,transcrib]'s ,note3 ,bold text is surr\nd$ by equal signs & italic text is surr\nd$ by und]scores4 ,,w> ,,dep>tm5t ,,(fice ,,( ,,! ,,*ief ,,signal ,,(fic] ,,manual ,no4 #f ,,visual ,,signal+ ,,signal ,,corps ,,unit$ ,,/ates ,,army #aiaj ,illu/ration ,,wa%+ton ,,gov]nm5t ,,pr9t+ ,,(fice #aiaj ,,w> ,,dep>tm5t1 ,docum5t ,no4 #cff4 ,,(fice ,,( ,,! ,,*ief ,,signal ,,(fic]4 ,,w> ,,dep>tm5t1 ,,(fice ,,( ,,! ,,*ief ,,( ,,/aff1 ,wa%+ton1 ,april #bj1 #aiaj4 ,! foll[+ ,manual ( ,visual ,signal+1 prep>$ 9 ! ,(fice ( ! ,*ief ,signal ,(fic]1 is approv$ & h]e) publi%$ = ! in=mation & guidance ( ! ,regul> ,army & ! ,organiz$ ,militia ( ! ,unit$ ,/ates1 & sup]s$es all o!r pamphlets or simil> in/ructions h]et(ore issu$ ^u ! subject4 ,(fic]s & m5 ( ! ,signal ,corps w ?or\ghly famili>ize !mselves ) ! in/ructions & sugge/ions conta9$ h]e94 ,by ord] ( ! ,secret>y ( ,w>4 ,,task] ,h4 ,,bliss1 ,brig4 ,g5]al1 ,g5]al ,/aff1 ,act+ ,*ief ( ,/aff4 ,,table ,,( ,,cont5ts4 ,page4 ,,*apt] ,i4--,,introduction #i ,,*apt] ,,ii4--,visual signal+ equipm5t4 ,! w& #aa ,! flag kit3 ,! #b-;foot flag kit #ab ,! #d-;foot flag kit #ab ,c>e ( flag mat]ial #ac ,p[]s & limitations ( flag signal+ #ac ,! heliograph3 ,hi/orical #ad ,description #ad ,assembl+ #ag ,adju/m5t #bj ,op]ation #ba ,c>e ( app>atus #bb ,p[]s & limitations ( ! heliograph #bb ,! signal lant]n3 ,acetyl5e #bc ,calcium c>bide #bc ,me?od ( gas g5]ation #bd ,description #be ,op]ation & c>e #cj ,p[]s & limitations ( ! signal lant]n #ce ,rockets & %ells3 ,description #ce ,op]ation #ch ,employm5t #dj ,! semaphore3 ,description #dj ,! se>*light3 ,me?ods ( employm5t #da ,! ,co/on signals #da ,v's night signals #db ,! ,ardois sy/em ( signal+ #db ,s\nd signals #dd ,improvis$ signal me?ods #dd ,,*apt] ,,iii4--,alphabets or sy/ems ( signals4 ,signal alphabets3 ,am]ican ,morse #de ,cont95tal ,morse #de ,army & navy #de ,abbreviations #df ,code calls #dg ,execution ( signal alphabets #dg ,! army & navy alphabet #dg ,! ,morse alphabets #di ,int]national code ( signals3 ,description #ea ,two-arm semaphore #ea ,! ,ardois sy/em #eb ,co/on signals #ed ,v's night signals #ed ,rocket signal+ #ee ,two-arm semaphore alphabet1 ,u4 ,s4 ,navy #eg ,summ>y ( signals1 army & navy alphabet #fj ,,*apt] ,,iv4--,! field message4 ,def9ition #fd ,! blank =m #fd ,writ+ ! message #ff ,in/ructions to op]ators3 ,use ( message blank #ff ,duties ( s5d+ op]ators #ff ,ord] ( transmission #ff ,duties ( receiv+ op]ators #fg ,communications confid5tial #fg ,*eck+ ! message #fg ,,*apt] ,v4--,! signal /ation4 ,location ( /ations3 ,g5]al consid]ations #fh ,backgr\nds #gj ,azimu? ( /ations #ga ,altitude #ga ,det]m9ation ( backgr\nd color #gb ,*oice ( app>atus #gc ,miscellane\s consid]ations #gc ,int]visibility table #gd ,f9d+ a /ation #ge ,op]ation ( /ations3 ,p]sonnel #gf ,calls & p]sonal signals #gh ,op5+ communication #gi ,comm5c+ ! message #hj ,s5d+ & receiv+ #hj ,break+ #hj ,discont9uance ( transmission #ha ,ackn[l$gm5t ( receipt #ha ,/ation records #ha ,=mation ( signals #hb ,repeat+ ! message #hc ,signal practice #hc ,,*apt] ,,vi4--,codes & ciph]s4 ,codes 9 use #hd ,employm5t ( codes #hd ,ciph] code #he ,! ,w> ,dep>tm5t ,code #hf ,ciph] code 9 field "w #hg ,field ciph]s3 ,description & use #hg ,=ms ( field ciph] #hh ,inv]sions #hh ,concealm5t ( t]m9ations #hh ,ciph] app>atus3 ,! ciph] disk #hi ,! ma!matical ciph] #ic ,! r\te ciph] #id ,ciph] detection3 ,employm5t ( ciph] disk #if ,,*apt] ,,vii4--,field glasses & telescopes4 ,reflection #ih ,refraction #ih ,l5ses #ih ,focus #ii ,optical c5t] #ii ,image #ii ,conjugate foci #ii ,law ( foci #ajj ,=mation ( image #aja ,sph]ical ab]ration #ajb ,*romatic ab]ration #ajb ,telescopes #ajd ,galilean field glasses & telescopes #ajf ,porro prism field glasses & telescopes #ajf ,field glasses #ajh ,prop]ties ( telescopes & field glasses #aji ,p[] #aji ,light #aaa ,field #aad ,def9ition #aae ,field glasses & telescopes issu$ by ! ,signal ,corps #aai ,type ,a #aba ,type ,b #abd ,type ,c #abe ,type ,d #abe ,field-glass specifications #abf ,,*apt] ,i4 ,,introduction4 ,:ile1 9 consequ5ce ( ! developm5t ( electrical inv5tion & improvem5t1 visual signal+ w be less frequ5tly resort$ to 9 future ?an h]et(ore 9 ! s]vice ( field l9es ( in=mation1 x %\ld be appreciat$ t ! necessity = an adequate supply ( app>atus ( ?is k9d1 & ! ne$ = skill$ manipulators to op]ate x1 has 9 no wise dim9i%$4 ,! great cel]ity ) :i* electric signals c be ex*ang$ & _! usual entire indep5d5ce ( local conditions has plac$ sy/ems ( ?is class =emo/ among ! signal+ me?ods ( ! _w4 ,!re is sc>cely any comm]cial indu/ry ^: successful exi/5ce does n vitally dep5d ^u "s "o1 p]haps sev]al sy/ems ( signal+1 & improvem5ts ( old & inv5tions ( new signal devices are cont9ually necess>y to meet ! requisite ne$s dem&$ by ! progress ( art & sci5ce4 ,railways are probably ! greate/ ( all comm]cial us]s ( signals4 ,) !m ! great mass ( intellig5ce is transmitt$ by ! electric telegraph & telephone1 b ! flag1 ! semaphore1 ! signal light1 & _m o!r contrivances furni% indisp5sable visual adjuncts4 ,visual signal+ is & always w be a mo/ valuable means ( transmitt+ in=mation 9 peace & w>1 & x is n to be imag9$ t x w ev] be supplant$ 9 its p>ticul> function by ! introduction ( o!r me?ods4 ,occasions w frequ5tly occur 9 ! field :5 no o!r means w be practicable1 & !n1 if n be=e1 w ! value ( ! sy/em be fully emphasiz$4 ,/rictly speak+1 a visual signal is any visible sign by :i* intellig5ce is communicat$1 b 9 a milit>y s5se ! t]m visual signal+ has a broad] mean+ & includes o!r me?ods ( transmitt+ in=mation ?an ^? :i* appeal to ! s5se ( sight4 ,9 mo/ sy/ems ( signals suitable = milit>y use1 ea* signal