is /rip ( l& betwe5 ! high-level canal & ! riv] 0 too wide = a s+le r[ ( mill sites1 & ! l[] level canal 0 !re=e con/ruct$ p>allel ) t on ! high] level1 b ) ab\t tw5ty-"o feet less elevation4 ,betwe5 ^! two canals a /rip ( l& ab\t #bej feet wide 0 left = ! location ( mills4 ,by ?is arrangem5t ( canals x is possible to supply :eels locat$ betwe5 ! high & ! l[ levels ) wat] "u a head ( ab\t tw5ty-"o feet1 & to supply :eels betwe5 ! l[] canal & ! riv] ) wat] "u a head ( ab\t tw5ty-n9e feet4 ,! entire area ( l& betwe5 ! high canal & ! riv] is ?us made readily available = factory build+s4 ,wat] = ! l[] canal is drawn ma9ly f ! high canal ?r\gh ! :eels 9 build+s t are locat$ betwe5 ! two canals4 ,x is desirable 9 a case ( ?is sort to h z mu* wat] fl[ ?r\gh ! :eels betwe5 ! high & l[ canal z fl[s ?r\gh ! :eels betwe5 ! l[ canal & ! riv]1 b ?is is n always possible4 ,a gate is !re=e provid$ at ! =ebay :]e ! two canals />t1 by :i* wat] may pass f ! =ebay directly into ! l[ canal :5 necess>y1 b ! head ( tw5ty-"o feet betwe5 ! =ebay & ! l[ canal is lo/ z to ?is wat]4 ,betwe5 ! high & l[ canal1 & betwe5 ! l[ canal & ! riv] tw5ty-?ree turb9e :eels or pairs ( :eels h be5 connect$1 & ^! :eels h a comb9$ rat+ ( #i1ejj horse-p[]4 ,to c>ry out ?is hydraulic developm5t x ?us appe>s t ab\t #a4c miles ( canal h be5 con/ruct$2 "o-half ?is l5g? ( riv]-front has be5 requir$1 & ab\t "o-six? squ>e mile ( t]ritory has be5 occupi$4 ,contra/ ) ?is result :at might h be5 done if electrical transmission ( p[] _h be5 available at ! "t :5 ?is wat]-p[] 0 develop$4 ,all b a few rods 9 l5g? ( ! exi/+ #a4c miles ( canal might h be5 omitt$1 & an electric g5]at+ /ation ) :eels to take ! entire fl[ ( ! riv] might h be5 locat$ n f> f "o end ( ! dam4 ,factories utiliz+ ! electric p[] ?us develop$ might h be5 locat$ at any conv5i5t po9ts along ! riv]-front or else:]e1 & no space w\ld h be5 made unavailable because ( ! necessity ( head- & tail-wat] connections to scatt]$ sets ( :eels4 ,comp>e ) ! =ego+ hydraulic developm5t t at ,caon ,f]ry on ! ,miss\ri ,riv]1 9 ,montana1 :]e #aj1jjj horse-p[] is develop$ "u a wat]-head ( #cb feet4 ,at ,caon ,f]ry ! p[]-h\se is #bbe feet by #ej feet at ! floor level inside1 conta9s turb9e :eels direct-connect$ to t5 ma9 g5]ators ( #g1ejj kil[atts1 or #aj1jjj horse-p[] comb9$ capacity1 & is built on ! riv] bank close to "o end ( ! #ejj-;foot dam4 ,! canal :i* runs along ! l& side ( ! p[]-h\se1 & takes wat] at ! up-/ream side ( ! abutm5t1 is ab\t twice ! l5g? ( ! p[]-h\se itself4 ,! sav+ 9 ! co/ ( canal con/ruction alone1 to say no?+ ( ! sav+ z to ! requir$ area ( l&1 is evid5tly a l>ge item 9 favor ( ! electrical developm5t & transmission4 ,9 its small area & %ort canal ! ,caon ,f]ry plant is n an exception1 b is r typical ( a l>ge class ( electric wat]-p[] plants t op]ate "u mod]ate heads4 ,a l case may be se5 9 ! plant at ,r$ ,bridge1 on ! ,*icopee ,riv]1 9 ,massa*usetts1 :]e a canal #cdj feet long1 toge!r ) p5/ocks #ajj feet long1 convey wat] f "o end ( ! dam & deliv] x to :eels 9 ! electric /ation ) a head ( #di feet4 ,?is /ation conta9s electric g5]ators ) a comb9$ capacity ( #d1hjj kil[atts or #f1djj horse-p[]1 & its floor area is #ada by #eg feet4 ,illu/ration3 ,,fig4 #e4--;,canal at ,r$ ,bridge on ,*icopee ,riv]4 ,s1 aga91 at ,great ,falls1 on ! ,presumpscot ,riv]1 9 ,nor? ,gorham1 ,me4 7see cut71 ! electric /ation sets ab\t #dj feet 9 front ( ! =ebay wall1 :i* adjo9s "o abutm5t ( ! dam1 & !re is no canal :atev]1 z %ort p5/ocks br+ wat] to ! :eels ) a head ( #ce feet4 ,9 gr\nd area ?is /ation is #fg4e by #ee feet1 & its capacity 9 ma9 g5]ators is #b1jjj kil[atts or #b1gjj horse-p[]4 ,a /rik+ illu/ration ( ! ext5t to :i* electrical transmission r$uces ! co/ ( wat]-p[] developm5t may be se5 at ,gregg's ,falls on ! ,piscataquog ,riv]1 9 ,new ,hamp%ire1 :]e an electric /ation ( #a1bjj kil[atts capacity has be5 built close to "o end ( ! dam1 & receives wat] = its :eels "u a head ( #ea feet ?r\gh a %ort p5/ock1 #aj feet 9 diamet]1 t pi]ces "o ( ! abutm5ts4 ,illu/ration3 ,,fig4 #f4 ,p]haps ! greate/ electric wat]-p[] /ation any:]e t re/s close to ! dam t provides ! head = its :eels is t at ,spi] ,falls 7see cut71 on ! upp] ,hudson4 ,"o end ( ?is /ation is =m$ by ! high wall section ( ! dam1 & f ?is wall ! l5g? ( ! /ation d[n-/ream is #cib feet1 :ile its wid? is #gj feet #aj in*es1 bo? dim5sions be+ tak5 inside4 ,! canal or =ebay 9 ?is case1 l t at ,caon ,f]ry1 lies on ! bank side ( ! p[]-/ation1 & is ab\t equal to x 9 l5g?4 ,f ?is canal t5 %ort p5/ocks1 ea* #ab feet 9 diamet]1 w convey wat] "u a head ( #hj feet to z _m sets ( turb9e :eels 9 ! /ation4 ,^! :eels w drive t5 g5]ators ) an aggregate capacity ( #bd1jjj kil[atts or #cb1jjj horse-p[]4 ,sometimes ! slope 9 ! b$ ( a riv] is s gradual or s divid$ up betwe5 ! numb] ( small falls1 or ! volume ( wat] is s small1 t no v l>ge p[] c be develop$ at any "o po9t )\t ! con/ruction ( a long canal4 ,9 a case ( ?is sort electrical transmission is aga9 available to r$uce ! exp5se ( con/ruction t w make x possible to conc5trate all ! p[] f a long /ret* ( ! riv] at a s+le po9t4 ,?is is done by locat+ electric g5]at+ /ations at z _m po9ts z may be ?\ght desirable along ! riv] ^: en]gy is to be utiliz$1 & !n transmitt+ p[] f all ( ^! /ations to ! s+le po9t :]e x is want$4 ,a case 9 po9t is t ( ,g>v9s ,falls & ,hooksett ,falls on ! ,m]rimac ,riv] & f\r miles ap>t4 ,at ! =m] ( ^! two falls ! head ( wat] is tw5ty-eight feet1 & at ! latt] x is sixte5 feet4 ,to unite ! p[] ( bo? ^! falls 9 a s+le wat]-driv5 /ation w\ld obvi\sly require a canal f\r miles long ^: exp5se might well be prohibitive4 ,en]gy f bo? ^! falls is made available at a s+le sub-/ation 9 ,man*e/]1 ,n4 ,h41 by a g5]at+ plant at bo? po9ts & transmission l9es !nce to t city4 ,at ,hooksett ! pres5t capacity ( ! electric /ation is #a1jjj horse-p[]1 & at ,g>v9s ,falls ! capacity is #a1gjj horse-p[]4 ,! riv] is capable ( develop+ l>g] p[]s at bo? ( ^! falls1 h[ev]1 & con/ruction is n[ "u way at ,g>v9s t w raise its /ation capacity to #e1jjj horse-p[]4 ,a simil> result 9 ! comb9ation ( wat]-p[]s )\t ! aid ( a long canal is rea*$ 9 ! case ( ,gregg's ,falls & ,kelley's ,falls1 :i* are ?ree miles ap>t on ! ,piscataquog ,riv]4 ,at ! =m] ( ^! two falls ! electric g5]at+ capacity is #a1fjj horse-p[]1 z previ\sly not$1 & at ! latt] fall ! capacity is #a1jjj horse-p[]4 ,9 ea* case ! /ation is close to its dam1 & no canal is requir$4 ,electrical transmission unites ^! two p[]s 9 ! same sub-/ation at ,man*e/] t receives ! en]gy f ! two /ations above nam$ on ! ,m]rimac ,riv]4 ,in/ead ( transmitt+ p[] f two or m wat]falls to "s po9t di/ant f ea* ( !m1 ! p[] develop$ at "o or m falls may be transmitt$ to ! site ( ano!r & !re us$4 ,?is is1 9 fact1 done at ! ext5sive ,ludl[ tw9e mills on ! ,*icopee ,riv]1 9 ,massa*usetts4 ,^! mills are locat$ at a po9t on ! riv] :]e its fall makes ab\t #b1ejj horse-p[] available1 & ?is fall has be5 develop$ to its full capacity4 ,aft] a capacity ( #b1djj horse-p[] 9 /eam-eng9es _h be5 add$1 m wat]-p[] 0 s\ght1 & a new dam 0 locat$ on ! same riv] at a po9t ab\t #d4e miles up-/ream f ! mills4 ,! entire fl[ ( ! riv] 0 available at ?is new dam1 & a canal #d4e miles long might h be5 employ$ to c>ry ! wat] d[n to :eels at ! mills 9 ,ludl[4 ,su* a canal w\ld h meant a l>ge inve/m5t1 n only = l& & con/ruction1 b also1 possibly1 = damages to e/ates bord]+ on ! riv]1 if all ( its wat] 0 div]t$4 ,in/ead ( su* a canal1 an electric g5]at+ /ation 0 locat$ close to ! new dam ) a capacity ( #f1djj horse-p[]1 & ?is p[] is transmitt$ to motors 9 ! mills at ,ludl[4 ,ev5 :]e ! p[] is to be utiliz$ at "s po9t di/ant f ea* ( sev]al wat]falls1 x may be conv5i5t to comb9e ! p[] ( all at "o ( !m be=e transmitt+ x to ! place ( use4 ,?is is actually done 9 ! case ( two electric /ations locat$ respectively at ,indian ,or*>d & ,bir*em ,b5d on ! ,*icopee ,riv]1 ^: en]gy is deliv]$ to ! sub-/ation ( ! electrical supply sy/em 9 ,spr+field1 ,mass4 ,at ! ,indian ,or*>d /ation ! head ( wat] is #cf feet1 & at ,bir*em ,b5d x is #ad feet1 :ile ! two /ations are ab\t #b miles ap>t4 ,a canal ( ?is l5g? might h be5 built to give a head ( #ej feet at ! site ( ! ,bir*em ,b5d dam1 b in/ead ( ?is an electric /ation 0 locat$ ne> ea* fall1 & a transmission l9e 0 built betwe5 ! two /ations4 ,ea* g5]at+ /ation 0 also connect$ ) ! sub-/ation 9 ,spr+field by an indep5d5t l9e1 & p[] is n[ transmitt$ f "o g5]at+ plant to ! o!r1 z desir$1 & ! p[] ( bo? may g to ! sub-/ation ov] ei!r l9e4 ,9 ! ,indian ,or*>d /ation ! dynamo capacity is ab\t #b1jjj kil[atts1 & at ,bir*em ,b5d x is #hjj kil[atts4 ,ano!r case %[+ ! union ( two wat]-p[]s by electrical transmission1 :]e ! con/ruction ( an exp5sive canal 0 avoid$1 is t ( ! electrical supply sy/em ( ,h>t=d1 ,conn4 ,?is sy/em draws a l>ge "p ( its en]gy f two electric plants on ! ,f>m+ton ,riv]1 at po9ts t are ab\t #c miles ap>t 9 ! t[ns ( ,w9dsor & ,ea/ ,granby1 respectively4 ,at "o ( ^! plants ! head ( wat] is #cb feet1 & at ! o!r x is #bc feet1 s t head ( #ee feet might h be5 obta9$ by build+ a canal #c miles long4 ,ea* ( ^! /ations is locat$ ne> its dam1 & ! g5]ator capacity at "o /ation is #a1bjj & at ! o!r #a1ejj kil[atts4 ,transmission l9es deliv] p[] f bo? ( ^! plants to ! same sub-/ation 9 ,h>t=d4 ,sometimes two or m wat]-p[]s on ! same riv] t are to be unit$ are s f> ap>t t any attempt to con/ruct a canal betwe5 !m w\ld be impracticable4 ,?is is illu/rat$ by ! ,spi] & ,me*anicsville ,falls on ! ,hudson ,riv]1 :i* are #be miles ap>t 9 a direct l9e & at a great] di/ance by ! c\rse ( ! /ream4 ,at ,spi] ,falls ! head is #hj feet1 & at ,me*anicsville x is #ah feet4 ,union ( ! p[] ( ^! two falls is ?us out ( ! "q = physical reasons alone4 ,electrical transmission1 h[ev]1 br+s en]gy f bo? ( ^! wat]-p[]s to ! same sub-/ations 9 ,s*5ectady1 ,albany1 & ,troy4 ,9 ano!r class ( cases electrical transmission does :at c\ld n be done by any sy/em ( canals1 h[ev] exp5sive2 t is1 unites ! wat]-p[]s ( di/9ct & di/ant riv]s at any desir$ po9t4 ,?us p[] f bo? ! ,m]rimac & ! ,piscataquog riv]s is di/ribut$ ov] ! same wires 9 ,man*e/]2 ! ,yuba & ! ,mokelumne contribute to electrical supply along ! /reets ( ,san ,francisco2 & ! ,monte ,alto & ,tlalnepantla yield en]gy 9 ! ,city ( ,mexico4 ,x does n foll[ f ! =ego+ t x is always m economical to develop two or m small] wat]-p[]s at diff]5t po9ts along a riv] = transmission to "s common c5tre ?an x is to conc5trate ! wat] at a s+le l>g] /ation by m elaborate hydraulic con/ruction1 & !n deliv] all ( ! en]gy ov] a s+le transmission l9e4 ,! s+le l>g] hydraulic & electric plant w usually h a fir/ co/ l>g] ?an t ( ! sev]al small] ones1 because ( ! requir$ canals or pipe l9es4 ,a p>tial (fset to ?is l>g] hydraulic inve/m5t is ! diff]5ce 9 co/ betwe5 "o & sev]al transmission l9es1 or at lea/ ! co/ ( ! l9es t w\ld be necess>y betwe5 ! sev]al small] /ations 9 ord] to comb9e _! en]gy output be=e its transmission ov] a s+le l9e to ! po9t ( use4 ,aga9/ ! total excess ( co/ = ! s+le l>g] hydraulic & electrical plant !re %\ld be set ! great] exp5se ( op]ation at sev]al small] & sep>ate plants4 ,ev5 a small wat]-driv5 electric /ation t c be op]at$ by a s+le att5dant at any "o "t mu/ h two att5dants if x is to deliv] en]gy dur+ ! great] "p or all ( e tw5ty-f\r h\rs4 ,b a s+le att5dant c c>e = a wat]-p[] plant ( #b1jjj horse-p[] or m capacity1 s t two plants ( #gej horse-p[] ea* w require d\ble ! op]at+ =ce ( "o plant ( #a1ejj horse-p[]4 ,if two su* plants are con/ruct$ in/ead ( "o t has _! comb9$ capacity1 ! mon?ly wages ( ! two additional op]ators w am\nt to at lea/ "o hundr$ doll>s4 ,if money is wor? six p] c5t ye>ly1 x foll[s t an additional inve/m5t ( #a1bjj #j4jf #bj1jjj might be made 9 hydraulic "w to conc5trate ! p[] at "o po9t be=e ! annual int]e/ *>ge w\ld equal ! increase ( wages made necess>y by two plants4 ,reliability ( op]ation is "o ( ! mo/ important requirem5ts 9 an electric wat]-p[] plant1 & its con/ruction %\ld be c>ri$ out ) ?is 9 view4 ,an*or ice is a s]i\s m5ace to ! regul> op]ation ( wat]-:eels 9 cold climates1 because x clogs up ! op5+s 9 ! racks & 9 ! :eel passages4 ,an*or ice is =m$ 9 small p>ticles 9 ! wat] ( %all[ & fa/-fl[+ /reams1 & t5ds to =m into masses on solid sub/ances ) :i* ! wat] comes 9 contact4 ,at ! entrance to p5/ocks or :eel *amb]s1 /eel racks ) long1 n>r[ op5+s1 say "o & "o-qu>t] in*es wide1 are regul>ly plac$ to keep all float+ objects away f ! :eels4 ,:5 wat] be>+ f9e an*or or frazil ice comes 9 contact ) ^! racks1 x rapidly clogs up ! n>r[ op5+s betwe5 ! b>s1 unless m5 are kept at "w rak+ (f ! ice z x =ms4 ,at ! ,niag>a ,falls electric /ation1 9 "s in/ances1 :5 ! racks become clogg$1 !y h be5 lift$1 & ! an*or ice all[$ to pass d[n ?r\gh ! :eels4 ,?is is said to h prov$ an effective rem$y1 b x w\ld obvi\sly be ( no avail 9 a case :]e ! ice clogg$ ! passages ( ! :eels !mselves4 ,! be/ safegu>d aga9/ an*or ice is a l>ge1 deep =ebay next to ! racks1 :]e ! wat]1 be+ comp>atively quiet1 w soon freeze ov] aft] cold wea!r comm5ces4 ,! an*or ice com+ d[n to ?is =ebay & los+ mo/ ( its =w>d motion1 soon rises to ! surface or to ! "u side ( ! top coat+ ( solid ice1 & ! w>m] wat] s9ks to ! bottom4 ,good con/ruction puts ! entrance ends ( p5/ocks well bel[ ! surface ( wat] 9 ! =ebay1 s t !y may receive ! w>m] wat] t conta9s little or no an*or ice4 ,illu/ration3 ,,fig4 #g4--;,cross ,section ( ,dike on ,*icopee ,riv] at ,r$ ,bridge4 ,illu/rations ( practice along ^! l9es1 z to size1 dep? ( =ebay1 & location ( p5/ocks may be se5 9 _m well-design$ plants4 ,"o in/ance is t at ,g>v9s ,falls1 on ! ,m]rimac ,riv]1 :]e ! new hydraulic developm5t = #e1jjj horse-p[] is n[ "u way4 ,wat] f ! riv] 9 ?is case comes d[n to ! p[]-/ation ?r\gh a canal #ejj feet long1 & ( #fh feet av]age wid? midway betwe5 ! bottom & ! normal fl[ l9e4 ,9 dep? up to 8 fl[ l9e ! canal is #ab feet at its upp] & #ac feet at its l[] end1 j be=e x wid5s into ! =ebay4 ,9 ?is =ebay ! dep? increases to #ag feet1 & ! wid? at ! rack is d\ble t ( ! canal4 ,! /eel p5/ocks1 ea* #ab feet 9 diamet]1 t]m9ate 9 ! =ebay wall at an av]age di/ance ( #g feet beh9d ! rack1 & ea* p5/ock has its c5tre #aj4f feet bel[ ! wat] level 9 ! =ebay4 ,z !re is a l>ge pond creat$ by ! dam 9 ?is case1 & z ! fl[ ( wat] 9 ! canal is deep r ?an swift1 en\gh opportunity is probably af=d$ = any an*or ice to rise to ! surface be=e x rea*es ! =ebay 9 ?is case4 ,p5/ocks = ! electric /ation at ,great ,falls1 on ! ,presumpscot ,riv]1 :5ce en]gy is drawn = light+ & p[] 9 ,portl&1 ,me41 are ea* #h feet 9 diamet]1 & pi]ce ! =ebay wall beh9d ! rack ) _! c5tres #ae feet bel[ ! normal wat] level 9 ! =ebay4 ,9 front ( ! =ebay wall ! wat] /&s #bg feet deep1 & ! pond =m$ by ! dam1 ( :i* ! =ebay wall =ms "o section1 is #a1jjj feet wide & v quiet4 ,?\gh ! ,ma9e climate is v cold 9 w9t] & ! ,presumpscot is a turbul5t /ream above ! dam & pond1 !re has nev] be5 any tr\ble ) an*or ice at ! ,great ,falls plant4 ,an excell5t illu/ration is ?us pres5t$ ( ! fact t deep1 /ill wat] 9 ! =ebay is a rem$y = tr\bles ) ice ( ?is sort4 ,maximum loads on electrical supply sy/ems are usually f twice to f\r times z great z ! av]age loads dur+ ea* tw5ty-f\r h\rs4 ,a pure light+ s]vice t5ds t[>d ! l>g] ratio betwe5 ! av]age & maximum load1 :ile a l>g] motor capacity along ) ! lamps1 t5ds to r$uce ! ratio4 ,fur!rmore1 by f> ! great] "p ( ! en]gy output ( an electrical supply sy/em dur+ ea* tw5ty-f\r h\rs mu/ be deliv]$ betwe5 noon & midnight4 ,= ^! reasons !re mu/ be en\gh wat] /or$1 t c fl[ to ! /ation z want$1 to c>ry a l>ge %>e ( ! load dur+ ea* day1 unless /orage batt]ies are employ$ to absorb en]gy at times ( light load1 if ! entire normal fl[ ( ! riv] is to be utiliz$4 ,x is usually mu* *eap] to /ore wat] ?an electrical en]gy = ! daily fluctuations ( load1 & ! only practicable place = ?is /orage is mo/ commonly beh9d ! dam t ma9ta9s ! head = ! p[]-/ation4 ,?is /orage space %\ld be s l>ge t ! dra9 ^u x dur+ ! h\rs ( heavy load w l[] ! head ( wat] on ! :eels b little1 else x may be h>d to ma9ta9 ! /&>d spe$ ( revolution = ! :eels & g5]ators1 & consequ5tly ! transmission voltage4 ,illu/ration3 ,,fig4 #h4--,valley ,flood$ above ,spi] ,falls on ! ,hudson ,riv]4 ,at ! ,great ,falls plant1 wat] /orage to provide = ! fluctuations ( load 9 diff]5t p>ts ( ! day takes place back ( ! dam1 & = ab\t "o mile up-/ream4 ,?is dam is #dej feet long 9 its ma9 "p1 & a reta9+ wall increases ! total l5g? to ab\t #a1jjj feet4 ,= half a mile up-/ream f ?is dike & dam ! av]age wid? ( ! pond is #a1jjj feet1 & its greate/ dep? is n less ?an #bg feet4 ,z ! /ation capacity is #b1gjj horse-p[] 9 ma9 g5]ators1 ) a head ( #ce feet at ! :eels ! /orage capacity is m ?an ample = all *anges ( load at diff]5t times ( day4 ,! dam at ,spi] ,falls1 on ! ,hudson ,riv]1 is #a1hbj feet long betwe5 banks1 #aee feet high above b$rock 9 its deepe/ section1 & raises ! riv] #ej feet above its =m] level4 ,beh9d ! dam a lake is =m$ "o-?ird ( a mile wide & #e miles long4 ,wat] f ?is /orage res]voir passes d[n ?r\gh ! turb9es ) a head ( #hj feet1 & is to develop #cb1jjj horse-p[]4 ,z a little calculation w %[1 ?is lake is ample to ma9ta9 ! head "u any fluctuation 9 ! daily load4 ,at ,caon ,f]ry1 :]e electrical en]gy = ,butte & ,hel5a1 ,mont41 is develop$1 ! dam1 :i* is #dhj feet long1 crosses ! riv] 9 a n>r[ canyon t ext5ds up-/ream = ab\t half a mile4 ,above ?is canyon ! riv] valley wid5s out1 & ! dam1 :i* ma9ta9s a head ( #cj feet at ! p[]-/ation1 sets back ! wat] 9 ?is valley1 & ?us =ms a lake betwe5 two & ?ree miles wide & ab\t sev5 miles long4 ,at ! /ation ! g5]ator equipm5t has a total rat+ ( #aj1jjj horse-p[]4 ,f ^! figures x may be se5 t ! /orage lake w\ld be able to ma9ta9 ne>ly ! normal head ( wat] = "s h\rs1 :5 ! /ation 0 op]at+ "u full load1 h[ev] small ! fl[ ( ! riv] above4 ,illu/ration3 ,,fig4 #i4--;,canal at ,bulls ,bridge on ,h\satonic ,riv]4 ,,*apt] ,,vii4 ,,! ,,location ,,( ,,electric ,,wat]-,,p[] ,,/ations4 ,co/ ( wat]-p[] developm5t dep5ds1 9 l>ge measure1 on ! location ( ! electric /ation t is to be op]at$4 ,! =m ( su* a /ation1 its co/1 & ! type ( g5]at+ app>atus to be employ$ are also mu* influ5c$ by ! site select$ = x4 ,?is site may be exactly at1 or f> remov$ f1 ! po9t :]e wat] t is to pass ?r\gh ! :eels is div]t$ f its natural c\rse4 ,a unique example ( a location ( ! =m] k9d is to be f\nd ne> ,burl+ton1 ,vt41 :]e ! electric /ation is itself a dam1 be+ built entirely across ! natural b$ ( "o arm ( ! ,w9ooski ,riv] at a po9t :]e an isl& ne> its c5tre divides ! /ream into two p>ts4 ,! riv] at ?is po9t has cut its way d[n ?r\gh solid rock1 leav+ p]p5dicul> walls on ei!r side4 ,up f ! l$ge t =ms ! b$ ( ! /ream1 & into ! rocky walls1 ! p[]-/ation1 ab\t #aaj feet long1 is built4 ,! up-/ream wall ( ?is /ation is built aft] ! fa%ion ( a dam1 & is ren=c$ by ! d[n-/ream wall1 & ! wat] fl[s directly ?r\gh ! p[]-/ation by way ( ! :eels4 ,a con/ruction ( ?is sort is all t c\ld well be atta9$ 9 ! way ( economy1 !re be+ nei!r canal nor long p5/ocks1 & only "o wall ( a p[]-h\se ap>t f ! dam4 ,on ! o!r h&1 ! location ( a /ation directly across ! b$ ( a riv] 9 ?is way makes x impossible to protect ! ma*9]y if ! up-/ream wall1 :i* acts z ! dam1 %\ld ev] give way4 ,! peculi> natural conditions favorable to ! con/ruction j consid]$ are seldom f\nd4 ,illu/ration3 ,,fig4 #aj4--,p[]-h\se on ! ,w9ooski ,riv]1 ne> ,burl+ton1 ,vt4 ,"o ( ! mo/ common locations = an electric wat]-p[] /ation is at "o side ( a riv]1 directly 9 front ( "o end ( ! dam & close to ! foot ( ! falls4 ,a location ( ?is k9d 0 adopt$ = ! /ation at ,gregg's ,falls1 "o ( ! wat]-p[]s includ$ 9 ! electric sy/em ( ,man*e/]1 ,n4 ,h41 :]e ! spray ( ! fall rises ov] ! ro( ( ! /ation4 ,two %ort /eel p5/ocks1 ea* t5 feet 9 diamet]1 convey ! wat] f ! =ebay section ( ! dam to :eels 9 ! /ation ) a head ( fifty-"o feet4 ,illu/ration3 ,,fig4 #aa4--;,canal & ,p[]-h\se on ,/4 ,joseph ,riv]1 ,bu*anan1 ,mi*4 ,a simil> location 0 select$ = ! /ation at ,great ,falls1 on ! ,presumpscot ,riv] 7see cuts71 :5ce electrical en]gy is deliv]$ 9 ,portl&1 ,me4 ,f\r /eel p5/ocks1 a few feet long & ea* eight feet 9 diamet]1 br+ ! wat] 9 ?is case f ! =ebay section ( ! dam to ! :eel cases 9 ! p[]-h\se4 ,illu/ration3 ,,fig4 #ab4--,p[]-h\se on ,hudson ,riv] at ,me*anicsville4 ,:]e ! p[]-/ation is locat$ at ! foot ( ! dam1 z j describ$1 t "p :i* s]ves z a =ebay wall usually c>ries a head gate = ea* p5/ock4 ,! ov]fall section ( a dam may give way 9 cases l ! two j not$ )\t necess>ily de/roy+ ! p[]-/ation1 b 9 times ( fre%et or v high wat] ! /ation may be flood$ & its op]ation /opp$4 ,! risk ( any su* flood+ w v>y greatly on diff]5t riv]s1 & 9 p>ticul> cases may be v slight4 ,location ( ! g5]at+ /ation close to ! foot ( ! dam at "o end obvi\sly avoids all exp5se = a canal & cuts ! co/ ( p5/ocks d[n to a v l[ figure4 ,su* locations = /ations are n limit$ to falls ( any p>ticul> height1 & ! %ort p5/ocks usually ent] ! dam ne>] its base ?an its top & pass to ! /ation at only a slight incl9ation f ! horizontal4 ,at ,great ,falls1 above m5tion$1 ! head ( wat] is ?irty-sev5 feet4 ,a %ort canal is con/ruct$ 9 "s cases f "o end ( a dam to a little di/ance d[n-/ream1 t]m9at+ at a favorable site = ! electric /ation4 ,con/ruction ( ?is sort 0 adopt$ at ! ,bir*em ,b5d ,falls ( ! ,*icopee ,riv]1 :5ce en]gy is suppli$ to ,spr+field1 ,mass4 ,^! falls furni% a head ( f\rte5 feet1 & ! wat]-:eels are locat$ on ! floor ( ! op5 canal at its end4 ,! p[]-/ation is on ! %ore side ( ?is canal1 & ! %afts ( ! wat]-:eels ext5d ?r\gh bu%+s 9 ! canal wall1 :i* =ms ! l[] "p ( "o side ( ! /ation1 to connect ) ! electric g5]ators inside4 ,?is r unusual location ( wat]-:eels has at lea/ ! obvi\s advantage t !y require no room inside ( ! /ation4 ,fur!rmore1 z ! canal is betwe5 ! /ation & ! riv]1 any break 9 ! canal is n apt to flood ! /ation4 ,illu/ration3 ,,fig4 #ac4--,york ,hav5 ,p[]-h\se1 on ,susquehanna ,riv]1 ,p5nsylvania4 ,an illu/ration ( ! use ( a v %ort canal to convey wat] f "o end ( a dam to a p[]-/ation exi/s 9 ! #aj1jjj horse-p[] plant at ,caon ,f]ry1 ,mont41 :]e ! head ( wat] is ?irty feet4 ,9 ?is case ! masonry canal is b little long] ?an ! p[]-h\se1 & ?is latt] sits squ>ely betwe5 ! canal & ! riv]1 virtually at ! foot ( ! falls4 ,o!r examples ( ! location ( g5]at+ /ations betwe5 %ort canals & ! riv] may be se5 at ,concord1 ,n4 ,h41 :]e ! head ( wat] is sixte5 feet2 at ,lewi/on1 ,me41 :]e ! head is ?irty-two feet2 & at ,spi] ,falls1 on ! ,hudson ,riv]1 ,new ,york1 :]e !re is a head ( eighty feet4 ,!re is "s ga9 9 security 9 _m cases by locat+ ! p[]-/ation sev]al hundr$ feet f ! dam & a little to "o side ( ! ma9 riv] *annel4 ,= su* cases a canal may be *eap] ?an /eel p5/ocks :5 ! items ( depreciation & repairs are tak5 into acc\nt4 ,aside f ! "q ( great] security = ! /ation 9 ! ev5t ( a break 9 ! dam1 x is necess>y 9 _m cases to convey ! wat] a l>ge fraction ( a mile1 or ev5 a numb] ( miles1 f ! po9t :]e x leaves its natural c\rse to t :]e ! p[]-/ation %\ld be locat$4 ,an example 9 po9t exi/s at ,spr+field1 ,mass41 :]e "o ( ! electric wat]-p[] /ations is locat$ ab\t #a1djj feet d[n-/ream f a fall ( ?irty-six feet 9 ! ,*icopee ,riv]1 because l& close to ! falls 0 all occupi$ at ! "t ! electric /ation 0 built4 ,illu/ration3 ,,fig4 #ad4--,p[]-h\se at ,caon ,f]ry on ! ,miss\ri ,riv]4 ,illu/ration3 ,,fig4 #ae4--,%aw9igan ,falls ,p[]-plant4 ,! ,%aw9igan ,falls ( ! ,/4 ,maurice ,riv] 9 ,canada occur at two po9ts a %ort di/ance ap>t1 ! fall at "o po9t be+ ab\t #ej & at ! o!r #ajj feet high4 ,a canal #a1jjj feet long takes wat] f ! riv] above ! upp] ( ^! falls & deliv]s x ne> to ! electric p[]-h\se on ! riv] bank bel[ ! l[] falls4 ,9 ?is way a head ( #abe feet is obta9$ at ! p[]-h\se4 ,! canal 9 ?is case ends on high gr\nd #acj feet f ! p[]-h\se1 & ! wat] passes d[n to ! :eels ?r\gh /eel p5/ocks #i feet 9 diamet]4 ,illu/ration3 ,,fig4 #af4--,p[]-h\se on ,:ite ,riv]1 ,oregon4 ,ano!r int]e/+ example ( conditions t require a p[]-h\se to be locat$ "s di/ance f ! po9t :]e wat] is div]t$ f its natural c\rse may be se5 at ! falls on ! ,apple ,riv]1 :5ce en]gy is transmitt$ to ,/4 ,paul1 ,m9n4 ,by means ( a natural fall ( #cj feet1 a dam #dg feet high "s di/ance up-/ream1 & "s rapids 9 ! riv]1 x 0 !re possible to obta9 a total fall ( #hb feet4 ,to utilize ?is entire fall a timb] flume1 #a1eej feet 9 l5g?1 0 built f ! dam to a po9t ne> ! p[]-h\se on ! riv] bank & bel[ ! falls & rapids4 ,! flume 0 connect$ ) ! :eels1 #hb feet bel[1 by a /eel p5/ock #cac feet long & #ab feet 9 diamet]4 ,z ! ,/4 ,m>y's ,riv] leaves ,lake ,sup]ior x passes ov] a s]ies ( rapids ab\t half a mile 9 l5g?1 fall+ tw5ty feet 9 t di/ance4 ,to make ! p[] ( ?is great volume ( wat] available1 a canal #ac1jjj feet long 0 excavat$ f ! lake to a po9t on ! riv] bank bel[ ! rapids4 ,betwe5 ! end ( ! canal & ! riv] sits ! p[]-/ation1 act+ z a dam1 & ! wat] passes d[n ?r\gh x & ! :eels "u a head ( tw5ty feet4 ,illu/ration3 ,,fig4 #ag4--,p[]-h\se ,across ,canal at ,sault ,/e4 ,m>ie1 ,mi*4 ,by means ( a canal #af1bjj feet long f ! ,/4 ,lawr5ce ,riv] a head ( wat] am\nt+ to fifty feet has be5 made available at a po9t on ! bank ( ,grass ,riv] ne> ,mass5a1 ,n4 ,y4 ,!re aga9 ! p[]-/ation acts z a dam1 & ! canal wat] passes d[n ?r\gh x to rea* ! riv]4 ,illu/ration3 ,,fig4 #ah4--;,canal & ,/ation on ,payette ,riv]1 ,idaho4 ,f ^! illu/rations x may be se5 t 9 _m cases1 9 comp>atively level c\ntry1 a wat]-p[] c be fully develop$ only by means ( canals or pipe l9es1 & ! g5]at+ /ations _c be locat$ at ! po9ts :]e ! wat] is div]t$4 ,?us f> ! cases consid]$ h be5 only ^? ) mod]ate heads & r l>ge volumes ( wat]4 ,9 m\nta9\s c\ntry1 :]e riv]s are comp>atively small & _! c\rses are m>k$ by num]\s falls & rapids1 x is g5]ally necess>y to utilize ! fall ( a /ream ?r\gh "s miles ( its l5g? 9 ord] to effect a satisfactory developm5t ( p[]4 ,to rea* ?is result1 r long canals1 flumes1 or pipe l9es mu/ be utiliz$ to convey ! wat] to p[]-/ations & deliv] x at high pressures4 ,9 cases ( ?is k9d ! co/ ( ! canal or pipe l9e may be ! l>ge/ item 9 ! p[] developm5t1 & x may be an important "q :e!r ?is co/ %\ld be r$uc$ or avoid$ by ! erection ( sev]al small g5]at+ plants in/ead ( "o l>ge "o4 ,cali=nia (f]s num]\s examples ( electric-p[] developm5t ) wat] t has be5 c>ri$ sev]al miles ?r\gh artificial *annels4 ,an illu/ration ( ?is class ( "w exi/s at ! ,electra p[]-h\se on ! bank ( ! ,mokelumne ,riv]1 9 ! ,si]ra ,nevada ,m\nta9s4 ,wat] is suppli$ to ! :eels 9 ?is /ation "u a head ( #a1dej feet ?r\gh pipes #c1fjj feet long lead+ to ! top ( a ne>-by hill4 ,to rea* ?is hill ! wat]1 aft] its div]sion f ! ,mokelumne ,riv] at ! dam1 fl[s tw5ty miles ?r\gh a canal or dit* & !n ?r\gh #c1jjj feet ( wood5 /ave pipe4 ,ano!r example ( ! same sort may be se5 9 ! p[]-h\se at ,colgate1 on ! ,nor? ,yuba ,riv]1 9 ! *a9 ( m\nta9s above nam$4 ,wat] tak5 f ?is riv] passes ?r\gh a wood5 flume ne>ly eight miles long to ! side ( a hill #gjj feet above ! p[]-h\se1 & !nce d[n to ! :eels ?r\gh /eel & ca/-iron pipes1 five 9 numb] & ?irty in*es ea* 9 diamet]4 ,ev5 ) long flumes1 canals1 & pipe l9es1 x may be necess>y to locate a numb] ( g5]at+ /ations along a s+le riv] ( ! class n[ "u consid]ation 9 ord] to utilize its entire p[]4 ,?us on ! ,k]n ,riv]1 :i* rises 9 ! ,si]ra ,nevada ,m\nta9s & empties into ,tul>e ,lake1 two electric p[]-/ations are "u con/ruction1 & surveys are be+ made = ?ree m4 ,( ^! /ations1 ! "o at ! l[e/ level w op]ate "u an #hgb-;foot head ( wat]1 & ?is wat]1 aft] its div]sion f ! riv]1 w pass ?r\gh tw5ty-"o tunnels1 ) an aggregate l5g? ( ab\t t5 miles1 & ?r\gh six flumes m\nt$ on tre/les & hav+ a total l5g? ( #a1gjc feet4 ,next up-/ream is a /ation ne> ! po9t :]e wat] is div]t$ = ! plant j nam$4 ,?is second /ation w "w "u a head ( #cag feet1 & wat] = x w come f a po9t f>!r up-/ream by canals1 tunnels1 & flumes1 ) an aggregate l5g? ( elev5 & "o-half miles4 ,at ?ree po9ts /ill high] up on ?is riv] x is ! int5tion to locate ?ree o!r p[]-/ations by conduct+ ! wat] 9 artificial *annels1 ab\t twelve & "o-half1 fifte51 & tw5ty miles 9 l5g? respectively4 ,f>!r s\? 9 ,cali=nia1 on ! ,santa ,ana ,riv] & ,mill ,creek1 ext5sive p[] developm5ts on ! l9es j indicat$ h be5 c>ri$ out4 ,on ,mill ,creek1 ab\t six miles f ! city ( ,r$l&s1 is an electric /ation op]at+ "u a head ( #ecj feet1 ) wat] 9 "p div]t$ f ! /ream a little less ?an two miles above & br\ght d[n ?r\gh a /eel pipe #aj1bej feet long & ?irty in*es 9 diamet]4 ,?is pipe l9e also takes wat] f ! tail race ( ano!r g5]at+ plant at its upp] end4 ,) "s additions & modifications1 ! /ation j describ$ is ! fam\s ,r$l&s plant1 built 9 #ahic1 & believ$ to be ! fir/ = ?ree-phase transmission 9 ! ,unit$ ,/ates4 ,illu/ration3 ,,fig4 #ai4--;,canal & ,p[]-/ation on ,nev]s9k ,riv]1 ,new ,york4 ,at ! upp] end ( ! pipe l9e j nam$ ! second /ation op]ates1 9 "p1 ) wat] drawn f ,mill ,creek ?r\gh a comb9ation ( tunnels1 flumes1 & cem5t & /eel pipes1 ) a comb9$ l5g? ( ab\t ?ree miles1 & deliv]$ to "s ( ! :eels ) a head ( #fbg feet4 ,! o!r :eels at ?is plant receive wat] drawn f ! same creek by a pipe l9e ab\t six miles long4 ,a l>ge "p ( ?is l9e is compos$ ( #ca-;in* cem5t pipe1 laid 9 tr5*es & tunnels4 ,! wat] 9 ! #h1jjj feet ( pipe next to ! p[]-h\se has a fall ( #a1ifj feet1 & ?is pipe is ( /eel & #bd & #bf in*es 9 diamet]4 ,! head ( #a1ifj feet1 m9us friction losses 9 ! /eel pipes1 is deliv]$ at ! :eels4 ,f ! =ego+ x appe>s t 9 a space ( eight miles along ,mill ,creek !re is a fall ( m ?an #b1dij feet4 ,to utilize ?is fall1 wat] is div]t$ f ! creek at ?ree po9ts )9 a di/ance ( six miles & deliv]$ 9 two p[]-/ations "u ?ree diff]5t heads4 ,z ! /ream ga!rs 9 volume betwe5 ! upp] & ! l[] intakes1 an equal am\nt ( p[] c\ld h be5 develop$ 9 a s+le /ation only by tak+ ! ?ree sep>ate conduits or pipe l9es to x & deliv]+ _! wat] !re at ?ree heads4 ,:e!r ! exp5se ( ext5d+ conduits & pipe l9es to a s+le g5]at+ /ation w m ?an (fset ! advantages to be ga9$ !reby is a "q t %\ld be decid$ on a numb] ( factors v>y+ ) ea* case4 ,9 g5]al1 x may be said t ! small] ! volume ( wat] to be h&l$ & ! great] its head1 ! m advantage\s is x to conc5trate ! g5]at+ ma*9]y 9 ! smalle/ practicable numb] ( /ations4 ,on ! ,santa ,ana ,riv]1 into :i* ,mill ,creek fl[s1 ! ,santa ,ana plant1 :5ce en]gy is transmitt$ to ,los ,angeles1 is locat$4 ,wat] rea*es ?is plant ?r\gh a conduit ( tunnels1 flumes1 & pipes1 ) a total l5g? ( ab\t ?ree miles f ! po9t :]e ! fl[ ( ! riv] is div]t$4 ,! #b1baj feet ( ?is conduit ne>e/ ! p[]-plant are compos$ ( #cj-;in* /eel pipe1 ) a fall ( #gbh feet4 ,)9 fifte5 miles ( ,mexico ,city are five wat]-p[] /ations t supply en]gy = its electrical sy/em4 ,two ( ^! /ations are on ! ,monte ,alto & ?ree are on ! ,tlalnepantla ,riv]1 ! two =m] /ations be+ ab\t ?ree miles1 & ! m di/ant ( ! ?ree latt] /ations five miles1 ap>t4 ,at a di/ance ( sev]al miles above ! highe/ /ation on ea* riv] ! wat] is div]t$ by a canal1 & ! wat] ( ea* ( ^! canals1 aft] pass+ ?r\gh ! :eels ( ! highe/ /ation1 goes on to ! rema9+ /ation1 or /ations1 on ! same riv] by a cont9uation ( ! canal4 ,illu/ration3 ,,fig4 #bj4--,wood ,pipe ,l9e to ,pike's ,peak ,p[]-h\se4 ,by plac+ ! /ations s %ort a di/ance ap>t ! head ( wat] at ea* /ation is r$uc$4 ,on "o /ream ^! heads are #dib & #eid feet respectively1 & at two ( ! /ations on ! o!r /ream !y are #edg & #bie feet respectively4 ,?is division ( ! total head ( wat] af=d$ by ea* riv] results 9 a r small capacity = ea* /ation1 ! total at ! five plants be+ only #d1bbe kil[atts4 ,9 contra/ ) ?is figure ! already m5tion$ ,electra plant has g5]ators ( #aj1jjj1 ! ,santa ,ana plant g5]ators ( #c1jjj1 & ! l>g] ( ! two ,mill ,creek plants g5]ators ( #c1ejj kil[atts capacity4 ,x %\ld be not$ t ! co/ ( op]ation1 z well z t ( orig9al con/ruction1 w v>y mat]ially betwe5 "o l>ge & sev]al small] /ations ( equal total capacity1 ! advantage z to op]ative co/ be+ obvi\sly ) ! "o l>ge plant4 ,illu/ration3 ,,fig4 #ba4--,p[]-h\se at ,great ,falls1 ,presumpscot ,riv]4 ,all ( ! p[]-/ations "h consid]$ h be5 equipp$ ) wat]-:eels & g5]ators op]at+ on horizontal %afts1 & ?is is ! g5]al practice4 ,?is arrangem5t br+s ! g5]ators & ! floor ( ! p[]-/ation )9 a few feet ( ! level ( ! tail-wat]4 ,by ! g5]al use ( draught tubes ) turb9e :eels ! floors ( /ations are (t5 kept tw5ty feet or m above ! tail-wat] level4 ,:]e ! total available head ( wat] is q small1 z is (t5 ! case ) riv]s :]e ! volume ( wat] is great1 x is g5]ally necess>y to br+ ! level ( ! /ation floor d[n to )9 a few feet ( ! tail-wat]4 ,! ,bir*em ,b5d /ation ( ! ,spr+field1 ,mass41 electric sy/em af=ds a good example ( ?is sort1 ! floor ( ?is /ation be+ only #b4f feet above ! ord9>y level ( ! tail-wat]4 ,at ?is /ation ! diff]5ce ( level betwe5 ! head- & tail-wat] is only f\rte5 feet1 & ev5 ) ! l[ floor level nam$ ! top sides ( ! horizontal turb9e :eels are cov]$ only by #d4e feet ( wat]4 ,at ! ,g>v9's ,falls /ation ( ! ,man*e/]1 ,n4 ,h41 electric sy/em ! level ( ! floor ( ! g5]ator room is ?irte5 feet above ! ord9>y level ( ! ,m]rimac ,riv]1 on ! bank ( :i* ?is /ation is locat$2 b 9 ?is case ! total head ( wat] is ab\t tw5ty-eight feet4 ,! high wat] ( ! ,m]rimac 9 #ahif1 be=e ! ,g>v9's ,falls /ation 0 built1 rea*$ a po9t #e4bd feet above its pres5t floor level1 & #ah4bd feet above ! ord9>y level ( ! riv] at ! po9t :]e ! /ation is locat$4 ,"u ! ,r$ ,bridge electric /ation ( ! ,ludl[ ,manufactur+ ,company1 on ! ,*icopee ,riv]1 9 ,massa*usetts1 ! tail-wat] is tw5ty feet bel[ ! level ( ! floor & tw5ty-f\r feet bel[ ! c5tres ( ! wat]-:eel & g5]ator %afts4 ,! diff]5ce betwe5 :eel-%aft & tail-wat] levels at ?is /ation is ne> ! maximum t c be atta9$ ) horizontal pressure turb9es1 because a draught tube mu* long] ?an tw5ty-five feet does n give good results4 ,9 a pressure turb9e ! guides & :eel mu/ be completely fill$ ) wat]1 z mu/ also ! draught tube1 = effici5t op]ation4 ,if draught tubes are mu* m ?an tw5ty-five feet long1 x is h>d to keep a solid column ( wat] f turb9e to tail-wat] 9 ea*1 & if ?is is n done a "p ( ! head ( wat] becomes ineffective4 ,z pressure turb9es are employ$ almo/ exclusively at electric /ations ) l[ heads ( wat]1 x is frequ5tly impossible to locate su* /ations above ! possible level ( tail-wat] 9 times ( flood if horizontal :eels direct-connect$ to g5]ators are employ$4 ,illu/ration3 ,,fig4 #bb4--,p[]-h\se at ,g>v9's ,falls on ! ,m]rimac ,riv]4 ,if turb9es ) v]tical %afts are to be us$1 a p[]-/ation may be s locat$ or con/ruct$ t all ! electrical equipm5t w be above ! highe/ kn[n wat]-m>k4 ,) v]tical %afts1 connect+ :eels1 & g5]ators1 ! ma9 floor ( an electric /ation may be locat$ above ! cre/ ( ! falls :]e ! p[] is develop$ in/ead ( at or ne> _! base4 ,illu/ration3 ,,fig4 #bc4--,p[]-h\se ,no4 #b at ,niag>a ,falls4 ,by f> ! mo/ important examples ( electric /ations laid out on ?is plan are ^? at ,niag>a ,falls1 :]e !re are f\r su* plants4 ,two ( ^! g5]at+ plants1 ) an aggregate capacity ( #aje1jjj horse-p[]1 /& a mile above ! falls1 & are suppli$ ) wat] ?r\gh a %ort canal f ,niag>a ,riv]4 ,b5ea? ea* ( ^! two /ations a long1 n>r[ :eel pit has be5 excavat$ ?r\gh rock to a dep? ( #agb feet bel[ ! level ( wat] 9 ! canal4 ,bo? :eel pits t]m9ate 9 a tunnel #g1jjj feet long t op5s into ! riv] bel[ ! falls4 ,9 ?is :eel pit ! tail-wat] level is #afa feet bel[ t ( ! wat] 9 ! canal1 & #aff feet bel[ ! floor ( ! p[]-/ation4 ,wat] passes f ! canal d[n ! :eel pits to ! :eels ne> ! bottom ?r\gh /eel p5/ocks1 ea* sev5 feet 9 diamet]1 & a v]tical %aft ext5ds f ea* :eel case to a g5]ator 9 ! /ation above4 ,locations l t at ,niag>a give great security aga9/ high wat] & wa%\ts1 b are seldom adopt$ because ( ! l>ge fir/ co/ ( plant con/ruction4 ,) heads ( wat] f sev]al hundr$ to #b1jjj feet ! loss ( a few feet ( head r$uces ! available p[] to only a v slight ext5t1 & impulse :eels are usually employ$4 ,draught tubes are n available to increase ! heads at su* :eels1 & any fall ( ! wat] aft] x leaves ! :eels does no useful "w4 ,illu/ration3 ,,fig4 #bd4--;,colgate ,p[]-h\se4 ,electric /ations driv5 by impulse :eels "u great heads1 l ^? at ,colgate1 ,electra1 ,k]n ,riv]1 ,santa ,ana ,riv]1 & ,mill ,creek1 may be locat$ f> en\gh above ! b$s ( _! wat]-c\rses to avoid dang]s f fre%ets1 )\t s]i\s loss ( available p[]4 ,,*apt] ,,viii4 ,,design ,,( ,,electric ,,wat]-,,p[] ,,/ations4 ,illu/ration3 ,,fig4 #be4--;,cross ,section ( ,columbus1 ,ga41 ,p[]-/ation4 ,wat]-:eels mu/ be locat$ at "s elevation betwe5 t ( head- & tail-wat]4 ,) horizontal %afts & direct-connect$ :eels & g5]ators ! ma9 floor ( ! /ation is br\ght bel[ ! level ( ! :eel c5tres4 ,?is is mu* ! mo/ g5]al type ( con/ruction1 & 0 foll[$ 9 ! ,mass5a1 ,sault ,/e4 ,m>ie1 ,caon ,f]ry1 ,colgate1 ,electra1 ,santa ,ana1 & _m o!r well-kn[n wat]-p[] /ations4 ,if horizontal %afts are employ$ = :eels & g5]ators ) belt or rope connections betwe5 !m ! floor ( ! g5]ator room may be elevat$ a numb] ( feet above ! :eels4 ,?is diff]5ce ( elevation is usually provid$ = ei!r by upp] & l[] p>ts ( ! same room1 or by sep>ate rooms "o above ! o!r & a floor betwe5 !m4 ,a two-/ory con/ruction ( ?is latt] sort 0 frequ5tly adopt$ 9 ! old] wat]-p[] /ations1 & good examples ( x may be se5 9 connection ) ! electrical supply sy/em at ,burl+ton1 ,vt41 & ! ,indian ,or*>d /ation 9 ! ,spr+field1 ,mass41 sy/em4 ,v]tical :eel %afts make ! elevation ( ! ma9 or g5]ator floor ( a /ation indep5d5t ( t ( ! :eels1 & ?us give ! highe/ degree ( security aga9/ high wat]4 ,aft] ! v]tical :eel %aft rea*es ! g5]ator room1 x may be ge>$ to a horizontal %aft t has "o or m dynamos directly m\nt$ on x1 or drives dynamos ?r\gh belts or ropes4 ,belt-driv+ 9 ?is way1 f horizontal %afts connect$ by bevel ge>s ) v]tical :eel %afts1 is n uncommon 9 ! old] class ( wat]-p[] /ations4 ,g5]ators m\nt$ s+ly or 9 pairs on horizontal %afts t are driv5 by ge>+ on v]tical :eel %afts h be5 adopt$ at ! ,la*9e ,rapids & ,s\? ,b5d plants1 & x seems to (f] a desirable me?od ( connection 9 cases :]e v]tical :eels are necess>y & ! co/ ( g5]ators mu/ be kept at a l[ figure4 ,) ?is me?od ( driv+ ! g5]ators c be design$ = any economical spe$ & /ep be>+s avoid$4 ,illu/ration3 ,,fig4 #bf4--;,cross ,section ( ,comb9$ ,/eam- & ,wat]-p[] ,/ation at ,ri*mond1 ,va4 ,illu/ration3 ,,fig4 #bg4--;,cross ,section ( ,:eel ,h\se at ,bu*anan1 ,mi*4 ,! mo/ desirable me?od ( driv+ g5]ators ) v]tical :eels1 :]e ! exp5se is n too great1 is ! direct m\nt+ ( ea* g5]ator on ! upp] end ( a :eel %aft 7see cut74 ,?is me?od ( connection n only requires a special type ( g5]ator1 b may put s]i\s limits on its spe$4 ,9 g5]al1 ! p]iph]al spe$ ( a pressure turb9e %\ld be ab\t #ge p] c5t ( ! !oretical velocity ( wat] issu+ "u a head equal to t at :i* ! :eel op]ates1 9 ord] to give ! be/ effici5cy4 ,! rotative spe$s ( turb9es1 op]at+ "u any giv5 head1 %\ld ?us increase z _! capacities & diamet]s decrease4 ,because ( ^! pr9ciples x is ! common practice1 ) horizontal :eels1 to m\nt two or m on ea* %aft to :i* a g5]ator is direct-connect$ 9 ord] to obta9 a great] spe$ ( rotation ?an c\ld be obta9$ ) a s+le :eel ( _! comb9$ p[]4 ,?us1 at ,sault ,/e4 ,m>ie ! horizontal %aft on :i* ea* #djj-kil[att g5]ator is m\nt$ is driv5 at #ahj revolutions p] m9ute by f\r turb9es "u a head ( ab\t #bj feet4 ,at ,mass5a ! head ( wat] is #ej feet1 & ea* #e1jjj horse-p[] g5]ator is driv5 at #aej revolutions p] m9ute by six turb9es on a horizontal %aft4 ,v]tical turb9es are sometimes m\nt$ s+ly on _! %afts1 z 0 done 9 ! hydroelectric plant at ,oregon ,city on ! ,willamette ,riv]1 & ?is practice gives spe$s t are too l[ = direct-connect$ dynamos ( mod]ate co/1 unless ! head ( wat] is unusually great4 ,at ! ,oregon ,city plant ! head ( wat] is only #dj feet1 & yet a s+le #db-;in* turb9e 0 m\nt$ on ! v]tical %aft t drives ea* g5]ator4 ,illu/ration3 ,,fig4 #bh4--,longitud9al ,section ( ,bu*anan1 ,mi*41 ,p[]-h\se4 ,! mo/ notable examples ( direct-connect$ g5]ators & v]tical turb9es is t at ,niag>a ,falls1 :]e tw5ty-"o g5]ators ( #e1jjj horse-p[] ea* are m\nt$ at ! tops ( z _m v]tical :eel %afts 9 two ( ! f\r /ations4 ,ea* v]tical %aft 9 ! ,niag>a /ations is driv5 at #bej revolutions p] m9ute by a pair ( turb9es1 "o above ! o!r4 ,! maximum head betwe5 ! wat] 9 ! ,niag>a canal & t 9 ! tunnel :i* =ms ! tail-race is #afa feet4 ,on t5 %afts ! c5tres ( ! :eel cases are #acf feet bel[ ! level ( wat] 9 ! canal1 & no draft tubes are us$4 ,illu/ration3 ,,fig4 #bi4--,section ( ,p[]-h\se ,no4 #b at ,niag>a ,falls4 ,! elev5 pairs ( :eels at ! second ,niag>a p[]-h\se h _! c5tre l9e #abh4be feet bel[ ! canal level & a draft tube = ea* pair ( :eels ext5ds to a po9t bel[ ! tail-wat] level4 ,x is entirely practicable to use m ?an a s+le pair ( turb9es on ! same v]tical %aft1 z is %[n at ! ,hagneck /ation on ! ,jura1 9 ,switz]l&1 :]e ! head ( wat] is ab\t tw5ty-"o feet & f\r turb9es are m\nt$ on ea* v]tical %aft4 ,! comb9$ capacity ( ^! f\r :eels on ea* %aft is #a1ejj horse-p[] & its spe$ is #ajj revolutions p] m9ute4 ,at ! top ( ea* %aft an #h1jjj-volt g5]ator1 ) ext]nal1 revolv+ magnet frame1 is m\nt$4 ,! use ( f\r :eels p] v]tical %aft pres5ts no great difficulty & %\ld be resort$ to m frequ5tly 9 ! future4 ,illu/ration3 ,,fig4 #cj4--;,int]ior ( ,p[]-h\se1 ,bu*anan1 ,mi*4 ,= horizontal1 direct-connect$ turb9e :eels & g5]ators ! ne>ly uni=m practice is to locate ! g5]ators 9 a s+le r[ f "o end ( a /ation to ! o!r1 & ?is br+s ! turb9es into a p>allel r[4 ,on ?is plan ! %aft ( ea* connect$ g5]ator & its gr\p ( turb9es sets at "r angles to ! long] sides ( a /ation & approximately p>allel ) ! direction 9 :i* wat] fl[s to ! :eels4 ,! typical wat]-p[] /ation ) direct-connect$ units is ?us a r long1 n>r[ build+ into :i* wat] ent]s on "o side ?r\gh p5/ocks & leaves on ! o!r ?r\gh tail-races4 ,su* /ations usually set ) "o ( ! long] sides p>allel to ! riv] into :i* ! tail-wat] passes & betwe5 ?is riv] & ! canal or pipe l9e4 ,at ,mass5a ! electric /ation occupies ! position ( a dam betwe5 ! end ( ! p[] canal & ! ,grass ,riv]1 be+ ab\t #aej feet wide & #eej feet long4 ,canal wat] ent]+ ?is /ation passes ?r\gh its :eels to ! riv] "u a head ( ab\t #ej feet4 ,a simil> con/ruction 0 foll[$ at ,sault ,/e4 ,m>ie1 :]e ! p[]-/ation sep>ates ! end ( ! canal f ! ,/4 ,m>y's ,riv]4 ,?is /ation is #ajj feet wide1 #a1cfh feet long1 & is to conta9 #hj sets ( horizontal :eels1 ea* set be+ connect$ to its own g5]ator1 & ?r\gh ^! :eels ! canal wat] passes "u a head ( approximately #bj feet4 ,t5 g5]ators are plac$ 9 l9e at ! ,caon ,f]ry /ation :i* is #bbe by #ej feet inside1 & ea* g5]ator is driv5 by a pair ( horizontal :eels "u a head ( #cj feet4 ,?is /ation sets betwe5 a %ort canal & ! ,miss\ri ,riv]1 ne> "o end ( ! dam4 ,pass+ f wat]-heads ( less ?an #ej to ^? ( sev]al hundr$ or ev5 m ?an #a1jjj feet1 ! g5]al type ( /ation build+ rema9s ab\t ! same1 b !re is an important *ange 9 ! arrangem5t ( direct-connect$ :eels & g5]ators4 ,) ^! high heads ( wat]1 :eels ( ! impulse type1 to :i* ! wat] is suppli$ 9 ! =m ( jets f nozzles1 are employ$4 ,^! jets pass to ! :eels 9 planes at "r angles to _! %afts1 in/ead ( fl[+ 9 l9es p>allel to ^! %afts l wat] to pressure turb9es4 ,! %afts ( impulse :eels & _! direct-connect$ g5]ators are consequ5tly arrang$ p>allel ) ! long] in/ead ( ! %ort] sides ( _! /ations4 ,?is plan results 9 long1 n>r[ /ations ) wat] ent]+ at "o & leav+ at ! o!r ( ! long] sides1 j z 9 ! case ( direct-connect$ turb9es "u mod]ate heads4 ,/ations ) direct-connect$ impulse :eels are ev5 long] = a giv5 numb] & capacity ( units ?an are /ations ) pressure turb9es4 ,colgate p[]-h\se1 on ! ,nor? ,yuba ,riv]1 conta9s sev5 g5]ators1 ea* direct-connect$ to an impulse :eel & %afts all p>allel to its long] sides4 ,?is /ation is #bge feet long by #dj feet wide1 & ! wat] :i* ent]s "o side by five iron pipes1 #cj in*es ea* 9 diamet]1 "u a head ( ab\t #gjj feet1 is dis*>g$ f ! o!r side into ! riv]4 ,illu/ration3 ,,fig4 #ca4--,plan ( ,g5]at+ ,/ation ne> ,c$> ,lake = ,city ( ,seattle1 ,wa%4 ,illu/ration3 ,,fig4 #cb4--;,f\ndation ( ,p[]-/ation at ,spi] ,falls4 ,illu/ration3 ,,fig4 #cc4--,plan ( ,p[]-/ation at ,great ,falls4 ,at ,electra /ation on ! ,mokelumne ,riv] five pairs ( impulse :eels are direct-connect$ to five g5]ators1 ea* unit hav+ its %aft diagonal ) ! walls ( ! build+1 & pipes deliv] wat] to ! :eels "u a head ( #a1dej feet4 ,! gr\nd plan ( ! g5]ator room at ?is plant is #dj by #bjh feet4 ,! p[]-/ation on ,santa ,ana ,riv]1 :5ce en]gy is transmitt$ #hc miles to ,los ,angeles1 measures #abg feet long & #cf feet wide inside1 & conta9s f\r g5]at+ units 9 l9e1 ea* ( :i* consi/s ( a direct-connect$ dynamo & impulse :eel1 ) %afts p>allel to ! long] sides ( ! /ation4 ,jets driv+ ! :eels 9 ?is /ation are deliv]$ "u a head ( #gbh feet m9us ! loss by friction 9 a p5/ock #b1baj feet long4 ,illu/ration3 ,,fig4 #cd4--,p[]-h\se at ,r$ ,bridge on ,*icopee ,riv]4 ,bo? ( ! fir/ ,niag>a plants1 ) v]tical :eels f> bel[ ! /ations 9 ! pits1 are long & n>r[ & h _! g5]ators 9 a s+le r[4 ,! lat] ( ^! two /ations has a gr\nd area ( approximately #gb by #dif feet outside1 & conta9s elev5 g5]ators all 9 l9e4 ,f ^! examples x may be se5 t ! prevail+ type ( electric wat]-p[] /ation1 :e!r design$ = horizontal or v]tical :eels ( ei!r ! pressure or impulse type1 is wide en\gh = only a s+le r[ ( g5]ators & :eels1 & has suffici5t l5g? to accommodate ! requir$ numb] ( units4 ,a few mod]n /ations t dep>t f ?is g5]al plan w be f\nd1 z t at ,great ,falls1 on ! ,presumpscot ,riv]1 :5ce electrical supply = ,portl&1 ,me41 is drawn4 ,?is /ation sets ab\t =ty feet 9 front ( ! =ebay end ( ! dam1 & two p5/ocks ent] ! re> wall1 :ile ! o!r two ent] "o ea* ?r\gh two ( ! rema9+ opposite sides4 ,( ! f\r g5]ators1 ) _! direct-connect$ :eels1 two are arrang$ ) p>allel %afts1 :ile ! o!r two h _! %afts 9 l9e & at "r angles to ! l9es ( ! =m] two4 ,! /ation conta9+ ^! g5]at+ sets has a floor area ( #ee by #fg4e feet4 ,illu/ration3 ,,fig4 #ce4--,plan & ,elevation ( ,r$ ,bridge ,/ation on ! ,*icopee ,riv]4 ,mod]n electric /ations driv5 by wat]-p[] are usually b "o /ory 9 height & are cle> inside f floor to ro(1 save = cranes & ro( trusses4 ,?is con/ruction may be se5 9 ! ,niag>a1 ,spi] ,falls1 ,caon ,f]ry1 ,colgate1 ,electra1 ,santa ,ana ,riv] & _m o!r notable plants4 ,9 spite ( ?is "o-/ory /yle ( con/ruction1 ! electric /ations rea* fair elevations because ( ! necessity = head room to op]ate cranes 9 plac+ & remov+ g5]ators4 ,at ,g>v9's ,falls1 on ! ,m]rimac ,riv]1 ! electric /ation conta9s g5]ators ( #fej kil[atts ea* & ! di/ance f floor to ! l[] cords ( ro( trusses is #bg feet4 ,9 ! /ation at ,r$ ,bridge1 on ! ,*icopee ,riv]1 :]e g5]ators are ( #a1jjj kil[atts capacity ea*1 ! di/ance betwe5 floor & ! "u side ( ro( beams is #cj4ff feet4 ,betwe5 ! floor & ro( trusses at ! ,bir*em ,b5d /ation1 on ! riv] la/ nam$1 ! di/ance is #bf4be feet1 b ea* g5]ator is rat$ at only #djj kil[atts4 ,9 ! ,caon ,f]ry plant1 ) its g5]ators ( #gej kil[atts ea*1 ! di/ance f floor to ro( trusses is #bh feet4 ,at ! plant on ,santa ,ana ,riv]1 ! #gej-kil[att g5]ators1 be+ connect$ to impulse-:eels1 op]ate at #cjj revolutions p] m9ute1 h relatively small diamet]s & are m\nt$ ov] pits 9 ! floor s t _! %aft c5tres are only ab\t two feet above x4 ,by ^! means ! di/ance f floor to ro( trusses 0 r$uc$ to #ah4be feet4 ,all ^! examples ( elevations betwe5 floors & ro( supports are = /ations ) direct-connect$ g5]ators & horizontal :eels4 ,9 ! new ,niag>a /ation1 :]e g5]ators ( #c1gej kil[atts ea* are m\nt$ on v]tical :eel %afts t rise f ! floor1 ! di/ance betwe5 ! floor & ro( trusses is #ci4e feet4 ,electric /ations driv5 by wat]-p[] are n[ con/ruct$ almo/ entirely ( mat]ials t w n burn--t is1 /one1 brick1 tile1 concrete1 cem5t1 iron1 & /eel4 ,/one masonry laid ) cem5t mort> or concrete masonry is v g5]ally employ$ = all ^? p>ts ( ! f\ndations t come 9 contact ) ! tail-wat]4 ,= sub-f\ndations b$rock is v desirable1 b :]e ?is _c be rea*$ piles are driv5 closely & _! tops cov]$ ) sev]al feet ( cem5t concrete z a b$d+ = ! /one f\ndation4 ,:]e /one is pl5ty or bricks h>d to obta91 ! entire walls ( a wat]-p[] /ation are frequ5tly laid entirely ) /one 9 concrete mort>4 ,if bricks c readily be _h !y are m commonly us$ ?an /one = /ation walls above ! f\ndations4 ,concrete =m$ into a monoli?ic mass is a favorite type ( con/ruction = ! f\ndations1 walls & floors ( wat]-p[] plants 9 ,s\!rn ,cali=nia4 ,cem5t & concrete are mu* us$ = /ation floors 9 all p>ts ( ! c\ntry1 & ^! floors are support$ by masonry ar*es 9 cases :]e ! tail-wat] fl[s und]nea? ! /ation aft] leav+ ! :eels4 ,/ation ro(s are usually support$ by /eel trusses or ,i-beams1 & slate & iron are favorite ro( mat]ials4 ,) iron ro(-plates an int]ior l9+ ( wood1 asbe/os1 or "s o!r poor conductor ( heat is mu* us$ to prev5t ! cond5sation ( wat] on ! "u side ( ! ro( 9 cold wea!r4 ,walls ( wat]-p[] /ations are usually giv5 suffici5t ?ickness ( masonry to support all loads t come ^u !m )\t ! aid ( /eel columns4 ,9 "s cases :]e cranes d n ext5d entirely across _! /ations1 "o end ( ea* crane is support$ by "o ( ! /ation walls & ! o!r end by a r[ ( iron or /eel columns ris+ f ! floor4 ,:]e ! g5]ator-room ( a /ation has its floor level bel[ high-wat] m>k especial c>e %\ld be tak5 to make ! walls wat]-pro( to an elevation above ?is m>k4 ,z ! travell+-crane & ! loads :i* x c>ries 9 erect+ :eels & g5]ators =m a l>ge "p ( ! weight on ! /ation walls1 ^! walls are (t5 r$uc$ z mu* z "o-half 9 ?ickness at ! level ( ! crane1 ?us =m+ b5*es on :i* ! ends ( ! cranes re/4 ,illu/ration3 ,,fig4 #cf4--,/eel ,p5/ocks at ,*amblay ,p[]-h\se4 ,! ,g>v9's ,falls /ation1 on ! ,m]rimac ,riv]1 re/s on ar*es ( /one masonry ?r\gh :i* ! tail-wat] passes1 & ! brick walls are wat]-pro($ to an elevation eight feet above ! floor4 ,at tw5ty feet above ! floor ! tw5ty-f\r-in* brick walls on ! two long] sides are r$uc$ to eight in*es 9 ?ickness1 ?us =m+ b5*es ea* sixte5 in*es wide on :i* ! crane travels4 ,ar*es ( /one masonry support ! tw5ty-f\r-in* brick walls ( ! /ation at ,r$ ,bridge1 on ! ,*icopee ,riv]1 & ^! walls on ! two long] sides decrease 9 ?ickness to twelve in*es at an elevation ( tw5ty-"o feet above ! floor1 ?us =m+ b5*es twelve in*es wide = ! ends ( ! crane4 ,"o concrete wall ( ! ,santa ,ana /ation is #b4e feet ?ick to a di/ance ( #ac4e feet above ! floor1 & !n %r9ks to a ?ickness ( #a4e feet1 correspond+ to t ( ! opposite wall1 ?us =m+ a b5* twelve in*es wide = "o end ( ! crane4 ,! o!r end ( ! crane 9 ?is case is support$ by an ,i-beam on a r[ ( iron columns4 ,x is n uncommon to locate horizontal turb9es 9 a room sep>ate f t occupi$ by ! g5]ators to :i* !y are direct-connect$1 9 ord] to protect ! latt] f wat] 9 ! ev5t ( a break 9 p5/ocks or :eel cases4 ,9 cases ( ?is sort ! %afts connect+ :eels & g5]ators pass ?r\gh ! wall betwe5 !m4 ,! horizontal turb9es may be locat$ at ! bottom ( a canal ^: wat] presses aga9/ ! wall ?r\gh :i* ! :eel %afts pass1 or !y may be conta9$ 9 iron cases at ! ends ( p5/ocks4 ,9 ?is latt] case an ext5sion ( ! /ation is (t5 provid$ = a :eel room to conta9 ^! cases4 ,su* :eel rooms are long1 n>r[1 l[-ro($ & p>allel to ! g5]ator rooms ( _! /ations4 ,! floors ( ^! :eel rooms are at ne>ly ! same levels z ! floors ( g5]ator rooms1 b elevations ( _! ro(s above ! floors are mu* less ?an l elevations 9 ! ma9 p>ts ( ! /ations4 ,! ,g>v9's ,falls1 ,r$ ,bridge1 & ,apple ,riv] /ations h :eel rooms ( ! type j describ$4 ,) impulse-:eels to :i* wat] passes 9 planes at "r angles to _! %afts x is desirable1 9 ord] to avoid *anges 9 ! direction ( wat] pipes1 t direct-connect$ :eels & g5]ators occupy ! same room1 & ?is is ! arrangem5t at ! ,colgate1 ,electra1 ,santa ,ana1 ,mill ,creek1 & _m o!r p[]-h\ses us+ su* equipm5ts4 ,! area ( a :eel room may frequ5tly be r$uc$ at /ations op]at+ direct-connect$ horizontal-pressure turb9es "u l[ heads by plac+ ! :eels at ! bottom ( ! canal :i* has "o side ( ! /ation or g5]ator room = a reta9+ wall4 ,?is plan 0 adopt$ at ! ,bir*em ,b5d plant ) a head ( f\rte5 feet1 & at ! ,sault ,/e4 ,m>ie /ation :]e ! head ( wat] is ab\t tw5ty feet4 ,v]tical :eels direct-connect$ to g5]ators mu/ be directly und]nea? ! ma9 room ( _! /ation1 & may be 9 a canal ov] :i* ! /ation is built1 9 a :eel room t =ms its l[] "p1 or 9 a :eel pit & suppli$ ) wat] ?r\gh p5/ocks1 z at ! ,niag>a ,falls plants4 ,/ep-up trans=m]s develop+ v high voltages are n an elem5t ( safety 9 a g5]ator room1 & ! bett] practice is to locate !m 9 a sep>ate ap>tm5t by !mselves1 if n 9 a sep>ate build+4 ,= ! ,niag>a ,falls plant1 ! trans=m]s t deliv] ?ree-phase curr5t at #bb1jjj volts are locat$ 9 a build+ across ! canal f ! g5]at+ plant4 ,at ,caon ,f]ry ! trans=m]s op]at+ at #ej1jjj volts1 ?ree-phase1 are locat$ 9 a /eel & iron addition to ! p[]-h\se4 ,trans=m]s at ,electra /ation1 :i* are int5d$ to "w ultimately at #fj1jjj volts1 are locat$ 9 an ext5sion ( ! ma9 build+ & are sep>at$ f ! g5]ator-room by a wall4 ,at ! ,santa ,ana plant ! #cc1jjj-volt trans=m]s are gr\p$ 9 "o corn] ( ! g5]ator room1 b no p>tition sep>ates _! space f ! rema9d] ( ! room4 ,9 ! ,colgate plant ! trans=m]s1 work+ at #dj1jjj volts1 are spac$ along "o ( ! long] sides ( ! /ation opposite to & only a few feet f ! r[ ( g5]ators4 ,"o end ( ! ma9 room 9 ! ,apple ,riv] plant is devot$ exclusively to ! #be1jjj-volt trans=m]s1 & !re is a di/ance ( ab\t tw5ty-sev5 feet betwe5 !m & ! ne>e/ g5]ator4 ,! highe/ degree ( safety = trans=m]s at ^! great voltages seems to require t !y be locat$ 9 a sep>ate room :]e ! floor1 walls1 & ro( are made entirely ( incombu/ible mat]ial4 ,illu/ration3 ,,fig4 #cg4--,"o ( ! ,turb9e ,:eels at ,spi] ,falls on ! ,hudson ,riv]4 ,wat] suppli$ to horizontal turb9e :eels "u mod]ate heads usually ent]s ! /ation by p5/ocks on "o side & leaves x by ! tail-race on ! o!r1 b ?is is n true 9 e case4 ,at ! ,bir*em ,b5d plant1 ! canal 9 :i* ! :eels are locat$ be+ betwe5 ! /ation & ! riv]1 wat] nev] ent]s or passes "u ! /ation1 :i* has a cont9u\s f\ndation4 ,s aga9 at ! ,apple ,riv] plant ! s+le supply pipe1 twelve feet 9 diamet] & deliv]+ wat] "u a head ( eighty-two feet1 lies p>allel ) ! great] l5g? ( ! /ation & betwe5 x & ! riv]4 ,%ort p5/ocks pass f ?is supply pipe into ! :eel section ( ! p[]-h\se1 & ! wat] aft] pass+ ?r\gh ! :eels fl[s out to ! riv] betwe5 ! masonry pi]s t support ! twelve-foot pipe4 ,! g5]ator section ( ?is /ation has ?us no wat] fl[+ "u x4 ,an int]e/+ di/9ction may be not$ betwe5 ! conditions z to ! tail-wat] ab\t ! f\ndations ( /ations work+ "u l[ & ^? "u great wat] heads4 ,9 cases ( ! =m] sort ! volumes ( wat] are relatively great & ! f\ndations ( /ations are usually subm]g$1 & mu* r$uc$ 9 area to make room = ! tail-races4 ,?us1 ! f\ndations ( ! /ation at ,r$ ,bridge1 :]e !re is #di feet head1 h ne>ly all ( _! foot+s "u wat]1 & ( a total l5g? ( #ade feet at ! top ( ^! f\ndations ! six tail-races und]nea? cut out #ib feet4 ,^! tail-races ext5d und]nea? bo? ! :eel & g5]ator rooms4 ,:]e p[] is d]iv$ f wat] deliv]$ "u great head f pipe nozzles to impulse-:eels1 /ations are usually well above ! wat] levels ( /reams into :i* !y dis*>ge1 & passages = tail-wat] und]nea? ! /ation %r9k to small tunnels ?r\gh _! f\ndations4 ,sev5 ( ^! tunnels h a total wid? ( less ?an #be feet at ! ,santa ,ana ,riv] /ation1 :i* is #abg feet long1 & :]e ! head ( wat] is #gbh feet4 ,at ! ,colgate plant1 ) its head ( #gjj feet1 ! wat]1 at times ( light load1 in/ead ( fl[+ out ( its passages und]nea? ! /ation1 %oots f ! pipe nozzles cle> across ! ,nor? ,yuba ,riv] on ! bank ( :i* ! /ation /&s4 ,illu/ration3 ,,fig4 #ch4--,p[] ,plant ( ,ludl[ ,manufactur+ ,company4 ,9 a comp>ison ( floor areas p] kil[att ( ma9 g5]ator capacities 9 electric /ations us+ wat]- & ^? us+ /eam-p[]1 ! matt] ( space = trans=m]s may be entirely omitt$1 because ! ext5t ( ?is space is indep5d5t ( ! type or location ( wat]-:eels1 or ! diff]5ce ( wat] & /eam z motive p[]s4 ,:]e wat]-:eels & _! connect$ g5]ators occupy sep>ate rooms1 z is (t5 ! case ) turb9es "u l[ pressures1 ! :eel room has a little less l5g?1 & is g5]ally n>r[] ?an ! g5]ator room4 ,?us1 at ! ,r$ ,bridge /ation ! g5]ator room is #ada feet long & ! :eel room ab\t #abg feet1 :ile ! =m] is #cc4cc feet & ! latt] #bd feet wide4 ,s aga9 at ,apple ,riv] ,falls ! g5]ator room is #adj by #cj feet & ! :eel room #ajf by #bb feet1 ! g5]ator room 9 ?is case conta9+ also trans=m]s4 ,x foll[s t if :eels c be locat$ outside ( ! /ation1 z 9 a canal1 q a r$uction 9 its total floor area c be made1 :i* may easily range f #bj to #dj p] c5t4 ,! kil[att capacity p] squ>e foot ( floor area 9 bo? :eel & g5]ator rooms comb9$ t5ds to increase ) ! individual capacity ( ! g5]at+ units4 ,g5]ators on v]tical %afts seem to require ab\t z mu* floor space p] unit ( capacity z d g5]ators on horizontal %afts4 ,9 ! ,r$ ,bridge /ation ! total capacity is #d1hjj kil[atts ( ma9 g5]ators 9 six horizontal units1 & ! area ( ! g5]ator room alone is #j4if squ>e foot p] kil[att ( ?is capacity4 ,! second /ation ) v]tical units at ,niag>a ,falls has a capacity ( #da1bej kil[atts 9 elev5 g5]ators on v]tical %afts1 & its floor area am\nts to #j4hf squ>e foot p] kil[att2 n>r[ impulse-:eels ( l>ge diamet] t5d to economy ( floor space1 z 9 ,electra /ation1 :]e ! room conta9+ :eels & g5]ators has an area ( only #j4hc squ>e foot p] unit ( its #aj1jjj kil[atts capacity4 ,at ! ,colgate plant1 :]e ! total rat+ ( g5]ators is #aa1bej kil[atts1 ! floor area "u :eels & g5]ators is almo/ exactly "o squ>e foot p] kil[att4 ,! ,santa ,ana /ation1 ) a total capacity ( #c1jjj kil[atts1 has #a4eb squ>e feet ( floor area = ea* unit ( capacity4 ,?is la/ figure may be comp>$ ) ! #a4gb squ>e feet p] kil[att ( g5]ator rat+ = ! #d1hjj-kil[att /ation at ,r$ ,bridge & ! #a4ge squ>e feet p] unit ( capacity 9 ! #hjj-kil[att plant at ,bir*em ,b5d4 ,illu/ration3 ,,fig4 #ci4--,p[]-h\se on ,payette ,riv]1 ,idaho4 ,all types ( wat]-p[] /ations ) direct-connect$ :eels & g5]ators h mu* small] floor areas p] unit capacity ?an d /eam-p[] /ations ) direct-connect$ horizontal units4 ,?us1 ! mod]n /eam-driv5 /ation at ,portsm\?1 ,n4 ,h41 has a plan area 9 eng9e- & boil]-rooms ( #af1hga squ>e feet1 & its total capacity 9 f\r direct-connect$ units is #d1djj kil[atts1 s t ! area am\nts to #c4hb squ>e feet p] kil[att rat+ ( its g5]ators4 ,( ?is area ab\t #df p] c5t is 9 ! boil]-room4 ,,floor ,,dim5sions ,,= ,,direct-,,connect$1 ,,horizontal ,,wat]-,,:eels ,,& ,,g5]ators ,,at ,,electric ,,/ations4 ---------------------------------------- ------------------- ,numb] ,total ,/ation4 ,feet ,long4 ,feet ,wide4 ( ,kil[att ,g5]ators4,capacity4 ---------------------------------------- ------------------- ,a,niag>a1 ,no4 #b #dif #gb #aa #da1bej ,sault ,/e4 ,m>ie #a1cfh #ajj #hj #cb1jjj ,colgate #bge #dj #g #aa1bej ,electra #bjh #dj #e #aj1jjj ,caon ,f]ry #bbe #ej #aj #g1ejj ,r$ ,bridge #ada #eg #f #d1hjj ,apple ,riv] #adj #cj #d #c1jjj #ajf #bb ,santa ,ana ,riv] #abg #cf #d #c1jjj ,great ,falls #fg4e #ee #d #b1jjj ,g>v9's ,falls #fb #cj #b #a1cjj #ej #bc ,bir*em ,b5d #ef4f #bf4g #b #hjj ,portsm\? #ad4d #aai4ff 7/eam-driv57inside1 b m9us #cfj #e #d1djj squ>e feet4 ---------------------------------------- ------------------- ,a ,v]tical :eel %afts4 ,"s ( ^! dim5sions apply to ! inside & "s to ! outside ( /ations4 ,"s small projections are n includ$4 ,,*apt] ,,ix4 ,,alt]nators ,,= ,,electrical ,,transmission4 ,dynamos 9 ! g5]at+ /ation ( an electric transmission sy/em %\ld be s num]\s t if "o ( !m is disabl$ ! o!rs c c>ry ! maximum load4 ,if only two g5]ators are in/all$1 x is ?us desirable t ea* be l>ge en\gh to supply ! entire output1 s t ! dynamo capacity exce$s ! greate/ dem& on ! /ation by #ajj p] c5t4 ,to avoid s great excess ( dynamo capacity x is common practice to in/all m ?an two g5]ators4 ,o!r consid]ations also t5d to increase ! numb] ( dynamos 9 ! g5]at+ /ation ( a transmission sy/em4 ,?us "o transmission l9e may be devot$ exclusively to light+1 ano!r to /ation>y motors1 & a ?ird to electric railway s]vice2 & x may be desirable t ea* l9e be suppli$ by an indep5d5t dynamo to avoid any effect ( fluctuations ( railway or motor load on ! light+ sy/em4 ,at ! g5]at+ /ation ( ! transmission sy/em t supplies electric light & p[] 9 ,portl&1 ,me41 ! idea ( indep5d5t units has be5 c>ri$ out ) f\r #ejj-kil[att dynamos1 ea* driv5 by a pair ( :eels f$ ) wat] ?r\gh a sep>ate p5/ock f ! dam4 ,ea* ( ^! dynamos op]ates "o ( ! f\r indep5d5t transmission circuits4 ,:]e a numb] ( wat]-p[] /ations fe$ into a s+le sub-/ation ! requirem5t t ea* g5]at+ /ation h its capacity divid$ up among q a numb] ( dynamos may n exi/1 s9ce "o /ation may be entirely %ut d[n = repairs & ! load c>ri$ meantime by ! o!r /ations4 ,a good illu/ration ( ?is po9t may be se5 at ,man*e/]1 :]e a s+le sub-/ation receives en]gy transmitt$ f f\r wat]-p[] plants4 ,at "o ( ^! plants ! entire capacity ( #a1bjj kil[atts is 9 a s+le g5]ator4 ,! =ego+ consid]ations z to ! numb] ( dynamos apply ) equal =ce to bo? /eam- & wat]-driv5 /ations1 b o!r factors t5d to increase ! numb] ( dynamos 9 wat]-p[] plants :]e ! head ( wat] is comp>atively small4 ,?is t5d5cy is due to ! fact t ! p]iph]al spe$s ( pressure turb9e wat]-:eels %\ld be ab\t tw5ty-five p] c5t less ?an ! velocity at :i* wat] w\ld issue f an op5+ "u ! head ( wat] at :i* ^! :eels op]ate 9 ord] to secure high effici5cy4 ,?is velocity ( wat] & !re=e ! p]iph]al spe$ ( pressure turb9e :eels v>ies ) ! squ>e root ( ! head ( wat]4 ,illu/ration3 ,,fig4 #dj4--;,g5]ators at ,sault ,/e4 ,m>ie ,p[] ,plant4 ,s9ce ! p]iph]al spe$ ( turb9es is ?us det]m9$ by ! heads ( wat] "u :i* !y op]ate1 & s9ce ! diamet]s ( turb9es mu/ increase ) _! capacities1 ! rate ( revolution = pressure turb9es "u any giv5 head decreases z ! p[] goes up4 ,= ?is reason x is (t5 desirable to use a l>g] numb] ( dynamos 9 a wat]-p[] plant ?an w\ld o!rwise be requir$ 9 ord] to avoid v l[ spe$s ( revolution on ! direct-connection to ! turb9es4 ,a notable illu/ration ( ?is practice exi/s 9 ! great wat]-p[] plant ( ! ,mi*igan-,lake ,sup]ior ,p[] ,company1 at ,sault ,/e4 ,m>ie1 ,mi*41 :]e a g5]at+ capacity ( #cb1jjj kil[atts is divid$ up betwe5 #hj dynamos ( #djj kil[atts ea*4 ,! head ( wat] available at ! pressure turb9es 9 ?is plant is ab\t #af feet1 & _! spe$ is #ahj revolutions p] m9ute4 ,9 ord] to obta9 ev5 ?is mod]ate spe$ "u ! head ( #af feet x 0 necess>y to select turb9es ( only #adj horse-p[] ea*4 ,f\r ( ^! turb9es are m\nt$ on ea* %aft t drives a #djj-kil[att dynamo1 direct-connect$1 s t !re are #cbj :eels 9 all4 ,_h a small] numb] ( :eels be5 employ$ to yield ! total p[] _! spe$ & t ( direct-connect$ dynamos mu/ h be5 less ?an #ahj revolutions p] m9ute4 ,z ! co/ ( dynamos increases ) v l[ spe$s x is (t5 *eap] to in/all a l>g] numb] ( dynamos at a high] spe$ ?an a small] numb] at a l[] spe$ = a giv5 total capacity4 ,! use ( a l>g] numb] ( units ?an w\ld o!rwise be necess>y 9 ord] to avoid a v l[ spe$ is fur!r illu/rat$ by ! #g1ejj-kil[att plant ( ! ,miss\ri ,riv] ,p[] ,company1 at ,caon ,f]ry1 ,mont4 ,?is capacity is made up ( t5 g5]ators1 ea* rat$ at #gej kil[atts & direct-connect$ to a pair ( pressure turb9e :eels op]at+ at #aeg revolutions p] m9ute1 "u a head ( ab\t #cb feet4 ,"u comp>atively high heads ( wat] pressure turb9es op]ate at spe$s t are ample = direct-connection to ev5 ! l>ge/ dynamos4 ,illu/ration3 ,,fig4 #da4--;,int]ior ( ,p[]-h\se ,no4 #b1 ,niag>a ,falls4 ,?us 9 ! ,niag>a ,falls plant1 :]e ! head ( wat] is #acf feet1 ea* pair ( turb9es drives a direct-connect$ dynamo ( #c1gej kil[atts at #bej revolutions p] m9ute4 ,9 ! r>e case :]e ! p[] to be develop$ is s great t ! numb] ( g5]ators necess>y to give security & reliability to ! s]vice leaves ea* g5]ator ) a capacity l>g] ?an is desirable = /ructural reasons1 ! numb] mu/ be increas$ simply to r$uce ! size ( ea* g5]ator4 ,su* a /ate ( facts exi/$ at ,niag>a ,falls1 :]e ! fir/ /ation conta9s t5 dynamos ( #c1gej kil[atts ea*1 & ! second /ation conta9s elev5 units ( l capacity4 ,9 ! great] numb] ( transmission sy/ems ! g5]ators are direct-connect$ to ei!r /eam-eng9es or wat]-:eels1 & _! spe$s ( rotation are l>gely det]m9$ by ! requirem5ts ( ^! prime mov]s4 ,/eam-eng9es c be design$ ) "s reg>d to ! desirable spe$s = direct-connection to dynamos1 b wat]-:eels are less flexible 9 ?is p>ticul>4 ,ea* type ( :eel has its p]iph]al spe$ ma9ly det]m9$ by ! head ( wat] "u :i* x may be requir$ to op]ate1 & v>iation f ?is spe$ means s]i\s loss ( effici5cy4 ,illu/ration3 ,,fig4 #db4--aj1jjj ,h4 ,p4 #ab1jjj ,volt ,g5]ator 9 ,canadian ,p[]-h\se at ,niag>a ,falls4 ,"u heads ( mu* m ?an #ajj feet pressure turb9es op]ate at r high spe$s 9 all except v l>ge sizes4 ,x is mu* ! m common to see wat]-:eels at a l[] spe$ belt$ to dynamos at a high] spe$2 b 9 "s in/ances1 z at ! light+ plant ( ,spokane1 ,wa%41 :eels ( a high] spe$ are belt$ to dynamos ( a l[] spe$4 ,ano!r plan by :i* mod]ate dynamo spe$s are obta9$ ) wat]-:eels "u r high heads m\nts a dynamo at ea* end ( ! %aft ( a l>ge turb9e or pair ( turb9es4 ,?is plan is foll[$ at ! plant ( ! ,royal ,alum9um ,company1 ,%aw9igan ,falls1 ,quebec1 :]e !re are two pairs ( horizontal turb9e :eels1 ea* pair develop+ #c1bjj horse-p[] "u a head ( #abe feet1 & driv+ a dynamo direct-c\pl$ on ea* end ( its %aft4 ,:]e v]tical :eels are employ$ x is sometimes m desirable to drive "s /&>d type ( dynamo ) horizontal %aft by means ( bevel ge>s ?an to design a special dynamo to m\nt directly on ! v]tical %aft4 ,?is latt] plan is w>rant$ 9 v l>ge "w l t at two ( ! ,niag>a ,falls g5]at+ /ations1 :]e ! tw5ty-"o #c1gej-kil[att dynamos are direct-connect$1 ea* on ! v]tical %aft ( a turb9e4 ,?is type ( connection is n "o t w be frequ5tly foll[$1 b at "o o!r po9t--,portl&1 ,ore4--ea* dynamo is m\nt$ directly on ! %aft ( its v]tical turb9e :eel4 ,:]e wat]-:eels mu/ op]ate "u heads ( sev]al hundr$ feet1 x is usually necess>y to ab&on pressure turb9es & to adopt "o ( ! types ( impulse-:eels4 ,9 ?is class ( :eels ! p]iph]al spe$ ( highe/ effici5cy is only "o-half ! sp\t+ velocity ( ! wat] "u any p>ticul> head4 ,?is gives ! impulse-:eels ab\t two-?irds ! p]iph]al spe$ ( pressure turb9es ( equal diamet] & consequ5tly ab\t two-?irds z _m revolutions p] m9ute4 ,b z ! wat] may be appli$ at "o or m po9ts on ! circumf]5ce ( an impulse-:eel1 z desir$1 su* :eels may h mu* great] diamet]s ?an pressure turb9es = equal p[] "u a giv5 head4 ,illu/ration3 ,,fig4 #dc4--;,g5]ators 9 ,p[]-/ation at ,me*anicsville on ! ,hudson ,riv]4 ,illu/ration3 ,,fig4 #dd4--;,g5]ators at ,*amblay1 ,quebec1 ,p[]-h\se4 ,^! prop]ties ( l[ p]iph]al spe$1 z to head & great diamet]1 z to p[] develop$1 fit impulse-:eels = direct-connection to dynamos :]e great heads ( wat] mu/ be employ$1 & !y are g5]ally us$ 9 su* cases4 ,?is is p>ticul>ly true = ! ,pacific coa/1 :]e wat]-p[]s dep5d m on great heads ?an on l>ge volumes4 ,9 ! g5]at+ plant ( ! ,bay ,c\nties' ,p[] ,company1 at ,colgate1 ,cal41 ! dynamos are direct-connect$ to impulse-:eels t op]ate "u a head ( #gjj feet4 ,! ?ree #b1bej-kil[att dynamos 9 ?is plant are ea* m\nt$ on a :eel %aft op]at+ at #bhe revolutions p] m9ute1 & ea* ( ! f\r #a1abe-kil[att dynamos is direct-driv5 by an impulse-:eel at #djj revolutions p] m9ute4 ,at ! ,electra1 ,cal41 plant ( ! ,/&>d ,electric ,company ! impulse-:eels op]ate at #bdj revolutions p] m9ute "u a head ( #a1dej feet4 ,ea* ( ! five pairs ( ^! :eels drives a #b1jjj-kil[att g5]ator1 direct-connect$4 ,z ! head ( wat] at ^! :eels is #a1dej feet1 its sp\t+ velocity is ab\t #cjj feet p] second1 or #ah1jjj feet p] m9ute4 ,ea* :eel is elev5 feet 9 diamet]1 s t a spe$ ( #bdj revolutions p] m9ute gives ! p]iph]y a little less ?an #i1jjj feet p] m9ute1 or ab\t "o-half ( ! sp\t+ velocity ( ! wat]4 ,^! two great plants are excell5t illu/rations ( ! way 9 :i* impulse-:eels1 "u great heads1 may be giv5 spe$s t are suitable = direct-connect$ dynamos4 ,illu/ration3 ,,fig4 #ea;a4 ,plan & ,elevation ( ,wat] ,:eels & ,g5]ators at ,p[] ,/ation on ,burr>d ,inlet1 ne> ,vanc\v]1 ,b4 ,c4 ,?ree types ( alt]nators1 ! revolv+ armature1 ! revolv+ magnet1 & ! inductor1 are us$ 9 ! g5]at+ plants ( electric transmission sy/ems4 ,revolv+ armatures are us$ 9 ! dynamos ( comp>atively few transmission sy/ems & h>dly at all 9 ^? ( rec5t date4 ,! prevail+ type ( alt]nator = transmission "w is t ) int]nal revolv+ magnets & ext]nal /ation>y armature4 ,?is type is employ$ 9 ! great wat]-p[] plants at ,caon ,f]ry1 ,mont42 ,sault ,/e4 ,m>ie1 ,mi*41 & = all ( ! g5]ators in/all$ 9 ! lat] ,niag>a ,falls plants4 ,= ! sixte5 e>li] v]tical g5]ators at ,niag>a ,falls ! revolv+ magnets are ext]nal to ! /ation>y armatures1 b ?is con/ruction has ! disadvantage ( high fir/ co/ & inaccessibility ( ! int]nal armature1 & is n likely to be (t5 adopt$ else:]e4 ,illu/ration3 ,,fig4 #df4--;,elevations ( ,wat]-:eels & ,g5]ators at ,p[]-/ation on ,burr>d ,inlet1 ne> ,vanc\v]1 ,b4 ,c4 ,inductor alt]nators are ^? 9 :i* bo? ! armature & magnet coils are /ation>y & only a suitable /ructure ( iron revolves2 !y are employ$ 9 a comp>atively small numb] ( transmission sy/ems1 b ?is numb] includes "s ( ! l>ge/ plants4 ,! sev5 alt]nators 9 ! ,colgate1 ,cal41 plant aggregat+ #aa1bej kil[atts capacity1 & ! five alt]nators 9 ! plant at ,electra 9 ! same ,/ate1 ) a capacity ( #aj1jjj kil[atts1 are all ( ! inductor type4 ,z m commonly con/ruct$ ! magnet w9d+ ( ! inductor alt]nator consi/s ( only "o or two v l>ge coils1 :i* are 9 "s cases z mu* z t5 feet 9 diamet]4 ,! repair ( ^! l>ge magnet coils seems to pres5t a m s]i\s problem1 9 case ( accid5t1 ?an ! repair ( ! small coils us$ on int]val1 revolv+ magnets4 ,z f> z satisfactory op]at+ qualities are conc]n$1 inductor alt]nators & ^? ) revolv+ magnets seem to be on an equality1 b = /ructural reasons inductor alt]nators w probably be built less freely 9 ! future ?an 9 ! pa/4 ,ne>ly all long transmissions are n[ c>ri$ out ) ei!r two- or ?ree-phase curr5t4 ,! mo/ notable two-phase in/allation is t at ,niag>a ,falls1 :]e ! orig9al t5 g5]ators1 z well z ! elev5 dynamos lat] add$ 9 two ( ! l>ge plants1 are all ( ! two-phase type4 ,at ,caon ,f]ry1 ,mont41 ! fir/ f\r ( ! #gej-kil[att g5]ators 7 two-phase1 b ! six ma*9es ( l capacity in/all$ lat] are ?ree-phase4 ,9 ! late/ plants ( l>ge capacity or involv+ v long transmissions ?ree-phase ma*9es h be5 g5]ally employ$4 ,?is is true ( ! ,colgate & ,electra plants 9 ,cali=nia1 & ( t at ,sault ,/e4 ,m>ie1 ,mi*4 ,illu/ration3 ,,fig4 #dg4--;,int]ior ( ,p[]-h\se at ,g>v9's ,falls on ! ,m]rimac ,riv]4 ,illu/ration3 ,,fig4 #dh4--ejj-,kil[att ,g5]ator 9 ,/ation at ,great ,falls on ! ,presumpscot ,riv]4 ,z to frequ5cy1 exi/+ practice ext5ds all ! way f #acc cycles p] second on ! l9es at ,m>ysville1 ,cal41 d[n to only #ae cycles on ! transmission = ! ,wa%+ton ,baltimore ,electric ,railway4 ,m common practice ranges betwe5 #be & #fj cycles4 ,niag>a ,falls saw ! fir/ great plant in/all$ = #be cycles1 b o!rs ( t frequ5cy are n[ engag$ 9 ! supply ( light & p[] = g5]al di/ribution4 ,= transmission to electric railway l9es a frequ5cy ( #be cycles has be5 & is be+ widely us$1 prom95t examples ( :i* may be se5 9 ! ,new ,hamp%ire traction1 ! ,b]k%ire1 & ! ,albany ,hudson sy/ems4 ,illu/ration3 ,,fig4 #di4--;,columbus1 ,ga41 ,wat]-p[] ,/ation4 ,! /rong feature ( a sy/em at #be cycles is t x is well suit$ to ! supply ( cont9u\s curr5ts ?r\gh rot>y conv]t]s ) reasonable numb]s ( poles1 armature slots1 & commutator b>s4 ,illu/ration3 ,,fig4 #ej4--ajfe-,kil[att1 #bcjj volt ,g5]ator ,connect$ to ,motor 9 ,%aw9igan ,sub-/ation at ,montreal4 ,on ! o!r h&1 ! co/ ( trans=m]s is great] ) curr5t at #be cycles p] second ?an ) a high] frequ5cy1 & ?is curr5t is only j be>able = inc&esc5t light+ & q unsuit$ = arc lamps1 because ( ! fluctuat+ "* ( ! light produc$4 ,at #ae cycles p] second a curr5t c be employ$ = inc&esc5t light+ ) satisfactory results only by means ( "s special devices1 z lamps ) v ?ick filam5ts1 to avoid ! flick]4 ,v l[ fluctuations cut d[n undesirable effects 9 ! way ( inductance & resonance1 b ^! effects c be avoid$ to a l>ge degree 9 o!r ways4 ,:]e p[] is ! mo/ important elem5t 9 ! s]vice ( an electric wat]-p[] & transmission sy/em !re is a decid$ t5d5cy to adopt a r small numb] ( p]iods = ! sy/em1 ev5 at "s disadvantage z to light+ facilities4 ,?is is illu/rat$ by ! transmission f ,/4 ,an?ony's ,falls1 ,m9n41 at #ce cycles1 f ,caon ,city to ,cripple ,creek1 ,col41 at #cj cycles1 by ! ,sault ,/e4 ,m>ie plant ( #cb1jjj kil[atts at #cj cycles1 z well z by ! two ,niag>a ,falls plants ( #gh1gej kil[atts at #be cycles4 ,:]e ! ma9 purpose ( a transmission sy/em is ! supply ( light & p[] = g5]al di/ribution1 sixty p]iods p] second are adopt$ z ! /&>d 9 _m cases4 ,?is numb] ( p]iods 9 comp>ison ) a small] "o t5ds to increase ! co/ ( rot>y conv]t]s b decreases ! co/ ( trans=m]s1 & is suitable = bo? inc&esc5t & arc light+4 ,illu/ration3 ,,fig4 #ea4--;,effici5cy ,curves = ,motor ,g5]ators at ,montreal ,sub-/ation ( ! ,%aw9igan ,transmission ,l9e4 ,few1 if any1 transmission sy/ems h rec5tly be5 in/all$ = frequ5cies above sixty cycles1 & ! old] plants t work$ at high] figures h 9 mo/ cases be5 remodell$4 ,dur+ ! pa/ decade ! voltages ( alt]nators h be5 greatly increas$1 b h n caught up ) ! dem& = high pressures on long-transmission l9es4 ,t5 ye>s ago :5 ! fir/ long transmissions 7 go+ into op]ation #b1jjj volts 0 consid]$ high = an alt]nator4 ,z ?is voltage is too l[ = economy ( conductors long] ?an ?ree or f\r miles1 ! important e>ly transmissions 7 all c>ri$ out ) ! aid ( /ep-up trans=m]s at g5]at+ /ations4 ,! practice !n 01 & to a l>ge ext5t /ill is1 to design ! alt]nators = a transmission ) a voltage well suit$ to _! economical con/ruction1 & !n give ! /ep-up trans=m]s any ratio necess>y to atta9 ! requir$ l9e voltage4 ,,alt]nators ,,9 ,,transmission ,,sy/ems4 ---------------------------------------- ---------------------------- ,numb] at ,plant4 ,kil[atts ,ea*4 ,alt]nator ,voltage4 ,phase4 ,cycles4 ,r4 ,p4 ,m4 ,type ( ,location ( ,sy/em4 ,magnet4 ,me?od ( ,connec- tions4 ---------------------------------------- --------------------- ,niag>a ,falls,a #afc1gej #b1cjjbbe #bej ,ext]nal ,direct revolv+ ,niag>a ,falls,a #ec1gej #b1cjjbbe #bej ,int]nal ,colgate to ,oakl& #cb1bej #b1djjcfj #bhe ,inductor ,colgate to ,oakl& #da1abe #b1djjcfj #djj ,electra to ,s4,francisco #eb1jjj 4444#cfj #bdj ,portsm\? to ,pelh'm #ab1jjjac1bjjcbe #hc4c;,int]nal ,portsm\? to ,pelh'm #ba1jjjac1bjjcbe #id ,virg9ia ,city #b #gej #ejjcfj #djj ,ext]nal ,ogd5 ,salt ,lake #e #gej #b1cjjcfj #cjj ,int]nal ,*audire ,falls #b #gejaj1ejjcff4fdjj ,yadk9 ,riv] ,falls #b #gejab1jjjcff #aff ,lewi/on1 ,me4 #c #gejaj1jjjcfj #ahj ,f>m+ton ,riv] to #b #gej #ejjcfj 444 ,h>t=d1 ,conn4 #b #fjj #ejjbfj 444 ,caon ,f]ry to ,butte #aj #gej #ejjcfj #aeg ,apple ,riv4 to ,/4 ,paul #d #gej #hjjcfj #cjj ,edison ,co41 ,l4 ,angeles #d #gjj #gejcej 444 ,madrid to ,bl& #b #fjj #fjecfj #ij ,caon ,city to ,cripple ,creek #c #dej #ejjccj 444 44444 ,sault ,/e4 ,m>ie #hj #djj #b1djjccj #ahj ,/4 ,hyac9!1 ,que4 #c #ahj #b1ejjcfj #fjj ,great ,falls to ,portl&1 ,me4 #d #ejjaj1jjjcfj #bbe ---------------------------------------- --------------------- ,a ,niag>a ,falls ,p[] ,company4 ,?us 9 ! two wat]-p[] plants connect$ ) ! electrical supply sy/em ( ,h>t=d1 ,conn41 ! alt]nators op]ate at #ejj volts ) trans=m]s t put ! l9e voltage up to #aj1jjj4 ,9 ! /ation on ,apple ,riv] t supplies ! light+ sy/em ( ,/4 ,paul1 ,m9n41 ! alt]nators op]ate at #hjj volts1 & ?is is rais$ to #be1jjj volts = ! l9e4 ,at ,caon ,f]ry ! alt]nator voltage ( #ejj is multipli$ by #ajj 9 ! trans=m]s giv+ #ej1jjj on ! l9e4 ,illu/ration3 ,,fig4 #eb4--,transmission ,l9e ( ,new ,hamp%ire ,traction ,company4 ,:]e ! g5]at+ /ation ( a transmission sy/em is locat$ close to a "p ( its load ! alt]nators are giv5 a voltage suitable = di/ribution1 say ab\t #b1djj1 & any desir$ pressure on ! l9e is !n obta9$ by means ( /ep-up trans=m]s4 ,two ( ! ,niag>a ,falls plants are an illu/ration ( ?is practice1 ! voltage ( all ! alt]nators !re be+ #b1bjj1 :i* is rais$ to #bb1jjj = ! transmission ( a "p ( ! en]gy to ,buffalo4 ,a simil> practice is foll[$ 9 ! wat]-p[] plant at ,ogd51 :]e ! g5]ators furni% curr5t at #b1cjj volts = local di/ribution1 & trans=m]s raise ! pressure to #bf1jjj volts = ! transmission to ,salt ,lake ,city4 ,9 ! #cb1jjj-kil[att plant at ,sault ,/e4 ,m>ie1 ,mi*41 ! alt]nators op]ate at #b1djj volts & a l>ge "p ( _! load is local1 b ?is voltage w no d\bt be rais$ by trans=m]s :5 transmission l9es are op]at$4 ,= g5]at+ /ations t c>ry little or no local loads ! co/ ( trans=m]s c be sav$ if ! g5]ators develop ! voltage requir$ on ! transmission l9es4 ,?is possible sav+ has l$ to ! developm5t ( alt]nators t g5]ate voltages z high z #ae1jjj 9 _! armature coils4 ,su* alt]nators h /ation>y armatures 9 all cases & are ( ei!r ! revolv+ magnet or inductor type4 ,at ! pres5t "t _m transmission sy/ems 9 ! ,unit$ ,/ates op]at+ at #aj1jjj or m volts develop ^! pressures 9 ! armature coils ( _! alt]nators1 & ! numb] ( su* sy/ems is rapidly increas+4 ,x is n[ ! rule r ?an ! exception to disp5se ) /ep-up trans=m]s on new "w :]e ! l9e voltage is any?+ "u #ae1jjj4 ,p]haps ! longe/ transmission l9e n[ 9 regul> op]ation ) curr5t f ! armature coils ( an alt]nator is t at #ac1bjj volts betwe5 ! g5]at+ /ation at ,portsm\? & "o ( ! sub-/ations ( ! ,new ,hamp%ire ,traction sy/em at ,pelham1 a di/ance ( =ty-two miles4 ,9 at lea/ "o transmission sy/em n[ "u con/ruction1 t ( ! ,wa%+ton1 ,baltimore ,annapolis ,electric ,railway1 ! voltage ( g5]ators to supply ! l9e )\t ! int]v5tion ( /ep-up trans=m]s w be #ae1jjj4 ,! company mak+ ^! alt]nators is said to be ready to supply o!rs t g5]ate #bj1jjj volts 9 ! armature coils :5ev] ! dem& = !m is made4 ,9 q a numb] ( cases alt]nators ( ab\t #ac1jjj volts h be5 in/all$ = transmissions along electric railway l9es4 ,alt]nator ,sy/ems ,us+ ,high-voltage ,alt]nators4 ,voltages4 ,electrical ,developm5t ,co4 ( ,ont>io1 ,niag>a ,falls #ab1jjj ,light+ & ,/reet ,railway1 ,man*e/]1 ,n4 ,h4 #aj1jjj ,light+ & ,/reet ,railway1 ,man*e/]1 ,n4 ,h4 #ab1ejj ,light+ & ,p[]1 ,portl&1 ,me4 #aj1jjj ,light+ & ,p[]1 ,nor? ,gorham1 ,me4 #aj1jjj ,mallison ,p[] ,co41 ,we/brook1 ,me4 #aj1jjj ,light+ & ,p[]1 ,lewi/on1 ,me4 #aj1jjj ,electric ,railway1 ,portsm\?1 ,n4 ,h4 #ac1bjj ,electric ,railway1 ,pittsfield1 ,mass4 #ab1ejj ,ludl[ ,mills1 ,ludl[1 ,mass4 #ac1bjj ,electric ,railway1 ,bo/on to ,worce/]1 ,mass4 #ac1bjj ,electric ,railway1 ,albany ,hudson1 ,n4 ,y4 #ab1jjj ,empire ,/ate ,p[] ,co41 ,am/]dam1 ,n4 ,y4 #ab1jjj ,lehigh ,p[] ,co41 ,ea/on1 ,pa4 #ab1jjj ,hudson ,riv] ,p[] ,co41 ,me*anicsville1 ,n4 ,y4 #ab1jjj ,light & ,p[]1 ,&]son1 ,s4 ,c4 #aa1jjj ,fries ,mfg4 ,co41 ,salem1 ,n4 ,c4 #ab1jjj ,light & ,p[]1 ,ouray1 ,col4 #ab1jjj ,wa%+ton ,baltimore ,electric ,railway #ae1jjj ,canadian ,niag>a ,p[] ,co41 ,niag>a ,falls #ab1jjj ,ont>io ,p[] ,co41 ,niag>a ,falls #ab1jjj ,?is li/ ( high-voltage alt]nators is n int5d$ to be exhau/ive1 b s]ves to indicate _! wide application4 ,if su* alt]nators c be pur*as$ at a l[] price p] unit ( capacity ?an alt]nators ( l[ voltage plus /ep-up trans=m]s1 !re is an app>5t advantage = transmission sy/ems 9 ! high-voltage ma*9es4 ,?is advantage may re/ 9 "p on a high] effici5cy 9 ! alt]nators t yield ! l9e voltage ?an 9 ! comb9ation ( l[-voltage alt]nators plus /ep-up trans=m]s4 ,x is n c]ta91 h[ev]1 t depreciation & repairs on ! g5]ators ( high voltage w n be mat]ially great] ?an ! l *>ges on g5]ators ( l[ voltage1 & "s advantage 9 price %\ld be requir$ to cov] ?is cont+5cy4 ,j h[ f> up ! voltage ( alt]nators c be pu%$ = practical purposes is unc]ta91 b x seems t ! limit mu/ be mu* bel[ t = trans=m]s :]e !re is ample room = solid insulation & ! coils c be imm]s$ 9 oil4 ,! use ( g5]ators at #aj1jjj volts & above t5ds to l[] ! volts p] mile on transmission l9es1 because x seems bett] 9 "s cases to increase ! weight ( l9e conductors r ?an to add /ep-up trans=m]s1 z 9 ! #db-mile transmission f ,portsm\? to ,pelham4 ,,*apt] ,x4 ,,trans=m]s ,,9 ,,transmission ,,sy/ems4 ,trans=m]s are almo/ always necess>y 9 long electric sy/ems ( transmission1 because ! l9e voltage is great] ?an t ( g5]ators1 or at lea/ t ( di/ribution4 ,z trans=m]s at ei!r g5]at+ or receiv+ /ations repres5t an increase ( inve/m5t )\t correspond+ increase ( work+ capacity1 & also an additional loss 9 op]ation1 x is desirable to avoid _! use z f> z is practicable4 ,9 %ort transmissions ov] di/ances ( less ?an fifte5 miles x is g5]ally bett] to avoid ! use ( trans=m]s at g5]at+ /ations1 & 9 "s ( ^! cases1 :]e ! transmission is only two or ?ree miles1 x is ev5 m economical to omit trans=m]s at ! sub-/ations4 ,?us1 :]e en]gy is to be transmitt$ two miles & !n appli$ to l>ge motors 9 a factory1 or di/ribut$ at #b1ejj volts1 ! co/ ( b>e copp] conductors = ! ?ree-phase transmission l9e w be only ab\t #f p] kil[att ( l9e capacity at #b1ejj volts1 ) copp] at #ae c5ts p] p\nd1 & a loss ( #e p] c5t at full load4 ,! av]age loss 9 su* a l9e w probably be z small z t 9 "o set ( trans=m]s & a l9e ( high] voltage4 ,fur!rmore1 ! fir/ co/ ( ! #b1ejj-volt g5]ators & l9e )\t trans=m]s w be less ?an t ( g5]ators & l9e ( high] voltage ) /ep-d[n trans=m]s at ! sub-/ation4 ,z g5]ators up to #ac1ejj volts are n[ regul>ly manufactur$1 x is q common to omit /ep-up trans=m]s at ! ma9 /ations ( r %ort transmission sy/ems4 ,?is practice 0 foll[$ 9 ! #ac1ejj-volt transmission to ,man*e/]1 ,n4 ,h41 ! #aj1jjj-volt transmission to ,lewi/on1 ,me41 & ! #ab1jjj-volt transmission to ,salem1 ,n4 ,c4 ,9 mo/ transmission ov] di/ances ( tw5ty-five miles or m1 /ep-up trans=m]s at g5]at+ /ations z well z /ep-d[n trans=m]s at sub-/ations are employ$4 ,z yet ! highe/ voltages t h be5 put into practical use on transmission l9es 7t is1 #ej1jjj to #fj1jjj7 are mu* bel[ ! pressures t h be5 yield$ by trans=m]s 9 exp]im5tal "w4 ,^! latt] voltages h 9 a numb] ( in/ances gone above #ajj1jjj4 ,! numb]s & capacities ( trans=m]s us$ at ma9 /ations v>y mu* 9 _! relation to ! numb]s & individual capacities ( g5]ators !re4 ,9 "s cases !re are ?ree times z _m trans=m]s z ?ree-phase g5]ators1 & ! capacity ( ea* trans=m] is ei!r equal to or some:at great] ?an "o-?ird ( ! capacity ( ea* g5]ator4 ,illu/ration3 ,,fig4 #ec4--,trans=m]s at ,c5tral ,sub-/ation1 ,montreal4 ,?us 9 ! /ation at ,spi] ,falls on ! ,hudson1 :5ce p[] is transmitt$ to ,albany & o!r cities1 ! numb] ( /ep-up trans=m]s w be ?irty & _! aggregate capacity w be #bd1jad kil[atts1 :ile ! total numb] ( ?ree-phase g5]ators w be t51 ) a comb9$ capacity ( #bd1jjj kil[atts4 ,ano!r practice is to give ea* trans=m] a capacity great] ?an "o-?ird ( t ( ! ?ree-phase g5]ator ) :i* x is to be connect$1 & make ! total numb] ( trans=m]s less ?an ?ree times z great z ! numb] ( g5]ators4 ,an example ( ?is sort exi/s 9 ! /ation on ,apple ,riv]1 :5ce p[] is transmitt$ to ,/4 ,paul4 ,?is /ation conta9s f\r ?ree-phase g5]ators ( #gej kil[atts ea*1 & six trans=m]s ( #ejj kil[atts ea*1 ^! latt] be+ connect$ 9 two sets ( ?ree ea*4 ,! use ( ?ree trans=m]s = ea* ?ree-phase g5]ator in/ead ( ?ree trans=m]s = ea* two or ?ree g5]ators1 t5ds to keep trans=m]s fully load$ :5 9 use1 & !re=e to increase _! effici5cy4 ,on ! o!r h&1 effici5cy increases a little ) ! size ( trans=m]s1 & ! fir/ co/ p] unit capacity is apt to be less ! great] ! size ( ea*4 ,ano!r solution ( ! problem is to provide "o trans=m] = ea* ?ree-phase g5]ator1 ea* trans=m] be+ w\nd ) ?ree sets ( coils1 s t ! entire output ( a g5]ator c be s5t into x4 ,?is practice is foll[$ at ! ,ho*feld5 wat]-p[] /ation1 :5ce p[] is transmitt$ to ,o]likon1 ,switz]l&1 also 9 ! wat]-p[] /ation at ,gr5oble1 ,france1 :5ce en]gy at #bf1jjj volts is transmitt$ to a numb] ( factories4 ,) ?ree-phase trans=m]s ea* g5]ator & its trans=m] may =m an indep5d5t unit t c be connect$ ) ! l9e at pleasure1 ?us t5d+ to keep trans=m]s at full load4 ,?\gh ?ree-phase trans=m]s are mu* us$ 9 ,europe1 !y h ?us f> _h little application 9 ! ,unit$ ,/ates4 ,s+le-phase trans=m]s may1 ( c\rse1 be limit$ 9 numb] to t ( ! ?ree-phase g5]ators ) :i* !y are us$1 b su* trans=m]s mu/ regul>ly be connect$ to ! g5]ators & l9e 9 gr\ps ( two or ?ree4 ,su* an equipm5t 0 provid$ 9 "p at ! #g1ejj-kil[att /ation on ! ,miss\ri ,riv] at ,caon ,f]ry1 :i* conta9s t5 ?ree-phase g5]ators ( #gej kil[atts ea*4 ,! trans=m]s at ?is /ation include twelve ( #cbe kil[atts ea*1 connect$ 9 f\r gr\ps ( ?ree ea*1 also six trans=m]s ( #iej kil[atts ea* :i* are also connect$ 9 gr\ps ( ?ree4 ,?ree ( ^! l>g] trans=m]s h a capacity ( #b1hej kil[atts1 or ne>ly equal to t ( f\r g5]ators4 ,) two-phase g5]ators s+le-phase trans=m]s mu/ be connect$ 9 pairs1 & x is common to provide two trans=m]s = ea* g5]ator4 ,?us1 9 ! ,ra9b[ /ation on ! ,f>m+ton ,riv]1 :5ce en]gy is transmitt$ to ,h>t=d1 !re are two g5]ators ( ! two-phase type & rat$ at #fjj kil[atts ea*1 also f\r trans=m]s rat$ at #cjj kil[atts ea*4 ,z ! regulation ( trans=m]s on ov]loads is n z good z t ( g5]ators1 x seems good practice to give ea* gr\p ( trans=m]s a some:at great] capacity ?an t ( ! g5]ator or g5]ators ^: en]gy is to pass ?r\gh x4 ,?is plan 0 app>5tly foll[$ at ! ,caon ,f]ry /ation1 :]e ! total g5]ator capacity is #g1ejj kil[atts & ! total capacity ( /ep-up trans=m]s is #i1fjj kil[atts4 ,ea* gr\p ( ! #cbe-kil[att trans=m]s !re has a capacity ( #ige kil[atts1 :ile ea* g5]ator is only ( #gej kil[atts4 ,usually ! numb] ( gr\ps ( trans=m]s at a two-phase or ?ree-phase g5]at+ /ation is made great] ?an ! numb] ( transmission circuits suppli$ by ! /ation1 = "s ( ! reasons j consid]$4 ,:5 ?is is n ! case x is commonly desirable 9 any ev5t to h z _m gr\ps ( /ep-up trans=m]s z !re are transmission circuits1 s t ea* circuit may be op]at$ ) trans=m]s t are indep5d5t ( ! o!r circuits4 ,at sub-/ations x is desirable to h a gr\p ( trans=m]s = ea* transmission circuit1 & x may be necess>y to subdivide ! trans=m] capacity /ill fur!r 9 ord] to keep trans=m]s 9 op]ation at ne>ly full load1 or to provide a gr\p ( trans=m]s = ea* sort ( s]vice or = ea* di/ribution circuit4 ,all ( ! trans=m]s at a sub-/ation %\ld h a total capacity at lea/ equal to t ( ! g5]ators ^: en]gy !y are to receive1 m9us ! losses 9 /ep-up trans=m]s & ! l9e4 ,trans=m]s at sub-/ations d n necess>ily correspond 9 numb] or individual capacity ) ^? at g5]at+ /ations1 & ! numb] ( sub-/ation trans=m]s be>s no necess>y relation to ! numb] ( g5]ators by :i* !y are f$4 ,two transmission circuits ext5d f ,caon ,f]ry to a sub-/ation at ,butte1 & 9 t sub-/ation !re are six trans=m]s divid$ into two gr\ps = ?ree-phase op]ation1 ea* trans=m] be+ rat$ at #iej kil[atts4 ,?is sub-/ation equipm5t ?us corresponds to only ! six #iej-kil[att trans=m]s 9 ! g5]at+ /ation1 because ! f\r gr\ps ( small] trans=m]s !re are us$ to supply ! transmission l9e to ,hel5a4 ,9 ! sub-/ation at ,/4 ,paul t receives ! entire output ( ! plant on ,apple ,riv]1 :]e ! six trans=m]s ( #ejj kil[atts ea* are locat$1 t5 trans=m]s receive en]gy f two ?ree-phase transmission circuits4 ,six ( ^! trans=m]s are rat$ at #cjj kil[atts ea*4 ,! #cjj-kil[att trans=m]s are connect$ 9 two gr\ps ( ?ree ea*1 & ! #bjj-kil[att 9 two gr\ps ( two ea*1 trans=m+ curr5t f ?ree-phase to two-phase4 ,! aggregate capacity ( ! sub-/ation trans=m]s is ?us #b1fjj kil[atts1 :ile t ( trans=m]s at ! g5]at+ /ation is #c1jjj kil[atts4 ,) f\r g5]ators at ! wat]-p[] plant !re are t5 trans=m]s at ! sub-/ation1 :]e all ! en]gy1 m9us losses1 is deliv]$4 ,at ,wat]vliet1 :]e "o ( ! sev]al sub-/ations ( ! sy/em ) its l>g] g5]at+ plant at ,spi] ,falls is locat$1 ! capacity ( ea* trans=m] is #a1jjj kil[atts1 ?\gh ea* trans=m] at ,spi] ,falls has a rat+ bel[ ?is figure4 ,9 ! sub-/ation at ,man*e/]1 ,n4 ,h41 t receives ne>ly all ( ! en]gy f f\r wat]-p[] plants1 conta9+ eight g5]ators ) an aggregate capacity ( #d1jcj kil[atts1 !re are locat$ tw5ty-"o /ep-d[n trans=m]s t h a total rat+ ( #d1bjj kil[atts4 ,^! tw5ty-"o trans=m]s are f$ by six circuits1 ( :i* five are ?ree-phase & "o is two-phase4 ,a "p ( ! trans=m]s supply curr5t to motor-g5]ators1 develop+ #ejj-volt curr5t = a /reet railway1 & ! rema9+ trans=m]s fe$ circuits t di/ribute alt]nat+ curr5t4 ,f ^! examples x may be se5 t 9 practice ei!r "o or m gr\ps ( trans=m]s are employ$ 9 sub-/ations = ea* transmission circuit1 t ! total numb] ( ^! trans=m]s may be j equal to or sev]al times t ( ! g5]ators f :i* !y receive en]gy1 & t ! individual capacities ( ! trans=m]s range f less ?an "o-?ird to m ?an t ( a s+le g5]ator4 ,gr\ps ( trans=m]s at a ma9 /ation mu/ correspond 9 voltage ) t ( ! g5]ators 9 ! prim>y & t ( ! transmission l9e 9 ! second>y w9d+s4 ,sub-/ation trans=m]s receive curr5t at ! l9e voltage & deliv] x at any ( ! pressures desir$ = local di/ribution4 ,:]e /ep-up trans=m]s are employ$ ! g5]ator pressure 9 ne>ly all cases is at "s po9t betwe5 #ejj & #b1ejj volts4 ,at ! ,caon ,f]ry /ation ! voltage ( trans=m]s is #eej 9 9 ! prim>y & #ej1jjj 9 ! second>y w9d+s4 ,9 ! ,colgate p[]-h\se1 :5ce en]gy is transmitt$ to ,oakl&1 ! g5]ator pressure ( #b1djj volts is rais$ to #dj1jjj volts by trans=m]s4 ,g5]ator voltage 9 ! p[]-h\se on ,apple ,riv] is #hjj & trans=m]s put ! pressure up to #be1jjj = ! l9e to ,/4 ,paul4 ,trans=m]s at ! ,niag>a ,falls /ation raise ! voltage f #b1bjj to #bb1jjj = ! transmission to ,buffalo4 ,z trans=m]s c be w\nd = any desir$ ratio ( voltages 9 _! prim>y & second>y coils1 a g5]ator pressure t w all[ ! mo/ economical con/ruction c be select$ :]e /ep-up trans=m]s are employ$4 ,9 g5]al x may be said t ! great] ! capacity ( ea* g5]ator1 ! high] %\ld be its voltage & t ( ! prim>y coils ( /ep-up trans=m]s1 = economical con/ruction4 ,at sub-/ations ! requirem5ts ( di/ribution mu/ obvi\sly fix ! second>y voltages ( trans=m]s4 ,weight & co/ ( trans=m]s dep5d 9 "p on ! frequ5cy ( ! alt]nat+ curr5t employ$1 trans=m]s be+ light] & *eap] ! high] ! numb] ( cycles complet$ p] second by _! curr5t1 o!r factors rema9+ con/ant4 ,9 spite ( ?is fact ! t5d5cy dur+ "s ye>s has be5 t[>d l[] frequ5cies1 because ! l[] frequ5cies pres5t m>k$ advantages z to inductive effects 9 transmission sy/ems1 ! di/ribution ( p[] ?r\gh induction motors1 ! con/ruction & op]ation ( rot>y conv]t]s1 & ! con/ruction ( g5]ators4 ,in/ead ( ! #acc cycles p] second t 7 common 9 alt]nat+ sy/ems :5 long transmissions fir/ became important1 sixty cycles p] second is n[ ! mo/ g5]al rate ( curr5t *anges 9 su* transmission sy/ems4 ,b practice is con/antly ext5d+ to /ill l[] frequ5cies4 ,! fir/ ,niag>a ,falls plant ) its tw5ty-five cycles p] second rea*$ ! l[] limit = g5]al di/ribution1 because inc&esc5t light+ is b>ely satisfactory & arc light+ decid$ly undesirable at ?is figure4 ,9 contra/ ) ! great transmissions f ,caon ,f]ry to ,butte1 ,colgate to ,oakl&1 & ,electra to ,san ,francisco1 :i* op]ate at sixty cycles1 ! sy/em betwe5 ,caon ,city & ,cripple ,creek1 9 ,colorado1 z well z ! great plant at ,sault ,/e4 ,m>ie1 employs ?irty-cycle curr5t1 & ! l9es f ,spi] ,falls to ,s*5ectady1 ,albany1 & ,troy are int5d$ = curr5t at =ty cycles p] second4 ,f ^! examples x may be se5 t ! bulk & co/ ( trans=m]s is n ! controll+ factor 9 ! selection ( curr5t frequ5cy 9 a transmission sy/em4 ,illu/ration3 ,,fig4 #ed4--;,fir/ ,floor ( ,s>atoga ,sub-/ation4 ,trans=m]s us$ at ei!r g5]at+ or sub-/ations are cool$ by special means 9 _m cases4 ,! advantages ( s-call$ artificial cool+ are small] weight & fir/ co/ 9 trans=m]s1 & p]haps long] life = ! insulation ( w9d+s4 ,= ^! advantages a small increase 9 ! co/ ( op]ation mu/ be paid4 ,/ation trans=m]s are usually cool$ ei!r by =c+ air ?r\gh _! cases "u pressure1 or else by pass+ wat] ?r\gh pipes 9 ! oil ) :i* ! trans=m] cases are fill$4 ,if cool+ ) air-bla/ is adopt$1 a bl[]1 ) electric motor or "s o!r s\rce ( p[] to op]ate x1 mu/ be provid$4 ,:]e trans=m]s are oil-insulat$ & cool$ ) wat] !re mu/ be "s pressure to ma9ta9 ! circulation4 ,if free wat] "u a suitable head c be _h = ! cool+ ( trans=m]s1 z 9 mo/ wat]-p[] plants1 ! co/ is v slight4 ,:]e wat] mu/ be pur*as$ & pump$ ?r\gh ! trans=m]s its co/ w usually be great] ?an t ( cool+ ) air-bla/4 ,"o manufactur] gives ! foll[+ z approximate figures = ! rate at :i* wat] at ! temp]ature ( #ae c5tigrade mu/ be =c$ ?r\gh 8 trans=m]s to prev5t a rise ( m ?an #ce c5tigrade 9 _! temp]ature1 probably :5 op]at+ "u full loads4 ,trans=m]s--,kil[atts4 ,gallons p] m9ute4 #aej #j4e #djj 4#ge #djj #a4jj #a1jjj #a4e #ge 4#cg ,an air-bla/ to cool trans=m]s at ma9 or sub-/ations may be provid$ 9 ei!r ( two ways4 ,"o plan is to con/ruct an air-tight comp>tm5t1 locate ! trans=m]s ov] op5+s 9 its top1 & ma9ta9 a pressure 9 ! comp>tm5t by means ( bl[]-fans t draw cool air f outside4 ,su* an arrangem5t has be5 c>ri$ out at ! sub-/ation 9 ,man*e/]1 ,n4 ,h4 ,! basem5t und]nea? ?is sub-/ation is air-tight1 & 9 ! concrete floor ov] x !re are tw5ty-sev5 rectangul> op5+s1 ea* tw5ty-five by ?irty in*es1 & int5d$ = ! location ( a #bjj-kil[att trans=m]4 ,aggregate trans=m] capacity ov] ^! op5+s w ?us be #e1djj kil[atts4 ,pressure 9 ?is basem5t is ma9ta9$ by draw+ outside air ?r\gh a metal duct t t]m9ates 9 a hood on ! outside ( ! sub-/ation ab\t n9e feet above ! gr\nd4 ,9 ! ro( ( ?is sub-/ation !re are ample skylight op5+s to p]mit ! exit ( hot air t has be5 =c$ ?r\gh ! trans=m]s4 ,9 ! air-tight basem5t are two electric motors ( t5 horse-p[] ea*1 connect$ to ! bl[] t ma9ta9s ! pressure4 ,x may be not$ t 9 ?is case !re is less ?an "o-horse p[] ( motor capacity = ea* #bjj kil[atts capacity 9 trans=m]s4 ,:]e !re are n m ?an six or n9e trans=m]s to be cool$1 x is common practice to provide a sep>ate motor & bl[] = ea* gr\p ( ?ree trans=m]s1 & lead ! air directly f ea* bl[] to its gr\p ( trans=m]s by a metal duct1 ?us avoid+ ! necessity = an air-*amb]4 ,9 su* cases a bl[] giv+ a ?ree-eigh?-ounce air pressure p] squ>e in* & a motor ( "o horse-p[] capacity are g5]ally provid$ = ea* gr\p ( ?ree trans=m]s rat$ at #ajj to #aej kil[atts ea*4 ,:]e cool+ ) air-bla/ is adopt$1 oil-insulation _c be c>ri$ out because ! air mu/ come into intimate contact ) ! trans=m] coils & core4 ,bo? oil-insulation ) wat] cool+ & dry insulation ) cool+ by air-bla/ h be5 widely us$ 9 transmission sy/ems ( l>ge capacity & high voltage4 ,9 ! ,colgate plant1 :]e ! l9e pressure is #dj1jjj volts1 ! #gjj-kil[att trans=m]s are oil-insulat$ & wat]-cool$1 & ?is is also true ( ! #iej-kil[att trans=m]s 9 ! #ej1jjj-volt transmission betwe5 ,caon ,f]ry & ,butte4 ,on ! o!r h&1 ! transmission sy/em betwe5 ,spi] ,falls1 ,s*5ectady1 & ,albany1 c>ri$ out at #bf1ejj volts1 includes trans=m]s t range f sev]al hundr$ to #a1jjj kil[atts ea* 9 capacity & are all air-cool$4 ,ei!r a wat]-cool$ trans=m] or "o cool$ by air-bla/ may be safely ov]load$ to "s ext5t1 if ! circulation ( air or wat] is s increas$ t ! ov]load does n cause heat+ beyond ! all[able temp]ature4 ,! circulation ( air or wat] ?r\gh a trans=m] %\ld nev] be =c$ to an ext5t t cools ! trans=m] bel[ ! temp]ature ( ! air 9 ! room :]e x is locat$1 z ?is w cause ! cond5sation ( wat] on its p>ts4 ,9 "s cases x is desirable t means = ! regulation ( trans=m] voltages ?r\gh a range ( t5 p] c5t or m ea* way f ! normal be provid$4 ,?is result is rea*$ by ! connection ( a numb] ( sections at "o end ( ! trans=m] w9d+ to a t]m9al bo>d1 :]e !y may be cut 9 or out ( action at w4 ,regulation is usually desir$1 if at all1 9 a second>y w9d+ ( comp>atively l[ voltage1 & ! regulat+ sections g5]ally =m a "p ( su* w9d+1 b ^! sections may be locat$ 9 ! prim>y w9d+4 ,9 ord] to keep ! numb] ( trans=m]s small] & ! capacity ( ea* l>g] ?an x w\ld o!rwise be1 x is practicable to divide ! l[-voltage second>y w9d+ ( ea* trans=m] into two or m p>ts t h no electrical connection ) ea* o!r4 ,^! diff]5t p>ts ( ! w9d+ may !n be connect$ to di/9ct di/ribution l9es or o!r s]vices4 ,an example ( ?is sort exi/s 9 ! ,hooksett sub-/ation ( ! ,man*e/]1 ,n4 ,h41 transmission sy/em4 ,?ree-phase curr5t at ab\t #aa1jjj volts ent]s ! prim>y w9d+s ( ?ree trans=m]s at ?is sub-/ation4 ,ea* ( ^! trans=m]s has a s+le prim>y1 b two di/9ct second>y w9d+s4 ,?ree ( ^! second>ies1 "o on ea* trans=m]1 are connect$ toge!r & fe$ a rot>y conv]t] at ab\t #chj volts1 ?ree-phase4 ,! o!r ?ree second>y w9d+s are connect$ 9 l mann] to a second rot>y conv]t]4 ,ea* ( ^! trans=m]s is rat$ at #bej kil[atts1 & ea* rot>y is rat$ at #cjj kil[atts1 s t ! trans=m] capacity am\nts to #gej kil[atts & t ( ! conv]t]s to #fjj kil[atts1 giv+ a desirable m>g9 ( trans=m] capacity = railway s]vice4 ,) ! ord9>y me?od ( connection & w9d+s1 six trans=m]s ( #abe kil[atts ea* w\ld h be5 requir$ 9 ?is sub-/ation4 ,high voltage = transmission l9es may be obta9$ by ! comb9ation ( two or m trans=m]s ) _! second>y coils 9 s]ies4 ,?is me?od 0 foll[$ 9 "s ( ! e>ly transmissions1 z 9 t at #aj1jjj volts to ,san ,b]n>d9o & ,pomona1 begun 9 #ahia1 :]e tw5ty trans=m]s1 giv+ #ejj volts ea*1 7 us$ ) _! high-voltage coils 9 s]ies4 ,"s disadvantages ( su* an arrangem5t are its high co/ p] unit ( trans=m] capacity & its l[ effici5cy4 ,9 a s+le-phase sy/em ! maximum l9e pressure mu/ be develop$ or receiv$ 9 ! coils ( ea* trans=m]1 unless two or m are connect$ 9 s]ies4 ,?is is also true z to ei!r phase ( a two-phase sy/em ) indep5d5t circuits4 ,9 ?ree-phase circuits ! coils ( a trans=m] connect$ betwe5 ei!r two wires obvi\sly op]ate at ! full l9e pressure4 ,! same result is rea*$ :5 ! ?ree trans=m]s ( a gr\p are jo9$ to ! l9e 9 me% or -fa%ion4 ,if ! ?ree trans=m]s ( a gr\p are jo9$ 9 /> or ,y-fa%ion1 ! coils ( ea* trans=m] are subject to fifty-eight p] c5t ( ! voltage betwe5 any two wires ( ! ?ree-phase l9e on :i* ! gr\p is connect$4 ,x is no long] ! practice to connect two or m trans=m]s 9 s]ies ei!r betwe5 two wires ( a two-phase or betwe5 two wires ( a ?ree-phase circuit1 because x is *eap] & m effici5t to use a s+le trans=m] 9 ea* ( ^! positions4 ,:]e v high voltage mu/ be develop$ or receiv$ ) a ?ree-phase sy/em1 ! /> or ,y-connection ( ea* gr\p ( ?ree trans=m]s has ! advantage ( a l[] /ra9 on ! insulation ( ea* trans=m] ?an t ) ! me% or -gr\p+4 ,?us if ! -gr\p+ is us$1 ! l9e pressure equals t ( ea* trans=m] coil1 b if ! ,y-gr\p+ is us$ ! l9e voltage is #a4gc times t ( ea* trans=m] coil4 ,at ! ,colgate p[]-h\se1 ! #gjj-kil[att trans=m]s are design$ = a maximum pressure ( #fj1jjj volts on ! ?ree-phase l9e :5 ,y-connect$1 s t ! correspond+ voltage is #cd1fge 9 _! second>y coils4 ,! prim>y coils ( ^! same trans=m]s are connect$ 9 me% or -=m & ea* coil op]ates at #b1cjj volts1 ! g5]ator pressure4 ,trans=m]s are 9 "s cases provid$ ) sev]al sets ( connections to _! coils s t !y may be op]at$ at widely diff]5t pressures4 ,?us1 9 ! ,colgate plant1 ea* trans=m] has taps br\ght out f its second>y coils s t x c be op]at$ at ei!r #bc1age1 #bh1ibe1 or #cd1fge1 ) #b1cjj volts at its prim>y coil4 ,correspond+ to ! ?ree voltages nam$ 9 ea* second>y coil are voltages ( #dj1jjj1 #ej1jjj1 & #fj1jjj on a ?ree-phase l9e connect$ ) ?ree ( ^! trans=m]s 9 ,y-fa%ion4 ,! me% or -connection is us$ betwe5 ! coils ( trans=m]s on "s transmission l9es ( v high voltage4 ,! #iej kil[att trans=m]s 9 ! sy/em betwe5 ,caon ,f]ry & ,butte illu/rate ?is practice1 be+ connect$ -fa%ion to ! #ej1jjj-volt l9e4 ,:5 trans=m]s t w op]ate at ! desir$ l9e voltage on -connection c be obta9$ at slight advance ov] ! co/ ( trans=m]s requir+ ,y-connections1 x is (t5 bett] practice to select ! =m]1 because ?is w enable an increase ( sev5ty-?ree p] c5t 9 ! voltage ( transmission to be made at any future "t by simply *ang+ to ,y-connections4 ,su* an increase ( voltage may become desirable because ( gr[+ loads or ext5sion ( transmission l9es4 ,an example ( ?is sort came up "s "t ago 9 connection ) ! transmission betwe5 ,ogd5 & ,salt ,lake ,city1 :i* 0 op]at+ at #af1jjj volts1 ?ree-phase1 ) ! high-pressure coils ( trans=m]s connect$ 9 -=m4 ,by *ang+ to ,y-connections ! l9e voltage 0 rais$ sev5ty-?ree p] c5t )\t increas+ ! /ra9 on trans=m] insulation4 ,9 "s cases x is desirable to *ange alt]nat+ curr5t f two-phase to ?ree-phase1 or vice v]sa1 = purposes ( transmission or di/ribution1 & ?is c readily be done by means ( /atic trans=m]s4 ,"o me?od (t5 employ$ to effect ?is result includes ! use ( two trans=m]s connect$ to opposite phases ( ! two-phase circuit4 ,! ?ree-phase coil ( "o ( ^! trans=m]s %\ld be design$ = ! desir$ ?ree-phase voltage1 & %\ld h a tap br\ght out f its c5tral po9t4 ,! ?ree-phase coil ( ! o!r trans=m] %\ld be design$ = #hg p] c5t ( ! desir$ ?ree-phase voltage4 ,"o end ( ! coil design$ = #hg p] c5t ( ! ?ree-phase voltage %\ld be connect$ to ! c5tre tap ( ! ?ree-phase coil 9 ! o!r trans=m]4 ,! o!r end ( ! #hg p] c5t coil goes to "o wire ( ! ?ree-phase circuit4 ,! o!r two wires ( ?is circuit %\ld be connect$1 respectively1 to ! outside end ( ! coil t has ! c5tral tap4 ,z a matt] ( illu/ration x may be requir$ to trans=m #ejj-volt1 two-phase curr5t f g5]ators1 to #bj1jjj-volt1 ?ree-phase curr5t = transmission4 ,two trans=m]s design$ = #ejj volts 9 _! prim>y coils are necess>y = ?is "w4 ,"o ( ^! trans=m]s %\ld h a second>y coil design$ = #bj1jjj volts1 s t ! ratio ( trans=mation is #bj1jjj #ejj or #dj to #a1 & a tap %\ld be br\ght out f ! c5tre ( ?is coil4 ,! o!r trans=m] %\ld h a second>y voltage ( #j4hg #bj1jjj #ag1djj1 s t its ratio ( trans=mation is #cd4h to #a4 ,^! two trans=m]s1 ) ! connections above indicat$1 w *ange ! #ejj-volt1 two-phase curr5t to #bj1jjj volts1 ?ree-phase4 ,at "o ( ! wat]-p[] /ations supply+ en]gy = use 9 ,h>t=d1 f\r trans=m]s ( #cjj kil[atts ea* *ange #ejj-volt1 two-phase curr5t f ! g5]ators to #aj1jjj-volt1 ?ree-phase1 = ! transmission l9e4 ,9 ! ,niag>a wat]-p[] /ation ! g5]ators deliv] two-phase curr5t at #b1bjj volts1 & #ige-kil[att trans=m]s are connect$ 9 pairs to *ange ! pressure to #bb1jjj volts1 ?ree-phase1 = transmission to ,buffalo4 ,a trans=m] is us$ 9 "s cases to raise ! voltage & comp5sate = ! loss 9 a transmission l9e4 ,= ?is purpose ! second>y ( a trans=m] giv+ ! numb] ( volts by :i* ! l9e pressure is to be increas$ is connect$ 9 s]ies ) ! l9e4 ,! prim>y w9d+ ( ?is trans=m] may be suppli$ f ! l9e boo/$ or f ano!r s\rce4 ,trans=m]s rang+ 9 capacity f #ajj to #a1jjj kil[atts ea*1 su* z are commonly us$ = transmission "w1 h effici5cies ( #if to #ih p] c5t at full loads1 :5 ( fir/-class con/ruction4 ,effici5cy increases sl[ly ) trans=m] capacity )9 ! limits nam$1 & #ih p] c5t c be fairly expect$ 9 only ! l>g] sizes4 ,9 any giv5 trans=m] ! effici5cy may be expect$ to fall a little1 say "o or two p] c5t1 betwe5 full load & half load1 & ano!r "o p] c5t betwe5 half load & qu>t] load4 ,^! figures = effici5cies at p>tial loads v>y some:at ) ! design & make ( trans=m]s4 ,9 g5]al1 x may be said t /ep-up or /ep-d[n trans=m]s w co/ approximately #g4ej p] kil[att capacity1 or ab\t "o-half ( ! l co/ ( l[-voltage dynamos4 ,if dynamos ( voltage suffici5tly high = ! transmission l9e c be _h at a figure bel[ ! comb9$ co/ ( l[-volt dynamos & rais+ trans=m]s1 x w usually pay to avoid ! latt] & develop ! l9e voltage 9 ! armature coils4 ,?is plan avoids ! loss 9 "o set ( trans=m]s4 ,,trans=m]s ,,9 ,,transmission ,,sy/ems4 ---------------------------------------- ------------------- ,trans- ,trans- ,g5]a- =m]s =m]s tors at at ,p[]- at ,sub- ,p[]- ,transmission ,sy/em4 /ations4 /ations4/ations4 ------------------------- ,no4 ,kw4 ,no4 ,kw4 ,no4 ,kw4 ,ea*4 ,ea*4 ,ea*4 ---------------------------------------- ---------------- ,caon ,f]ry to ,butte #ab #cbe ,a ,a 444 444 #f #iej #f #iej #aj #gej ,apple ,riv] to ,/4 ,paul 444 444 #f #cjj 444 444 #f #ejj #d #bjj #d #gej ,:ite ,riv] to ,dales #c #djj #c #cge #b #ejj ,f>m+ton ,riv] to ,h>t=d #d #cjj 444 444 #b #fjj ,ogd5 to ,salt ,lake ,b#i #bej 444 444 #e #gej ,colgate to ,oakl& 444 #gjj 444 444 #caabe #dbbej ,presumpscot ,riv] to ,portl& 444 444 #f #bjj 444 444 #c #aej #d #ejj #a #ahj #c #cjj ,f\r wat]-p[]s to ,man*e/] 444 444 #ba #bjj #a #dej #d #fej #aabjj ---------------------------------------- ---------------- ,a ,o!r trans=m]s at ,hel5a sub-/ations4 ,b ,"p ( en]gy di/ribut$ directly f g5]ators4 ,,*apt] ,,xi4 ,,swit*es1 ,,fuses1 ,,& ,,circuit-,,break]s4 ,electrical transmission has work$ a revolution 9 ! art ( swit*+4 ,z long z ! di/ances to be cov]$ by di/ribution l9es requir$ pressures ( only a few hundr$ volts1 ! swit* contacts = g5]ators & fe$]s c\ld well be expos$ 9 a r[ on ! surface ( v]tical m>ble slabs & sep>at$ f ea* o!r by di/ances ( only a few in*es4 ,^! swit*es 7 capable ( manual op]ation ev5 at times ( heavy ov]load )\t dang] ( p]sonal injury to ! op]ator or ( de/ructive arc+ betwe5 ! p>ts ( a s+le swit* or f "o swit* to ano!r ne>-by4 ,on ! back ( ^! m>ble slabs "o or m sets ( b>e bus-b>s c\ld be locat$ )\t mu* probability t an accid5tal contact betwe5 !m w\ld />t an arc capable ( de/roy+ ! entire swit*bo>d /ructure & %utt+ d[n ! /ation4 ,! rise ( electric pressures to ?\s&s & t5s ( ?\s&s ( volts 9 di/ribution & transmission sy/ems has va/ly increas$ ! difficulty ( safe & effective control ) op5-air swit*es4 ,! high] ! voltage ( ! circuit to be op]at$ "u load ! great] mu/ be ! di/ance betwe5 ! contact p>ts ( ea* swit* & also betwe5 adjac5t swit*es4 ,su* swit*es mu/ also be f>!r remov$ f ! op]ators z ! voltages ( _! circuits g up1 z a p]son _c safely /& v close to an electric arc ( sev]al feet or ev5 y>ds 9 l5g?4 ,9 ! ,we/1 :]e long transmissions are mo/ common1 long break-/ick swit*es h be5 mu* us$ ) high voltages4 ,^! swit*es dep5d on ! l5g? ( ! break to op5 ! circuit & on ! l5g? ( ! /ick t moves ! swit*-jaw or plug to insure ! safety ( ! op]ator4 ,:]e swit*es ( ?is sort are us$ x is highly important to h ample di/ances betwe5 ! contact po9ts ( ea* swit* & also betwe5 ! sev]al swit*es4 ,on circuits ( n m ?an #aj1jjj volts an arc z mu* z a y>d long w 9 "s cases foll[ ! op5+ swit* blade & hold on = sev]al seconds4 ,on ! #cc1jjj-volt transmission l9e at ,los ,angeles a peculi> =m ( swit* is us$ :i* makes a break betwe5 a pair ( curv$ wire horns t are t5 in*es ap>t at _! ne>e/ po9ts4 ,:5 ! contact betwe5 ^! horns is brok5 ! arc travels up betwe5 portions ( ! horns t curve ap>t & is ?us f9ally ruptur$4 ,besides ! v l>ge space requir$ = op5 swit*es on circuits ( #e1jjj to #aj1jjj volts or m1 !re is a fur!r objection t ! arcs develop$ by op5+ su* swit*es "u heavy loads rapidly de/roy ! contact p>ts & produce l>ge quantities ( metallic vapor t is objectionable 9 a c5tral /ation4 ,9 "s exp]im5ts p]=m$ at ,kalamazoo 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 p4 #djg7 ) op5-air swit*es ! voltages rang$ f #be1jjj to #dj1jjj4 ,! loads on circuits brok5 by ! swit*es 7 highly inductive & m\nt$ f #a1bjj to #a1cjj kilovolt-amp]es4 ,at #be1jjj volts ! arc produc$ by ! op5-air swit* held on = sev]al seconds4 ,at #dj1jjj volts ! arc foll[+ ! op5+ ( ?is swit* 0 ov] ?irty feet long1 & be+ out ( doors ne> ! pole l9e ! arc /ruck ! l9e wires & %ort-circuit$ ! sy/em4 ,x has be5 %[n t ! oscillations ( voltage occurr+ :5 a circuit "u heavy load is op5$ by an op5-air swit* may be v dang]\s to insulation 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 p4 #chc74 ,9 ! ,kalamazoo te/ ! oscillations ( ?is sort 7 report$ to h rea*$ two or ?ree times ! normal voltage ( ! sy/em :5 ! op5-air swit* 0 us$4 ,illu/ration3 ,,fig4 #ee4--;,connections betwe5 ,p[]-h\ses #a & #b at ,niag>a ,falls4 ,facts ( ! nature j outl9$ h l$ to ! developm5t ( oil swit*es4 ,! g5]al *>act]i/ic ( oil swit*es is t ! contact p>ts are imm]s$ 91 & ! break betwe5 ^! contacts takes place "u1 oil4 ,two types ( ! oil swit* are made1 "o hav+ all ( its contact p>ts 9 ! same ba? ( oil & ! o!r hav+ a sep>ate oil-ba? = ea* contact4 ,comp>$ ) ^? ( ! op5-air type1 oil swit*es effect a great sav+ ( space1 develop no expos$ arcs or metallic vapors1 cause little if any oscillation or rise ( voltage 9 an alt]nat+ circuit1 & c be dep5d$ on to op5 circuits ( any voltage & capacity n[ 9 use4 ,9 ! te/s above m5tion$ at ,kalamazoo1 a ?ree-phase oil swit* mak+ two breaks 9 ea* phase & ) all ! six contacts 9 a s+le oil-ba? 0 us$ to op5 circuits ( #be1jjj volts & #a1bjj to #a1cjj kilovolt-arcs ) satisfactory results4 ,at #dj1jjj volts1 h[ev]1 ?is type ( swit* spat fire & emitt$ smoke1 indicat+ t x 0 work+ ne> its ultimate capacity4 ,a ?ree-phase swit* ) ea* ( its six contacts 9 a sep>ate cyl9drical oil-*amb] 0 us$ to op5 ! #dj1jjj-volt #a1cjj kilovolt-arc circuit at ,kalamazoo ) p]fect success ev5 "u conditions ( %ort-circuit & )\t ! appe>ance ( fire or smoke at ! swit*4 ,! ?ree-phase swit* us$ 9 ! te/s at ,kalamazoo & hav+ ea* ( its contacts 9 a sep>ate oil-*amb] 0 simil> 9 con/ruction to ! swit*es us$ 9 ! ,metropolitan & ,manhattan railway /ations 9 ,new ,york ,city4 ,9 ea* ( ^! swit*es ! two leads ( ea* phase t]m9ate 9 two upright brass cyl9d]s4 ,^! cyl9d]s h fibre l9+s to prev5t side-jump+ ( ! arcs :5 ! swit* is op5$1 & ea* cyl9d] is fill$ ) oil4 ,into ! two brass cyl9d]s ( ea* phase dips a -%ap$ contact piece ?r\gh insulat+ bu%+s1 & ! ends ( ?is contact piece fit into t]m9als at ! bottom ( ! oil pots4 ,a wood5 rod jo9s ! c5tre or upp] "p ( ! -contact piece1 & ! ?ree rods ( a ?ree-phase swit* pass up ?r\gh ! swit* comp>tm5t to ! op]at+ me*anism outside4 ,! six brass cyl9d]s & _! ?ree -contact pieces are usually m\nt$ on a swit* cell built entirely ( brickwork & /one slabs4 ,= a ?ree-phase swit* ! brick & /one cell has ?ree entirely sep>ate comp>tm5ts1 & ea* comp>tm5t conta9s ! two brass cyl9d]s t =m ! t]m9als ( a s+le phase4 ,on top ( & outside ! cell ! me*anism = mov+ ! wood5 swit* rods is m\nt$4 ,9 ! ,metropolitan /ation1 :]e ! voltage is #f1jjj1 ! v]tical movem5t ( ! -%ap$ contact piece ) its rod is twelve in*es4 ,at ! ,manhattan /ation1 :]e ! op]at+ voltage is #ab1jjj1 ! v]tical movem5t ( ! -contacts 9 op5+ a swit* is sev5te5 in*es4 ,! total break 9 ea* phase 9 a swit* at ! ,metropolitan /ation is ?us tw5ty-f\r in*es1 or f\r in*es p] #a1jjj volts1 & ! total break p] phase 9 swit*es at ! ,manhattan /ation is ?irty-f\r in*es1 or #b4ff in*es p] #a1jjj volts total pressure4 ,oil swit*es are n[ v g5]ally employ$ on alt]nat+ circuits t op]ate at #b1jjj volts or m = purposes ( g5]al di/ribution4 ,on circuits ( mod]ate voltage l t j nam$1 & ev5 high]1 x is common practice to use oil swit*es t h only a s+le res]voir ( oil ea*1 ! entire six contacts 9 ! case ( a ?ree-phase swit* be+ imm]s$ 9 ?is s+le res]voir4 ,su* swit*es are usually op]at$ directly by h& & are locat$ on ! backs ( or close to ! slate or m>ble bo>ds on :i* ! h&les t actuate ! swit* me*anism are locat$4 ,a good example ( ?is sort ( "w may be se5 at ! sub-/ation 9 ,man*e/]1 ,n4 ,h41 :]e en]gy f f\r wat]-p[] /ations is deliv]$ ov] sev5 transmission l9es & !n di/ribut$ by an ev5 l>g] numb] ( local circuits at #b1jjj volts ?ree-phase4 ,at ! ,g>v9's ,falls /ation1 "o ( ! wat]-p[] plants t deliv]s en]gy to ! sub-/ation 9 ,man*e/]1 ! g5]ators op]ate at #ab1jjj volts ?ree-phase1 & ^! g5]ators connect directly ) ! bus-b>s ?r\gh h&-op]at$ oil swit*es on ! back ( ! m>ble swit*bo>d4 ,^! la/-nam$ swit*es1 l ^? at ! ,man*e/] sub-/ation1 h all ! contacts ( ea* 9 a s+le res]voir ( oil4 ,) v high voltages1 :]e only a few hundr$ kil[atts are conc]n$1 & also ) p[]s runn+ into ?\s&s ( kil[atts at z l[ a pressure z #b1jjj volts1 x is v desirable to remove ev5 oil swit*es f ! swit*bo>d & ! vic9ity ( ! bus-b>s4 ,great p[]s z well z v high voltages n only increase ! elem5t ( p]sonal dang] to an att5dant :o mu/ /& close to a swit* :ile op]at+ x1 b also r5d] ! damage to o!r app>atus t may result f any failure ( or %ort-circuit 9 a swit* mu* m s]i\s4 ,illu/ration3 ,,fig4 #ef4--,wire-room ,back ( ,swit*bo>d 9 ,p[]-/ation on ,fr5* ,broad ,riv]1 ,nor? ,c>ol9a4 ,z soon z ! swit*es are remov$ to a di/ance f ! op]at+ bo>d ! necessity = "s me?od ( p[] control becomes evid5t1 s9ce ! op]ator at ! swit*bo>d %\ld be able to make or break connections ( any "p ( ! app>atus quickly4 ,! necessity = ! removal ( swit*es = v l>ge p[]s to a di/ance f ! op]at+ bo>ds & = ! application ( me*anical p[] to make & break connections 0 met be=e ! developm5t ( oil swit*es4 ,?us at ! fir/ ,niag>a 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 p4 #dhi7 p[]-h\se1 9 #ahic1 ! swit*es = ! #c1gej-kil[att1 #b1bjj-volt g5]ators1 ?\gh ( ! op5-air type1 7 locat$ 9 a special swit* comp>tm5t erect$ 9 ! g5]ator room & ov] a cable subway at "s di/ance f ! op]at+ bo>d4 ,^! swit*es 7 actuat$ ?r\gh compress$-air cyl9d]s into :i* air 0 admitt$ by ! movem5t ( lev]s ne> ! swit*bo>d4 ,evid5tly a swit* ( ?is capacity--#a1jjj amp]es p] pole & #b1bjj volts1 two-phase--c\ld n well be op]at$ by h&-p[] :]ev] locat$1 because ( ! l>ge ef=t requir$4 ,9 ! second g5]at+ /ation at ,niag>a ,falls oil swit*es simil> to ^? us$ at ! ,manhattan ,elevat$ ,railway plant 9 ,new ,york1 b two-phase1 7 employ$4 ,ea* ( ^! oil swit*es at ,niag>a ,falls has a capacity ( #e1jjj horse-p[]1 l ! previ\s op5-air swit*es1 & is electrically actuat$4 ,illu/ration3 ,,fig4 #eg4--,section ?r\gh ,cable ,subway "u ,oil ,swit*es 9 ,niag>a ,p[]-h\se ,no4 #b4 ,9 ^! electrically op]at$ oil swit*es a small motor is locat$ on top ( ! brick cell t conta9s ! contact p>ts1 & ?is motor releases & compresses spr+s t op5 & close ! swit*4 ,:ile x is n desirable to employ op5-air swit*es to op5 circuits ( sev]al ?\s& or ev5 hundr$s ( kil[atts at voltages ( #b1jjj or m1 x is nev]!less possible to d s4 ,?is is %[n by ! exp]i5ce ( ! fir/ ,niag>a ,falls /ation1 :]e ! #b1bjj-volt two-phase swit*es are report$ to h op5$ repeat$ly curr5ts ( m ?an #fjj amp]es p] phase )\t injuri\s sp>k+4 ,! great rise ( voltage t 0 %[n by ! exp]im5ts at ,kalamazoo to foll[ ! op5+ ( a simple op5-air swit* 0 avoid$ at ! fir/ ,niag>a swit*es by a simple exp$i5t4 ,9 ^! #e1jjj horse-p[] op5-air swit*es a %unt ( high resi/ance 0 s connect$ betwe5 ea* pair ( contacts t ! blades & jaws t c>ri$ ! ma9 body ( ! curr5t nev] completely op5$ ! circuit4 ,:5 ! ma9 jaws ( "o ( ^! swit*es 7 op5$ ! %unt resi/ance cont9u$ 9 circuit until subsequ5tly brok5 at auxili>y t]m9als4 ,t no excessive rise ( voltage took place :5 "o ( ^! swit*es 0 op5 0 %[n by connect+ two %>p t]m9als 9 p>allel ) ! swit* & by adju/+ ^! t]m9als to a c]ta9 di/ance ap>t4 ,_h ! voltage ris5 on op5+ ! swit* above ! pr$et]m9$ am\nt !re w\ld h be5 an arc =m$ by a sp>k jump+ ! di/ance betwe5 ! po9t$ t]m9als4 ,illu/ration3 ,,fig4 #eh4--,s*5ectady ,swit*-h\se on ,spi] ,falls ,l9e4 ,illu/ration3 ,,fig4 #ei4--,second-floor ,plan ( ,s>atoga ,swit*-h\se on ,spi] ,falls ,l9e4 ,safety & reliability ( op]ation at high voltages1 say ( #e1jjj or m1 require t ea* elem5t ( ! equipm5t be s isolat$ z well z insulat$ f e o!r elem5t t ! failure or ev5 de/ruction ( "o elem5t w n s]i\sly endang] ! o!rs4 ,) ?is end 9 view ! cables f ea* g5]ator to its swit* %\ld be laid 9 a conduit ( brick or concrete t conta9s no o!r cables4 ,! brick or /one comp>tm5t = ea* phase ( ea* swit* %\ld be s sub/antial t ! contacts ( t phase may arc to de/ruction )\t injury to ! contacts ( ano!r phase4 ,bus-b>s1 l swit*es1 %\ld be remov$ f ! op]at+ swit*bo>d1 because an arc betwe5 !m might de/roy o!r app>atus !reon1 & ev5 ! bo>d itself4 ,x is n en\gh to remove bus-b>s f ! swit*bo>d :]e v high voltages are to be controll$1 b ea* b> %\ld be locat$ 9 a sep>ate brick comp>tm5t s t an arc _c be />t$ by accid5tal contact betwe5 two or m ( ! b>s4 ,x is conv5i5t to h ! brick & /one comp>tm5ts = bus-b>s built horizontally "o above ! o!r4 ,! top & bottom ( ea* comp>tm5t may conv5i5tly be =m$ ( /one slabs ) brick pi]s on "o side & a cont9u\s brick wall on ! o!r to hold ! /one slabs 9 position4 ,connections to ! bus-b>s %\ld pass ?r\gh ! cont9u\s brick wall t =ms :at may be t]m$ ! back ( ! comp>tm5ts4 ,to close ! op5+s betwe5 ! brick pi]s at ! front ( ! comp>tm5ts movable slabs ( /one may be us$4 ,fe$]s pass+ away f ! bus-b>s1 l dynamo cables runn+ to ^! b>s1 %\ld n be gr\p$ close toge!r 9 a s+le comp>tm5t1 b ea* cable or circuit %\ld be laid 9 a sep>ate firepro( conduit to ! po9t :]e x passes out ( ! /ation4 ,illu/ration3 ,,fig4 #fj4--;,gr\nd ,floor ( ,s>atoga ,swit*-h\se4 ,! folly ( gr\p+ a l>ge numb] ( fe$]s t transmit great p[]s toge!r 9 a s+le combu/ible comp>tm5t 0 well illu/rat$ by ! accid5t t de/roy$ ! cables t connect$ ! fir/ ,niag>a p[]-/ation ) ! trans=m]-h\se on ,janu>y #bi?1 #aijc4 ,on ! ev5+ ( t day lightn+ %ort-circuit$ "o ( ! cables 9 ! %ort bridge t connects ,no4 #a /ation ) ! trans=m]-h\se1 & all ! cables 9 ?is bridge1 supply+ local consum]s z well z railways & light+ 9 ,buffalo1 7 de/roy$4 ,?is bridge conta9$ probably m ?an ?irty-six cables1 z t numb] ( new cables 0 put 9 position )9 tw5ty-f\r h\rs aft] ! accid5t1 & ^! cables1 cov]$ ) inflammable insulation1 7 close toge!r4 ,! result 0 n only ! loss ( ! cables1 b also ! damage to p[] us]s4 ,if ^! cables _h be5 locat$ 9 sep>ate fire-pro( conduits1 x is highly probable t only ! "o directly affect$ by lightn+ w\ld h be5 de/roy$4 ,! brick & /one comp>tm5ts = bus-b>s may be locat$ 9 ! basem5t und]nea? ! swit*bo>d1 z at ! ,portsm\? /ation ( ! ,new ,hamp%ire ,traction ,company1 or at any o!r place 9 a /ation :]e !y are suffici5tly remov$ f ! o!r app>atus4 ,9 p[]-h\se ,no4 #b at ,niag>a ,falls a cable subway b5ea? ! floor level runs ! entire l5g?1 p>allel ) ! r[ ( g5]ators 7,a4 ,i4 ,e4 ,e41 vol4 xix41 p4 #ecg74 ,9 ?is subway1 :i* is ?irte5 feet n9e & ?ree-qu>t] in*es wide & t5 feet six in*es high1 ! two /ructures = bus-b> comp>tm5ts are locat$4 ,ea* ( ^! /ructures measures ab\t #f4f feet high & #a4h feet wide1 & conta9s f\r bus-b> comp>tm5ts4 ,9 ea* comp>tm5t is a s+le b>1 & ! f\r b>s =m two sets = two-phase work+4 ,above ! bus-b> comp>tm5ts & ris+ f ! floor level are ! oil swit*es4 ,a space ov] ! cable subway midway ( its l5g? & betwe5 ! two gr\ps ( oil swit*es is occupi$ by ! swit*bo>d gall]y :i* is rais$ to "s elevation above ! floor & c>ries elev5 g5]ator1 tw5ty-two fe$]1 two int]connect+1 & "o excit] panels4 ,9 p[]-h\se ,no4 #a ! bus-b>s are locat$ 9 a common space above ! #e1jjj horse-p[] op5-air swit*es already m5tion$1 & ea* b> has an insulation ( vulcaniz$ rubb] cov]$ ) braid & outside ( ?is a wrapp+ ( tw9e4 ,( c\rse2 an insulation ( ?is sort w\ld am\nt to no?