is compos$ ( "o or m sep>ate units1 kn[n z elem5ts4 ,hav+ prescrib$ a c]ta9 numb] ( elem5ts1 ! v>i\s signals are =m$ by hav+ ^! elem5ts appe> s+ly or toge!r 9 diff]5t arrangem5ts or comb9ations4 ,! cont95tal sy/em is "o ( two elem5ts1 namely ! dot & ! da%1 :ile ! ,morse sy/em employs ?ree elem5ts1 ! dot1 ! da%1 & ! space4 ,hav+ agre$ ^u a c]ta9 numb] ( comb9ations ( elem5ts1 a sy/em ( signals is =m$ by giv+ a mean+ to ea* comb9ation4 ,^! mean+s usually include ! lett]s ( ! alphabet & num]als1 comb9ations ( :i* be+ us$ to =mulate necess>y in=mation4 ,comb9ations ( elem5ts ( any sy/em c also1 h[ev]1 be us$ to indicate any desir$ mean+4 ,) ref]5ce to p]iod ( visibility1 signals are ( two k9ds1 transi5t & p]man5t4 ,a transi5t signal is "o :i* disappe>s z soon z complet$2 a p]man5t signal is "o t rema9s 9 view = "s "t4 ,heliograph signals are transi5t signals1 :ile signals made by code flags are p]man5t signals4 ,signals are divid$ into classes 9 accordance ) ! numb] ( elem5ts employ$ 9 _! =mation4 ,?us1 signals us+ two elem5ts are signals ( ! second class1 signals us+ ?ree elem5ts signals ( ! ?ird class1 etc4 ,! /&>d app>atus us$ 9 visual signal+ is fully describ$ 9 a succe$+ *apt]4 ,"s ( ! in/rum5ts employ$ are us$ :olly = day1 & "s :olly = night1 signal+4 ,"s devices1 ei!r ) or )\t slight v>iations1 are equally well adapt$ to day or night "w4 ,visual signal+ pres5ts a great field = +5i\s & res\rceful "w1 & em]g5cy w (t5 dem& ! advantage\s employm5t ( o!r me?ods ?an ^? describ$ h]e94 ,,*apt] ,,ii4 ,,visual ,,signal+ ,,equipm5t4 ,,! ,,w&4 ,! w& is a /ick ( light wood ab\t #ah in*es long & "o-half in* 9 diamet]4 ,x is held loosely betwe5 ! ?umb & =ef+] & wav$ rapidly to ! "r or left to indicate ! elem5ts ( ! alphabet4 ,x is us$ = practice purposes & ! signals made by x are only int5d$ to be read at v %ort di/ances4 ,,! ,,flag ,,kit4 ,two k9ds ( flag kits1 ! #b-;foot kit & ! #d-;foot kit1 are issu$ by ! ,signal ,corps4 ,! #b-;foot kit4--,?is kit consi/s ( "o :ite & "o r$ signal flag1 two ?ree-jo9t$ /affs1 & a suitable c>ry+ case to conta9 ! outfit4 ,! :ite flag is made ( :ite musl9 #b feet squ>e1 ) an #h-;in* turkey-r$ musl9 c5t]4 ,! r$ flag is ( simil> size & mat]ial1 ! only diff]5ce be+ an alt]nation ( colors 9 ! body & c5t]4 ,! means ( atta*m5t to ! /aff consi/s ( a loop at ! c5t]1 & two ends ( :ite tape at ea* edge1 ( ! back ( ! flag body4 ,! /aff is made ( hickory 9 ?ree jo9ts1 ea* #bc in*es long1 & is assembl$ by telescop+ into brass f]rules4 ,brass eyes are provid$ on ! fir/ & second jo9ts to receive ! tape ends at ! edge ( ! flag4 ,! c>ry+ case1 ( conv5i5t size & %ape to conta9 ! two flags & /affs complete1 is made ( #h-ounce /&>d khaki b\nd ) lea!r & fitt$ ) a %\ld] /rap4 ,! #b-;foot kit is ess5tially a practice kit1 al?