+ if by any accid5t an arc 7 />t$ betwe5 ! b>s4 ,:]e ea* bus-b> is locat$ 9 a sep>ate firepro( comp>tm5t1 z at ,niag>a p[]-h\se ,no4 #b1 ! application ( insulation directly to ea* b> is nei!r necess>y nor desirable4 ,consequ5tly ! g5]al practice :]e ea* b> has its own firepro( comp>tm5t is to con/ruct ! b>s ( b>e copp] rods4 ,) ma9 swit*es = g5]ators & fe$]s remov$ f ! op]at+ bo>d & actuat$ by electric motors or magnets1 ! small swit*es at ! bo>d ) :i* ! op]ator is directly conc]n$ mu/ ( c\rse control ^! magnets or motors4 ,! small swit*es at ! op]at+ bo>d are call$ relay swit*es1 & ! curr5t 9 ! circuits op5$ & clos$ by ^! swit*es & us$ to op]ate ! magnets or motors ( ! oil swit*es may be conv5i5tly obta9$ f a /orage batt]y or f "o ( ! excit+ dynamos4 ,probably ! be/ arrangem5t ( ! relay swit*es is 9 connection ) dummy bus-b>s on ! face ( ! swit*bo>d1 s t ! connections on ! face ( ! bo>d con/itute at all times a diagram ( ! actual connections ( ! g5]ator & fe$] circuits4 ,x is also desirable = quick & correct *anges 9 ! connections ( ! ma9 app>atus t all ! relay swit*es & in/rum5ts necess>y = ! control ( any "o g5]ator or any "o fe$] be br\ght toge!r on a s+le panel ( ! swit*bo>d4 ,if ?is plan is foll[$1 ! op]ator at any "t w h be=e him on a s+le panel all ( ! swit*es & in/rum5ts involv$ 9 ! connections !n to be made1 & ! *ance = mi/akes is ?us r$uc$ to a m9imum4 ,! plan j outl9$ 0 t adopt$ at ! ,niag>a p[] plant ,no4 #b1 :]e a sep>ate panel is provid$ = ea* ( elev5 g5]ators & ea* ( tw5ty-two fe$]s4 ,on ea* ( ! elev5 g5]ator panels !re are two selector relay swit*es1 "o g5]ator relay swit*1 & "o relay g5]ator field swit*4 ,on ea* ( ! tw5ty-two fe$] panels !re are two relay selector swit*es4 ,! relay swit*es on ! two int]connect+ panels s]ve to make connections betwe5 ! two gr\ps ( five & six g5]ators respectively 9 p[]-h\se ,no4 #b & ! t5 g5]ators ( p[]-h\se ,no4 #a4 ,on ea* panel !re are relay indicators to %[ :e!r ! oil swit*es t c>ry ! ma9 curr5t respond to ! movem5ts ( _! relay swit*es4 ,:]e ! electric g5]ators op]ate at ! maximum voltage ( ! sy/em1 z at ,g>v9's ,falls & 9 ! p[]-h\se ( ! ,manhattan ,elevat$ ,railway1 !re may be said to be only "o g5]al plan ( connections possible4 ,t is1 ! g5]ators mu/ connect directly ) ! ma9 bus-b>s at ! voltage ( ! sy/em1 & ! fe$]s or transmission l9es mu/ also connect to ^! same b>s4 ,( c\rse !re may be sev]al sets ( bus-b>s = diff]5t circuits or classes ( "w1 b ?is does n *ange ! g5]al plan ( ?r\gh connections f g5]ators to l9es4 ,s1 too1 ! arrangem5t ( swit*es is subject to v>iations1 z by plac+ two swit*es 9 s]ies ) ea* o!r 9 ea* dynamo or fe$] cable1 or by connect+ a gr\p ( fe$]s ?r\gh _! sev]al swit*es to a p>ticul> set ( bus-b>s & !n supply+ ?is set ( b>s f ! g5]ator bus-b>s ?r\gh a s+le swit*4 ,illu/ration3 ,,fig4 #fa4--,swit*bo>d ,wir+1 ,gl5s ,falls ,sub-/ation on ,spi] ,falls ,l9e4 ,:]e ! voltage ( transmission is obta9$ by ! use ( /ep-up trans=m]s1 ! connections ( ^! trans=m]s may be su* z to require ne>ly all swit*+ to be done on ei!r ! high- or l[-t5sion circuits4 ,! m g5]al practice 0 =m]ly to d all swit*+ 9 ! g5]ator circuits & on ! l[-t5sion side ( trans=m]s1 except 9 ! connection & disconnection ( trans=m]s & transmission l9es ) ! high-t5sion bus-b>s1 :5 n 9 op]ation4 ,:]e g5]ators op]ate at ! maximum voltage ( ! sy/em only two ma9 gr\ps ( swit*es are necess>y1 "o gr\p connect+ g5]ators to bus-b>s1 & ! o!r gr\p connect+ bus-b>s to ! transmission l9es4 ,z soon z /ep-up trans=m]s are introduc$ ! numb] ( swit* gr\ps mu/ be increas$ to f\r if ! usual me?od ( connection is foll[$1 & !re mu/ be bo? a high voltage & a l[ voltage set ( bus-b>s4 ,t is1 "o set ( swit*es mu/ connect g5]ators ) l[-t5sion bus-b>s1 ano!r gr\p mu/ connect l[-t5sion b>s ) ! prim>y coils ( trans=m]s1 a ?ird gr\p jo9s ! second>y coils ( trans=m]s ) ! high-t5sion b>s1 & ! f\r? gr\p ( swit*es jo9s ! transmission l9es to ! high-t5sion bus-b>s4 ,swit*es connect+ ! second>y coils ( /ep-up trans=m]s to ! high-t5sion bus-b>s1 & also ! transmission l9es to ^! same b>s1 h (t5 be5 ( ! simple op5-air type ) %ort knife-blade con/ruction4 ,^! swit*es h be5 us$ to disconnect ! second>y coils ( trans=m]s & also ! transmission l9es f ! high-t5sion bus-b>s :5 no curr5t 0 fl[+1 & swit*es ( ! simple knife-blade con/ruction ) %ort breaks c\ld ( c\rse be us$ = no o!r purpose4 ,) swit*es ( ?is sort on ! high-t5sion side ( app>atus ! practice is to d all swit*+ ( l9e circuits on ! l[-t5sion side4 ,x is possible to avoid "s ( ?is multiplication ( swit*es if ea* g5]ator ) its trans=m]s is treat$ = swit*+ purposes z a unit & ! swit*+ = ?is unit is done on ! second>y or high-voltage side ( ! /ep-up trans=m]s4 ,! adoption ( ?is plan1 ( c\rse1 implies ! use ( swit*es t are compet5t to break ! second>y circuit ( any gr\p ( trans=m]s "u ov]load conditions & at ! maximum voltage ( ! sy/em1 b oil swit*es z n[ made are compet5t to meet ?is requirem5t4 ,:5 all swit*+ ( live circuits is conf9$ to ^? ( high voltage !re is also ! incid5tal advantage t heavy contact p>ts c>ry+ v l>ge curr5ts are avoid$ 9 ! op]at+ swit*es4 ,:]e ea* g5]ator is connect$ directly to its own gr\p ( trans=m]s ! second>y coils ( ^! trans=m]s w pass ?r\gh oil swit*es to high-t5sion bus-b>s1 & ! use ( l[-t5sion bus-b>s may be avoid$4 ,f ^! high-t5sion bus-b>s ! transmission l9es w pass ?r\gh oil swit*es1 s t on ?is plan !re are only two sets ( oil swit*es1 namely1 ^? connect+ ! second>y coils ( trans=m]s to ! high-t5sion bus-b>s1 & ^? connect+ ! transmission l9es to ! same b>s4 ,ea* gr\p ( two or ?ree trans=m]s1 accord+ z two or ?ree are us$ ) ea* g5]ator1 %\ld be connect$ to its g5]ator ?r\gh %ort-break1 op5-air knife swit*es = conv5i5ce 9 disconnect+ & *ang+ trans=m]s t are n 9 op]ation1 b ^! swit*es are n int5d$ or requir$ to op5 ! circuit ( ! g5]ators & prim>y coils :5 9 op]ation4 ,illu/ration3 ,,fig4 #fb4--;,di/ribut+ ,swit*bo>d1 ,c5tral ,sub-/ation1 ,montreal4 ,a plan simil> to t j outl9$ 0 foll[$ at ! /ation ( ! ,indep5d5t ,electric ,light & ,p[] ,company1 ,san ,francisco1 :]e ea* ( ! #eej-volt g5]ators is ord9>ily connect$ directly to ! prim>y coils ( two trans=m]s t *ange ! curr5t f two-phase to ?ree-phase & !n deliv] x ?r\gh oil swit*es to ! high-t5sion bus-b>s at #aa1jjj volts4 ,to ^! bus-b>s ! #aa1jjj-volt fe$]s = five sub-/ations are connect$ ?r\gh swit*es4 ,at ?is /ation !re is a set ( #eej-volt bus-b>s to :i* any ( ! g5]ators may be connect$1 b to :i* no g5]ator is connect$ 9 ord9>y op]ation4 ,! g5]ators alone h swit*es connect+ ) ^! b>s4 ,:5 x is desirable to op]ate any p>ticul> g5]ator on "s pair ( trans=m]s o!r ?an its own1 t g5]ator is disconnect$ f its own trans=m]s & connect$ to ! #eej-volt bus-b>s4 ,! g5]ator ^: trans=m]s are to be op]at$ by ! g5]ator be=e m5tion$ next has its swit* connect$ to ! #eej-volt bus-b>s1 :ile ! bru%es ( ! contact r+s ( ! =m] g5]ator are rais$4 ,z ! leads f ea* g5]ator to its two swit*es are p]man5tly jo9$1 ! swit*+ op]ations j nam$ connect ! trans=m]s ( "o g5]ator ) ! o!r g5]ator t has its swit* clos$ on ! #eej-volt b>s4 ,illu/ration3 ,,fig4 #fc4--,swit*bo>d at ,*ambly ,p[]-/ation4 ,:]e x is desir$ t a s+le res]ve trans=m] may be readily sub/itut$ = any "o ( a numb] ( trans=m]s 9 regul> use1 ! connections to ea* ( ^! latt] trans=m]s may be provid$ ) d\ble-pole d\ble-?r[ knife swit*es on bo? ! prim>y & second>y sides1 s t :5 ^! swit*es are ?r[n "o way at any trans=m] 9 regul> use ! res]ve trans=m] w be connect$ 9 its place4 ,fuses & automatic circuit-break]s alike are int5d$ to break connections )\t ! int]v5tion ( human ag5cy "u c]ta9 pr$et]m9$ conditions4 ,9 ! fuse ! heat g5]at$ by a c]ta9 curr5t is suffici5t to melt or vaporize a %ort l5g? ( special conductor4 ,9 ! circuit-break] a c]ta9 curr5t gives a magnet or motor suffici5t /r5g? to ov]come ! pressure ( a spr+1 & contact pieces ?r\gh :i* ! curr5t is pass+ are pull$ ap>t4 ,! prim>y object ( bo? ! fuse & ! circuit-break] is ?us to op5 connections & /op ! fl[ ( en]gy :5 m ?an a c]ta9 curr5t passes4 ,:5 any curr5t passes ?r\gh a circuit 9 ! rev]se ( its regul> direction ! circuit-break] c be arrang$ to break ! connections1 ?\gh ! fuse _c4 ,a fuse mu/ c>ry ! curr5t at :i* x is design$ to melt dur+ "s seconds be=e en\gh heat is develop$ to de/roy x1 & ! exact numb] ( seconds = any p>ticul> case is made a little unc]ta9 by ! possibility ( loose connections at ! fuse tips :i* develop additional heat & also by ! heat-conduct+ p[] ( its connect+ t]m9als4 ,a circuit-break] may be set s z to op5 its connections 9 "o or m seconds aft] a c]ta9 curr5t beg9s to fl[4 ,:5 connections are brok5 by a fuse ! molt5 or vaporiz$ metal =ms a pa? t an arc may easily foll[4 ,a circuit-break] ) its contacts "u oil (f]s a mu* small] opportunity ?an a fuse = ! ma9t5ance ( an arc4 ,^! qualities ( fuses & circuit-break]s =m ! basis ( _! g5]al availability & comp>ative advantages 9 transmission circuits4 ,mu* v>iation exi/s 9 practice z to ! use ( fuses & circuit-break]s on transmission circuits4 ,"o view (t5 foll[$ is t fuses & circuit-break]s %\ld be entirely omitt$ f ! g5]ator & transmission l9es4 ,! argum5t 9 favor ( ?is practice is t tempor>y %ort circuits due to birds t fly aga9/ ! l9es or to /icks & loose wires t are ?r[n onto !m w int]rupt all or a l>ge "p ( ! transmission s]vice if fuses or circuit-break]s t op]ate in/antly are employ$4 ,on ! o!r h&1 x may be said t if fuses & circuit-break]s are omitt$ f ! g5]ator & transmission circuits a la/+ %ort circuit w make x necess>y to %ut d[n an entire plant 9 "s cases until x c be remov$4 ,electric transmission at high voltages became important be=e magnetic circuit-break]s compet5t to op5 ov]load$ circuits at su* voltages 7 develop$4 ,consequ5tly ! e>ly "q 0 :e!r a transmission l9e & ! g5]ators t f$ x %\ld be provid$ ) fuses or be solidly connect$ f g5]ators to ! di/ribution circuits ( sub-/ations4 ,! orig9al t5d5cy 0 /rong to use fuses 9 accord ) ! practice at l[ voltages4 ,! great importance ( cont9u\s s]vice f transmission sy/ems & ! _m int]ruptions caus$ by tempor>y %ort circuits :]e fuses 7 us$ l$ to _! ab&onm5t 9 "s cases4 ,an example ( ?is sort may be se5 at ! fir/ ,niag>a /ation4 ,9 #ahic1 :5 ?is /ation 0 equipp$1 no magnetic circuit-break] 0 available = circuits ( ei!r #aa1jjj or #b1bjj volts1 c>ry+ curr5ts ( sev]al ?\s& horse-p[]1 & fuses 7 employ$ 9 l9es at bo? ^! pressures 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 pp4 #die1 #dig74 ,! fuses adopt$ 9 ?is case 7 ! same = bo? ! #b1bjj & ! #aa1jjj-volt l9es & 7 ( ! explosive type4 ,ea* complete fuse consi/$ ( two lignum-vit blocks t 7 h+$ toge!r at "o end & 7 secur$ :5 clos$ at ! o!r4 ,9 ^! blocks ?ree p>allel grooves = fuses 7 cut & 9 ea* groove a /rip ( alum9um 0 laid & connect$ to suitable t]m9als at ea* end4 ,v5ts 7 provid$ = ! grooves 9 :i* ! alum9um /rips 7 plac$ s t ! exp&+ gas :5 a fuse 0 bl[n w\ld escape4 ,:5 ^! fuse blocks 7 new & ! blocks ( lignum vit made tight jo9ts ! metallic vapor produc$ :5 a fuse 0 bl[n 0 =c$ out at ! v5ts & ! connections ( ! l9e 7 ?us brok54 ,aft] a "t1 h[ev]1 :5 ! jo9ts betwe5 ! blocks 7 no long] tight because ( %r9kage1 ! exp&+ gas ( ! fuse w\ld rea* ! t]m9als & an arc w\ld cont9ue aft] ! fuse _h bl[n4 ,^! alum9um fuses1 :i* 7 adopt$ ab\t #ahic1 7 ab&on$ at ! ,niag>a plant 9 #ahih4 ,s9ce ?is lat] date ! #b1bjj-volt fe$]s f ! ,no4 #a p[]-h\se to ! local consum]s h _h no fuses at ! p[]-h\se1 nor h circuit-break]s be5 in/all$ !re 9 ! place ( ! fuses t 7 remov$4 ,at ! l>ge manufactur+ plants suppli$ ?r\gh ^! local ,niag>a fe$]s1 ! fe$]s =m]ly t]m9at$ 9 fuses1 b ^! h s9ce be5 displac$ by circuit-break]s4 ,9 ! second ,niag>a p[]-/ation1 complet$ 9 #aijb1 ! local #b1bjj-volt fe$]s are provid$ ) circuit-break]s1 b no fuses4 ,betwe5 ! g5]ators & bus-b>s ( ! fir/ ,niag>a plant ! circuits 7 provid$ ) nei!r fuses nor automatic circuit-break]s1 & ?is practice cont9ues !re to ! pres5t "t4 ,besides ! alum9um fuses 9 ! #aa1jjj-volt transmission l9e at ! fir/ ,niag>a /ation1 !re 7 lead fuses 9 ! #b1bjj-volt prim>y circuits ( ! /ep-up trans=m]s t suppli$ ^! l9es4 ,at ! o!r end ( ^! l9es1 9 ! ,buffalo sub-/ation1 ano!r set ( alum9um fuses 0 ins]t$ be=e connection 0 made ) ! /ep-d[n trans=m]s4 ,betwe5 ! second>y coils ( ^! trans=m]s & ! #eej-volt conv]t]s !re 7 no fuses1 b ^! conv]t]s 7 connect$ to ! railway bus-b>s ?r\gh direct curr5t circuit-break]s4 ,^! lead fuses1 :i* conta9$ mu* m metal ?an ^? ( alum9um1 :5 bl[n set up arcs t la/$ until p[] 0 cut (f by op5+ a swit*1 & usually de/roy$ _! t]m9als4 ,an ef=t 0 made to s adju/ ! sizes ( ! fuses 9 ?is transmission sy/em t 9 case ( a %ort circuit 9 di/ribution l9es at ,buffalo only ! fuses 9 ! sub-/ation w\ld be bl[n1 leav+ ^? at ,niag>a entire4 ,?is plan did n prove effective1 h[ev]1 & a sev]e ov]load on ! di/ribution l9es 9 ,buffalo w\ld bl[ out fuses cle> back to ! g5]ator bus-b>s at ! ,niag>a /ation4 ,9 ord] to accompli% ! op5+ ( ov]load$ circuits ) great] c]ta9ty1 to delay su* op5+ :]e ! ov]load might be ( only a mom5t>y nature1 & to conf9e ! op5 circuit to ! l9es :]e ! ov]load exi/$1 automatic circuit-break]s 7 sub/itut$ = ! fuses nam$ 9 ! ,niag>a & ,buffalo transmission sy/em4 ,?is sy/em 0 also *ang$ f #aa1jjj to #bb1jjj volts on ! transmission l9es1 ?us r5d]+ ! requirem5ts z to circuit-op5+ devices m sev]e4 ,^! circuit-break]s 7 fitt$ ) "t-limit atta*m5ts s t any break] c\ld be set to op5 at ! end ( any numb] ( seconds aft] ! curr5t fl[+ ?r\gh x rea*$ a c]ta9 am\nt4 ,a circuit-break] ) su* a "t-limit atta*m5t w n op5 until ! "t = :i* x is set1 aft] ! amp]es fl[+ ?r\gh x rea* a c]ta9 figure1 has elaps$1 no matt] h[ great ! curr5t may be4 ,moreov]1 if ! ov]load is remov$ f a l9e be=e ! numb] ( seconds = :i* its "t-limit circuit-break] is set h elaps$1 ! circuit-break] resets itself automatically & does n op5 ! connections4 ,if a circuit-break] is set to op5 a l9e aft] an int]val ( say ?ree seconds f ! "t :5 its curr5t rea*es ! limit1 ! l9e w n be op5$ by a m]e mom5t>y ov]load su* z w\ld bl[ out a fuse4 ,by sett+ ! "t-limit relays ( circuit-break]s 9 transmission l9es to actuate ! op5+ me*anism aft] ?ree seconds f ! "t t an ov]load comes on1 & !n leav+ ! break]s on di/ribution l9es to op]ate )\t a "t-limit1 x seems t ! op5+ ( break]s on ! di/ribution l9es %\ld free ! sy/em f an ov]load !re be=e ! break]s on ! transmission l9es h "t to act4 ,su* a result is v desirable 9 ord] t ! entire s]vice ( a transmission sy/em may n be int]rupt$ e "t !re is a fault or %ort circuit on "o ( its di/ribution l9es4 ,?is plan 0 foll[$ 9 ! ,niag>a & ,buffalo sy/em4 ,9 ! #bb1jjj-volt l9es at ! ,niag>a /ation ! "t relays 7 set to actuate ! break]s aft] ?ree seconds1 at ! t]m9al h\se 9 ,buffalo1 :]e ! trans=m]s /ep d[n f #bb1jjj to #aa1jjj volts1 ! circuit-break]s 9 ! #aa1jjj volt l9es to sub-/ations _h _! relays set to op5 9 "o second4 ,f9ally ! circuit-break]s 9 ! di/ribution l9es f ! sev]al sub-/ations 7 left to op]ate )\t any "t limit4 ,by ^! means x 0 expect$ t a %ort circuit 9 "o ( ! di/ribution circuits f a sub-/ation w\ld n cause ! connections ( ! und]gr\nd cable betwe5 t sub-/ation & ! t]m9al h\se to be brok51 because ( ! in/ant action ( ! circuit-break] at ! sub-/ation4 ,fur!rmore1 x 0 expect$ t a %ort circuit 9 "o ( ! und]gr\nd cables betwe5 ! t]m9al h\se & a sub-/ation w\ld be disconnect$ f ! transmission l9e at t h\se & w\ld n cause ! circuit-break]s at ! ,niag>a /ation to op]ate4 ,x is report$ t ! =ego+ arrangem5t ( circuit-break]s ) "t relays fail$ ( its object because ! break]s did n cle> _! circuits quick en\gh & t ! "t-limit atta*m5ts on ! #bb1jjj & #aa1jjj volt l9es are no long] 9 use 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 p4 #ejj74 ,z ! circuits "u consid]ation convey ?\s&s ( horse-p[] at #aa1jjj & #bb1jjj volts x may be t "t-limit devices ) circuit-break]s w\ld give good results "u less exact+ conditions4 ,"t-limit relays are p]haps an important aid t[>d reliable op]ation ( transmission sy/ems1 b !y are subject to ! objection t no matt] h[ great ! ov]load !y w n op5 ! circuit until ! "t = :i* !y are set has run4 ,9 ! case ( a %ort circuit ! "t-limit relay may lead to a prolong$ drop 9 voltage ?r\gh\t ! sy/em1 :i* is v undesirable = ! light+ s]vice & also all[s all syn*ron\s app>atus to fall out ( /ep4 ,) a m]e mom5t>y drop 9 voltage ! in]tia ( ! rotat+ p>ts ( syn*ron\s app>atus w keep !m 9 /ep4 ,= ^! reasons x is desirable to h circuit-break]s t w act imm$iately to op5 a l9e on :i* !re is a %ort circuit or v great ov]load1 b w op5 ! l9e only aft] an int]val ( "o or m seconds :5 ! ov]load is n ( a v extreme nature4 ,?is action on ! "p ( circuit-break]s at ! second ,niag>a p[]-/ation 0 obta9$ by ! atta*m5t ( a da%-pot to ! tripp+ plung] ( ea* circuit-break] 7,a4 ,i4 ,e4 ,e41 vol4 xviii41 p4 #edc74 ,) mod]ate ov]loads ( a v tempor>y nature ?is da%-pot s ret>ds ! action ( a tripp+ plung] t ! circuit-break] does n op54 ,:5 a %ort circuit or great ov]load comes onto a l9e ! pull on ! tripp+ plung] or ! circuit-break] on t l9e is s great t ! resi/ance ( ! da%-pot to ! movem5t is ov]come at once & ! l9e is disconnect$ f ! rema9d] ( ! sy/em4 ,! fact t a circuit-break] may be design$ to op5 ! l9e :i* x connects1 :5ev] ! direction f :i* ! fl[ ( en]gy takes place is rev]s$1 is tak5 advantage ( at "s sub-/ations to gu>d aga9/ a fl[ ( en]gy f a sub-/ation back t[>d ! g5]at+ /ation4 ,by ?is means a fl[ ( en]gy f a sub-/ation to a %ort circuit 9 "o ( ! l9es or cables connect+ x ) ! g5]at+ plant is prev5t$4 ,,*apt] ,,xii4 ,,regulation ,,( ,,transmitt$ ,,p[]4 ,regulation ( voltage at inc&esc5t lamps is a s]i\s problem 9 ! di/ribution ( electrically transmitt$ en]gy4 ,good regulation %\ld n all[ ! pressure at inc&esc5t lamps rat$ at #aaj to #abj volts to v>y m ?an "o volt above or bel[ ! normal4 ,electric motor s]vice is mu* less exact+ z to con/ancy ( voltage1 & ! pressure at motor t]m9als may sometimes be v>i$ z mu* z t5 p] c5t )\t mat]ial objection on ! "p ( us]s4 ,a mix$ s]vice to ^! ?ree classes ( app>atus mu/ (t5 be provid$ :]e transmitt$ en]gy is us$1 & ! limitations z to v>iations at inc&esc5t lamps are ?us ! ones t mu/ control ! regulation ( pressure4 ,transmission sy/ems may be broadly divid$ into ^? t h no sub-/ations & mu/ !re=e d all regulation at ! g5]at+ plant1 & ^? t d h "o or m sub-/ations s t regulation ( voltage may be c>ri$ out at bo? ends ( ! transmission l9e4 ,illu/ration3 ,,fig4 #fd4--;,arc-light+ ,swit*bo>d at ,c5tral ,sub-/ation1 ,montreal4 ,z a rule1 a sub-/ation ) an op]ator 9 att5dance is highly desirable betwe5 transmission & di/ribution l9es1 & ?is is ! plan g5]ally foll[$ at important c5tres ( electrical supply1 ev5 ?\gh ! transmission is a %ort "o4 ,"o example ( ?is sort may be not$ at ,spr+field1 ,mass41 :]e en]gy = electrical supply is transmitt$ f two wat]-p[] plants on ! ,*icopee ,riv] only ab\t f\r & a half & six miles1 respectively1 f ! sub-/ation 9 ! bus9ess c5tre ( ! city4 ,! voltage ( transmission = two-phase curr5t 9 ?is case is #f1jjj1 & is r$uc$ to ab\t #b1djj volts at ! sub-/ation = ! g5]al di/ribution ( light & p[]4 ,a simil> in/ance may be se5 at ,concord1 ,n4 ,h41 :]e electrical en]gy at bo? #b1ejj & #aj1jjj volts is deliv]$ to a sub-/ation 9 ! bus9ess section f a wat]-p[] plant at ,sewall's ,falls1 on ! ,m]rimac ,riv]1 f\r & "o-half miles di/ant4 ,f ?is sub-/ation ! curr5t is di/ribut$ at ab\t #b1ejj volts = ! supply ( lamps & motors4 ,a sub-/ation 0 f\nd desirable at ,concord = purposes ( regulation be=e ! voltage ( transmission 0 rais$ above t ( di/ribution4 ,subsequ5tly1 :5 ! load increas$1 ! voltage ( #aj1jjj 0 adopt$ on a "p ( ! transmission circuit 9 ord] to avoid an increase 9 ! size ( _! conductors4 ,illu/ration3 ,,fig4 #fe4--;,area ( ,electrical ,di/ribution at ,montreal4 ,illu/ration3 ,,fig4 #ff4 ,illu/ration3 ,,fig4 #fg4 ,illu/ration3 ,,fig4 #fh4 ,9 "s in/ances1 h[ev]1 transmission & di/ribution l9es are jo9$ )\t ! int]v5tion ( a sub-/ation1 :]e regulation ( voltage c be accompli%$1 ?\gh ?is practice has little to recomm5d x aside f ! sav+s 9 fir/ co/ ( in/allation & subsequ5t co/ ( op]ation4 ,^! sav+s are m app>5t ?an real if fairly con/ant pressure is to be ma9ta9$ at ! lamps1 because :at is ga9$ by ! omission ( sub-/ations w be (fset1 9 "p at lea/1 by additional outlays on ! l9es if good regulation is to be ma9ta9$4 ,?is fact may be illu/rat$ by ref]5ce to ,figs4 #ff1 #fg1 & #fh1 9 ea* ( :i* ,d repres5ts a g5]at+ /ation & ,a1 ,b1 & ,c t[ns or cities :]e en]gy f ! /ation is to be di/ribut$4 ,9 ! case ( ea* figure x is assum$ t ! di/ance betwe5 ! g5]at+ /ation & ea* ( ! cities or t[ns is su* t di/ribut+ l9es ) a loss (1 say1 n m ?an two p] c5t 9 voltage at full load _c be provid$ betwe5 ! g5]at+ /ation & ea* city or t[n because ( ! co/ ( conductors4 ,?is be+ s1 "o or m c5tres ( di/ribution mu/ be locat$ 9 ea* t[n1 & ! transmission l9es mu/ jo9 ! di/ribution l9es at ^! c5tres ei!r on poles or 9 sub-/ations4 ,if sev]al ( ^! t[ns are 9 ! same g5]al direction f ! g5]at+ plant s z to be rea*$ by ! same transmission l9e1 z ,a1 ,b1 & ,c 9 ,fig4 #ff1 ?is "o l9e w be all t is necess>y ) a sub-/ation 9 ea* t[n4 ,:]e sub-/ations are n employ$ a sep>ate transmission circuit mu/ be provid$ betwe5 ! g5]at+ plant & ea* t[n = reasons t w appe> pres5tly4 ,! p]c5tage ( voltage v>iation 9 a transmission l9e "u *ang+ loads w be frequ5tly f five to t51 & is ?us f> beyond ! all[able v>iations at inc&esc5t lamps4 ,to give good light+ s]vice ! c5tre ( di/ribution1 :]e ! transmission l9e jo9s ! di/ribution circuits1 mu/ be ma9ta9$ at v ne>ly con/ant voltage if no sub-/ation is locat$ !re4 ,regulation at a g5]at+ /ation w comp5sate = ! *ang+ loss ( pressure 9 a l9e "u v>y+ loads s z to ma9ta9 a ne>ly con/ant voltage at any "o po9t !reon4 ,no plan ( /ation regulation1 h[ev]1 c ma9ta9 con/ant voltages at sev]al po9ts on ! same transmission l9e :5 !re is a v>y+ load at ea*4 ,! result is t ev5 ?\gh ! sev]al t[ns s]v$ are 9 ! same g5]al direction f ! g5]at+ /ation1 z 9 ,fig4 #fg1 yet ea* t[n %\ld h its sep>ate transmission l9e :]e no sub-/ations 9 ! t[ns are provid$4 ,9 ! case illu/rat$ by ,fig4 #fh1 :]e ! t[ns s]v$ are 9 v diff]5t directions f ! g5]at+ /ation1 !re %\ld be a sep>ate transmission l9e to ea*1 reg>dless ( :e!r !re is a sub-/ation or only a c5tre ( di/ribution !re4 ,ev5 9 ! case illu/rat$ by ,fig4 #fh1 z 9 ea* ( ! o!rs1 !re is a l>ge sav+ effect$ 9 ! co/ ( di/ribution l9es by ! employm5t ( a sub-/ation at ! po9t :]e ^! l9es jo9 ! transmission circuit1 provid$ t ! v>iation ( pressure at lamp t]m9als is to be kept )9 "o volt ei!r way f ! /&>d4 ,) ! v>iations ( loads ! loss ( pressure 9 ! di/ribution l9es w range f z]o to its maximum am\nt & ! connect$ lamps w be subject$ to ! *ange ( voltage repres5t$ by ?is total loss1 unless ! di/ribution />t f a sub-/ation :]e ! loss 9 di/ribution l9es c be comp5sat$ = by regulation4 ,to give good s]vice ! di/ribution l9es %\ld be limit$ to a loss ( "o p] c5t at full load if !re is no sub-/ation :]e !y jo9 transmission l9es4 ,) opportunity = regulation at a sub-/ation ! maximum loss 9 di/ribution l9es may easily be d\bl$1 ?us r$uc+ _! weight by "o-half 9 comp>ison ) t requir$ :]e !re is no sub-/ation4 ,ano!r advantage ( connect+ transmission & di/ribution l9es 9 a sub-/ation1 :]e regulation ( voltage c be _h1 lies 9 ! fact t x is practically impossible to ma9ta9 an absolutely con/ant pressure miles f a g5]at+ plant at ! end ( a transmission l9e t is c>ry+ a mix$ & v>y+ load4 ,a result is t )\t ! int]v5tion ( regulation at a sub-/ation x is almo/ impossible to give good light+ s]vice ov] a long transmission l9e4 ,fur!rmore1 ! labor ( regulation at a g5]at+ /ation is mu* increas$ :]e !re are no sub-/ations1 because x mu/ be mu* m frequ5t & accurate4 ,! abs5ce ( sub-/ations f a transmission sy/em ?us implies m transmission circuits1 heavi] di/ribution circuits1 m labor at ! g5]at+ plant1 & a poor quality ( light+ s]vice4 ,:]e /ation>y motors =m ! great bulk ( ! load on a transmission sy/em1 & good light+ s]vice is ( small importance1 x may be well to omit sub-/ations at "s c5tres ( di/ribution4 ,?is is a condition t sometimes exi/s 9 ! ,rocky ,m\nta9 region :]e ! ma9 consum]s ( p[] along a transmission l9e may be m9es or works = ! r$uction ( ores4 ,an example ( ?is sort exi/s 9 ! sy/em ( ! ,telluride ,p[] ,transmission ,company1 9 ,utah1 :i* ext5ds f ,provo ,caon1 on ! riv] ( ! same "n1 entirely ar\nd ,utah ,lake by way ( ,m]cur1 ,eureka1 & ,provo1 & back to ! p[]-h\se 9 ,provo ,caon1 a cont9u\s circuit ( #aje miles4 ,! transmission voltage on ?is l9e is #dj1jjj1 & at int]vals :]e !re are di/ribut+ po9ts ! voltage is r$uc$ to ab\t #e1jjj by trans=m]s on poles1 & )\t ! aid ( regulation at sub-/ations 9 "s cases4 ,! p[] ?us transmitt$ is l>gely us$ 9 m9es & smelt]s = ! op]ation ( motors1 b also = "s comm]cial light+4 ,regulation at g5]at+ /ations ( ! voltage on transmission l9es may be accompli%$ by ! same me?ods :e!r !re are sub-/ations at c5tres ( di/ribution or n4 ,9 any su* regulation ! aim is to ma9ta9 a c]ta9 voltage at "s p>ticul> po9t on ! transmission l9e1 usually its end1 :]e ! di/ribution circuits are connect$4 ,if m ?an "o po9t ( di/ribution exi/s on ! same transmission l9e1 ! regulation at ! g5]at+ plant mu/ be design$ to ma9ta9 ! desir$ pressure at only "o ( ^! po9ts1 leav+ regulation at ! o!rs to be accompli%$ by local means4 ,"o me?od ( regulation consi/s 9 ! ov]comp\nd+ ( ea* g5]ator s t ! voltage at its t]m9als w rise at a c]ta9 rate z its load increases4 ,if a g5]ator & transmission l9e are s design$ t ! rise ( voltage at ! g5]ator t]m9als j corresponds ) ! loss ( voltage on ! l9e :5 ! output ( t g5]ator alone passes ov] x to "s p>ticul> po9t1 !n ! pressure at t po9t may be held ne>ly con/ant = all loads if no en]gy is drawn f ! l9e else:]e4 ,^! sev]al conditions necess>y to make regulation by ! comp\nd+ ( g5]ators effective c seldom be met 9 practice4 ,if a v>y+ numb] ( g5]ators mu/ "w on ! same transmission l9e1 or if v>y+ loads mu/ be suppli$ at diff]5t po9ts along ! l9e1 no comp\nd w9d+ ( g5]ators w suffice to ma9ta9 a con/ant voltage at any po9t on ! l9e t is di/ant f ! p[]-/ation4 ,= ^! reasons ! comp\nd w9d+ ( g5]ators is ( m9or importance s f> z ! regulation ( voltage on transmission l9es is conc]n$1 & on l>ge alt]nators is n g5]ally attempt$4 ,an example may be not$ on ! #c1gej-kil[att g5]ators at ,niag>a ,falls1 :]e ! s+le magnet w9d+ receives curr5t f ! excit]s only4 ,a mu* m effective & g5]ally adopt$ me?od ( regulation ( voltage at ! g5]at+ plants ( transmission sy/ems is bas$ on ! action ( an att5dant :o v>ies ! curr5t 9 ! magnet coils ( ea* g5]ator s z to raise or l[] its voltage z desir$4 ,! regulation mu/ be = "s "o po9t on ! transmission l9e1 & ! att5dant at ! g5]at+ plant may "k ! voltage at t po9t ei!r by means ( a pair ( pressure wires run back f t po9t to a voltmet] at ! g5]at+ plant1 by a met] t indicates ! voltage at ! po9t 9 "q accord+ to ! curr5t on ! l9e1 or by telephone connection ) a sub-/ation at ! po9t :]e ! con/ant voltage is to be ma9ta9$4 ,pressure wires are a reliable means ( indicat+ 9 ! g5]at+ /ation ! voltage at a po9t ( di/ribution on ! l9e1 b ! erection ( ^! wires is q an exp5se 9 a long transmission1 & 9 su* cases !y are only occasionally us$4 ,ow+ to inductive effects & to v>iable p[]-factors ! amp]es indicat$ on a l9e c>ry+ alt]nat+ curr5t are f> f a c]ta9 guide z to ! drop 9 voltage betwe5 ! g5]at+ /ation & ! di/ant po9t4 ,9 long transmissions1 telephone communication betwe5 ! g5]at+ plant & ! sub-/ations is ! mo/ g5]al way 9 :i* necess>y *anges to ma9ta9 con/ant voltage at sub-/ations are br\ght to ! att5tion ( ! att5dant 9 ! g5]at+ plant4 ,few1 if any1 ext5sive transmission sy/ems n[ op]ate )\t telephone connection betwe5 a g5]at+ plant & all ( its sub-/ations1 or betwe5 a s+le sub-/ation & ! sev]al g5]at+ plants t may fe$ into x4 ,?us1 ! g5]at+ plant at ,spi] ,falls1 on ! ,hudson ,riv]1 w be connect$ by telephone ) sub-/ations at ,s*5ectady1 ,albany1 ,troy1 & "s half-doz5 small] places4 ,on ! o!r h&1 ! s+le sub-/ation 9 ,man*e/]1 ,n4 ,h41 t receives ! en]gy f f\r wat]-p[] plants has a direct telephone l9e to ea*4 ,:]e two or m transmission l9es f ! same p[]-/ation are op]at$ f ! same set ( bus-b>s ! voltage at a di/ant po9t on ea* l9e _c be held con/ant by *anges ( pressure on ^! bus-b>s4 ,"o g5]ator only may be connect$ to ea* transmission l9e & be regulat$ = ! loss on t l9e1 b ?is loses ! advantages ( multiple op]ation4 ,ano!r plan is to connect a regulator 9 ea* transmission l9e be=e x goes f ! g5]at+ plant4 ,"o type ( regulator = ?is purpose consi/s ( a trans=m] ) its second>y coil divid$ into a numb] ( sections & ! ends ( ^! sections br\ght out to a s]ies ( contact segm5ts4 ,! prim>y coil ( ?is trans=m] may be suppli$ ) curr5t f ! bus-b>s & ! second>y coil is !n connect$ 9 s]ies ) ! l9e to be regulat$1 s t ! second>y voltage is add$ to or subtract$ f t ( ! ma9 circuit4 ,a movable contact arm on ! segm5ts to :i* ! sections ( ! second>y coil are connect$ makes x possible to v>y ! second>y voltage by *ang+ ! numb] ( ^! sections 9 circuit4 ,9 ano!r trans=m] us$ = regulat+ purposes ! prim>y coil is connect$ to ! bus-b>s z be=e & ! movable second>y coil is put 9 s]ies ) ! l9e to be regulat$4 ,! regulation is accompli%$ 9 ?is case by *ang+ ! position ( ! second>y relative to t ( ! prim>y coil & ?us rais+ or l[]+ ! second>y voltage4 ,bo? ( ^! regulators require h& adju/m5t1 & ! att5dant may employ ! telephone1 pressure wires1 or ! comp5sat+ voltmet] above m5tion$1 to det]m9e ! voltage at ! c5tre ( di/ribution4 ,! voltage indicat$ by ?is s-call$ 8comp5sator0 is t at ! g5]at+ /ation m9us a c]ta9 am\nt :i* v>ies ) ! curr5t fl[+ 9 ! l9e to be regulat$4 ,! voltmet] coil ( ! comp5sator is connect$ 9 s]ies ) ! second>y coils ( two trans=m]s1 :i* coils "w aga9/ ea* o!r4 ,"o trans=m] has its second>y coil arrang$ to indicate ! full /ation voltage1 & ! o!r second>y coil is actuat$ by a prim>y coil t c>ries ! full curr5t ( ! regulat$ l9e4 ,by a s]ies ( contacts ! effect ( ?is la/-nam$ coil c be v>i$ to correspond ) ! numb] ( volts t are to be lo/ at full load betwe5 ! g5]at+ /ation & ! po9t on ! transmission l9e at :i* ! voltage is to be held con/ant4 ,if !re is no inductive drop on ! transmission l9e1 or if ?is drop is ( kn[n & con/ant am\nt1 ! comp5sator may give ! actual voltage at ! po9t = :i* ! regulation is design$4 ,automatic regulators are us$ 9 "s g5]at+ /ations to ma9ta9 a con/ant voltage ei!r at ! g5]at+ t]m9als or at "s di/ant di/ribut+ po9t on a l9e op]at$ by a s+le g5]ator4 ,^! regulators may op]ate rheo/ats t are 9 s]ies ) ! magnet w9d+s ( ! g5]ators to be regulat$1 & raise or l[] ! g5]ator voltage by v>y+ ! excit+ curr5t 9 ^! w9d+s4 ,^! regulators are mu* m effective to ma9ta9 con/ant voltage at g5]at+ /ations ?an at ! di/ribut+ end ( long transmission l9es ) v>iable p[]-factors4 ,9 spite ( ! comp\nd w9d+ ( g5]ators1 ( automatic regulators = ! excit+ curr5ts 9 _! magnet coils1 & ( regulat+ trans=m]s 9 ! transmission circuits1 h&-adju/m5t ( rheo/ats 9 s]ies ) ! magnet coils ( g5]ators rema9s ! mo/ g5]ally us$ at ! g5]at+ /ations ( long transmission sy/ems4 ,automatic regulators at ! ends ( transmission l9es 9 sub-/ations are n[ be+ introduc$1 & may prove v desirable4 ,illu/ration3 ,,fig4 #fi4--,motor-g5]ators 9 ,%aw9igan ,sub-/ation at ,montreal4 ,! m exact+ & f9al "w ( regulation 9 transmission sy/ems is usually done at ! sub-/ations4 ,aft] a ne>ly con/ant voltage is deliv]$ at ! high-pressure coils ( /ep-d[n trans=m]s 9 a sub-/ation1 !re rema9s ! v>y+ losses 9 ^! trans=m]s1 9 motor-g5]ators or conv]t]s1 9 di/ribution l9es & 9 s]vice trans=m]s1 to be comp5sat$ =4 ,9 g5]al1 ?ree or f\r sorts ( loads mu/ be provid$ =1 namely1 arc or inc&esc5t lamps = /reet light+ on s]ies circuits1 usually ( #d1jjj to #aj1jjj volts4 ,arc & inc&esc5t lamps on con/ant-pressure circuits ( #b1jjj to #b1ejj volts = comm]cial light+1 direct-curr5t /ation>y motors on con/ant-pressure circuits ( ab\t #ejj volts1 & alt]nat+ motors :i* may be s]v$ at ei!r #b1ejj or #ejj volts accord+ to _! sizes & locations4 ,to ^! loads may be add$ t ( /reet-c> motors ( #ejj volts1 direct curr5t4 ,bo? ! /ation>y & ! /reet-c> motors1 b m especially ! latt]1 by _! *anges ( load give rise to l>ge & rapid fluctuations ( voltage on ! di/ribution l9es to :i* !y are connect$4 ,! problem ( regulation ) comb9$ lamp & motor loads is n1 !re=e1 s mu* to ma9ta9 a ne>ly con/ant voltage at ! motors z to protect ! lamps f ! fluctuations ( voltage :i* ! motors set up4 ,illu/ration3 ,,fig4 #gj4--,"o ( ! #a1jfe-kil[att ,motor-g5]ators 9 ! ,%aw9igan ,sub-/ation at ,montreal4 ,= /reet-c> motors us+ direct curr5t at ab\t #ejj volts1 ! sub-/ation equipm5t includes ei!r /ep-d[n trans=m]s & conv]t]s or motor-g5]ators ) or )\t trans=m]s4 ,x is ! practice 9 "s cases :]e bo? light+ & /reet-railway s]vice are drawn f ! same transmission sy/em to keep ^! two k9ds ( s]vice entirely sep>ate1 devot+ indep5d5t g5]ators & transmission l9es1 z well z indep5d5t trans=m]s & conv]t]s or motor-g5]ators1 to ! /reet-c> "w4 ,?is is done 9 ! transmission sy/em c5tr+ at ,man*e/]1 ,n4 ,h41 9 :i* ea* "o ( ! f\r wat]-p[] plants1 z well z ! sub-/ation1 has a d\ble set ( bus-b>s on ! swit*bo>d2 & f ea* wat]-p[] plant to ! sub-/ation !re are two transmission circuits4 ,9 op]ation1 "o set ( g5]ators1 bus-b>s1 transmission circuits1 & trans=m]s supply conv]t]s or motor-g5]ators = ! /reet-c> motors2 & ano!r set ( g5]ators1 bus-b>s1 transmission circuits1 & trans=m]s are devot$ to light+ & /ation>y motors 9 ?is sy/em4 ,:]e /reet-c> motors draw _! en]gy f ! same g5]ators & transmission l9es t supply comm]cial inc&esc5t lamps1 "s means mu/ be adopt$ to protect ! light+ circuits f ! fluctuations ( voltage set up by ! v>y+ /reet-c> loads4 ,"o way to accompli% ?is purpose is to op]ate ! light+ circuits ) g5]ators driv5 by syn*ron\s motors 9 ! sub-/ations4 ,^! g5]ators may1 ( c\rse1 be ( ei!r direct or alt]nat+ type & ( any desir$ voltage4 ,! syn*ron\s motors driv+ ^! g5]ators take _! curr5t f ! transmission l9e ei!r ) or )\t ! int]v5tion ( /ep-d[n trans=m]s4 ,by ?is use ( syn*ron\s motors ! light+ circuits escape fluctuations ( voltage correspond+ to ^? on ! transmission l9e1 because syn*ron\s motors ma9ta9 con/ant spe$s indep5d5tly ( ! voltage ( ! circuits to :i* !y are connect$4 ,?is plan 0 foll[$ at ,buffalo1 :]e ! /reet-c> sy/em & ! light+ s]vice are op]at$ ) en]gy f ! ,niag>a ,falls /ations ov] ! same transmission l9e4 ,9 "o ( ! sub-/ations at ,buffalo1 bo? #b1bjj-volt1 two-phase alt]nators1 & #aej-volt cont9u\s-curr5t g5]ators = light+ s]vice1 are driv5 by syn*ron\s motors connect$ to ! ,niag>a transmission l9e ?r\gh trans=m]s4 ,at o!r sub-/ations 9 ,buffalo1 ! #ejj-volt cont9u\s curr5t = /reet-c> motors is obta9$ f ! same transmission sy/em ?r\gh trans=m]s & conv]t]s4 ,ano!r solution ( ! problem ( voltage regulation :]e /reet-railway & comm]cial light+ s]vice are to be drawn f ! same transmission l9e is f\nd 9 ! op]ation ( #ejj-volt cont9u\s-curr5t g5]ators 9 ! sub-/ations by syn*ron\s motors f$ f ! l9e ei!r directly or ?r\gh trans=m]s4 ,?is plan has be5 adopt$ 9 ! transmission sy/em ( ! ,bo/on ,edison ,company1 :i* ext5ds to a numb] ( cities & t[ns )9 a radius ( tw5ty-five miles4 ,! sub-/ations at ,natick & ,woburn 9 ?is sy/em1 :]e !re are /reet-railway z well z light+ loads1 conta9 #ejj-volt cont9u\s-curr5t g5]ators driv5 by syn*ron\s motors connect$ directly to ! ?ree-phase transmission l9es4 ,9 a case l ?is ! syn*ron\s motors ma9ta9 _! spe$ irrespective ( ! voltage on ! l9e & ?us t5d to hold t voltage /eady 9 spite ( ! v>iable losses due to fluctuat+ loads4 ,/ation>y motors %\ld n z a rule be op]at$ f ! same di/ribution l9es t supply inc&esc5t lamps1 especially 9 sizes above "o horse-p[]1 & ?is is ! bett] practice4 ,motor circuits ( ab\t #b1djj volts & two- or ?ree-phase1 alt]nat+1 or #ejj volts1 alt]nat+ or direct curr5t1 may be suppli$ at a sub-/ation ei!r by trans=m]s alone 9 ! fir/ case or by trans=m]s & conv]t]s 9 ! second4 ,9 ei!r case no especial provision is usually necess>y = ! regulation ( con/ant pressure on ! motor circuits4 ,illu/ration3 ,,fig4 #ga4--a1ajj-kil[att1 #b1cjj-volt1 ,?ree-phase1 #cj-;cycle1 ,syn*ron\s ,motor at ,sub-/ation ( ,%aw9igan ,l9e 9 ,montreal4 ,9 "s transmission sy/ems ! di/ribution circuits = /ation>y motors are n f$ by ! same transmission l9es t c>ry ! light+ load1 b draw _! en]gy f l9es t d no o!r "w4 ,?is practice is c]ta9ly desirable1 z x frees ! light+ circuits f all fluctuations ( voltage due to l9e losses ) *ang+ motor loads4 ,examples ( ?is sort may be se5 at ,spr+field1 ,mass41 & ,portl& & ,lewi/on1 ,me41 9 ea* ( :i* ! load ( /ation>y motors is op]at$ ov] indep5d5t transmission z well z di/ribution l9es4 ,9 transmission sy/ems s]ies arc & inc&esc5t lamps = /reet light+ are commonly op]at$ ei!r by direct-curr5t arc dynamos or by con/ant-curr5t trans=m]s or con/ant-pressure trans=m]s ) automatic regulators at ! sub-/ations4 ,! arc dynamos are driv5 by ei!r induction or syn*ron\s motors suppli$ directly f ! transmission l9e or ?r\gh trans=m]s4 ,z ! arc dynamos regulate automatically = con/ant curr5t no fur!r regulation is requir$4 ,if ! s]ies arc & inc&esc5t lamps are to be suppli$ ) alt]nat+ curr5t1 ! con/ant-curr5t trans=m] or ! con/ant-curr5t regulator come into use4 ,?is type ( trans=m] & regulator alike dep5d = _! regulat+ effect on ! movem5t ( a second>y coil on a trans=m] core 9 su* a way t ! curr5t 9 ?is coil1 :i* is 9 s]ies ) ! lamps1 is held ne>ly con/ant4 ,su* con/ant-curr5t trans=m]s & regulators are usually suppli$ f ! transmission l9e ?r\gh regul> con/ant-pressure trans=m]s1 & !y hold _! curr5ts suffici5tly con/ant = ! purposes ( _! use4 ,! ma9 problem ( regulat+ ?us comes back to ! #bej- or #b1bjj-volt1 con/ant-pressure circuits = inc&esc5t light+1 suppli$ f transmission l9es ?r\gh trans=m]s or motor g5]ators or bo? at ! sub-/ation4 ,= ?is regulation "o ( ! mo/ reliable in/rum5ts is ! h& ( a skilful att5dant1 guid$ by voltmet]s connect$ ) pressure wires f m9or c5tres ( di/ribution1 & adju/+ ! regulat+ trans=m]s above m5tion$1 or o!r regulat+ devices4 ,,*apt] ,,xiii4 ,,gu>d ,,wires ,,& ,,lightn+ ,,arre/]s4 ,lightn+ 9 its v>i\s =ms is ! greate/ dang] to :i* transmission sy/ems are expos$1 & x attacks _! mo/ vuln]able po9t1 t is1 insulation4 ,! less] dang] z to lightn+ is t x w puncture ! l9e insulators & %att] or set fire to ! poles4 ,! great] dang] is t ! lightn+ dis*>ge w pass along ! transmission wires to /ations & sub-/ations & w !re break d[n ! insulation ( g5]ators1 motors1 or trans=m]s4 ,damage by lightn+ may be prev5t$ 9 ei!r ( two ways1 t is1 by %ield+ ! transmission l9e s completely t no =m ( lightn+ *>ge or dis*>ge c rea* x1 or by provid+ s easy a pa? f l9e conductors to e>? t lightn+ rea*+ ^! conductors w foll[ ! int5d$ pa? in/ead ( any o!r4 ,9 practice ! %ield+ effect is s\ght by gr\nd$ gu>d wires1 & ! easy pa? = dis*>ge takes ! =m ( lightn+ arre/]s1 b nei!r ( ^! devices is entirely effective4 ,a]ial transmission l9es are expos$ to direct dis*>ges ( lightn+1 to electromagnetic *>ges due to lightn+ dis*>ges ne> by1 & to electro/atic *>ges t are br\ght ab\t by contact ) or induction f electrically *>g$ bodies ( air4 ,x is evid5tly impracticable to provide a %ield t w free ov]head l9es f all ^! influ5ces4 ,to cut (f bo? electro/atic & electromagnetic induction f a wire & also to free x f a possible direct dis*>ge ( lightn+1 x seems t x w\ld at lea/ be necess>y completely to incase ! wire ) a ?ick body ( conduct+ mat]ial4 ,?is condition is approximat$ :5 an electric circuit is entirely b5ea? ! surface ( ! gr\nd1 b w\ld be h>d to ma9ta9 ) b>e ov]head wires4 ,x seems1 h[ev]1 t gr\nd$ gu>d wires ne> to & p>allel ) long a]ial circuits %\ld t5d to dis*>ge any high electro/atic pressures exi/+ 9 ! surr\nd+ air1 & mat]ially to r$uce ! probability t a direct dis*>ge ( lightn+ w *oose ! highly insulat$ circuits = its pa? to e>?4 ,lightn+ arre/]s may conduct induc$ & direct lightn+ dis*>ges to e>?1 )\t damage to transmission l9es1 s t bo? arre/]s & gu>d wires may logically be us$ 9 ! same sy/em4 ,wide diff]5ces ( op9ion exi/ z to ! g5]al desirability ( gr\nd$ gu>d wires on transmission l9es1 bo? because ( _! und\bt$ disadvantages & because ! degree ( protection t !y af=d is unc]ta94 ,x seems1 h[ev]1 t ! defects ( gu>d wires dep5d 9 l>ge degree on ! k9d ( wire us$ = ! purpose1 & ! me?od ( its erection4 ,galvaniz$ iron wire ) b>bs e few in*es has be5 m g5]ally us$ = gu>d wires along transmission l9es ?an any o!r sort4 ,sometimes a s+le gu>d wire ( ?is sort has be5 run on a pole l9e c>ry+ transmission circuits1 & ! m common location ( ?is s+le wire is on ! tops ( ! poles4 ,9 o!r cases two gu>d wires h be5 us$ on ! same pole l9e1 "o ( ^! wires be+ locat$ at ea* end ( ! highe/ cross-arm & outside ( ! p[] wires4 ,besides ^! gu>d wires at ! ends ( ! top cross-arms ( a pole l9e1 a ?ird wire has 9 "s sy/ems be5 add$ to ! tops ( ! poles4 ,^! gu>d wires h sometimes be5 secur$ to ! poles & cross-arms by iron /aples driv5 ov] ! wire & into ! wood1 & 9 o!r cases ! gu>d wires are m\nt$ on small glass insulators4 ,mu* v>iation 9 practice also exi/s z to ! gr\nd connections ( gu>d wires1 su* connections be+ made at e pole 9 "s sy/ems1 & mu* less frequ5tly 9 "s o!rs4 ,) all ^! diff]5ces 9 ! practical application ( gu>d wires x is n /range t op9ions z to _! utility d n agree4 ,fur!r reason = diff]5ces ( op9ion z to ! practical value ( gu>d wires exi/s 9 ! fact t 9 "s p>ts ( ! c\ntry ! dang]s f lightn+ are l>gely ^? ( ! /atic & inductive sort1 t are mo/ effectively provid$ = by lightn+ arre/]s1 :ile 9 o!r p>ts ( ! c\ntry direct lightn+ /rokes are ! greate/ m5ace to transmission sy/ems4 ,at ! pres5t "t1 k ( ! laws gov]n+ ! v>i\s manife/ations ( en]gy t are kn[n "u ! g5]al head ( lightn+ is imp]fect1 & ! mo/ reliable rules = ! use ( gu>d wires along transmission l9es are ^? d]iv$ f practical exp]i5ce4 ,a case :]e a gu>d wire did n prove effective z a protection aga9/ lightn+ is t ( ! ,san ,miguel ,consolidat$ ,gold ,m9+ ,company1 ( ,telluride1 ,col41 ^: ?ree transmission l9es ran f ! wat]-p[] plant to po9ts f ?ree to t5 miles di/ant1 z describ$ 9 ,a4 ,i4 ,e4 ,e41 vol4 xi41 p4 #ccg1 & foll[+ pages4 ,?is transmission op]at$ at #c1jjj volts1 s+le-phase1 alt]nat+1 & ! pole l9es ran ov] ! m\nta9s at elevations ( #h1hjj to #ab1jjj feet above sea-level1 pass+ across b>e ridges & tracts ( magnetic mat]ial4 ,x 0 /at$ t ! c\ntry ov] :i* ! circuits ran is s dry & rocky t x 0 practically impossible to secure good gr\nd connections along ! l9e1 & no m5tion 0 made ( ! way 9 :i* ! gr\nd wire 0 gr\nd$1 or ( ! numb] ( its gr\nd connections4 ,fur!rmore1 x does n appe> t !re 0 m ?an "o gu>d wire on ea* pole l9e4 ,"u ^! circum/ances1 & ) a c]ta9 make ( lightn+ arre/]s 9 use at ! /ation1 lightn+ 0 a frequ5t cause ( damage to ! connect$ app>atus4 ,! insulation ( "s ( ! ma*9]y is describ$ z honeycomb$ ) p]=ations :i* l$ to cont9ual leakage1 gr\nds1 & %ort-circuits1 :i* seems to indicate t ! damage 0 be+ done by /atic & inductive dis*>ges r ?an by direct lightn+ /rokes1 "o ( :i* w\ld h disabl$ a ma*9e at once4 ,! type ( lightn+ arre/] 9 use on ?is sy/em 0 *ang$1 & ?or\gh gr\nd connections 7 provid$ = ! new arre/]s1 aft] :i* ! damage by lightn+ came to an end4 ,x is n /at$1 h[ev]1 t ! gu>d wires 7 remov$4 ,?is case has be5 ref]r$ to z "o 9 :i* gu>d wires fail$ to give protection1 b1 z may be se5 f ! above facts1 su* a /atem5t is h>dly fair4 ,9 ! fir/ place1 x does n appe> t ! s+le gu>d wire on ea* pole l9e 0 effectively gr\nd$ any:]e4 ,aga91 a l>ge "p ( ! damage to app>atus appe>s to h be5 ! result ( /atic or inductive dis*>ges t c\ld n 9 ! nature ( ?+s h be5 prev5t$ by a gu>d wire4 ,f9ally1 z ! gu>d wire 0 n remov$ aft] ! new lightn+ arre/]s 7 erect$1 x is possible t ?is wire prev5t$ "s direct dis*>ges ov] ! transmission wires t w\ld h be5 de/ructive4 ,on page #cha ( ! volume ( ,a4 ,i4 ,e4 ,e4 above cit$1 x is /at$ t ! frequ5cy & viol5ce ( lightn+ dis*>ges t ent]$ a c]ta9 electric /ation on ,/at5 ,isl& 7 mu* less aft] gu>d wires _h be5 erect$ along ! connect$ circuits ?an !y 7 be=e ! gu>d wires 7 put up4 ,x is also /at$ on page #che ( ! same volume t exam9ation ( /ati/ics ( a numb] ( /ations 9 ?is c\ntry & ,europe _h %[n t 9 e case :]e an ov]head gu>d wire _h be5 erect$ ov] p[] circuits1 or :]e ^! circuits ran = _! entire di/ance b5ea? telegraph wires1 lightn+ _h giv5 no tr\ble on ! circuits s protect$4 ,un=tunately1 ! speak] :o made ?is /atem5t did n tell u :]e ! int]e/+ /ati/ics m5tion$ c\ld be consult$4 ,on ! fir/ pole l9e erect$ = p[] transmission f ,niag>a ,falls to ,buffalo1 two gu>d wires 7 /rung at opposite ends ( ! top cross-arm on gu>d irons !re locat$4 ,?is cross-arm also c>ri$ p>ts ( two p[] circuits1 & ! ne>e/ wires ( ^! circuits 7 di/ant ab\t ?irte5 in*es f ! gu>d irons4 ,^! gu>d wires 7 b>b$1 & gr\nd$ at e fif? pole1 accord+ to an acc\nt giv5 9 ,a4 ,i4 ,e4 ,e41 vol4 xviii41 at #ead & foll[+ pages4 ,! "* ( ! gr\nd connections is n /at$4 ,mu* tr\ble 9 ! way ( gr\nds & %ort circuits on ! transmission l9es 0 caus$ by ^! gu>d wires at times :5 !y 7 brok5 by ! weight ( ice coat+s & w9d pressure4 ,z a result ( ^! tr\bles ! gu>d wires 7 remov$ 9 #ahih4 ,s9ce t date x appe>s t ! transmission l9es betwe5 ,niag>a ,falls & ,buffalo h be5 )\t gu>d wires4 ,up to #aija1 accord+ to page #ecg 9 ! volume j cit$1 tw5ty p] c5t ( ! int]ruptions 9 op]ation at ! ,niag>a plant 7 caus$ by lightn+1 & x seems probable t ?is record applies to ! p]iod aft] #ahih1 :5 ! gu>d wires 7 remov$4 ,x is also /at$ t dur+ a s+le /orm ! l9e 0 /ruck five times1 & t five poles ) _! cross-arms 7 de/roy$4 ,if ^! direct lightn+ /rokes occurr$ :ile !re 7 no gu>d wires along ! l9e1 z seems to h be5 ! fact1 x is a fair "q :e!r su* wires well gr\nd$ w\ld n h c>ri$ (f ! dis*>ges )\t damage4 ,9 ,cali=nia1 ! c\ntry ( long transmissions1 ! use ( gu>d wires along ! pole l9es is q g5]al4 ,_m ( ^! l9es run ea/ & we/ across ! ,/ate1 & a s+le l9e may ?us h elevations 9 its diff]5t p>ts all ! way f t ( tide-wat] up to sev]al ?\s& feet above sea-level4 ,unless gu>d wires are /rung ) ^! l9es !re is mu* manife/ation ( induc$ or /atic electricity1 accord+ to an acc\nt at page #ech1 9 vol4 xviii41 ,a4 ,i4 ,e4 ,e41 :]e x is said t 9 ! abs5ce ( gu>d wires a p]son w be knock$ (f 8 feet e "t he t\*es a transmission wire t is entirely disconnect$ f ! s\rce ( p[]4 ,x is also said t ?is /atic *>ge on idle p[] l9es is suffici5t1 9 "t1 to puncture ! insulation ( ! connect$ app>atus4 ,on ! o!r h&1 :]e ! gr\nd$ & b>b$ gu>d wires are /rung ov] ! entire l5g?s ( ^! long p[] l9es1 ^! l9es may be h&l$ ) impunity :5 !y are idle4 ,gr\nd connections to ! gu>d wire are said to be made at ab\t e f\r? pole1 & to consi/ ( a wire /apl$ d[n ! face ( ! pole & jo9$ to an iron plate b5ea? its butt4 ,! b>b$ gu>d wire itself1 ( :i* ea* pole l9e appe>s to h b "o1 is regul>ly /apl$ to ! tops ( ! poles4 ,at ! ref]5ce j nam$ x is relat$ t on a c]ta9 transmission l9e runn+ ea/ & we/ across ! ,/ate = a di/ance ( =ty-six miles1 & protect$ by a gu>d wire1 no tr\ble 0 exp]i5c$ dur+ a sev]e /orm t swept nor? & s\? ov] ! l9e4 ,meantime ! damage on o!r l9es 9 ! same neighborhood1 & presumably n protect$ by gu>d wires1 0 l>ge4 ,illu/ration3 ,,fig4 #gb4--,transposition ( ,wires on ,*ambly ,montreal ,l9e4 ,betwe5 ! electric plant at ,*ambly1 on ! ,ri*elieu ,riv]1 & ,montreal1 ,quebec1 a di/ance ( #af4f miles1 a transmission l9e ( ?ree circuits on two pole l9es1 ) gu>d wires1 0 op]at$ f "s "t 9 #ahih to ,decemb] #a/1 #aijb1 or some:at m ?an f\r ye>s4 ,on ! date la/ nam$ ! dam t ma9ta9$ ! head ( wat] at ! ,*ambly /ation gave way1 & ! plant 0 %ut d[n dur+ ne>ly a ye> = repairs4 ,= z mu* z ?ree ye>s ?is l9e 0 op]at$ at #ab1jjj volts1 sixty-six cycles p] second1 two-phase4 ,dur+ ! rema9d] ( ! p]iod up to ! failure ( ! dam ! l9e 0 op]at$ at #be1jjj volts1 sixty-?ree cycles1 ?ree-phase4 ,9 ea* transmission two pole l9es 7 employ$ ) two cross-arms p] pole4 ,"o two-phase1 f\r-wire circuit 0 c>ri$ on ea* ( ?ree ( ^! cross-arms4 ,at ea* end ( ! upp] cross-arm on ea* pole1 & at a di/ance ( fifte5 in*es f ! ne>e/ p[] wire1 a gu>d wire 0 m\nt$ on a glass insulator4 ,a ?ird gu>d wire 0 m\nt$ on a glass insulator at ! top ( ea* pole1 & ?is ?ird gu>d wire 0 ab\t tw5ty in*es f ! ne>e/ p[] wire4 ,ea* ( ^! gu>d wires 0 made up ( two ,no4 #ab ,b4 ,w4 ,g4 galvaniz$ iron wires twi/$ toge!r1 ) a f\r-po9t b>b e five in*es ( l5g?4 ,poles c>ry+ ^! l9es 7 n9ety feet ap>t1 & at ea* pole all ?ree ( ! gu>d wires 7 connect$ by sold]$ jo9ts to a gr\nd wire t 0 /apl$ d[n ! side ( ! pole1 pass$ ?r\gh an iron pipe eight feet long1 & 0 !n twi/$ sev]al times ab\t ! butt ( ! pole be=e x 0 set 9 ! gr\nd4 ,at ?ree po9ts along ! l9e ! conductors consi/$ ( s+le-conductor und]gr\nd or subm>9e cables t _h an aggregate l5g? ( ab\t tw5ty-five miles4 ,no lightn+ arre/]s 7 employ$ at ! po9ts :]e ! ov]head transmission wires jo9$ ! und]gr\nd cables4 ,^! two-phase1 #ab1jjj-volt circuits 7 op]at$ f "s "t 9 #ahih to "s "t 9 #aijb1 & dur+ t "t !re 0 no damage done by lightn+ ei!r at ! ,*ambly plant1 on ! ov]head l9e or ! und]gr\nd cable1 or at ! ,montreal sub-/ation4 ,?is record is n due to lack ( ?und]-/orms1 = 9 ! t]ritory :]e ! l9e is locat$ ^! /orms are frequ5t & sev]e4 ,"o v sev]e /orm dur+ ! p]iod 9 "q result$ 9 s]i\s damage on di/ribution l9es at ,*ambly & ,montreal1 :]e ! gu>d wires 7 n 9 use1 b ! transmission l9e & its connect$ app>atus escap$ unh>m$4 ,! pa? ( ?is /orm 0 9 ! direction ( ! transmission l9e f ,montreal to ,*ambly1 & sev]al trees 7 /ruck on ! way4 ,at ! "t ( ?is /orm & dur+ an entire summ] !re 7 no lightn+ arre/]s 9 ! p[]-h\se at ,*ambly4 ,9 #aijb1 :5 ! transmission l9e j consid]$ 0 *ang$ f two-phase to ?ree-phase1 & its voltage rais$ f #ab1jjj to #be1jjj1 ! me?od ( protection by gr\nd$1 b>b$ gu>d wires1 z above describ$1 0 reta9$4 ,two ?ree-phase circuits 7 arrang$ on ea* ( ! two pole l9es1 ) "o wire ( ea* circuit on an upp] cross-arm & two wires ( ea* circuit on a l[] cross-arm1 s t ! ne>e/ p[] wire on ! upp] cross-arm is ?irty-two in*es f ! gu>d wire1 & ! ne>e/ p[] wire on ! l[] cross-arm is ab\t ?irty in*es f ! gu>d wire at ea* end ( ! upp] cross-arm4 ,! gu>d wire at ! tops ( ! poles is ab\t ?irty-?ree in*es f ea* ( ! p[] wires on ! upp] cross-arm4 ,9 ?is ?ree-phase l9e !re is ab\t #a1ddj feet ( ?ree-conductor und]gr\nd cable1 & ?is cable lies betwe5 ! end ( ! ov]head l9e & ! sub-/ation 9 ,montreal4 ,at ! juncture ( ! ov]head l9e & ! cables !re is a t]m9al h\se conta9+ lightn+ arre/]s1 & !re are also arre/]s at ! ,*ambly plant & ! ,montreal sub-/ation4 ,no lightn+ arre/]s are connect$ to ?is l9e save ^? at ! g5]at+ plant1 ! t]m9al h\se & ! sub-/ation4 ,dur+ t "p ( ! ye> #aijb 9 :i* ! new #be1jjj-volt l9e 0 9 op]ation--t is1 aft] ! *ange & up to ! "t ( ! failure ( ! dam--?is l9e & its connect$ app>atus 7 n damag$ 9 any way by lightn+1 & ! same is true = ! p]iod 9 :i* ! l9e 0 idle p5d+ repairs on ! dam4 ,! exp]i5ce on ?is ,montreal & ,*ambly transmission is probably among ! be/ evid5ce to be f\nd any:]e z to ! degree ( protection f lightn+ t may be _h by ! use ( gu>d wires4 ,9 spite ( cases l t j consid]$1 :]e gu>d wires appe> to h giv5 a l>ge degree ( protection to transmission sy/ems1 _m important transmissions are op]at$ )\t !m4 ,an example ( ?is sort may be se5 9 ! transmission l9e betwe5 ! #aj1jjj-;horse-p[] plant at ,electra1 9 ! ,si]ra ,nevada ,m\nta9s ( ,cali=nia1 & ,san ,francisco1 a di/ance ( #aed miles1 :]e x seems t no gu>d wires are 9 use4 ,ano!r important transmission l9e t appe>s to get along )\t gu>d wires is t betwe5 ! #aj1jjj-;horse-p[] plant at ,caon ,f]ry1 on ! ,miss\ri ,riv]1 & ,butte1 ,mont41 sixty-five miles away4 ,on ! transmission l9e betwe5 ! p[]-/ation on ,apple ,riv]1 9 ,wiscons91 & ! sub-/ation at ,/4 ,paul1 ,m9n41 ab\t tw5ty-sev5 miles long1 !re are no gu>d wires = lightn+ protection4 ,fur!r ea/1 on ! l>ge1 new transmission sy/em t /ret*es f ,spi] ,falls & ,gl5s ,falls on ! nor? to ,albany on ! s\?1 a di/ance 9 a direct l9e ( =ty miles1 no gu>d wires are employ$4 ,on its way ! transmission sy/em j nam$ t\*es ,s>atoga1 ,s*5ectady1 ,me*anicsville1 ,troy1 & a numb] ( small] places1 ?us =m+ a network ) sev]al hundr$ miles ( ov]head wire4 ,examples ( ?is sort might be multipli$1 b ^? already nam$ are suffici5t to %[ t x is entirely practicable to op]ate long transmission sy/ems )\t gu>d wires z a protection aga9/ lightn+4 ,) ^! examples ( transmission sy/ems bo? ) & )\t gu>d wires1 ! exp$i5cy ( _! use on any p>ticul> l9e %\ld be det]m9$ by weigh+ _! suppos$ advantages aga9/ _! kn[n disadvantages1 "u ! exi/+ conditions4 ,x seems fairly c]ta9 f all ! evid5ce at h& t if gu>d wires are to (f] any l>ge degree ( protection to transmission sy/ems su* wires mu/ be frequ5tly & effectively gr\nd$4 ,!re is c]ta9ly "s reason to ?9k t ! failures ( gu>d wires to protect transmission sy/ems 9 "s in/ances may h be5 due to ! lack ( num]\s & effective gr\nd connections4 ,su*1 = example1 may h be5 ! case above m5tion$1 at ,telluride1 ,col4 ,on ! o!r h&1 x seems reasonable to believe t ! app>5tly high degree ( protection af=d$ by ! gu>d wires on ! ,*ambly & ,montreal l9e is due to ! fact t ^! wires are connect$ ?r\gh sold]$ jo9ts at e pole ) a gr\nd wire t is w\nd ab\t its base4 ,! ne>] ! gu>d wires are locat$ to ! p[] wires on a l9e ! great] is ! dang] t a gu>d wire w come into contact ) a p[] wire by break+ or o!rwise4 ,x is probable t ! protection giv5 by a gu>d wire does n increase ne>ly z fa/ z ! di/ance betwe5 x & a p[] wire is dim9i%$4 ,ev5 if "o gu>d wire on a l9e is ?\ght to be desirable1 x does n foll[ t two or m su* wires %\ld be us$1 = ! additional protection giv5 by two or ?ree gu>d wires beyond t giv5 by "o wire may be trifl+1 :ile ! co/ ( erection & ! dang] ( crosses ) ! p[] circuits increase directly ) ! numb] ( gu>d wires4 ,at "o "t x 0 ?\ght v desirable to h b>bs on gu>d wires1 b n[ ! bett] op9ion seems to be t1 z b>bs t5d to weak5 ! wire1 !y lead to breaks & cause m tr\ble ?an !y are wor?4 ,! po9t :]e ! b>bs are locat$ seems to ru/ m quickly ?an d o!r p>ts ( ! wire4 ,9 "s cases b>b$ gu>d wires t h giv5 tr\ble by break+ h be5 tak5 d[n & smoo? wires put up in/ead4 ,if a gu>d wire is well gr\nd$ at lea/ z (t5 z e o!r pole1 its size may be det]m9$ l>gely on consid]ations ( me*anical /r5g? & la/+ qualities4 ,= ord9>y spans a ,no4 #d ,b4 ,s4 ,g4 galvaniz$ s(t iron wire seems to be ab\t "r = gu>d+ purposes4 ,iron seems to be ! mo/ desirable mat]ial = gu>d wires because x gives ! requir$ me*anical /r5g? & suffici5t conductivity at a less co/ ?an copp]1 alum9um1 or bronze1 & is easi] to h&le & less liable to break ?an /eel4 ,x 0 =m]ly ! practice to /aple gu>d wires to ! tops ( poles or to ! ends ( cross-arms1 b x 0 f\nd t ! wire 0 m apt to ru/ & break at ! /aple ?an else:]e1 & 9 ! bett] class ( "w su* wires are n[ m\nt$ on small insulators4 ,?is practice1 z /at$ above1 0 foll[$ on ! ,montreal & ,*ambly l9e4 ,9 all cases ! connection betwe5 ! gu>d wire & ea* ( its gr\nd wires %\ld be sold]$1 & ! gr\nd wire %\ld h a l>ge surface 9 contact ) damp e>?1 ei!r ?r\gh a sold]$ jo9t ) a gr\nd plate1 by w9d+ a numb] ( turns ab\t ! butt ( ! pole1 or by o!r means4 ,x is ?\ght by "s telegraph eng9e]s t ! use ( a sep>ate gr\nd wire runn+ to ! top ( ea* pole is q z effective z a protection aga9/ lightn+ z is a gu>d wire t runs to all ( ! poles & is frequ5tly connect$ to ! gr\nd4 ,?is practice is m5tion$ at page #bf ( 8,culley's ,h&book ( ,practical ,telegraphy40 ,su* gr\nd wires are free f mo/ ( ! objections to ! ord9>y gu>d wires4 ,x seems q c]ta9 t a gu>d wire along an alt]nat+-curr5t l9e1 & gr\nd$ at frequ5t int]vals1 mu/ act z a second>y circuit ( a trans=m] by reason ( its gr\nd connections1 & ?us absorb "s en]gy f ! p[] circuits4 ,no exp]im5tal data are yet available1 h[ev]1 to %[ h[ l>ge ?is loss may be 9 an ord9>y case4 ,x is fairly evid5t t !re mu/ be "s electro/atic effects betwe5 ! work+ conductors & a gu>d wire1 b "h aga9 data are lack+ z to ! am\nt ( any su* effect4 ,on mo/1 if n all1 transmission l9es ! gu>d wire or wires1 if us$ at all1 are plac$ ei!r above or on a level ) ! highe/ p[] conductors4 ,) "o conductor ( a ?ree-phase circuit m\nt$ on a p9 set 9 ! top ( a pole1 & ! two rema9+ conductors on a two-p9 cross-arm b5ea?1 9 ! me?od mo/ frequ5tly adopt$ = transmission l9es ( v high voltage1 x is obvi\sly impracticable to put gu>d wires ei!r above or on a level ) ! p[] circuits4 ,9 ! late/ transmissions !re is a /rong t5d5cy to omit gu>d wires entirely & rely on lightn+ arre/]s = protection4 ,lightn+ arre/]s are wrongfully nam$1 = _! true purpose is n to arre/ or /op lightn+1 b to (f] x s easy a pa? to ! gr\nd t x w n =ce its way ?r\gh ! insulation ( ! l9e or ( ma*9]y connect$ to ! sy/em4 ,! requirem5ts ( a lightn+ arre/] are 9 a degree conflict+1 because ! resi/ance ( ! pa? x (f]s mu/ be s l[ z to all[ dis*>ges ( atmosph]ic electricity to e>? & s high z to prev5t any fl[ ( curr5t betwe5 ! transmission l9es4 ,9 o!r words1 ! insulation ( ! l9e conductors mu/ be ma9ta9$ at a high /&>d 9 spite ( ! connection ( lightn+ arre/]s betwe5 ea* conductor & ! e>?2 b ! resi/ance to ! arre/] mu/ n be s high t lightn+ w pi]ce ! insulation ( ! l9e or ma*9]y at "s o!r po9t4 ,:5 a lightn+ dis*>ge takes place ?r\gh an arre/] ! resi/ance :i* ! arre/] (f]s to a fl[ ( curr5t is = ! mom5t greatly r$uc$ by ! arcs :i* ! lightn+ sets up 9 jump+ ! air-gaps ( ! arre/]4 ,ea* wire ( a transmission circuit mu/ be connect$ alike to arre/]s1 & ! pa?s ( l[ resi/ance ?r\gh arcs 9 ^! arre/]s to ! e>? w\ld obvi\sly %ort-circuit ! connect$ g5]ators unless "s con/ruction 7 adopt$ to prev5t ?is result4 ,9 "s e>ly types ( lightn+ arre/]s magnetic or me*anical devices 7 resort$ to 9 ord] to break arcs =m$ by ! dis*>ge ( lightn+4 ,! type ( lightn+ arre/] n[ 9 common use on transmission l9es ) alt]nat+ curr5t includes a r[ ( %ort1 p>allel1 brass cyl9d]s m\nt$ on a porcela9 block & ) air-gaps ( "o-?irty-second to "o-sixte5? ( an in* betwe5 _! p>allel sides4 ,! cyl9d] at "o end ( ! r[ is connect$ to a l9e wire & ! cyl9d] at ! o!r end to ! e>?1 :5 a #b1jjj or #b1ejj-volt circuit is to be protect$4 ,= high] voltages a numb] ( ^! s+le arre/]s are connect$ 9 s]ies ) ea* o!r & ) ! free ends ( ! s]ies to a l9e wire & to ! e>?1 respectively4 ,?us1 = a #aj1jjj-volt l9e1 f\r or1 bett]1 five s+le arre/]s are connect$ 9 s]ies to =m a composite arre/] = ea* l9e conductor4 ,= any giv5 l9e voltage ! numb] ( s+le arre/]s go+ to make up ! composite arre/] %\ld be s *os5 t ! regul> work+ voltage w n jump ! s]ies ( air-gaps betwe5 ! little brass cyl9d]s1 b yet s t any l>ge rise ( voltage w be suffici5t to =ce sp>ks across ^! gaps4 ,a v>iation ( ?is practice by "o l>ge manufactur+ company is to m\nt ! gr\p ( s+le arre/]s on a m>ble bo>d 9 s]ies ) ea* o!r & ) an adju/able air-gap4 ,?is gap is int5d$ to be s adju/$ t any l>ge increase ( voltage on ! l9es w be reliev$ by a sp>k dis*>ge4 ,an arre/] made up entirely ( ! brass cyl9d]s & air-gaps has ! disadvantage t an arc once />t$ betwe5 all ! cyl9d]s by a lightn+ dis*>ge s l[]s ! resi/ance betwe5 ea* l9e wire & ! e>? t ! g5]at+ equipm5t is %ort-circuit$ & ! arcs may n cease ) ! escape ( atmosph]ic electricity4 ,to avoid ?is difficulty x is ! practice to connect a conductor ( r l>ge ohmic resi/ance su* z a rod ( c>borundum 9 s]ies ) ! brass cyl9d]s & air-gaps ( lightn+ arre/]s4 ,?is resi/ance %\ld be non-inductive s z n to (f] a s]i\s ob/acle to lightn+ dis*>ge1 & its resi/ance %\ld be great en\gh to prev5t a fl[ ( curr5t f ! g5]ators t w be l>ge en\gh to ma9ta9 ! arcs />t$ 9 ! arre/] by ! lightn+ dis*>ge4 ,accurate data are lack+ z to ! am\nt ( ?is resi/ance t %\ld be employ$ ) arre/]s = any giv5 voltage4 ,z a r\gh1 approximate rule x may be said t 9 "s cases good results w be obta9$ ) a resi/ance 9 ohms 9 s]ies ) a gr\p ( lightn+ arre/]s t repres5ts "o p] c5t ( ! num]ical value ( ! l9e voltage4 ,t is1 = a #aj1jjj-volt l9e ! gr\p ( arre/]s = ea* wire may be connect$ to e>? ?r\gh a resi/ance (1 say1 #ajj ohms1 s t if ! g5]ator curr5t foll[s ! arc ( a lightn+ dis*>ge ?r\gh ! arre/]s x mu/ pass ?r\gh a fix$ resi/ance ( #bjj ohms 9 go+ f "o l9e wire to ano!r4 ,?is rule is giv5 m]ely z an illu/ration ( ! resi/ance t w "w well 9 "s cases1 & %\ld n be tak5 to h a g5]al application4 ,if ! resi/ance connect$ 9 s]ies ) lightn+ arre/]s is high1 ! t5d5cy is a little great] = lightn+ to g to e>? at "s po9t 9 ! app>atus :]e ! insulation is l[4 ,if only a small resi/ance is employ$ to connect lightn+ arre/]s ) ! e>?1 ! dang] is t arcs =m$ by lightn+ dis*>ges w be foll[$ & ma9ta9$ by ! dynamo curr5ts4 ,9 "o make ( lightn+ arre/] ! r[ ( little brass cyl9d]s is connect$ at ! ends to c>bon rods :i* =m a resi/ance = ! purpose j m5tion$4 ,two ( ^! c>bon rods are conta9$ 9 ea* arre/] = #b1jjj or #b1ejj volts1 & ! resi/ance ( ea* rod may be any:]e f sev]al score to sev]al hundr$ ohms z desir$4 ,?is =m ( arre/] may be connect$ directly f l9e to e>? )\t ! int]v5tion ( any outside resi/ance1 s9ce ! c>bon rods may easily be giv5 all ! resi/ance t is desirable4 ,"o ( ! mo/ important features 9 ! erection ( a lightn+ arre/] is its connection to e>?4 ,if ?is connection is poor x may r5d] ! arre/] useless s f> z protection f lightn+ is conc]n$4 ,x ne$ h>dly be said t gr\nd connections =m$ by driv+ long iron spikes into ! walls ( build+s or into dry e>? are ( slight value z f> z protection f lightn+ is conc]n$4 ,a good gr\nd connection = lightn+ arre/]s may be =m$ ) a copp] or galvaniz$ iron plate1 :i* ne$ n be ov] "o-sixte5? ( an in* ?ick1 b %\ld h an area (1 say1 t5 to tw5ty squ>e feet4 ,?is plate may be conv5i5tly made up into ! =m ( a cyl9d] & %\ld h a numb] ( half-in* holes pun*$ 9 a r[ d[n "o side into :i* "o or m copp] wires ) an aggregate area equal to t ( a ,no4 #d or ,no4 #b wire1 ,b4 ,s4 gauge1 %\ld be ?read$ & !n sold]$4 ,?is plate or cyl9d] %\ld be plac$ deep en\gh 9 ! gr\nd to insure t ! e>? ab\t x w be con/antly moi/1 & ! connect$ copp] wire %\ld ext5d to ! lightn+ arre/]s4 ,x is a good plan to surr\nd ?is cyl9d] ) a lay] ( coke or *>coal4 ,a good e>? connection = lightn+ arre/]s may be made ?r\gh l>ge wat]-pipes1 b to d ?is x is n en\gh simply to wrap ! wire f ! lightn+ arre/]s ab\t ! pipe4 ,a suitable contact ) su* a pipe may be made by tapp+ "o or two l>ge bolts into x & !n sold]+ ! wires f lightn+ arre/]s into holes drill$ 9 ! heads ( ^! bolts4 ,a metal plate laid 9 ! b$ ( a /ream makes a good gr\nd4 ,) "s ( ! old] types ( lightn+ arre/]s x 0 ! cu/om to ins]t a fuse betwe5 ! l9e wire & ! gr\nd1 b ?is practice defeats ! purpose = :i* ! arre/] is erect$ because ! fuse melts & leaves ! arre/] disconnect$ & ! circuit unprotect$ ) ! fir/ lightn+ dis*>ge4 ,! mod]n arre/]s = alt]nat+-curr5t circuits are made up ( a s]ies ( metal cyl9d]s & %ort air-gaps & are connect$ solidly )\t fuse betwe5 l9e & e>?4 ,illu/ration3 ,,fig4 #gc4--;,entry ( ,l9es at ! ,p[]-h\se on ,nev]s9k ,riv]4 ,x 0 once ! practice to locate lightn+ arre/]s almo/ entirely 9 ! /ations1 b ?is has be5 modifi$ by exp]i5ce & consid]ation ( ! fact t z ! l9e acts z a collector ( atmosph]ic electricity1 pa?s = its escape %\ld be provid$ along ! l9e4 ,consid]ation fails to reveal any good reason :y lightn+ t rea*es a transmission l9e "s miles f a /ation %\ld be =c$ to travel to ! /ation1 :]e x may d great damage be=e x f9ds an easy pa? to e>?4 ,x is1 !re=e1 pres5t practice to connect lightn+ arre/]s to ea* wire at int]vals along "s l9es z well z at /ations & sub-/ations4 ,! ma9 purpose ( arre/]s is to (f] s easy a pa? to e>? t lightn+ dis*>ges along ! l9es w n fl[ to po9ts ( l[ insulation 9 g5]ators1 trans=m]s1 or ev5 ! l9e itself4 ,practice is f> f uni=m z to ! di/ance betwe5 lightn+ arre/]s on transmission l9es1 ! di/ances v>y+ f less ?an "o to a l>ge numb] ( miles ap>t4 ,9 g5]al ! l9es %\ld be provid$ ) lightn+ arre/]s at lea/ :]e !y run ov] hilltops & at any po9ts :]e lightn+ /rokes are unusually frequ5t4 ,:]e a long ov]head l9e jo9s an und]gr\nd cable arre/]s %\ld always be connect$1 & ! same is true z to trans=m]s locat$ on ! transmission l9e4 ,! multiplication ( arre/]s along pole l9es %\ld be avoid$ z f> z is consi/5t ) suitable protection1 because e bank ( arre/]s may develop a p]man5t gr\nd or %ort-circuit1 unless frequ5tly inspect$ & kept clean & 9 good condition4 ,arre/]s1 besides ^? connect$ along ! l9es1 %\ld be locat$ ei!r 9 or j outside ( /ations & sub-/ations4 ,if ! build+s are ( wood1 ! arre/]s _h bett] be outside 9 wea!r-pro( cases1 b 9 brick or /one build+s ! arre/]s may be prop]ly locat$ ne> an int]ior wall & well remov$ f all o!r /ation equipm5t4 ,transmission l9es1 on ent]+ a /ation or sub-/ation1 %\ld pass to ! arre/]s at once & be=e connect+ ) any ( ! op]at+ ma*9]y4 ,to increase ! degree ( protection af=d$ by lightn+ arre/]s *oke-coils are frequ5tly us$ ) !m4 ,a *oke-coil = ?is purpose usually consi/s ( a flat coil ( copp] wire or /rip conta9+ tw5ty to ?irty or m turns & m\nt$ ) t]m9als 9 a wood5 frame4 ,?is coil is connect$ 9 s]ies ) ! l9e wire betwe5 ! po9t :]e ! tap = ! lightn+ arre/] is made & ! /ation app>atus4 ,lightn+ dis*>ges are kn[n to be ( a highly oscillatory "*1 _! frequ5cy be+ mu* great] ?an t ( ! alt]nat+ curr5ts develop$ 9 transmission sy/ems4 ,! self-induction ( a lightn+ dis*>ge 9 pass+ ?r\gh "o ( ^! *oke-coils is great1 & ! consequ5t t5d5cy is to keep ! dis*>ge f pass+ ?r\gh ! *oke-coil & into ! /ation app>atus & ?us to =ce ! dis*>ge to pass to e>? ?r\gh ! lightn+ arre/]4 ,! alt]nat+ curr5t employ$ 9 transmission has su* a comp>atively l[ frequ5cy t its self-induction 9 a *oke-coil is small4 ,increas$ protection aga9/ lightn+ is giv5 by ! connection ( sev]al gr\ps ( lightn+ arre/]s "o aft] ano!r on ! same l9e wire at an electric /ation4 ,?is gives any lightn+ dis*>ge t may come along ! wire sev]al pa?s to e>? ?r\gh ! diff]5t gr\ps ( arre/]s1 & a dis*>ge t passes ! fir/ gr\p w probably g to e>? ov] ! second or ?ird gr\p4 ,9 "s cases a *oke-coil is connect$ into a l9e wire betwe5 ea* two gr\ps ( lightn+ arre/]s z well z betwe5 ! /ation app>atus & ! gr\p ( arre/]s ne>e/ !reto4 ,an electric transmission plant at ,telluride1 ,col41 :]e ?und]-/orms are v frequ5t & sev]e1 0 equipp$ ) arre/]s & *oke-coils ( ! type describ$1 & ! results 7 c>efully not$ 7vol4 xi41 ,a4 ,i4 ,e4 ,e41 p4 #cdf74 ,a small h\se = arre/]s & *oke-coils 0 built close to ! g5]at+ /ation ( ?is sy/em & !y 7 m\nt$ !re9 on wood5 frames4 ,f\r *oke-coils 7 connect$ 9 s]ies ) ea* l9e wire1 & betwe5 ^! *oke-coils ?ree lightn+ arre/]s 7 connect$1 :ile a f\r? arre/] 0 connect$ to ! l9e be=e x rea*$ any ( ! *oke-coils4 ,^! arre/]s 7 wat*$ dur+ an entire lightn+ season to see :i* bank ( arre/]s on ea* wire dis*>g$ ! mo/ lightn+ to e>?4 ,x 0 f\nd t1 beg9n+ on ! side t ! l9e came to ! s]ies ( arre/]s1 ! fir/ bank ( arre/]s 0 trav]s$ by only a few dis*>ges ( lightn+1 ! second bank by m dis*>ges ?an any o!r1 ! ?ird bank by q a l>ge numb] ( dis*>ges1 & ! f\r? bank seldom %[$ any sign ( lightn+ dis*>ge4 ,ov] ! second bank ( arre/]s ! lightn+ dis*>ges w\ld (t5 foll[ ea* o!r ) great rapidity & l\d noise4 ,! obvi\s conclusion f ^! obs]vations seems to be t ?ree or f\r banks ( lightn+ arre/]s connect$ 9 succession on a l9e at a /ation toge!r ) *oke-coils =m a mu* bett] protection f lightn+ ?an a s+le bank4 ,at ! plant 9 "q1 t ( ! ,san ,miguel ,consolidat$ ,gold ,m9+ ,company1 ! entire lightn+ season aft] ! erection ( ! arre/]s 9 "q 0 pass$ )\t damage by lightn+ to any ( ! equipm5t4 ,dur+ ! two lightn+ seasons previ\s to t j nam$ ! damage by lightn+ to ! g5]at+ ma*9]y at ! plant _h be5 frequ5t & ext5sive4 ,a good illu/ration ( ! high degree ( security aga9/ lightn+ dis*>ges t may be atta9$ ) lightn+ arre/]s & *oke-coils exi/s at ! ,niag>a ,falls plants & ! t]m9al h\se 9 ,buffalo1 :]e ! /ep-up & /ep-d[n trans=m]s h nev] be5 damag$ by lightn+ ?\gh ! transmission l9e has be5 /ruck repeat$ly & poles & cross-arms %att]$ 7vol4 xviii41 ,a4 ,i4 ,e4 ,e41 p4 #ebg74 ,?is example be>s out ! g5]al exp]i5ce t lightn+ arre/]s1 ?\gh n an absolute protection1 af=d a high degree ( security to ! app>atus at electric /ations4 ,lightn+ arre/]s are 9 "s cases connect$ across high-voltage circuits f wire to wire s t ! full l9e pressure t5ds to =ce a curr5t across ! air-gaps4 ,! object ( ?is practice is to gu>d aga9/ excessive voltages on ! circuit su* z might be due to resonance4 ,9 su* a case1 z 9 t :]e arre/]s are connect$ f l9e wire to e>? z a protection aga9/ lightn+1 ! numb] ( air-gaps %\ld be su* t ! normal l9e voltage w n =ce sp>ks across ! air-gaps & ?us />t arcs betwe5 ! cyl9d]s4 ,! numb] & total l5g? ( air-gaps 9 a bank ( arre/]s necess>y to prev5t ! =mation ( arcs by ! regul> l9e voltage dep5ds on a numb] ( factors besides ! am\nt ( t voltage4 ,accord+ to ! report ( ! ,committee on ,/&>dization ( ! ,am]ican ,in/itute ( ,electrical ,eng9e]s1 ! sp>k+ di/ances 9 air betwe5 oppos$ %>p ne$le po9ts = v>i\s effective s9usoidal voltages are z foll[s 7vol4 xix41 ,a4 ,i4 ,e4 ,e41 p4 #ajia73 ----------------------------------- ,kilovolt ,squ>e ,in*es ,sp>k+ ,root ( ,mean ,squ>e4 ,di/ance4 ----------------------------------- #e #j4bbe #aj 4#dg #ae 4#gbe #bj #a4j #be #a4c #cj #a4fbe #ce #b4j #dj #b4de #de #b4ie #ej #c4ee #fj #d4fe #gj #e4he #hj #g4a #ij #h4ce #ajj #i4f #aaj #aj4ge #abj #aa4he #acj #ab4ie #adj #ac4ie #aej #ae4j ----------------------------------- ,x may be not$ at once f ?is table t ! sp>k+ di/ance betwe5 ! ne$le po9ts increases mu* fa/] ?an ! voltage betwe5 !m4 ,?us1 #bj1jjj volts w jump an air-gap ( only an in* betwe5 ! po9ts1 b sev5 times ?is pressure1 or #adj1jjj volts1 w =ce a sp>k across an air-gap ( #ac4ie in*es4 ,two cyl9d]s or o!r blunt bodies %[ small] sp>k+ di/ances betwe5 !m at a giv5 voltage ?an d two ne$le po9ts1 b :5 a numb] ( cyl9d]s are plac$ 9 a r[ ) %ort air-gaps betwe5 !m ! aggregate l5g? ( ^! gaps t w j prev5t ! passage ( sp>ks at a giv5 voltage may be mat]ially great] or less ?an ! sp>k+ di/ance ( t voltage betwe5 ne$le po9ts4 ,x has be5 f\nd by exp]im5t t ! numb]s "o-?irty-second-in* sp>k-gaps betwe5 cyl9d]s ( non-arc+ alloy necess>y to prev5t ! passage ( sp>ks ) ! voltages nam$ & a s9e wave ( electromotive =ce are z foll[s 7vol4 xix41 ,a4 ,i4 ,e4 ,e41 p4 #ajbf73 ------------------- ,numb] ( ,normal #a_/cb-;,in* ,voltage ,air-,gaps ,)held4 9 ,s]ies4 ------------------- #e #f1hjj #aj #aj1jjj #ae #ab1ejj #bj #ad1ejj #be #af1djj #cj #ah1bjj #ce #ai1cjj #dj #bj1ejj #de #ba1gjj #ej #bb1fjj #ee #bc1ijj #fj #be1jjj #fe #bf1jjj #gj #bg1jjj #ge #bh1jjj #hj #bi1jjj ------------------- ,accord+ to ^! data1 only t5 air-gaps ( "o-?irty-second ( an in* ea* & #j4cabe in* comb9$ l5g? are requir$ betwe5 cyl9d]s to prev5t a dis*>ge at #aj1jjj volts1 ?\gh oppos$ ne$le po9ts may be #j4dg in* ap>t :5 a sp>k is obta9$ ) ?is voltage4 ,on ! o!r h&1 eighty air-gaps ( "o-?irty-second ( an in* ea* betwe5 cyl9d]s ( non-arc+ metal1 or a total gap ( #b4e in*es1 are necess>y to prev5t a dis*>ge at #bi1jjj volts1 ?\gh #cj1jjj volts c =ce a sp>k across a s+le gap ( only #a4fbe in*es betwe5 oppos$ ne$le po9ts4 ,"u ! conditions t exi/$ 9 ! te/ j record$ ! pressure at :i* ! aggregate l5g? ( "o-?irty-second ( an in* air-gaps t j prev5ts a dis*>ge equals ! s+le sp>k+ di/ance betwe5 ne$le po9ts seems to be ab\t #ah1jjj volts4 ,! object ( divid+ ! total air-gap 9 a lightn+ arre/] = l9es t c>ry alt]nat+ curr5t up into a numb] ( %ort gaps is to prev5t ! cont9uance ( an arc by ! regul> g5]ator or l9e curr5t aft] ! arc has be5 />t$ by a lightn+ dis*>ge4 ,z soon z an electric sp>k leaps ?r\gh air f metal to metal1 a pa? ( l[ electrical resi/ance is =m$ by ! int5sely heat$ air & metallic vapor4 ,if ! arc ?us =m$ is1 say1 two in*es long x w cool a c]ta9 am\nt z ! pass+ curr5t gr[s small & drops to z]o4 ,if1 h[ev]1 ?is total arc ( two in*es is divid$ into sixty-f\r p>ts by pieces ( metal1 ! process ( cool+ z ! curr5t decreases w g on mu* m rapidly ?an ) ! s+le arc ( two in*es because ( ! great conduct+ p[] ( ! pieces ( metal4 ,z an alt]nat+ curr5t comes to z]o twice 9 ea* p]iod1 ! _m %ort arcs =m$ 9 an arre/] by a lightn+ dis*>ge are s f> cool$ dur+ ! small values ( ! foll[+ l9e curr5t t ! resi/ance quickly rises to a po9t :]e ! regul> l9e voltage _c cont9ue to ma9ta9 !m1 if ! arre/] is prop]ly design$ = ! sy/em to :i* x is connect$4 ,9 ?is way ! _m-gap arre/] de/roys ! _m small arcs />t$ by lightn+ dis*>ges t w\ld cont9ue & %ort-circuit ! l9e if !y 7 comb9$ into a s+le long arc4 ,:5 an electric arc passes betwe5 c]ta9 metals l iron & copp] a small bead is rais$ on _! surfaces4 ,if ^! metals 7 us$ = ! cyl9d]s ( arre/]s ! beads on _! surface w\ld quickly bridge ! %ort air-gaps4 ,c]ta9 o!r metals1 l z9c1 bismu?1 & antimony1 are pitt$ by ! passage ( arcs betwe5 _! surfaces4 ,by suitable mixture ( metals f ^! two classes1 an alloy is obta9$ = ! cyl9d]s ( lightn+ arre/]s t pits only slightly & is ?us b little injur$ by lightn+ dis*>ges4 ,aft] long use & _m dis*>ges an arre/] ( ! class "h consid]$ gradually loses its p[] to de/roy electric arcs4 ,?is may be due to ! burn+ out ( ! z9c & leav+ a surface ( copp] on ! cyl9d]s4 ,aside f ! /ructure ( an arre/] & ! normal voltage ( ! circuit to :i* x is connect$1 its p[] to de/roy arcs set up by lightn+ dis*>ges dep5ds on ! capacity ( ! connect$ g5]ators to deliv] curr5t on a %ort-circuit ?r\gh ! gaps1 & ^u ! inductance ( ! circuit4 ,! great] ! capacity ( ! g5]ators connect$ to a sy/em ! m try+ are ! conditions "u :i* arre/]s mu/ break an arc because ! curr5t to be brok5 is great]4 ,s1 too1 an increase ( inductance 9 a circuit adds to ! "w ( an arre/] 9 break+ an arc4 ,an arc />t$ by lightn+ dis*>ge at t p]iod ( a voltage phase :5 x is at or ne> z]o is easily de/roy$ by ! arre/]1 b an arc />t$ at ! in/ant :5 ! regul> l9e voltage has its maximum value is mu* h>d] to break because ( ! great] am\nt ( heat g5]at$ by ! great] curr5t s5t ?r\gh ! arre/]4 ,= ?is reason ! arcs at arre/]s w hold on long] 9 "s cases ?an 9 o!rs1 accord+ to ! portion ( ! voltage phase 9 :i* !y are />t$ by ! lightn+ dis*>ge4 ,lightn+ dis*>ges1 ( c\rse1 may occur at any phase ( ! l9e voltage1 & = ?is reason a numb] ( dis*>ges mu/ take place be=e x c be c]ta9 f obs]vation t a p>ticul> arre/] w always break ! result+ arc4 ,betwe5 tw5ty-five & sixty cycles p] second !re is a small diff]5ce 9 favor ( ! latt] 9 ! p[] ( a giv5 arre/] to break an arc1 due probably to ! fact t m heat 9 ! arcs is develop$ p] phase ) ! l[] ?an ) ! high] frequ5cy4 ,x w n[ be se5 t :ile increase ( ! regul> l9e voltage requires a l5g!n+ ( ! aggregate air-gap 9 lightn+ arre/]s to prev5t ! =mation ( arcs by ?is voltage alone1 ! increase ( g5]at+ capacity requires m subdivisions ( ! total air-gap 9 ord] t ! arcs ma9ta9$ by ! l>g] curr5ts may be cool$ ) suffici5t rapidity4 ,^! two requirem5ts are to "s ext5t conflict+1 because ! subdivision ( ! total air-gaps r5d]s x less effective to prev5t dis*>ges due to ! normal l9e voltage1 z has already be5 %[n4 ,! result is t ! m an air-gap is subdivid$ 9 ord] to cool & de/roy arcs t h be5 />t$ by lightn+1 ! long] mu/ be ! aggregate air-gap 9 ord] to prev5t ! developm5t ( arcs directly by ! normal l9e voltage4 ,fur!rmore1 ! practical limit ( subdivision ( ! air-gap is soon rea*$ because ( ! difficulty ( keep+ v %ort gaps clean & ( ne>ly con/ant l5g?4 ,z a resi/ance 9 s]ies ) an arre/] cuts d[n ! g5]ator curr5t t c foll[ a lightn+ dis*>ge1 su* a resi/ance also decreases ! numb] ( air-gaps necess>y to give an arre/] p[] to de/roy arcs on a p>ticul> circuit4 ,! increase ( resi/ance 9 s]ies ) a lightn+ arre/] z well z ! increase 9 ! aggregate l5g? ( its air-gaps subjects ! insulation ( connect$ app>atus to great] /ra9s at times ( lightn+ dis*>ge4 ,on sy/ems ( l>ge capacity ! numb] & aggregate l5g? ( air-gaps 9 arre/]s necess>y to de/roy arcs mu/ be great] ?an ! numb] or l5g? ( ^! air-gaps necess>y to prev5t ! developm5t ( arcs by ! normal l9e voltage1 unless a relatively l>ge resi/ance is connect$ 9 s]ies ) ea* arre/]4 ,to r$uce ! /ra9s produc$ on ! insulation ( l9e & connect$ app>atus "u ^! conditions by lightn+ dis*>ges1 a resi/ance is connect$ 9 %unt ) a "p ( ! air-gaps 9 "o make ( lightn+ arre/]4 ,! net advantage claim$ = ?is type ( arre/] is t a l[] resi/ance may be us$ 9 s]ies ) all ! air-gaps ?an w\ld o!rwise be necess>y4 ,"o-half ( ! total numb] ( air-gaps 9 ?is arre/] are %unt$ by ! %unt resi/ance & ! s]ies & %unt resi/ance are 9 s]ies ) ea* o!r4 ,only ! s]ies air-gaps or ^? t are n %unt$ mu/ be jump$ 9 ! fir/ in/ance by ! lightn+ dis*>ge1 :i* ?us passes to e>? ?r\gh ^! air-gaps & ! %unt & s]ies resi/ance 9 s]ies4 ,an arc is next />t$ 9 ! %unt$ air-gaps1 & ?is arc is 9 turn de/roy$ because ! %unt weak5s ! curr5t 9 ^! gaps4 ,?is ?r[s ! entire curr5t ( ! arc ?r\gh ! s]ies air-gaps & ! %unt & s]ies resi/ance all 9 s]ies ) ea* o!r4 ,z ! %unt resi/ance is comp>atively l>ge1 ! curr5t ma9ta9+ ! arc 9 ! s]ies air-gaps is next s r$uc$ t ?is arc is brok54 ,tak+ ! claims ( its mak]s j z !y /&1 ! advantages ( ! %unt$ air-gaps are n v cle>4 ,! s]ies air-gaps alone mu/ evid5tly be su* t ! normal l9e voltage w n />t an arc ov] !m1 & ^! same s]ies gaps mu/ be able to break ! arcs ( l9e curr5t fl[+ ?r\gh !m & ! %unt & s]ies resi/ance all 9 s]ies4 ,evid5tly ! greate/ /ra9 on ! insulation ( ! l9e & app>atus occurs at ! in/ant :5 ! lightn+ dis*>ge takes place ?r\gh ! s]ies gaps & ! %unt & s]ies resi/ances all 9 s]ies ) ea* o!r4 ,:y develop subsequ5t arcs 9 ! %unt$ air-gaps8 ,:y n ?r[ ! %unt$ air-gaps away & comb9e ! %unt & s]ies resi/ances8 ,,*apt] ,,xiv4 ,,electrical ,,transmission ,,"u ,,l& ,,& ,,wat]4 ,en]gy transmitt$ ov] long di/ances mu/ sometimes pass ?r\gh conductors t are und]gr\nd or b5ea? wat]4 ,9 "s o!r cases x is a "q ( relative advantages m]ely1 :e!r portions ( a transmission l9e g "u wat] or ov]head4 ,:]e ! transmitt$ en]gy mu/ ent] a sub-/ation 9 ! he>t ( a l>ge city1 x n infrequ5tly mu/ g by way ( und]gr\nd conductors )\t reg>d to ! voltage employ$4 ,9 "s cities ! transmission l9es may be c>ri$ ov]head1 provid$ t _! voltage is )9 "s mod]ate figure1 b n o!rwise4 ,"h x becomes a "q :e!r transmission l9es at high voltage %all be c>ri$ und]gr\nd1 or :e!r trans=m+ /ations %all be e/abli%$ outside ( ! re/rict$ area & !n l[-pressure l9es br\ght into ! bus9ess section ov]head or und]gr\nd1 z desir$4 ,:]e a transmission l9e mu/ cross a /eam railway track x may be requir$ to be und]gr\nd1 :e!r ! voltage is r$uc$ or n4 ,! di/ance across a body ( wat] 9 ! pa? ( a transmission l9e may be s great t a span is impossible & a cable "u ! wat] !re=e necess>y4 ,su* a cable may "w at ! regul> l9e voltage1 or a trans=m] /ation may be e/abli%$ on "o side or on ea* side ( ! body ( wat]4 ,ev5 :]e x is possible to span a body ( wat] ) a transmission l9e1 ! co/ ( ! span & ( its supports may be s great t a subm>9e cable is m desirable4 ,a mod]ate increase 9 ! l5g? ( a transmission l9e 9 ord] to avoid ! use ( a subm>9e cable is almo/ always advisable1 b :]e riv]s are 9 ! pa? ( ! l9e x is g5]ally impossible to avoid cross+ !m ei!r ov]head or und]nea?4 ,?us1 ,/4 ,paul c\ld only be rea*$ ) ! #be1jjj-volt l9e f ! falls on ,apple ,riv] by cross+ ! ,/4 ,croix ,riv]1 "o-half mile wide1 on ! way4 ,9 ord] to c>ry out ! #dj1jjj-volt transmission betwe5 ,colgate & ,oakl&1 ! ,c>qu9ez ,/raits1 :i* int]v5$ ) ne>ly a mile ( cle> wat]1 7 cross$4 ,sometimes1 z 9 ! =m] ( ! two cases j nam$1 an exi/+ bridge may be utiliz$ to support a transmission l9e1 b m frequ5tly ! *oice lies betwe5 an ov]head span f bank to bank ( a riv] & a subm>9e cable betwe5 ! same po9ts4 ,! prime advantage ( an ov]head l9e at high voltage is its comp>atively small fir/ co/1 :i* is only a fraction ( t ( an und]gr\nd or subm>9e cable 9 ! great majority ( in/ances4 ,at v high voltages1 l #dj1jjj to #ej1jjj or m1 ! ov]head l9e mu/ also be giv5 fir/ place on ! score ( reliability1 s9ce ! la/+ qualities ( und]gr\nd & subm>9e cables at su* pressures is z yet an unkn[n quantity4 ,on ! o!r h&1 at voltages 9 :i* cable insulation has be5 %[n by exp]i5ce to be ?or\ghly effective1 und]gr\nd or subm>9e cables may be m reliable ?an ov]head l9es because ( ! great] fre$om f me*anical di/urbances :i* ^! cables enjoy4 ,9 ! bus9ess portion ( _m cities a transmission l9e mu/ g und]gr\nd1 :e!r its voltage is high or l[4 ,"u ^! conditions1 x may be desir$ ei!r to transmit en]gy to a sub-/ation = di/ribution )9 ! area :]e conductors mu/ be und]gr\nd1 or to transmit en]gy f a g5]at+ /ation !re locat$ to outside po9ts4 ,if ! transmitt$ en]gy is r$uc$ 9 pressure be=e rea*+ su* a sub-/ation1 a trans=m+ /ation mu/ be provid$1 & ?is w all[ ! und]gr\nd cables to op]ate at a mod]ate voltage4 ,= su* a case ! advantages z to insulation at ! l[] voltage %\ld be comp>$ ) ! additional weight ( conductors 9 ! cable & ! co/ ( ! trans=m+ app>atus & /ation4 ,if ! voltage at :i* curr5t is deliv]$ f ! trans=m+ /ation does n correspond ) ! requir$ voltage ( di/ribution at ! sub-/ation1 ! necess>y equipm5t ( /ep-d[n trans=m]s is d\bl$ 9 capacity by l[]+ ! voltage ( ! transmitt$ en]gy :]e x passes f ! ov]head l9e to ! und]gr\nd cables4 ,conditions ( j ?is sort exi/ at ,buffalo 9 connection ) ! deliv]y ( en]gy f ! p[]-/ations at ,niag>a ,falls4 ,?is transmission 0 fir/ c>ri$ out at #aa1jjj volts1 & a t]m9al /ation 0 locat$ at ! ,buffalo city limits :]e ! ov]head l9es jo9$ und]gr\nd cables t cont9u$ ! transmission at ! same voltage to sev]al sub-/ations 9 diff]5t p>ts ( ! city4 ,lat] ! voltage ( ! ov]head transmission l9e 0 rais$ to #bb1jjj1 & x n be+ ?\ght advisable to subject ! insulation ( ! und]gr\nd cables to ?is high] pressure1 trans=m]s 7 in/all$ at ! t]m9al /ation to l[] ! l9e voltage to #aa1jjj = ! und]gr\nd cables4 ,z ! sub-/ations 9 ?is case also h trans=m]s1 !re are two kil[atts ( capacity 9 /ep-d[n trans=m]s = ea* kil[att ( deliv]y capacity at ! sub-/ations4 ,illu/ration3 ,,fig4 #gd4--;,cable ,t]m9al ,h\se = ! #be1jjj-volt ,*ambly ,l9e at ,montreal4 ,! sav+ effect$ 9 capacity ( trans=m]s & 9 ! weight ( cables by cont9u+ ! full transmission voltage "r up to ! sub-/ations :5ce di/ribution takes place furni%es a /rong motive to "w und]gr\nd cables at ! pressure ( ! ov]head transmission l9e ( :i* !y =m a cont9uation4 ,?us1 at ,h>t=d1 ! #aj1jjj-volt ov]head l9es t br+ en]gy f wat]-p[] /ations to ! outskirts ( ! city connect directly 9 t]m9al h\ses !re ) und]gr\nd cables t complete ! transmission to ! sub-/ation at ! full l9e voltage4 ,9 ,spr+field1 ,mass41 ! ov]head transmission l9es f wat]-p[] /ations connect directly ) und]gr\nd cables at a di/ance ( ne>ly two miles f ! sub-/ation1 & ^! cables are ?us subject to ! full l9e pressure ( #f1jjj volts4 ,! ov]head l9e t br+s en]gy at #be1jjj volts f ,apple ,riv] falls to ,/4 ,paul t]m9ates ab\t ?ree miles f ! sub-/ation !re1 & ! transmission is complet$ by und]gr\nd cables t c>ry curr5t at ! #be1jjj-volt pressure4 ,9 ^! & simil> cases ! relative advantages ( und]gr\nd cables at ! full voltage ( transmission & ( ov]head l9es at a mu* l[] pressure1 9 ! c5tral portions ( cities1 mu/ be comp>$4 ,! ov]head l9es at mod]ate voltage w no d\bt co/ less 9 almo/ e case ?an und]gr\nd cables ( equal l5g? & at ! full transmission voltage4 ,z an (fset to ! l[] co/ ( ov]head city l9es at mod]ate voltage1 :]e !y are p]mitt$ by local regulations1 comes ! increase 9 weight ( conductors due to ! l[ pressure on ! ov]head l9es1 & also ! co/ ( additional trans=m] capacity1 unless ! l9es t complete ! transmission op]ate at ! voltage ( di/ribution4 ,! #aj1jjj-volt l9es t transmit en]gy f ,great ,falls to ,portl&1 ,me41 t]m9ate 9 two trans=m] h\ses t are di/ant ab\t #j4e mile & #b4e miles1 respectively1 f ! sub-/ation !re4 ,9 ^! trans=m] h\ses ! voltage is r$uc$ to #b1ejj1 & ! transmission is !n cont9u$ at ?is pressure to ! sub-/ation :5ce di/ribution takes place )\t fur!r trans=mation4 ,:]e a riv] or o!r body ( wat] mu/ be cross$ by a transmission l9e1 ei!r ( ?ree plans may be foll[$4 ,! ov]head l9e may be cont9u$ z su* across ! wat]1 ei!r by a s+le span or by two or m spans support$ by "o or m pi]s built = t purpose 9 ! wat]4 ,! ov]head l9e may connect directly ) a subm>9e cable1 ?is cable be+ ?us expos$ to ! full voltage ( ! transmission4 ,z a ?ird exp$i5t1 a subm>9e cable may be laid & connect$ ) /ep-d[n trans=m]s on "o bank & ) /ep-up trans=m]s on ! o!r bank ( ! riv] or o!r body ( wat] to be cross$4 ,! ov]head l9es connect+ ) ^! trans=m]s c obvi\sly be op]at$ at any desir$ voltage1 & ?is is also true ( ! cable4 ,ev5 ?\gh ! di/ance across a body ( wat] is n s great t a transmission l9e c n be c>ri$ ov] x 9 a s+le span1 ! co/ ( su* a span may be l>ge4 ,a case 9 po9t is t ( ! ,colgate & ,oakl& l9e1 :]e x crosses ! ,c>qu9ez ,/raits by a span ( #d1dbg feet4 ,^! /raits are ab\t #c1bjj feet wide :]e ! transmission l9e crosses1 & ov]head l9es 7 requir$ to be n less ?an #bjj feet above high wat] s z n to imp$e navigation4 ,9 ord] to ga9 9 gr\nd elevation & ?us r$uce ! necess>y height ( t[]s1 two po9ts #d1dbg feet ap>t on opposite sides ( ! /raits 7 select$ = _! location4 ,"u ^! circum/ances two /eel t[]s1 "o sixty-five feet & ! o!r #bbe feet high1 7 requir$ to support ! f\r /eel cables t act z conductors across ! /raits4 ,to take ! /ra9 ( ^! f\r cables1 ea* ) a cle> span ne>ly ?ree times z great z t ( ! ,brooklyn ,bridge1 eight an*ors ) h\s$ /ra9 insulators 7 con/ruct$1 f\r on ! l& side ( ea* t[]4 ,on ea* ( ^! an*ors ! /ra9 is said to be #bd1jjj p\nds4 ,at ea* end ( ! cables mak+ ?is span is a swit*-h\se :]e ei!r ( ! two ?ree-phase transmission l9es may be connect$ to any ?ree ( ! f\r /eel cables1 ?us leav+ "o cable free = repairs4 ,x is n possible to /ate "h ! relative co/ ( ^! /eel t[]s & cables 9 comp>ison ) t ( subm>9e cables = ! same "w1 b at fir/ glance ! "q appe>s to be an op5 "o4 ,! voltage ( #dj1jjj1 at :i* ?is transmission is c>ri$ out1 is probably high] ?an t on any subm>9e cable 9 use1 b x is possible t a suitable cable c be op]at$ at ?is voltage4 ,:atev] ! limitations ( voltage z appli$ to subm>9e cables1 x w\ld1 ( c\rse1 h be5 practicable to use /ep-up & /ep-d[n trans=m]s at ! swit*-h\ses & ?us op]ate a subm>9e cable at any voltage desir$4 ,9 ano!r case1 on a transmission betwe5 ,portsm\? & ,dov]1 ,n4 ,h41 x 0 necess>y to cross an arm ( ! sea on a l9e #d1haa feet long ) a ?ree-phase circuit op]at+ at #ac1ejj volts4 ,x 0 decid$ to avoid ! use ( ei!r a great span or ( rais+ & l[]+ trans=m]s at ?is cross+1 & to complete ! l9e ?r\gh a subm>9e cable op]at+ at ! full voltage ( transmission4 ,to ?is end a brick t]m9al h\se six by eight feet inside1 & ) an elevation ( ?irte5 feet f ! concrete floor to ! tile ro(1 0 erect$ on ea* bank ( ! bay at ! po9t :]e ! subm>9e cable came out ( ! wat]4 ,! lead-cov]$ cable pi]c$ ! f\ndation ( ea* ( ^! t]m9al h\ses at a po9t f\r feet bel[ ! floor level & rose !nce on "o wall to an elevation elev5 feet above ! floor to a po9t :]e connection 0 made ) ! ends ( ! ov]head l9es4 ,f ?is connection on ea* ( ! ?ree conductors a tap 0 c>ri$ to a swit* & s]ies ( lightn+ arre/]s4 ,a s+le lead-cov]$ cable conta9+ ?ree conductors makes connection betwe5 ^! two t]m9al h\ses4 ,at ea* end ( ?is cable ! lead %ea? jo9s a t]m9al bell "o foot long & #b4e in*es 9 outside diamet]1 increas+ to f\r in*es at ! end :]e ! ?ree conductors pass out4 ,?is t]m9al bell is fill$ ne>ly to ! fl>+ upp] end ) an insulat+ comp\nd4 ,9 ! in/ance j nam$ x is possible t ! co/ ( ! subm>9e cable 0 less ?an w\ld h be5 ! outlay = %ore supports & a span ne>ly a mile long across ?is body ( wat]4 ,und]gr\nd & subm>9e cables h be5 op]at$ at voltages suitable = transmission dur+ p]iods suffici5tly long to demon/rate _! g5]al reliability4 ,! ,f]ranti und]gr\nd cables betwe5 ,dept=d & ,london h regul>ly c>ri$ curr5t at #aa1jjj volts s9ce a date prior to #ahij4 ,dur+ ab\t five ye>s cables ) an aggregate l5g? ( sixte5 miles h transmitt$ p[] f ,/4 ,an?ony's ,falls to ,m9neapolis4 ,at ,buffalo1 "s ?irty miles ( rubb]-insulat$ cables h be5 9 use = und]gr\nd "w at #aa1jjj volts s9ce #ahig1 & eighte5 miles ( pap]-insulat$ cable s9ce ! fir/ "p ( #aija4 ,^! examples are en\gh to %[ t transmission ?r\gh und]gr\nd cables at #aa1jjj to #ab1jjj volts is entirely practicable4 ,at ,read+1 ,pa41 an und]gr\nd cable "o mile long has c>ri$ ?ree-phase curr5t at #af1jjj volts = ! ,oley ,valley ,railway s9ce "s "t 9 #aijb4 ,! cables 9 ! transmission f ,apple ,riv] to ,/4 ,paul1 :i* c>ry ?ree-phase curr5t at #be1jjj volts1 h a total l5g? ( ?ree miles1 & h be5 9 use s9ce #aijj4 ,?is voltage ( #be1jjj is probably ! highe/ 9 regul> use on any und]gr\nd or subm>9e cable convey+ en]gy = light or p[]4 ,f ! exp]i5ce ?us f> ga9$ !re is mu* reason to ?9k t ! voltages appli$ to und]gr\nd cables may be v mat]ially increas$ be=e a prohibitive co/ ( insulation is rea*$4 ,on subm>9e cables ! voltage ( #ac1jjj 9 ! ,portsm\? & ,dov] transmission1 above m5tion$1 is p]haps z great z any 9 use4 ,x does n appe>1 h[ev]1 t any mat]ial diff]5ce exi/s1 z to ! /ra9 on its insulation at a giv5 voltage1 betwe5 a cable :5 laid 9 an und]gr\nd conduit & :5 laid "u wat]4 ,9 ei!r case ! entire /ress ( ! voltage employ$ op]ates on ! insulation betwe5 ! sev]al conductors 9 ! cable & betwe5 ea* conductor & ! metallic %ea?4 ,und]gr\nd conduits h little or no value z insulators ( high voltages1 because x is practically impossible to keep !m wat]-tight & prev5t absorption or cond5sation ( moi/ure !re94 ,= ^! reasons a cable t gives good results at #be1jjj volts 9 an und]gr\nd conduit %\ld be available = use at an equal voltage "u wat]4 ,! /&>d /ructure ( high-voltage cables = ei!r und]gr\nd or subm>9e "w includes a cont9u\s metallic %ea? outside ( ea* conductor or ( ea* gr\p ( conductors t goes to make up a circuit4 ,z mo/ transmissions are n[ c>ri$ out ) ?ree-phase curr5t1 ! ?ree conductors correspond+ to a ?ree-phase circuit are usually conta9$ 9 a s+le cable & cov]$ by a s+le %ea?4 ,! cables us$ 9 transmission sy/ems at ,portsm\?1 ,buffalo1 & ,/4 ,paul are ( ?is type4 ,if s+le-phase or two-phase curr5t is transmitt$1 ea* cable %\ld conta9 ! two conductors t g to make up a circuit4 ,9 "w ) alt]nat+ curr5ts ! use ( only "o conductor p] cable %\ld be avoid$ because ( ! loss ( en]gy t results f ! curr5ts induc$ 9 ! metallic %ea? ( su* a cable4 ,illu/ration3 ,,fig4 #ge4--;,cable ,t]m9al ,h\se at ,piscataqua ,riv] ,cross+4 ,:]e ! two1 ?ree1 or m conductors t =m a complete circuit = alt]nat+ curr5t are includ$ 9 a s+le metallic %ea?1 ! inductive effects ( curr5ts 9 ! sev]al conductors t5d to neutralize ea* o!r & ! wa/e ( en]gy 9 ! %ea? is 9 l>ge "p avoid$4 ,to neutralize m completely ! t5d5cy to local curr5ts 9 _! metal %ea?1 ! sev]al insulat$ conductors ( an alt]nat+ circuit are sometimes twi/$ toge!r1 aft] be+ sep>ately insulat$1 be=e ! %ea? is put on4 ,di/ribution ( p[] at ,niag>a ,falls 0 at fir/ c>ri$ out ?r\gh s+le-conductor1 lead-cov]$ cables ) two-phase curr5t at #b1bjj volts4 ,"o objection to ?is plan 0 ! loss ( en]gy by induc$ curr5ts 9 ! lead cov]+s ( ! cables4 ,x 0 lat] decid$ to adopt ?ree-phase di/ribution at #aj1jjj volts = po9ts di/ant m ?an two miles f ! p[]-/ation4 ,ea* ?ree-phase circuit = ?is purpose 0 made up ( ?ree conductors sep>ately insulat$ & !n cov]$ ) a s+le lead %ea?1 s z to avoid losses ?r\gh induc$ curr5ts 9 ! latt]4 ,und]gr\nd & subm>9e cables = op]ation at high voltages are g5]ally cov]$ ) a cont9u\s lead %ea? & sometimes ) a spiral lay] ( galvaniz$ iron wire4 ,= high-voltage "w und]gr\nd ! lead cov]+ is g5]ally pref]r$ )\t iron wire1 b 9 subm>9e "w cov]+s ( bo? sorts are employ$4 ,! lead %ea? ( a cable be+ cont9u\s completely protects ! insulation f contact ) gases or liquids4 ,z ducts ( ei!r tile1 wood1 or iron =m a good me*anical protection = a cable1 ! r small /r5g? ( a lead %ea? is n a s]i\s objection 9 conduit "w4 ,subm>9e cables1 on ! o!r h&1 dep5d on _! own out] cov]+s = me*anical protection1 & may be expos$ to =ces t w\ld rapidly cut ?r\gh a lead %ea?4 ,cables = op]ation "u wat] %\ld usually be cov]$1 !re=e1 ) a lay] ( galvaniz$ iron wires outside ( ! lead %ea?4 ,^! wires are laid closely ab\t ! cable 9 spiral =m & are usually betwe5 #j4ab & #j4be in* 9 diamet] ea*1 dep5d+ on ! size ( ! cable & its location4 ,und]gr\nd conduits _c be reli$ on to exclude moi/ure & acids ( ! soil f ! cables :i* !y conta91 & ei!r ( ^! ag5ts may lead to de/ructive results4 ,if cables insulat$ ) rubb]1 b )\t a protect+ cov]+ outside ( x1 are laid 9 und]gr\nd conduits1 ! rubb] is apt to be rapidly de/roy$ by fluids & gases t f9d _! way into ! conduit4 ,if a pla9 lead-cov]$ cable is employ$ ! acids ( ! soil attack x1 & if /ray electric curr5ts f an electric railway f9d ! lead a conv5i5t conductor x is rapidly eat5 away :]e !y fl[ out ( x4 ,to avoid bo? ( ^! results ! und]gr\nd cable %\ld h a lead %ea?1 & ?is %ea? may be protect$ by an outside lay] ( hemp or jute treat$ ) asphaltum4 ,rubb]1 pap]1 & cotton are ext5sively us$ z insulation = und]gr\nd & subm>9e cables1 b ! ?ree are n usually employ$ toge!r4 ,z a rule1 ! insulation is appli$ sep>ately to ea* conductor1 & !n an additional lay] ( insulation may be locat$ ab\t ! gr\p ( conductors t g to make up ! cable4 ,:]e rubb] insulation is employ$1 a lead %ea? may or may n be add$1 b :]e insulation dep5ds on cotton or pap] ! out] cov]+ ( lead is absolutely necess>y to keep out moi/ure4 ,! radial ?ickness ( insulation on ea* conductor & ( t ab\t ! gr\p ( conductors 9 a cable %\ld v>y accord+ to ! voltage ( op]ation4 ,cables employ$ betwe5 ! g5]at+ & sub-/ations ( ! ,manhattan ,elevat$ ,railway1 to di/ribute ?ree-phase curr5t at #aa1jjj volts1 are ( ! ?ree-conductor type1 rubb] insulat$1 lead cov]$1 & laid 9 tile conduits4 ,ea* cable conta9s ?ree ,no4 #jjj /r&$ conductors1 & ea* conductor has its own insulation ( rubb]4 ,jute is laid on to give ! gr\p ( conductors an out] circul> =m1 & outside ( ! gr\p a lay] ( insulation & !n a lead %ea? is plac$4 ,outside diamet] ( ?is cable is ne>ly ?ree in*es1 & ! weight n9e p\nds p] l9e> foot4 ,! #aa1jjj-volt1 ?ree-phase curr5t f ,niag>a ,falls is di/ribut$ f ! t]m9al h\se to sev5 sub-/ations 9 ,buffalo ?r\gh ab\t #cj miles ( rubb]-insulat$ & #ah miles ( pap]-insulat$1 ?ree-conductor1 lead-cov]$ cables1 all 9 tile conduits4 ,9 ea* cable ! ?ree ,no4 #jjj /r&$ conductors are sep>ately insulat$ & !n twi/$ into a rope ) jute y>n laid 9 to give an ev5 r\nd surface = ! lead %ea? to re/ on4 ,a "p ( ! rubb]-insulat$ cables h ea* conductor cov]$ ) #i_/cb-;in* ( #cj p] c5t pure rubb] comp\nd1 & ! rema9+ rubb] cables h #h_/cb-;in* cov]+ on ea* conductor ( #dj p] c5t pure rubb] comp\nd4 ,! pap]-insulat$ cable has #ac_/fd-;in* ( pap] ar\nd ea* conductor1 & also ano!r #ac_/fd-;in* ( pap] cov]+ ab\t ! gr\p ( ?ree conductors & next to ! lead %ea?4 ,9 outside diamet] ! rubb]-insulat$ cable is #b-c_/h in*es1 & ( ! pap]-insulat$ cable #b-e_/h in*es1 ! radial ?ickness ( ! lead %ea? be+ #a_/h-;in* 9 ea* case4 ,x is report$ t ! cables insulat$ ) #i_/cb-;in* ( ! mixture1 said to be #cj p] c5t pure rubb]1 h prov$ to be m reliable ?an ! cables insulat$ ) #h_/cb-;in* ( a mixture said to be #dj p] c5t pure rubb]4 ,vol4 xviii41 ,a4 ,i4 ,e4 ,e41 #acf1 #hcf4 ,! six miles ( und]gr\nd cables t c>ry ?ree-phase1 #be1jjj-volt curr5t 9 ,/4 ,paul are ( ! ?ree-conductor type1 lead cov]$1 & laid 9 a tile conduit4 ,"o ( ! two ?ree-mile cables is insulat$ ) rubb] & ! o!r ) pap]4 ,9 ! =m] cable ea* conductor is sep>ately insulat$ ) a comp\nd conta9+ ab\t #ce p] c5t ( pure rubb] & hav+ a radial ?ickness ( #g_/cb-;in*4 ,! ?ree conductors aft] be+ insulat$ are laid up ) jute to give a r\nd surface1 tape be+ us$ to hold !m toge!r1 & !n a rubb] cov] #e_/cb-;in* ?ick is plac$ ab\t ! gr\p1 aft] :i* comes ! lead %ea? ov] all4 ,9 ! ?ree miles ( pap]-insulat$ cable ea* conductor is sep>ately cov]$ ) pap] to a ?ickness ( #i_/cb-;in*1 !n ! ?ree conductors are laid toge!r ) jute & tap$1 & next a lay] ( pap] #d_/cb-;in* ?ick is put on ov] ! gr\p4 ,outside ( all comes ! lead %ea?1 :i* has an out] coat+ ( t94 ,! pap] insulation 9 ^! cables 0 saturat$ ) a secret insulat+ comp\nd4 ,! lead %ea? on bo? ! rubb] & pap] insulat$ cables is #a_/h-;in* ?ick & ! %ea? ( ! =m] conta9s #c p] c5t ( t94 ,ea* ( ! ?ree conductors 9 ea* cable consi/s ( #g copp] /r&s & has an area ( #ff1jjj circul> mils4 ,outside ( ! lead %ea? ea* ( ^! cables has a diamet] ( ab\t #b-a_/d in*es4 ,by ! manufactur]'s contract ^! cables 7 te/$ up to #dj1jjj volts be=e %ipm5t1 & might be te/$ up to #cj1jjj volts 9 _! conduits dur+ any "t )9 five ye>s f _! pur*ase4 ,9 fir/ co/ ! cable ) rubb] insulation 0 said to be ab\t #ej p] c5t m exp5sive ?an ! cable 9 :i* pap] 0 us$4 ,vol4 xvii41 ,a4 ,i4 ,e4 ,e41 #fej4 ,und]gr\nd cables 9 :i* ! sep>ate conductors are cov]$ ) cotton braid treat$ ) an insulat+ comp\nd1 & !n ! gr\p ( conductors go+ to make up ! cable enclos$ 9 a lead %ea?1 are ext5sively us$ 9 ,au/ria & ,g]many4 ,= cables t op]ate at #aj1jjj to #ab1jjj volts ! radial ?ickness ( cotton insulation on ea* conductor is said to be )9 #c_/af-;in*1 & ^! cables are te/$ up to #be1jjj volts by plac+ all ( ! cable except its ends 9 wat]1 & !n connect+ "o end ( ! #be1jjj-volt circuit to ! wat] & ! o!r end to ! conductors ( ! cable4 ,a te/ on ! pap]-insulat$ cable at ,/4 ,paul %[$ its *>g+ curr5t to be #a4a amp]es at #be1jjj volts = ea* mile ( its l5g?4 ,= ! cable ) rubb] insulation ! *>g+ curr5t p] mile ( l5g? 0 f\nd to be ab\t twice z great z ! l curr5t = ! pap]-insulat$ cable4 ,ea* ( ! two ov]head transmission l9es connect$ ) ^! cables consi/$ ( ?ree solid copp] wires ) an area ( #ff1jjj circul> mils ea*1 & all ?ree s m\nt$ on ! poles z to =m ! corn]s ( an equilat]al triangle tw5ty-f\r in*es ap>t4 ,! *>g+ curr5t ( "o ( ^! ?ree-wire1 ov]head circuits 0 f\nd to be ab\t #j4ajc amp]e p] mile1 at #be1jjj volts1 or a little less ?an "o-t5? ( ! l curr5t = ! pap] cable4 ,^! te/s 7 made ) ?ree-phase curr5t ( sixty cycles p] second4 ,:]e ov]head transmission l9es jo9 und]gr\nd or subm>9e cables1 ei!r ) or )\t ! int]v5tion ( trans=m]s1 lightn+ arre/]s %\ld be provid$ to int]cept dis*>ges ( ?is sort t come ov] ! ov]head wires4 ,lightn+ arre/]s 7 provid$ 9 ! t]m9al h\se at ,buffalo1 :]e ! #bb1jjj-volt ov]head l9es fe$ ! #aa1jjj-volt cables ?r\gh trans=m]s1 also at ! t]m9al h\se 9 ,/4 ,paul1 :]e ! #be1jjj-volt ov]head l9es are electrically connect$ to ! und]gr\nd cables4 ,if an und]gr\nd or subm>9e cable connects two portions ( an ov]head l9e1 z 9 ! ,portsm\? & ,dov] transmission above m5tion$1 lightn+ arre/]s %\ld be provid$ at ea* end ( ! cable1 z 0 done 9 t case4 ,"o advantage ( a high r ?an a l[ voltage on und]gr\nd cables1 :]e p[] is to be transmitt$ at any giv5 rate1 lies 9 ! fact t ! amp]es fl[+ at a fault 9 ! cable det]m9e ! de/ructive effect !re1 r ?an ! voltage ( ! transmission4 ,x is report$ t a fault or %ort-circuit 9 "o ( ! #aa1jjj-volt cables at ,buffalo usually melts (f b little lead at ! %ea? & does n h en\gh explosive =ce to injure ! cable or its duct4 ,ozone seems to de/roy ! insulat+ prop]ties ( rubb] v rapidly1 & z x is well kn[n t ! sil5t electric dis*>ge f conductors at high voltages develops ozone1 c>e %\ld be tak5 to protect rubb] insulation f its action4 ,?is is especially true at ! ends ( cables :]e connections are made ) swit*es or o!r app>atus1 & ! rubb] insulation is expos$4 ,to protect ! rubb] at su* po9ts x is ! practice to sold] a brass cable head or t]m9al bell to ! lead %ea? ne> its end1 ?is head hav+ a diamet] p]haps twice z great z t ( ! %ea?1 & !n to fill ! space ab\t ! cable conductors 9 ?is head ) an insulat+ comp\nd4 ,heads ( ?is sort 7 us$ on ! #aa1jjj-volt cables at ,buffalo z well z on ! #ac1ejj-volt cable 9 ! ,portsm\? & ,dov] transmission4 ,z insulat+ mat]ials1 :e!r rubb]1 cotton1 or pap]1 may be impair$ or de/roy$ by heat1 x is necess>y t ! temp]ature ( und]gr\nd cables "u full load be kept )9 safe limits4 ,rubb] insulation c probably be rais$ to #abe or #aej ,fahr5heit )\t injury1 & pap] & cotton may g a little high]4 ,= a giv5 size & make ( lead$ cable ! rise ( temp]ature 9 its conductors above t ( ! surr\nd+ air1 = a giv5 loss 9 watts p] foot ( ! cable1 may be det]m9$ by computation or exp]im5t4 ,! next /ep is to f9d out h[ mu* ! temp]ature ( ! air 9 ! conduits :]e ! cable is to be us$ w rise above ! temp]ature ( ! e>? 9 :i* ! conduits are laid1 ) ! giv5 watt loss p] foot ( cable4 ,on ?is po9t !re are b little exp]im5tal data4 ,obvi\sly1 ! mat]ial ( :i* ducts are made1 ! numb] ( ducts gr\p$ toge!r ) cables op]at+ at ! same "t1 & ! ext5t to :i* ducts are v5tilat$ mu/ h an important be>+ on ?is "q4 ,at ,niag>a ,falls "s te/s 7 made to %[ ! rise ( air temp]ature 9 a section ( ?irty-six-duct conduit ly+ betwe5 two manholes ab\t #adj feet ap>t4 ,= ! purpose ( ?is te/ tw5ty-f\r ( ! ?irty-six ducts 9 ! conduit _h "o ,no4 #f draw+-9 wire pass$ ?r\gh ea* ( !m4 ,^! tw5ty-f\r wires 7 connect$ into ?ree gr\ps ( eight wires ea*1 s t "o gr\p 0 all 9 ducts next to ! surr\nd+ e>?1 ano!r gr\p 0 "o-half 9 ducts next to ! e>? & ! o!r half 9 ducts sep>at$ f ! e>? by at lea/ "o duct1 :ile ! ?ird gr\p ( wires 0 entirely 9 ducts sep>at$ f ! e>? by at lea/ "o duct4 ,x 0 f\nd t :5 en\gh curr5t 0 s5t ?r\gh ^! wires to repres5t a loss ( #e4e watts p] foot ( ducts 9 :i* !y 7 locat$1 ! rise ( temp]ature 9 ! air ( ! ducts next to ! e>? 0 ab\t #ajh ,fahr5heit above t ( ! e>?4 ,= ! ducts sep>at$ f ! e>? by at lea/ "o o!r duct ! rise 9 temp]ature ( conta9$ air 0 #add ,fahr5heit above ! e>?4 ,if ! e>? ab\t ! ducts rea*$ #gj 9 hot wea!r1 ! temp]ature ( air 9 ! inn] ducts1 ) a loss ( #e4e watts p] duct foot1 w\ld ?us be #bad4 ,?is temp]ature is too high = ei!r rubb]1 cotton1 or pap] insulation1 to say no?+ ( ! am\nt by :i* ! temp]ature ( ! conductors & insulation ( a cable 9 op]ation mu/ exce$ t ( ! surr\nd+ air 9 its duct4 ,! cables actually in/all$ 9 ! ducts j consid]$ 7 design$ = a loss ( #b4cd watts p] foot4 ,z ! ,no4 #f wire us$ 9 ! te/ did n ne>ly fill ea* duct z a cable w\ld d1 x w\ld be v int]e/+ to "k h[ mu* v5tilation took place :ile ! te/ 0 go+ on4 ,un=tunately1 ?is po9t 0 n report$4 ,vol4 xviii41 ,a4 ,i4 ,e4 ,e41 #ejh4 ,,*apt] ,,xv4 ,,mat]ials ,,= ,,l9e ,,conductors4 ,copp]1 alum9um1 iron1 & bronze are all us$ = conductors 9 long-di/ance electric transmissions1 b copp] is ! /&>d metal = ! purpose4 ,an ideal conductor = transmission l9es %\ld comb9e ! be/ electrical conductivity1 great t5sile /r5g?1 a high melt+ po9t1 l[ coeffici5t ( expansion1 h>dness1 & great resi/ance to oxidation4 ,no "o ( ! metals nam$ possesses all ( ^! prop]ties 9 ! highe/ degree1 & ! problem is to select ! mat]ial be/ suit$ to ea* case4 ,alum9um suff]s v slightly by exposure to ! wea!r1 copp] & bronze suff] a little m1 :ile iron & /eel wire are attack$ s]i\sly by ru/4 ,iron1 copp]1 & bronze are all s h>d t little or no tr\ble has occurr$ f wires ( ^! metals cutt+ or we>+ away at ! po9ts ( atta*m5t to insulators4 ,alum9um1 on ! o!r h&1 is s s(t t sway+ ( ! wire may1 9 "t1 cause mat]ial we> at ! supports1 or x may be cut by tie wires4 ,b l9es ( alum9um wire h n be5 9 use long en\gh to det]m9e h[ mu* tr\ble is to be expect$ f its lack ( h>dness4 ,a small coeffici5t ( expansion is desirable 9 transmission wires1 because ! /ra9 on ! wire itself & on its supports v>ies rapidly ) ! am\nt ( v]tical deflection ( ea* span1 becom+ great] z ! deflection decreases4 ,tak+ ! expansion ( copp] z unity1 t ( alum9um is #a4d2 ( bronze1 #a4a2 & ( iron & /eel1 #j4g4 ,f ^! figures x foll[s t iron & /eel wires %[ ! lea/ v>iation 9 ! am\nt ( sag betwe5 supports1 & alum9um wire %[s ! mo/4 ,wr\ght iron melts at ab\t #b1hjj1 /eel at #b1gjj1 copp] at #a1ibi1 bronze at ab\t ! same po9t z copp]1 & alum9um at #a1aeg ,fahr5heit4 ,?is l[ melt+ po9t ( alum9um may prove a s\rce ( tr\ble by op5+ a l9e ( t mat]ial :]e "s =eign wire falls on x4 ,?is1 accord+ to a report1 0 illu/rat$ at a sub-/ation on a #cj1jjj-volt transmission l9e :]e a de/ructive arc 0 />t$ at ! swit*bo>d4 ,n be+ able to ext+ui% ! arc 9 any o!r way1 a l9eman ?rew an iron wire across ! alum9um l9es j outside ( ! sub-/ation1 & ^! l9es 7 imm$iately melt$ ?r\gh by ! iron wire1 ?us op5+ ! circuit4 ,! tr\ble may h w>rant$ s desp]ate a rem$y 9 ?is case2 b1 z a rule1 x does n pay to cut a transmission l9e 9 ord] to get rid ( a %ort circuit4 ,9 ! ord9>y con/ruction ( transmission l9es on l& ! t5sile /r5g? ( wire is second>y 9 importance to its electrical conductivity1 because supports c be spac$ accord+ to ! /r5g? ( ! conductor us$4 ,:5 l>ge bodies ( wat] mu/ be cross$1 t5sile /r5g? is a prime requirem5t4 ,?us a #adb-mile l9e f ,colgate to ,oakl&1 9 ,cali=nia1 crosses ! ,/raits ( ,c>qu9ez 9 ! =m ( /eel cables1 ea* sev5-eigh?s ( an in* 9 diamet] & #d1dbg feet long4 ,/eel wire 0 select$ = ?is long span1 probably because x c be giv5 a great] t5sile /r5g? ?an t ( any o!r metal4 ,anneal$ iron wire has a t5sile /r5g? betwe5 #ej1jjj & #fj1jjj p\nds p] squ>e in*4 ,/eel wires v>y all ! way f #ej1jjj to m ?an #cej1jjj p\nds p] squ>e in* 9 /r5g?1 b mild /eel wire ) a /r5g? rang+ f #hj1jjj to #ajj1jjj p\nds p] squ>e in* is readily obta9$4 ,s(t copp] %[s a t5sile /r5g? betwe5 #cb1jjj & #cf1jjj p\nds p] squ>e in*1 & h>d-drawn copp] betwe5 #de1jjj & #gj1jjj p\nds1 dep5d+ on ! degree ( h>dness4 ,silicon-bronze wires v>y 9 /r5g? f less ?an #fj1jjj to m ?an #ajj1jjj p\nds p] squ>e in*1 & phosphor-bronze has a t5sile /r5g? ( ab\t #ajj1jjj p\nds4 ,bronze wires1 l ^? ( mo/ alloys1 %[ a mu* wid] range ( /r5g? ?an ^? ( iron or copp]4 ,9 silicon-bronze wire ! electrical conductivity decreases z ! t5sile /r5g? increases4 ,! t5sile /r5g? ( alum9um wire is l[] ?an t ( any o!r us$ 9 transmission l9es1 be+ only ab\t #cj1jjj p\nds p] squ>e in*4 ,solid alum9um wires ( l>ge size h giv5 tr\ble by break+ "u /ra9s well )9 _! nom9al /r5g?1 due probably to imp]fections or twi/s4 ,?is tr\ble is n[ g5]ally avoid$ by ! use ( alum9um cables4 ,9 t mo/ necess>y prop]ty ( a transmission l9e--conductivity--copp] excels all o!r metals except silv]4 ,tak+ ! conductivity ( s(t copp] wire at #ajj1 ! conductivity ( h>d-drawn copp] is #ih2 t ( silicon-bronze ranges f #df to #ih2 t ( alum9um is #fj2 ( phosphor-bronze1 #bf2 ( anneal$ iron wire1 #ad2 & ( /eel wire ( #ajj1jjj p\nds t5sile /r5g? p] squ>e in*1 #aa4 ,copp] wire1 bo? s(t & h>d1 z regul>ly made1 does n v>y m ?an "o p] c5t f ! /&>d1 & alum9um & anneal$ iron wires also %[ high uni=mity z to resi/ance4 ,silicon-bronze & /eel wires1 on ! o!r h&1 fluctuate mu* 9 electrical conductivity4 ,= any p>ticul> transmission l9e ! resi/ance is usually det]m9$ by consid]ations ap>t f ! metal to be us$ z a conductor1 s t a l9e ( giv5 resi/ance or conductivity mu/ be con/ruct$ ( t mat]ial :i* be/ con=ms to ! requirem5ts z to size ( wire1 weight1 /r5g?1 & co/4 ,all[+ ! weight ( any def9ite mass ( copp] to repres5t unity1 ! weight ( an equal mass ( wr\ght iron is #j4hg2 ( /eel1 #j4hi2 ( alum9um1 #j4cj2 :ile t ( bronze is v ne>ly equal to t ( ! copp]4 ,! smalle/ l9e wire t c be us$ = a giv5 l5g? & resi/ance is "o ( pure1 s(t copp]4 ,next 9 cross-sectional area come h>d-drawn copp] & "s silicon-bronze1 ei!r ( :i* ne$ be only two p] c5t l>g] ?an ! s(t copp] = an equal resi/ance4 ,"s o!r silicon-bronze wire ( great] t5sile /r5g? p] squ>e in* w\ld require a sectional area ( #b4ag times t ( ! s(t copp]4 ,alum9um wire ) #fj p] c5t ( ! conductivity ( copp] requires #a4ff ( its section = wires ( equal resi/ance4 ,z phosphor-bronze has only #bf p] c5t ( ! conductivity ( copp]1 ! section ( ! bronze mu/ be #c4hd times t ( ! copp] wire if _! l5g?s & resi/ance are to be equal4 ,an anneal$ iron wire is equal 9 resi/ance to a copp] wire ( ! same l5g? :5 ! iron has #g4ad times ! section ( ! copp]4 ,/eel1 ) #aa p] c5t ( ! conductivity ( copp]1 mu/ h #i4ji times ! copp] section 9 ord] t wires ( ! same l5g? may h equal resi/ances4 ,x is n desirable to use a copp] wire small] ?an ,no4 #d ,b4 ,s4 gauge = transmission l9es1 because ( ! lack ( t5sile /r5g? 9 small] sizes4 ,:5 ! conductivity ( a copp] wire small] ?an ,no4 #d is ample1 an iron wire w give ! requir$ conductivity1 ) a /r5g? f> great] ?an t ( ! copp]4 ,= a l9e ( giv5 l5g? & conductivity ( any o!r metal ! weight comp>$ ) t ( a copp] l9e is repres5t$ by ! product ( ! figures = relative section ( ! two l9es & ( ! weight ( unit mass ( ! metal 9 "q comp>$ ) t ( copp]4 ,?us1 = ! same conductivity ! weight ( a c]ta9 l5g? ( iron wire is #j4hg #g4ad #f4ba times ! weight ( a copp] wire4 ,= ! /eel wire above nam$ ! weight is #j4hi #i4ji #h4ji times t ( a copp] l9e ( equal conductivity4 ,phosphor-bronze 9 a l9e ( giv5 l5g? & resi/ance has #c4hd times ! weight ( s(t copp]4 ,silicon-bronze = a transmission l9e mu/ weigh f #a4jb to #b4ag times z mu* z s(t copp] = a giv5 l5g? & conductivity4 ,alum9um = a l9e ( fix$ l5g? & conductivity w weigh #a4ff #j4c #j4e times z mu* z copp]4 ,= a l9e ( fix$ l5g? & resi/ance1 h>d-drawn copp] w weigh ab\t two p] c5t m ?an s(t copp]4 ,tak+ ! t5sile /r5g? ( s(t copp] at #cd1jjj p\nds p] squ>e in*1 h>d-drawn copp] at #de1jjj to #gj1jjj1 silicon-bronze at #fj1jjj to #ajj1jjj1 phosphor-bronze at #ajj1jjj1 iron at #ee1jjj1 /eel at #ajj1jjj1 & alum9um at #cj1jjj p\nds1 ! relative /r5g?s ( wires ) equal sectional areas comp>$ ) ! s(t copp] are1 = h>d-drawn copp]1 #a4cb to #b4jf2 silicon-bronze1 #a4gf to #b4id2 phosphor-bronze1 #b4id2 iron1 #a4fb2 /eel1 #b4id2 & = alum9um1 #j4hh4 ,comp>+ wires on ! basis ( equal resi/ances = equal l5g?s1 ) s(t copp] aga9 ! /&>d1 ! t5sile /r5g? ( ea* z to x is z foll[s3 ,a h>d-drawn copp] l9e has #a4jb #a4cb #a4cd to #a4jb #b4jf #b4aj times ! /r5g? ( a l9e ( s(t copp]4 ,) silicon-bronze ! /r5g? ( l9e wire w\ld range betwe5 #a4jb #a4gf #a4gi & #b4ag #b4id #f4ch times t ( copp]4 ,iron w\ld give ! l9e a /r5g? z to s(t copp] repres5t$ by #g4ad #a4fb #aa4ef4 ,/eel ( #ajj1jjj p\nds t5sile /r5g? p] squ>e in* w give a l9e #i4ji #b4id #bf4gj times z /rong z x w\ld be if compos$ ( s(t copp]4 ,) alum9um ! /r5g? ( ! l9e w\ld be #a4ff #j4hh #a4df times t ( copp]4 ,= phosphor-bronze ! figures are #c4hd #b4id #aa4bi4 ,f ! =ego+ x may be %[n h[ _m times ! price ( s(t copp] p] p\nd may be paid = ea* ( ! o!r metals to =m a l9e ( giv5 l5g? & resi/ance at a co/ equal to t ( a s(t copp] l9e4 ,^! prices p] p\nd = ! sev]al metals relative to t ( s(t copp] are z foll[s3 ,tak+ ! price ( s(t copp] z "o1 ! price = h>d-drawn copp] mu/ be #a #a4jb #j4ih4 ,= silicon-bronze ! price may be z high z #a #a4jb #j4ih1 or z l[ z #a #b4ag #j4df ( ! price ( s(t copp] wire4 ,phosphor-bronze may h a price repres5t$ by only #a #c4hd #j4bf t ( copp]4 ,! price ( iron wire %\ld be #a #f4ba #j4af ( t ( copp]1 & = /eel wire ( ! quality /at$ ! price c only be #a #h4ja #j4ab4 ,alum9um wire alone may h a high] price p] p\nd ?an s(t copp] = ! same resi/ance & co/ ( l9e1 ! figure = ! relative co/ ( ?is metal be+ #a #j4e #b4 ,f ! =ego+ x appe>s t = a l9e ( giv5 co/1 l5g?1 & resi/ance1 s(t copp] has ! lea/ cross-section & t5sile /r5g?2 /eel1 ! greate/ cross-section1 weight1 t5sile /r5g?1 & l[e/ p]missible price p] p\nd2 & alum9um1 ! lea/ weight & highe/ price p] p\nd4 ,,relative ,,prop]ties ,,( ,,wires ,,hav+ ,,equal ,,l5g?s ,,& ,,resi/ances4 ---------------------------------------- ----------------- ,relative ,relative ,relative ,relative ,metal 9 ,wire4 ,cross ,weights4 ,t5sile ,prices p] ,sections4 ,/r5g?s4,p\nd = ,same ,total ,co/4 ---------------------------------------- ----------------- ,s(t ,copp] #a4jj #a4jj #a4 #a4jj ,h>d ,copp] #a4jb #a4jd #a4cd 4#ih ,v ,h>d ,copp] #a4jb #a4jb #b4aj 4#ih ,no4 #a ,silicon-,bronze #a4jb #a4jb #a4gi 4#ih ,no4 #b ,silicon-,bronze #b4ag #b4ag #f4ch 4#df ,alum9um #a4ff 4#ej #a4df #b4jj ,phosphor-,bronze #c4hd #c4hd #aa4bi 4#bf ,anneal$ ,iron #g4ad #f4ba #aa4ef 4#af ,mild ,/eel #i4ji #h4ji #bf4gj 4#ab ---------------------------------------- ----------------- ,! relative cross sections & weights ( bo? iron & /eel wires are s great z to prev5t _! g5]al use because ( ! labor & co/ ( _! erection4 ,s f> z ! fir/ co/ ( ! wire alone is conc]n$1 iron may be approximately equal to copp] 9 "s metal m>kets4 ,! only practical place = an iron wire1 h[ev]1 is "o :]e copp] w\ld be too small or n /rong en\gh4 ,/eel wire f9ds a place1 9 spite ( its high resi/ance1 9 ^? exceptional cases :]e a s+le span ( sev]al ?\s& feet mu/ be made1 requir+ high t5sile /r5g?4 ,9 su* cases x is usually bett] to give ! /eel span a great] resi/ance ?an an equal l5g? ( ! ma9 portion ( ! l9e1 s z to avoid excessive size & weight ( ! span4 ,ev5 :5 ?is is done ! resi/ance ( ! /eel span w\ld be v small comp>$ ) t ( a long transmission l9e4 ,phosphor-bronze f9ds little use z conductors 9 transmission sy/ems because ( its relatively high electrical resi/ance4 ,if great t5sile /r5g? is want$1 iron or /eel w supply x at a fraction ( ! co/ ( phosphor-bronze4 ,z a conductor simply1 phosphor-bronze is wor? only #j4bf z mu* p] p\nd z s(t copp]1 :ile its actual m>ket price is great] ?an t ( copp]4 ,silicon-bronze ( relatively high resi/ance1 requir+ #b4ag times ! section & weight ( copp] = equal conductivity1 is entitl$ to little or no consid]ation z a transmission l9e mat]ial4 ,?is alloy1 9 ord] to give equal conductivity at equal co/ ) copp]1 mu/ sell at only #j4df ( ! price ( copp] p] p\nd4 ,b ! price ( silicon-bronze is equal to1 or great] ?an1 ! price ( copp]1 s t ! co/ ( ! high-resi/ance silicon-bronze = a l9e ( giv5 resi/ance w be m ?an twice t ( copp]4 ,= ?is m ?an d\ble co/ ! bronze gives #f4ch times ! t5sile /r5g? ( a s(t copp] l9e ( equal conductivity4 ,tak+ ! m>ket price ( /eel at "o-fif? t ( copp]1 :i* is amply high = ! /eel1 z a rule1 a /eel wire ( equal conductivity ) ! copp] w co/ only #a4f times z mu* & w h #bf4g times ! t5sile /r5g? ( ! copp]1 or f\r times ! t5sile /r5g? ( a wire ( equal conductivity made f ! high-resi/ance silicon-bronze4 ,f ?is x is cle> t /eel (f]s a *eap] comb9ation ( conductivity & /r5g? ?an does silicon-bronze ( high resi/ance4 ,t grade ( silicon-bronze hav+ ! l[e/ resi/ance may co/ #j4ih z mu* p] p\nd z s(t copp]1 & w h #a4gi times ! /r5g? ( ! copp] = equal conductivity4 ,?is bronze actually co/s m p] p\nd ?an copp]1 s t x _c give equal conductivity at equal co/4 ,v h>d-drawn copp] has a conductivity equal to t ( ! be/ silicon-bronze1 & ! t5sile /r5g? ( ?is copp] is sev5te5 p] c5t great] ?an t ( ! bronze4 ,silicon-bronze co/s m p] p\nd ?an h>d copp]1 b ev5 ) equal prices ! h>d copp] gives equal conductivity & high] /r5g? at ! same co/4 ,fur!rmore1 ! conductivity ( silicon-bronze is mu* m liable to s]i\s v>iations ?an t ( h>d copp]4 ,betwe5 h>d-drawn copp] & /eel !re is v little app>5t place = any grade ( bronze 9 electric transmission l9es4 ,! h>de/ copp] wire is v /iff1 & is m liable to crack :5 twi/$ or b5t ?an is wire ( only m$ium h>dness4 ,su* m$ium-h>d copp] has a t5sile /r5g? ( ?irty-f\r p] c5t great] ?an s(t copp] ( equal conductivity1 & is mu* us$ on long transmission l9es4 ,alum9um is ! only metal :i*1 = giv5 conductivity 9 a transmission l9e1 comb9es a small] weight1 a great] t5sile /r5g?1 & a high] p]missible price ?an s(t copp] = ! same total co/4 ,= equal conductivity an alum9um wire has a great] t5sile /r5g? ?an "o ( m$ium-h>d copp]1 & co/s less ?an copp] ( any grade :5 ! price p] p\nd ( ! alum9um is less ?an twice t ( copp]1 :i* is usually ! case4 ,^! prop]ties make alum9um by f> ! mo/ important competitor ( copp] 9 electric transmission & h l$ to its use 9 a numb] ( cases1 notably = ! two longe/ l9es 9 ! _w1 namely1 betwe5 ,colgate & ,oakl& & betwe5 ,electra & ,san ,francisco1 9 ,cali=nia4 ,x has n be5 f\nd practicable to sold] jo9ts 9 alum9um wires because ( ! result+ electrolytic action :5 alum9um is 9 contact ) o!r metals4 ,jo9ts ( alum9um wires are usually made by slipp+ ! ends pa/ ea* o!r 9 an oval alum9um sleeve & !n giv+ ! sleeve & wires two or ?ree complete twi/s1 or by a process ( cold weld+ ) a sleeve jo9t4 ,long transmission l9es are 9 ne>ly all cases run ) b>e wire support$ by poles4 ,:]e v high voltages are employ$ no insulation t c be put on ! wire w make x safe to h&le1 & ! co/ ( su* insulation w\ld add mat]ially to t ( ! entire l9e4 ,x is1 !re=e1 ! practice to run transmission l9es above all o!r wires & to rely entirely on ! supports = insulation4 ,! consid]ations ?us f> not$ apply alike to wires c>ry+ cont9u\s & alt]nat+ curr5ts1 b !re are "s o!r factors t apply solely to alt]nat+ l9es4 ,ow+ to ! inductive effects ( alt]nat+ curr5ts 9 long1 p>allel wires1 su* wires %\ld be transpos$ betwe5 _! supports at frequ5t int]vals4 ,! induction betwe5 wires increases ) ! frequ5cy ( ! curr5t c>ri$1 & decreases ) ! di/ance betwe5 ! wires4 ,accord+ to ^! conditions1 wires %\ld be transpos$ z (t5 z e eigh? ( a mile 9 "s cases1 & at int]vals ( "o mile or m 9 o!rs4 ,an alt]nat+ curr5t :5 pass+ along a l9e t5ds to conc5trate itself 9 ! out] lay]s ( ! wire1 leav+ ! c5tre idle4 ,?is unequal curr5t di/ribution increases ) ! frequ5cy ( ! curr5t & ) ! area ( ! cross section ( ! wire4 ,! practical effect ( ?is unequal di/ribution is to make ! resi/ance ( a wire a little high] = alt]nat+ ?an = cont9u\s curr5ts4 ,9 exi/+ transmission l9es ! increase ( resi/ance due to ?is cause seldom am\nts to "o p] c5t4 ,:5 an alt]nat+ curr5t passes ?r\gh a circuit1 ! action t]m$ self-induction sets up an electromotive =ce 9 ! circuit t opposes ! fl[ ( curr5t1 z does ! resi/ance ( ! wire1 & ?is is call$ ! inductance ( ! circuit4 ,! ratio ( ?is inductance to ! resi/ance ( a circuit increases ) ! numb] ( p]iods p] second ( ! alt]nat+ curr5t us$ & ) ! sectional area ( ! wires compos+ ! circuit4 ,= a circuit ( ,no4 #f ,b4 ,s4 gauge wire ! inductance am\nts to only five p] c5t ( ! l9e resi/ance1 b = a circuit ( ,no4 #jjj wire ! inductance consumes z mu* ( ! appli$ voltage z does ! resi/ance1 ) #fj-;cycle curr5t4 ,bo? ! unequal di/ribution ( alt]nat+ curr5t ov] ! cross-section ( a conductor & ! inductance ( circuits make x desirable to keep ! diamet]s ( transmission wires z small z o!r consid]ations p]mit4 ,z s(t copp] has great] conductivity p] unit ( area ?an any ( ! o!r available metals1 x cle>ly has an advantage ov] all ( !m z to inductance & increase ( resi/ance ) alt]nat+ curr5t4 ,at v high voltages !re is an important leakage ( en]gy betwe5 ! conductors ( a circuit1 & ?is loss v>ies inv]sely ) ! di/ance betwe5 ^! conductors4 ,?us x happ5s t inductance makes x desirable to br+ ! p>allel wires ( a circuit close toge!r1 :ile ! leakage ( en]gy f wire to wire makes x desirable to c>ry !m f> ap>t4 ,to provide great] security f int]ruption1 ! conductors = important transmissions are 9 "s cases c>ri$ on two indep5d5t pole l9es4 ,ev5 :]e all ! conductors are on a s+le l9e ( poles x is frequ5t practice to divide !m up into a numb] ( comp>atively small wires1 & ?is decreases inductance4 ,data ( a numb] ( transmission l9es pres5t$ 9 ! app5d$ table illu/rate ! practice 9 "s ( ! m rec5t & important cases z to ! mat]ials1 size1 numb]1 & arrangem5t ( ! wires4 ,! plants ( :i* p>ticul>s are giv5 include ! greate/ p[] capacities1 ! longe/ di/ances1 & ! highe/ voltages n[ involv$ 9 electrical transmissions4 ,ea* ( ! l9es nam$ is work$ ) alt]nat+ curr5t ( two- or ?ree-phase4 ,ea* ?ree-phase l9e mu/ h at lea/ ?ree wires1 & ea* two-phase l9e usually has f\r wires4 ,on t5 ( ! l9es ! numb] ( wires is great] ?an ?ree or f\r1 ?us r$uc+ ! necess>y size ( ea* wire = a giv5 conductivity ( ! l9e4 ,! ,butte1 ,oakl&1 & ,hamilton l9es are run on two sets ( poles = great] security1 & a second pole l9e has be5 add$ to ! ,niag>a & ,buffalo sy/em to c>ry additional wires4 ,! l>ge/ wire us$ 9 any ( ^! l9es is ! alum9um cable ( #ejj1jjj circul> mils betwe5 ,niag>a ,falls & ,buffalo4 ,?is cable has #a4ff times ! area 9 cross section ( a copp] cable ( equal conductivity4 ,,sizes ,,& ,,mat]ials ,,( ,,wires ,,on ,,"s ,,am]ican ,,transmission ,,l9es4 ---------------------------------------- ----------------------- ,l5g? ,numb] ,size ( ( ,location ( ,transmission4 ,l9e,wires4 ,ea* ,wire,metal 9,trans- - -- ,b4 ,s4 ,wire4 mis- ,volt- ,gauge4 sion4 age4 ,miles4 ---------------------------------------- ----------------------- ,caon ,f]ry to ,butte #ej1jjjf #j ,copp] #fe ,colgate to ,oakl& #dj1jjjc #jj ,copp] #adb #c #jjj ,alum9um#adb ,electra to ,san ,francisco #dj1jjjcdga1jcd ,c4 ,m4 #adg ,santa ,ana ,r4 to ,los ,angeles #cc1jjjf #a ,copp] #hc ,apple ,riv] to ,/4 ,paul #be1jjjf #b #be ,well& ,canal to ,hamilton #bb1ejjc #a #ce #c #jj #cg ,caon ,city to ,cripple ,creek #bj1jjjc #c #bc-a_/b ,madrid to ,bl& #bj1jjjf #d #cb ,:ite ,riv] to ,dales #bb1jjjc #f #bg ,ogd5 to ,salt ,lake ,city #af1jjjf #a #cf-a_/b ,san ,gabriel ,caon to ,los ,angeles #af1jjjf #e #bc ,to ,victor1 ,col #ab1fjjc #d #h ,niag>a ,falls to ,buffalo #bb1jjjfcej1jjj ,c4 ,m4 #bc #bb1jjjcejj1jjj ,c4 ,m4,alum9um #bj ,yadk9 ,riv] to ,salem #ab1jjjc #a ,copp] #ad4e ,f>m+ton ,riv'r to ,h>t=d#aj1jjjcccf1dbj ,c4 ,m4,alum9um #aa ,wilbraham to ,ludl[ ,mills #aa1ejjface1bdg ,c4 ,m4 #d4e ,niag>a ,falls to ,toronto #fj1jjjfaij1jjj ,c4 ,m4 ,copp] #ge ---------------------------------------- ----------------------- ,alum9um l9es are n[ employ$ = ! ?ree longe/ electrical transmissions 9 ,nor? ,am]ica4 ,9 ! longe/ s+le l9e1 t f ,electra p[]-h\se to ,san ,francisco1 a di/ance ( #adg miles1 alum9um is ! conductor us$4 ,! #adb-mile transmission betwe5 ,colgate & ,oakl& is c>ri$ out ) ?ree alum9um & ?ree copp] l9e wires4 ,= ! ?ird transmission 9 po9t ( l5g?1 t f ,%aw9igan ,falls to ,montreal1 a di/ance ( #he miles1 ?ree alum9um conductors are employ$4 ,! ?ree transmissions j nam$ h unusually l>ge capacities z well z sup]lative l5g?s1 ! g5]ators 9 ! ,electra plant be+ rat$ at #aj1jjj1 9 ! ,colgate plant at #aa1bej1 & 9 ! ,%aw9igan plant at #g1ejj kil[atts4 ,weight & co/ ( su* l9es are v l>ge4 ,= ! ?ree ,no4 #jjjj alum9um conductors1 #adb miles ea* 9 l5g?1 betwe5 ,colgate & ,oakl&1 ! total weight mu/ be ab\t #ddj1jfg p\nds1 co/+ #acb1jbj at #cj c5ts p] p\nd4 ,betwe5 ,electra & ,mission ,san ,jos1 :]e ! l9e bran*es1 is #ajj miles ( ! #adg-mile transmission f ,electra to ,san ,francisco4 ,on ! ,electra & ,mission ,san ,jos section ! alum9um conductors comprise ?ree /r&$ cables ( #dga1jcd circul> mils ea* 9 sectional area & ) a total weight ( ab\t #gba1bjj p\nds4 ,?is section alone ( ! l9e 9 "q w\ld h co/ #baf1cfj at #cj c5ts p] p\nd4 ,! #he-mile alum9um l9e f ,%aw9igan ,falls to ,montreal is made up ( ?ree-/r&$ conductors ea* ) a sectional area ( #ahc1gjh circul> mils4 ,all ?ree conductors h a comb9$ weight ( ab\t #bbe1cjj p\nds1 & at #cj c5ts p] p\nd w\ld h co/ #fg1eij4 ,alum9um l9es are n conf9$ to new transmissions1 b are also f\nd 9 additions to ^? :]e copp] conductors 7 at fir/ us$4 ,?us1 ! ?ird transmission circuit betwe5 ! p[]-h\se at ,niag>a ,falls & ! t]m9al h\se 9 ,buffalo1 a di/ance ( #bj miles by ! new pole l9e1 0 =m$ ( ?ree alum9um cables ea* ) an area ( #ejj1jjj circul> mils1 ?\gh ! six conductors ( ! two previ\s circuits 7 ea* #cej1jjj circul> mils copp]4 ,f ^! examples x may be se5 t copp] has lo/ its =m] place z ! only conductor to be s]i\sly consid]$ = transmission circuits4 ,alum9um has n only disput$ ?is claim = copp]1 b has actually ga9$ ! mo/ conspicu\s place 9 long transmission l9es4 ,?is victory ( alum9um has be5 won 9 h>d competition4 ,! decisive factor has be5 t ( co/ = a circuit ( giv5 l5g? & resi/ance4 ,f ! /&po9t ( cross-sectional area alum9um is inf]ior to copp] z an electrical conductor4 ,comp>+ wires ( equal sizes & l5g?s1 ! alum9um h only sixty p] c5t ( ! conductivity ( ! copp]1 s t an alum9um wire mu/ h #a4ff times ! sectional area ( a copp] wire ( ! same l5g? 9 ord] to (f] an equal electrical resi/ance4 ,z r\nd wires v>y 9 sectional areas ) ! squ>es ( _! diamet]s1 an alum9um wire mu/ h a diamet] #a4bh times t ( a copp] wire ( equal l5g? 9 ord] to (f] ! same conductivity4 ,! inf]iority ( alum9um z an electrical conductor 9 t]ms ( sectional area is m ?an (fset by its sup]iority ov] copp] 9 t]ms ( weight4 ,"o p\nd ( alum9um drawn into a wire ( any l5g? w h a sectional area #c4cc times z great z "o p\nd ( copp] 9 a wire ( equal l5g?4 ,?is foll[s f ! fact t ! weight ( copp] is #eee p\nds :ile t ( alum9um is only #afg p\nds p] cubic foot1 s t = equal weights ! bulk ( ! latt] is #c4cc times t ( ! =m] metal4 ,z ! alum9um wire has equal l5g? ) & #c4cc times ! sectional area ( ! copp] wire ( ! same weight1 ! electrical conductivity ( ! =m] is #c4cc #a4ff #b times t ( ! latt]4 ,h5ce1 = equal resi/ances1 ! weight ( an alum9um is only "o-half z great z t ( a copp] wire ( ! same l5g?4 ,f ?is fact x is evid5t t :5 ! price p] p\nd ( alum9um is any?