\gh "u favorable conditions ( wea!r & t]ra9 x may be us$ to advantage z a %ort di/ance s]vice signal+ outfit4 ,two ( ^! kits are issu$ to ea* troop1 batt]y1 & company = ! purpose ( dissem9at+ g5]al in/ruction 9 milit>y signal+ ?r\gh\t ! army4 ,! #d-;foot kit4--,?is kit is ( ess5tially ! same description z ! #b-;foot kit except z reg>ds size4 ,! flags are #c feet #i in*es squ>e ) #ab-;in* c5t]s & ! /affs are consid]ably heavi]1 ! jo9ts be+ ea* #cf in*es long4 ,! #d-;foot kit is ! /&>d field flag kit & ! range at :i* signals c be ex*ang$ ) x dep5ds on a v>iety ( factors1 su* z ! condition ( ! wea!r1 ! location ( /ations1 ! pr(ici5cy ( signalm51 etc4 ,! spe$ = cont9u\s signal+ is seldom great] ?an five to six words p] m9ute4 ,c>e ( flag mat]ial4--,signal flags %\ld be exam9$ at ! close ( drill or practice & repairs made to any r5ts or loose ties discov]$4 ,flags1 :5 soil$1 %\ld be ?or\ghly wa%$ & dri$ 9 ! sun4 ,signals made by clean flags are mu* m easily read ?an ^? made by dirty ones4 ,/affs %\ld be h&l$ ) c>e1 especially :5 jo9t+ or unjo9t+4 ,c>e %\ld be tak5 n to bruise ! ends ( ! brass f]rules4 ,if a f]rule becomes loose on a /aff x %\ld be tight5$ )\t delay4 ,p[]s & limitations ( flag signal+4--,! advantages :i* may be claim$ = ?is me?od ( signal+ are portability ( app>atus1 adaptability to v>i$ wea!r conditions1 & great rapidity ( /ation e/abli%m5t4 ,! disadvantages are ! lack ( cel]ity ( ! signals1 _! imp5etrability to du/ or smoke1 & ! comp>atively %ort ranges at :i* !y c be read4 ,,! ,,heliograph4 ,! heliograph is an in/rum5t design$ = ! purpose ( transmitt+ signals by means ( ! sun's rays4 ,hi/orical4--,exp]im5ts ) ! heliograph ) a view to its adoption z a "p ( ! visual signal+ equipm5t ( ! ,unit$ ,/ates ,army 7 comm5c$ z e>ly z #ahgh4 ,! report$ successful use ( ! in/rum5t by ! ,briti% 9 ,india ab\t ?is "t l$ to ! importation ( two heliographs ( ! ,mance patt]n4 ,a s]ies ( exp]im5ts ) ^! ma*9es conduct$ = ! purpose ( elim9at+ c]ta9 objectionable features f9ally result$ 9 ! evolution ( ! pres5t type ( s]vice heliograph4 ,! e>ly ,engli% heliograph 0 n provid$ ) a %utt]1 ! fla% be+ direct$ on ! di/ant /ation by means ( a movable mirror controll$ by a key4 ,! great objection to ?is type ( in/rum5t 0 ! impossibility ( ma9ta9+ accurate adju/m5t dur+ ! transmission ( signals due to ! fact t ! manipulation ( ! mirror t5d$ to ?r[ ! fla% con/antly out ( alignm5t4 ,to ov]come ?is1 ! ,am]ican heliograph has be5 provid$ ) a scre5 design$ to op]ate z a %utt] & control ! fla% reflect$ f an immobile mirror4 ,description4--,! s]vice heliograph equipm5t ( ! ,signal ,corps consi/s (3 ,a sole-lea!r p\* ) %\ld] /rap conta9+-- #a sun mirror4 #a /ation mirror4 ,inclos$ 9 a wood5 box4 #a scre51 #a sight+ rod1 #a screw-driv]4 ,a small p\*1 slid+ by #b loops ^u ! /rap ( ! l>g] p\*1 conta9+ #a mirror b>4 ,a skeleton lea!r case conta9+ #b