+ less ?an twice ! price ( copp]1 ! =m] is ! *eap] metal = a transmission l9e ( any requir$ l5g? & electrical resi/ance4 ,! t5sile /r5g? ( bo? s(t copp] & ( alum9um wire is ab\t #cc1jjj p\nds p] squ>e in* ( section4 ,= wires ( equal l5g? & resi/ance ! alum9um is !re=e sixty-six p] c5t /rong] because its area is sixty-six p] c5t great] ?an t ( a s(t copp] wire4 ,m$ium h>d-drawn copp] wire su* z is mo/ commonly us$ = transmission l9es has a t5sile /r5g? ( ab\t #de1jjj p\nds p] squ>e in*1 b ev5 comp>$ ) ?is grade ( copp] ! alum9um wire ( equal l5g? & resi/ance has ! advantage 9 t5sile /r5g?4 ,:ile ! alum9um l9e is ?us /rong] ?an an equival5t "o ( copp]1 ! weight ( ! =m] is only "o-half t ( ! latt]1 s t ! di/ance betwe5 poles may be increas$1 or ! sizes ( poles1 cross-arms1 & p9s decreas$ ) alum9um wires4 ,9 "o respect ! /ra9 on poles t c>ry alum9um may be great] ?an t on poles ) equival5t copp] l9es1 namely1 9 t ( w9d pressure4 ,a w9d t bl[s 9 a direction o!r ?an p>allel ) a transmission l9e t5ds to break ! poles at ! gr\nd & pro/rate ! l9e 9 a direction at "r angles to its c\rse4 ,! total w9d pressure 9 any case is obvi\sly proportional to ! ext5t ( ! surface on :i* x acts1 & ?is surface is measur$ by "o-half ( ! ext]nal area ( all ! poles & wires 9 a giv5 l5g? ( l9e4 ,z ! alum9um wire mu/ h a diamet] tw5ty-eight p] c5t great] ?an t ( copp] wire ( equal l5g?1 "o-half ( ! total wire surface w also be tw5ty-eight p] c5t great] = ! =m] metal4 ,?is c>ries ) x an increase ( tw5ty-eight p] c5t 9 t portion ( ! w9d pressure due to wire surface4 ,9 good practice ! numb] ( transmission wires p] pole l9e is (t5 only ?ree1 & seldom m ?an six1 s t ! surface areas ( ^! wires may be no great] ?an t ( ! poles4 ,x foll[s t ! increase ( tw5ty-eight p] c5t 9 ! surface ( wires may correspond to a mu* small] p]c5tage ( increase = ! entire area expos$ to w9d pressure4 ,su* small diff]5ce z exi/s betwe5 ! total w9d pressures on alum9um & copp] l9es ( equal conductivity is ( slight importance 9 view ( ! g5]al practice by :i* "s /raight z well z ! curv$ portions ( transmission l9es are n[ secur$ by guys or /ruts at "r angles to ! direction ( ! wires4 ,vibration ( transmission l9es & ! consequ5t t5d5cy ( cross-arms1 p9s1 insulators1 & ( ! wires to "w loose is less ) alum9um ?an ) copp] conductors z ord9>ily /rung1 because ( ! great] sag betwe5 poles giv5 ! =m] & also probably because ( _! small] weight4 ,an illu/ration ( ?is sort may be se5 on ! old & new transmission l9es betwe5 ,niag>a ,falls & ,buffalo4 ,! two old copp] circuits consi/ ( six cables ( #cej1jjj circul> mils section ea* on "o l9e ( poles1 & are /rung ) only a mod]ate sag4 ,9 a /rong w9d ^! copp] conductors sw+ & vibrate 9 su* a way t _! poles1 p9s1 & cross-arms are ?r[n into a vibration t t5d to "w all atta*m5ts loose4 ,! new circuit consi/s ( ?ree #ejj1jjj circul> mil alum9um conductors on a sep>ate pole l9e /rung ) a l>ge sag betwe5 poles1 & ^! conductors take positions 9 planes at l>ge angles ) ! v]tical 9 a /rong w9d1 b cause little or no vibration ( _! supports4 ,"o reason = ! great] sag ( ! alum9um ov] t ( ! copp] conductors 9 ?is case is ! fact t ! poles c>ry+ ! =m] are #adj feet ap>t :ile ! di/ance betwe5 ! poles = ! latt] is only sev5ty feet1 on /raight sections ( ! l9e4 ,! necessity = great] sag 9 alum9um ?an 9 copp] conductors1 ev5 :]e ! span l5g?s are equal1 arises f ! great] coeffici5t ( expansion possess$ by ! =m] metal4 ,betwe5 #cb & #bab ,fahr5heit alum9um exp&s ab\t #j4jjbb1 & copp] #j4jjaf ( its l5g?1 s t ! *ange 9 l5g? is #dj p] c5t great] 9 ! =m] ?an 9 ! latt] metal4 ,! conductors 9 any case mu/ h en\gh sag betwe5 poles to provide = contraction 9 ! colde/ wea!r1 & x foll[s t ! necess>y sag ( alum9um wires w be great] ?an t ( copp] at ord9>y temp]ature4 ,9 pure air alum9um is ev5 m free f oxidation ?an copp]1 b :]e expos$ to ! fumes ( *emical works1 to *lor9e comp\nds1 or to fatty acids ! metal is rapidly attack$4 ,= ?is reason alum9um conductors %\ld h a wat]-pro( cov]+ :]e expos$ to any ( ^! *emicals4 ,! alum9um l9e betwe5 ,niag>a ,falls & ,buffalo is b>e = mo/ ( its l5g?1 b 9 ! vic9ity ( ! l>ge *emical works at ! =m] place ! wires are cov]$ ) a braid treat$ ) asphaltum4 ,alum9um alloy$ ) sodium1 its mo/ common impurity1 is quickly corrod$ 9 moi/ air1 & %\ld be c>efully avoid$4 ,all ( ! prop]ties ( alum9um "h m5tion$ relate to ! pure metal unless o!rwise /at$1 & its alloys %\ld n1 z a rule1 be consid]$ = transmission l9es4 ,z alum9um is electropositive to mo/ o!r metals ! sold]+ ( its jo9ts is q sure to result 9 electrolytic corrosion1 unless ! jo9ts are ?or\ghly protect$ f moi/ure1 a result t is h>d to atta9 ) b>e wires4 ,! regul> practice is to avoid ! use ( sold] & rely on me*anical jo9ts4 ,a good jo9t may be made by slipp+ ! r\gh5$ ends ( wires to be connect$ ?r\gh an alum9um tube ( oval section1 s t "o wire /icks out at ea* end1 !n twi/+ ! tube & wires & giv+ ea* ( ! latt] a turn ab\t ! o!r4 ,alum9um may be weld$ electrically & also by hamm]+ at a c]ta9 temp]ature1 b ^! processes are n conv5i5t = l9e con/ruction4 ,especial c>e is necess>y to avoid sc>r+ or cutt+ into alum9um wires1 z may be done :5 !y are ti$ to _! insulators4 ,alum9um tie wires %\ld be us$ exclusively4 ,to avoid ! great] dang] ( damage to solid wires & also to obta9 great] /r5g? & flexibility1 alum9um conductors are mo/ frequ5tly us$ 9 ! =m ( cables4 ,! sizes ( wires t g to make up ^! cables commonly range f ,no4 #f to #i ,b4 ,s4 gauge = widely diff]5t cable sections4 ,?us ! #ahc1gjh circul> mil alum9um cable betwe5 ,%aw9igan ,falls & ,montreal is made up ( sev5 ,no4 #f wires1 & ! #dga1jcd circul> mil cable betwe5 ,electra & ,mission ,san ,jos conta9s ?irty-sev5 ,no4 #i wires4 ,f ! ,f>m+ton ,riv] to ,h>t=d ea* #ccf1dbj circul> mils cable has exceptionally l>ge /r&s ( approximately ,no4 #c wire4 ,x appe>s f ! description ( a #dc-mile l9e 9 ,cali=nia 7vol4 xvii41 ,a4 ,i4 ,e4 ,e41 p4 #cde7 t a solid alum9um wire ( #bid mils diamet]1 or ,no4 #a ,b4 ,s4 gauge1 c be us$ )\t tr\ble f breaks4 ,?is wire 0 te/$ & its prop]ties report$ z foll[s3 ,diamet]1 #bic4i mils4 ,p\nds p] mile1 #dai4d4 ,resi/ance p] mil foot1 #ag4f ohms at #be ,c4 ,resi/ance p] mile at #be ,c41 #a4jjggc ohms4 ,conductivity z to copp] ( same size1 #ei4i p] c5t4 ,numb] ( twi/s 9 six in*es = fracture1 #ag4i4 ,t5sile /r5g? p] squ>e in*1 #cb1hih p\nds4 ,?is wire also /ood ! te/ ( wrapp+ six times ab\t its own diamet] & !n unwrapp+ & wrapp+ aga94 ,x 0 f\nd 9 te/s = t5sile /r5g? t ! wire 9 "q took a p]man5t set at v small loads1 b t at po9ts betwe5 #ad1jjj & #ag1jjj p\nds p] squ>e in* ! p]man5t set began to increase v rapidly4 ,f ?is x appe>s t alum9um wires & cables %\ld be giv5 en\gh sag betwe5 poles s t 9 ! colde/ wea!r ! /ra9s on !m %all n exce$ ab\t #ae1jjj p\nds p] squ>e in*4 ,?is r l[ safe work+ load is a disadvantage t alum9um %>es ) copp]4 ,f ! figures j giv5 x is evid5t t ! /ra9s on alum9um conductors dur+ _! erection %\ld n exce$ "o-half ( ! ultimate /r5g? 9 any case1 le/ _! sectional areas be r$uc$4 ,,alum9um ,,cables ,,9 ,,transmission ,,sy/ems4 ---------------------------------------- ------------------------- ,size ( ,numb],miles,circul>,/r&s ,/r&s4 ,locations4 ( ( ,mils ( p] ,b4 ,s4 ,g4 ,cables4,ea*4 ,ea*4 ,cable4 ,approx- imate4 ---------------------------------------- ------------------------- ,niag>a ,falls to ,buffalo #c #bj #ejj1jjj 44 44 ,%aw9igan ,falls to ,montreal #c #he #ahc1gjh #g #f ,electra to ,mission ,san ,jos #c #ajj #dga1jcd #cg #i ,colgate to ,oakl& #c #add #baa1jjj #g #e-f ,f>m+ton ,riv] to ,h>t=d #c #aa #ccf1dbj #g #c ,lewi/on1 ,me4 #c #c4e #add1fhh #g #h ,ludl[1 ,mass4 #f #d4e #ace1bdg #g #g ---------------------------------------- ------------------------- ,?is table ( transmission sy/ems us+ alum9um conductors is f> f exhau/ive4 ,alum9um is also be+ us$ to di/ribute en]gy to ! sub-/ations ( long electric railways1 z on ! ,aurora & ,*icago :i* connects cities ab\t =ty miles ap>t4 ,! l[] co/ ( alum9um conductors is also lead+ to _! adoption in/ead ( copp] 9 city di/ribution ( light & p[]4 ,?us at ,man*e/]1 ,n4 ,h41 ! local electric l9es include ab\t f\r miles ea* ( #ejj1jjj & #gej1jjj circul> mil alum9um cable ) wea!r-pro( insulation4 ,! l>g] ( ^! cables conta9s ?irty-sev5 /r&s ( ab\t ,no4 #g wire4 ,z may be se5 f ! =ego+ facts1 ! *oice ( copp] or alum9um = a transmission l9e %\ld turn ma9ly on ! co/ ( conductors ( ! requir$ l5g? & resi/ance 9 ea* metal4 ,s ne>ly balanc$ are ! me*anical & electrical prop]ties ( ! two metals t n m ?an a v small premium %\ld be paid = ! privilege ( us+ copp]4 ,z already po9t$ out1 ! co/s ( alum9um & copp] conductors ( giv5 l5g? & resi/ance are equal :5 ! price p] p\nd ( alum9um wire is twice t ( copp]4 ,dur+ mo/ ( ! "t = sev]al ye>s ! price ( alum9um has be5 well bel[ d\ble ! copp] figures1 & ! advantage has be5 ) alum9um conductors4 ,) ! two metals at ! same price p] p\nd alum9um w\ld co/ only "o-half z mu* z equival5t copp] conductors4 ,:5 ! price ( alum9um is fifty p] c5t great] p] p\nd ?an t ( copp]1 ! use ( ! =m] metal effects a sav+ ( tw5ty-five p] c5t4 ,= ! new ,niag>a & ,buffalo l9e1 complet$ e>ly 9 #aija1 alum9um 0 select$ because x effect$ a sav+ ( ab\t twelve p] c5t ov] ! co/ ( copp]4 ,all ( ! alum9um l9es "h m5tion$1 except ! %ort "o ne> ,h>t=d1 7 complet$ dur+ or s9ce #aijj4 ,mo/ ( ! facts "h /at$ z to ! l9e betwe5 ,niag>a ,falls & ,buffalo are drawn f vol4 xviii41 ,a4 ,i4 ,e4 ,e41 at pages #ebj & #eba4 ,! great] diamet] ( alum9um ov] equival5t copp] conductors has advantages 9 transmission ) alt]nat+ curr5t at v high voltages4 ,at high voltages1 say ( #dj1jjj or m1 ! con/ant sil5t loss ( en]gy f "o conductor to ano!r ( ! same circuit ?r\gh ! air t5ds to become l>ge & ev5 prohibitive 9 am\nt4 ,?is loss is great]1 o!r factors be+ con/ant1 ! small] ! diamet] ( ! conductors 9 ! l9e4 ,x foll[s t ?is loss is m s]i\s ! small] ! p[] to be transmitt$1 because ! small] ! diamet] ( ! l9e wires4 ,! sil5t passage ( en]gy f wire to wire increases directly ) ! l5g? ( l9e & ?us op]ates z a limit to long transmissions4 ,,*apt] ,,xvi4 ,,voltage ,,& ,,losses ,,on ,,transmission ,,l9es4 ,! voltage on a transmission l9e may be any?+ up to at lea/ #fj1jjj1 & ! weight ( conductors v>ies inv]sely ) ! squ>e ( ! figures select$1 ! p[]1 l5g? & loss be+ con/ant4 ,:atev] ! total l9e pressure1 ! weight ( conductors v>ies inv]sely ) ! p]c5tage ( loss !re94 ,! case ( maximum loss & m9imum weight ( conductors is t 9 :i* all ( ! transmitt$ en]gy is exp5d$ 9 heat+ ! l9e wires4 ,su* a case w\ld nev] occur 9 practice1 because ! object ( p[] transmission is to p]=m "s useful "w4 ,m9imum loss is !oretically z]o1 & ! correspond+ weight ( conductors is inf9ite1 b ^! conditions obvi\sly _c be atta9$ 9 practice4 ,betwe5 ^! extremes ( m9imum & ( inf9ite weights ( conductors comes e practical transmission ) a l9e loss great] ?an z]o & less ?an #ajj p] c5t4 ,to det]m9e ! weight & all[able co/ ( conductors1 ! co/ ( ! en]gy t w be annually lo/ 9 !m ent]s z "o ( ! factors4 ,at ?is po9t ! di/9ction betwe5 ! p]c5tage ( p[] lo/ at maximum load & ! p]c5tage ( total en]gy lo/ %\ld come into view4 ,l9e loss ord9>ily ref]s to ! p]c5tage ( total p[] consum$ 9 ! conductors at maximum load4 ,?is p]c5tage w\ld correspond ) t ( total en]gy lo/ if ! l9e curr5t & voltage 7 con/ant dur+ all p]iods ( op]ation1 b ?is is f> f ! case4 ,a sy/em ( transmission may op]ate ) ei!r con/ant volts or con/ant amp]es on ! l9e conductors1 b 9 a practical case con/ancy ( bo? ^! factors is seldom or nev] to be _h4 ,?is is because ! product ( ! l9e volts & amp]es repres5ts accurately 9 a cont9u\s-curr5t sy/em1 & approximately 9 an alt]nat+-curr5t sy/em1 ! am\nt ( p[] transmitt$4 ,9 an actual transmission sy/em1 ! load--t is1 ! dem& = p[]--is subject to m or less v>iation at diff]5t times ( ! day1 & ! l9e volts or amp]es1 or bo?1 mu/ v>y ) x4 ,if ! transmission sy/em is devot$ to ! op]ation ( "o or m factories ! requir$ p[] may n v>y m ?an tw5ty-five p] c5t dur+ ! h\rs ( daily use2 b if a sy/em ( g5]al electrical supply is to be op]at$1 ! maximum load w usually be some:]e betwe5 twice & f\r times z great z ! av]age load = ea* tw5ty-f\r h\rs4 ,su* fluctuat+ loads imply correspond+ *anges 9 ! volts or amp]es ( ! transmission l9e4 ,a numb] ( r long transmissions is c>ri$ out 9 ,europe ) cont9u\s1 con/ant curr5t1 & 9 su* sy/ems ! l9e voltage v>ies directly ) ! load4 ,z ! loss ( p[] 9 an electrical conductor dep5ds entirely on its ohms ( resi/ance1 :i* are con/ant at any giv5 temp]ature1 & on ! amp]es ( curr5t pass+ ?r\gh x1 ! l9e loss 9 a con/ant-curr5t sy/em does n *ange dur+ ! p]iod ( op]ation1 no matt] h[ great may be its *anges ( load4 ,= ?is reason ! p]c5tage ( p[] loss 9 ! l9e at maximum load is usually small] ?an ! p]c5tage ( en]gy loss = an entire day4 ,if1 = example1 ! con/ant-curr5t transmission l9e is design$ to conv]t into heat #e p] c5t ( ! maximum am\nt ( en]gy t w be deliv]$ to x p] second--t is1 to lose #e p] c5t ( its p[] at maximum load--!n1 :5 ! p[] :i* ! l9e receives drops to "o-half ( its maximum1 ! p]c5tage ( loss w rise to #aj1 because #j4je #j4e #j4a4 ,s aga91 :5 ! p[] s5t ?r\gh ! l9e falls to "o-qu>t] ( ! full am\nt1 ! l9e loss w rise to #j4je #j4be #j4b1 or #bj p] c5t4 ,f ^! facts x is cle> t a fair all-day effici5cy = a con/ant-curr5t transmission l9e c be obta9$ only 9 conjunction ) a high effici5cy at maximum load1 if widely v>y+ loads are to be op]at$4 ,x does n necess>ily foll[ f ^! facts z to losses 9 con/ant-curr5t l9es t su* losses %\ld always be small at maximum loads1 = if a l>ge loss may be p]mitt$ at full load a /ill great] p]c5tage ( loss at p>tial loads may n imply bad eng9e]+4 ,9 a l>ge p]c5tage ( electric wat]-p[] plants "s wat] goes ov] ! dam dur+ ^? h\rs ( ! day :5 loads are light1 ! /orage capacity above ! dam n be+ suffici5t to hold all ( ! surplus wat] dur+ mo/ seasons ( ! ye>4 ,if1 !re=e1 ! l9e loss 9 a con/ant-curr5t transmission1 :]e all ( ! daily fl[ ( wat] _c be us$1 is n great en\gh to r$uce ! maximum load t w\ld o!rwise be c>ri$1 !n ! fact t ! p]c5tage ( l9e loss at small loads is /ill l>g] is n v important4 ,obvi\sly1 x makes little diff]5ce :e!r wat] goes ov] a dam or ?r\gh :eels to make up = a loss 9 ! l9e4 ,9 a case :]e all ! wat] c be /or$ dur+ small loads & us$ dur+ heavy loads1 x is cle>ly desirable to keep ! loss 9 a con/ant-curr5t l9e d[n to a r l[ figure1 say n m ?an five p] c5t1 at maximum load4 ,mu* ! great] numb] ( electrical transmissions are c>ri$ out ) ne>ly con/ant l9e voltage1 mo/ly alt]nat+1 & ! l9e curr5t 9 su* cases v>ies directly ) ! p[] transmitt$1 except z to c]ta9 results ( inductance on alt]nat+ l9es4 ,z l9e resi/ance is con/ant1 save = slight v>iations due to temp]ature1 ! rate ( en]gy loss on a con/ant-pressure l9e v>ies ) ! squ>e ( ! numb] ( amp]es fl[+1 & ! p]c5tage ( loss ) any load v>ies directly z ! numb] ( amp]es4 ,^! relations betwe5 l9e losses & ! amp]es c>ri$ foll[ f ! law t ! p[]1 or rate ( "w1 is repres5t$ by ! product ( ! numb] ( volts by ! numb] ( amp]es1 & ! law t ! p[] actually lo/ 9 ! l9e is repres5t$ by ! product ( ! numb] ( ohms ( l9e resi/ance & ! squ>e ( ! numb] ( amp]es fl[+ 9 x4 ,9 ea* ( ^! cases ! p[] deliv]$ to ! l9e is1 ( c\rse1 measur$ 9 watts1 ea* ( :i* is #a_/gdf ( a horse-p[]4 ,apply+ ^! laws1 x appe>s t if ! loss ( a c]ta9 con/ant-pressure transmission l9e is #aj p] c5t ( ! p[] deliv]$ to x at full load1 !n1 :5 ! p[]1 & consequ5tly ! amp]es1 on ! l9e is r$uc$ "o-half1 ! watts lo/ 9 ! l9e z heat w be 7#a_/b7 #a_/d ( ! watts lo/ at full load1 because ! numb] ( amp]es fl[+ has be5 divid$ by #b4 ,b ! am\nt ( p[] deliv]$ to ! l9e at full load hav+ be5 r$uc$ by #ej p] c5t1 :ile ! p[] lo/ on ! l9e dropp$ to "o-f\r? ( #aj p] c5t1 or to #b4e p] c5t ( ! full l9e load1 x foll[s t ! p[] lo/ on ! l9e at half-load is repres5t$ by #j4jbe #j4e #j4je1 or #e p] c5t ( ! p[] !n deliv]$ to x4 ,?is rise 9 ! effici5cy ( a con/ant-pressure transmission l9e z ! p[] deliv]$ to x decreases1 toge!r ) ! fact t maximum loads on su* l9es cont9ue dur+ h>dly m ?an "o to two h\rs daily1 t5ds to raise ! all[able p]c5tage ( l9e loss at maximum loads4 ,?is is s because a loss ( fifte5 p] c5t at maximum load may easily drop to an av]age loss ( some:]e betwe5 five & t5 p] c5t = ! entire am\nt ( en]gy deliv]$ to a l9e dur+ ea* day "u ord9>y conditions 9 electrical supply4 ,9 ! practical design ( transmission l9es1 !re=e1 ! sizes ( conductors are influ5c$ by ! relation ( ! l>ge/ load to be op]at$ to ! greate/ am\nt ( p[] available = its op]ation1 & by que/ions ( regulation1 z well z by consid]ations ( all-day effici5cy4 ,if ! maximum load t mu/ be c>ri$ by a transmission sy/em dur+ a s+le h\r p] day requires ne>ly z mu* p[] z c be deliv]$ to ! l9e conductors1 ei!r because ( lack ( wat] /orage or ( wat] itself1 ev5 if x is /or$1 x may be desirable to design ^! conductors = a small loss at maximum load1 r ?an to in/all a /eam plant4 ,s aga91 z ! fluctuation 9 voltage at ! deliv]y end ( a transmission l9e betwe5 no load & full load w am\nt to ! entire drop ( volts 9 ! l9e at full load1 if ! pressure at ! g5]at+ end is con/ant1 ! requirem5ts ( pressure regulation on di/ribution circuits limit ! drop ( pressure 9 ! transmission conductors4 ,= good light+ s]vice ) inc&esc5t lamps at ab\t #aaj volts1 ! usual pressure1 x is necess>y t v>iations be held )9 "o volt ei!r way ( ! pressure ( ! lamps--t is1 betwe5 #aji & #aaa volts4 ,e long-transmission sy/em = g5]al electrical supply necess>ily includes "o or m sub-/ations :]e ! di/ribution l9es jo9 ! transmission circuits1 & :]e ! voltage = light+ s]vice is regulat$4 ,z ! limits ( voltage v>iations on light+ circuits are s n>r[1 x is necess>y to keep ! *anges ( pressure on ! transmission l9es !mselves )9 mod]ate limits1 or su* z c be comp5sat$ = at sub-/ations4 ,?is is p>ticul>ly true 9 cases :]e en]gy transmitt$ ov] a s+le circuit is di/ribut$ = bo? inc&esc5t lamps & l>ge electric motors1 because ! />t+ & op]ation ( su* motors causes l>ge fluctuations ( amp]es & t]m9al voltage on ! transmission circuits4 ,to hold su* fluctuations )9 limits :i* a sub-/ation c readily comp5sate =1 x is necess>y t ! loss 9 ! transmission l9e be mod]ate1 say (t5 )9 t5 p] c5t ( ! total voltage deliv]$ to x at maximum load4 ,capacity & co/ ( equipm5t at g5]at+ /ations g up ) ! p]c5tage ( l9e loss1 & ?us s]ve to limit its economical am\nt4 ,= e horse-p[] deliv]$ to a transmission l9e at a wat]-p[] /ation !re mu/ be some:at m ?an "o horse-p[] ( capacity 9 wat]-:eels1 at lea/ "o horse-p[] 9 g5]ators1 & frequ5tly a fur!r capacity ( "o horse-p[] 9 /ep-up trans=m]s4 ,e additional horse-p[] lo/ 9 ! l9e at maximum load1 if ! g5]at+ plant is to be work$ up to its full capacity1 implies an addition ( some:at m ?an "o horse-p[] capacity 9 wat]-:eels1 "o horse-p[] 9 g5]ators1 & "o horse-p[] 9 trans=m]s4 ,s9ce ! co/ ( a g5]at+ /ation is ?us increas$ z ! maximum l9e loss is rais$1 a po9t may be rea*$ :]e any fur!r sav+ 9 ! co/ ( ! l9e is m ?an (fset by ! correspond+ addition to ! co/ ( ! /ation & ( its op]ation4 ,j :]e ?is po9t1 z indicat$ by a p]c5tage ( l9e loss1 is to be f\nd dep5ds on ! factors ( ea* case1 important among :i* is ! l5g? ( ! transmission l9e4 ,mu* ef=t has be5 made to fix "s exact relation = maximum economy betwe5 ! fir/ co/ ( conductors = a transmission l9e & ! am\nt ( en]gy annually lo/ z heat !re94 ,! be/-kn[n /atem5t apply+ to ?is case is t ( ,"l ,kelv91 made 9 a pap] read be=e ! ,briti% ,association 9 #ahha4 ,accord+ to ! rule !re laid d[n1 ! mo/ economical size = ! conductors ( a transmission l9e is t = :i* ! annual int]e/ on fir/ co/ equals ! co/ ( ! en]gy annually wa/$ 9 !m4 ,if transmission sy/ems 7 design$ = ! sole purpose ( wa/+ en]gy 9 _! l9e conductors ?is rule w\ld exactly apply1 = x simply %[s h[ ! co/ ( en]gy wa/$1 plus ! int]e/ on ! co/ ( ! conductor 9 :i* x is wa/$1 may be br\ght to a m9imum4 ,z a matt] ( fact1 transmission sy/ems are prim>ily int5d$ to deliv] en]gy r ?an to wa/e x2 b ( ! proportions ( ! entire en]gy to be deliv]$ & wa/$ 7:i* is exactly :at we want to "k71 ! rule ( ,kelv9 takes no acc\nt4 ,accord+ to 8 rule1 ! *eap] ! co/ ( p[] :]e x is develop$1 ! less %\ld be paid = conductors to br+ x to m>ket4 ,! obvi\s tru? is t ! less ! co/ ( p[] developm5t at a p>ticul> po9t1 ! m may be inve/$ 9 a l9e to br+ x to m>ket4 ,if p[] co/ no?+ :atev] at its s\rce x w\ld n be wor? :ile to build any transmission l9e at all if ?is rule is correct4 ,a modification ( ,"l ,kelv9's rule has be5 propos$ by :i* x is said t ! int]e/ on ! co/ ( ! conductors & ! annual value ( ! en]gy lo/ 9 !m %\ld be equal1 value "h mean+ :at ! en]gy c be sold =4 ,?is rule w\ld make an inve/m5t 9 l9e conductors too l>ge4 ,! entire co/ ( production & transmission = ! deliv]$ en]gy %\ld n be great] ?an ! co/ ( a l am\nt ( en]gy develop$ at ! po9t :]e ! deliv]y is made4 ,9 ?is entire co/ ( production & transmission1 int]e/ on ! inve/m5t 9 l9e conductors is only "o item4 ,x is p]haps impossible to /ate any exact rule = ! mo/ economical relation betwe5 ! co/ ( conductors & ! loss ( en]gy !re9 t w apply to e transmission4 ,a maximum limit to ! weight ( conductors may1 h[ev]1 be set = mo/ cases4 ,?is limit %\ld n all[ ! annual int]e/ & depreciation *>ges on ! inve/m5t 9 l9e conductors1 plus all o!r co/s ( developm5t & transmission1 to raise ! total co/ ( ! transmitt$ en]gy above ! co/ ( developm5t = an equal am\nt ( en]gy at ! po9t :]e ! transmitt$ en]gy is deliv]$4 ,:ile ! maximum inve/m5t 9 transmission conductors may be prop]ly limit$ 9 ! way j /at$1 x by no means foll[s t ?is maximum limit %\ld be rea*$ 9 e case4 ,9 ! v>y+ requirem5ts ( actual cases1 ! problem may be to deliv] a fix$ am\nt ( p[] at ! lea/ possible co/1 or to deliv] ! l>ge/ possible am\nt ( p[] at a co/ p] unit "u t ( developm5t at ! po9t ( use4 ,frequ5tly a transmission sy/em has a possible capacity 9 excess ( pres5t requirem5ts1 & a l9e t w\ld n be too heavy = future bus9ess might put an unreasonable burd5 ( int]e/ *>ges on pres5t e>n+s4 ,! =ego+ consid]ations apply to ! design ( conductors = a transmission l9e aft] ! voltage at :i* x is to op]ate has be5 decid$ on4 ,q a diff]5t set ( facts %\ld influ5ce ! selection ( ?is voltage4 ,a transmission t w\ld be entirely impracticable ) any p]c5tage ( l9e loss t might be select$1 if c>ri$ out at "s "o voltage1 might repres5t a pay+ bus9ess at "s high] voltage & any "o ( sev]al sizes ( l9e conductors4 ,! p[] t c\ld be deliv]$ by a l9e ( practicable co/1 op]at$ at "o voltage1 might be too small = ! purpose 9 h&1 :ile ! available p[] at a high] voltage might be ample4 ,if any giv5 p[] is to be transmitt$ ) a giv5 p]c5tage ( maximum loss 9 l9e conductors1 ! weight ( ^! conductors w increase z ! squ>e ( _! l5g?1 & decrease z ! squ>e ( ! full voltage ( op]ation 9 e case4 ,?us1 if ! l5g? ( ?is transmission is d\bl$1 ! weight ( ! conductors mu/ be multipli$ by f\r1 ! voltage rema9+ ! same2 b if ! voltage is d\bl$ & ! l9e l5g? rema9s un*ang$1 ! weight ( conductors mu/ be divid$ by f\r4 ,) ! l5g? ( l9e & ! voltage ( transmission ei!r l[]$ or rais$ toge!r1 ! weight ( ! conductors rema9s fix$1 = con/ant p[] & loss4 ,an illu/ration ( ?is la/ rule may be drawn f ! case ( l9es design$ to transmit any giv5 p[] a di/ance ( t5 miles at #aj1jjj volts1 & a di/ance ( fifty miles at #ej1jjj volts1 9 :i* ! total weight ( conductors w\ld be ! same = ea* l9e if ! p]c5tage ( loss 0 con/ant4 ,?is /atem5t ( ! rule z to proportionate increase ( voltage & di/ance pres5ts ! advantages ( high voltages 9 _! mo/ favorable light4 ,?\gh a uni=m ratio betwe5 ! voltage ( op]ation & ! l5g? ( l9e all[s a con/ant weight ( conductors to be employ$ = ! transmission ( a giv5 p[] ) un*ang+ effici5cy ( conductors1 yet o!r consid]ations soon limit ! advantage ?us obta9$4 ,important among ^! consid]ations may be m5tion$ ! me*anical /r5g? ( l9e conductors1 difficulties ( l9e insulation1 losses betwe5 conductors ?r\gh ! air1 limits ( g5]ator voltages1 & ! co/ ( trans=m]s4 ,if ! t5-mile transmission at #aj1jjj volts1 above m5tion$1 requires a circuit ( two ,no4 #a_/j copp] wires1 ! total weight ( ^! wires w be repres5t$ by 7#e1ejj #aj #b #cbj7 #a1jjj #ce1bjj p\nds1 all[+ #e1ejj feet ( wire p] mile ( s+le conductor to provide some?+ = sag betwe5 poles1 & #cbj p\nds be+ ! weight ( b>e ,no4 #a_/j copp] wire p] #a1jjj feet4 ,:5 ! l5g? ( l9e is rais$ to #ej miles1 ! two-wire circuit w conta9 #e1ejj #ej #b #eej1jjj feet ( s+le conductor1 & s9ce ! voltage is rais$ to #ej1jjj at ! same "t1 ! total weight ( conductors w be #ce1bjj p\nds z be=e4 ,! weight ( s+le conductor p] #a1jjj feet is !re=e only #fd p\nds 9 ! #ej-mile l9e4 ,a ,no4 #g copp] wire1 ,b4 ,s4 gauge1 has a weight ( #fc p\nds p] #a1jjj feet1 & is ! ne>e/ regul> size to t requir$ = ! #ej-mile l9e z j f\nd4 ,x w\ld be poor policy to /r+ a wire ( ?is size = a transmission l9e1 because x is s weak me*anically t breaks w\ld probably be frequ5t 9 /ormy wea!r4 ,! elem5t ( unreliability introduc$ by ! use ( ?is small wire on a #ej-mile l9e w\ld co/ f> m 9 ! end ?an a l>g] conductor4 ,z a rule1 ,no4 #d ,b4 ,s4 gauge wire is ! smalle/ t %\ld be us$ on a long transmission l9e 9 ord] to give fair me*anical /r5g?1 & ?is size has j twice ! weight ( a ,no4 #g wire ( equal l5g?4 ,"h1 !n1 is "o ( ! practical limits to ! advantages t may be ga9$ by increas+ ! voltage ) ! l5g? ( l9e4 ,z l9e voltage goes up1 ! /ra9 on l9e insulation increases rapidly1 & ! insulators = a circuit op]at$ at #ej1jjj volts mu/ be l>g] & ( a mu* m exp5sive "* ?an ^? = a #aj1jjj-volt circuit4 ,9 ?is way a "p ( ! sav+ 9 conductors effect$ by ! use ( v high voltages on long l9es is (fset by ! increas$ co/ ( insulation4 ,ano!r disadvantage t att5ds ! op]ation ( transmission l9es at v high voltages is ! cont9u\s loss ( en]gy by ! sil5t passage ( curr5t ?r\gh ! air betwe5 wires ( a circuit4 ,?is loss increases at a rapid rate aft] a pressure betwe5 #dj1jjj & #ej1jjj volts is rea*$ ) ord9>y di/ances betwe5 ! wires ( ea* circuit4 ,to keep losses ( ?is sort )9 mod]ate limits1 & also to less5 ! probability ( arcs on a circuit at v high voltage1 ! di/ance ( eighte5 in*es or two feet betwe5 conductors t c>ry curr5t at #aj1jjj volts %\ld be increas$ to six feet or m on circuits t op]ate at #ej1jjj volts4 ,su* an increase 9 ! di/ance betwe5 conductors makes ! co/ ( poles & cross-arms great]1 ei!r by requir+ !m to be l>g] ?an w\ld o!rwise be necess>y or by limit+ ! numb] ( wires to two or ?ree p] pole & ?us increas+ ! numb] ( pole l9es4 ,^! add$ exp5ses =m ano!r "p ( ! p5alty t mu/ be paid = ! use ( v high voltages & ! att5dant sav+ 9 ! co/ ( conductors4 ,app>atus gr[s m exp5sive z ! voltage at :i* x is to op]ate increases1 because ( ! co/ ( insulat+ mat]ials & ! room :i* !y take up1 !reby add+ to ! size & weight ( ! iron p>ts4 ,g5]ators = alt]nat+ curr5t c be _h t develop z mu* z #ac1ejj volts1 b su* g5]ators co/ m ?an o!rs ( equal p[] t op]ate at betwe5 #b1jjj & #b1ejj volts4 ,^! latt] voltages are z high z x is usually ?\ght desirable to op]ate di/ribution circuits & s]vice trans=m]s 9 cities & t[ns1 s t if m ?an #b1ejj volts are employ$ on ! transmission l9e1 /ep-d[n trans=m]s are requir$ at a sub-/ation4 ,= a transmission ( m ?an t5 miles ! sav+ 9 l9e conductors by op]ation at #aj1jjj to #ab1jjj volts w usually m ?an (fset ! additional co/ ( g5]ators design$ = ?is pressure & ( /ep-d[n trans=m]s4 ,if ! voltage ( transmission is to exce$ t ( di/ribution1 x w g5]ally be f\nd desirable to c>ry ! =m] voltage up to #aj1jjj or #ab1jjj1 at lea/4 ,z ! co/ ( g5]ators design$ = ! voltage la/ nam$ is less ?an t ( l[] voltage g5]ators plus trans=m]s1 /ep-up trans=m]s %\ld usually be omitt$ 9 sy/ems :]e ^! pressures are n exce$$4 ,= alt]nat+ pressures above #ac1jjj to #ae1jjj volts1 /ep-up trans=m]s mu/ g5]ally be employ$4 ,9 ord] t ! sav+ 9 ! weight ( l9e conductors may m ?an (fset ! additional co/ ( trans=m]s :5 ! voltage ( transmission is c>ri$ above #ae1jjj1 ?is voltage %\ld be pu%$ on up to z mu* z #be1jjj 9 mo/ cases4 ,p[] transmission ) cont9u\s curr5t has ! advantage t ! co/ ( g5]ators rema9s ne>ly ! same :atev] ! l9e voltage1 & t no trans=m]s are requir$4 ,su* transmissions are common 9 ,europe1 b h h>dly a foot+ z yet 9 ! ,unit$ ,/ates4 ,! reason = ! uni=m co/ ( cont9u\s-curr5t g5]ators is f\nd 9 ! fact t !y are connect$ 9 s]ies to give ! desir$ l9e voltage1 & ! voltage ( ea* ma*9e is kept "u #c1jjj or #d1jjj4 ,z a p>tial (fset to ! l[ co/ ( ! cont9u\s-curr5t g5]ators & to ! abs5ce ( trans=m]s1 !re is ! necessity = motor-g5]ators 9 a sub-/ation :5 curr5t = light+ z well z p[] is to be di/ribut$4 ,9 spite ( ! v>i\s additions to ! co/ ( transmission sy/ems made necess>y by ! adoption ( v high voltages1 ^! additions are mu* m ?an (fset by ! sav+ 9 ! co/ ( conductors on l9es #cj1 #ej1 or #ajj miles 9 l5g?4 ,9 fact1 x is only by means ( voltages rang+ f #be1jjj to #ej1jjj t ! greate/ ( ^! di/ances1 & o!rs up to m ?an #adj miles1 h be5 successfully cov]$ by transmission l9es4 ,above #fj1jjj volts !re has be5 b slight practical exp]i5ce 9 ! op]ation ( transmission l9es4 ,calculations to det]m9e ! sizes ( conductors = electric transmission l9es are all bas$ on ! fundam5tal law discov]$ by ,ohm1 :i* is t ! electric curr5t fl[+ 9 a circuit at any in/ant equals ! electric pressure t causes ! curr5t divid$ by ! electric resi/ance ( ! circuit itself1 or curr5t pressure resi/ance4 ,sub/itut+ 9 ?is =mula ! units t h be5 select$ because ( _! conv5i5t sizes = practical use1 x becomes1 amp]es volts ohms1 9 :i* ! ohm is simply ! electrical resi/ance1 tak5 z unity1 ( a c]ta9 /&>d copp] b> ) fix$ dim5sions4 ,! amp]e is ! unit fl[ ( curr5t t is ma9ta9$ ) ! unit pressure ( "o volt betwe5 ! t]m9als ( a "o-ohm conductor4 ,:5 ?is =mula is appli$ to ! computation ( transmission l9es ! volts repres5t ! electrical pressure t is requir$ to =ce ! desir$ amp]es ( curr5t ?r\gh ! ohms ( resi/ance 9 any p>ticul> l9e1 & ^! volts h no necess>y or fix$ relation to ! total voltage at :i* ! l9e may op]ate4 ,?us1 if ! total voltage ( a transmission sy/em is #aj1jjj1 x may be desirable to use #ejj1 #a1jjj1 or ev5 #b1jjj volts to =ce curr5t ?r\gh ! l9e1 s t "o ( ^! numb]s w repres5t ! actual drop or loss ( volts 9 ! l9e conductors :5 ! numb] ( amp]es t repres5t full load is fl[+4 ,z x is a law ( e electric circuit t ! rate ( trans=mation ( electric en]gy to heat or "w 9 ea* ( its sev]al p>ts is directly proportional to ! drop ( voltage !re91 x foll[s t a drop ( #ejj or #a1jjj or #b1jjj volts 9 ! conductors ( a #aj1jjj-volt transmission l9e at full load w\ld correspond to a p[] loss ( five to t5 or tw5ty p] c5t respectively4 ,any o!r "p ( #aj1jjj volts might be select$ 9 ?is case z ! pressure to be lo/ 9 ! l9e4 ,evid5tly no =mula c give ! numb] ( volts t %\ld be lo/ 9 l9e conductors at full load = a giv5 p[] transmission1 b ?is numb] mu/ be decid$ on by consid]ation ( ! items ( l9e effici5cy1 regulation1 & ! ratio ( ! available p[] to ! requir$ load4 ,hav+ decid$ on ! maximum loss ( volts 9 ! l9e conductors1 & kn[+ ! full voltage ( op]ation1 ! p[] & consequ5tly ! numb] ( amp]es deliv]$ to ! l9e at maximum load1 ! resi/ance ( ! conductors may !n be calculat$ by ! =mula1 amp]es volts ohms4 ,?us1 if ! proposition is to deliv] #b1jjj1jjj watts or #b1jjj kil[atts to a two-wire transmission l9e ) a voltage ( #bj1jjj1 ! amp]es 9 ea* wire mu/ be repres5t$ by #b1jjj1jjj #bj1jjj #ajj4 ,) a drop ( t5 p] c5t or #b1jjj volts 9 ! two l9e conductors1 _! comb9$ resi/ance mu/ be f\nd f #ajj #b1jjj ohms1 & ! ohms are !re=e tw5ty4 ,if ! comb9$ l5g? ( ! two conductors is #bjj1jjj feet1 correspond+ to a transmission l9e ( a little "u tw5ty miles1 ! resi/ance ( ^! conductors mu/ be #bj #bjj #j4a ohm p] #a1jjj feet4 ,f a wire table x may be se5 t a ,no4 #a_/j wire ( copp]1 ,b4 ,s4 gauge1 ) a diamet] ( #j4cbdi in*1 has a resi/ance ( #j4ajja ohm p] #a1jjj feet at ! temp]ature ( #ij ,fahr5heit1 a little less at l[] temp]atures1 & is ?us ! requir$ size4 ,obvi\sly1 ! resi/ance ( tw5ty ohms is entirely indep5d5t ( ! l5g? ( ! l9e1 all ! o!r factors be+ con/ant1 & wires ( v>i\s sizes w be requir$ = o!r di/ances ( transmission4 ,x is (t5 conv5i5t to f9d ! area ( cross section = ! desir$ transmission conductor in/ead ( f9d+ its resi/ance4 ,?is c be done by sub/itut+ 9 ! =mula1 amp]es volts ohms1 ! expression = ! numb] ( ohms 9 any conductor1 & !n solv+ z be=e4 ,electrical resi/ance 9 e conductor v>ies directly ) its l5g?1 inv]sely ) its area ( cross section1 & also has a con/ant factor t dep5ds on ! mat]ial ( :i* ! conductor is compos$4 ,?is con/ant factor is always ! same = any giv5 mat]ial1 z pure iron1 copp]1 or alum9um1 & is usually tak5 z ! resi/ance 9 ohms ( a r\nd wire "o foot long & #j4jja in* 9 diamet]1 ( ! mat]ial to be us$ = conductors4 ,su* a wire is said to h an area 9 cross section ( "o circul> mil1 because ! squ>e ( its diamet] tak5 z unity is /ill unity1 t is1 #a #a #a4 ,9 l mann]1 = ! conv5i5t designation ( wires by _! areas ( cross-section1 ea* r\nd wire ( any size is said to h an area 9 circul> mils equal to ! squ>e ( its diamet] measur$ 9 units ( #j4jja in* ea*4 ,?us1 a r\nd wire ( #j4a in* diamet] has an area ( #ajj #ajj #aj1jjj circul> mils1 & a r\nd wire "o in* 9 diamet] has an area ( #a1jjj #ajjj #a1jjj1jjj circul> mils4 ,! circul> mils ( a wire d n express its area ( cross section 9 t]ms ( squ>e in*es1 b ?is is n necess>y s9ce ! resi/ance ( a wire ( "o circul> mil is tak5 z unity4 ,obvi\sly1 ! areas ( all r\nd wires are to ea* o!r z are _! circul> mils4 ,f ! =ego+ x may be se5 t ! resi/ance ( any r\nd conductor is repres5t$ by ! =mula1 ohms l s circul> mils1 9 :i* l repres5ts ! l5g? ( ! conductor 9 feet1 s is ! resi/ance 9 ohms ( a wire ( ! same mat]ial z ! conductor b ) an area ( "o circul> mil & a l5g? ( "o foot1 & ! circul> mils are ^? ( ! requir$ conductor4 ,sub/itut+ ! quantity1 l s circul> mils1 = ohms 9 ! =mula1 amp]es volts ohms1 ! equation1 amp]es volts 7l s circul> mils71 is obta9$1 & ?is r$uces to circul> mils amp]es l s volts4 ,= any propos$ transmission all ( ! quantities 9 ?is =mula are kn[n1 except ! desir$ circul> mils ( ! l9e conductors4 ,! con/ant quantity s is ab\t #aj4h = copp]1 b is conv5i5tly us$ z elev5 9 calculation1 & ?is all[s a trifle = ! effects ( impurities t may exi/ 9 ! l9e wire4 ,! case above m5tion$1 :]e #b1jjj kil[atts 7 to be deliv]$ to a transmission l9e at #bj1jjj volts1 & a loss ( #b1jjj volts at full load 0 all[$ 9 ! l9e conductors1 may n[ be solv$ by ! =mula = circul> mils4 ,tak+ ! resi/ance ( a r\nd copp] wire #j4jja in* 9 diamet] & "o foot long z elev5 ohms1 & sub/itut+ ! #ajj amp]es1 #b1jjj volts1 & #bjj1jjj feet ( ! pres5t case 9 ! =mula1 gives circul> mils 7#ajj #bjj1jjj #aa7 #b1jjj #aaj1jjj4 ,! squ>e root ( ?is #aaj1jjj w give ! diamet] ( a copp] wire t w exactly meet ! conditions ( ! case1 or ! m practical c\rse ( consult+ a table ( /&>d sizes ( wire w %[ t a ,no4 #a-j ,b4 ,s4 gauge1 ) a diamet] ( #j4cbdi in*1 has a cross section ( #aje1ejj circul> mils1 or ab\t five p] c5t less ?an ! calculat$ numb]1 & is ! size ne>e/ to t want$4 ,z ?is ,no4 #a-j wire w give a l9e loss at full load ( ab\t #aj4e p] c5t1 or only "o-half ( "o p] c5t m ?an ! loss at fir/ select$1 x %\ld be adopt$ = ! l9e 9 ?is case4 ,! =mula j made use ( is p]fectly g5]al 9 its application1 & may be appli$ to ! calculation ( l9es ( alum9um or iron or any o!r metal j z well z to l9es ( copp]4 ,9 ord] to use ! =mula = any desir$ metal1 x is necess>y t ! resi/ance 9 ohms ( a r\nd wire ( t metal "o foot long & #j4jja in* 9 diamet] be kn[n & sub/itut$ = s 9 ! =mula4 ,?is resi/ance ( a wire "o foot long & #j4jja in* 9 diamet] is call$ ! specific resi/ance ( ! sub/ance ( :i* ! wire is compos$4 ,= pure alum9um ?is specific resi/ance is ab\t #ag4g1 = s(t iron ab\t sixty1 & = h>d /eel ab\t eighty ohms4 ,! use ( ^! values = s 9 ! =mula w !re=e give ! areas 9 circul> mils = wires ( ^! ?ree sub/ances1 respectively1 = any propos$ transmission l9e4 ,9 ! same way ! specific resi/ance ( any o!r metal or alloy1 :5 kn[n1 may be appli$ 9 ! =mula4 ,! =ego+ calculations apply accurately to all two-wire circuits t c>ry cont9u\s curr5ts1 :e!r ^! circuits op]ate ) con/ant curr5t1 con/ant pressure1 or ) pressure & curr5t bo? v>iable4 ,:]e circuits are to c>ry alt]nat+ curr5ts1 c]ta9 o!r factors may require consid]ation4 ,almo/ all transmissions ) alt]nat+ curr5ts are c>ri$ out ) ?ree-phase ?ree-wire1 or two-phase f\r-wire1 or s+le-phase two-wire circuits4 ,( ! entire numb] ( su* transmissions1 ^? ) ! ?ree-phase ?ree-wire circuits are 9 ! majority1 next 9 po9t ( numb] come ! two-phase transmissions1 & la/ly a few transmissions are c>ri$ out ) s+le-phase curr5ts4 ,! voltage ( a cont9u\s-curr5t circuit1 by :i* ! p[] ( ! transmission is comput$ & on :i* ! p]c5tage ( l9e loss is bas$1 is ! maximum voltage op]at+ !re2 b ?is is n true = circuits c>ry+ alt]nat+ curr5ts4 ,bo? ! volts & amp]es 9 an alt]nat+ circuit are con/antly v>y+ betwe5 maximum values 9 opposite directions along ! wires4 ,x foll[s f ?is fact t bo? ! volts & amp]es drop to z]o z (t5 z !y rise to a maximum4 ,x is fully demon/rat$ 9 books on ! !ory ( alt]nat+ curr5ts1 t ) c]ta9 ideal con/ructions 9 alt]nat+ g5]ators1 & c]ta9 conditions 9 ! circuits to :i* !y are connect$1 ! equival5t or1 z !y are call$1 ! virtual values ( ! con/antly *ang+ volts & amp]es 9 ^! circuits are #j4gjg ( _! respective maximum values4 ,or1 to /ate ! rev]se ( ?is proposition1 ! maximum volts & amp]es respectively 9 ^! circuits rise to #a4dad times _! equival5t or virtual values4 ,^! relations betwe5 maximum & virtual volts & amp]es are subject to "s v>iations ) actual circuits & g5]ators1 b ! virtual values ( ^! factors1 z measur$ by suitable volt- & amp]emet]s1 are important 9 ! design ( transmission circuits1 r ?an _! maximum values4 ,:5 ! volts or amp]es ( an alt]nat+ circuit are m5tion$1 ! virtual values ( ^! factors are usually meant unless "s o!r value is specifi$4 ,?us1 z commonly /at$1 ! voltage ( a s+le-phase circuit is ! numb] ( virtual volts betwe5 its two conductors1 ! voltage ( a two-phase circuit is ! numb] ( virtual volts betwe5 ea* pair ( its f\r conductors1 & ! voltage ( a ?ree-phase circuit is ! numb] ( virtual volts betwe5 ei!r two ( its ?ree conductors4 ,sev]al factors n pres5t ) cont9u\s curr5ts t5d to affect ! losses 9 conductors :]e alt]nat+ curr5ts are fl[+1 & ! importance ( su* effects w be not$ lat]4 ,9 spite ( su* effects1 ! =mula above discuss$ %\ld be appli$ to ! calculation ( transmission l9es = alt]nat+ curr5ts1 & !n ! prop] corrections ( ! results1 if any are necess>y1 %\ld be made4 ,) ?is proviso z to corrections1 ! virtual volts & amp]es ( circuits c>ry+ alt]nat+ curr5ts may be us$ 9 ! =mula 9 ! same way z ! actual volts & amp]es ( cont9u\s curr5t circuits4 ,?us1 rev]t+ to ! above example1 :]e #b1jjj kil[atts 0 to be deliv]$ at #bj1jjj volts to a transmission l9e 9 :i* ! loss 0 to be #b1jjj volts1 ! kil[atts %\ld be tak5 z ! actual rate ( "w repres5t$ by ! alt]nat+ curr5t1 & ! volts nam$ z ! virtual volts on ! l9e4 ,! virtual amp]es w n[ be #ajj1 z 7 ! actual amp]es ( cont9u\s curr5t1 & ! size ( l9e conductor = a s+le-phase alt]nat+ transmission w !re=e be #a-j1 ! same z = ! cont9u\s-curr5t l9e4 ,if ! transmission is to be c>ri$ out on ! two-phase f\r-wire sy/em1 ! virtual amp]es 9 ea* ( ^! wires w be fifty in/ead ( #ajj1 z ! p[] w be divid$ equally betwe5 ! two pairs ( conductors1 & ea* ( ^! f\r wires %\ld h a cross-section 9 circul> mils j "o-half z great z t ( ! ,no4 #a-j wire4 ,! requir$ wire w ?us be a ,no4 #c ,b4 ,s4 gauge1 ( #eb1fcj circul> mils1 ?is be+ ! ne>e/ /&>d size4 ,9 weight ! two ,no4 #a-j wires & ! f\r ,no4 #c wires are almo/ equal1 & !y %\ld be exactly equal to give ! same loss 9 ! s+le-phase & ! two-phase l9es4 ,= a ?ree-phase circuit to make ! transmission above consid]$1 ea* ( ! ?ree conductors %\ld h an area j "o-half z great z t ( ea* ( ! two conductors = a s+le phase circuit1 ! loss rema9+ z be=e1 & ! ne>e/ /&>d size ( wire is aga9 ,no4 #c1 z x 0 = ! two-phase l9e4 ,?is is n a self-evid5t proposition1 b ! pro( c be f\nd 9 books devot$ to ! !ory ( ! subject4 ,f ! =ego+ x is evid5t t :ile ! s+le-phase & two-phase l9es require equal weights ( conductors1 all o!r factors be+ ! same1 ! weight ( conductors 9 ! ?ree-phase l9e is only sev5ty-five p] c5t ( t 9 ei!r ( ! o!r two4 ,neglect+ ! special factors t t5d to raise ! size & weight ( alt]nat+-curr5t circuits1 ! s+le-phase & two-phase l9es require ! same weight ( conductors z does a cont9u\s-curr5t transmission ( equal p[]1 voltage1 & l9e loss4 ,x %\ld be not$ t 9 ea* ( ^! cases ! factor l 9 ! =mula = circul> mils d5otes ! entire l5g? ( ! pair ( conductors = a cont9u\s-curr5t l9e1 or d\ble ! di/ance ( ! transmission ) ei!r ( ! alt]nat+-curr5t l9es4 ,hav+ f\nd ! circul> mils ( any desir$ conductor1 its weight p] #a1jjj feet c be f\nd readily 9 a wire table4 ,9 "s cases x is desirable to calculate ! weight ( ! conductors = a transmission l9e )\t f9d+ ! circul> mils ( ea*1 & ?is c be done by a modification ( ! above =mula4 ,a copp] wire ( #a1jjj1jjj circul> mils weighs ne>ly #c4jc p\nds p] foot ( its l5g?1 & ! weight ( any copp] wire may !re=e be f\nd f ! =mula1 p\nds 7circul> mils #c4jc l7 #a1jjj1jjj1 9 :i* p\nds indicates ! total weight ( ! conductor1 l1 its total l5g?1 & ! circul> mils are ^? ( its cross-section4 ,?is =mula r$uces to ! =m1 circul> mils 7#a1jjj1jjj p\nds7 7#c4jc l7 & if ?is value = circul> mils is sub/itut$ 9 ! =mula above giv5 = ! cross-section ( any wire1 ! result is 7#a1jjj1jjj p\nds7 7#c4jc l7 7l amp]es #aa7 volts4 ,transposition ( ! factors 9 ?is la/ equation br+s x to ! =m1 p\nds 7#c4jc l amp]es #aa7 7#a1jjj1jjj volts71 :i* is ! g5]al =mula = ! total weight ( copp] conductors :5 l1 ! l5g? ( "o pair1 ! total amp]es fl[+1 & ! volts lo/ 9 ! conductors are kn[n = ei!r a cont9u\s-curr5t1 a s+le-phase1 or a two-phase f\r-wire l9e4 ,if ! value ( l1 #bjj1jjj1 ( amp]es1 #ajj1 & ( volts1 #b1jjj1 = ! transmission above consid]$ are sub/itut$ 9 ! =mula = total weight1 j f\nd1 ! result is p\nds 7#c4jc 7#bjj1jjj7 #ajj #aa7 7#a1jjj1jjj #b1jjj71 :i* r$uc$ to p\nds #ff1ffj1 ! weight ( copp] wire necess>y = ! transmission ) ei!r cont9u\s1 s+le-phase or two-phase curr5t4 ,) ?ree-phase curr5t ! weight ( copp] 9 ! l9e = ?is transmission w be #ge p] c5t ( ! #ff1ffj p\nds j f\nd4 ,"o or m two-wire circuits may be employ$ = ! cont9u\s curr5t or = ! s+le-phase transmission1 & if "o su* circuit is us$ ! weight = ea* ( ! two wires is obvi\sly #cc1ffj p\nds4 ,= a two-phase transmission two or m circuits ( two wires ea* w be us$1 & 9 ! case ( two circuits1 if all f\r ( ! wires are ( equal cross section1 z w\ld usually be ! case1 ! total weight ( ea* is #af1hcj p\nds4 ,if ! transmission is made ) "o ?ree-phase circuit1 ! weight ( ea* ( ! ?ree wires is #af1hcj p\nds1 & _! comb9$ weight1 #ej1dij p\nds ( copp]4 ,9 ea* ( ^! transmission l9es ! l5g? ( a s+le conductor 9 "o direction is #ajj1jjj feet1 or "o-half ( ! l5g? ( ! wires 9 a s+le two-wire circuit4 ,= ! two-wire l9e ! calculat$ weight ( ea* conductor am\nts to #ff1ffj #bjj #ccc4c p\nds p] #a1jjj feet4 ,= a two-phase f\r-wire l9e & also = a ?ree-phase ?ree-wire l9e1 ! weight ( ea* conductor is #af1hcj #ajj #afh4c p\nds p] #a1jjj feet4 ,on inspection ( a table ( weights = b>e copp] wires x may be se5 t a ,no4 #a-j ,b4 ,s4 gauge wire has a weight ( #cbj p\nds p] #a1jjj feet1 & be+ mu* ! ne>e/ size to ! calculat$ weight ( #ccc p\nds %\ld be select$ = ! two-wire circuit4 ,x may also be se5 t a ,no4 #c wire1 ) a weight ( #aei p\nds p] #a1jjj feet1 is ! size t comes ne>e/ to ! calculat$ weight ( #afh p\nds1 & %\ld !re=e be employ$ 9 ! ?ree-wire & ! f\r-wire circuits1 = two- & ?ree-phase transmissions4 ,ei!r a cont9u\s-curr5t1 s+le-phase1 two-phase1 or ?ree-phase transmission l9e may ( c\rse be split up into z _m circuits z desir$1 & ^! circuits may or may n be design$ to c>ry equal portions ( ! entire p[]4 ,9 ei!r case ! comb9$ weights ( ! sev]al circuits %\ld equal ^? above f\nd1 ! conditions z to p[]1 loss1 & l5g? ( l9e rema9+ con/ant4 ,x w be not$ t ! =mul = ! calculation ( ! circul> mils & = ! weight ( ! conductors 9 ! transmission l9e lead to ! selection ( ! same sizes ( wires1 z !y obvi\sly %\ld d4 ,sev]al laws gov]n+ ! relations ( volts lo/1 l5g? & weight ( l9e conductors1 may be readily d$uc$ f ! above =mul4 ,evid5tly ! circul> mils & weight ( l9e conductors v>y inv]sely ) ! numb] ( volts lo/ 9 !m :5 c>ry+ a giv5 curr5t1 s t d\bl+ ?is numb] ( volts r$uces ! circul> mils & weight ( conductors by "o-half4 ,if ! l5g? ( ! l9e *anges1 ! circul> mils ( ! requir$ conductors *ange directly ) x1 b ! weight ( ^! conductors v>ies z ! squ>e ( _! l5g?4 ,?us1 if ! l5g? ( ! l9e conductors is d\bl$1 ! cross-section 9 circul> mils ( ea* conductor is also d\bl$1 & ea* conductor is !re=e f\r times z heavy z be=e = ! same curr5t & loss 9 volts4 ,%\ld ! l5g? ( ! conductors & also ! numb] ( volts lo/ 9 !m be v>i$ at ! same rate1 ! circul> mils ( ea* conductor rema9 con/ant1 & its weight increases directly ) ! di/ance ( transmission4 ,?us1 ) ! same size ( l9e wire1 bo? ! numb] ( volts lo/ & ! total weight are twice z great = a #ajj- z = a fifty-mile transmission4 ,if ! total weight ( conductors is to be held con/ant1 !n ! numb] ( volts lo/ !re9 mu/ v>y z ! squ>e ( _! l5g?1 & _! circul> mils mu/ v>y inv]sely z ! l5g?4 ,s t if ! l5g? ( a transmission l9e is d\bl$1 ! circul> mils = conductors ( con/ant weight are divid$ by two1 & ! volts lo/ are f\r times z great z be=e4 ,ea* ( ^! rules assumes t ! watts & p]c5tage ( loss 9 ! l9e are con/ant4 ,! above pr9ciples & =mul apply to ! design ( transmission l9es = ei!r cont9u\s or alt]nat+ curr5ts1 b :]e ! alt]nat+ curr5t is employ$ c]ta9 additional factors %\ld be consid]$4 ,"o ( ^! factors is inductance1 by :i* is meant ! c\nt]-electromotive =ce t is always pres5t & oppos$ to ! regul> voltage 9 an alt]nat+ curr5t circuit4 ,"o effect ( inductance is to cut d[n ! voltage at t end ( ! l9e :]e ! p[] is deliv]$ to a sub-/ation1 j z is also done by ! ohmic resi/ance ( ! l9e conductors4 ,betwe5 ! loss ( voltage due to l9e resi/ance & ! loss due to inductance !re is ! v important diff]5ce t ! =m] repres5ts an actual conv]sion ( electrical en]gy into heat1 :ile ! latt] is simply ! loss ( pressure )\t any mat]ial decrease 9 ! am\nt ( en]gy4 ,:ile ! loss ( en]gy 9 a transmission l9e dep5ds directly on its resi/ance1 ! loss ( pressure due to inductance dep5ds on ! diamet] ( conductors )\t reg>d to _! resi/ance1 on ! l5g? ( ! circuit1 ! di/ance betwe5 ! conductors1 & on ! frequ5cy or numb] ( cycles p] second ?r\gh :i* ! curr5t passes4 ,z a result ( ^! facts1 x is n desirable or ev5 practicable to use inductance z a factor 9 ! calculation ( ! resi/ance or weight ( a transmission l9e4 ,on transmission l9es1 z ord9>ily con/ruct$1 ! loss ( voltage due to inductance g5]ally ranges betwe5 #be & #ajj p] c5t ( ! numb] ( volts lo/ at full load because ( ! resi/ance ( ! conductors4 ,?is loss ?r\gh inductance may be l[]$ by r$uc+ ! diamet] ( individual wires1 ?\gh ! resi/ance ( all ! circuits conc]n$ 9 ! transmission rema9s ! same1 by br++ ! wires ne>] toge!r & by adopt+ small] frequ5cies4 ,9 practice ! volts lo/ ?r\gh inductance are comp5sat$ = by op]at+ g5]ators or trans=m]s 9 ! p[]-plant at a voltage t insures ! deliv]y ( en]gy 9 ! receiv+-/ation at ! requir$ pressure4 ,?us1 9 a c]ta9 case1 x may be desirable to transmit en]gy ) a maximum loss ( t5 p] c5t 9 ! l9e at full load1 due to ! resi/ance ( ! conductors1 :5 ! effective voltage at ! g5]ator end ( ! l9e is #aj1jjj1 s t ! pressure at ! receiv+-/ation w be #i1jjj volts4 ,if x appe>s t ! loss ( pressure due to inductance on ?is l9e w be #a1jjj volts1 !n ! g5]ators %\ld be op]at$ at #aa1jjj volts1 :i* w provide = ! loss ( #a1jjj volts by inductance1 leave an effective voltage ( #aj1jjj on ! l9e1 & all[ ! deliv]y ( en]gy at ! sub-/ation ) a pressure ( #i1jjj volts1 :5 !re is a t5-p]c5t loss ( p[] due to ! l9e resi/ance4 ,inductance n only sets up a c\nt]-electromotive =ce 9 ! l9e1 :i* r$uces ! voltage deliv]$ to x by g5]ators or trans=m]s1 b also causes a l>g] curr5t to fl[ 9 ! l9e ?an is indicat$ by ! division ( ! numb] ( watts deliv]$ to x by ! virtual voltage ( deliv]y4 ,! am\nt ( curr5t increase dep5ds on bo? ! inductance ( ! l9e itself & also on ! "* ( its connect$ app>atus4 ,9 a sy/em ) a mix$ load ( lamps & motors !re is q c]ta9 to be "s inductance1 b x is v h>d to pr$et]m9e its exact am\nt4 ,exp]i5ce ) su* sy/ems %[s1 h[ev]1 t ! increase ( l9e curr5t due to inductance is (t5 n above five & usually less ?an t5 p] c5t ( ! curr5t t w\ld fl[ if !re 7 no inductance4 ,to provide = ! fl[ ( ?is additional curr5t1 due to inductance1 )\t an increase ( ! loss 9 volts because ( ohmic resi/ance1 ! cross section ( ! l9e conductors mu/ be enl>g$ by a p]c5tage equal to t ( ! additional curr5t4 ,?is means t 9 an ord9>y case ( a transmission ) ei!r s+le1 two1 or ?ree-phase alt]nat+ curr5t1 ! circul> mils ( ea* l9e wire1 z comput$ ) ! =mul above giv51 %\ld be increas$ by five to t5 p] c5t4 ,su* increase 9 ! cross section ( wires ( c\rse c>ries ) x a l rise 9 ! total weight ( ! conductors = ! transmission4 ,if wire ( ! cross section comput$ ) ! =mul is employ$ = ! alt]nat+ curr5t transmission1 inductance 9 an ord9>y case w raise ! assum$ l9e loss ( p[] by five to t5 p] c5t ( :at x w\ld be if no inductance exi/$4 ,?us1 ) conductors calculat$ by ! =mul = a p[] loss ( t5 p] c5t at full load1 inductance 9 an ord9>y case w\ld raise ?is loss to some:]e betwe5 #aj4e & elev5 p] c5t4 ,z a rule x may !re=e be said t inductance w seldom increase ! weight ( l9e conductors1 or ! loss ( p[] !re91 by m ?an t5 p] c5t4 ,:5 an alt]nat+ curr5t fl[s along a conductor its d5sity is n uni=m 9 all p>ts ( ea* cross section1 b ! curr5t d5sity is lea/ at ! c5tre ( ! conductor & increases t[>d ! outside surface4 ,?is unequal di/ribution ( ! alt]nat+ curr5t ov] ea* cross section ( a conductor ?r\gh :i* x is pass+ increases ) ! diamet] or ?ickness ( ! conductor & ) ! frequ5cy ( ! alt]nat+ curr5t4 ,by reason ( ?is action ! ohmic resi/ance ( any conductor is some:at great] = an alt]nat+ ?an = a cont9u\s curr5t1 because ! full cross section ( ! conductor _c be utiliz$ ) ! =m] curr5t4 ,=tunately1 ! practical importance ( ?is unequal di/ribution ( alt]nat+ curr5t ov] ea* cross section ( its conductor is usually slight1 s f> z ! sizes ( wires = transmission l9es are conc]n$1 because ! usual frequ5cies ( curr5t & diamet]s ( conductors conc]n$ are n great en\gh to give ! effect m5tion$ a l>ge num]ical value4 ,?us1 sixty cycles p] second is ! highe/ frequ5cy commonly employ$ = ! curr5t on transmission l9es4 ,) a #d-j wire1 & ! curr5t frequ5cy nam$1 ! increase 9 ! ohmic resi/ance = alt]nat+ ov] t = cont9u\s curr5t does n rea* "o-half ( "o p] c5t4 ,hav+ calculat$ ! circul> mils ( weight ( a transmission l9e by ! =ego+ =mul1 x appe>s t ! only mat]ial increase ( ?is weight requir$ by ! use ( alt]nat+ curr5t is t due to inductance4 ,?is increase _c be calculat$ exactly be=eh& because ( ! unc]ta9 elem5ts 9 future loads1 b exp]i5ce %[s t x is seldom m ?an t5 p] c5t ( ! calculat$ size or weight ( conductors4 ,,*apt] ,,xvii4 ,,selection ,,( ,,transmission ,,circuits4 ,maximum p[]1 voltage1 loss1 & weight ( conductors hav+ be5 fix$ = a transmission l9e1 ! numb] ( circuits t %all make up ! l9e1 & ! relations ( ^! circuits to ea* o!r1 rema9 to be det]m9$4 ,9 practice wide diff]5ces exi/ z to ! numb] & relations ( circuits on a s+le transmission l9e betwe5 two po9ts4 ,cases illu/rat+ ?is fact are ! #adg-mile transmission f ,electra p[]-h\se to ,san ,francisco & ! #fe-mile transmission betwe5 ,caon ,f]ry1 on ! ,miss\ri ,riv] & ,butte1 ,mont4 ,at ! ,electra plant ! g5]ator capacity is #aj1jjj kil[atts1 & ! transmission to ,san ,francisco is c>ri$ out ov] a s+le pole l9e t c>ries "o circuit compos$ ( ?ree alum9um conductors1 ea* ) an area 9 cross section ( #dga1jjj circul> mils4 ,f ! g5]ators at ,caon ,f]ry1 :i* h an aggregate capacity ( #g1ejj kil[atts1 a "p ( ! en]gy goes to ,hel5a ov] a sep>ate l9e1 & ! transmission to ,butte goes ov] two pole l9es t are #dj feet ap>t4 ,ea* ( ^! two pole l9es c>ries a s+le circuit compos$ ( ?ree copp] conductors1 & ea* conductor has a cross section ( #aje1fjj circul> mils4 ,! diff]5ce 9 practice illu/rat$ by ^! two plants is fur!r br\ght out by ! fact t _! voltages are n f> ap>t1 z ! ,caon ,f]ry & ,butte l9e op]ates at #ej1jjj1 & ! ,electra & ,san ,francisco l9e at #fj1jjj volts4 ,economy 9 ! con/ruction ( a transmission l9e po9ts /rongly to ! use ( a s+le circuit1 because ?is means only "o l9e ( poles1 usually b "o cross-arm = ! p[] wires p] pole1 ! lea/ possible numb] ( p9s & insulators1 & ! smalle/ am\nt ( labor = ! erection ( ! conductors4 ,9 favor ( a s+le circuit !re is also ! argum5t ( greate/ me*anical /r5g? 9 ea* conductor1 s9ce ! s+le circuit is to h ! same weight z t ( all ! circuits t may be adopt$ 9 its place4 ,:]e ea* conductor ( ! s+le circuit w\ld h a cross section ( less ?an #hc1fij circul> mils1 if ( copp]1 correspond+ to a ,no4 #a ,b4 ,s4 gauge wire1 ! argum5t z to me*anical /r5g? is ( especial =ce1 s9ce two equal circuits in/ead ( "o1 9 ! case :]e "o circuit ( ,no4 #a wires w\ld h ! requir$ weight1 r$uce ! size ( ea* conductor to ,no4 #d wire1 ( #da1gdj circul> mils cross section1 & ?is is ! smalle/ wire t x is practicable to use on long l9es = me*anical reasons4 ,oppos$ to ^! argum5ts = a s+le circuit are ^? bas$ on ! suppos$ great] reliability ( two or m circuits1 _! great] ease ( repair1 _! m effective means ( regulation1 & ! influ5ce on inductance ( a r$uction 9 ! size ( conductors4 ,9 spite ( ! consequ5t r$uction 9 ! size ( ea* conductor1 ! use ( two or m sep>ate circuits = ! same transmission is sometimes ?\ght to increase its reliability1 because 9 case ( a break or %ort-circuit on "o ( ! circuits ! o!r w /ill be available4 ,breaks 9 transmission conductors are due ei!r to me*anical /ra9s alone1 z w9d pressure1 ! fall+ ( trees1 or ! accumulation ( ice1 or else to an arc betwe5 ! conductors t t5ds to melt !m at "s po9t4 ,z a small] conductor breaks or melts m readily ?an a l>ge "o1 ! use ( two or m circuits in/ead ( a s+le circuit t5ds to increase tr\bles ( ?is sort4 ,x ?us seems t :ile two or m circuits give a great] *ance ( cont9u$ op]ation aft] a break 9 a conductor actually occurs1 ! use ( a s+le circuit ) l>g] conductors makes any break less probable4 ,:5 repairs mu/ be made on a transmission l9e1 z 9 replac+ a brok5 insulator or sett+ a pole 9 ! place ( "o t has burn$1 x is c]ta9ly conv5i5t to h two or m circuits s t "o may be out ( use :ile ! repairs on x are made4 ,x is practicable1 h[ev]1 to make su* repairs on any high-voltage circuit1 ev5 :5 x is 9 use1 provid$ ! conductors are spac$ s f> ap>t t !re is no *ance ( mak+ a contact or />t+ an arc betwe5 !m4 ,to get su* di/ance betwe5 conductors !re %\ld be only "o circuit p] pole1 & ev5 !n m room %\ld be provid$ = t circuit ?an is common 9 ?is type ( con/ruction4 ,on ea* ( ! two pole l9es betwe5 ,caon ,f]ry & ,butte !re is a s+le circuit ( ?ree conductors arrang$ 9 triangul> =m1 two at ! opposite ends ( a cross-arm & "o at ! top ( ! pole1 & ! di/ance f ea* conductor ( a circuit to ei!r ( ! o!r two is #f4e feet4 ,?is di/ance betwe5 conductors is p]haps z great z t on any transmission circuit n[ 9 use1 b x seems too small to make repairs on ! circuit reasonably safe :5 x is 9 op]ation at a pressure ( #ej1jjj volts4 ,!re seems to be no good reason :y ! di/ance betwe5 ! conductors ( a s+le circuit to :i* a pole l9e is devot$ might n be increas$ to z mu* z t5 feet1 at ! slightly great] exp5se ( long] cross-arms4 ,) z mu* z t5 feet betwe5 conductors1 & special tools ) long wood5 h&les to grasp ^! conductors1 !re %\ld be no s]i\s dang] ab\t ! repair ( ev5 #fj1jjj-volt l9es :5 9 op]ation4 ,z ! #fj1jjj-volt l9e betwe5 ,electra & ,san ,francisco consi/s ( only "o circuit1 x seems t repairs on x mu/ be contemplat$ dur+ op]ation4 ,ano!r example ( a high-voltage transmission c>ri$ out ) a s+le circuit is t betwe5 ,%aw9igan ,falls & ,montreal1 a di/ance ( eighty-five miles4 ,9 ?is case ! circuit is made up ( ?ree alum9um conductors1 ea* ( :i* has an area 9 cross section ( #ahc1gej circul> mils1 & ^! conductors are locat$ five feet ap>t1 "o at ! top ( ea* pole1 & two at ! ends ( a cross-arm bel[4 ,?is s+le circuit is 9 regul> op]ation at #ej1jjj volts = ! supply ( light & p[] 9 ,montreal1 & x is h>d to see h[ repairs :ile !re is curr5t on ! l9e are to be avoid$4 ,inductance v>ies ) ! ratio betwe5 ! diamet] ( ! wires 9 any circuit & ! di/ance betwe5 ^! wires1 b z inductance simply raises ! voltage t mu/ be deliv]$ by g5]ators or trans=m]s1 & does n repres5t a loss ( en]gy1 x may g5]ally be giv5 b little weight 9 select+ ! numb] ( circuits1 ! di/ance betwe5 conductors1 & ! size ( ea* conductor4 ,if two or m circuits ) small] conductors h a comb9$ resi/ance 9 multiple equal to t ( a s+le circuit ) l>g] conductors1 ! loss ( voltage due to inductance may be great] on ! s+le circuit ?an ! correspond+ loss on ! multiple circuits1 b ! advantages due to ! s+le circuit may m ?an comp5sate = ! high] pressure at g5]ators or trans=m]s4 ,t su* advantages h be5 ?\ght to exi/ 9 actual con/ruction may be se5 f ! fact t ! #adg-mile l9e f ,electra p[]-h\se to ,san ,francisco1 & ! #hc-mile l9e f ,%aw9igan ,falls to ,montreal1 are compos$ ( "o circuit ea*4 ,z inductance increases directly ) ! l5g? ( circuits1 ^! v long l9es are especially subject to its influ5ce1 yet x 0 ?\ght t ! advantages ( a s+le circuit m ?an (fset its disadvantages 9 ea* case4 ,:]e sev]al sub-/ations1 widely sep>at$1 are to be suppli$ ) en]gy by ! same transmission l9e1 ano!r argum5t exi/s = ! division ( ! l9e conductors into m ?an "o circuit1 s t !re may be an indep5d5t circuit to ea* sub-/ation4 ,z ! pressure = local di/ribution l9es mu/ be regulat$ at ea* sub-/ation1 x is q an advantage to h a sep>ate transmission circuit betwe5 ea* sub-/ation & ! p[] plant1 s t ! voltage on ea* circuit at ! p[]-h\se may be adju/$ z ne>ly z possible to ! requirem5ts ( its sub-/ation4 ,an int]e/+ illu/ration ( ?is practice may be not$ 9 ! design ( transmission circuits = ! l9e betwe5 ,spi] ,falls on ! ,hudson ,riv] & ! cities ( ,s*5ectady1 ,troy1 & ,albany1 locat$ betwe5 ?irty & =ty miles to ! s\?1 :i* passes ?r\gh ,s>atoga & ,ball/on on ! way4 ,:5 ?is transmission l9e is complet$1 f\r ?ree-phase circuits1 "o ( ,no4 #j & ?ree ( ,no4 #jjj copp] wire1 w run to ! ,s>atoga swit*-h\se f ! g5]at+ plant at ! ,falls1 a di/ance ( "s eight miles4 ,f ?is swit*-h\se two circuits ( ,no4 #j conductors g to ! ,s>atoga sub-/ation1 a little m ?an "o mile away1 two circuits ( ,no4 #jjj wires run to ! ,wat]vliet sub-/ation1 across ! riv] f ,troy & ?irty-five miles f ! g5]at+ /ation1 & "o circuit ( ,no4 #j & "o circuit ( ,no4 #jjj wires are c>ri$ to ,s*5ectady1 ?irty miles f ,spi] ,falls1 pass+ ?r\gh & supply+ ! ,ball/on sub-/ation on ! way4 ,o!r circuits connect ! sub-/ation at ,wat]vliet ) t at ,s*5ectady & ) ! wat]-p[] /ation at ,me*anicsville4 ,f ! ,wat]vliet sub-/ation second>y l9es run to sub-/ations t control ! local di/ribution ( light & p[] 9 ,albany & ,troy4 ,?is network ( transmission circuits 0 made desirable by ! conditions ( ?is case1 :i* include ! g5]al supply ( light & p[] 9 ?ree l>ge & sev]al small] cities1 ! op]ation ( ?ree l>ge electric railway sy/ems1 & ! deliv]y ( ?\s&s ( horse-p[] = ! motors 9 a great manufactur+ plant4 ,9 n e transmission sy/em ) diff]5t & widely scatt]$ loads x is ?\ght desirable to provide m ?an "o ma9 circuit4 ,?us1 ! s+le circuit eighty-?ree miles long t transmits en]gy f ,%aw9igan ,falls to ,montreal is design$ to supply p[] also 9 "s small] places on ! way4 ,s aga91 ! #adg-mile circuit f ,electra p[]-h\se to ,san ,francisco passes ?r\gh a doz5 or m small] places1 includ+ ,/ockton1 & is tapp$ ) side l9es t run to ,oakl& & ,san ,jos4 ,9 cases l ?is1 :]e v long l9es run ?r\gh l>ge numb]s ( cities & t[ns t soon] or lat] require s]vice1 x is obvi\sly impracticable to provide a sep>ate circuit = ea* c5tre ( local di/ribution4 ,x may well be 9 su* a case t a s+le ma9 transmission circuit connect$ to a long l9e ( sub-/ations w repres5t ! be/ possible solution ( ! problem4 ,at ! p[]-h\se end ( su* a circuit ! voltage w naturally be regulat$ to suit t sub-/ation :]e ! load is ! mo/ important or exact+1 & ea* ( ! o!r sub-/ations w be left to d all ( ! regulat+ = its own load4 ,illu/ration3 ,,fig4 #gf4--;,connections at ,wat]vliet ,sub-/ation on ,spi] ,falls ,l9e4 ,! great] ! total loss ( voltage on a transmission l9e supply+ sub-/ations t are scatt]$ along mu* ( its l5g?1 ! l>g] w be ! fluctuations ( voltage t mu/ be comp5sat$ = at all ( ! sub-/ations save "o1 "u *ang+ loads1 if only "o circuit is employ$ betwe5 ! p[]-plant & ^! sub-/ations4 ,suppose1 = example1 t a transmission l9e #ajj miles long is compos$ ( a s+le circuit1 & supplies two sub-/ations1 "o locat$ #ej miles & ! o!r #ajj miles f ! p[]-plant4 ,assume at fir/ t !re is no load :atev] at ! int]m$iate sub-/ation4 ,if ! s+le transmission circuit op]ates ) #ej1jjj volts at ! p[]-plant1 & #de1jjj volts at ! sub-/ation #ajj miles away :5 !re is a full load !re1 correspond+ to a loss ( t5 p] c5t1 !n ! pressure at ! int]m$iate sub-/ation w be #dg1ejj volts4 ,if1 n[1 ! load at ! sub-/ation #ajj miles f ! p[]-h\se drops to a po9t :]e ! entire l9e loss is only #a1jjj volts1 & ! pressure at ! g5]at+ plant is l[]$ to #df1jjj volts s z to ma9ta9 #de1jjj volts at ! m di/ant sub-/ation1 !n ! pressure at ! int]m$iate sub-/ation w be #de1ejj volts1 or #b1jjj volts less ?an x 0 be=e4 ,if ! loss on ! entire l9e at full load 7 only five p] c5t1 mak+ ! voltage at ! sub-/ation #ajj miles away #dg1ejj :5 t at ! g5]at+ /ation is #ej1jjj1 !n ! pressure at ! int]m$iate sub-/ation w be #dh1gej volts4 ,^u a r$uction ( ! loss on ! entire l5g? ( l9e to "o-fif? ( its maximum am\nt1 or to #ejj volts1 ! pressure at ! g5]at+ /ation mu/ be r$uc$ to #dh1jjj volts1 if t at ! m di/ant sub-/ation is to be held con/ant at #dg1ejj4 ,at ! int]m$iate sub-/ation ! pressure w !n be #dg1gej volts1 or #a1jjj volts less ?an x 0 at full load4 ,f ^! two examples x may be se5 t ! ext5t ( pressure v>iation at ! int]m$iate sub-/ation w dep5d directly on ! maximum l9e loss1 if ! regulation at ! g5]at+ /ation is su* z to ma9ta9 a con/ant voltage at ! sub-/ation #ajj miles away4 ,illu/ration3 ,,fig4 #gg4--,sections ( ,swit*-h\se on ,new ,hamp%ire ,traction ,sy/em4 ,all ! =ego+ has assum$ no load to be connect$ at ! int]m$iate sub-/ation1 & ) a load !re ! fluctuations ( pressure w ( c\rse dep5d on its am\nt z well z on ! load at ! m di/ant sub-/ation4 ,"o ( ! /ronge/ reasons = ! use ( two or m circuits 9 ! same transmission l9e arises f ! rapid fluctuations ( load :]e l>ge /ation>y motors or an electric railway sy/em is op]at$4 ,:5 a transmission l9e mu/ c>ry a load ( /ation>y or railway motors1 x is a common practice to divide ! l9e into at lea/ two circuits1 & to devote "o circuit exclusively to railway or motor "w & ano!r to light+1 at any "o "t4 ,9 "s cases ?is division ( ! transmission sy/em into two p>ts1 "o devot$ to ! light+ & ! o!r to ! motor load1 is c>ri$ out n only z to ! sub-/ation app>atus & ! l9e1 b also z to ! trans=m]s1 g5]ators1 wat]-:eels1 & ev5 ! p5/ocks at ! p[]-plant4 ,x is possible ev5 to c>ry ?is division ( ! transmission sy/em /ill fur!r1 & to sep>ate ei!r ! motor or ! light+ load1 or bo?1 into sections1 & !n to devote a di/9ct transmission circuit1 gr\p ( trans=m]s1 g5]ator1 & wat]-:eel to ! op]ation ( ea* section4 ,an example ( ! complete division ( g5]at+ & transmitt+ app>atus into indep5d5t units may be not$ 9 ! case ( ! sy/em t supplies light & p[] 9 ,portl&1 ,me41 f a g5]at+ plant on ! ,presumpscot ,riv]1 ?irte5 miles away4 ,at ?is /ation f\r /eel p5/ocks1 ea* provid$ ) a sep>ate gate at ! =ebay wall1 br+ wat] to z _m pairs ( :eels1 & ea* pair ( :eels drives a direct-connect$ g5]ator4 ,f\r ?ree-phase circuits connect ! g5]at+ plant ) ! sub-/ation at ,portl&1 & ea* circuit betwe5 ! g5]at+ plant & a trans=m]-h\se outside ! bus9ess section ( ! city is made up ( ,no4 #b solid s(t-drawn copp] wires4 ,ea* ( ^! f\r sets ( app>atus1 f head-gate to sub-/ation1 is usually op]at$ indep5d5tly ( ! o!rs1 & supplies ei!r ! motor load or a "p ( ! electric light+4 ,9 ?is way *anges 9 ! am\nt ( "o section ( ! load cause no fluctuation ( ! voltage on ! o!r sections4 ,at ,man*e/]1 ,n4 ,h41 ! sub-/ation receives en]gy f f\r wat]-p[] plants1 & is provid$ ) two sets ( l[-t5sion1 #b1cjj-volt1 ?ree-phase bus-b>s1 "o set ( ^! bus-b>s be+ devot$ to ! op]ation ( ! local electric railway sy/em1 & ! o!r set to ! supply ( lamps & /ation>y motors4 ,ea* set ( ^! bus-b>s is divid$ into a numb] ( sections1 & by means ( ^! sections diff]5t transmission circuits are devot$ to diff]5t portions ( ! light+ & motor loads4 ,z ?ree ( ! f\r wat]-p[] plants are connect$ to ! sub-/ation by two circuits ea*1 ! division ( loads 9 ?is case is (t5 c>ri$ cle> back to ! g5]ators1 "o g5]ator 9 a p[]-h\se be+ op]at$1 = in/ance1 on railway "w & ano!r on a light+ load at ! same "t4 ,?is plan has ! obvi\s advantage t mu* ( ! regulation = ! sev]al p>ts ( ! entire load may be done at ! g5]ators1 ?us r$uc+ ! am\nt ( regulation necess>y at ! sub-/ation1 & t fluctuat+ motor loads d n affect ! lamps4 ,9 ?is case ! conductors ( ! sev]al transmission circuits are all ( mod]ate size1 & ! division ( ! l9es 0 evid5tly adopt$ = purposes ( regulation1 r ?an to r$uce ! am\nt ( inductance4 ,?us ! l9e betwe5 ,gregg's ,falls & ! sub-/ation1 a di/ance ( six miles1 is made up ( "o ?ree-phase circuit ( ,no4 #d & "o circuit ( ,no4 #f b>e copp] wires4 ,! f\rte5-mile l9e betwe5 ! plant at ,g>v9's ,falls & ! sub-/ation1 ! longe/ ( ! f\r transmissions1 is made up ( two ?ree-phase circuits1 ea* compos$ ( ,no4 #j b>e copp] wires4 ,9 ! case ( ! ,gregg's ,falls plant ! subdivision ( ! l9e has gone fur!r ?an t ( ! g5]at+ equipm5t1 = ! /ation !re conta9s only a s+le g5]ator1 ! rat+ be+ #a1bjj kil[atts1 :ile two circuits run !nce to ! sub-/ation4 ,ano!r in/ance %[+ ext5sive subdivision ( a l9e into sep>ate circuits may be not$ 9 ! sev5-mile transmission f ,montmor5cy ,falls to ,quebec1 ,canada1 :]e sixte5 conductors1 ea* ,no4 #j copp] wire1 make up f\r two-phase circuits t connect a plant ( #b1djj kil[atts capacity ) its sub-/ation4 ,su* multiplication ( transmission circuits has "s advantages f ! /&po9t ( regulation1 b !re are good reasons = limit+ x to r %ort l9es1 :]e x is1 9 fact1 almo/ exclusively f\nd4 ,on v long l9es ! use ( num]\s circuits compos$ ( r small conductors w\ld obvi\sly increase ! con/ant exp5se ( inspection & repairs & add mat]ially to unc]ta9ty ( ! s]vice4 ,v few1 if any1 transmission l9es ( z mu* z tw5ty-five miles 9 l5g? are divid$ into m ?an two circuits1 & 9 sev]al in/ances l9es ( sup]lative l5g? h only a s+le circuit ea*4 ,! greate/ s+le p[] transmission 9 ! _w1 t betwe5 ,niag>a ,falls & ,buffalo1 is c>ri$ out ) two pole l9es1 "o ( :i* is ab\t tw5ty & ! o!r ab\t tw5ty-?ree miles long4 ,! long] pole l9e1 :i* is also ! old]1 c>ries two ?ree-phase circuits1 ea* ( :i* is made up ( ?ree #cej1jjj circul> mil copp] conductors4 ,! %ort] pole l9e c>ries a s+le ?ree-phase circuit compos$ ( alum9um conductors1 ea* ( :i* has an area 9 cross section ( #ejj1jjj circul> mils4 ,9 electrical conductivity ! alum9um circuit is int5d$ to be equal to ea* ( ! two t are compos$ ( copp]4 ,accord+ to ! description ( ! ,niag>a ,falls & ,buffalo transmission sy/em 9 vol4 xviii41 ,a4 ,i4 ,e4 ,e41 pages #eah to #ebg1 ea* ( ^! ?ree circuits is design$ to transmit ab\t #g1ejj kil[atts1 & ! maximum p[] transmitt$ up to ,augu/1 #aija1 0 #ae1fjj kil[atts1 or ab\t ! calculat$ capacity ( two ( ! circuits4 ,accord+ to ! description j m5tion$1 ! transmission circuits us$ to supply en]gy = use at ,buffalo are regul>ly op]at$ 9 p>allel1 & ?is is also true ( ! g5]ators & ! /ep-d[n trans=m]s1 ?\gh ! uses to :i* ?is en]gy is appli$ include light+1 l>ge /ation>y motors1 & ! electric railway sy/em4 ,app>atus 9 ! g5]at+ /ation at ,niag>a ,falls & 9 ! t]m9al-h\se ne> ! city limits ( ,buffalo is s arrang$1 h[ev]1 t two ( ! #c1gej kil[att g5]ators & eight /ep-up trans=m]s at ! p[]-h\se1 toge!r ) "o transmission circuit & ?ree /ep-d[n trans=m]s 9 ! t]m9al-h\se at ,buffalo1 may be op]at$ indep5d5tly ( all ! o!r app>atus4 ,z already po9t$ out1 ! use ( sep>ate circuits = ea* sub-/ation1 & = light+ & p[] loads at ea* sub-/ation 9 v long transmission sy/ems1 is (t5 impracticable4 ,ev5 9 comp>atively %ort transmissions ! multiplication ( circuits & ! use ( r small & me*anically weak conductors increas$ ! fir/ co/ ( in/allation & ! subsequ5t exp5se ( inspection & repairs4 ,an objection to op]ation ) a s+le circuit 9 a transmission l9e t supplies widely sep>at$ sub-/ations ) light+1 p[]1 & railway loads is ! consequ5t difficulty ( pressure regulation on ! di/ribution l9es at ea* sub-/ation4 ,su* a transmission l9e necess>ily deliv]s en]gy at diff]5t & fluctuat+ voltages at ! sev]al sub-/ations1 & ^! fluctuations are ( c\rse reproduc$ on ! second>y side ( ! /ep-d[n trans=m]s4 ,=tunately1 h[ev]1 ! use ( syn*ron\s motor g5]ators1 ei!r 9 place ( or 9 connection ) /atic trans=m]s1 goes f> to solve ! problem ( pressure regulation = di/ribution circuits suppli$ ) en]gy f transmission l9es4 ,?is is due to ! well-kn[n fact t ) con/ant frequ5cy ! spe$ ( rotation = a syn*ron\s motor is con/ant )\t reg>d to fluctuations 9 ! appli$ voltage or *anges 9 its load4 ,) a con/ant spe$ at ! motor & its connect$ g5]ator x is ( c\rse easy to deliv] curr5t at con/ant voltage to ! di/ribution l9es4 ,?is con/ancy ( spe$ makes ! syn*ron\s motor g5]ator a favorite 9 l>ge transmission sy/ems ) bo? p[] & light+ loads4 ,! satisfactory light+ s]vice 9 ,buffalo1 op]at$ ) en]gy transmitt$ f ,niag>a ,falls1 seems to be due 9 "s measure to ! use ( syn*ron\s motor g5]ators at ! sub-/ation 9 ,buffalo1 :5ce light+ circuits are suppli$4 ,z above /at$1 ! ?ree circuits t make up ! transmission l9e betwe5 ,niag>a ,falls & ,buffalo are op]at$ 9 multiple1 & 9 ! latt] place !re is a l>ge load ( bo? railway & /ation>y motors4 ,z ! ?ree circuits are op]at$ 9 multiple1 !y ( c\rse am\nt to only a s+le circuit s f> z fluctuations ( voltage due to *anges 9 ^! sev]al sorts ( loads are conc]n$4 ,accord+ to vol4 xviii41 ,a4 ,i4 ,e4 ,e41 pages #abe & foll[+1 ! load on ! transmission sy/em at ,buffalo 9 #aija 0 made up ( ab\t #g1jjj horse-p[] 9 railway motors1 #d1jjj horse-p[] 9 induction motors1 & #d1jjj horse-p[] divid$ up betwe5 s]ies arc lamps1 con/ant pressure inc&esc5t lamps1 & cont9u\s curr5t motors4 ,! railway load is op]at$ ?r\gh /ep-d[n trans=m]s & rot>y conv]t]s4 ,! induction motors are connect$ ei!r to ! #b1jjj-volt second>y circuits ( ! /ep-d[n trans=m]s or to s]vice trans=m]s suppli$ by ^! circuits4 ,on ^! railway & /ation>y motor loads !re is ( c\rse no necessity = close pressure regulation4 ,s]ies arc lamps are op]at$ ?r\gh /ep-d[n trans=m]s & syn*ron\s motors direct-connect$ to con/ant cont9u\s curr5t dynamos4 ,cont9u\s curr5t /ation>y motors draw p[] f ! transmission l9es ?r\gh /ep-d[n trans=m]s & rot>y conv]t]s1 l ! railway load4 ,= ! #b1bjj volt circuits t supply s]vice trans=m]s = comm]cial arc & inc&esc5t light+ ! transmitt$ en]gy passes ?r\gh /ep-d[n trans=m]s & syn*ron\s motor-g5]ators4 ,^! motor-g5]ators raise ! frequ5cy f tw5ty-five to sixty cycles p] second4 ,f9ally ! cont9u\s curr5t ?ree-wire sy/em = inc&esc5t light+ at ab\t #bej volts betwe5 outside wires is op]at$ ?r\gh /ep-d[n trans=m]s & syn*ron\s motors direct-connect$ to cont9u\s curr5t g5]ators4 ,= ?is la/-nam$ s]vice rot>y conv]t]s 7 at fir/ tri$1 b 7 f\nd to be impracticable because voltage fluctuations on ! transmission l9e 7due l>gely to ! railway & motor loads7 7 reproduc$ on ! cont9u\s-curr5t circuits by ! rot>y conv]t]s4 ,s9ce ! adoption ( motor-g5]ators ?is fluctuation ( ! s]vice voltage is no long] pres5t4 ,ano!r case 9 :i* syn*ron\s motor-g5]ators deliv] p[] f a transmission l9e t c>ries bo? a light+ & a motor load is t ( ! ,%aw9igan sub-/ation 9 ,montreal4 ,at ?is sub-/ation ! #he-mile transmission l9e f ! g5]at+ plant at ,%aw9igan ,falls t]m9ates4 ,z already po9t$ out1 ?is l9e is compos$ ( a s+le ?ree-phase circuit ( alum9um conductors1 ea* ( :i* has a cross section ( #ahc1gej circul> mils4 ,9 ! ,montreal sub-/ation ! ?irty-cycle1 ?ree-phase curr5t f ,%aw9igan ,falls is deliv]$ to trans=m]s t l[] ! voltage to #b1cjj4 ,! curr5t !n goes to five syn*ron\s motor-g5]ators ( #a1bjj horse-p[] capacity ea*1 & is !re conv]t$ to sixty-?ree cycles p] second1 two-phase1 at ! same voltage4 ,?is conv]t$ curr5t passes onto ! di/ribution l9es ( ! local electrical supply sy/em 9 ,montreal1 :i* also draws en]gy f two o!r wat]-p[] plants1 & is devot$ to light+1 /ation>y motors1 or to ! /reet railway "w1 z may be requir$4 ,?\gh sep>ate local di/ribution circuits are devot$ to ^! sev]al loads1 ! fluctuations 9 ! /ation>y & railway motor "w necess>ily react on ! voltage ( ! transmission l9e & trans=m]s at ! sub-/ation4 ,by ! use ( ! syn*ron\s motor-g5]ators ! light+ circuits are protect$ f ^! pressure v>iations4 ,z ! numb]s ( sub-/ations at diff]5t po9ts on long transmission l9es increase1 & /ation>y motor & railway loads at ea* become m common1 x is to be expect$ t ! use ( syn*ron\s motor-g5]ators = light+ s]vice w be mu* m frequ5t ?an at pres5t4 ,) su* use !re w disappe> "o ( ! reasons = ! multiplication ( transmission circuits4 ,illu/ration3 ,,fig4 #gh4--,transf] ,swit*es at ,s>atoga ,swit*-h\se on ,spi] ,falls ,l9e4 ,:]e sev]al transmission circuits connect a g5]at+ plant ) a s+le sub-/ation1 or ) sev]al sub-/ations 9 ! same g5]al direction1 x is desirable to h swit*es s arrang$ t two or m circuits may be comb9$ z "o1 or s t any circuit t ord9>ily op]ates a c]ta9 load or sub-/ation may be devot$ to ano!r :5 occasion requires4 ,= ?is purpose transf] swit*es on ea* circuit are necess>y at g5]at+ plants1 sub-/ations1 & (t5 at swit*-h\ses4 ,^! transf] swit*es w ord9>ily be ( ! knife type1 & int5d$ = manual op]ation :5 ! circuits to :i* !y are connect$ are n 9 use4 ,z su* swit*es are expos$ to ! full voltage ( transmission1 ! insulation ( _! conduct+ p>ts %\ld be v high4 ,9 ! ext5sive transmission sy/em betwe5 ! p[]-plants at ,spi] ,falls & ,me*anicsville & ! sub-/ations at ,troy1 ,albany1 & ,s*5ectady1 ,n4 ,y41 a transf] swit* ( highly insulat$ con/ruction has be5 mu* us$4 ,! two blades ( ?is swit* move indep5d5tly ( ea* o!r1 b bo? are m\nt$ betwe5 ! same metal clips4 ,ea* blade is ( two by "o-qu>t] in* drawn copp] rod1 & ! clips support+ ! two blades are m\nt$ on top ( a circul> metal cap f\r & ?ree-qu>t] in*es 9 outside diamet] & two in*es high1 t is cem5t$ ov] ! top ( a l>ge1 d\ble petticoat1 porcela9 l9e insulator4 ,illu/ration3 ,,fig4 #gi4--;,cross ,section ( ,s*5ectady ,swit*-h\se on ,spi] ,falls ,l9e4 ,clips into :i* ^! copp] blades are swung 9 clos+ ! swit* are also m\nt$ 9 caps c>ri$ by insulators 9 ! way j describ$4 ,ea* ( ^! insulators is m\nt$ on a l>ge wood5 p91 & ^! p9s are secur$ 9 timb]s at ! po9ts :]e ! swit*es are want$4 ,?is con/ruction ( swit*es gives ample insulation = ! l9e voltage ( #cj1jjj 9 ?is sy/em4 ,by means ( ! transf] swit*es j describ$1 ei!r ( ! transmission circuits leav+ ! ,spi] ,falls p[]-plant may be connect$ to any "o ( ! t5 g5]ators & t5 gr\ps ( trans=m]s !re4 ,at ! ,s>atoga swit*-h\se1 any "o ( ! twelve conductors1 mak+ up ! f\r ?ree-phase circuits f ,spi] ,falls may be connect$ to any "o ( ! eighte5 conductors mak+ up ! six ?ree-phase circuits t g s\? to ,s>atoga1 ,wat]vliet1 & ,s*5ectady sub-/ations1 9 ! way indicat$ by ! draw+4 ,s aga9 at ! ,wat]vliet sub-/ation1 :]e en]gy at #bf1ejj volts is receiv$ f ,spi] ,falls & en]gy at #aj1hjj volts f ,me*anicsville1 any s+le conductor f ei!r ( ^! wat]-p[] plants may be connect$1 ei!r directly or ?r\gh a trans=m]1 ) ei!r conductor runn+ to ! railway & light+ sub-/ations ab\t ,albany & ,troy4 ,:]e sev]al transmission circuits are employ$1 ?is complete flexibility ( connection evid5tly adds mat]ially to ! conv5i5ce & reliability ( op]ation4 ,,circuits ,,9 ,,transmission ,,l9es4 ---------------------------------------- ------------------------ ,cycles ,l5g?,numb],numb] ,circul> p] ,location ( ,l9es4 9 ( ( ,mils ,second ,miles4,cir- ,pole p] ( cuits4,l9es4 ,wire4 ,curr5t4 ---------------------------------------- ------------------------ ,electra to ,san ,francisco #adg #a #a ,a#dga1jcd #fj ,colgate to ,oakl&1 ,cal4 #adb #b #b #acc1ajj #fj ,a#baa1jjj ,santa ,ana ,riv] to ,los ,angeles #hc #b #a #hc1fij #fj ,%aw9igan ,falls to ,montreal #he #a #a ,a#ahc1gej #cj ,caon ,f]ry to ,butte #fe #b #b #ajf1ejj #fj ,well& ,canal to ,hamilton #ce #a #a #hc1fij #fj ,well& ,canal to ,hamilton #cg #a #a #acc1ajj #fj ,spi] ,falls to ,s*5ectady #cj #b #a #aje1fjj #dj #afg1hjj ,spi] ,falls to ,wat]vliet1 ,n4 ,y4 #ce #b #a #afg1hjj #dj ,ogd5 to ,salt ,lake ,city #cf #b #a #hc1fij #fj ,apple ,riv] ,falls to ,/4 ,paul #bg #b #a #ff1cgj #fj ,niag>a ,falls to ,buffalo #bc #b #a #cej1jjj #be ,niag>a ,falls to ,buffalo #bj #a #a ,a#ejj1jjj #be ,f>m+ton ,riv] to ,h>t=d #aa #a #a ,a#cfd1dbj #fj ,niag>a ,falls to ,toronto #ge #b #a;,b #aij1jjj #be ---------------------------------------- ------------------------ ,a ,alum9um conductor4 ,b ,/eel t[]s4 ,,*apt] ,,xviii4 ,,pole ,,l9es ,,= ,,p[] ,,transmission4 ,long transmission l9es %\ld foll[ ! mo/ direct r\tes betwe5 g5]at+ & sub-/ations z f> z practicable4 ,! numb] ( poles1 cross-arms1 & insulators increases directly ) ! l5g? ( l9e1 & ! weight ( conductors ) ! squ>e ( t l5g?1 o!r factors rema9+ equal4 ,e mat]ial deviation f a /raight l9e mu/ !re=e be paid = at a r high rate4 ,di/ribution l9es necess>ily foll[ ! public /reets 9 ord] to rea* consum]s1 b ! sav+ ( ! co/ ( a private "r ( way & ease ( access are ! ma9 consid]ations :i* t5d to keep transmission l9es on /reets & highways4 ,except 9 v r\gh or swampy c\ntry1 ! difficulty ( access to a pole l9e on a private "r ( way is n a s]i\s matt] & %\ld be giv5 b little weight4 ,! co/ ( a private "r ( way may be m important1 & %\ld be comp>$ ) ! additional co/ ( ! pole l9e & conductors if erect$ on ! public highway4 ,9 ?is additional co/ %\ld be includ$ any items = pav+ ab\t ! poles1 extra p9s1 insulators1 & guys made necess>y by frequ5t turns 9 ! highway1 & ! sums t may be requir$ to secure ! necess>y fran*ises4 ,!re is also ! possible cont+5cy ( future legislation z to ! voltage t may be ma9ta9$ on wires locat$ ov] public /reets4 ,^! consid]ations tak5 toge!r give a /rong t5d5cy to ! location ( long transmission l9es on private rights ( way1 especially :]e ! am\nt ( p[] involv$ is great & ! voltage v high4 ,a transmission l9e #hj4c miles 9 l5g? rec5tly erect$ betwe5 ,ro*e/] & ,pelham1 ,n4 ,h41 by way ( ,portsm\?1 :]e ! g5]at+ /ation is locat$1 to fe$ an electric railway sy/em1 op]ates at #ac1bjj volts & is ma9ly locat$ on private rights ( way4 ,de$s convey+ ! easem5ts = ?is "r ( way provide t all trees or bran*es )9 "o rod on ei!r side ( ! l9e may be cut away4 ,! transmission l9e betwe5 ,niag>a ,falls & ,buffalo1 ab\t tw5ty-?ree miles long & op]at+ at #bb1jjj volts1 is l>gely on a private way ?irty feet wide4 ,illu/ration3 ,,fig4 #hj4--,transmission ,l9e ( ,new ,hamp%ire ,traction ,company ov] ,hampton ,riv] ,bridge1 #d1fbc ,feet ,long4 ,= ! transmission betwe5 ,caon ,f]ry & ,butte ! l9e is ma9ly locat$ on a private way4 ,betwe5 ,colgate & ,oakl& ! transmission l9e is mo/ly on private way1 & ?is is also true ( ! great] "p ( "s o!r high-pressure l9es 9 ,cali=nia4 ,^! private rights ( way range f fifty to sev]al hundr$ feet wide1 x be+ necess>y 9 =e/s to cut d[n all trees t are tall en\gh to fall onto ! wires4 ,9 "s cases ( transmission at v high voltage two indep5d5t pole l9es are erect$ & "o or m circuits are !n run on ea* set ( poles4 ,?is con/ruction has be5 foll[$ on ! transmission l9e betwe5 ,niag>a ,falls & ,buffalo1 ,caon ,f]ry & ,butte1 ,well& ,canal & ,hamilton1 & betwe5 ,colgate & ,oakl&4 ,su* d\ble pole l9es are m usually locat$ on ! same "r ( way1 ?is be+ true ( ! ,caon ,f]ry & ,colgate sy/ems1 b ?is is n always ! case4 ,9 ! ,hamilton sy/em ! two l9es ( poles1 "o ?irty-five miles & ! o!r ?irty-sev5 miles 9 l5g?1 are locat$ sev]al miles ap>t4 ,! two sets ( poles on a "p ( ! ,buffalo l9e are less ?an ?irty feet1 on ! ,colgate l9e are tw5ty-five feet1 & on ! ,caon ,f]ry l9e are =ty feet ap>t4 ,! ma9 reasons = ! use ( two pole l9es in/ead ( "o are ! probability t an arc />t$ on "o circuit w be communicat$ to ano!r on ! same poles1 & ! great] ease & safety ( repairs :5 ea* circuit is on a sep>ate l9e ( poles4 ,on ea* pole l9e ( ! ,caon ,f]ry transmission1 & also on ea* pole l9e ( ! ,colgate transmission1 !re is only "o ?ree-wire circuit4 ,on ! ,caon ,f]ry l9e ea* wire ( ! two circuits has a cross-section ( only #ajf1ejj circul> mils1 & on ! ,colgate l9e "o circuit is ( #acc1bbe circul> mils wire & ! o!r circuit is ( #baa1fjj circul> mils cable4 ,9 contra/ ) ^! figures ! l9e ( ! ,/&>d ,electric ,company betwe5 ,electra & ,mission ,san ,jos1 a di/ance ( n9ety-n9e miles1 is made up ( only ?ree conductors1 ea* be+ an alum9um cable ( #dga1jcd circul> mils section4 ,inductance increases ) ! frequ5cy ( ! curr5t 9 a conductor1 & 9 ea* ( ! ?ree sy/ems j consid]$ ! frequ5cy is sixty cycles p] second4 ,! use ( "o circuit ( l>g] wire in/ead ( two circuits ( small] wire has ! obvi\s advantage ( great] me*anical /r5g? 9 ea* conductor1 saves ! co/ ( "o pole l9e & ( ! erection ( ! second circuit4 ,) voltages above #dj1jjj to #ej1jjj on long transmission l9es !re is a l>ge loss ( en]gy by leakage directly ?r\gh ! air f wire to wire4 ,to keep ?is loss )9 desirable limits x may be necess>y to give ea* wire ( a circuit a great] di/ance f ! o!rs ( ! same circuit ?an c readily be _h if all ! wires ( ea* circuit are m\nt$ on "o l9e ( poles4 ,if !re is only "o ?ree-wire circuit to be provid$ =1 ?ree l9es ( poles or two l9es ) a long crosspiece betwe5 !m may be set ) any desir$ di/ance betwe5 ! l9es s t ! leakage ?r\gh ! air ) "o wire on ea* pole w be r$uc$ to a small quantity4 ,on a l9e built 9 ?is way x w\ld be practically impossible = an arc to />t betwe5 ! wires by any ( ! usual means4 ,di/ances f pole to pole 9 ! same l9e v>y some:at ) ! numb]1 size1 & mat]ial ( ! conductors to be c>ri$4 ,on ord9>y con/ruction 9 a /raight l9e poles are (t5 spac$ f #ajj to #aaj feet ap>t--t is1 ab\t fifty poles p] mile4 ,on curves & ne> corn]s ! spac+ ( poles %\ld be %ort]4 ,poles = ! #hj4c miles1 m5tion$ 9 ,new ,hamp%ire1 are regul>ly locat$ #ajj feet ap>t4 ,( ! two pole l9es betwe5 ,niag>a ,falls & ,buffalo1 ! old] 0 design$ to c>ry twelve copp] cables ( #cej1jjj circul> mils ea*1 & its poles 7 spac$ only #gj feet ap>t4 ,! new] l9e is design$ to c>ry six alum9um cables ( #ejj1jjj circul> mils ea* & its poles are #adj feet ap>t4 ,poles 9 ea* ( ! l9es betwe5 ,caon ,f]ry & ,butte are regul>ly spac$ #aaj feet ap>t & ea* pole c>ries ?ree copp] cables ( #ajf1ejj circul> mils4 ,illu/ration3 ,,fig4 #ha4--;,*ambly-,montreal ,l9e ,cross+ ! ,*ambly ,canal4 ,illu/ration3 ,,fig4 #hb4--,special ,wood5 ,/ructures on ,l9e ,betwe5 ,spi] ,falls & ,s*5ectady4 ,! two #adb-mile l9es betwe5 ,colgate & ,oakl& are ea* made up ( poles #acb feet ap>t1 & "o l9e ( poles c>ries ! ?ree copp] conductors & ! o!r l9e ( poles ! alum9um conductors already nam$4 ,z alum9um wire has only "o-half ! weight ( copp] wire ( equal conductivity1 ! l5g? ( span betwe5 poles c>ry+ alum9um wire may be great] ?an t :]e copp] is us$4 ,only a "p ( ! /ra9 on poles is due to ! weight ( wires c>ri$1 h[ev]4 ,:]e a body ( wat] mu/ be cross$1 a v long span1 ) special supports = ! wires at ea* side1 may be necess>y4 ,a case ( ?is sort 0 met :]e ! ,colgate & ,oakl& l9e crosses ! ,c>qu9ez ,/raits at a po9t :]e ! wat]way is #c1bjj feet wide4 ,x 0 necess>y to h ! l[e/ "p ( ! cables across ^! /raits at lea/ #bjj feet above ! surface ( ! wat] s t vessels ) ! talle/ ma/s c\ld pass und]nea?4 ,to secure ! necess>y elevation = ! cables a /eel t[] 0 built on ea* bank ( ! /raits at su* a po9t t ! di/ance betwe5 ! po9ts = cable support on ! two t[]s is #d1dbg feet ap>t4 ,z ! banks rise rapidly f ! wat] level1 "o /eel t[] 0 giv5 a height ( only #fe feet1 :ile ! height ( ! o!r 0 made #bbe feet4 ,betwe5 ^! two t[]s f\r /eel cables 7 susp5d$1 ea* cable be+ made up ( n9ete5 /r&s ( galvaniz$ /eel wire1 hav+ an outside diamet] ( sev5-eigh?s in* & weigh+ #g1jhj p\nds = ! span4 ,! break+ /ra9 ( ea* cable is #ih1jjj p\nds1 & x has ! electrical conductivity ( a ,no4 #b copp] wire4 ,! cables are simply support$ on ! t[]s by /eel roll]s1 & ! pull ( ea* cable1 am\nt+ to twelve tons1 is tak5 by an an*orage "s di/ance beh9d ea* t[]1 :]e ! cable t]m9ates4 ,ea* an*orage consi/s ( a l>ge block ( cem5t deeply emb$d$ 9 ! gr\nd1 & ) an*or bolts runn+ ?r\gh x4 ,ea* cable is secur$ to its an*orage ?r\gh a s]ies ( /ra9 insulators1 & ! regul> l9e cables ( copp] & alum9um are connect$ ) ! /eel cables j outside ( ! %elt] built ov] ! /ra9 insulators ( ea* an*or4 ,/eel cables 7 us$ = ! long span across ! /raits because ( ! great t5sile /r5g? t c\ld be _h 9 t metal4 ,?is span is1 no d\bt1 ! longe/ & highe/ t has ev] be5 erect$ = electrical transmission at high voltage4 ,illu/ration3 ,,fig4 #hc4--,special ,/ructure on ,l9e ,betwe5 ,spi] ,falls & ,s*5ectady4 ,x has be5 sugge/$ 9 "o in/ance t /eel t[]s n9ety feet high & #a1jjj feet ap>t be sub/itut$ = pole l9es & ! wires /rung f t[] to t[]4 ,su* con/ruction w\ld increase ! difficulty ( insulation & w\ld co/ m at ! />t ?an a l9e ( wood5 poles4 ,! "q is :e!r a l[] ma9t5ance & depreciation rate = ! /eel t[]s w\ld (fset _! disadvantages comp>$ ) poles4 ,pole l9es %\ld be /ak$ out ) a transit1 & ! same in/rum5t c be us$ to give a p]p5dicul> position to ea* pole & br+ x into l9e4 ,wood5 poles are us$ 9 mo/ cases ( high-voltage transmission l9es4 ,iron poles w\ld make x unsafe to "w on any circuit c>ri$ by !m :5 x 0 transmitt+ curr5t at high voltage4 ,) iron poles a defective insulator might lead to ! de/ruction ( ! conductors at t po9t ?r\gh cont9u\s arc+ on to ! iron4 ,illu/ration3 ,,fig4 #hd4--;,cross+ ( ,delaw>e & ,hudson ,railway ,tracks by #cj1jjj-volt ,l9e at ,s>atoga1 ,n4 ,y4 ,! k9ds ( wood us$ = poles v>y 9 diff]5t sections ( ! c\ntry4 ,9 ,new ,engl&1 *e/nut poles are a favorite & 7 us$ on ! #hj4c miles ( transmission l9e m5tion$ 9 ,new ,hamp%ire4 ,c$> poles are us$ to "s ext5t 9 ne>ly all p>ts ( ! c\ntry1 includ+ ,canada4 ,spruce & p9e poles are employ$ to "s ext5t1 especially 9 l5g?s ( m ?an fifty feet4 ,9 ! ,rocky ,m\nta9 region & 9 ,cali=nia r\nd c$> poles f ! =e/s ( ,oregon1 ,wa%+ton1 & ,idaho are mu* us$4 ,saw$ r$wood poles f ! trunks ( l>ge trees 7 erect$ on ! #adg-mile l9e betwe5 ,electra p[]-h\se & ,san ,francisco4 ,= ! ,colgate & ,oakl& l9e ,oregon c$> poles 7 select$1 & ! transmission betwe5 ,caon ,f]ry & ,butte 0 c>ri$ out ) c$> poles f ,idaho4 ,= transmission circuits x is f> m important at mo/ po9ts to h poles v /rong r ?an v long4 ,:]e wires or ob/ructions mu/ be cross$ by ! high-voltage circuits ! poles %\ld be long en\gh to c>ry ^! circuits well above ev]y?+ else4 ,9 ! op5 c\ntry1 :]e no ob/ructions are to be avoid$1 x does n pay to use poles ) a l5g? great] ?an ?irty-five feet4 ,illu/ration3 ,,fig4 #he4--,pole ,l9e f ,spi] ,falls ov] ,m\nt ,mc,gregor4 ,%ort poles (f] less surface to ! w9d1 ! l5g? ( ! lev] ?r\gh :i* w9d pressure acts to break ! pole at ! gr\nd decreases ) ! l5g? ( pole1 & ! %ort] ! poles ! small] is ! /ra9 on /ruts & guy wires4 ,if poles are only ?irty or ?irty-five feet long1 !y may be l>ge 9 diamet] )\t excessive co/4 ,z a rule1 no pole %\ld be us$ ) a top less ?an sev5 in*es 9 diamet]1 & a pole ) ?is top %\ld n be requir$ to c>ry m ?an ?ree wires4 ,a pole ) sev5- or eight-in* top & ?irty feet long %\ld measure n less ?an twelve in*es 9 diamet] at ! butt4 ,= long] poles ! diamet]s at ! butt %\ld increase up to at lea/ eighte5 in*es = a r\nd pole sixty feet long4 ,9 ! ,new ,hamp%ire transmission above nam$ ! /&>d l5g? ( poles is ?irty-five feet4 ,on ! l9e betwe5 ,caon ,f]ry & ,butte ! poles range f ?irty-five to n9ety feet 9 l5g?4 ,! r\nd c$> poles us$ 9 ! ,colgate & ,oakl& l9e range f tw5ty-five to sixty feet 9 l5g?1 f eight to twelve in*es diamet] at ! top1 & f twelve to eighte5 in*es diamet] at ! butt4 ,on ! l9e betwe5 ,electra & ,san ,francisco ! squ>e-saw$ r$wood poles are report$ to h ! foll[+ dim5sions1 9 a pap] read at ! annual conv5tion ( ,edison ,illum9at+ ,companies 9 #aijb4 --------------------------------------- ,height1 ,top1 ,butt1 ,dep? ,feet4 ,in*es4 ,in*es4 9 ,gr\nd4 --------------------------------------- #ce #g #g #ab #ab #e4e #dj #h #h #ac-a_/b #ac-a_/b #f #de #i #i #ae #ae #f4e #ej #aj #ajaf #af #g #fj #aa #aaag #ag #h --------------------------------------- ,! relative dim5sions ( ^! poles are ( int]e/ because1 be+ saw$ f ! trunks ( l>ge trees1 !y c\ld h any desir$ measurem5ts at ! tops & butts4 ,^! poles1 ov] ! great] "p ( ! l9e1 c>ri$ ! ?ree alum9um cables ( #dga1jcd circul> mils ea*1 previ\sly m5tion$4 ,dep? to :i* poles are set 9 ! gr\nd ranges f ab\t five feet = tw5ty-five- or ?irty-foot poles to eight feet = poles sixty feet long4 ,9 locations :]e ! soil is v s(t or :]e poles mu/ resi/ heavy /ra9s ! /ability ( ea* pole may be mu* increas$ by digg+ ! hole two feet or m l>g] 9 diamet] ?an ! butt ( ! pole1 & !n fill+ 9 cem5t concrete--"o "p1 by measure1 ( ,portl& cem5t1 ?ree ( s& & five ( brok5 /one--all ar\nd ! butt ( ! pole aft] x is 9 ! hole4 ,! butts ( poles up to a po9t "o foot or m above ! gr\nd l9e are frequ5tly treat$ ) hot t>1 pit*1 asphalt1 or c>bol9eum be=e ! poles are erect$1 & 9 ,salt ,lake ,city salt is said to be us$ ar\nd pole butts aft] !y are 9 ! hole4 ,9 "s cases ! poles ( transmission l9es are pa9t$ ov] _! entire l5g?4 ,pole tops %\ld always be po9t$ or w$ge-%ap$1 to %$ wat]1 & pa9t or t> %\ld be appli$ to ^! tops4 ,9 "s cases poles are fill$ ) crude petroleum or o!r pres]vative comp\nd 9 iron retorts1 :]e moi/ure is )drawn f ! pole by exhau/+ ! air1 & !n1 aft] treatm5t ) dry /eam1 ! poles h ! comp\nd =c$ into !m by hydraulic pressure4 ,9 favorable soils c$> poles may rema9 fairly s\nd = tw5ty ye>s1 *e/nut poles m ?an "o-half ( t "t1 & spruce & p9e ab\t five ye>s4 ,poles up to =ty feet 9 l5g? may be readily set ) pike poles1 b :5 !y are mu* long] ?an ?is a d]rick w save "t & labor4 ,a d]rick %\ld h a little m ?an "o-half ! l5g? ( ! poles to be set4 ,illu/ration3 ,,fig4 #hf4--;,*ambly-,montreal ,l9e ,cross+ ! ,ri*elieu ,riv]4 ,poles %\ld be guy$ or brac$ at all po9ts :]e !re are mat]ial *anges 9 ! direction ( ! l9e1 & on long /raight /ret*es ab\t e fif? pole %\ld be guy$ or brac$ 9 bo? directions to prev5t ! poles sett+ back :5 ! l9e wire is cut or brok5 at any po9t4 ,:]e !re is room = wood5 /ruts1 z on a private "r ( way1 !y %\ld be us$ in/ead ( guys because ( _! m sub/antial "* & ! high] security ( insulation ?us obta9$4 ,ord9>y /ra9 insulators _c be reli$ on ) l9es t op]ate at v high voltages1 & :]e guys mu/ be us$ a timb] f\r by six in*es & t5 to tw5ty feet long may h ! guy twi/$ ab\t ea* end ( x & be us$ z a /ra9 insulator4 ,a guy or /rut %\ld come well up "u ! l[] cross-arm on a pole to avoid break+ ( ! pole at ! po9t ( atta*m5t4 ,:]e poles h heavy circuits & sev]al cross-arms ea* x is sometimes desirable to atta* a guy or /rut b5ea? ! l[e/ arm & also a guy close to ! pole top4 ,galvaniz$ iron or /eel wire is ! mat]ial be/ suit$ = guys1 & ! cable =m has great] /r5g? & is m flexible ?an solid wire4 ,illu/ration3 ,,fig4 #hg4--;,cross-arms & ,insulators on ! ,l9e ,betwe5 ! ,*ambly ,plant & ,montreal4 ,on ! transmission l9e betwe5 ,electra & ,san ,francisco1 :i* is int5d$ to op]ate at #fj1jjj volts1 ! use ( guys has be5 mo/ly avoid$ & /ruts employ$ in/ead4 ,:]e a guy _h to be us$1 a /ra9 insulator ( wood six by six in*es & tw5ty feet long 0 ins]t$ 9 x4 ,! numb] & spac+ ( cross-arms on ! poles ( transmission l9es are regulat$ by ! numb] ( circuits t ea* pole mu/ c>ry & by ! desir$ di/ance ap>t ( ! wires4 ,=m]ly x 0 common to c>ry two or m circuits on a s+le l9e ( poles1 b n[ a frequ5t practice is to give ea* pole l9e only "o circuit & ea* pole only "o cross-arm1 except t a small cross-arm = a telephone circuit is plac$ "s feet bel[ ! p[] wires4 ,) only "o transmission circuit p] pole l9e1 "o wire is usually plac$ at ! top ( ! pole & ! o!r two wires at opposite ends ( ! s+le cross-arm4 ,! old] pole l9e = ! transmission betwe5 ,niag>a ,falls & ,buffalo c>ri$ two cross-arms p] pole = ! p[] wires1 ^! cross-arms be+ two feet ap>t4 ,ea* cross-arm 0 ( yell[ p9e1 twelve feet long1 f\r by six in*es 9 section1 & int5d$ to c>ry f\r ?ree-wire circuits1 b only two circuits h be5 erect$ on ^! two cross-arms4 ,on ! lat] pole l9e = ?is same transmission ea* pole c>ries two cross-arms1 ! upp] int5d$ = f\r & ! l[] cross-arm = two wires1 s t "o ?ree-wire circuit may be /rung on ea* side ( ! poles1 two wires on ! upp] & "o on ! l[] arm 9 ! =m ( an equilat]al triangle4 ,! pole l9es betwe5 ,caon ,f]ry & ,butte1 ,colgate & ,oakl&1 & ,electra & ,san ,francisco all h only "o cross-arm = p[] wires p] pole1 & ! ?ird wire ( ! circuit 9 ea* case is m\nt$ at ! top ( ! pole s t ! ?ree conductors are at ! corn]s ( an equilat]al triangle4 ,?is relative position ( ! conductors makes x easy to transpose !m z (t5 z desir$4 ,on ! l9e f ,caon ,f]ry to ,butte ! cross-arms are ea* eight feet long ) two holes = p9s sev5ty-eight in*es ap>t1 & are atta*$ to ! pole five feet t5 & "o-half in*es f ! top4 ,ga9s = cross-arms %\ld be cut f "o to two in*es deep 9 poles be=e !y are rais$1 & "o hole = ?ree-qu>t]s or sev5-eigh?s-in* bolt %\ld be bor$ ?r\gh ! c5tre ( ! cross-arm & ( ! pole at ! ga94 ,ea* cross-arm %\ld be atta*$ to ! pole by a s+le bolt pass+ entirely ?r\gh ! pole & cross-arm ) a wa%] ab\t ?ree in*es 9 diamet] next to ! cross-arm4 ,"o l>ge ?r\gh bolt weak5s ! pole & arm less ?an two small] bolts or lag-screws1 & ! arm c be m easily replac$ if !re is only "o bolt to remove4 ,alt]nate poles 9 a l9e %\ld h _! cross-arms bolt$ on opposite sides1 & at corn]s d\ble arms %\ld be us$4 ,yell[ p9e is a favorite wood = cross-arms1 ?\gh o!r v>ieties are also us$4 ,! l>ge1 long p9s necess>y on high voltage l9es t5d to increase ! sectional area ( cross-arms1 & a section less ?an five & "o-half by f\r & "o-half in*es is seldom desirable4 ,on ! l9e betwe5 ,electra & ,san ,francisco1 :i* c>ries ! ?ree alum9um cables ( #dga1jcd circul> mils ea*1 ! cross-arms ( ,oregon p9e h a section ( six by six in*es ea*4 ,/&>d dim5sions ( "s small] cross-arms are f\r & ?ree-qu>t]s by ?ree & ?ree-qu>t]s in*es1 b x may be d\bt$ :e!r ^! arms are /rong en\gh = long transmission "w4 ,cross-arms %\ld be surfac$ all ov] & cr[n$ "o-qu>t] to "o-half in* on top s z to %$ wat]4 ,aft] be+ kiln dri$1 cross-arms %\ld be boil$ 9 asphaltum or l9se$ oil to pres]ve ! wood & give x high] insulat+ prop]ties4 ,cross-arms long] ?an five feet %\ld be secur$ by braces />t+ at ! pole "s di/ance bel[ ea* arm & ext5d+ to po9ts on ! arm ab\t half-way betwe5 ! pole & ea* end ( ! arm4 ,illu/ration3 ,,fig4 #hh4--,tail ,race & ,pole ,l9e at ,*ambly1 ,quebec ,p[]-/ation4 ,ea* brace may be ( flat b> iron ab\t "o & "o-half by "o-qu>t] in* 9 section1 or ! brace = bo? ends ( an arm may be made ( a s+le piece ( angle-iron b5t into ! prop] %ape4 ,= high-voltage l9es x is undesirable to employ iron braces ( any sort1 s9ce ^! braces =m a pa? ( l[ resi/ance t comes mu* too close to ! p9s on :i* ! insulators & wires are m\nt$4 ,braces =m$ ( h>d wood are mu* bett] z to insulation1 & su* braces ( maple are 9 use on ! l9e betwe5 ,butte & ,caon ,f]ry :]e ! voltage is #ej1jjj4 ,ea* brace on t l9e is ?irty-six in*es long & ?ree in*es wide1 ) "o end bolt$ to ! c5tre ( its pole & ! o!r end to ! cross-arm tw5ty-?ree in*es f ! pole c5tre4 ,! l9e f ,electra has h>d-wood braces secur$ ) wood p9s4 ,wood is ! mo/ common mat]ial = p9s on :i* to m\nt ! insulators ( high-voltage transmission circuits4 ,iron has be5 us$ = p9s to "s ext5t1 & its use is on ! increase4 ,oak & locu/ p9s are g5]ally us$1 ! latt] be+ /rong] & m la/+4 ,9 ,cali=nia1 p9s ( eucalyptus wood are mu* us$ & are said to be /rong] ?an locu/4 ,all wood5 p9s %\ld be boil$ sev]al h\rs 9 l9se$ oil aft] be+ well dri$4 ,?is increases ! insulat+ & la/+ prop]ties ( ! p9s4 ,high-voltage l9es require long p9s to hold ! l[] edges ( insulators well above ! cross-arms1 & ^! p9s mu/ be mu* /rong] ?an ^? us$ on ord9>y l9es1 because ( ! increas$ lev]age ( ea* wire4 ,a p9 twelve in*es long ov] all & hav+ a diamet] ( "o & "o-half in*es 9 ! "p t ent]s ! cross-arm has be5 mu* us$ = transmission circuits1 b is mu* too %ort & weak = high voltages4 ,on ! #ej1jjj-volt l9e betwe5 ,caon ,f]ry & ,butte ! p9s are season$ oak boil$ 9 p>aff94 ,ea* ( ^! p9s is sev5te5 & "o-half in*es long1 two & "o-half in*es 9 diamet] = a l5g? ( f\r & "o-half in*es 9 ! middle "p1 two in*es 9 diamet] = a l5g? ( five & "o-half in*es t fits into ! cross-arm or pole top1 & "o & "o-half in*es 9 diamet] at ! top ( ! ?read inside ( ! insulator4 ,^! p9s hold ! outside edges ( ! insulators n9e in*es above ! tops ( cross-arms4 ,ea* ( ^! p9s is held 9 its socket by a ?ree-eigh?s-in* bolt t passes entirely ?r\gh ! p9 & ! cross-arm or pole top4 ,on ! l9e betwe5 ,electra & ,san ,francisco ! p9s are ea* sixte5 & sev5-eigh?s in*es long1 two & ?ree-qu>t]s in*es 9 diamet] at ! l>ge/ c5tral "p1 & two & "o-qu>t] in*es 9 diamet] 9 ! l[] "p1 five in*es long1 t fits into ! cross-arm or pole top4 ,"o ( ^! p9s broke at ! %\ld] ) a pull ( #b1bjj p\nds at ! ?read$ "p4 ,c>riage bolts "o-half in* 9 diamet] pass ?r\gh ! cross-arm & p9 two in*es f ! top ( ! arm1 & "o bolt ?ree in*es f ! p9 on ea* side4 ,)\t ^! bolts ! arms split on te/ ) a pull ( #a1bjj p\nds on ! p91 b ) ! bolts ! p9 broke z above4 ,,*apt] ,,xix4 ,,entries ,,= ,,electric ,,transmission ,,l9es4 ,! entrance ( transmission l9es into g5]at+ plants & sub-/ations pres5ts special problems 9 con/ruction & insulation4 ,"o ( ^! problems has to d ) ! me*anical security ( ea* conductor at ! po9t :]e x passes ?r\gh ! side or ro( ( ! /ation4 ,conductors are sometimes atta*$ to ! /ation s t ! /ra9 ( ! l9e is borne by ! side wall :]e !y ent] & t5ds to pull x out ( l9e4 ,?is practice has b little to comm5d x1 aside f conv5i5ce1 = unless ! conductors are r small1 or ! wall ( ! /ation is unusually heavy1 ! pull ( ! =m] is apt to bulge ! latt] 9 ! c\rse ( "t4 ,= any heavy l9e ! end /ra9 is ultimately mo/ suitably tak5 by an an*or securely fix$4 ,z special insulators mu/ be us$ :]e a conductor is secur$ directly to su* an an*or1 x is usually m conv5i5t to set "o or m heavy poles ) d\ble cross-arms at ! end ( a l9e1 & !n to make ^! poles secure by l>ge /ruts1 or by guys atta*$ to an*ors4 ,extra heavy cross-arms on ^! end poles %\ld be provid$ ) iron p9s = ! l9e insulators2 two or m ( ! insulators m\nt$ 9 ?is way )9 a few feet ( ea* o!r1 = ea* wire1 w /& up aga9/ ! end /ra9 on almo/ any l9e4 ,insulators t are to take ! end /ra9 ( a l9e 9 ?is way %\ld all[ atta*m5t ( ! wire at ! side1 s t ! =ce ex]t$ by ea* conductor t5ds to press ! insulator aga9/ ! side ( its p91 r ?an to pull (f ! top ( ! insulator4 ,! end /ra9 ( ! l9e hav+ be5 tak5 on poles close to ! /ation1 ! conductors may be atta*$ to insulators on ! wall1 ! latt] ?us be+ subject$ to v little me*anical /ra94 ,ov]head l9es usually ent] a /ation ?r\gh "o ( its side walls1 b an entry may be made 9 ! ro(4 ,x is desirable to h a side entry on ! gable end ( a build+ r ?an on a side bel[ ! eaves :]e !re w be mu* dripp+ ( wat]4 ,if an entry mu/ be made bel[ ! eaves1 a %elt] %\ld be provid$ above ! entry1 & ! ro( ( ?is %elt] %\ld h a gutt] t w c>ry wat] away f ! wires4 ,entrance ( ea* conductor into a /ation mu/ be effect$ 9 su* a way t ample insulation ( ! circuit w be ma9ta9$1 & 9 "s cases s t ra91 sn[1 & w9d w be exclud$4 ,! l9e voltage & ! climate :]e ! /ation is locat$ ?us h an important be>+ on ! =m ( entry t is suitable 9 any p>ticul> case4 ,! simple/ =m ( entry = a high-voltage l9e is a cle> op5+1 usually circul> 9 =m1 ?r\gh ! wall ( ! /ation = ea* wire4 ,insulators = ea* wire %\ld be provid$ bo? inside & outside ( ! wall to hold ! wire at ! c5tre ( ?is op5+4 ,su* insulators are usually mo/ conv5i5tly support$ by fixtures atta*$ to bo? sides ( ! wall1 & insulators on ! outside %\ld ( c\rse be kept 9 an upright position1 unless completely protect$ f ra9 & sn[4 ,! diamet] ( ! op5+s ?r\gh ! wall %\ld be great en\gh to prev5t any visible dis*>ge ( curr5t betwe5 ! wire & wall "u ! wor/ conditions ( sn[1 ra91 fog1 or du/4 ,su* an op5+ mu/1 !re=e1 increase 9 diamet] ) ! voltage ( ! l9e4 ,! l>g] ^! op5+s = ! l9e wires1 ! great] is ! opportunity = ra91 sn[1 du/1 & cold air to ent] ! /ation ?r\gh !m4 ,op5+s may be s protect$ z to keep out sn[ & ra9 by means ( %elt]s on ! outside ( ! wall on :i* !y are plac$1 b su* %elt]s _c keep out ! cold air4 ,if ! op5+s = ! entrance ( wires are locat$ 9 ! wall ( a room t conta9s air-bla/ trans=m]s1 ! area ( op5+s = circuits ( v high voltage may be no great] ?an is necess>y to all[ ! escape ( heat$ air f ! trans=m]s4 ,! mild] ! climate1 o!r factors be+ ! same1 ! high] ! voltage ( circuits :i* may ent] a /ation ?r\gh op5+s t are free = ! movem5t ( air4 ,) circuits ( only mod]ate voltage1 say less ?an #ae1jjj1 x is q practicable to admit wires to a /ation ?r\gh p]fectly free op5+s1 9 ! colde/ p>ts ( ! ,unit$ ,/ates4 ,) voltages ( #bj1jjj to #fj1jjj x is (t5 necess>y1 9 ! cold] p>ts ( ! c\ntry1 to close ! op5+ 9 ! wall ?r\gh :i* ea* wire ent]s ) a disc ( insulat+ mat]ial4 ,9 ord] to keep ! curr5t leakage ov] ^! discs )9 prop] limits1 ! diamet]s ( ! discs mu/ increase ) ! voltage ( ! circuit4 ,?is increase ( disc diamet] obvi\sly l5g!ns ! pa? ( leakage curr5t ov] ! disc surface4 ,:]e ! op5+s 9 a wall = ! entrance ( high-voltage circuits are clos$ by insulat+ discs ab\t ! wires1 ^! discs may make actual contact ) b>e wires1 or ! wire at ea* entry may h "s special insulation4 ,9 ! side wall ( ! sub-/ation at ,man*e/]1 ,n4 ,h41 ! entrance ( transmission l9es f f\r wat]-p[] plants is provid$ = by circul> op5+s 9 slate slabs t are built into ! brickwork4 ,! transmission circuits f ?ree ( ! wat]-p[] plants op]ate at #aj1jjj to #ab1jjj volts1 & ! circuit f ! f\r? plant at ab\t #f1jjj volts4 ,circul> op5+s 9 ! slate slabs are ea* five in*es 9 diamet]1 & !y are spac$ twelve to fifte5 in*es betwe5 c5tres4 ,a s+le wire ent]s ?r\gh ea* ( ^! op5+s & is held at ! c5tre by insulators bo? inside & outside ( ! wall4 ,ea* wire is b>e :]e x passes ?r\gh ! slate slab1 & ! circul> op5+s are n clos$ 9 any way4 ,! l>ge/ wires pass+ ?r\gh ^! five-in* circul> op5+s 9 ! slate slabs are ( solid copp]1 ,no4 #j1 ( #j4cbe-;in* diamet] ea*4 ,be=e pass+ ?r\gh ! op5+ 9 ! slate slabs ! wires ( ^! transmission circuits are ti$ to regul> l9e insulators support$ by cross-arms secur$ to ! outside ( ! brick wall by iron brackets4 ,! po9t ( atta*m5t ( ea* wire to its insulator is ab\t n9e in*es bel[ ! c5tre ( ! circul> hole by :i* x ent]s ! sub-/ation4 ,?is ,man*e/] sub-/ation is equipp$ ) air-bla/ trans=m]s f :i* ! hot air is dis*>g$ into ! same room t ! transmission l9es ent]4 ,along "o side ( ! sub-/ation !re are tw5ty-sev5 ( ^! five-in* circul> op5+s 9 ! slate slabs = entrance ( ! high-voltage l9es1 & on ano!r side ( ! sub-/ation !re are a great] numb] ( small] op5+s = ! di/ribution circuits4 ,7 x n = ! air-bla/ trans=m]s1 all ( ^! op5+s w\ld probably admit m air ?an w\ld be desirable 9 a climate z cold z t at ,man*e/]4 ,ano!r example ( op5+s 9 ! walls ( a /ation = ! entrance ( transmission circuits1 :]e !re is free movem5t ( ! air betwe5 ! inside & outside ( ! build+1 is t ( ! #cc1jjj-volt l9e betwe5 ,santa ,ana ,riv] & ,los ,angeles1 ,cal4 ,9 ?is case a sew] pipe twelve in*es 9 diamet] is built into ! wall ( ! /ation = ea* wire ( ! l9e1 s t !re is a free op5+ ( ?is size f inside to outside4 ,ea* wire ( ! #cc1jjj-volt circuit ent]s ! /ation ?r\gh ! c5tre ( "o ( ^! twelve-in* pipes1 & is ?us surr\nd$ by six in*es ( air on e side4 ,z ! temp]ature ne> ,los ,angeles seldom or nev] goes d[n to z]o1 ^! l>ge op5+s d n admit en\gh air to be objectionable4 ,besides ?is mild climate1 air-bla/ trans=m]s add to ! favorable features 9 ! /ations hav+ ! twelve-in* op5+s4 ,9 ano!r case1 h[ev]1 :]e ! op5+s = ! entrance ( wires ( v high voltage all[ free movem5t ( air betwe5 ! inside & outside ( ! /ation1 ! climate is cold & ! w9t] temp]atures g d[n to #cj or m bel[ z]o4 ,?is condition exi/s on ! #be1jjj-volt l9e betwe5 ,apple ,riv] ,falls & ,/4 ,paul1 :]e six ,no4 #b wires ent] ! g5]at+ /ation ?r\gh pla9 circul> op5+s 9 ! brick side wall ( a small ext5sion :]e ! lightn+ arre/]s are locat$4 ,air-bla/ trans=m]s are locat$ 9 ! end ( ! /ation next to ?is lightn+-arre/] h\se1 b x is n c]ta9 t ! hot air f !m escapes ?r\gh ! op5+s = ! wires4 ,9 ano!r case :]e ! climate is ab\t z cold z t j nam$1 a gall]y is built along "o side ( ! ext]ior ( ! /ation at "s di/ance above ! gr\nd1 & two op5+s are provid$ = ea* wire ( ! high-t5sion l9e4 ,"o ( ^! two op5+s is 9 ! horizontal floor ( ! gall]y & all[s ! entrance ( ! wire f ! outside1 & ! o!r op5+ is 9 ! side wall ( ! /ation aga9/ :i* ! gall]y is built4 ,! two op5+s = ea* wire be+ ?us at "r angles to ea* o!r1 & ! op5+ to ! outside air be+ protect$ f ! w9d by its horizontal position1 no m ?an a p]missible am\nt ( cold air1 x is said1 f9ds its way into ! /ation4 ,9 "s cases ) l9es ( mod]ate voltage1 say #aj1jjj to #ae1jjj1 & 9 probably ! majority ( cases ) l9es ( #be1jjj volts or m1 ! entry = ! high-t5sion wires is entirely clos$4 ,an example ( ?is practice may be se5 at ! v>i\s sub-/ations ( ! ,new ,hamp%ire ,traction ,company1 :i* are locat$ along _! #ab1jjj-volt l9e betwe5 ,portsm\? & ,pelham1 9 t ,/ate4 ,= ! entry ( ea* wire on ^! l9es a sixte5-in* squ>e op5+ is made 9 ! brick wall ( ! sub-/ation4 ,on ! outside ( ?is wall a box is built ab\t a gr\p ( ?ree or m ( ^! op5+s locat$ side by side4 ,! top or ro( ( ?is box is =m$ by a slab ( blue/one ?ree in*es ?ick1 :i* is set into ! wall & ext5ds tw5ty-six in*es f ! face ( ! wall1 ) a slight slope f ! horizontal4 ,! ends1 ! bottom1 & ! out] side ( ?is box are =m$ by slabs ( slate "o in* ?ick1 s t ! enclos$ space has an area 9 v]tical cross section at "r angles to ?is build+ #ae4e in*es high & tw5ty-two in*es wide4 ,illu/ration3 ,,fig4 #hi4--;,cable ,ent]+ ,build+4 ,9 ! bottom ( ?is box !re is a circul> op5+ = ea* wire1 & into ?is op5+ fits a heavy glass or porcela9 bu%+ ?r\gh :i* ! wire passes4 ,aft] rea*+ ! inside ( ! box ! wire turns at "r angles & passes ?r\gh ! sixte5-in* squ>e op5+ into ! sub-/ation4 ,b5ea? ! box a special insulator is secur$ by an iron bracket to ! outside ( ! brick wall = ea* l9e wire1 & ?is insulator takes ! /ra9 ( ! wire be=e x is c>ri$ up ?r\gh ! bu%+ 9 ! bottom ( ! box4 ,?is =m ( entry is p]missible :]e ! desire is to exclude cold air f ! /ation1 & :]e ! voltage is n high en\gh to cause s]i\s leakage ov] ! surface ( ! bu%+ & ! slate =m+ ! bottom ( ! box4 ,9 all ( ! cases above m5tion$ ! wires us$ to ent] ! /ations 7 ! regul> l9e conductors & 7 b>e4 ,ano!r type ( entry 9 sub-/ations is t employ$ on ! ext5sive transmission sy/em betwe5 ,spi] ,falls1 ,s*5ectady1 & ,albany1 ,n4 ,y4 ,! maximum voltage on ?is sy/em is #cj1jjj1 & ! l9es usually ent] ea* sub-/ation ?r\gh ! brick wall at "o ( its gable ends4 ,outside ( & ab\t ! entry ( ea* circuit or gr\p ( circuits a wood5 %elt] is built on ! brick wall ( ! sub-/ation4 ,ea* %elt] has a slant+ ro( t />ts f ! brick wall at "s di/ance above ! op5+s = ! entrance ( ! l9e1 & t]m9ates 9 a gutt]4 ,! front ( ea* %elt] is c>ri$ d[n ?ree feet bel[ ! c5tre ( ! op5+s 9 ! brick wall1 & ! ends g /ill l[]4 ,! front ( ea* %elt] is f\r feet 9 height1 is f\r feet f ! face ( ! brick wall1 & has a circul> op5+ ( #aj-;in* diamet] = ea* wire ( ! transmission l9e4 ,9 l9e ) ea* circul> op5+ 9 ! wood5 %ield !re is an op5+ ( #ae-;in* diamet] 9 ! brick wall ( ! sub-/ation1 & into ?is op5+ 9 ! brickwork fits a r+ ( wood ) #ae-;in* outside & #aa-;in* inside diamet]4 ,to ?is wood5 r+ a #ae-;in* disc ( h>d fibre #a_/h-;in* ?ick is secur$1 & a porcela9 tube #bd in*es long & ( #b-;in* inside diamet] passes ?r\gh a hole 9 ! c5tre ( ?is disc4 ,)9 ! wood5 %ield & 9 l9e ) ea* circul> op5+ 9 x & ) ! correspond+ porcela9 tube ?r\gh ! fibre disc a l9e insulator is secur$4 ,)9 ! sub-/ation & 9 l9e ) ea* tube !re is also an insulator1 & ! two insulators ne> opposite ends ( ea* tube hold ! l9e wire t passes ?r\gh x 9 position4 ,ea* wire ( ! transmission l9es1 ( :i* ! l>ge/ is ,no4 #jjj solid ( #j4daj-;in* diamet]1 t]m9ates at "o ( ! insulators )9 ! wood5 %ield1 & is !re connect$ to a special insulat$ wire t passes ?r\gh "o ( ! porcela9 tubes into ! sub-/ation4 ,a copp] trolley sleeve #ab in*es long is us$ to make ! sold]$ connection betwe5 ! b>e l9e wire & ! insulat$ conductor t passes ?r\gh ! porcela9 tube4 ,ea* ( ^! entry cables1 :atev] its size1 is insulat$ fir/ ) a lay] ( rubb] #i_/cb-;in* ?ick1 !n ) v>ni%$ cambric w\nd on to a ?ickness ( #i_/cb-;in*1 & la/ly ) two lay]s ( wea!r-pro( braid outside ( ! cambric4 ,?is =m ( clos$ entry = ! transmission l9es obvi\sly excludes sn[1 ra91 cold air1 & du/ f ! /ation4 ,:e!r ! fibre discs & wood5 r+s1 toge!r ) ! insulation on ! entry cables1 are z desirable z a glass disc at ! entry is ano!r "q4 ,ano!r in/ance :]e ! entry = a high-t5sion l9e is clos$ ) ! aid ( combu/ible mat]ial is t ( ! #be1jjj-volt transmission betwe5 ! wat]-p[] plant at ,*ambly1 on ! ,ri*elieu ,riv]1 & ! sub-/ation 9 ,montreal4 ,! f\r ?ree-phase circuits ( ?is l9e are made up ( ,no4 #jj wires ( #j4cfe-;in* diamet] ea*1 :i* ent] ! p[]-/ation at ,*ambly & ! t]m9al-h\se 9 ,montreal b>e1 z !y are outside4 ,at ea* end ( ! l9e ! wires are secur$ to insulators on a horizontal arm ) _! c5tres tw5ty-two in*es outside ( an end wall ( ! /ation or t]m9al build+4 ,! insulators are m\nt$ ) _! c5tres ?irty in*es ap>t1 & a few in*es above ! tops ( ^! insulators a correspond+ r[ ( wood5 bu%+s pass ?r\gh ! wall ) an outw>d slant4 ,at ! ,*ambly end ( ! l9e ea* ( ^! bu%+s is ( oak1 boil$ 9 /e>91 f\r in*es 9 diamet] & twelve in*es long4 ,at ! ,montreal end ! wall bu%+s are ( boxwood1 & ea* is f\r in*es squ>e & twelve in*es long4 ,ea* ( ! wood5 bu%+s c>ries a glass tube1 & is itself held 9 position by ! concrete ( ! wall 9 :i* x is locat$4 ,entrance to ! /ation by ea* ( ! b>e ,no4 #jj wires is ga9$ ?r\gh "o ( ^! glass tubes1 & cold air is exclud$4 ,q a diff]5t type ( clos$ entry = ! wires ( a transmission l9e is 9 use on t betwe5 ,%aw9igan ,falls & ,montreal1 :i* op]ates at #ej1jjj volts4 ,= ! entry ( ea* ( ! ?ree alum9um cables t make up ?is l9e1 ea* cable be+ compos$ ( sev5 ,no4 #f ,b4 ,s4 gauge wires1 a tile pipe ( tw5ty-f\r-in*es diamet] 0 set into ! /ation wall4 ,! end ( ea* tile pipe is clos$ by a glass plate1 ) a small hole at its c5tre1 ?r\gh :i* ! cable passes4 ,z ! cable is ?us held twelve in*es f ! t]ra cotta pipe all ! way ar\nd1 any leakage ( curr5t mu/ pass ov] ?is l5g? ( glass surface at ea* cable or ?r\gh ! air4 ,a heavy coat+ ( fro/ sometimes collects on ^! plates1 & ?is increases ! am\nt ( curr5t leakage ov] !m4 ,surface leakage 9 a case ( ?is sort1 ( c\rse1 v>ies ) ! size ( ! glass plate1 & if a tile pipe is us$ ! limit ( size is soon rea*$4 ,!re seems to be no good reason1 h[ev]1 :y a glass plate ( any desir$ dim5sions %\ld n be set directly into ! brick wall ( a /ation = ea* l9e wire & ! tile pipes entirely omitt$4 ,?is plan is foll[$ on ! sy/em ( ! ,utah ,light ,p[] ,company1 :i* ext5ds to ,salt ,lake ,city1 ,ogd51 ,provo1 & a numb] ( o!r po9ts 9 t ,/ate4 ,on ! #dj1jjj-volt l9e ( t sy/em an entry = ea* wire is provid$ by sett+ two plates ( glass into ! brick wall1 "o plate be+ flu% ) ! inn] surface & ! o!r ) ! out] surface ( ! wall4 ,9 ! c5tre ( ea* plate !re is a hole ( ab\t #b4e-;in* diamet]1 into :i* a glass or porcela9 tube fits4 ,! l9e wire ent]s ! /ation ?r\gh ?is tube1 & x does n appe> t any %elt] = ! glass plates is locat$ outside ( ! build+4 ,an entry ( ?is type = ! #dj1jjj-volt l9e ) glass plates 9 a brick wall at a gable end ( ! ,murphy mill is said to h giv5 satisfactory results dur+ f\r ye>s1 ?\gh t wall faces ! s\?we/1 f :i* direction mo/ ( ! /orms come4 ,at ?is entry ea* glass plate is n m ?an eighte5 in*es 9 diamet]1 & ! wires are ab\t f\r feet ap>t4 ,on a #af1jjj-volt l9e ( ! same company1 a glass plate twelve in*es squ>e ) a ?ree-qu>t]-in* hole at its c5tre1 & ! b>e wire pass+ ?r\gh )\t a tube1 has giv5 results t 7 entirely satisfactory4 ,two q diff]5t types ( entry to /ations are us$ on ! #ej1jjj-volt l9e betwe5 ,caon ,f]ry & ,butte1 ,mont4 ,"o type1 employ$ at ! side wall ( a corrugat$ iron build+1 consi/s ( a ?ick bu%+ ( p>aff9$ wood c>ry+ a glass tube two in*es 9 diamet]1 f\r feet long1 ) a side wall ( five-eigh?s to ?ree-qu>t]-in*1 ?r\gh :i* ! l9e conductor passes4 ,on ! ro( ( ! p[]-/ation at ,caon ,f]ry a v]tical entry is made ) ! #ej1jjj-volt circuit4 ,= ?is purpose ea* l9e wire is br\ght to a dead end on ?ree insulators c>ri$ by a timb] fixture on ! ro(4 ,a v]tical tap drops f ea* l9e wire & passes ?r\gh ! ro( & into ! /ation4 ,?is ro( is ( wood1 cov]$ ) t9 outside & l9$ ) asbe/os inside4 ,ea* tap is an insulat$ wire1 & elaborate me?ods are adopt$ 9 ! way ( fur!r insulation1 & to prev5t wat] f foll[+ ! wire d[n ?r\gh ! ro(4 ,ov] ! po9t ( entrance sits a l>ge block ( p>aff9$ wood ) a c5tral hole1 & d[n ?r\gh ?is hole passes a long cyl9d] ( pap] t ext5ds "s di/ance above ! block4 ,into ! top end ( ?is cyl9d] fits a wood bu%+1 & a l5g? ( ! tap wire t has be5 s]v$ ) a ?ick lay] ( rubb] is tightly enclos$ by ?is bu%+4 ,! rubb]-cov]$ portion ( ! tap wire also ext5ds above ! bu%+1 & has tap$ to x a pap] cone t comes d[n ov] ! top ( ! pap] cyl9d] to keep out ! wat]4 ,on ! outside ( ?is pap] cyl9d]1 at a l[] po9t1 a /ill l>g] pap] cone is atta*$ to prev5t wat] f foll[+ ! cyl9d] d[n ?r\gh ! wood5 block4 ,at ! l[] end ( ! pap] cyl9d]1 )9 ! /ation1 !re is ano!r bu%+ ( wood1 & betwe5 ?is & ! wood5 bu%+ at ! top ( ! cyl9d] & inside ( ! pap] cyl9d] !re is a long glass tube4 ,d[n ?r\gh ?is tube & into ! /ation ! insulat$ tap wire passes4 ,f ! exp]i5ce ?us f> ga9$ ) high-voltage l9es1 x seems t _! entrance into /ations %\ld always be at a side wall1 unless !re is "s imp]ative reason = com+ d[n ?r\gh ! ro(4 ,if climatic conditions p]mit1 no =m ( entry c be m reliable ?an a pla91 ample op5+ ?r\gh ! wall ) a l>ge air-space ab\t ea* wire4 ,if ! op5+ mu/ be clos$1 x _h bett] be done ) "o or m l>ge plates ( ?ick glass set directly into ! brickwork ( ! wall4 ,"s additional insulation is obta9$ by plac+ a long glass or porcela9 tube ov] ea* wire :]e x passes ?r\gh ! c5tral hole 9 ! glass plates4 ,ea* conductor %\ld be b>e at ! entry1 z x is on ! l9e4 ,"s ( ! above examples ( exi/+ practice 9 entries = transmission l9es are tak5 f ,vol4 xxii41 ,a4 ,i4 ,e4 ,e4 ,,*apt] ,,xx4 ,,insulator ,,p9s4 ,wood5 insulator p9s are among ! weake/ elem5ts 9 electric transmission sy/ems4 ,z l9e voltages h gone up x has be5 necess>y to increase ! di/ances betwe5 ! outside petticoats ( insulators & _! cross-arms & to l5g!n ! insulators !mselves 9 ord] to keep ! leakage ( curr5t betwe5 ! conductors )9 p]missible limits4 ,to r$uce ! leakage1 ! wires on mo/ l9es are locat$ at ! tops in/ead ( 9 ! old position at ! sides ( _! insulators4 ,all ?is has t5d$ to a l>ge increase ( ! me*anical /ra9s t op]ate to break insulator p9s at ! po9t :]e !y ent] ! cross-arm1 because ! /ra9 on ea* l9e wire acts ) a long] lev]age4 ,aga91 x is sometimes necess>y t transmission l9es make long spans across riv]s or else:]e1 & a v unusual /ra9 may be put on ! insulator p9s at ^! places4 ,z long z ea* electric sy/em 0 conf9$ to a s+le city or t[n a brok5 insulator p9 c\ld be quickly replac$1 & any mat]ial int]ruption ( s]vice f su* a cause 0 improbable4 ,:]e ! light & p[] supply ( a city1 h[ev]1 dep5ds on a long transmission l9e1 z is n[ ! case 9 _m in/ances1 & :]e ! l9e voltage is s great t contact betwe5 a wire & a cross-arm w result 9 ! spe$y de/ruction ( ! latt] by burn+1 a brok5 p9 may easily lead to a s]i\s int]ruption ( ! s]vice4 ,besides ! increase ( me*anical /ra9s on insulator p9s1 !re is ! dang] ( de/ruction ( wood5 p9s by *>r+1 burn+1 & o!r =ms ( dis9tegration due to leakage ( curr5t ov] ! insulators4 ,?is dang] 0 entirely abs5t 9 ! great majority ( cases s long z l9es 7 local & op]at$ at only mod]ate voltages4 ,^! sev]al factors comb9$ are br++ ab\t m>k$ *anges 9 design4 ,on /raight portions ( a transmission l9e ! insulator p9s are subject to /ra9s ( two pr9cipal k9ds4 ,"o ( ^! is due directly to ! weight ( ! insulators & l9e wire1 & acts v]tically to cru% ! p9s by =c+ !m d[n onto ! cross-arm4 ,! o!r is due to ! horizontal pull ( ! l9e wire1 :i* is (t5 mu* increas$ by coat+s ( ice & by w9d pressure1 t5d+ to break ! p9s by b5d+--mo/ frequ5tly at ! po9t :]e !y ent] ! cross-arm4 ,a /ra9 ( m9or importance on p9s is t enc\nt]$ :]e a %ort pole has be5 set betwe5 two high] ones1 & ! l9e at ! %ort pole t5ds to lift ea* insulator f its p91 & ea* p9 f ! cross-arm4 ,:]e ! l9e *anges its direction1 z on curves & at corn]s1 ! side /ra9 on p9s is greatly increas$1 & su* places give by f> ! l>ge/ am\nt ( tr\ble ?r\gh ! break+ ( p9s4 ,! latt] seldom fail by cru%+ ?r\gh ! weight ( ! l9es !y support1 because ! size ( p9 necess>y to )/& ! b5d+ /ra9 has a l>ge factor ( safety z to cru%+ /r5g?4 ,insulators are sometimes lift$ f wood5 p9s1 & ! ?reads ( ^! p9s /ripp$ :]e a %ort pole is us$1 z already not$2 b failure ( ?is k9d is n common4 ,iron p9s are ei!r screw$ or cem5t$ into _! insulators1 b ! cem5t$ jo9t is mu* m desirable1 because :]e a screw jo9t is made ! unequal expansion ( ! iron & ! glass or porcela9 is apt to result 9 breakage ( ! insulator4 ,:]e cem5t is us$1 bo? ! p9s & insulators %\ld be ?read$ or provid$ ) %\ld]s ( "s sort1 s t1 al?\gh ! %\ld]s ( ?reads d n come into contact ) ea* o!r1 !y w1 nev]!less1 help to secure a bett] hold4 ,pure ,portl& cem5t1 mix$ ) wat] to a ?ick liquid1 has be5 us$ ) success1 ! insulator be+ plac$ upside d[n & ! p9 held 9 a c5tral position 9 ! hole ( ! insulator :ile ! cem5t is p\r$ 94 ,ano!r cem5t t has be5 us$ = ! same purpose is a mixture ( li?>ge & glyc]94 ,melt$ sulphur is also available4 ,! same =ces t t5d to lift an insulator f its p9 t5d also to pull ! p9 f its socket 9 ! cross-arm or pole top4 ,) wood5 p9s ! "t-honor$ cu/om has be5 to drive a nail into ! side ( ! cross-arm s t x ent]s ! %ank ( ! p9 9 its socket4 ,?is plan is good en\gh s f> z imm$iate me*anical /r5g? is conc]n$1 b is n desirable1 because x is h>d to remove a nail :5 a p9 is to be remov$1 & also because ! ru/ ( ! nail rots ! wood4 ,a bett] plan is to h a small hole entirely ?r\gh ea* cross-arm & insulator p9 at "r angles to ! %ank ( t p9 9 its socket1 & !n to drive a small wood5 p9 entirely ?r\gh f side to side4 ,"s ( ! important factors affect+ ! /ra9s on insulator p9s v>y mu* on diff]5t transmission l9es1 z may be se5 f ! foll[+ table ( l9es on :i* wood5 p9s are us$4 ,on ! old] l9e betwe5 ,niag>a ,falls & ,buffalo1 ! regul> l5g? ( span is #gj feet1 & ea* copp] conductor ( #cej1jjj circul> mils is atta*$ to its insulator #g4e in*es above ! cross-arm4 ,on ! new l9e ! l5g? ( span is #adj feet1 & ea* alum9um conductor ( #ejj1jjj circul> mils is atta*$ to its insulator #aj in*es above ! cross-arm4 ,,table ,i4--,,data ,,( ,,l9es ,,on ,,wood5 ,,p9s4 ---------------------------------------- ------------------------- ,circul> ,mils,feet ,l5g? ,in*es f ,location ( ! ,l9es4 ( ,ea* ( ,span ,wire to ,conductor4 ,betwe5 ,%ank ( ,p94 ,poles4 ---------------------------------------- ------------------------- ,colgate to ,oakl& ,b#acc1ajj 444 #ac ,electra to ,san ,francisco ,a#dga1jcd #acj #ae ,caon ,f]ry to ,butte ,b#aje1fjj #aaj #ac-a_/b ,%aw9igan ,falls to ,montreal ,a#ahc1gej #ajj #af-a_/d ,niag>a ,falls to ,buffalo ,b#cej1jjj #gj #g-a_/b ,niag>a ,falls to ,buffalo ,a#ejj1jjj #adj #aj ,*ambly to ,montreal ,b#acc1ajj #ij #h-a_/b ,colgate to ,oakl& ,a#baa1fjj 444 #ac ---------------------------------------- ------------------------- ,a ,alum9um conductors4 ,b ,copp] conductors4 ,,table ,,ii4--,,dim5sions ,,( ,,wood5 ,,p9s ,,9 ,,in*es4 ---------------------------------------- ----------------------- ,l5g?,l5g?,diam- ,diam-,diamet] ,l5g? ,location ( ,l9es4 ( ( et] et] ( ( ,/em4 ,%ank4 ( ( ,?read$,?read$ ,%ank4,%\l- ,end4 ,"p4 d]4 ---------------------------------------- ----------------------- ,colgate to ,oakl& #aj-c_/h #e-c_/h #b-a_/h #b-a_/b #a-c_/h #b ,electra to ,san ,francisco #ab #d-g_/h #b-a_/d #b-c_/d #a-c_/h #b ,caon ,f]ry to ,butte #ab-a_/b #e-a_/h #b #b-a_/b #a-a_/h #c ,%aw9igan ,falls to ,montreal #ac-a_/b #e #b-c_/d #c #a 44 ,niag>a ,falls to ,buffalo,a #e-a_/d #f #b #b-c_/d #g_/h #a-a_/b ,niag>a ,falls to ,buffalo,b #g-c_/d #f #b-a_/d #b-c_/d #a-a_/b #b-a_/b ,*ambly to ,montreal,c #g #e #a-a_/b #a-g_/h 44 44 ,caon ,f]ry to ,butte,d#ab-c_/h #g-g_/h #b-a_/h #b-a_/b #a-a_/h #c ---------------------------------------- ----------------------- ,a ,p9s on old l9e4 ,b ,p9s on new l9e4 ,c ,approximate dim5sions4 ,d ,pole top p9s4 ,to comp5sate = ! great] /ra9s introduc$ by d\bl+ ! l5g? ( span & us+ p9s ( long] /em1 ! diamet] ( ! %ank ( ! new p9s 0 increas$ to two in*es4 ,"o l9e betwe5 ,colgate & ,oakl& is ( copp]1 & ! o!r is ( alum9um conductors1 b ! same p9s appe> to be us$ = ea*4 ,on ! l9e betwe5 ,caon ,f]ry & ,butte1 ,mont41 ! p9 us$ 9 pole tops has a %ank #b-c_/d in*es long] & #a_/h-;in* great] 9 diamet] ?an ! p9 us$ 9 cross-arms4 ,! weake/ p9 includ$ 9 ! table seems to be t 9 use on ! l9e betwe5 ,*ambly & ,montreal1 :i* is ( hickory wood1 ab\t #a-a_/b in*es 9 diamet] at ! %ank1 & c>ries its ,no4 #jj copp] wire #h-a_/b in*es above ! cross-arm4 ,! foll[+ dim5sions = /&>d wood5 insulator p9s to be us$ on all transmission l9es are propos$ 9 vol4 xxi41 page #bce1 ( ! ,transactions ( ! ,am]ican ,in/itute ( ,electrical ,eng9e]s4 ,^! p9s are design$ to resi/ a uni=m pull at ! small] end & at "r angles to ! axis 9 ea* case4 ,! l5g? ( ea* p91 9 in*es betwe5 ! %\ld] & ! ?read$ end1 is repres5t$ by ,l1 & ! diamet] ( ea* p9 at its %ank by ,d4 ,l4 ,d4 #a #j4hg #b #a4aj #c #a4bf #d #a4ci #e #a4ej #f #a4ei #g #a4fg #h #a4ge #i #a4hb #aj #a4hh #aa #a4ie #ac #b4jf #ae #b4ag #ag #b4be #ai #b4cd #ba #b4db ,! two /ronge/ p9s 9 ,table ,,ii4 appe> to be ^? 