tripods4 ,illu/ration3 ,,fig4 #a4--;,heliograph assembl$4 ,! mirrors are ea* #d-;in* squ>es ( plate glass support$ by %eet brass & c>dbo>d back+s1 & m\nt$ 9 brass reta9+ frames4 ,at ! c5t] ( ea* mirror !re is an unsilv]$ spot ?ree ?irty-seconds ( an in* 9 diamet] & holes correspond+ to ^! spots are drill$ 9 ! back+4 ,! sun mirror diff]s f ! /ation mirror only 9 t x has a pap] disk pa/$ ^u its face cov]+ ! unsilv]$ spot4 ,! mirror frames are c>ri$ by brass supports provid$ at ! bases ) conical projections accurately turn$ to fit ! sockets ( ! mirror b> & groov$ at ! ends to receive ! clamp+ spr+4 ,ea* support is fitt$ ) a tang5t screw & worm :eel atta*m5t function$ to control ! motion ( ! mirror frame ab\t its horizontal axis4 ,illu/ration3 ,,fig4 #b4--,mirror & mirror b> case4 ,! mirror b> is a bronze ca/+ provid$ at ! c5t] ) a clamp ?read$ to fit ! screw ( ! tripod4 ,by releas+ ! clamp ! b> may be mov$ indep5d5tly ( ! screw & adju/$ to any desir$ position4 ,conical sockets = ! reception ( ! mirror supports are provid$ at ! ends ( ! mirror b>4 ,^! sockets "w freely 9 ! b> &1 be+ actuat$ by a tang5t screw & worm :eel1 s]ve to regulate ! motion ( ! mirror frame ab\t its v]tical axis4 ,clamp spr+s1 = engag+ & secur+ ! ends ( ! mirror frame supports1 are atta*$ at ea* end ( ! b>4 ,! scre5 is a brass frame #f in*es squ>e1 9 :i* six segm5ts or leaves are m\nt$ 9 su* a way z to =m a %utt]4 ,! leaves are design$ to turn ?r\gh arcs ( #ij on horizontal axes1 unanimity ( movem5t be+ secur$ by connections made ) a common crank b>4 ,! crank b> is op]at$ by a key & retractile spr+ :i* s]ve to reveal & cut (f ! fla%4 ,a set screw & *eck nut at ! l[] edge ( ! scre5 frame limits ! motion ( ! crank b> & ! op5+ ( ! leaves4 ,a ?read$ base support furni%es ! means ( atta*+ ! scre5 frame to ! tripod4 ,! sight+ rod is a brass rod #f in*es long1 c>ry+ at ! upp] end a front sight & a movable disk4 ,ab\t ! rod is fitt$ a movable bronze coll>1 con$ & groov$ to take ! socket & clamp+ spr+ ( ! mirror b>4 ,a mill$ edg$ bronze wa%] s]ves to clamp ! coll> to ! rod at any desir$ po9t4 ,illu/ration3 ,,fig4 #c4--;,heliograph tripods4 ,! tripods are simil> 9 all respects1 ! screw ( ei!r ?read+ into ! mirror b> or scre5 frame4 ,ea* tripod is provid$ ) a hook at ! base ( ! head1 all[+ ! susp5sion ( a weight :5 great /ability is requir$4 ,assembl+4--,!re are two ways ( assembl+ ! heliograph & ! position ( ! sun is ! guide 9 det]m9+ :i* ( ! two %\ld1 9 any giv5 case1 be employ$4 ,:5 ! sun is 9 front ( ! op]ator 7t is1 9 front ( a plane ?r\gh 8 position at "r angles to ! l9e jo9+ ! /ations7 ! sun mirror only is requir$2 ) ! sun 9 re> ( ?is plane bo? mirrors %\ld be us$4 ,) "o mirror ! rays ( ! sun are reflect$ directly f ! sun mirror to ! di/ant /ation2 ) two mirrors1 ! rays are reflect$ f ! sun mirror to ! /ation mirror1 & !nce to ! di/ant /ation4 ,) "o mirror3 ,firmly set "o ( ! tripods ^u ! gr\nd2 atta* ! mirror b> to ! tripod2 ins]t & clamp 9 ! sockets ! sun mirror & sight+ rod1 ! latt] hav+ ! disk turn$ d[n4 ,at a di/ance ( ab\t #f in*es1 sight ?r\gh ! c5t] ( ! unsilv]$ spot 9 ! mirror & turn ! mirror b>1 rais+ or l[]+ ! sight+ rod until ! c5t] ( ! mirror1 ! extreme po9t ( ! sight+ rod1 & ! di/ant /ation are accurately 9 l9e4 ,firmly clamp ! mirror b> to ! tripod1 tak+ c>e n to di/urb ! alignm5t1 & turn up ! disk ( ! sight+ rod4 ,! mirror is !n mov$ by means ( ! tang5t screws until ! %ad[ spot falls ^u ! pap] disk 9 ! sight+ rod1 aft] :i* ! fla% w be visible at ! di/ant /ation4 ,! %ad[ spot is readily f\nd by hold+ a %eet ( pap] or ! h& ab\t #f in*es 9 front ( ! mirror1 & %\ld be con/antly kept 9 view until locat$ ^u ! disk4 ,! scre5 is atta*$ to a tripod & e/abli%$ close to1 & 9 front (1 ! sight+ disk1 9 su* a way z to int]cept ! fla%4 ,) two mirrors3 ,firmly set "o ( ! tripods on ! gr\nd2 clamp ! mirror b> diagonally across ! l9e ( vision to ! di/ant /ation2 clamp ! sun mirror fac+ ! sun to "o end ( ! mirror b> & ! /ation mirror fac+ ! di/ant /ation4 ,/oop+ d[n1 ! head ne> & 9 re> ( ! /ation mirror1 turn ! sun mirror by means ( its tang5t screws until ! :ole ( ! /ation mirror is se5 reflect$ 9 ! sun mirror & ! unsilv]$ spot & ! reflection ( ! pap] disk accurately cov] ea* o!r4 ,/ill look+ into ! sun mirror1 adju/ ! /ation mirror by means ( ! tang5t screws until ! reflection ( ! di/ant /ation is br\ght exactly 9 l9e ) ! top ( ! reflection ( ! disk & ! top ( ! unsilv]$ spot ( ! sun mirror2 aft] ?is ! /ation mirror mu/ n be t\*$4 ,n[ /ep beh9d ! sun mirror & adju/ x by means ( ! tang5t screws s t ! %ad[ spot falls ^u ! c5t] ( ! pap] disk on ! /ation mirror4 ,! fla% w !n be visible at ! di/ant /ation4 ,! scre5 & its tripod are e/abli%$ z describ$ 9 ! s+le mirror assembl+4 ,alt]nate me?od ) two mirrors3 ,clamp ! mirror b> diagonally across ! l9e ( vision to ! di/ant /ation1 ) ! sun mirror & ! /ation mirror approximately fac+ ! sun & di/ant /ation1 respectively4 ,look ?r\gh small hole 9 sun mirror & turn ! /ation mirror on its v]tical & horizontal axes until ! pap] disk on ! /ation mirror accurately cov]s ! di/ant /ation4 ,/&+ beh9d sun mirror1 turn x on its horizontal & v]tical axes by means ( ! tang5t screw atta*m5ts until ! %ad[ spot falls ^u ! pap] disk on /ation mirror4 ,adju/m5t4--,p]fect adju/m5t is ma9ta9$ only by keep+ ! %ad[ spot un9t]rupt$ly 9 ! c5t] ( ! pap] disk1 & z ?is spot cont9ually *anges its position ) ! app>5t movem5t ( ! sun1 "o signalman %\ld be 9 con/ant att5dance on ! tang5t screws ( ! sun mirror4 ,movem5t imp>t$ by ^! screws to ! mirror does n di/urb ! alignm5t1 z its c5t] 7! unsilv]$ spot7 is at ! int]section ( ! axes ( revolution4 ,extra c>e be/[$ ^u prelim9>y