9 use on ! l9e betwe5 ,%aw9igan ,falls & ,montreal & on ! l9e f ,niag>a ,falls to ,buffalo4 ,! =m] h a diamet] ( #b-c_/d in*es at ! %ank1 & ! wire is c>ri$ #af-a_/d in*es above ! %\ld] ( ! p94 ,on ! new ,niag>a l9e ! %ank diamet] ( ea* p9 is only #b-a_/d in*es1 b ! l9e wire is only #aj in*es above ! %\ld]4 ,x 0 f\nd by te/s t a /ra9 ( #b1ajj p\nds at ! top ( ! insulator & at "r angles to ! axis ( ?is ,niag>a p9 0 necess>y to break x at ! %ank4 ,?is /ra9 is ab\t six times z great z ! calculat$ maximum /ra9 t w occur 9 s]vice on ! l9e4 ,"s ( ! p9s "h not$ are mu* /rong] ?an ^? propos$ 9 ! above specifications = /&>d p9s4 ,! p9s on ! old ,niag>a l9e h a %ank diamet] ( #b in*es1 ) a /em only #e-a_/d in*es long1 :ile ! propos$ p9 ( #b in*es diamet] at ! %ank has a /em #aa in*es long4 ,on ! ,colgate & ,oakl& l9e a %ank diamet] ( #b-a_/h in*es goes ) a l5g? ( #aj-c_/h in*es 9 ! /em1 b ! propos$ p9 ) ?is size ( %ank has a /em #ac in*es long4 ,= a %ank ( #b-a_/d in*es diamet] ! propos$ p9 has a /em #ae in*es long1 b ! p9s ) ?is diamet] ( %ank on ! ,electra l9e are only #ab in*es long 9 ! /em4 ,! #b-a_/d-;in* diamet] ( %ank 9 ! p9s on ! new ,niag>a l9e goes ) a l5g? ( only #g-c_/d in*es 9 ! /em4 ,! new ,niag>a p9 is ?us almo/ exactly twice z /rong z ! propos$ p91 s9ce ! /r5g? ( a p9 :]e ! %ank jo9s ! /em v>ies inv]sely z ! l5g? ( ! /em1 all o!r factors be+ ! same4 ,p9s on ! ,%aw9igan ,falls l9e h a %ank #b-c_/d in*es 9 diamet]1 ) a l5g? ( #ac-a_/b in*es 9 ! /em2 b ! l>ge/ ( ! propos$ p9s1 t ) a /em #ai in*es long1 has a diamet] ( only #b-a_/b in*es 9 ! %ank4 ,x is h>dly too mu* to say 9 ! int]e/ ( good eng9e]+ t ! wood5 p9 ( ab\t #e in*es l5g? ( /em & #a-a_/b in*es diamet] ( %ank1 z well z all long] p9s ( no great] /r5g?1 %\ld be disc>d$ = long transmission l9es ( high voltage4 ,^! p9s h done good s]vice on telegraph & telephone l9es1 & on local light+ circuits ( ,no4 #f ,b4 ,s4 gauge wire or small]1 & !y may well be left = su* "w4 ,to meet ! conditions ( transmission "w a *ange 9 bo? ! %ape & size ( p9s is necess>y4 ,9 ! fir/ place1 ! %\ld] on p9s :]e ! %ank & /em meet1 t relic ( telegraph practice1 %\ld be entirely disc>d$4 ,?is *ange w save consid]able lumb] on p9s ( a giv5 diamet] at ! %ank1 & w increase ! /r5g? ( ! p9 by avoid+ ! %>p corn] at ! junction ( ! %ank & /em4 ,ano!r *ange ( design %\ld leave an excess ( /r5g? 9 ! /em ( ! p91 to provide = det]ioration ( ! wood1 & p>ticul>ly = *>r+ by curr5t breakage4 ,?is increase ( diamet] & /r5g? ne> ! top ( ! p9 w co/ no?+ 9 lumb]1 = ! wood is necess>ily !re unless x is turn$ (f4 ,! %ank ( ea* p9 %\ld be proportionately %ort] ?an 9 ! old] type1 & ! p9 hole %\ld be bor$ only "p way ?r\gh ! cross-arm4 ,a sav+ 9 lumb] = p9s & = cross-arms w ?us be made1 s9ce ! size ( ! cross-arm may be less = a giv5 resi/ance to splitt+4 ,) ^! *anges 9 g5]al design ! p9 is a simple cyl9d] 9 ! %ank1 ) a g5tle tap] f ! %ank to =m ! /em4 ,an example ( ?is design1 :i* might well s]ve z a basis = a l9e ( /&>d p9s1 w\ld be a p9 #b in*es 9 diamet] & #c-a_/b in*es long 9 ! %ank1 & tap]+ = a l5g? ( #e in*es f ! %ank to =m ! /em1 ) a diamet] ( #a-a_/b in*es at ! top4 ,! hole 9 a cross-arm = ?is p9 %\ld be #c-a_/b in*es deep1 & ?is1 9 an arm #d-c_/d in*es deep1 w\ld leave #a-a_/d in*es ( wood bel[ ! p94 ,f ! l[] end ( ! p9 hole1 a hole #a_/d-;in* 9 diamet] %\ld run to ! bottom ( ! cross-arm to dra9 (f wat]4 ,a l9e ( long] p9s design$ to resi/ ! same l9e pull z ?is %ort "o w\ld be /rong en\gh = small conductors1 say up to ,no4 #a ,b4 ,s4 gauge wire4 ,= l>g] wires1 long spans & %>p angles 9 a l9e1 a p9 #b-a_/d in*es 9 diamet] & #d-a_/b in*es long 9 ! %ank1 tap]+ = #e in*es to a diamet] ( #a-c_/d in*es at ! top1 or long] p9s ( equal /r5g?1 %\ld be us$4 ,:]e ! p9 holes d n ext5d ?r\gh ! cross-arm !re is no ne$ ( a %\ld] on ! p9 to su/a9 ! weight ( ! l9e wire4 ,9 ! cross-arm on ! new ,niag>a ,falls l9e ea* p9 hole is bor$ to a dep? ( #e in*es1 leav+ #a in* ( wood bel[ ! hole4 ,on ! l9e f ,electra to ,san ,francisco ! dep? ( ea* p9 hole is aga9 #e in*es1 & ! dep? ( ! cross-arm #f in*es4 ,! p9s = use on ! ,electra l9e 7 kept = sev]al h\rs 9 a vat ( l9se$ oil at a temp]ature ( #baj ,f4 ,! p9s = ! ,%aw9igan l9e 7 boil$ 9 /e>ic acid4 ,all wood5 p9s %\ld be treat$ *emically1 b ! object ( ?is treatm5t %\ld be to prev5t decay r ?an to give !m any p>ticul> insulat+ value4 ,! lack ( /r5g? 9 wood5 p9s & _! de/ruction 9 "s cases by curr5t leakage are lead+ to ! use ( iron & /eel p9s4 ,su* a p91 9 use on ! l9es ( ! ,wa%+ton ,p[] ,company1 ( ,spokane1 ,wa%41 is made up ( a mild /eel b> #ag-a_/b in*es long & #a-a_/h in*es 9 diamet]1 ca/ into a %ank at "o end1 s t ! total l5g? is #ah in*es4 ,! ca/-iron %ank has a diamet] ( #b-a_/af in*es1 ) a %\ld] ( #b-a_/b in*es diamet] at its upp] end4 ,to prev5t ! p9 f lift+ out ( its hole a small screw ent]s ! top ( ! cross-arm & be>s on ! top end ( ! %ank4 ,above ! ca/-iron %ank ! l5g? ( ! /eel rod is #ab in*es1 & />t+ #c_/d in* d[n f its top a portion ( ! rod #c_/d in* long is turn$ to a diamet] ( "o in*4 ,x is said t ?is p9 beg9s to b5d ) a pull ( #a1jjj p\nds at its top1 b t x w support ! insulator safely ev5 :5 badly b5t4 ,insulators may resi/ puncture & prev5t surface arc+ f wire to p91 b /ill all[ a l>ge ?\gh sil5t fl[ ( en]gy ov] ! p9s & cross-arms betwe5 ! conductors ( a transmission circuit4 ,! rate at :i* curr5t fl[s f "o wire ( a transmission circuit to ano!r 9 ?is way dep5ds on ! total resi/ance ( ea* pa? ov] insulator surfaces & ?r\gh air to ! p9s & cross-arm1 & !n ov] ^! p>ts4 ,if ! p9s & cross-arm are entirely ( iron1 ! total resi/ance ( ! pa? ?r\gh !m f wire to wire is practically t ( ! insulator surfaces4 ,if ! p9s & cross-arm are ( wood :i* is dry1 !y may (f] an appreciable "p ( ! total resi/ance ( ! pa? ?r\gh !m betwe5 ! wires ( a circuit2 b if ! wood be wet1 its resi/ance is v mu* r$uc$4 ,! resi/ance ( wood5 p9s & cross-arm may be s small comp>$ ) t ( ! air & insulator surfaces t complete ! pa? ?r\gh !m f wire to wire ( a circuit1 t ! effect ( ^! wood5 p>ts 9 *eck+ ! fl[ ( curr5t betwe5 conductors is relatively unimportant1 & yet ! resi/ances ( ^! p9s & ! cross-arm may affect _! la/+ qualities4 ,! curr5t t fl[s ov] ! p9s & cross-arms f "o wire to ano!r ( a high-t5sion circuit may be s small z n to injure ^! wood5 p>ts :5 ev5ly di/ribut$ ov] !m1 & yet ?is same curr5t may *> or burn ! wood if conf9$ to a n>r[ pa?4 ,su* a leakage curr5t w naturally cease to be ev5ly di/ribut$ ov] p9s & _! cross-arms :5 c]ta9 portions ( _! surfaces are ( mu* l[] resi/ance ?an o!rs1 because an electric curr5t divides & foll[s sev]al possible pa?s 9 ! inv]se ratio ( _! resi/ances4 ,^! n>r[ pa?s ( relatively l[ resi/ance along wood5 p9s & cross-arms are heat$ & *>r$ by ! v curr5t t !y attract1 s t ! conductivity ( ! pa? & ! heat develop$ !re9 react mutually to increase ea* o!r1 & t5d t[>d ! de/ruction ( ! wood4 ,among causes t t5d to make "s p>ts ( p9s & cross-arms bett] conductors ?an o!rs1 !re may be m5tion$ cracks 9 ! wood1 :]e dirt & moi/ure collect1 du/1 ) a mixture ( salt deposit$ on ! wood by ! w9ds at c]ta9 places1 & sea fogs t are (t5 bl[n only aga9/ "o side ( ! p9s & arms & deposit salt4 ,to make matt]s worse1 ! same cause t creates a pa? ( relatively good conductivity along wood5 p9s & cross-arms (t5 mat]ially l[]s ! resi/ance (f]$ to ! leakage ( curr5t by ! insulator surfaces4 ,?us an increase ( ! rate at :i* en]gy passes f wire to wire ( a circuit1 & ! conc5tration ( ?is en]gy 9 c]ta9 p>ts ( ! wood5 pa?1 are sometimes br\ght ab\t at ! same "t4 ,:]e ! l9e insulators employ$ are s design$ t ! resi/ance ( ! dry wood5 p9s & cross-arms =ms a mat]ial "p ( ! total resi/ance betwe5 ! wires ( a circuit1 a ra9 or heavy fog may cause a v l>ge increase 9 ! rate at :i* en]gy passes ov] ^! wood5 p>ts betwe5 ! conductors4 ,z long z only mod]ate voltages 7 c>ri$ on l9e conductors1 ! *>r+ & burn+ ( _! p9s & cross-arms 0 a v unusual matt]2 b ) ! application ( v high pressures on long circuits ! de/ruction ( ^! wood5 p>ts by ! heat ( leakage curr5ts has become a s]i\s m5ace to transmission sy/ems4 ,ev5 ) l[ voltages !re may be *>r+ & burn+ ( p9s & cross-arms if ! l9e insulators are v poor or if ! conditions z to wea!r & fly+ du/ are suffici5tly sev]e4 ,9 vol4 xx4 ( ! ,transactions ( ! ,am]ican ,in/itute ( ,electrical ,eng9e]s1 pages #dce to #ddb & #dga to #dgi1 an acc\nt ( ! *>r+ & burn+ ( p9s on sev]al transmission l9es is giv51 f :i* "s ( ! foll[+ examples are tak54 ,9 "o case a l9e t ran ne> a c]ta9 *emical factory 0 said to be mu* tr\bl$ by ! burn+ ( its p9s1 ?\gh ! voltage employ$ 0 only #ddj1 & ! insulators 7 design$ = circuits ( #aj1jjj volts4 ,9 ra9y wea!r1 :5 insulators1 p9s1 & cross-arms 7 wa%$ cle> ( ! *emical deposits1 !re 0 no p9 burn+4 ,simil> tr\ble has be5 met ) on sections ( ! #dj1jjj-volt ,provo l9e1 9 ,utah1 :]e du/1 mix$ ) salt1 is deposit$ on ! insulators1 p9s1 & cross-arms4 ,on page #gjh a #b1jjj-volt l9e is m5tion$ on :i* fog1 du/1 & ra9 caus$ mu* burn+ ( p9s4 ,:5 circuits are op]at$ at voltages ( #dj1jjj to #fj1jjj1 no v sev]e climatic conditions are necess>y to develop s]i\s tr\ble 9 ! wood5 p9s by leakage curr5ts1 ev5 :]e ! transmission l9es are support$ 9 insulators ( ! l>ge/ & be/ types yet develop$4 ,/rik+ examples along ?is l9e may be se5 9 ! transmission sy/ems betwe5 ,colgate & ,oakl&1 ,cal41 & betwe5 ,electra & ,san ,francisco4 ,bo? ( ^! sy/ems 7 design$ to transmit en]gy at #fj1jjj volts1 b ! actual pressure ( op]ation seems to h be5 limit$ to ab\t #dj1jjj volts dur+ mu* ( _! p]iod ( s]vice4 ,insulators ( a s+le type & size are us$ on bo? ( ^! transmission l9es1 & are among ! l>ge/ ev] put into s]vice on long circuits4 ,ea* ( ^! insulators is #aa in*es 9 diamet]1 & #aa-a_/d in*es high f ! l[] edge to ! top1 ! l9e wire be+ c>ri$ 9 a c5tral top groove4 ,! wood5 p9s us$ on ! two l9es v>y a little 9 size1 s t on ! ,electra l9e ea* p9 /&s #aa-a_/b in*es above its cross-arm1 :ile on ! ,colgate l9e ! correspond+ di/ance is #ab in*es4 ,z ! insulators are ( ! same size 9 ea* case1 ! l5g? ( ! p9 betwe5 ! l[] edge ( ea* insulator & ! top ( ! cross-arm is #d in*es on ! ,colgate l9e & #c-a_/b in*es on ! ,electra l9e4 ,on ! latt] l9e a porcela9 sleeve1 entirely sep>ate f & mak+ no contact ) ! insulator1 cov]s ea* p9 f ! top ( its cross-arm to a po9t above ! l[] edge ( ! insulator4 ,on ! ,colgate l9e ea* insulator makes contact ) its p9 = a l5g? ( #b-a_/b in*es d[n f ! top ( its ?read1 & on ! ,electra l9e ! contact ( ea* insulator ) its p9 runs d[n #c-a_/b in*es bel[ ! top ( ! ?read4 ,?is leaves #i in*es 9 ! l5g? ( ! p9 betwe5 ! insulator contact & ! top ( ea* cross-arm on ! ,colgate l9e1 & a correspond+ l5g? ( p9 am\nt+ to #h-a_/b in*es on ! ,electra l9e4 ,( ?is #h-a_/b in*es ( p9 surface1 ab\t #f in*es is cov]$ by ! porcela9 insulat+ sleeve us$ on ea* p9 ( ! ,electra l9e1 s t only ab\t #b-a_/b in*es ( ! l5g? ( ea* p9 on t l9e is expos$ to ! leakage ( curr5t f ! insulator directly ?r\gh ! air4 ,bo? ! sizes ( p9s j m5tion$ 7 made ( eucalyptus wood1 boil$ 9 l9se$ oil4 ,ea* "o ( ?ree p9s tak5 f a pole1 betwe5 ,nor? ,tom] & ,cordelia1 on ! ,colgate l9e1 0 badly *>r$ & burn$ on its side t fac$ ! damp ocean w9ds4 ,?is *>r+ ext5d$ all ! way d[n ea* p9 f ! po9t :]e ! insulator made contact ) x1 a little "u ! ?reads1 to ! top ( ! cross-arm n9e in*es bel[4 ,two ( ^! p9s 7 locat$ at ! opposite ends ( a cross-arm1 & ! ?ird 0 fix$ 9 ! top ( ! pole4 ,?is cross-arm 0 *>r$ or burnt1 z well z ! p91 b no defects c\ld be detect$ 9 ! insulators t ! p9s support$4 ,z to ^! ?ree p9s1 ! mo/ reasonable explanation seems to be t en\gh curr5t leak$ ov] bo? ! outside & inside surfaces ( ea* insulator & ?r\gh ! air to *> ! p9 & cross-arm4 ,9 fl[+ d[n ea* p91 ! curr5t 0 naturally conc5trat$ on ! side expos$ to ! damp w9ds ( ! ocean1 because ! deposit ( moi/ure by ^! w9ds l[]$ ! resi/ance on t side4 ,:5 ^! w9ds 7 n bl[+1 & be=e a p9 became *>r$ on "o side1 its resi/ance 0 probably ab\t ! same all ! way ar\nd1 & ! leakage curr5t1 be+ di/ribut$ ov] ! p91 0 n suffici5t to *> x4 ,! damp w9d w\ld1 ( c\rse1 l[] ! surface resi/ance ( ea* insulator1 & ?is1 ) ! deposit ( moi/ure on ! p9s & cross-arm1 _m h made a v mat]ial r$uction 9 ! total resi/ance f wire to wire4 ,! insulators us$ on ^! p9s ea* _h two petticoats1 an upp] "o1 #aa in*es 9 diamet]1 & a l[] "o1 #f-a_/b in*es 9 diamet]1 ! l[] edge ( ! small] petticoat be+ #g-a_/b in*es b5ea? ! l[] outside edge ( ! l>g] petticoat4 ,z ! inn] surface ( ! l>g] petticoat 0 mu* ne>] to a horizontal plane ?an ! inn] surface ( ! small] petticoat1 moi/ure w\ld h be5 m readily reta9$ on x1 & ! great] "p ( ! surface resi/ance ( ! insulator dur+ wet wea!r mu/ !re=e h be5 on ! inside ( ! small] petticoat4 ,at its l[] edge ! small] petticoat 0 di/ant radially ab\t #a-c_/d in*es f ! p91 & ! di/ance betwe5 ! p9 & ! inside surface ( ! small] petticoat gradually decreas$ to actual contact at a po9t #e-a_/b in*es above ?is l[] edge4 ,! pa? ( ! curr5t f ! l9e wire to ! p9 9 ?is case seems to h be5 fir/ ov] ! entire insulator surface to ! l[] edge ( ! small] petticoat & !n p>tly up ov] ! inn] surface ( ?is petticoat & p>tly f t surface ?r\gh ! air4 ,on ea* ( ^! ?ree p9s ! *>r+ 0 q z bad j bel[ ! ?read z x 0 fur!r d[n1 s t a l>ge "p ( ! leakage curr5t seems to h gone up ov] ! int]ior surface ( ! small] petticoat4 ,! *>r$ portion ( ^! p9s ext5d$ b little1 if at all1 into ! ?reads ne> ! tops or into ! "p ( ! p9 fitt+ into ! cross-arm4 ,! pres]vation ( ! "p ( ea* p9 t ent]$ ! cross-arm seems to h be5 due to ! increase ( surface & decrease ( resi/ance ( ! cross-arm 9 comp>ison ) ! p94 ,pres]vation ( ! ?read$ "p ( ea* p9 seems to h be5 due to its protection f moi/ure & its high resi/ance1 s t little or no curr5t pass$ ov] x4 ,ano!r p9 tak5 f ! same l9e z ! ?ree j consid]$ 0 badly burn$ at a po9t ab\t #a4ge in*es bel[ ! ?reads1 b on saw+ x completely across at two po9ts bel[ ! *>r$ spot ! entire section 0 f\nd to be p]fectly s\nd & free f any sign ( burn+4 ,! explanation ( ! condition ( ?is p9 is1 p]haps1 t ! resi/ance ( ! burn$ "p1 ow+ to its additional protection & dryness1 0 high comp>$ ) t ( ! l[] "p ( ! p91 & ?us develop$ mo/ ( ! heat on ! passage ( curr5t4 ,x is n cle>1 h[ev]1 :y ?is p9 %\ld burn only j bel[ ! ?read1 :ile o!r p9s ( ! same k9d on ! same l9e 7 *>r$ all ! way d[n f ! ?read to ! cross-arm4 ,ano!r curi\s result notic$ 9 "s p9s on ?is same l9e is ! s(t5+ ( ! ?reads s t !y c be rubb$ (f ) ! f+]s4 ,,relation ,,( ,,p9s ,,& ,,insulators4 ---------------------------------------- -------------------------- ,voltage,diamet] ,height ,l5g? ( ,p9 ,location ( ,l9e4 ( ( ( ,cov]$ by ,l9e4 ,insula- ,insula- ,insulator4 tor4 tor4 ---------------------------------------- -------------------------- ,in*es4 ,in*es4 ,in*es4 ,electra to ,san ,francisco #fj1jjj #aa #aa-a_/d #ab ,colgate to ,oakl& #fj1jjj #aa #aa-a_/d #h ,caon ,f]ry to ,butte #ej1jjj #i #ab #aj-a_/b ,%aw9igan ,falls to ,montreal #ej1jjj #aj #ac #aj-a_/d ,santa ,ana ,riv] to ,los ,angeles #cc1jjj #f-c_/d #d-g_/h #b-a_/b ,provo ar\nd ,utah ,lake #dj1jjj #g #e-c_/d #d-c_/d ,spi] ,falls to ,s*5ectady #cj1jjj #h-a_/b #f-c_/d #e-a_/d ,niag>a ,falls to ,buffalo #bb1jjj #g-a_/b #g #e ---------------------------------------- -------------------------- ,! s(t5$ wood ( ! ?reads is n *>r$1 b is said to h a s\r ta/e & to resemble dige/$ wood pulp4 ,:ile ! ?reads ( a wood5 p9 are de/roy$ 9 ?is way ! rema9d] ( ! p9 may /ill rema9 p]fect & %[ no *>r+4 ,,relations ,,( ,,p9s ,,& ,,insulators4 ---------------------------------------- --------------------- ,l5g? ( ,di/ance ,di/ance ,p9 f ,out]f ,l[e/ ,location ( ,l9e4 ,betwe5 ,petticoat ,petticoat ,insula- to ,p9 to ,p9 tor & ,?r\gh ,?r\gh ,cross-arm4 ,air4 ,air4 ---------------------------------------- --------------------- ,in*es4 ,in*es4 ,in*es4 ,electra to ,san ,francisco #j #aj-a_/b #c-a_/b ,colgate to ,oakl& #c-a_/b #aj #b-a_/b ,caon ,f]ry to ,butte #a-a_/b #j #a-a_/b ,%aw9igan ,falls to ,montreal #c-a_/d #i-a_/b #a ,santa ,ana ,riv] to ,los ,angeles #c-a_/b #b-c_/d 44 ,provo ar\nd ,utah ,lake #c-a_/b #b-a_/b 44 ,spi] ,falls to ,s*5ectady #d #d #e_/h ,niag>a ,falls to ,buffalo #c #d-a_/b #b ---------------------------------------- --------------------- ,9 explanation ( ?is dis9tegration ( ! ?reads ( wood5 p9s x 0 /at$ t a numb] ( ^! p9s1 ! tops ( :i* 7 r$uc$ to a :ite p[d]1 _h be5 tak5 f ! l9e betwe5 ,niag>a ,falls & ,buffalo1 on :i* ! voltage is #bb1jjj1 & t ?is p[d] prov$ on analysis to be a nitrate salt4 ,?is salt 0 ?\ght to be ! result ( ! action ( nitric acid on ! wood1 x be+ suppos$ t ! acid 0 =m$ by a /atic dis*>ge act+ on ! oxyg5 & nitrog5 ( ! air betwe5 ! ?reads ( ! insulator & p94 ,9 support ( ?is view x 0 /at$ t an exp]im5tal l9e ( galvaniz$-iron wire at ,niag>a ,falls1 :i* 0 op]at$ at #ge1jjj volts cont9u\sly dur+ ne>ly f\r mon?s1 turn$ black ov] its entire l5g? ( ab\t two miles4 ,?is surface dis9tegration 0 n due to ! normal action ( ! air1 = simil> wire at ! same place rema9$ bright :5 n us$ z an electrical conductor4 ,^! facts seem$ to indicate t ! bru% dis*>ge f ! wires c>ry+ ! #ge1jjj-volt curr5t develop$ nitric acid f ! oxyg5 & nitrog5 ( ! air1 & t ?is acid attack$ ! wire4 ,"o ( ! above-m5tion$ p9s us$ on ! ,electra l9e 0 mu* *>r$ & burn$ away at a po9t a little bel[ ! ?reads4 ,! *>r$ pa? ( ! curr5t c\ld also be trac$ d[n ! side ( ! p9 to ! cross-arm1 b ?is pa? 0 n z badly burn$ z ! spot ne> ! top ( ! p94 ,a composite p9 f a #cc1jjj-volt l9e1 probably a "p ( ! transmission sy/em betwe5 ! ,santa ,ana ,riv] & ,los ,angeles1 0 burn$ ?r\gh its wood5 ?reads to ! c5tral iron bolt1 along a n>r[ /rip at "o side4 ,e p9 burn$ on ?is l9e 0 said to %[ ! effects ( ! curr5t 9 ! way j describ$1 b no cross-arms 7 burn$ & v few insulators punctur$4 ,! composite p9 0 made up ( a c5tral iron bolt #aj-e_/h in*es long1 #a_/b-;in* 9 diamet]1 & ) a ?9 head above ! wood5 ?reads1 a sleeve ( wood #b-e_/h in*es long & #a in* 9 diamet] 9 its ?read$ portion1 & a sleeve ( porcela9 #c-a_/h in*es long & #a-a_/d in*es 9 diamet] at its upp] & #b-aa_/af in*es at its l[] end4 ,! sleeves ( wood & porcela9 7 slipp$ ov] ! c5tral iron bolt s t ! portions ( ! p9 above ! cross-arm measur$ #e-g_/h in*es4 ,9 ?is case ! pa? ( ! leakage curr5t seems to h be5 ov] bo? ! ext]ior & int]ior surface ( ! insulator & !n ?r\gh ! wood5 sleeve to ! c5tral bolt & ! cross-arm4 ,! facts j outl9$ c]ta9ly indicate a s]i\s m5ace to ! p]man5ce & reliability ( long1 high-voltage transmission l9es support$ by insulators on wood5 p9s4 ,if su* results h be5 enc\nt]$ on ! l9es above nam$1 :]e "s ( ! l>ge/ & be/ designs ( insulators are employ$1 x is only fair to assume t simil> de/ructive effects ( leakage curr5ts are tak+ place on _m o!r l9es t op]ate at high voltages4 ,x seems at lea/ d\btful :e!r any enl>gem5t or improvem5t ( ! insulators !mselves w entirely avoid ! de/ruction ( _! wood5 p9s 9 "o ( ! ways m5tion$4 ,x is probable1 b n c]ta91 t fur!r ext5sion ( di/ances ?r\gh air & ov] insulator surfaces1 bo? ext]ior & int]ior1 betwe5 l9e wires & wood5 p9s1 w prev5t *>r+ & burn+ ( ! latt] by leakage curr5ts4 ,mu* has already be5 done 9 ! way ( cov]+ mo/ ( ! p9 above its cross-arm ) ! insulator p>ts1 b ev5 ^? portions ( ! p9 t are be/ protect$ 9 ?is way are n free f burn+4 ,?us1 on ! ,colgate l9e1 eight in*es ( ea* p9 is protect$ by ! int]ior surface ( its insulator1 b ^! p9s 7 *>r$ q z badly :]e be/ protect$1 up close to ! ?read1 z !y 7 d[n ne> ! cross-arm4 ,! same is true ( ! ,electra l9e1 :]e a porcela9 sleeve runs up ab\t ! p9 f ! cross-arm to a po9t above ! inn] petticoat ( ea* insulator1 s t ! entire l5g? ( ! p9 above ! cross-arm is protect$4 ,on ! ,caon ,f]ry l9e1 a glass sleeve t virtually =ms a "p ( ea* insulator1 ?\gh me*anically sep>ate f x1 protects ! p9 f its ?read$ portion to )9 #a4e in*es ( ! cross-arm4 ,insulators on ! l9e f ,%aw9igan ,falls to ,montreal are ea* #ac in*es long & ext5d d[n ov] ! p9 to )9 #a4e in*es ( ! cross-arm4 ,! burn$ portion ( ea* p9 f ! ,santa ,ana l9e 0 t c>ry+ ! ?reads1 & ?us 9 actual contact ) t "p ( ! insulator :i* 0 sep>at$ by ! greate/ surface di/ance f ! l9e wire4 ,aside f ! burn+ ( p9s is ! de/ruction ( _! ?read$ p>ts by "s *emical ag5cy t is develop$ inside ( ! tops ( ! insulators1 z %[n 9 ! cases ( ! ,colgate & ,niag>a l9es4 ,x does n appe> t any improvem5t ( insulators w necess>ily prev5t *emical action4 ,?\gh x may n be practicable to s increase ! surface resi/ance ( ea* insulator t ! burn+ ( wood5 p9s by leakage curr5t w be prev5t$1 ! sub/itution ( a conduct+ = an insulat+ p9 may rem$y ! tr\ble4 ,z ! insulators1 p9s1 & cross-arm =m a pa? = ! leakage curr5t f wire to wire1 ! wood5 p9s by _! resi/ance1 especially :5 dry1 mu/ develop heat4 ,9 p9s ( /eel or iron ?is heat w\ld be trifl+ & w\ld d no damage4 ,) p9s ( good conduct+ mat]ial1 l iron1 ! am\nt ( leakage f wire to wire1 ) a giv5 design ( insulator1 w\ld1 no d\bt1 be some:at great] ?an ! leakage ) wood5 p9s4 ,x w be *eap]1 h[ev]1 to increase ! resi/ance ( new insulators up to ! comb9$ resi/ance ( pres5t insulators & _! wood5 p9s ?an x w be to replace ^! p9s :5 !y are burn$4 ,f all ! evid5ce at h&1 x seems t insulators :i* r$uce ! leakage ( curr5t ov] _! surfaces to p]missible limits z f> z m]e loss ( en]gy is conc]n$1 ev5 ) iron p9s1 w n prev5t ! *>r+ & de/ruction ( wood5 p9s4 ,illu/ration3 ,,fig4 #ij4--;,glass ,insulator & ,sleeve on #ej1jjj-volt ,l9e ,betwe5 ,caon ,f]ry & ,butte1 ,mont4 ,:5 any suitable insulator is dry & clean x (f]s all necess>y resi/ance to ! leakage ( curr5t ov] its surface1 & any resi/ance 9 ! p9 t c>ries ! insulator is ( small importance4 ,if ! resi/ance ( an insulator ne$s to be re9=c$ by t ( its p9 9 any case1 x is :5 ! surface ( ! insulator is wet or dirty4 ,un=tunately1 h[ev]1 ! same wea!r conditions t deposit dirt or moi/ure on an insulator make simil> deposits on its p91 & ! resi/ance ( ! p9 is l[]$ mu* m ?an t ( ! insulator by su* deposits4 ,! increase ( curr5t leakage ov] ! surface ( an insulator dur+ ra9s & fogs usually does no damage to ! insulator itself1 b su* leakage ov] ! wet p9 soon develops a surface lay] ( c>bon t cont9ues to act z a good conductor aft] ! moi/ure t tempor>ily l[]$ ! resi/ance has gone4 ,reasons l ^! h l$ "s eng9e]s to pref] iron p9s ) insulators t (f] all ( ! resi/ance necess>y = ! voltage employ$ on ! l9e4 ,x may be sugge/$ t ! use ( iron p9s w transf] ! *>r+ & burn+ to ! wood5 cross-arms1 b ?is does n seem to be a necess>y result4 ,! comp>ative fre$om ( cross-arms f *>r+ & burn+ :]e wood5 p9s are us$ seems to be due to ! l>g] surface & l[] resi/ance ( ! cross-arms4 ,) iron p9s hav+ a %ank ( small diamet]1 s t ! area ( contact surface betwe5 ! p9 & ! wood5 cross-arm is relatively small1 !re may be "s *>r+ ( ! wood at ?is contact surface4 ,%\ld x be ?\ght desirable to gu>d aga9/ any tr\ble ( ?is sort1 ! surface ( ! iron p9 9 contact ) ! cross-arm may be made ample by ! use ( l>ge wa%]s1 or by giv+ ea* p9 a great] diamet] at ! %ank ?an else:]e4 ,x may be not$ t ! p9s ) a c5tral iron bolt only half an in* 9 diamet]1 t 7 us$ on ! #cc1jjj-volt ,santa ,ana l9e1 7 said to h caus$ no burn+ ( _! cross-arms 9 ^? cases 9 :i* ! wood5 ?reads ab\t ! top ( ! c5tral bolt 7 burn$ ?r\gh4 ,ano!r possible tr\ble ) iron p9s is t !y1 by _! great] rate ( expansion ?an glass or porcela91 w break _! insulators4 ,su* results c readily be avoid$ by cem5t+ ea* iron p9 into its insulator1 in/ead ( screw+ ! insulator onto ! p94 ,iron p9s w1 no d\bt1 co/ some:at m ?an ^? ( wood1 b ?is co/ w 9 any ev5t be only a small p]c5tage ( ! total inve/m5t 9 a transmission l9e4 ,consid]+ ! co/ ( ! r5ewals ( wood5 p9s1 !re seems little d\bt t on a l9e :]e ! voltage & o!r conditions are su* z to result 9 frequ5t burn+1 iron p9s w\ld be *eap] 9 ! end4 ,iron p9s h already be5 adopt$ on a numb] ( high-voltage l9es4 ,n only iron p9s1 b ev5 iron cross-arms & iron poles are 9 use on a numb] ( transmission l9es4 ,on a long l9e n[ "u con/ruction 9 ,mexico1 iron t[]s1 plac$ z mu* z #djj feet ap>t1 are us$ in/ead ( wood5 poles1 & bo? ! p9s & cross-arms are also ( iron4 ,! #ge-mile l9e f ,niag>a ,falls to ,toronto is c>ri$ entirely on /eel t[]s4 ,! ,vanc\v] ,p[] ,company1 ,vanc\v]1 ,briti% ,columbia1 use a p9 t consi/s ( a /eel bolt ab\t #ab in*es long fitt$ ) a sleeve ( ca/ iron #d-a_/b in*es long to ent] ! cross-arm1 & a lead ?read to screw into ! insulator4 ,on ! #aaa-mile l9e ( ! ,wa%+ton ,p[] ,company1 ( ,spokane1 :i* 0 design$ to op]ate at #fj1jjj volts & runs to ! ,/&>d & ,hecla m9es1 a p9 consi/+ ( a /eel b> #a-a_/h in*es 9 diamet]1 ) a ca/-iron %ank #b-a_/af in*es 9 diamet] to ent] ! cross-arm1 & ) ! lead ?reads = ! insulator1 is us$4 ,illu/ration3 ,,fig4 #ib4--;,iron ,p9s on ,spi] ,falls ,l9e4 ,on ! network ( transmission l9es betwe5 ,spi] ,falls1 ,s*5ectady1 ,albany1 & ,troy1 9 ! ,/ate ( ,new ,york1 ! insulators are support$ on iron p9s ( two types4 ,"o ( ^! p9s1 us$ at corn]s & :]e ! /ra9 on ! wire l9e is exceptionally heavy1 is made up ( a wr\ght-iron bolt #c_/d-;in* 9 diamet] & #af-a_/b in*es long ov] ! head1 & ( a malleable iron ca/+ #h-c_/d in*es long4 ,?is ca/+ has a flange ( #e by #c-c_/d in*es at its l[] end t re/s on ! top ( ! cross-arm1 & ! bolt passes f ! top ( ! ca/+ d[n ?r\gh x & ! cross-arm4 ,?reads are cut on ! l[] end ( ! bolt1 & a nut & wa%] secure x 9 ! cross-arm4 ,! total height ( ?is p9 above ! cross-arm is #i-a_/d in*es4 ,= /raight "w on ?is l9e a p9 ) /em entirely ( malleable iron1 & a bolt t comes up ?r\gh ! cross-arm & ent]s ! base ( ! ca/+1 is us$4 ,! ca/ top ( ?is p9 has f\r v]tical webs1 & its rectangul> base1 :i* re/s on ! top ( ! cross-arm1 is #c-a_/b by #d in*es4 ,! bolt t comes up ?r\gh ! cross-arm & taps into ! base ( ! ca/+ is #c_/d-;in* 9 diamet]4 ,! ca/ "p ( ?is p9 has su* a l5g? t ! top ( its insulator is c>ri$ #aj-c_/d in*es above ! cross-arm4 ,= ! ca/+ ! l5g? is #i-a_/d in*es4 ,bo? ( ! types ( iron p9s 9 use on ! ,spi] ,falls l9es are secur$ to _! insulators ) ,portl& cem5t p\r$ into ! p9 hole :ile liquid :5 ! insulator is upside d[n & ! p9 is held c5trally 9 its hole4 ,! top ( ea* ca/+ is small] 9 diamet] ?an ! hole 9 ! insulator1 & is groov$ s z to hold ! cem5t4 ,illu/ration3 ,,fig4 #ic4--,/&>d ,p91 ,toronto & ,niag>a ,l9e4 ,on a long l9e design$ = #fj1jjj volts1 & rec5tly complet$ 9 ,cali=nia1 wood5 p9s are us$ ) porcela9 insulators1 ea* #ad in*es 9 diamet] & #ab-a_/b in*es high4 ,ea* ( ^! p9s is entirely cov]$ ) %eet z9c f ! cross-arm to ! ?read$ end1 & x is expect$ t ?is metal cov]+ w protect ! wood ( ! p9 f injury by ! leakage curr5t4 ,,*apt] ,,xxi4 ,,insulators ,,= ,,transmission ,,l9es4 ,l9e insulators1 p9s1 & cross-arms all g to make up pa?s ( m or less conductivity betwe5 ! wires ( a transmission circuit4 ,! am\nt ( curr5t fl[+ along ^! pa?s f "o conductor to ano!r 9 any case w dep5d on ! comb9$ resi/ance ( ! insulators1 p9s1 & cross-arm at ea* pole4 ,z a g5]al rule1 ! wires ( high-voltage transmission circuits are us$ b>e because cont9u\s cov]+s w\ld add mat]ially to ! co/ ) only a trifl+ increase 9 effective insulation aga9/ high voltages4 ,9 "s in/ances ! wires ( high-pressure transmission l9es h individual cov]+s = %ort di/ances :]e !y ent] cities1 b (t5 ?is is n ! case4 ,at ,man*e/]1 ,n4 ,h41 b>e conductors f wat]-p[] plants ent] ! sub-/ation1 well )9 ! city limits1 at #ab1jjj volts4 ,f ! wat]-p[] at ,*ambly ! b>e #be1jjj-volt circuits1 aft] cross+ ! ,/4 ,lawr5ce ,riv] ov] ! great ,victoria bridge1 pass ov]head to a t]m9al-h\se ne> ! wat]-front 9 ,montreal4 ,9 ord] to rea* ! ,g5]al ,electric ,works1 ! #cj1jjj-volt circuits f ,spi] ,falls ent] ! city limits ( ,s*5ectady1 ,n4 ,y41 ) b>e ov]head conductors4 ,:]e transmission l9es pass ov] a t]ritory expos$ to corrosive gases1 x is sometimes desirable to give ea* wire a wea!r-pro( cov]+4 ,an in/ance ( ?is sort occurs ne> ,niag>a ,falls :]e ! alum9um conductors =m+ "o ( ! circuits to ,buffalo are cov]$ ) a braid t is saturat$ ) asphaltum = "s di/ance4 ,ea* pa?1 =m$ by ! surface ( ! insulators ( a l9e & ! p9s & cross-arm by :i* !y are support$1 n only wa/es ! en]gy repres5t$ by ! leakage curr5t pass+ ov] x1 b may lead to ! *>r+ & burn+ ( ! p9s & cross-arm by ?is curr5t4 ,to prev5t su* burn+1 ! ma9 reliance is to be plac$ 9 ! surface resi/ance ( ! insulators r ?an t ( p9s & cross-arms4 ,^! insulators %\ld be made ( glass or porcela91 & %\ld be us$ dry--t is1 )\t oil4 ,9 "s ( ! e>ly transmission l9es1 insulators 7 us$ on :i* ! l[] edges 7 turn$ inw>d & upw>d s t a circul> tr\gh 0 =m$ b5ea? ! body ( ! insulator1 & ?is tr\gh 0 fill$ ) heavy petroleum4 ,x 0 f\nd1 h[ev]1 t ?is tr\gh ( oil s]v$ to collect dirt & ?us t5d$ to l[] ! insulation betwe5 wire & cross-arm1 s t ! practice 0 soon ab&on$4 ,glass & porcela9 insulators are rivals = use on high-t5sion l9es1 & ea* has advantages ( its own4 ,porcela9 insulators are mu* /rong] me*anically ?an are ^? ( glass1 & are n liable to crack because ( unequal int]nal expansion1 a result sometimes met ) :]e glass insulators are expos$ to a hot morn+ sun4 ,9 favor ( glass insulators x may be said t _! insulat+ prop]ties are q uni=m1 & t1 unlike porcela91 _! int]nal defects are (t5 app>5t on inspection4 ,9 ord] to avoid int]nal defects 9 l>ge porcela9 insulators1 x has be5 f\nd necess>y to manufacture "s designs 9 sev]al p>ts & !n cem5t ! p>ts ( ea* insulator toge!r4 ,defective insulators may be divid$ into two classes--^? t ! l9e voltage w puncture & break & ^? t p]mit an excessive am\nt ( curr5t to pass ov] _! surfaces to ! p9s & cross-arms4 ,:]e an insulator is punctur$ & brok51 ! p91 cross-arm1 & pole to :i* x is atta*$ are liable to be burn$ up4 ,if ! leakage ( curr5t ov] ! surface ( an insulator is l>ge1 n only may ! loss ( en]gy on ! l9e :]e ! insulator is us$ be s]i\s1 b ?is en]gy foll[s ! p9s & cross-arm 9 its pa? f wire to wire1 & gradually *>s ! =m]1 or bo?1 s t !y are ultimately set on fire or break ?r\gh lack ( me*anical /r5g?4 ,! dis*>ge ov] ! surface ( an insulator may be s l>ge 9 am\nt z to h a disruptive "*1 & ?us to be readily visible4 ,m frequ5tly ?is surface leakage ( curr5t ov] insulators is ( ! invisible & sil5t sort t nev]!less may be suffici5t 9 am\nt to *>1 weak51 & ev5 ultimately set fire to p9s & cross-arms4 ,all insulators1 :e!r made ( glass or porcela91 %\ld be te/$ electrically to det]m9e _! ability to resi/ puncture1 & to hold back ! surface leakage ( curr5t1 be=e !y are put into practical use on high-t5sion l9es4 ,exp]i5ce has %[n t inspection alone _c be dep5d$ on to detect defective glass insulators4 ,electrical te/+ ( insulators s]ves well to det]m9e ! voltage to :i* !y may be subject$ 9 practical s]vice ) little dang] ( puncture by ! disruptive passage ( curr5t ?r\gh _! sub/ance4 ,x is also possible to det]m9e ! voltage t w cause a disruptive dis*>ge ( curr5t ov] ! surface ( an insulator1 :5 ! out] "p ( ?is surface is ei!r wet or dry4 ,?is is z f> z electrical te/s are usually c>ri$1 b x seems desirable t su* te/s %\ld also det]m9e ! am\nt ( sil5t1 invisible leakage ov] ! surface ( insulators bo? :5 !y are wet & :5 !y are dry1 at ! voltage :i* _! circuits are int5d$ to c>ry4 ,su* a te/ ( sil5t leakage is important because ?is sort ( leakage *>s & weak5s insulator p9s1 & sets fire to !m & cross-arms1 besides repres5t+ a wa/e ( en]gy4 ,! voltage employ$ to te/ insulators %\ld v>y 9 am\nt accord+ to ! purpose = :i* any p>ticul> te/ is made4 ,glass & porcela91 l _m o!r solid insulators1 w )/& a voltage dur+ a few m9utes t w cause a puncture if cont9u$ indef9itely4 ,9 ?is respect ^! insulators are unlike air1 :i* all[s a disruptive dis*>ge at once :5 ! voltage to :i* x is expos$ rea*es an am\nt t ! air _c p]man5tly )/&4 ,because ( ?is prop]ty ( glass & porcela9 insulators1 x is necess>y 9 mak+ a puncture te/ to employ a voltage mu* high] ?an t to :i* !y are to be p]man5tly expos$4 ,9 good practice x is ?\ght desirable to te/ insulators = puncture ) at lea/ twice ! voltage ( ! circuits :i* !y w be requir$ to p]man5tly support on transmission l9es4 ,= ! fir/ transmission l9e f ,niag>a ,falls to ,buffalo1 :i* 0 design$ to op]ate at #aa1jjj volts1 ! porcela9 insulators 7 te/$ = puncture ) a voltage ( #dj1jjj1 or ne>ly f\r times t ( ! circuits !y 7 to support4 ,porcela9 insulators = ! second l9e betwe5 ,niag>a ,falls & ,buffalo1 aft] ! voltage ( transmission _h be5 rais$ to #bb1jjj1 7 giv5 a puncture te/ at #fj1jjj volts4 ,( ^! insulators te/$ at #fj1jjj volts only ab\t ?ree p] c5t prov$ to be defective4 ,^! puncture te/s 7 c>ri$ out by plac+ ea* insulator upside d[n 9 an op5 pan conta9+ salt wat] to a dep? ( two in*es1 p>tly fill+ ! p9 hole ( ! insulator ) salt wat]1 & !n connect+ "o t]m9al ( ! te/+ circuit ) a rod ( metal 9 ! p9 hole1 & ! o!r t]m9al ) ! pan4 ,alt]nat+ curr5t 0 employ$ 9 ^! te/s1 z is usually ! case 7,volume xviii41 ,transactions ,a4 ,i4 ,e4 ,e41 pp4 #ead to #ebj74 ,= ! transmission l9es betwe5 ,spi] ,falls1 ,s*5ectady1 ,albany1 & ,troy1 :]e ! voltage is #cj1jjj1 ! insulators 7 requir$ to )/& a punctur+ te/ ) #ge1jjj volts = a p]iod ( five m9utes aft] !y _h be5 soak$ 9 wat] = tw5ty-f\r h\rs4 ,!re is "s diff]5ce ( op9ion z to ! prop] duration ( a punctur+ te/1 ! practice 9 "s cases be+ to cont9ue ! te/ = only "o m9ute on ea* insulator1 :ile 9 o!r cases ! "t runs up to five m9utes or m4 ,z a rule1 ! high] ! te/+ voltage comp>$ ) t "u :i* ! insulators w be regul>ly us$1 ! %ort] %\ld be ! p]iod ( te/4 ,in/ead ( be+ te/$ 9 salt wat] z above describ$1 an insulator may be screw$ onto an iron p9 ( a size t fits its ?reads1 & !n "o side ( ! te/+ circuit put 9 contact ) ! p9 & ! o!r side connect$ ) ! wire groove ( ! insulator4 ,c>e %\ld be tak5 :]e an iron p9 is us$ ei!r 9 te/+ or = regul> l9e "w1 t ! p9 is n screw$ h>d up aga9/ ! top ( ! insulator1 z ?is t5ds to crack (f ! top1 especially :5 ! p9 & insulator are rais$ 9 temp]ature4 ,iron exp&s at a mu* high] rate ?an glass or porcela91 & x is desirable to cem5t iron p9s into insulators r ?an to screw !m 94 ,!re seems to be "s reason to ?9k t an insulator w puncture m readily :5 x is expos$ to sev]e me*anical /ress by ! expansion ( ! iron p9 on :i* x is m\nt$4 ,te/s ( insulators are usually made ) alt]nat+ curr5t1 & ! =m ( ! voltage curve is important1 especially :]e ! te/ is made to det]m9e :at voltage w arc ov] ! surface ( ! insulator f ! l9e wire to ! p94 ,! squ>e root ( ! mean squ>e = two curves ( alt]nat+ voltage or mean effective voltage1 z read by a voltmet]1 may be ! same ?\gh ! maximum voltages ( ! two curves diff] widely4 ,9 te/s = ! puncture ( insulators1 ! av]age alt]nat+ voltage appli$ is m important ?an ! maximum voltage %[n by ! highe/ po9ts ( ! pressure curve1 because ( ! influ5ce ( ! "t elem5t ) glass & porcela94 ,on ! o!r h&1 :5 ! te/ is to det]m9e ! voltage at :i* curr5t w arc ov] ! insulator surface f ! l9e wire to ! p91 ! maximum value ( ! pressure curve %\ld be tak5 into consid]ation because air has no "t elem5t1 b p]mits a disruptive dis*>ge "u a m]ely in/antane\s voltage4 ,alt]nators us$ 9 transmission sy/ems usually con=m approximately to a s9e curve 9 ! in/antane\s values ( ! pressures !y develop1 & x is !re=e desirable t te/s on l9e insulators be made ) voltages ^: values foll[ ! s9e curve4 ,ei!r a s+le trans=m] or sev]al trans=m]s 9 s]ies may be employ$ to /ep up to ! requir$ voltage1 b a s+le trans=m] w usually give bett] regulation & great] accuracy4 ,an air-gap betwe5 ne$le po9ts is n a v satisfactory means by :i* to det]m9e ! av]age voltage on a te/+ circuit1 because1 z already po9t$ out1 ! sp>k+ di/ance betwe5 ! ne$le po9ts dep5ds ma9ly on ! maximum in/antane\s values ( ! voltage1 :i* may v>y ) ! load on ! g5]ator1 & ! saturation ( its magnets4 ,= accurate results a /ep-d[n voltmet] trans=m] %\ld be us$ on ! te/+ circuit4 ,an insulator t resi/s a puncture te/ may fail badly :5 subject$ to a te/ z to ! voltage t w arc ov] its surface f l9e wire to p94 ,?is arc-ov] te/ %\ld be made ) ! out] surface ( ! insulator bo? wet & dry4 ,= ! purpose ( ?is te/ ! insulator %\ld be screw$ onto an iron p91 or onto a wood5 p9 t has be5 cov]$ ) t9foil4 ,"o wire ( ! te/+ circuit %\ld !n be secur$ 9 ! groove ( ! insulator1 & ! o!r wire %\ld be connect$ to ! iron or t9 foil ( ! p94 ,! voltage t w arc ov] ! surface ( an insulator f ! l9e wire to ! p9 dep5ds on ! conditions ( t surface & ( ! air4 ,9 light air1 su* z is f\nd at great elevations1 an arc w jump a great] di/ance ?an 9 dry air ne> ! sea-level4 ,a fog increases ! di/ance t a giv5 voltage w jump betwe5 a l9e wire & its insulator p91 & a heavy ra9 l5g!ns ! di/ance /ill fur!r4 ,! heavi] ! d[np\r ( ra9 ! great] is ! di/ance ov] ! outside surface ( an insulator t a giv5 voltage w arc ov]4 ,! angle at :i* ! fall+ wat] /rikes ! insulator surface also has an influ5ce on ! voltage requir$ to arc ov] t surface1 a deviation f a d[np\r p]p5dicul> to ! plane ( ! l[] edge ( ! petticoat ( ! insulator seem+ to increase ! arc+ di/ance = a giv5 voltage4 ,an insulator %\ld be giv5 an arc-ov] te/ "u conditions t are approximately ! mo/ sev]e to be met 9 practice4 ,^! conditions c p]haps be fairly repres5t$ by a d[np\r ( wat] t am\nts to a dep? ( "o in* 9 five m9utes = ea* squ>e in* ( ! plane includ$ by ! edge ( ! l>ge/ petticoat ( ! insulator1 :5 ! direction ( ! fall+ wat] makes an angle ( =ty-five degrees ) t plane4 ,a precipitation ( "o in* 9 dep? on a horizontal plane dur+ five m9utes seems to be a little great] ?an any record$ by ! ,unit$ ,/ates ,wea!r ,bureau4 ,"u ! sev]e conditions j nam$1 ! voltage requir$ to arc ov] ! insulator surface f l9e wire to p9 %\ld be some:at great] at lea/ ?an ! normal voltage ( ! circuit :]e ! insulator is to be us$4 ,= ! transmission l9e betwe5 ,spi] ,falls & ,s*5ectady1 on :i* ! maximum voltage is #cj1jjj1 ! insulators 7 requir$ to /& a te/ ( #db1jjj volts :5 wet1 )\t arc+ ov] f l9e wire to p94 ,9 ^! wet te/s ! wat] %\ld be spray$ ev5ly onto ! insulator surface l ra91 & ! quantity ( wat] t /rikes ! insulator 9 a giv5 "t %\ld be measur$4 ,:5 ! outside ( an insulator is wet ) ra91 x is evid5t t mo/ ( ! resi/ance betwe5 ! l9e wire & ! insulator p9 mu/ be (f]$ by ! inside surface ( ! petticoat ( ! insulator4 ,= ?is reason an insulator t is to )/& a v high voltage s t no arc w be =m$ ov] its wet outside surface mu/ h a wide1 dry surface "u its petticoat4 ,9 "s te/s ( l9e insulators report$ 9 ,volume xxi41 ,transactions ,a4 ,i4 ,e4 ,e41 p4 #cad1 ! results %[ t ! voltage requir$ to arc ov] f l9e wire to p9 dep5ds on ! %orte/ di/ance betwe5 !m1 r ?an on ! di/ance ov] ! insulator surface4 ,?ree insulators1 numb]$ #d1 #e1 & #g 9 ! trial1 7 9 ea* case te/$ by a gradual increase ( voltage until a dis*>ge took place betwe5 ! wire & p94 ,! p9s 7 coat$ ) t9foil1 & ! te/+ voltage 0 appli$ to ! tie wire on ea* insulator & to ! t9foil ( its p94 ,insulators #d1 #e1 & #g p]mitt$ arcs f wire to p9 :5 expos$ to #gc1hjj1 #gd1gjj1 & #gd1gjj volts respectively1 ! surfaces ( all be+ dry & clean4 ,! %orte/ di/ances betwe5 wires & p9s ov] insulator surface & ?r\gh air 7 #f-e_/h1 #f-a_/d1 & #g-g_/h in*es respectively = ! ?ree insulators1 s t ! arc+ voltages am\nt$ to #aa1adj1 #aa1ieb1 & #i1dgi p] in* ( ^! di/ances4 ,measur$ along _! surfaces1 ! di/ances betwe5 wires & p9s on ^! ?ree insulators 7 #h1 #aa-a_/d1 & #ae-a_/b in*es respectively1 s t ! ?ree arc+ voltages1 :i* 7 ne>ly equal1 am\nt$ to #i1bbe1 #f1fdj1 & #d1hai p] in* ( ^! di/ances4 ,^! figures make x pla9 t ! arc+ voltage = ea* insulator dep5ds on ! %orte/ di/ance ov] its surface & ?r\gh ! air1 f wire to p94 ,x might be expect$ t ! voltage 9 any case w\ld arc equal di/ances ov] clean1 dry insulator surface or ?r\gh ! air1 & ! exp]im5ts j nam$ indicate t ?is view is approximately correct4 ,! sp>k+ di/ance ?r\gh air betwe5 ne$le po9ts1 :i* is great] ?an t betwe5 smoo? surfaces1 is #e4he in*es ) #gj1jjj volts1 & #g4a in*es ) #hj1jjj volts accord+ to ! report 9 ,volume xix41 ,a4 ,i4 ,e4 ,e41 p4 #gba4 ,comp>+ ^! di/ances ) ! %orte/ di/ances betwe5 wires & p9s 9 ! te/s ( insulators numb]$ #d1 #e1 & #g1 :i* broke d[n at #gc1hjj to #gd1gjj volts :5 dry1 x seems t a giv5 voltage w arc some:at fur!r ov] clean1 dry insulator surface ?an x w ?r\gh air4 ,?is view f9ds support f ! fact t only a "p ( ea* ( ! %orte/ di/ances betwe5 wire & p9 0 ov] insulator surface1 ! rema9d] be+ ?r\gh air alone4 ,! fact t ! dry "p ( ! surface ( an insulator & ! air betwe5 its l[] wet edge & ! p9 or cross-arm (f] mo/ ( ! resi/ance betwe5 ! l9e wire & ! p9 & cross-arm is pla9ly br\ght out by ! results ( ! te/s above m5tion$1 9 ! cases ( insulators numb]$ #d & #g4 ,:ile #gc1hjj volts 7 requir$ to arc f l9e-wire to p9 :5 ! entire insulator 0 dry & clean1 ! arc 0 =m$ at only #ec1djj volts dur+ a mod]ate ra9-/orm1 9 ! case ( ,no4 #d insulator4 ,) insulator ,no4 #g ! arc+ voltage 0 #gd1gjj :5 ! entire surface 0 clean & dry1 b ! arc f wire to p9 0 />t$ at #eb1hjj volts dur+ a mod]ate ra94 ,no4 #e insulator seems to pres5t an erratic result1 = :5 dry & clean ! arc jump$ f wire to p9 at #gd1gjj volts1 & yet dur+ a mod]ate ra9 no arc 0 =m$ until a voltage ( #gj1djj 0 rea*$4 ,= ea* ( ! sev5 insulators on :i* te/s are report$ z above1 ! voltage requir$ to arc f l9e wire to p9 0 ne>ly or q z great dur+ a dry sn[-/orm z :5 ! insulator surface 0 clean & dry4 ,:5 ! insulators 7 cov]$ ) wet sn[ _! surface insulation broke d[n at voltages t 7 )9 t5 p] c5t above or bel[ ! arc+ voltages dur+ a mod]ate ra9 9 five cases4 ,) two insulators ! arc+ voltages1 :5 !y 7 cov]$ ) wet sn[1 7 only ab\t sixty p] c5t ( ! voltages necess>y to break d[n ! surface insulation betwe5 wire & p9 dur+ a mod]ate ra94 ,:5 ! outside surface ( an insulator is wet1 z dur+ a mod]ate ra91 x seems t ! "u surface ( ! insulator1 & ! di/ance ?r\gh air f ! l[] wet edge ( ! insulator to ! p9 or cross-arm1 make up mo/ ( ! insulation t prev5ts arc+ ov] f ! wire to ! p9 or cross-arm4 ,x fur!r appe>s t x is useless to ext5d ! di/ance across ! dry "u surface ( ! insulator indef9itely )\t a correspond+ increase ( ! direct di/ance ?r\gh air f ! l[] wet edge ( ! insulator to ! wood ( cross-arm or p94 ,insulator ,no4 #g 9 ! te/s "u consid]ation _h a diamet] at ! l[] edge ( its out] petticoat ( sev5 in*es1 & 0 m\nt$ on a /&>d wood5 p94 ,! diamet] ( ?is p9 9 ! plane ( ! l[] edge ( ! insulator 0 probably ab\t #a-a_/d in*es1 s t ! radial di/ance ?r\gh air f ?is edge to ! p9 mu/ h be5 #b-g_/h in*es approximately4 ,dur+ a mod]ate ra9 ! surface insulation ( ?is insulator broke d[n & an arc 0 =m$ f wire to p9 ) #eb1hjj volts4 ,! sp>k+ di/ance betwe5 ne$le po9ts at #ej1jjj volts is #c4ee in*es1 accord+ to ,volume xix41 ,a4 ,i4 ,e4 ,e41 p4 #gba1 & mu/ be %ort] betwe5 smoo? surfaces1 su* z ! wire & p9 9 "q1 s t ne>ly all ( ! #eb1hjj volts 9 ?is case mu/ h be5 requir$ to jump ! #b-g_/h in*es ( air1 leav+ v little to ov]come ! slight resi/ance ( ! wet outside surface ( ! insulator4 ,on ?is insulator ! surface di/ance f wire to p9 0 #ae-a_/b in*es1 :ile ! %orte/ break+ di/ance 0 only #g-g_/h in*es1 s t ! di/ance across ! dry "u surface ( ! insulator mu/ h be5 #ae-a_/b - 7#g-g_/h - #b-g_/h7 #aj-a_/b in*es approximately4 ,x is evid5tly futile to put a pa? #aj-a_/b in*es long across dry insulator surface 9 p>allel ) a pa? only #b-g_/h in*es long 9 air1 z an arc w c]ta9ly jump ?is %ort] pa? long be=e "o w be =m$ ov] ! long]4 ,! same l9e ( reason+ applies to ,no4 #c insulator 9 ?is te/1 :i* _h a diamet] ( #f-c_/d in*es1 a surface di/ance f wire to p9 ( #ac in*es1 & a m9imum di/ance ( #g-a_/d in*es1 & ^: surface insulation broke d[n at #dh1fjj volts dur+ a mod]ate ra94 ,! necessity ( increas+ ! di/ance betwe5 ! l[] wet edges ( insulators & ! p9s & cross-arm1 z well z ! di/ance across ! dry "u surfaces ( insulators1 l$ to ! adoption ( ! s-call$ umbrella type = "s high-voltage l9es4 ,9 ?is type ( insulator ! ma9 or out] petticoat is giv5 a relatively great diamet]1 & in/ead ( be+ bell-%ap$ is only mod]ately concave on its "u side4 ,) an insulator ( ?is type m\nt$ on a l>ge1 long p91 ! l[] edge ( ! umbrella-l petticoat may be f> remov$ f ! p9 & cross-arm4 ,b5ea? ! l>ge petticoat ( su* insulators = high voltages !re are usually "o or m small] petticoats or sleeves t run d[n ! p91 & increase ! di/ance betwe5 x & ! l[] edge ( ! l>ge/ petticoat4 ,,insulators ,,on ,,transmission ,,l9es4 ---------------------------------------- ------------------------- ,mat]ial ,in*es ,in*es ,voltage ( ,diamet],height ,location ( ,l9e4 ( ,insula- ( ( ,l9e4 tor4 ,insula- ,insula- tor4 tor4 ---------------------------------------- ------------------------- ,electra to ,san ,francisco #fj1jjj,porcela9 #aa #aa-a_/d ,colgate to ,oakl& #fj1jjj,porcela9 #aa #aa-a_/d ,caon ,f]ry to ,butte #ej1jjj;,glass #i #ab ,%aw9igan ,falls to ,montreal #ej1jjj,porcela9 #aj #ac-a_/b ,provo ar\nd ,utah ,lake #dj1jjj;,glass #g #e-c_/d ,santa ,ana ,riv] to ,los ,angeles #cc1jjj,porcela9 #f-c_/d #d-g_/h ,spi] ,falls to ,s*5ectady #cj1jjj,porcela9 #h-a_/b #f-c_/d ,apple ,riv] ,falls to ,/ ,paul #be1jjj;,glass #g #e-c_/d ,*ambly to ,montreal #be1jjj,porcela9 #e-a_/b #f-a_/b ,niag>a ,falls to ,buffalo #bb1jjj,porcela9 #g-a_/b #g ,portsm\? to ,pelham1 ,n4 ,h4 #ac1jjj,porcela9 #e-a_/d #c-c_/d ,g>v9s ,falls to ,man*e/]1 ,n4 ,h4 #ab1jjj;,glass #e #d-c_/d ---------------------------------------- ------------------------- ,! inn] petticoat or sleeve t runs d[n ov] ! p9 & sometimes rea*es ne>ly to ! cross-arm1 ( c\rse becomes wet on its outside surface & at its l[] edge dur+ a ra92 b betwe5 ?is l[] wet "p ( ! inn] petticoat1 or sleeve1 & ! l[] wet edge ( ! l>g] outside petticoat1 !re is a wide1 dry /rip ( insulator surface4 ,a result is t an arc ov] ! surface ( ! outside petticoat c rea* ! wet edge ( ! sleeve only by cross+ ! /rip ( dry "u surface or jump+ ?r\gh ! air4 ,! same type ( insulator is us$ on ! #fj1jjj-volt l9es betwe5 ,electra & ,san ,francisco & betwe5 ,colgate & ,oakl&1 ea* insulator hav+ an out] petticoat #aa in*es 9 diamet] & "o inn] petticoat or sleeve #f-a_/b in*es 9 diamet]4 ,?is inn] petticoat runs d[n ! p9 = a di/ance ( #g-a_/b in*es bel[ ! out] petticoat4 ,slightly diff]5t p9s are us$ = m\nt+ ! insulators on ! two transmission l9es j nam$1 s t on ! =m] ! di/ance ?r\gh air f ! l[] edge ( ! out] petticoat to ! cross-arm is #aa in*es1 & on ! latt] ! correspond+ di/ance is #aa-a_/b in*es4 ,on ! ,electra l9e ! l[] edge ( ! inn] petticoat ( ea* insulator is ab\t #c-a_/b in*es1 & on ! ,colgate l9e ab\t #d in*es above ! cross-arm4 ,,insulators ,,on ,,transmission ,,l9es4 ---------------------------------------- --------------------------- ,in*es ,in*es ,in*es ,in*es f f f f ,top ( ,outside ,l[e/ ,edge ( ,location ( ,l9e4 ,insulator,petticoat,petticoat ,outside to to to to ,edge ,cross- ,cross- ,cross- ( ,l[e/ arm4 arm4 arm4 ,petticoat4 ---------------------------------------- --------------------------- ,electra to ,san ,francisco #ad-a_/b #aa #c-a_/b #g-a_/b ,colgate to ,oakl& #ae #aa-a_/b #d #g-a_/b ,caon ,f]ry to ,butte #ac-a_/b #g-c_/d #a-a_/b #f-a_/d ,%aw9igan ,falls to ,montreal #af-a_/d #aa-c_/d #c-a_/d #h-a_/b ,santa ,ana ,riv] to ,los ,angeles #h-e_/h #c-c_/d #c-c_/d #j ,spi] ,falls to ,s*5ectady #aj-c_/d #g-c_/h #d-a_/d #c-c_/h ,niag>a ,falls to ,buffalo #aj #e-a_/b #c #b-a_/b ,*ambly to ,montreal #h-a_/b #d-a_/b #b #b-a_/b ---------------------------------------- --------------------------- ,on ea* ( ! l9es nam$ 9 ?is table ! wires are /rung on ! tops ( _! insulators4 ,! ,caon ,f]ry l9e is c>ri$ on insulators ea* ( :i* has ?ree %ort petticoats & a long sep>ate sleeve t runs d[n ov] ! p9 to )9 #a-a_/b in*es ( ! cross-arm4 ,?is sleeve makes contact ) its insulator ne> ! p9 hole4 ,! outside petticoat ( ea* insulator on ?is l9e is #g-c_/d in*es above ! cross-arm & #f-a_/d in*es above ! l[] end ( ! sleeve4 ,bo? ! ma9 insulator & ! sleeve1 9 ?is case1 are ( glass4 ,:ite porcela9 insulators are us$ to support ! #ej1jjj-volt ,%aw9igan l9e1 & are ( a rec5t design4 ,ea* ( ^! insulators has ?ree petticoats rang$ ab\t a c5tral /em s t _! l[] edges are #d-a_/b in*es1 #i in*es1 & #ac in*es respectively1 bel[ ! top4 ,! highe/ petticoat is #aj in*es1 ! int]m$iate #i-c_/d in*es1 & ! l[e/ #d-a_/d in*es 9 diamet]4 ,! height ( ?is insulator is #ac in*es1 comp>$ ) #aa-a_/d in*es = ^? us$ on ! ,electra & ,colgate l9es & #ab in*es = ! comb9$ insulator & sleeve us$ on ! ,caon ,f]ry l9e4 ,:5 m\nt$ on its p91 ?is insulator on ! ,%aw9igan l9e holds its wire #af-a_/d in*es above ! cross-arm1 comp>$ ) a correspond+ di/ance ( #ad-a_/b in*es on ! ,electra1 #ae in*es on ! ,colgate1 & #ac-a_/b in*es on ! ,caon ,f]ry l9e4 ,! two upp] petticoats on ea* ( ^! insulators are mu* less concave ?an ! l[e/ "o1 & ! edges ( all ?ree /& respectively #aa-c_/d1 #g-a_/d1 & #c-a_/d in*es above ! cross-arm4 ,f ! edge ( ! top to ! edge ( ! bottom petticoat ! direct di/ance is #h-a_/b in*es4 ,( ! ?ree transmission l9es above nam$ t op]ate at #ej1jjj to #fj1jjj volts1 t betwe5 ,%aw9igan ,falls & ,montreal leads z to di/ances betwe5 ! l9e wire & insulator petticoats & ! cross-arm4 ,on ! ,santa ,ana l9e1 :]e ! voltage is #cc1jjj1 ! insulator is ( a m ord9>y type1 be+ ( porcela91 #f-c_/d in*es 9 diamet]1 #d-g_/h in*es high1 & hav+ ! l[] edges ( its ?ree petticoats 9 ! same plane4 ,ea* ( ^! insulators holds its wire #h-e_/h in*es above ! cross-arm1 & has all ( its petticoats #c-a_/b in*es above ! cross-arm4 ,unlike ! ?ree insulators j describ$1 :i* are m\nt$ on wood5 p9s1 ?is ,santa ,ana insulator has a p9 ) an iron core1 wood5 ?reads1 & porcela9 base4 ,?is base ext5ds up f ! cross-arm a di/ance ( #c-a_/h in*es1 & ! wood5 sleeve1 9 :i* ! ?reads = ! insulator are cut1 runs d[n ov] ! c5tral bolt ( ! p9 to ! top ( ! porcela9 base1 :i* is #e_/h-;in* bel[ ! petticoats4 ,! #cj1jjj-volt l9es f ,spi] ,falls are c>ri$ #aj-c_/d in*es above _! cross-arms by triple petticoat porcela9 insulators4 ,ea* ( ^! insulators is #h-a_/b in*es 9 diamet]1 #f-c_/d in*es high1 & is built up ( ?ree p>ts cem5t$ toge!r4 ,a malleable-iron p9 cem5t$ into ea* insulator ) pure ,portl& cem5t c>ries ! outside petticoat #g-a_/b in*es & its l[e/ petticoat #d-a_/d in*es above ! cross-arm4 ,:5 ! voltage on ! ,spi] ,falls l9es 0 rais$ f ab\t #ac1jjj to #cj1jjj1 ! circuits be+ c>ri$ 9 "p by "o-piece porcela9 insulators1 a numb] ( ^! insulators 7 punctur$ at ! high] pressures1 & "s cross-arms & poles 7 burn$ z a result4 ,no failures result$ on ^? p>ts ( ^! l9es :]e ! ?ree-"p insulators 7 9 use4 ,! second pole l9e betwe5 ,niag>a ,falls & ,buffalo 0 design$ to c>ry circuits at #bb1jjj volts1 or twice t = :i* ! fir/ l9e 0 built4 ,porcela9 insulators 7 employ$ on bo? ( ^! l9es1 b :ile ! #aa1jjj-volt l9e 0 c>ri$ on ?ree-petticoat insulators1 ea* ) a diamet] ( #g in*es & a height ( #e-a_/b in*es1 ! #bb1jjj-volt l9e 0 m\nt$ on insulators ea* #g-a_/b in*es 9 diamet] & #g in*es high1 ) only two petticoats4 ,! old] insulator has its petticoats #b in*es above ! cross-arm1 & ! l[] petticoat ( ! new insulator is #c in*es above ! arm4 ,^! two insulators illu/rate ! t5d5cy to l5g!n out along ! insulator axis z ! voltage ( ! circuits to be c>ri$ increases4 ,illu/ration3 ,,fig4 #ic;,a4--,! ,old & ,new ,insulators on ! ,niag>a ,falls-,buffalo ,l9e4 ,= future "w at /ill high] voltages1 ! advantage z to bo? fir/ co/ & insulat+ qualities seems to lie ) insulators t are v long 9 an axial direction1 & :i* h _! petticoats arrang$ "o bel[ ! o!r & all ( ab\t ! same diamet]1 r ?an ) insulators ( ! umbrella type1 l ^? on ! ,electra & ,colgate l9es4 ,,*apt] ,,xxii4 ,,design ,,( ,,insulator ,,p9s ,,= ,,transmission ,,l9es4 ,b5d+ /ra9s due to ! weights1 degree ( t5sion1 & ! directions ( l9e wires1 plus ^? result+ f w9d-pressure1 are ! *ief causes t lead to ! me*anical failure ( insulator p9s4 ,consid]+ ! unbalanc$ compon5t ( ^! =ces at "r angles to ! axis ( ! p91 :i* alone produce b5d+1 ea* p9 may be consid]$ z a beam ( circul> cross section secur$ at "o end & load$ at ! o!r4 ,= ?is purpose ! secur$ end ( ! beam is to be tak5 z ! po9t :]e ! p9 ent]s its cross-arm1 & ! load$ end ( ! beam is ! po9t :]e ! l9e wire is atta*$ to ! insulator4 ,! di/ance betwe5 ^! two po9ts is ! l5g? ( ! beam4 ,! maximum /ra9 9 ! outside fibres ( a p9 measur$ 9 p\nds p] squ>e in* ( its cross section1 repres5t$ by ,s1 may be f\nd f ! =mula1 ,p ,x ,s ------- 4#jihb ,d :]e ,p is ! pull ( ! wire 9 p\nds1 ,d is ! diamet] ( ! p9 at any po9t1 & ,x is ! di/ance 9 in*es ( t po9t f ! wire4 ,inspection ( ?is =mula %[s t ,s1 ! maximum /ra9 at any po9t 9 ! fibres ( a p91 :5 ! pull ( ! l9e-wire1 ,p1 is con/ant1 increases directly ) ! di/ance1 ,x1 f ! wire to ! po9t :]e ! /ra91 ,s1 takes place4 ,?is /ra91 ,s1 ) a con/ant pull ( ! l9e wire1 decreases z ! cube ( ! diamet]1 ,d1 at ! po9t on ! p9 :]e ,s occurs increases4 ,t cross section ( a p9 j at ! top ( its hole 9 ! cross-arm is ?us subject to ! greate/ /ra91 if ! p9 is ( uni=m diamet]1 because ?is cross section is m di/ant f ! l9e wire ?an any o!r t is expos$ to ! b5d+ /ra94 ,= ?is reason x is n necess>y to give a p9 a uni=m diamet] above its cross-arm1 & 9 practice x is always tap]$ t[>d its top4 ,not)/&+ ?is tap]1 ! weake/ po9t 9 p9s z usually made is j at ! top ( ! cross-arm1 & x is at ?is cross section :]e p9s usually break4 ,?is break comes j bel[ ! %\ld] t is turn$ on ea* p9 to prev5t its slipp+ d[n ?r\gh ! hole 9 its cross-arm4 ,if ! %\ld] on a p9 made a tight fit all ar\nd d[n onto ! cross-arm1 ! /r5g? ( ! p9 to resi/ b5d+ w\ld be !reby increas$1 b x is h>d to be sure ( mak+ su* fits1 & !y %\ld n be reli$ on to increase ! /r5g? ( p9s4 ,by giv+ a p9 a suitable tap] f its %\ld] at ! cross-arm to its top1 ! /ra9 p] squ>e in*1 ,s1 9 ! outside fibres ( ! p9 may be made con/ant = e cross section ?r\gh\t its l5g? above ! cross-arm1 :atev] t l5g? may be4 ,! =mula above giv5 may be us$ to det]m9e ! diamet]s ( a p9 at v>i\s cross sections t w make ! maximum /ress1 ,s1 at ea* ( ^! cross sections con/ant4 ,by transposition ! =mula becomes ,p ,d ------- ,x4 4#jihb ,s ,:]e ! p9 is tap]$ s t ,s is con/ant = all cross sections1 !n = any pull1 ,p1 ( ! l9e wire on ! p9 ! quantity 7,p_/4#jihb ,s7 mu/ be con/ant at e diamet]1 ,d1 di/ant any numb] ( in*es1 ,x1 f ! po9t :]e ! wire is atta*$4 ,if ! con/ant1 7,p_/4#jihb ,s7 is f\nd = any "o cross section ( a p91 !re=e1 ! diamet] at ea* o!r cross section ) ! same maximum /ress1 ,s1 may be readily f\nd by sub/itut+ ! value ( ?is con/ant 9 ! =mula4 ,! s-call$ 8/&>d0 wood5 p9 t has be5 v g5]ally us$ = ord9>y di/ribution l9es1 & to "s ext5t ev5 on high-voltage transmission l9es1 has a diamet] ( ne>ly #a4e in*es j bel[ ! %\ld]4 ,! di/ance ( ! l9e wire above ?is %\ld] v>ies betwe5 ab\t #d4e & #f in*es1 accord+ to ! type ( insulator us$1 & to :e!r ! wire is ti$ at ! side or top ( ! insulator4 ,if ! l9e wire is ti$ to ! insulator #e in*es above ! %\ld] ( "o ( ! /&>d p9s1 !n ,x becomes #e1 & ,d becomes #a4e 9 ! =mula la/ giv54 ,f t =mula by transposition & sub/itution ,p ,d 7#a4e7 ------- --- ------ #j4fge4 4#jihb ,s ,x #e ,sub/itut+ #j4fge = ! quantity 7,p_/#j4jihb ,s7 9 ! =mula ,d 7,p_/#j4jihb ,s7 ,x gives ! =mula ,d #j4fge ,x1 f :i* ! diamet]s at all cross sections ( a tap]$ p9 above its %\ld]1 t w give x a /r5g? j equal to t ( a section ( #a4e in*es diamet] & #e in*es f ! l9e wire1 may be f\nd4 ,to use ! =mula = ?is purpose x is only necess>y to sub/itute any desir$ values ( ,x !re9 & !n solve 9 ea* case = ! correspond+ values ( ,d4 ,let x be requir$1 = in/ance1 to det]m9e :at diamet] a p9 %\ld h at a cross section "o in* bel[ ! l9e wire 9 ord] t ! maximum /ra9 at t cross section may equal ! correspond+ /ra9 at a cross section five in*es bel[ ! l9e wire & ( #a4e in* diamet]4 ,sub/itut+ "o z ! value ( ,x1 ! la/-nam$ =mula becomes ,d #j4fge1 & f ?is1 ,d #j4hgg1 :i* %[s t ! diamet] ( ! p9 "o in* bel[ ! l9e wire %\ld be #j4hgg-;in*4 ,a simil> calculation w %[ t if a p9 is long en\gh s t a cross section above ! cross-arm is #ab in*es bel[ ! l9e wire1 ! diamet] ( ?is cross section %\ld be equal to ! cube root ( #j4fge #ab #h4a1 :i* is #b4jjh1 or practically two in*es4 ,x %\ld be obs]v$ t ! calculations j made h no?+ to d ) ! ability ( a p9 to resi/ any p>ticul> pull ( its l9e wire4 ,^! calculations simply %[ :at diamet]s a p9 %\ld h at diff]5t di/ances bel[ its l9e wire 9 ord] t ! maximum /ress at ea* ( its cross sections may equal t at a cross section #e in*es bel[ ! wire :]e ! diamet] is #a4e in*es4 ,9 ,vol4 xx41 ,a4 ,i4 ,e4 ,e41 pp4 #dae to #dai1 specifications are propos$ = /&>d insulator p9s bas$ on calculations l ^? j made4 ,z a result ( su* calculations1 ! foll[+ table = ! correspond+ values ( ,x & ,d1 z us$ 9 ! above =mula1 are !re pres5t$1 ea* express$ 9 in*es4 ---------- ,x ,d ---------- #a #j4hgg #b #a4ajf #c #a4bfc #d #a4cie #e #a4ejj #f #a4eib #g #a4fgh #h #a4ged #i #a4hbe #aj #a4hhh #aa #a4ie #ac #b4jf #ae #b4ag #ag #b4be #ai #b4cd #ba #b4db ---------- ,a p9 tw5ty-"o in*es long betwe5 ! l9e wire & ! cross-arm w h a uni=m /r5g? to resi/ ! pull ( ! wire if x has ! diamet] giv5 9 ?is table at ! correspond+ di/ances bel[ ! l9e wire4 ,f ?is x foll[s t a p9 ( any l5g? betwe5 wire & cross-arm correspond+ to ,x 9 ! table w be equally /rong to resi/ a pull ( ! l9e wire z a /&>d #a4e-;in* diamet] p9 ) its wire five in*es above ! cross-arm4 ,9 o!r words1 if a p9 t is tw5ty-"o in*es long betwe5 ! l9e wire & ! cross-arm has ! diamet]s giv5 9 ! table at ! correspond+ di/ances bel[ ! wire1 !n a p9 ( equal /r5g? to resi/ b5d+1 & ( any %ort] l5g?1 w\ld correspond 9 ! "p above ! cross-arm to an equal l5g? cut f ! top end ( ! long] p94 ,designat+ t "p ( a p9 t is above ! cross-arm z ! 8/em10 & t "p 9 ! cross-arm z ! 8%ank10 ea* p9 9 ! specifications "u consid]ation is nam$ by ! l5g? ( its /em1 z a #e-1 #g- or #aa-;in* p94 ,x is propos$ t ea* p9 ( :atev] l5g? be ?read$ = a di/ance ( #b4e in*es at ! top ( its /em ) f\r ?reads p] in*1 ! sides ( ea* ?read be+ at an angle ( n9ety degrees ) ea* o!r4 ,ea* ?read is to cut into ! p9 ab\t #c_/cb in*1 come to a %>p angle at ! bottom1 & be ab\t #a_/af in* wide on top4 ,at ! end ( ! p9 ! propos$ diamet] ov] ! ?read is "o in* 9 all cases1 & at ! l[] end ( ! ?read$ portion ! outside diamet] is #a4be in*es4 ,ne> ! end ( ! p9 ! diamet] at ! bottom ( ! ?read is ?us only #ac_/af in*1 & ! correspond+ diamet] at ! l[] end ( ! ?read$ portion is ab\t #a-a_/af in*es on all p9s4 ,ea* p9 is to h a squ>e %\ld] to re/ on ! cross-arm1 & ! diamet] ( ?is %\ld] is to be #c_/h in* great] ?an ! nom9al diamet] ( ! %ank ( ! p94 ,! propos$ l5g? ( ?is %\ld] on all p9s is #a_/d in* be=e ! tap] beg9s4 ,! actual diamet] ( ! %ank ( ea* p9 j bel[ its %\ld] is to be #a_/cb in* less ?an ! nom9al diamet]1 & ! actual diamet] ( ! l[] end ( ea* %ank is to be #a_/af in* less ?an ! nom9al diamet]4 ,) ^! explanations ! propos$ sizes ( p9s h dim5sions z foll[s 9 in*es3 ----------------------------- ,nom9al ,l5g? (,l5g? (,diamet] ( ,/em4 ,%ank4 ,%ank4 ----------------------------- #e #d-a_/d #a-a_/b #g #d-a_/d #a-c_/d #i #d-a_/d #a-g_/h #aa #d-c_/d #b #ac #d-c_/d #b-a_/h #ae #d-c_/d #b-a_/d #ag #e-c_/d #b-c_/h #ai #e-c_/d #b-a_/b ----------------------------- ,9 ord] rightly to appreciate ! utility ( ?is table ( propos$ /&>d p9s1 x is necess>y to h 9 m9d ! fact t all ! dim5sions are bas$ on ! assumption t a wood5 p9 ) a %ank ( "o & "o-half in*es diamet]1 & ) its l9e wire atta*$ five in*es above ! cross-arm1 is /rong en\gh = g5]al use on transmission l9es4 ,su* an assumption cov]s a wide range ( practice1 b its tru? may well be d\bt$ = _m cases4 ,t ?is assumption does =m ! basis ( ! entire table is cle>ly %[n by ! fact t ! calculat$ diamet] at ! %ank ( ea* p9 is made to dep5d on a uni=m pull1 ,p1 ( ! l9e wire1 giv+ a uni=m maximum /ress1 ,s1 9 ! out] fibres ( ! wood j :]e ! %ank jo9s ! /em4 ,9 o!r words1 e p9 9 ! table is design$ to break ) a uni=m pull ( ! l9e wire1 provid$ t ! po9t on ! insulator :]e ! wire is atta*$ is j on a level ) ! top ( its p9 9 ea* case4 ,x w at once occur to practical m5 t :ile a five-in* p9 ) "o & "o-half in* %ank1 or a l>g] p9 ( equal ability to resi/ ! pull ( a l9e wire1 may be /rong en\gh = ! conductors ( "s transmission l9es1 ?is same p9 may be entirely too weak = ! long] spans1 %>p] angles1 & heavi] conductors ( o!r l9es4 ,?us1 on ! sixty-five-mile l9e betwe5 ,caon ,f]ry & ,butte1 ,mont41 ea* conductor is ( copp] & has a cross section ( #ajf1ejj cm41 :ile on ! old] l9e betwe5 ,niag>a ,falls & ,buffalo ea* copp] conductor has a cross section ( #cej1jjj cm4 ,evid5tly ) equal conditions z to l5g? ( span1 am\nt ( sag1 & %>pness ( angles on ^! two l9es1 p9s ample 9 /r5g? = ! small] wire might be mu* too weak = ! l>g] wire4 ,a little consid]ation w %[ t x is nei!r rational nor desirable to adopt p9s ( uni=m /r5g? = all transmission l9es1 b t sev]al degrees ( /r5g? are necess>y to correspond ) ! range 9 sizes ( conductors 9 regul> use4 ,! size ( p9s = use on any transmission l9e1 :5 ! maximum b5d+ /ra9 ex]t$ by ! conductors has be5 det]m9$1 %\ld be f\nd by calculation & exp]im5t1 or by exp]im5t alone4 ,accord+ to ,trautw9e1 ! av]age compressive /r5g? ( yell[ locu/ is #i1hjj p\nds1 ( hickory #h1jjj p\nds1 & ( :ite oak #g1jjj p\nds p] squ>e in* 9 ! direction ( ! gra94 ,^! compressive /r5g?s are less ?an ! t5sile /r5g?s ( ! same woods1 & %\ld !re=e be employ$ 9 calculation1 s9ce ! fibres on "o side ( a b5d+ p9 are compress$ :ile ! fibres on ! o!r side are elongat$4 ,sub/itut+ #a1jjj = ! value ( ,s 9 ! =mula1 ,s 7,p ,x_/74#jihb ,d771 & also #e = ! value ( ,x1 & #a-a_/b = ! value ( ,d1 ! result+ value ( ,p is f\nd to be #gcf4e p\nds4 ,?is result %[s t ) a locu/ p9 ( #a-a_/b in*es diamet] at ! %ank1 & ) its l9e wire atta*$ five in*es above ! %\ld]1 ! unbalanc$ side pull ( ! wire t w break ! p9 by b5d+ is #gcf p\nds1 provid$ t ! wood ( ! p9 has a /r5g? ( #a1jjj p\nds p] squ>e in* 9 compression4 ,z all ( ! propos$ /&>d p9s 9 ! above table are design$ = uni=m /r5g? to resi/ ! same pull ( a l9e wire atta*$ on a level ) ! top ( ! p9 9 ea* case1 x foll[s t ! pull ( #gcf p\nds by ! wire w break any "o ( ^! p9s "u ! conditions /at$4 ,! calculation j made takes no acc\nt ( ! fact t ! actual diamet] ( ! %ank ( ea* p9 j bel[ ! %\ld] is #a_/cb in* less ?an ! nom9al diamet]1 b ?is ( c\rse r$uces ! /r5g? some:at4 ,trautw9e /ates t ! figures above giv5 = ! compressive /r5g?s ( wood are only av]ages & are subject to mu* v>iation4 ,( c\rse no p9 %\ld be kn[+ly load$ 9 regul> practice to ! break+ po9t1 & to provide aga9/ v>iations 9 ! /r5g? ( wood1 & = unexpect$ /ra9s1 a lib]al factor ( safety1 say f\r1 %\ld be adopt$ 9 fix+ ! maximum /ra9s on insulator p9s4 ,apply+ ?is factor to ! calculations j made1 x appe>s t ! maximum pull ( ! l9e wire at ! top ( any "o ( ! above propos$ /&>d p9s %\ld n exce$ #gcf #d #ahd p\nds 9 regul> "w4 ,a little calculation w readily %[ t ! side pull ( "s ( ! l>g] conductors n[ 9 use on transmission l9es w greatly exce$ #ahd p\nds "u conditions1 z to sag1 angles & w9d pressure1 t are frequ5tly met 9 practice4 ,on page #ddh1 ,vol4 xx41 ,a4 ,i4 ,e4 ,e41 "s te/s are report$ on six locu/ wood p9s ) %ank diamet]s ( #a-g_/af to #a-a_/b in*es4 ,ea* ( ^! p9s 0 te/$ by ins]t+ its %ank 9 a hole ( #a-a_/b in*es diamet] 9 a block ( h>d wood1 & !n apply+ a /ra9 at ab\t "r angles to ! p9 & ab\t #d-a_/b in*es f ! block by means ( a ,sell]'s ma*9e4 ,! pull on ea* p9 0 appli$ gradually1 & 9 mo/ ( ! p9s ! fibres ( ! wood began to "p :5 ! side pull rea*$ #gjj to #gej p\nds1 ?\gh ! maximum loads su/a9$ 7 ab\t t5 p] c5t above ^! figures4 ,! av]age calculat$ value ( ,s1 ! compressive /r5g? ( ! wood 9 ^! p9s1 0 #aa1acj p\nds p] squ>e in* on ! basis ( ! loads at :i* ! fibres ( ! wood began to break1 & #ac1fbc p\nds p] squ>e in* = ! loads at :i* ! p9s gave way4 ,on pages #fej to #fec ( ! volume la/ cit$1 results are report$ ( te/s on tw5ty-two p9s ( eucalyptus wood1 :i* is g5]ally us$ = ?is purpose 9 ,cali=nia4 ,twelve ( ^! p9s 7 ( a size mu* us$ 9 ,cali=nia on l9es :]e ! voltage is n above #cj1jjj4 ,ea* ( ! twelve p9s 0 #f-g_/h in*es long 9 ! /em1 #d-e_/h in*es long 9 ! %ank1 #a-a_/b in*es 9 diamet] at ! %ank1 #b in*es 9 diamet] at ! squ>e %\ld] :]e ! %ank jo9s ! /em1 & #a-c_/h in*es 9 diamet] at ! top ( ! ?read4 ,! p9s 7 te/$ by m\nt+ ea* ( !m 9 a cross-arm1 secur+ ! cross-arm 9 a te/+ ma*9e s t ! p9 0 horizontal1 plac+ an insulator on ! p91 & ex]t+ ! /ra9 on a cable wrapp$ ar\nd ! side groove ( ! insulator4 ,?is cable v>i$ a little f "r angles to ! axis ( ea* p91 b ! compon5t ( ! /ra9 at "r angles to ?is axis 0 calculat$ & ! break+ load "h m5tion$ is t compon5t4 ,ne>ly all ( ^! twelve p9s broke squ>e (f at ! cross-arm4 ,= a s+le p91 ! l[e/ break+ /ra9 0 #gje p\nds1 ! l>ge/ #a1cfj p\nds1 & ! av]age = ! twelve p9s 0 #a1jhe p\nds4 ,un=tunately1 ! exact di/ance ( ! cable f ! cross-arm is n /at$1 b z ! cable 0 w\nd ab\t ! side groove ( ! insulator x 0 probably ei!r 9 l9e ) or a little bel[ ! top ( ! p94 ,x seems probable also t ! diamet] ( ^! p9s at ! %\ld]--t is1 two in*es--may h increas$ ! break+ /ra9 some:at by giv+ ! %\ld] a good be>+ on ! cross-arm4 ,! t5 o!r p9s 7 ( ! size 9 use on ! #fj1jjj-volt l9e betwe5 ,colgate p[]-h\se & ,oakl&1 ,cal4 ,ea* ( ^! p9s _h a l5g? ( #e-c_/h in*es & a maximum diamet] ( #b-a_/h in*es 9 ! %ank1 & a l5g? ( #aj-c_/h in*es 9 ! /em1 ) a diamet] ( #b-a_/b in*es at ! %\ld]4 ,?is %\ld] 0 n squ>e1 b its surface =m$ an angle ( =ty-five degrees ) ! axis ( ! p91 & ?is bevel %\ld] took up #a_/d in* ( ! l5g? j giv5 = ! /em ( ! p94 ,at #b-a_/b in*es f its ?read$ end ! /em ( ! p9 _h a diamet] ( #a-ae_/af in*es1 & ! diamet] slopes to #a-c_/h in*es at two in*es f ! end4 ,! two in*es ( l5g? at ! top ( ! /em has ! uni=m diamet] ( #a-c_/h in*es1 & is ?read$ ) f\r ?reads p] in* = ! insulator4 ,ea* ( ^! t5 p9s 0 te/$1 z already describ$1 until x broke1 b ! break 9 ?is case />t$ z a split at ! l[] end ( ! ?read$ portion & ran d[n ! /em to ! %\ld] 9 a l9e ne>ly p>allel ) ! axis ( ! p94 ,! pull on ! cable at "r angles to ! axis ( ea* p9 _h a maximum value ( #a1dge p\nds 9 "o case1 & a correspond+ value ( #c1aij p\nds 9 ano!r1 :ile ! av]age break+ /ra9 = ! t5 p9s 0 #b1caj p\nds4 ,un=tunately1 ! report ( ?is te/ above nam$ does n di/9ctly /ate j h[ f> ! te/+ cable 0 atta*$ above ! %ank ( ea* ( ^! l>ge p9s2 b x seems probable t ! same insulator 0 us$ ) ! l>g] z ) ! small] p9s1 & if ?is 0 s ! te/+ cable 0 atta*$ ne> ! end ( ea* p91 z ?is cable 0 w\nd ab\t ! side groove ( ! insulator us$ on ! small] p9s4 ,) ! types ( insulator 9 actual use on ! ,colgate & ,oakl& l9e ! wire is c>ri$ at ! top groove & its c5tre is ab\t two & a half in*es above ! top ( ! p94 ,x is !re=e probable t ^! p9s w\ld n )/& z great /ra9s on ! l9es z !y did 9 ^! te/s4 ,! bevel %\ld] on ea* ( ^! l>g] p9s no d\bt increases its ability to resi/ a b5d+ /ra91 because ! bevel surface fits tightly d[n into a c\nt]bore 9 ! cross-arm4 ,:]e ! p9 has a %\ld] at "r angles ) ! axis1 z is m usually ! case1 & ! top ( ! cross-arm is a little r\nd+1 ! squ>e %\ld] does n h a firm seat & is ( slight importance z f> z ! /r5g? ( ! p9 to resi/ a b5d+ /ra9 is conc]n$4 ,evid5tly ! weake/ po9t 9 ! t5 l>g] p9s ( ?is te/ 0 at ! l[] end ( ! ?read$ portion1 s9ce 9 ea* case ! break 0 9 ! =m ( a long split />t+ :]e ! ?read end$4 ,!re seems to be no suffici5t reason = ! r$uction ( ! diamet] ( a p9 int5d$ = a heavy l9e wire to a diamet] z small z "o in* at ! ?read$ end1 or = limit+ ! l5g? ( ! ?read$ portion to #b4e in*es1 z propos$ 9 ! specifications = /&>d p9s4 ,x is c]ta9 t ! co/ ( ! p9 w\ld be no m if its diamet] at ! ?read$ end 7 #a-a_/d or #a-c_/h in*es ) a uni=m tap] f ! end ( ! p9 d[n to ! %\ld] & ) ! ?read cut d[n ! /em = ?ree or f\r in*es4 ,fur!rmore1 any increase 9 ! co/ ( insulators = ^! l>g] ?read$ ends ( p9s w\ld no d\bt be a small matt]4 ,"s excess ( /r5g? 9 ! /em ( a p9 ov] t ( its %ank is to be desir$1 = ! /em is m expos$ to ! wea!r & to *>r+ by leakage curr5ts ov] ! surface ( ! insulator4 ,on high-voltage l9es1 ?is *>r+ is usually worse at t "p ( ea* p9 j bel[ its ?read1 & ! commone/ breaks ( p9s on ^! l9es leave ! insulators ) ! ?read$ portions ( _! p9s hang+ on ! wire1 :ile ! rema9d] ( ea* p9 rema9s on ! cross-arm4 ,f ! te/s j not$ x is evid5tly poor design to give ! ?read$ portion ( a p9 a %ort l5g? ( uni=m diamet]1 & !n to increase ! diamet] at once by a %\ld]1 z 0 done ) ! p9s on ! ,colgate & ,oakl& l9e4 ,?is design evid5tly leads to failure ( p9s by splitt+ f ! l[] end ( ! ?reads4 ,! bett] design is ! m common "o :i* gives ! /em ( ! p9 a uni=m tap] f ! %\ld] to ! top4 ,:]e ! l9e wire is secur$ to ! top ( its insulator1 any:]e f "o to ?ree in*es above ! top ( ! p91 !re is a /rong t5d5cy = ! insulator to tip on its p91 & ?is t5d5cy is m effectively met ! long] ! jo9t betwe5 ! p9 & insulator4 ,,*apt] ,,xxiii4 ,,/eel ,,t[]s4 ,/eel t[]s are rapidly com+ into use = ! support ( electric transmission l9es t deliv] l>ge units ( en]gy at high voltages to long di/ances f wat]-p[]s4 ,"o case ( ?is sort is ! sev5ty-five-mile transmission ( #bd1jjj horse-p[] at #fj1jjj volts f ,niag>a ,falls to ,toronto4 ,ano!r example may be se5 9 ! sev5ty-five-mile l9e ( /eel t[]s :i* c>ries transmission circuits ( #fj1jjj volts to ,w9nipeg4 ,guanajuato1 ,mexico1 :i* is said to h produc$ m silv] ?an any o!r city 9 ! _w1 receives "s #c1cjj electric horse-p[] ov] a #fj1jjj-volt transmission l9e "o hundr$ miles long on /eel t[]s4 ,betwe5 ,niag>a ,falls & ,lockport ! electric circuits n[ be+ erect$ are support$ on /eel t[]s4 ,on a transmission l9e eighty miles long 9 nor!rn ,new ,york1 = :i* plans are n[ be+ made1 /eel t[]s are to support electric conductors t c>ry curr5t at #fj1jjj volts4 ,= ! elevations above gr\nd at :i* x is common to support ! conductors ( transmission l9es--t is1 f tw5ty-five to fifty feet--a /eel t[] w co/ f five to tw5ty times z mu* z a wood5 pole 9 v>i\s p>ts ( ! ,unit$ ,/ates & ,canada4 ,x foll[s at once f ?is fact t !re mu/ be cog5t reasons1 ap>t f ! matt] ( fir/ co/1 if ! g5]al sub/itution ( /eel t[]s = wood5 poles on transmission l9es is to be ju/ifi$ on economic gr\nds4 ,dur+ fifte5 ye>s ! electric transmission ( en]gy f di/ant wat]-p[]s to important c5tres ( population has gr[n f ! mo/ humble beg9n+s to ! deliv]y ( hundr$s ( ?\s&s ( horse-p[] 9 ! s]vice ( millions ( p1 & ! l9es = ?is "w are support$1 ) v few exceptions1 on wood5 poles4 ,among ! transmissions ( l>ge p[]s ov] long di/ances at v high voltages t h be5 9 successful op]ation dur+ at lea/ sev]al ye>s ) wood5 pole l9es are ! foll[+3 ! #fj1jjj-volt circuit t transmits "s #ac1jjj horse-p[] f ,electra /ation across ! ,/ate ( ,cali=nia to ,san ,francisco1 a di/ance ( #adg miles1 is support$ by wood5 poles4 ,9 ! same ,/ate1 ! transmission l9e #adb miles long betwe5 ,colgate p[]-h\se & ,oakl&1 at #fj1jjj volts1 & ) a capacity ( ab\t #ae1jjj horse-p[]1 hangs on wood5 poles1 save at ! span ne>ly a mile long ov] ! ,/raits ( ,c>qu9ez4 ,wood is us$ to c>ry ! two #ee1jjj-volt circuits t run sixty-five miles f ! #aj1jjj-;horse-p[] /ation at ,caon ,f]ry on ! ,miss\ri ,riv] to ,butte4 ,betwe5 ,%aw9igan ,falls & ,montreal1 a di/ance ( eighty-?ree miles1 ! conductors t op]ate at ab\t #ej1jjj volts are c>ri$ on wood5 poles4 ,electrical supply 9 ,buffalo to ! am\nt ( #cj1jjj horse-p[] dep5ds entirely on circuits f ,niag>a ,falls t op]ate at #bb1jjj volts & are support$ on l9es ( wood5 poles4 ,9 ! op]ation ( ^! & _m o!r high-voltage transmissions dur+ v>i\s p>ts ( ! pa/ decade "s difficulties h be5 met )1 b !y h n be5 s s]i\s z to prev5t satisfactory s]vice4 ,nev]!less1 x is n[ be+ urg$ t c]ta9 imp$im5ts t are met 9 ! op]ation ( transmission sy/ems w\ld be mu* r$uc$ by ! sub/itution ( /eel t[]s = wood5 poles1 & x is ev5 sugge/$ t p]haps ! fir/ co/1 & probably ! la/ co/1 ( a transmission l9e w\ld be less ) /eel ?an ) wood = supports4 ,! argum5t = /eel 9 ! matt] ( co/s is t :ile a t[] requires a l>g] inve/m5t ?an a pole1 yet ! small] numb] ( t[]s z comp>$ ) t ( poles may r$uce ! entire outlay = ! =m] to ab\t t = ! latt]4 ,m ?an ?is1 x is said t ! l[] depreciation & ma9t5ance *>ges on /eel supports w make _! f9al co/ no great] ?an t ( wood5 poles4 ,9 ! pres5t /ate ( ! m>ket1 /eel t[]s c be _h at f ?ree to ?ree & "o-half c5ts p] p\nd1 & ! co/ ( a /eel t[] or pole w v>y ne>ly z its weight4 ,dur+ ! fir/ half ( #aijd ! quotations on tubul> /eel poles to ! ,s\?side ,suburban ,railway ,company1 ( ,*icago1 7 betwe5 ! limits j /at$4 ,t company ord]$ "s poles built up ( /eel sections ab\t t "t at a trifle less ?an ?ree c5ts p] p\nd4 ,ea* ( ^! poles 0 ?irty feet long & weigh$ #faf p\nds1 s t its co/ 0 ab\t eighte5 doll>s 7xxi1 ,a4 ,i4 ,e4 ,e41 #ged74 ,= a =ty-five-foot /eel pole to c>ry a pair ( #aa1jjj-volt1 ?ree-phase circuits along ! ,new ,york ,c5tral electric road ! e/imat$ co/ 0 eighty doll>s 9 ! ye> la/ nam$ 7xxi1 ,a4 ,i4 ,e4 ,e41 #gec74 ,on ! #ajj-mile l9e to ,guanajuato1 ,mexico1 above m5tion$1 ! /eel t[]s 7 built up ( #c #c #c_/af angles = legs1 & 7 /ay$ ) small] angle sections & rods4 ,ea* ( ^! t[]s has f\r legs t come toge!r ne> ! top1 is =ty feet high1 weighs ab\t #a1ejj p\nds1 & c>ries a s+le circuit compos$ ( ?ree ,no4 #a ,b4 ,s4 gauge h>d-drawn copp] cables4 ,! weight ( ea* ( ^! cables is #a1cdj p\nds p] mile1 & ! =ty-foot t[]s are spac$ #ddj feet ap>t1 or twelve p] mile1 ov] ne>ly ! entire l5g? ( l9e4 ,at ?ree c5ts p] p\nd1 ! l[e/ figure at :i* ^! t[]s c\ld probably be secur$ = use 9 ! ,unit$ ,/ates1 ! approximate co/ ( ea* w\ld be =ty-five doll>s4 ,betwe5 ,niag>a ,falls & ,lockport ea* ( ! /eel t[]s t is to c>ry a s+le ?ree-phase transmission circuit has ?ree legs built up ( tub+ t tap]s f two & "o-half in*es to small] sizes & is brac$ at frequ5t int]vals4 ,! height ( ^! t[]s is =ty-n9e feet1 & ! weight ( ea* is #b1hjj p\nds4 ,at ?ree c5ts p] p\nd ! co/ ( ea* t[] am\nts to eighty-f\r doll>s4 ,= a long transmission l9e 9 nor!rn ,new ,york bids 7 rec5tly _h on t[]s =ty-five feet high to c>ry six wires1 & ! result+ prices 7 #ajj to #abe ea* = a t[] weigh+ ab\t #c1jjj p\nds4 ,on ! l9e betwe5 ,niag>a ,falls & ,toronto ! /&>d t[] holds ! l[e/ cables #dj feet above gr\nd at ! insulators1 has a weight ( #b1cfj p\nds1 & w\ld co/ #gj4hj at #c c5ts p] p\nd4 ,9 ,janu>y1 #aijb1 f\r /eel t[]s 7 pur*as$ to support transmission circuits = two spans ( #acb feet ea* ov] ! ,*ambly ,canal1 ne> ,*ambly ,canton1 ,quebec4 ,ea* pair ( ^! t[]s 0 requir$ to support elev5 ,no4 #b-j ,b4 ,s4 gauge b>e copp] wires ) ! span ( #acb feet betwe5 !m4 ,! v]tical height ( ea* ( ^! f\r t[]s is #add feet above ! f\ndation1 & !y 7 design$ = a maximum /ress 9 any memb] ( n m ?an "o-f\r? ( its ultimate /r5g?1 ) wires coat$ to a diamet] ( "o in* ) ice & "u w9d pressure4 ,= ^! f\r /eel t[]s erect$ on f\ndations suppli$ by ! pur*as]s ! price 0 #d1fgj1 & ! contract call$ = a weight 9 ! f\r t[]s ( n less ?an #aba1jjj p\nds4 ,on ! basis ( ?is weight ! co/ ( ! t[]s erect$ on f\ndations 0 #c4hf c5ts p] p\nd4 ,) ^! examples ( ! co/ ( /eel t[]s a fair idea may be gott5 ( ! relative co/ ( wood5 poles4 ,= poles ( c$> or o!r desirable wood ?irty-five feet long & ) eight-in* tops fitt$ ) ei!r "o or two cross-arms an e/imat$ co/ ( five doll>s ea* is ample to cov] deliv]y at railway po9ts ov] a great "p ( ! ,unit$ ,/ates & ,canada4 ,?is size ( pole has be5 mu* us$ on ! long1 high-voltage transmission sy/ems t involve l>ge p[] units & use heavy conductors4 ,examples ( l9es :]e su* poles are us$ may be se5 betwe5 ,niag>a ,falls & ,buffalo1 betwe5 ,colgate p[]-h\se & ,oakl&1 & betwe5 ,caon ,f]ry & ,butte4 ,( c\rse "s long] poles 7 us$ 9 special locations1 l ! cross+ ( /eam railways1 b x is also true t on ! l9es support$ by /eel t[]s su* locations make exceptionally high t[]s necess>y4 ,! ?irty-five-foot poles w hold ! electric l9es ab\t z high above ! gr\nd level z ! =ty-n9e-foot t[]s on ! ,niag>a ,falls & ,toronto transmission1 because ! =m] w be set s mu* clos] toge!r4 ,on ! l9e j nam$ ! regul> m9imum di/ance ( ! electric cables above ! gr\nd level at ! c5tres ( spans is tw5ty-five feet4 ,! /&>d t[]s on ?is l9e c>ry ! l[] electric cables =ty feet above ! gr\nd at ! insulators1 & x 0 ?\ght desirable to all[ a sag ( fifte5 feet at ! c5tres ( ! regul> spans ( f\r hundr$ feet ea*4 ,on ^! t[]s ! conductors t =m ea* ?ree-phase circuit are six feet ap>t1 & l9es drawn betwe5 ! ?ree cables =m ! sides ( an equilat]al triangle4 ,) a p9 f\rte5 & ?ree-f\r?s in*es long l t us$ on ^! /eel t[]s1 & "o conductor at ! top ( a ?irty-five-foot pole1 :]e ! o!r two are support$ by a cross-arm five feet ?ree in*es bel[1 giv+ six feet betwe5 cables1 ! l[] cables are held by _! insulators tw5ty-six feet above ! gr\nd1 :5 ! poles are set five feet deep4 ,betwe5 ?irty-five-foot poles "o hundr$ feet is a v mod]ate span1 & "o t is exce$$ 9 a numb] ( in/ances4 ,?us on ! #adb-mile l9e f ,colgate p[]-h\se to ,oakl& ! ?irty-five-foot poles are #acb feet ap>t1 & "o l9e ( ^! poles c>ries ?ree conductors ( #acc1jjj-;circul>-mil copp]1 :ile ! o!r pole l9e has ?ree alum9um cables ( #afh1jjj circul> mils4 ,on ! lat] transmission l9e f ,niag>a ,falls to ,buffalo1 :i* 0 design$ = ?ree-phase circuits ( #ejj1jjj-;circul>-mil cable1 ! regul> di/ance betwe5 ! ?irty-five-foot poles is #adj feet4 ,a maximum sag ( tw5ty-f\r in*es betwe5 poles #ajj feet ap>t "u ! conditions nam$ above br+s ! l[e/ po9ts ( ! wire tw5ty-f\r feet above ! gr\nd4 ,! /eel t[]s on ! l9e to ,guanajuato be+ only =ty feet 9 l5g?1 & spac$ #ddj feet ap>t1 x seems t ! di/ance ( conductors f ! gr\nd at ! c5tres ( spans is probably no great] ?an t j nam$4 ,p>ticul> att5tion is call$ to ?is po9t because x has be5 sugge/$ t ! use ( /eel t[]s w\ld c>ry cables s high t wires & /icks c\ld n be ?r[n onto !m4 ,x ?us appe>s t ?irty-five-foot wood5 poles set "o hundr$ feet ap>t w all[ z mu* di/ance betwe5 conductors1 & /ill keep _! l[e/ po9ts z f> above ! gr\nd1 z w =ty- to =ty-n9e-foot t[]s plac$ f\r hundr$ feet or m ap>t4 ,! two l9es t h _! conductors fur!r ap>t p]haps ?an any o!rs 9 ! _w are ! "o f ,caon ,f]ry to ,butte1 on ?irty-five-foot wood5 poles1 & ! "o to ,guanajuato1 on /eel t[]s4 ,9 ea* ( ^! cases ! cables are sev5ty-eight in*es ap>t at ! corn]s ( an equilat]al triangle4 ,) /eel t[]s f\r hundr$ feet or wood5 poles "o hundr$ feet ap>t1 f\r ( ! latt] mu/ be us$ to "o ( ! =m]4 ,at #e p] pole ?is requires an inve/m5t ( #bj 9 poles z comp>$ ) at lea/ #de = a t[] l ^? on ! ,guanajuato l9e1 #hd = a t[] l ^? on ! l9e f ,niag>a ,falls to ,lockport1 or #gj = "o ( ! t[]s on ! ,niag>a & ,toronto l9e4 ,ea* ( ! t[]s on ! l9e to ,toronto c>ries two ?ree-phase circuits1 & ! lea/ di/ance betwe5 cables is six feet4 ,to rea* ! same result z to ! di/ance betwe5 conductors ) ! two circuits on poles1 x w\ld be desirable to h two pole l9es1 s t #dj w\ld repres5t ! inve/m5t 9 ! poles to displace "o t[] = two circuits4 ,! old] pole l9e betwe5 ,niag>a ,falls & ,buffalo c>ries two ?ree-phase circuits on two cross-arms1 & ! #cej1jjj-;circul>-mil copp] cables ( ea* circuit are at ! angles ( an equilat]al triangle ^: sides are ea* ?ree feet long4 ,9 ?is case1 h[ev]1 ! electric pressure is only #bb1jjj volts4 ,! co/s above nam$ = poles & t[]s include no?+ = erection4 ,ea* t[] has at lea/ ?ree legs & m commonly f\r1 & ow+ to ! heights ( t[]s & to ! long spans !y support x is ! usual practice to give ea* leg a foot+ ( cem5t concrete4 ,x ?us seems t ! numb] ( holes to be dug = a l9e ( t[]s is ne>ly or q z great z t = a l9e ( poles1 & consid]+ ! concrete foot+s ! co/ ( erect+ ! t[]s is probably great] ?an t = ! poles4 ,) wood5 poles ab\t f\r times z _m p9s & insulators are requir$ z ) /eel t[]s1 or say twelve p9s & insulators on poles in/ead ( ?ree on a t[]4 ,= circuits ( #ej1jjj to #fj1jjj volts ! approximate co/ ( ea* insulator ) a /eel p9 may be tak5 at #a4ej1 s t ! sav+ p] t[] rea*es n m ?an #ac4ej 9 ?is respect4 ,9 ! labor ( erect+ circuits !re may be a small advantage 9 favor ( ! t[]s1 b ! weight ( ! long spans probably (fsets to a l>ge ext5t any gra9 ( "t due to few] po9ts ( support4 ,an approximate conclusion f ! above facts seems to be t a l9e ( /eel t[]s w probably co/ f #a4e to twice z mu* z a l9e or l9es ( wood5 poles to support ! same numb] ( conductors ! same di/ance ap>t1 ev5 :5 ! sav+ ( p9s & insulators is cr$it$ to ! t[]s4 ,?is conclusion applies to con/ruction ov] a l>ge "p ( ! ,unit$ ,/ates & ,canada4 ,x is kn[n t wood5 poles ( good quality reta9 en\gh /r5g? to make !m reliable z supports dur+ t5 or fifte5 ye>s1 & x is d\btful :e!r /eel t[]s w %[ en\gh long] life to m ?an (fset _! great] fir/ co/4 ,x may be not$ "h t any sav+ 9 ! co/ ( insulators or o!r advantage t !re may be 9 spans f\r hundr$ feet or m long c be z readily secur$ ) wood5 z ) /eel supports4 ,) ^! long spans ! requirem5ts are great] height & /r5g? 9 ! l9e supports1 & ^! c readily be obta9$ 9 /ructures ea* ( :i* is =m$ ( ?ree or f\r poles ) cross-braces4 ,su* wood5 /ructures h long be5 9 use at c]ta9 po9ts on transmission l9es :]e special long spans 7 necess>y or :]e !re 7 l>ge angul> *anges ( direction4 ,9 ^? special cases :]e /ructures #ge to #aej or m feet 9 height are necess>y to c>ry a span across a wat]way1 z at ! ,*ambly ,canal above m5tion$1 /eel is g5]ally m desirable ?an wood because poles ( su* l5g?s are n readily obta9able4 ,nei!r pres5t proposals nor practice1 h[ev]1 contemplates ! use ( /eel t[]s hav+ a l5g? ( m ?an =ty to fifty feet on regul> spans4 ,mu* ! /ronge/ argum5t 9 favor ( /eel t[]s = transmission l9es is t ^! t[]s give a great] reliability ( op]ation ?an d wood5 poles4 ,x is said t t[]s w act z lightn+-rods & ?us protect l9e conductors & /ation app>atus4 ,z to /atic & inductive influ5ces f lightn+1 x is evid5t t /eel t[]s c give no protection4 ,if ea* t[] has an especial gr\nd connection x w probably protect ! l9e to "s ext5t aga9/ direct lightn+ /rokes1 b !re is no reason to ?9k t ?is protection w be any great] ?an t giv5 by well-gr\nd$ gu>d wires1 or ev5 by a wire run f a gr\nd plate to ! top ( ea* pole or wood5 t[]4 ,if a direct lightn+ /roke passes f ! l9e conductors to a wood5 support x frequ5tly breaks ! insulator on t support1 & ! pole is (t5 %att]$ or burn$4 ,su* a result does n necess>ily int]rupt ! transmission s]vice1 h[ev]1 z ! ne>-by poles c usually c>ry ! additional /ra9 ( ! l9e until a new pole c be set4 ,q a diff]5t result might be rea*$ if lightn+ or "s o!r cause broke an insulator on a /eel t[]1 & ?us all[$ "o ( ! electric cables to come into contact ) ! metal /ructure1 z ! conductor w\ld !n probably be burn$ 9 two4 ,to repair a heavy cable ?us sev]$ :]e ! spans 7 z mu* z #djj feet long w\ld c]ta9ly require "s little "t4 ,:]e a conductor 9 circuits op]at+ at #bj1jjj to #ce1jjj volts has 9 _m cases dropp$ onto a wood5 cross-arm1 x has (t5 rema9$ !re )\t damage until discov]$ by ! l9e inspector1 b no su* result c\ld be expect$ ) /eel t[]s & cross-arms 7xxi1 ,a4 ,i4 ,e4 ,e41 #gfj74 ,:]e /eel t[]s are employ$ x w\ld seem to be saf] to use wood5 cross-arms1 = ! reasons j /at$4 ,?is is1 9 fact1 ! practice on ! /eel t[]s be=e nam$ t support #be1jjj-volt circuits ov] ! ,*ambly ,canal1 & also on ! /eel t[]s t c>ry ! #fj1jjj-volt circuits f ,colgate p[]-h\se ov] ! mile-wide ,/raits ( ,c>qu9ez4 ,on ! #dj1jjj-volt transmission l9e betwe5 ,gromo & ,nembro1 ,italy1 :]e timb] is sc>ce & /eel is *eap1 bo? ! poles & cross-arms are ( wood4 ,x is ?\ght t ! comp>atively small numb] ( insulators us$ :]e a l9e is support$ at po9ts ab\t f\r hundr$ feet ap>t %\ld contribute to reliability 9 op]ation1 b insulators n[ give no m tr\ble ?an o!r p>ts ( ! l9e1 & ! leakage ( en]gy ov] _! surfaces is v small 9 am\nt1 z 0 %[n 9 ! ,telluride te/s4 ,:atev] b5efits are to be _h f long spans are z available ) wood5 z ) /eel supports1 & at less co/4 ,"o advantage ( /eel t[]s ov] wood5 poles or /ructures is t ! =m] w n burn & are probably n subject to de/ruction by lightn+4 ,:]e a long l9e passes ov] a t]ritory :]e !re is mu* bru%1 timb] or long grass1 ! fact t /eel t[]s w n burn may make _! *oice desirable4 ,9 tropical c\ntries :]e insects rapidly de/roy wood5 poles ! use ( /eel t[]s may be highly desirable ev5 at mu* great] co/1 & su* a case 0 p]haps pres5t$ on ! l9e to ,guanajuato1 ,mexico4 ,me*anical failures ( wood5 insulator p9s h be5 f> m common ?an ^? ( poles1 bo? z a direct result ( ! l9e /ra9s & because su* p9s are (t5 *>r$ & weak5$ by ! leakage ( en]gy f ! conductors4 ,= ^! reasons ! g5]al use ( iron or /eel p9s = ! insulators ( long l9es op]at+ at high voltages seems desirable4 ,su* p9s are n[ us$ to support ! insulators on a numb] ( l9es ) wood5 poles & cross-arms1 among :i* may be m5tion$ ! =ty-mile1 #cj1jjj-volt transmission betwe5 ,spi] ,falls & ,albany & ! =ty-five-mile #bh1jjj-volt l9e f ,be> ,riv] to ,ogd51 ,utah4 ,iron or /eel p9s add v little to ! co/ ( a l9e1 & mat]ially increase its reliability4 ,"o ( ! *eape/ & be/ =ms ( /eel p9s is t swag$ f a /eel pipe & hav+ a /raight %ank & tap]+ /em ) no %\ld]4 ,a p9 ( ?is sort = ! #djj-;foot spans ( #aij1jjj-;circul>-mil copp] cable on ! l9e f ,niag>a ,falls to ,toronto measures ?ree & "o-qu>t] in*es long 9 ! %ank1 elev5 & "o-half in*es 9 ! tap]1 & has diamet]s ( two & ?ree-eigh?s in*es at ! l>g] & "o & "o-eigh? in*es at ! small] end4 ,on spans "u #aej feet betwe5 wood5 poles p9s ( ?is type b ) a mu* small] diamet] c\ld be us$ to advantage4 ,on long transmission l9es :]e ! am\nt ( p[] involv$ is v l>ge ! additional reliability to be _h ) /eel t[]s is probably great en\gh to ju/ify _! use4 ,= ! great majority ( p[] transmissions1 h[ev]1 x seems probable t wood5 poles or /ructures w long cont9ue to be mu* ! *eap] & m practicable =m ( support4 ,! l9e ( /eel t[]s on a private "r ( way sev5ty-five miles long1 c>ry+ two circuits = ! transmission ( #bd1jjj horse-p[] at #fj1jjj volts f ,niag>a ,falls to ,toronto1 is "o ( ! mo/ prom95t examples ( ?is type ( con/ruction4 ,ev5tually !re w be two r[s ( /eel t[]s along ! entire l5g? ( ! l9e4 ,on ! /raight portions ( ! l9e ! /eel t[]s are regul>ly erect$ #djj feet ap>t1 b on curves ! di/ances are less betwe5 t[]s1 s t _! total numb] is ab\t #a1djj = ea* l9e4 ,/&>d curv+ along ! l9e requires t[]s plac$ #ej feet ap>t1 & a *ange 9 ! direction ( n m ?an t5 degrees at ea* t[]1 except at ! beg9n+ & end ( ! curve1 :]e ! *ange 9 direction is ?ree degrees4 ,:5 ! *ange 9 ! direction ( ! l9e is n m ?an six degrees1 ! correspond+ spans all[$ ) ea* *ange are z foll[s3 ,degrees ,feet ( *ange4 span4 #a_/b #cjj #a #bhf #a-a_/b #bgc #b #bei #b-a_/b #bdf #c #bcb #c-a_/b #bai #d #bje #d-a_/b #aib #e #agh #e-a_/b #afe #f #aea ,at "s po9ts along ! l9e conditions require a span betwe5 t[]s ( m ?an #djj feet1 ! regul> di/ance = /raight "w4 ,"o example ( ?is sort occurs at ,twelve-,mile ,creek1 :]e ! /ream has cut a wide1 deep gorge 9 ! ,erie plateau4 ,at ?is po9t ! l9es make a span ( #fbe feet betwe5 t[]s4 ,illu/ration3 ,,fig4 #id4--,transposition ,t[] 7,second ,t[]74 ,illu/ration3 ,,fig4 #ie4--;,elevations & ,plan ( ,t[]4 ,! regul> /eel t[] us$ 9 ?is transmission measures #df feet 9 v]tical height f its foot to ! tops ( ! l[] insulators1 & #ea feet #c in*es to ! tops ( ! high] insulators4 ,! l[] six feet ( ?is t[] are emb$d$ 9 ! gr\nd1 s t ! tops ( ! insulators measure ab\t #dj feet & #de feet #c in*es respectively above ! e>?4 ,at ! gr\nd ! t[] measures #ad feet at "r angles to ! transmission l9e & #ab feet p>allel ) x4 ,! wid? ( ea* t[] at ! top is #ab feet at "r angles to ! l9e1 & ! two sides hav+ ?is wid? come toge!r at po9ts ab\t #dj feet above ! gr\nd4 ,betwe5 ! two ,l b>s ?us br\ght ne>ly toge!r1 at ea* side ( a t[] a piece ( extra heavy #c-;in* /eel pipe is bolt$ s z to /& 9 a v]tical position4 ,ea* piece ( ?is pipe is ab\t #c-a_/b feet long & c>ries a /eel insulator p9 at its upp] end4 ,! two pieces ( pipe ?us fix$ on opposite sides ( ! top ( a t[] c>ry ! two highe/ insulators4 ,= ! o!r f\r insulators ( ea* t[]1 p9s are fix$ on a piece ( /&>d #d-;in* pipe t s]ves z a cross-arm1 & is bolt$ 9 a horizontal position betwe5 ! two ne>ly rectangul> sides ( ea* t[]1 at a po9t two feet bel[ ! bolts t hold ! v]tical #c-;in* pipes1 already nam$1 9 position4 ,save = ! two %ort v]tical & "o horizontal pipe1 & ! p9s !y support1 ea* t[] is made up ( ,l-%ap$ angle-b>s bolt$ toge!r4 ,ea* ( ! two ne>ly rectangul> sides ( a t[] consi/s ( two ,l b>s at its two edges1 ?ree ,l b>s = cross-braces at "r angles to ! edges1 & f\r diagonal braces also =m$ ( ,l b>s4 ,! l[] halves ( ! ,l b>s at ! edges ( ea* side ( a t[] h sections ( #c #c #a_/d1 & ! upp] halves h sections ( #c #c #c_/af4 ,?is la/-nam$ cross-brace & ! o!r two cross-braces h a common section ( #b #a-a_/b #a_/h4 ,= ! l[] set ( diagonal braces ! common section is #b-a_/b #b #a_/h1 & ! upp] set has a section ( #b #a-a_/b #a_/h 9 ea* memb]4 ,at ! level ( ! l[e/ cross-braces ! two rectangul> sides ( a t[] are ti$ toge!r by "o memb] ( #b #a-a_/b #a_/h ( ,l section & at "r angles to ! sides1 & by two diagonal braces ( #e_/h r\nd rod betwe5 ! corn]s ( ! t[]4 ,on ea* ( its two triangul> sides a t[] has f\r horizontal braces & ?ree sets ( diagonal braces4 ,! two upp] horizontal braces are ( #b #a-a_/b #a_/h ,l section1 & ! l[e/ is ! same1 b ! rema9+ horizontal brace has a section ( #b-a_/b #b #a_/h4 ,b>s ( #b #a-a_/b #a_/h ,l section are us$ = ! two upp] sets ( diagonal braces1 & b>s ( #b-a_/b #b #a_/h = ! l[] set4 ,9 addition to ! cross-braces nam$1 ea* triangul> side ( a t[] ne> ! top ( ! corn] b>s has two %ort cross-pieces ) ! common ,l section ( #c-a_/b #c-a_/b #e_/h1 "o j above & ! o!r j bel[ ! cross-arm ( #d-;in* pipe to hold x 9 place4 ,at ! bottom ( ea* ( ! f\r corn] b>s ( a t[] a foot is =m$ by rivet+ a piece ( #c #a_/d ,l section & #ae in*es long at "r angles to ! corn] b>4 ,on "o corn] b> ( ea* t[] !re are two r[s ( /eel /uds = /eps1 "o r[ be+ locat$ 9 ea* flange ( ! ,l section4 ,on ! same flange ^! /eps are two feet ap>t1 b tak+ bo? flanges !y are only "o foot ap>t4 ,e "p ( ea* /eel t[] is heavily galvaniz$4 ,illu/ration3 ,,figs4 #if1 #ig1 #ih4--,rais+ ,t[]s on ,niag>a ,transmission ,l9e4 ,illu/ration3 ,,fig4 #ii4--,"o ( ! ,t[]s 9 ,position4 ,! labor ( erect+ ^! /eel t[]s 0 r$uc$ to a l[ figure by ! me?od employ$1 z %[n 9 ! accompany+ illu/ration4 ,ea* t[] 0 br\ght to ! place :]e x 0 to /& ) its p>ts unassembl$4 ,= erect+ ! t[]s a f\r-:eel wagon ) a timb] body ab\t ?irty feet long 0 us$4 ,:5 x 0 desir$ to raise a t[]1 two ( ! :eels1 ) _! axle1 7 deta*$ f ! timb] body ( ! wagon1 & ?is body 0 !n /ood on end to s]ve z a sort ( d]rick4 ,?is d]rick 0 guy$ at its top on ! side away f ! t[]1 & a set ( blocks & tackle 0 !n connect$ to ! top ( ! d]rick & to ! t[] at a po9t ab\t "o-f\r? ( ! di/ance f its top4 ,a rope f ?is set ( blocks ran ?r\gh a s+le block fix$ to ! base ( ! d]rick & !n to a team ( horses4 ,on driv+ ^! horses away f ! d]rick ! /eel t[] 0 gradually rais$ on ! two legs ( "o ( its rectangul> sides until x came to a v]tical position4 ,! next op]ation 0 to br+ ! legs ( ! t[] into contact ) ! ext5sion pieces t 7 fix$ 9 ! e>? & !n bolt !m toge!r4 ,illu/ration3 ,,fig4 #ajj4--,/eel ,t[] = ,transmission ,l9e4 ,! tops ( ! ?ree p9s t c>ry ! insulators = ea* ?ree-phase circuit are at ! corn]s ( an equilat]al triangle 7,fig4 #ajj71 ea* ( ^: sides measures six feet4 ,! six /eel insulator p9s us$ on ea* t[] are exactly alike1 & ea* is swag$ f extra heavy pipe4 ,ea* f9i%$ p9 is #b-c_/h in*es 9 diamet] = a l5g? ( #c-a_/d in*es1 & !n tap]s uni=mly to a diamet] ( #a-a_/h in* at ! top ?r\gh a l5g? ( #aa-a_/b in*es4 ,?is gives ! p9 a total l5g? ( #ad-c_/d in*es4 ,9 ! l>g] "p !re are two #i_/af-;in* holes f side to side1 & )9 two in*es ( ! top !re are ?ree circul> grooves ea* #c_/af in* wide & #a_/af in* deep4 ,=g$ /eel sockets ( two types are employ$ to atta* ! /eel p9s ) ! pipes4 ,ea* socket is made 9 halves1 & ^! halves are secur$ to bo? ! pipe & ! p9 by ?r\gh bolts4 ,l all o!r p>ts ( ! t[]s1 ^! /eel p9s & sockets are heavily galvaniz$4 ,on ea* ( ! f\r corn] b>s ( a t[] ! l[] six feet ( its l5g? is secur$ to ! upp] "p by bolts or rivets4 ,?is l[] six feet ( ea* corn] b> is emb$d$ 9 ! e>?1 & ! con/ruction j nam$ makes x easy to replace ! b>s 9 ! e>? :5 corrosion makes x necess>y4 ,foot+s = ea* t[] are provid$ by digg+ f\r ne>ly squ>e holes ) _! sides at approximately #de degrees ) ! direction ( ! transmission l9e1 & ! %orte/ side ( ea* hole at lea/ two feet long4 ,c5tres ( ^! holes are #ad feet #c in*es ap>t 9 a direction at "r angles to ! l9e1 & #ac feet #i in*es ap>t p>allel ) ! l9e4 ,9 h>d-pan ea* "o ( ! holes 0 fill$ to )9 #b feet #f in*es ( ! top ) /ones1 aft] ! leg ( ! t[] 0 9 position1 & !n ! rema9d] ( ! hole 0 fill$ ) cem5t gr\t+ mix$ f\r to "o4 ,at ! bottom ( ea* hole 9 m>% l& a wood5 foot+ #c feet #f in*es #bd in*es 0 laid flat b5ea? ! leg ( ! t[]1 & !n ! hole 0 fill$ to )9 #b-a_/b feet ( ! surface ) ! excavat$ mat]ial4 ,next above ?is fill+ comes a galvaniz$ iron gutt]-pipe1 f\r in*es 9 diamet]1 & fill$ ) cem5t ab\t ! leg ( ! t[] = a l5g? ( two feet4 ,outside ( ?is pipe ! hole is made r\nd+ full ( cem5t gr\t+4 ,illu/ration3 ,,fig4 #aja4--,transmission ,l9e at ,well& ,canal4 ,at "s po9ts along ! transmission l9e exceptionally high t[]s are necess>y1 a notable in/ance be+ f\nd at ! cross+ ov] ! ,well& ,canal1 :]e ! l[e/ "p ( ea* span mu/ n be less ?an #aej feet above ! wat]4 ,= ?is cross+ two t[]s #ace feet high above gr\nd are us$1 z se5 9 ,fig4 #aja4 ,ea* ( ^! t[]s is design$ to c>ry all f\r ( ! ?ree-phase p[] circuits t are ev5tually to be erect$ betwe5 ,niag>a ,falls & ,toronto4 ,= ?is purpose !re 0 us$ a special design ( t[] ) a wid? ( ab\t #dh feet at "r angles to ! direction ( ! l9e bel[ ! top truss1 & a wid? ( ab\t #fh4e feet at t truss :]e ! two l[] conductors ( ea* circuit are atta*$4 ,) all spans long] ?an #djj feet1 a t[] ( heavi] con/ruction ?an ! /&>d type is us$1 & ?is t[] provides ?ree insulators = ! support ( ea* conductor4 ,a t[] ( ?is type t supports ! l[e/ conductors ab\t #dj feet above ! gr\nd level has its corn] b>s made up ( #d #d #c_/h & #d #d #e_/af ,l sections1 has ?ree cross-arms ( extra heavy #d-;in* pipe1 & a #f-;in* v]tical /&>d pipe to support ea* gr\p ( ?ree insulators = ! highe/ conductor ( ea* circuit4 ,ea* ( ! l[] conductors ( a circuit on ?is t[] is support$ by an insulator on ea* ( ! ?ree p>allel cross-arms4 ,on "s ( ^! t[]s1 = long spans1 ! two outside insulators = ! support ( ea* conductor are set a little l[] ?an ! insulator betwe5 !m4 ,illu/ration3 ,,fig4 #ajb4--;,heavy ,t[] at ,cr$it ,riv]4 ,illu/ration3 ,,fig4 #ajc4--;,angle ,t[] ,ne> ,bronte4 ,angle t[]s1 us$ :]e ! l9e makes a l>ge *ange 9 direction at a s+le po9t1 h ?ree legs on ea* rectangul> side1 a wid? ( #bj feet on ea* ( ^! sides = "s di/ance above ! gr\nd1 & a wid? ( #bg feet #b in*es at ! top4 ,9 ^! t[]s ! two legs on ! triangul> side t is 9 compression are ea* made up ( f\r #c #c #a_/d ,l sections jo9$ by #a-a_/b #a_/d lattices & rivets4 ,t[]s ( ?is sort are us$ ne> ! ,toronto t]m9al-/ation1 :]e ! l9e *anges #ce degrees at a s+le po9t1 & ne> ! cross+ ( ,twelve-,mile ,creek1 :]e ! angul> *ange ( ! l9e on a t[] is #de degrees4 ,close to ea* t]m9al-/ation & division-h\se ! transmission l9e is support$ by t]m9al t[]s4 ,^! t[]s diff] f ! o!rs 9 t ea* c>ries insulators = only ?ree conductors1 & ^! insulators are all at ! same level4 ,ea* t]m9al t[] has n9e insulators1 arrang$ 9 ?ree p>allel r[s ( ?ree ea* = ! conductors ( a s+le circuit1 & ea* conductor ?us has its /ra9 di/ribut$ betwe5 ?ree p9s4 ,all ?ree wires ( a circuit are held #dj feet above ! gr\nd by a t]m9al t[]1 & pass to _! entries 9 ! wall ( a /ation at ! same level4 ,z ^! t]m9al t[]s mu/ resi/ ! end /ra9 ( ! l9e1 !y are made extra heavy1 ! f\r legs ea* be+ made up ( #d #d #e_/af & #d #d #c_/h ,l sections4 ,= ! ?ree cross-arms on "o ( ^! t[]s ?ree pieces ( #d-;in* pipe1 ea* #ae feet #i in*es long1 are secur$ at its top ) _! p>allel c5tre l9es #cj in*es ap>t 9 ! same plane4 ,ea* ( ^! pipes c>ries ?ree insulator p9s ) _! c5tres #g feet #d-a_/b in*es ap>t4 ,on ! bottom ( ea* leg ( a t]m9al t[] !re is a foot1 =m$ by rivet+ on b5t plates1 t measure #ae & #ah in*es1 respectively1 on ! two long] sides4 ,ea* foot ( ?is t[] is set 9 a block ( concrete #e feet squ>e t ext5ds f #c4e feet to #g4e feet bel[ ! gr\nd level4 ,insulators = ! transmission l9e1 :i* are illu/rat$ 9 ,fig4 #ajd1 are ( br[n1 glaz$ porcela91 made 9 ?ree p>ts1 & cem5t$ toge!r4 ,! ?ree p>ts consi/ ( ?ree petticoats or ?imbles1 ea* ( :i* slips ov] or into "o ( ! o!rs1 s t !re are ?ree outside surfaces & ?ree int]ior or protect$ surfaces betwe5 ! top ( an insulator & its p94 ,f top to bottom ! height ( ea* insulator is #ad in*es1 & ?is is also ! diamet] ( ! highe/ & l>ge/ petticoat4 ,! next or middle petticoat has a maximum diamet] ( #aj in*es & ! l[e/ petticoat "o ( #h in*es4 ,cem5t holds ! l[e/ petticoat ( ! insulator on "o ( ! /eel p9s previ\sly describ$1 & 9 ?is position ! edge ( ! l[e/ petticoat is ab\t #b-a_/b in*es f ! /eel support4 ,at ! top ( ea* insulator ! transmission conductor is secur$1 & ! %orte/ di/ance f ?is conductor to any ( ! /eel p>ts ?r\gh ! air is ab\t #ag in*es4 ,f ! /ep-up trans=m] h\se at ,niag>a ,falls to ! t]m9al-/ation at ,toronto1 a di/ance ( sev5ty-five miles1 ea* ?ree-phase1 #fj1jjj-volt1 #be-;cycle circuit on ! /eel t[]s is made up ( ?ree h>d-drawn copp] cables ) a cross section ( #aij1jjj circul> mils ea*1 & is design$ to deliv] #ab1jjj electric horse-p[] ) a loss ( t5 p] c5t1 on a basis ( #ajj p] c5t p[] factor4 ,six equal /r&s ( copp] make up ea* cable1 & ?is wire has be5 specially drawn ) an ela/ic limit ( m ?an #ce1jjj p\nds & a t5sile /r5g? ( ov] #ee1jjj p\nds p] squ>e in*4 ,?is cable is made 9 uni=m l5g?s ( #c1jjj feet1 & ^! l5g?s are jo9$ by twi/+ _! ends toge!r 9 copp] sleeves1 & no sold] is us$4 ,no insulation is us$ on ^! cables4 ,illu/ration3 ,,fig4 #ajd4--;,insulators4 ,in/ead ( a tie-wire1 a novel clamp is employ$ to secure ! copp] cable on ea* insulator4 ,?is complete clamp is made up ( two sep>ate clamps t grasp ! cable at opposite sides ( ea* insulator & ( two half-circles ( h>d-drawn copp] wire ( #j4ahg in* diamet]4 ,ea* half-circle ( ?is wire jo9s "o-half ( ea* ( ! opposite clamps1 & fits ab\t ! neck ( ! insulator j bel[ its head4 ,two bronze ca/+s1 "o ( :i* has a bolt ext5sion t passes ?r\gh ! o!r1 & a nut1 make up ea* sep>ate clamp4 ,:5 ! comb9$ clamp is to be appli$1 ! sides are sep>at$ by remov+ ! nut t holds !m toge!r1 ! half-circles are br\ght ar\nd ! neck ( ! insulator1 & ea* ( ! side clamps is !n tight5$ on to ! cable by turn+ ! nut t draws its halves toge!r4 ,?is complete clamp c be appli$ z quickly z a tie-wire1 is v /rong1 & does n cut into ! cable4 ,ea* ( ! regul> /eel t[]s is design$ to )/& safely a side /ra9 ( #aj1jjj p\nds at ! insulators1 or an av]age ( #a1fff p\nds p] cable4 ,) ! #aij1jjj-mil cable coat$ to a dep? ( #a_/b in* ) ice & expos$ to a w9d bl[+ #ajj miles p] h\r1 ! e/imat$ /ra9s on ea* /eel p9 = diff]5t spans & angul> *anges 9 ! direction ( ! l9e are giv5 9 ! accompany+ table3 ,,p\nds ,,/ra9 ,,on ,,p9s1 #a_/b-;,,in* ,,sleet1 #ajj ,,miles ,,w9d4 ,degrees & ,m9utes4 ,span1---------------------------------- - feet4 #j #j4cj #a #a4cj #b #b4cj #c ---------------------------------------- #j #j #ce #fi #ajd #ach #agc #bjg #ajj #bef #bia #cbe #cfj #cid #dbi #dfc #bjj #eab #edg #eha #faf #fej #fhe #gai #cjj #gfh #hjc #hcg #hgb #ijf #ida #ige #djja1jbda1jeia1jica1abha1afba1aiga1bca #ejja1bhja1caea1cdia1chda1daha1deca1dhg #fjja1ecfa1egaa1fjea1fdja1fgda1gjia1gdc #gjja1giba1hbga1hfaa1hifa1icja1ifea1iii #hjjb1jdhb1jhcb1aagb1aebb1ahfb1bbab1bee #ijjb1cjdb1ccib1cgcb1djhb1ddbb1dggb1eaa #a1jjjb1efjb1eieb1fbib1ffdb1fihb1gccb1gf g ---------------------------------------- ,degrees & ,m9utes4 ,span1------------------------------ feet4 #c4cj #d #d4cj #e #e4cj #f ----------------------------------- #j #bdb #bgf #caa #cde #chj #dad #ajj #dih #ecb #efg #fja #fcf #fgj #bjj #ged #ghh #hbc #heg #hib #ibf #cjja1jaja1jdda1jgia1aaca1adha1ahb #djja1bffa1cjja1ccea1cfia1djda1dch #ejja1ebba1eefa1eiaa1fbea1ffja1fid #fjja1ggha1haba1hdga1hhaa1iafa1iej #gjjb1jcdb1jfhb1ajcb1acgb1agbb1bjf #hjjb1bijb1cbdb1ceib1cicb1dbhb1dfb #ijjb1edfb1ehjb1faeb1fdib1fhdb1gah #a1jjjb1hjbb1hcfb1hgab1ijeb1idjb1igd ----------------------------------- ,! copp] cables 7 s /rung z to h a m9imum di/ance f ! gr\nd ( #be feet at ! l[e/ po9ts ( ! spans4 ,9 ord] to d ?is ! /&>d /eel t[]s t hold ! l[] cables #dj feet above ! gr\nd level at ! insulators are spac$ at v>y+ di/ances ap>t1 accord+ to ! nature ( ! gr\nd betwe5 !m4 ,at ea* t[] ! upp] cable ( ea* circuit is #e feet #c in*es high] ?an ! two l[] cables1 & ?is di/ance betwe5 ! elevations ( ! upp] & ! l[] cables is ma9ta9$ :atev] ! am\nt ( sag at ! c5tre ( ea* span4 ,if !re is a depression betwe5 two /&>d t[]s on a /raight portion ( ! l9e1 ! sag 9 ! c5tre ( a span #djj feet long may be z mu* z #ah feet4 ,:]e a rise & fall 9 ! gr\nd betwe5 t[]s make x necess>y to limit ! sag to #ad feet 9 ord] to keep ! l[e/ cables #be feet above ! highe/ po9t ( e>?1 ! l5g? ( span is limit$ to #cej feet4 ,if ! rise & fall ( gr\nd level betwe5 t[]s all[ a sag ( only #aa feet ) ! l[e/ cable #be feet above ! e>?1 ! l5g? ( span ) #dj-;foot t[]s is r$uc$ to #cjj feet2 & if = a l reason ! sag is limit$ to #h feet1 ! span may only be #bej feet4 ,illu/ration3 ,,fig4 #aje4--,take-up ,arrangem5t on ,t]m9al ,t[]4 ,at ea* t]m9al t[]1 :]e ! cables are secur$ be=e !y pass into a t]m9al-/ation1 ! ?ree insulators = ea* cable are 9 a /raight l9e ) _! c5tres1 #cj in*es ap>t4 ,:5 a l9e cable rea*es ! fir/ insulator ( ! ?ree to :i* x is to be atta*$ on "o ( ^! t[]s1 x is pass$ ar\nd ! neck ( ?is insulator & !n secur$ on itself by means ( two clamps t are tight5$ ) bolts & nuts4 ,see ,fig4 #aje4 ,! cable ?us secur$ turns up & back ov] ! tops ( ! ?ree insulators & goes to ! t]m9al-/ation4 ,ar\nd ! neck ( ! insulator to :i* ! l9e cable has be5 secur$ 9 ! way j outl9$ a %ort deta*$ l5g? ( ! regul> copp] cable ) ! p>ts ( a turnbuckle at ea* end is pass$1 & ?is same piece ( cable also passes ar\nd ! neck ( ! next insulator 9 ! s]ies ( ?ree4 ,by jo9+ ! ends ( ! turnbuckle & tight5+ x1 a "p ( ! /ra9 ( ! l9e cable 9 "q is transf]r$ f ! fir/ to ! second insulator ( ! s]ies4 ,9 ! same way a "p ( ! /ra9 ( ?is same l9e cable is transf]r$ f ! second insulator ( ! s]ies to ! ?ird1 or "o ne>e/ to ! t]m9al-/ation4 ,,index4 ,air-bla/ cool$ trans=m]s1 #abi ,air-gap data1 #ahc ,air gaps1 numb] 9 s]ies to /& giv5 voltage1 #ahc ,albany-,hudson ,ry4 ,plant1 #aba ,alt]nat+ curr5ts1 #bbg ,alt]nator voltage1 #aah ,alt]nators1 #ajc data1 #aah = high voltage1 #abj inductor1 #aab types (1 #aaa ,alum9um z a conductor1 #bjj1 #bji cables 9 use1 #bac conductor jo9ts1 #bjf conductors1 #bg1 #bh corrosion (1 #baa prop]ties (1 #bab sold]$ jo9ts1 #bjf vs4 copp]1 #bji wire1 co/ (1 #bi ,amoskeag ,mfg4 ,co4 plant1 #ea1 #eb ,am/]dam 7,n4 ,y47 plant1 #aba ,an*or ice1 #ei ,&]son 7,s4 ,c47 plant1 #aba ,apple ,riv] 7,m9n47 plant1 #a1 #bf1 #bg1 #bh1 #ga1 #ig1 #ih1 #ii1 #ajb1 #aah1 #aai1 #abd1 #abf1 #abg1 #acd1 #agd1 #ahg1 #aij1 #aib1 #bjh1 #bde1 #bfd1 #bid ,arc light+1 #afg ,arc+1 #df ,automatic regulators1 #afb ,b>b$ wire1 #afi1 #age ,belt drive1 #hc1 #ajg ,bi5ne plant 7,switz]l&71 #db ,bir*em ,b5d1 #eg1 #fg1 #gi1 #ie1 #ig1 #ih1 #ajb ,bl[] capacity necess>y to cool trans=m]s1 #acj ,boo/]s1 #acc ,bo/on-,worce/] ,ry4 plants1 #aba ,braces = cross-arms1 #bei ,bronze conductors1 #bjj ,bru% dis*>ge1 #bha ,bu*anan 7,mi*47 plant1 #hh ,build+ mat]ials1 #ie ,bulls ,bridge plant1 #fc ,burr>d ,inlet 7,b4 ,c47 plant1 #aaa1 #aab ,bus-b>s1 #adb1 #adg dummy1 #ade ,cable insulation1 #aie %ea?s1 #aid ways1 #adj ,cables1 alum9um1 #bab alum9um1 9 use1 #bac *>g+ curr5t1 #aig co/ (1 #ahh1 #aif = alt]nat+ curr5t1 #aid high-voltage1 #aia pap] insulat$1 #aif protection aga9/ electrolysis1 #aie rubb]-cov]$1 #aie subm>9e1 #aib temp]ature (1 #aih voltage 91 #aij1 #aif ,canadian-,niag>a ,falls ,p[] ,co41 #aba ,canals1 #ea1 #ec long1 #fh ,caon ,city plant1 #bf1 #bg1 #bh1 #aag1 #aah1 #abg1 #bjh ,caon ,f]ry plant1 #a1 #c1 #bf1 #bg1 #bh1 #df1 #di1 #ec1 #fb1 #fh1 #fi1 #hc1 #hi1 #id1 #ie1 #ig1 #ajb1 #aje1 #aab1 #aac1 #aah1 #aai1 #abd1 #abe1 #abf1 #abg1 #acj1 #acb1 #acd1 #agd1 #bjh1 #bcc1 #bcd1 #bde1 #bdf1 #bdi1 #bed1 #beg1 #bei1 #bfh1 #bgb1 #bhj1 #bhb1 #bid1 #bie1 #cjb ,c$> ,lake plant1 #ij ,*ambly plant1 #if1 #aaj1 #adi1 #aef1 #agb1 #ahi1 #bdi1 #bee1 #bef1 #beg1 #bfg1 #bgb1 #bhg1 #bid1 #bie1 #caa1 #cab ,*>g+ curr5t = cable1 #aig ,*>r+ ( p9s1 #bgf1 #bgh ,*audire ,falls plant1 #aah ,*oke-coil us$ ) lightn+ arre/]s1 #ahj ,circuit break]s1 #ace1 #aej break]s1 "t limit1 #aeb ,circuits1 selection (1 #bcc ,coal1 price (1 9 ,salt ,lake ,city1 #h ,colgate plant1 #a1 #c1 #bf1 #bg1 #bh1 #gd1 #hb1 #hc1 #ij1 #id1 #ig1 #ih1 #ii1 #aja1 #ajb1 #ajh1 #aab1 #aac1 #aah1 #abg1 #acj1 #acb1 #acd1 #ahg1 #aij1 #bja1 #bjf1 #bjh1 #bac1 #bde1 #bdf1 #bej1 #bed1 #beg1 #bgb1 #bgg1 #bhj1 #bhb1 #bid1 #bie1 #cjd1 #cji ,columbus 7,ga47 plant1 #hc1 #aae ,comp\nd+1 #afj ,compressive /r5g? ( woods1 #cjb ,conductivity ( ! conductor metals1 #bja ,conductors1 #bjj alum9um1 #bg1 #bh1 #bjf alum9um1 prop]ties (1 #bab coeffici5ts ( expansion1 #bjj corrosion (1 #baa co/ (1 #bb1 #bi1 #bjc1 #bjd1 #bje co/ ( alum9um1 #bi co/ ( p] k4 w41 #bh co/ ( copp]1 #bi data1 #bjd data f repres5tative transmission plants1 #bjh expansion ( alum9um & copp]1 #baa melt+ po9ts1 #bjj m9imum size = transmission l9e1 #bjb prop]ties ( ideal1 #bjj relative conductivity1 #bja relative co/ (1 #bj relative prop]ties = equal l5g?s & resi/ances1 #bjd relative /r5g?s = giv5 area1 #bjc relative weight = giv5 conductivity1 #bjb relative weight (1 #bjb relative weights ( ?ree-phase1 two-phase1 & s+le-phase l9es1 #bbj resi/ance (1 #bbe sk9 effect1 #bjf1 #bcc weight p] k4 w41 #bg ,conduits1 #aie radiation loss 91 #aih temp]ature rise 91 #aih ,con/ant curr5t regulator1 #afg trans=m]1 #afg ,control equipm5t = d4 c4 & a4 c4 plants1 #ce ,copp] conductors1 #bjj co/ (1 #bb vs4 alum9um1 #bji wire1 co/ (1 #bi ,corrosion ( conductors1 #baa ,cross-arm braces1 #beh iron1 #bhd location (1 #beg mat]ial1 #beh ,cross-arms1 #di1 #bef ,cross+s1 #ahg ,dales plant 7,:ite ,riv]71 #bf1 #bg1 #bh1 #ga1 #acd1 #bjh ,dams1 #fb ,delta connection1 #aca ,depreciation1 #aa ,design ( p[]-plant1 #hc ,dike1 #fj ,direct connection1 #hd ,dis*>ge1 /atic1 #agj ,di/ribution sy/em1 #aeh ,draught tubes1 #gi ,dummy bus-b>s1 #ade ,ea/on 7,pa47 plant1 #aba ,edison ,co4 7,los ,angeles7 plant1 #aah ,effici5cy con/ant-curr5t transmission1 #baf curves1 motor-g5]ator set1 #aag ( con/ant-voltage transmission1 #bag ( trans=m]s1 #acc relative1 ( a4 c4 & d4 c4 transmission1 #ce ,electra plant1 #a1 #c1 #gd1 #hb1 #hc1 #ib1 #id1 #ig1 #ih1 #aja1 #ajb1 #ajh1 #aab1 #aac1 #aah1 #abg1 #agd1 #bjf1 #bjh1 #bab1 #bac1 #bcc1 #bce1 #bcf1 #bde1 #bdh1 #bec1 #bed1 #bef1 #bei1 #bgb1 #bge1 #bgg1 #bhj1 #bha1 #bhb1 #bid1 #bie ,electric p[]1 m>ket =1 #g ,electrical ,developm5t ,co41 ,niag>a plant1 #abj ,electricity vs4 gas1 #f ,electrolysis1 #aie ,en]gy curves ( hydro-electric /ations1 #ac electrical1 co/ ( at swit*bo>d1 #bc ,entrance end /ra91 #bfa1 #cbe insulat+ discs1 #bfb into build+s1 #agi ( l9es1 #agi1 #bfa1 #bfe ?r\gh ro(1 #bfi wall op5+s1 #bfb ,entries = transmission l9es1 #bfa ,expansion1 coeffici5t (1 = copp] & alum9um1 #baa coeffici5ts (1 = v>i\s conductor metals1 #bjj ,f>m+ton ,riv] 7,conn47 plant1 #bf1 #bg1 #bh1 #eh1 #aah1 #abe1 #acd1 #bjh1 #bab1 #bac1 #bde ,fe$]s1 #adc ,f]ranti cables1 #aib ,fire-pro(+1 #ie ,floor1 di/ance f ro( to1 #ie location (1 #gi space1 #ab1 #aja1 #ajb space p] k4 w4 ( g5]ators1 #ab ,floors1 #ie ,fog1 #df1 #bgg ,=e-bay1 #ei1 #fj ,f\ndations1 #ie ,frequ5cy1 #aac1 #abg effect on trans=m] co/1 #aaf ,fuel1 price (1 9 ,salt ,lake ,city1 #h ,fuses1 #ace1 #aej ,g>v9s ,falls plant1 #ef1 #fj1 #gi1 #hj1 #id1 #if1 #ig1 #ajb1 #aac1 #ade1 #bdj1 #bid ,gas vs4 electricity1 #f ,ge>s1 #hd1 #ajh ,g5]ators 7a4 c471 #ajc d4 c4 vs4 a4 c41 #ca ,g5]ators1 belt-driv51 #ajg capacity (1 #cb comp\nd+ (1 #afj co/ (1 #dj 7a4 c47 co/1 #cb 7a4 c47 data1 #aah direct-connect$ to horizontal turb9es1 #hi to impulse :eels1 #ij connection to v]tical %afts1 #hd 7d4 c47 field excitation (1 #da floor space1 #aja p] k4 w41 #ab ge>-driv51 #ajh 7a4 c47 high-voltage1 #abj 7d4 c47 9 s]ies1 #ca 7d4 c47 in/allation (1 #da insulation (1 #ci1 #de lightn+ protection1 #cd limit+ voltage (1 #dd 7a4 c47 limit+ voltage (1 #cb 7d4 c47 limit+ voltage (1 #ca ov]load capacity1 #ajc relation betwe5 voltage & capacity1 #abg revolv+ armatures1 #aab fields1 #aab s]ies-w\nd1 #da spe$ regulation1 #ch ,glass vs4 porcela9 insulators1 #bhh ,great ,falls plant1 #ed1 #fj1 #fa1 #fd1 #fg1 #gh1 #ib1 #ic1 #ajb1 #aad1 #aah ,greggs ,falls plant1 #ed1 #ef1 #fd1 #bdj ,gr\nd connections1 #agh = gu>d wires1 #aga1 #agb ,gr\nd$ gu>d wires1 #afh ,gu>d wires1 #afh in/allation (1 #age ,guy+ ( poles1 #bee ,hagneck 7,switz]l&7 plant1 #hf ,hooksett ,falls plant1 #ef1 #aca ,hydro-electric plants1 #a built at ! dam1 #fd-fg canals1 long1 #fh-gc long & %ort1 #eh %ort1 #ec-ef capacity & weight ( conductors p] k4 w4 = v>i\s plants1 #bg 7#hjj k4 w47 co/ (1 #aj 7#aejj k4 w47 co/ (1 #aa co/ ( labor1 #ab co/ ( op]ation1 #ab1 #gg design (1 #hc floor1 #gi space p] k4 w41 #aja int]e/ & depreciation1 #aa l9k$ toge!r1 #ef-eh load factors1 #ad1 #ae location (1 #fd model design1 #ab op]ation1 #ei vs4 /eam plant1 #e1 #ab ) pipe-l9es1 #gc-gg ) /eam auxili>y1 #hd ,ice1 #ei ,impulse :eel spe$1 #ajh :eels1 #hb1 #ij location (1 #ii ,indian ,or*>d plant1 #eg1 #hd ,inductance1 #bjf1 #bcj ,induction1 electro-magnetic1 electro/atic1 #afh on l9es1 #bjf regulator1 #afb ,inductor alt]nators1 #aab ,insulation1 z affect$ by ozone1 #aig co/ ( pap] vs4 rubb]1 #aif ( a4 c4 & d4 c4 l9es1 #cd ( app>atus1 #adb ( cables1 #aie ( electrical ma*9es1 #de ( g5]ators1 #ci protection aga9/ ozone1 #aih ,insulator arc-ov] te/1 #bia -p9s1 #bgj 7see ,p9s7 ,insulators1 #bgg1 #bhb1 #bhg1 #cbb & p9s1 data f v>i\s plants1 #bhj defective1 #bhh glass vs4 porcela91 #bhh 9 sn[1 #bic me?od ( fa/5+ to iron p9s1 #bga novel clamp1 #cbc on v>i\s transmission l9es1 #bid petticoats1 #bid te/+ (1 #bhh te/s1 #bij te/ voltage1 #bhi ) oil1 #bhg ,iron conductors1 #bjj ,kelley's ,falls plant1 #ef ,kelv9's law1 #bai ,labor1 co/ (1 #ab 9 hydro-electric /ations1 #ab ,leakage1 #bge1 #bhg l9e1 #bjg1 #bad ,lewi/on 7,me47 plant1 #aah1 #abj1 #abb1 #afg1 #bac ,light+1 inc&esc5t1 m9imum frequ5cy1 #aaf s]ies di/ribution1 #afg ,lightn+ arre/]1 effect ( s]ies resi/ance1 #ahe arre/]s1 #afh1 #agf gr\nd connection1 #agh multiple air-gap1 #agf1 #ahc non-arc+ metals 91 #ahd s]ies connection (1 #ahj %unt$ air-gaps1 #ahe ) *oke coil1 #ahj protection1 #cd ,l9e calculations1 #bba-bcb *>g+ curr5t1 #aig conductors1 #bjj conductors1 co/ (1 #bb weight (1 #ba con/ruction1 #bbb co/1 #caj cross-arms1 #di spac+ ( wires1 #df 7a4 c47 transmission1 #cd 7d4 c47 transmission1 #cc end /ra91 #cbe leakage1 #dg loss1 #ci losses due to gr\nd$ gu>d wires1 #agf ,l9es1 sag1 #cji transposition (1 #cad ,l9e voltages1 #de ,load factors1 #ad1 #ae light+1 #fa maximum1 #fj motor1 #afj railway1 #afd ,loss 9 conduits1 #aih relation to weight ( conductors1 #bae ,losses due to gr\nd$ gu>d wire1 #agf on transmission l9es1 #bae ,ludl[ ,mills plant1 #bf1 #bg1 #bh1 #eg1 #gi1 #ajj1 #aba1 #bjh1 #bac ,madrid 7,n4 ,m47 plant1 #bf1 #bg1 #bh1 #aah1 #bjh ,man*e/] 7,n4 ,h47 plants1 #abj ,m>ket = electric p[]1 #g ,mat]ials1 build+1 #ie = l9e-conductors1 #bjj ,me*anicsville plant1 #eh1 #fg1 #aji1 #aba1 #agd ,melt+ po9ts ( conductor metals1 #bjj ,montmor5cy ,falls plant1 #bf1 #bg1 #bh1 #bdj ,motor load1 #afj ,motor-g5]ator set effici5cy curve1 #aag ,motors1 s]ies-w\nd1 #da 7d4 c47 spe$ regulation1 #ch syn*ron\s1 #bda ,multiple air-gap arre/]1 #agf ,ne$le-po9t sp>k-gap = measur+ pressure1 #bij ,nev]s9k ,riv] plant1 #ge1 #agi ,niag>a ,falls ,p[] ,co41 #c1 #ei1 #ha1 #hf1 #hg1 #ic1 #id1 #ie1 #ig1 #aja1 #ajb1 #aje1 #ajf1 #ajg1 #ajh1 #aab1 #aac1 #aag1 #aah1 #aai1 #abg1 #acc1 #acg1 #adj1 #adc1 #ade1 #aea1 #aec1 #afa1 #afe1 #agj1 #aha1 #ahh1 #aid1 #aie1 #bjh1 #baa1 #bdj1 #bde1 #bdf1 #beg1 #bgb1 #bgc1 #bge1 #bhj1 #bhg1 #bhi1 #bid1 #bie1 #big ,nitric acid f air1 #bha ,non-arc+ metals1 #ahd ,nor? ,gorham 7,me47 plant1 #abj ,ogd5 7,utah7 plant1 #bf1 #bg1 #bh1 #aah1 #abj1 #acb1 #acd1 #bjh1 #bde ,ohm's law1 #bbc ,oil swit*es1 #acf ,ont>io ,p[] ,co41 #aba ,op]at+ exp5ses1 #ei ,op]ation1 co/ (1 #ab1 #gg ,op]ations1 reliability (1 #caa ,ouray 7,col47 plant1 #aba ,ov]head l9e connection to und]gr\nd1 #aig ,ov]load capacity ( g5]ators1 #ajc ,ozone1 #aig ,pa9t+ ( poles1 #bee ,pap] insulat$ cables1 #aif vs4 rubb] insulation1 #aif ,payette ,riv] 7,idaho7 plant1 #gc1 #aja ,p5/ocks1 #ei1 #ih ,phase1 #aac ,pike's ,peak plant1 #gg ,pilot wires1 #afa ,p9s1 #bei1 #bgj & insulators1 data f v>i\s plants1 #bhj burn+ (1 #bgj1 #bgf1 #bgh *>r+ (1 #bgf1 #bgh composite1 #bha compressive /r5g? ( woods1 #cjb design (1 #bih dim5sions (1 #cja =mula = diamet] (1 #bii iron1 #bge1 #bhe1 #bhf expansion (1 #bij me?od ( fa/5+ insulators1 #bga me?od ( fa/5+ to cross-arms1 #bga metal1 #bga1 #bge1 #bhb1 #bhe1 #bhf ( uni=m /r5g?1 #cjj1 #cjb proportions1 #cja relative co/ ( metal & wood51 #bhd %ank1 #bgd %\ld]1 #bge1 #bii1 #cje s(t5+ ( ?reads1 #bhj /eel1 #bge1 #cab /ra9 ) #a_/b-;in* sleet & #ajj-mile w9d = diff]5t spans1 #cbd /ra9s on1 #bgj1 #bih /r5g? (1 #cjc table ( /&>d1 #cja treatm5t (1 #bei1 #bge weake/ po9t1 #bih wood51 data f v>i\s plants1 #bgb dim5sions (1 #bgb dim5sions ( /&>d1 #bgc ,pipe-l9es1 #gc ,pittsfield 7,mass47 plant1 #aba ,pole l9e1 co/ (1 #ba lightn+ arre/]s1 #agi relative co/ (1 #bj l9es1 #bdf ,poles1 co/1 #caj dep? 9 gr\nd1 #bed diamet] (1 #bed dim5sions (1 #bed guy+ (1 #bee iron1 #bhd l5g? (1 #bec1 #cji life (1 #bee sett+ (1 #beb spac+ (1 #bdi /eel1 co/ (1 #cjg treatm5t (1 #bee woods =1 #beb ,porcela9 vs4 glass insulators1 #bhh ,portl& 7,me47 plant1 #abj1 #aff1 #bci ,portsm\?1 ,n4 ,h4 plant 7/eam71 #ajb1 #aah1 #aai1 #abj1 #aba1 #add1 #aid1 #bfd1 #bid ,p[] plant1 relative co/ ( a4 c4 & d4 c41 #cf transmitt$1 total co/ (1 #bd ,radiation loss 9 conduits1 #aih ,railway cross+1 #ahg1 #beb s]vice1 #afd ,r$ ,bridge plant1 #ec1 #fj1 #gi1 #ic1 #id1 #if1 #ig1 #ii1 #aja1 #ajb ,regulation1 #aee1 #bci z effect$ by syn*ron\s motors1 #afe at receiv+ end1 #afb h&1 #afa ,regulator1 automatic1 #afb con/ant-curr5t1 #afg induction1 #afb ,relay-swit*es1 #ade ,resi/ance1 #bbe 9 s]ies ) lightn+ arre/]1 #ahe ,revolv+ armature alt]nators1 #aab field alt]nator1 #aab ,riv] cross+s1 #ahg1 #aij1 #bdi ,ro(1 di/ance f floor1 #ie ,ro(s1 #ie ,rope-drive1 #hc ,rot>ies1 co/ (1 #aag suitable frequ5cy =1 #aae ,rubb]-cov]$ cables1 #aie maximum temp]ature1 #aih protection aga9/ ozone1 #aih ,sag 9 l9es1 #cji ,/4 ,hyac9! 7,que47 plant1 #aah ,/4 ,joseph plant1 #ff ,/4 ,maurice plant 7,switz]l&71 #ca ,salem 7,n4 ,c47 plant1 #aba1 #abb ,san ,gabriel ,caon plant1 #bf1 #bg1 #bh1 #bjh ,santa ,ana plant1 #a1 #bf1 #bg1 #bh1 #gd1 #gf1 #hb1 #hc1 #ib1 #id1 #ie1 #if1 #ig1 #ih1 #ii1 #aja1 #ajb1 #bjh1 #bde1 #bfc1 #bhj1 #bha1 #bid1 #bie1 #bif ,sault ,/e4 ,m>ie plant1 #gb1 #hc1 #he1 #hi1 #ig1 #ajb1 #ajd1 #aje1 #aab1 #aac1 #aag1 #aah1 #abj1 #abg ,scott sy/em1 #acb ,s]ies di/ribution1 #afg ma*9es1 #da ,sewall's ,falls plant1 #bf1 #bg1 #bh1 #aee ,%aw9igan ,falls plant1 #a1 #gj1 #ga1 #ajg1 #aaf1 #aag1 #afc1 #afd1 #aff1 #bji1 #bab1 #bac1 #bce1 #bcf1 #bdb1 #bde1 #bfg1 #bgb1 #bgc1 #bhj1 #bhb1 #bid1 #bie1 #bif ,%ea?s = cables1 #aid ,%unt$ air-gaps1 #ahe ,sk9 effect1 #bjf1 #bcb ,snoqualmie ,falls plant1 #c1 #d map ( transmission l9es1 #d ,sn[1 #bic ,sold]$ jo9ts1 #bjf ,spac+ ( poles1 #bdi ( wire1 #bcd ,spans1 long1 #aij1 #bej /ra9s = diff]5t l5g?s1 #cbd ,sp>k+ di/ances1 #ahb voltages1 #ahb ,spe$1 p]iph]al1 ( impulse :eels1 #ajh p]iph]al ( turb9es1 #he1 #ajc regulation1 #ch1 #db d4 c4 motors1 #ch ,spi] ,falls plant1 #a1 #b1 #c1 #ed1 #eh1 #fa1 #fb1 #fh1 #ia1 #id1 #ih1 #abd1 #abf1 #abg1 #acj1 #ada1 #adb1 #adf1 #afa1 #agd1 #bcf1 #bcg1 #bdc1 #bdd1 #bde1 #bej1 #bec1 #bff1 #bhj1 #bhe1 #bhg1 #bhi1 #bia1 #bid1 #bie1 #bif1 #cab ,/> connection1 #aca ,/atic dis*>ges1 #agj ,/eam & wat]-p[] /ation comb9$1 #hd electric plant1 co/ ( labor1 #ab co/ ( op]ation1 #ab floor area p] k4 w41 #ajb vs4 wat]-p[]1 #e ,/eel t[]s1 #cjf ,/orage capacity1 #ae ,/ra9s on insulation z affect$ by resi/ance 9 s]ies ) arre/]1 #ahe ,/ray curr5ts1 protection aga9/1 #aie ,subm>9e cables1 #ahg1 #aib1 #aid ,sub-/ation1 arrangem5t ( app>atus1 #abh ,sub-/ations1 #aeg1 #bcg ,surges1 #acf ,swit*bo>d1 #aef wir+1 #adf1 #adh1 #adi ,swit*es1 #ace1 #bdd arc+ (1 #ace electrically op]at$1 #adj long break1 #ace oil1 #acf op5-air1 #acf pneumatically op]at$1 #adj p[] op]at$1 #ach relay1 #ade ,swit*-h\ses1 #ada1 #adb1 #bch1 #bdd ,swit*+1 #adf high-t5sion1 #adg ,syn*ron\s conv]t]s1 #aae co/1 #aag motors1 #afe1 #bda ,tail-race1 #if ,telephone1 #afa ,telluride plant1 #dg1 #afj1 #afi1 #aha ,temp]ature ( cables1 #aih rise 9 conduits1 #aih ,t5sile /r5g? ( conductor metals1 #bja ,"t-limit circuit-break]1 #aeb ,"t relays1 #aeb1 #aec ,t[]s1 #bej1 #cjf angle1 #cbj co/1 #caj dim5sions1 #cad erection (1 #caf-cai heavy1 #cbj reliability ( op]ation1 #caa spans1 #cac /eel1 co/1 #cjg1 #cjh /eel p9s1 #cab /ra9 on1 #cbd ,trans=m]s1 #abb air-bla/ vs4 wat]-cool$1 #abi artificially cool$1 #abi at sub-/ations1 #abe bl[] capacity necess>y to cool1 #acj con/ant-curr5t1 #afg cool+1 quantity ( wat] necess>y1 #abi co/1 #ba1 #aaf1 #abd1 #acd co/ ( op]ation1 #abi co/ (1 relative1 #bj delta & /> connections1 #aca effici5cy1 #acc frequ5cy1 effect (1 #aaf insulation1 #de 9 transmission sy/ems1 #acd limit+ voltage =1 #cb location (1 #ig polyphase1 #abd regulation1 #abe res]ve1 #adi second>y1 9 s]ies1 #aca s+le-phase1 #abd two- to ?ree-phase1 #acb us$ to comp5sate drop1 #acc us$ to regulate voltage1 #afb voltages1 #de :5 to use1 #abb ,transmission1 con/ant-curr5t1 #ch1 #baf con/ant-voltage1 #dj1 #bag cont9u\s-curr5t1 #ca1 #cb control equipm5t1 #ce co/ (1 #ai1 #dj1 #bbb 7d4 c47 co/ (1 #dj effici5cy1 #ce1 #da fir/ long l9e1 #cg frequ5cy1 #aac g5]ator end1 #ajc lightn+ protection1 #cd limit+ voltage1 #dd l9es1 arc+1 #df calculation (1 #bba-bcb *>g+ curr5t1 #aig con/ruction1 #bbb co/1 #caj cross-arms1 #di1 #bef cross+s1 #ahg1 #aij data f v>i\s plants1 #bde effect ( l5g? on co/1 #bj effect ( l5g? on co/ ( p[]1 #bd effici5cy1 #bb1 #bd end /ra9 at entries1 #cbe entrance to build+s1 #agi1 #bfa inductance1 #bjf induction1 #afh insulation1 #cd insulators 7see ,insulators71 #bhg insulator-p9s 7see ,p9s71 #bgj int]e/1 ma9t5ance & depreciation1 #bb leakage1 #dg1 #bjg1 #bad l5g? (1 capacity (1 population suppli$1 #h lightn+ arre/]s 7see ,lightn+ ,arre/]s71 #agi lightn+ protection1 #aah long spans1 #aij loss1 #bb1 #ci losses1 #bae maximum inve/m5t 91 #bbj me?od ( fa/5+ conductors to insulators1 #cbc op]ation1 #caa pole spac+1 #bdi regulation ) syn*ron\s motors1 #bda relative weights ( ?ree-phase1 two-phase1 & s+le-phase1 #bbh "r-(-way1 #bdf sag 91 #cji spac+ ( wire1 #bcd /eel t[]s 7see ,t[]s71 #cjf swit*-h\ses1 #bch swit*es1 fuses1 & circuit-break]s1 #ace take up1 arrangem5t =1 #cbe total co/ (1 #bb total co/ ( op]ation1 #bc transposition ( wires1 #bjf1 #cad voltage1 #ba1 #bae 9 cables1 #aij regulation1 #acj w9d pressure1 #baj long l9e1 #bba m9imum-siz$ wire1 #bjb physical limits (1 #dd a4 c4 pole l9e con/ruction1 #cd d4 c4 pole l9e con/ruction1 #cc pole l9es1 #bdf problems1 #ai regulation1 #aee1 #bci selection ( circuits1 #bcc s+le vs4 p>allel circuits1 #bda spac+ ( conductors1 #df subm>9e1 #ahg ?ree-phase1 #aac ?ree-phase & two-phase1 #bbh two-phase1 #aac und]gr\nd1 #ahg )\t /ep-up trans=m]s1 #abj ,transposition ( wires1 #bjf ,turb9es1 high-spe$1 #ajg horizontal1 #gi1 #hc1 #hi1 #ig impulse1 #hb1 #ij1 #ii spe$ (1 #ajh l[-head good spe$1 #aje p]iph]al1 spe$ (1 #he1 #ajc pressure1 #gi sev]al on same %aft1 #he1 #aje v]tical1 #gi1 #hd1 #he1 #hf1 #ig ,und]gr\nd cable connect$ to ov]head l9e1 #aig cables1 #ahg ,victor 7,colo47 plant1 #bf1 #bg1 #bh1 #bjh ,virg9ia ,city plant1 #aah ,voltage drop comp5sation1 #acc fluctuations1 #bah high1 alt]nators1 #abj measurem5ts1 #bij 9 cables1 #aij1 #aif limit+1 #dd = a4 c4 ma*9es1 #cb = d4 c4 ma*9es1 #ca ( transmission l9es1 #ba1 #bae regulation1 #acj1 #aee sp>k+1 #ahb te/ = insulators1 #bhi ,volts p] mile1 #bf ,wages paid att5dants1 #ab ,walls1 #ie ,wa%+ton ,baltimore ,ry41 #aba ,wa%\ts1 #ha ,wat]-cool$ trans=m]s1 #abi ,wat]-p[]1 developm5t (1 #ea high head1 #gd-gg l[ head1 #ea-gd p] c5t4 ( en]gy available1 #af pure hydraulic developm5t1 #ea /ations 7see ,hydro-electric ,/ations7 /orage capacity1 #ae1 #fa utilization (1 #aj vs4 /eam1 #e ,wat]1 /orage (1 #ae1 #fa ,weight ( ! conductor metals1 #bjb ,well& ,canal plant1 #a1 #bf1 #bg1 #bh1 #bjh1 #bde1 #bdh ,we/brook 7,me47 plant1 #abj ,:ite ,riv] to ,dales plant1 #bf1 #bg1 #bh1 #ga1 #acd ,w9d1 #cbd pressure on l9es1 #baj ,w9ooski ,riv] plant1 #fd ,wire room1 #aci ,wood1 compressive /r5g? (1 #cjb ,woods = poles1 #beb ,yadk9 ,riv] 7,n4 ,c47 plant1 #bf1 #bg1 #bh1 #aah1 #bjh ,transcrib]'s ,notes ,?is transcription uses ! text ( ! orig9al "w4 ,inconsi/5cies 7e4g41 p] c5t4 & p] c5t2 ,*ambly & ,*amblay2 ,g>v9's & ,g>v9s ,falls2 #a-j & #a_/j ,b4 ,s4 gauge2 hyph5ation2 capitalisation2 use ( italics1 etc47 h be5 reta9$1 except z m5tion$ bel[4 ,"s ( ! calculations 9 ! book give diff]5t results to ! ones provid$2 ^! h n be5 correct$4 ,9 ?is book1 8cm40 /&s = circul> mils1 n = c5timet]s4 ,page #gf1 ,fig4 #af3 ! text 9 ! c5tre ( ! illu/ration probably reads #abjj feet ,pipe ,l9e4 ,page #aaa3 betwe5 figures #dd & #df ! orig9al book has figure #ea;a2 ! numb]+ has n be5 *ang$4 ,*anges made3 ,obvi\s m9or typographical & punctuation errors h be5 correct$ sil5tly4 ,fractions h be5 /&>dis$ to x_/y2 all occurr5ces ( vs4 h be5 italicis$4 ,9-l9e multi-l9e =mulas h be5 *ang$ to s+le-l9e =mulas4 ,table ( ,cont5ts3 ! ,index has be5 add$4 page #ae3 table head] *ang$ to small caps z o!rs page #ca3 ,electrical transmission *ang$ to ,electrical transmissions page #ef3 ,canon *ang$ to ,caon page #gg3 ,tlaluepantla *ang$ to ,tlalnepantla page #cab3 ,teluride *ang$ to ,telluride page #ccb3 ,canon *ang$ to ,caon4