adju/m5t is repaid by increas$ brilliancy ( fla%4 ,) ! alignm5t absolutely assur$ & ! %ad[ spot at ! c5t] ( ! disk1 ! axis ( ! cone ( reflect$ rays is co9cid5t ) ! l9e ( sight & ! di/ant /ation receives ! greate/ int5sity ( light4 ,rememb] ! di/ant obs]v] is unque/ionably ! bett] judge z to ! "* ( ! fla% receiv$2 & if !re=e1 adju/m5t is call$ = :5 ! %ad[ spot is at ! c5t] ( ! disk1 ! alignm5t is probably at fault & %\ld be look$ aft] at once4 ,9 sett+ up ! tripods always see t ! legs h a suffici5t spread to give a secure base & on yield+ soil press firmly into ! gr\nd4 ,keep ! head ( ! tripod z ne>ly level z possible & 9 high w9d balla/ by hang+ a sub/antial weight to ! hook4 ,see t ! scre5 completely obscures ! fla%2 also t ! fla% passes entire :5 ! scre5 is op5$4 ,?is feature ( ! adju/m5t is p>tially regulat$ by ! set screw atta*$ to ! scre5 frame4 ,! retractile spr+ %\ld %>ply return all ! leaves ( ! scre5 to _! normal positions :5 ! key is releas$4 ,failure to respond promptly is obviat$ by /r5g!n+ or replac+ ! spr+4 ,op]ation4--,x is ( ! utmo/ importance t uni=mity 9 me*anical movem5t ( ! scre5 be cultivat$1 z lack ( rhy?m 9 ! signals ( ! s5d] entails breaks & delay on ! "p ( ! receiv]4 ,d>k backgr\nds %\ld1 :5 practicable1 be select$ = heliograph /ations1 z ! signals c be mo/ easily di/+ui%$ aga9/ !m4 ,to f9d a di/ant /ation1 its position be+ unkn[n1 rev]se ! cat* hold+ ! /ation mirror & ) ! h& turn ! mirror v sl[ly at ! horizon ov] ! full azimu? di/ance 9 :i* ! di/ant /ation may possibly lie4 ,?is %\ld be repeat$ n less ?an twice1 aft] :i*1 )9 a reasonable "t1 !re be+ no response1 ! mirror w be direct$ ^u a po9t ne>] ! home /ation & ! same process repeat$4 ,) c>e & intellig5ce x is q probable t1 a /ation be+ )9 range & wat*+ = signals f a di/ant /ation ) :i* x may be desir$ to ex*ange messages1 ?is me?od w r>ely fail to f9d ! s\ght-= /ation4 ,! exact direction ( ei!r /ation se>*+ = ! o!r be+ unkn[n1 t /ation :i* fir/ p]ceives t x is be+ call$ w adju/ its fla% ^u ! di/ant /ation to enable x :5 ?is light is obs]v$ to make prop] adju/m5ts4 ,if ! position ( ea* /ation is kn[n to ! o!r1 ! /ation fir/ ready = signal+ w direct a /eady fla% ^u ! di/ant /ation to enable ! latt] to see n only t ! fir/ /ation is ready = "w1 b to enable ! di/ant /ation to adju/ its fla% ^u ! fir/ /ation4 ,smok$ or color$ glasses are issu$ = ! purpose ( reliev+ ! /ra9 on ! eyes produc$ by read+ heliograph signals4 ,c>e ( app>atus4--,m9or p>ts ( ! in/rum5t %\ld be dism\nt$ only to effect repairs1 = :i* sp>e p>ts are furni%$ on requisition4 ,/eel p>ts %\ld be kept oil$ & free f ru/4 ,tang5t screws & be>+s %\ld be frequ5tly inspect$ = du/ or grit4 ,mirrors %\ld inv>iably be wip$ clean be=e us+4 ,9 case ( accid5t to ! sun mirror1 ! /ation mirror c be made available = sub/itution !re= by remov+ ! pap] disk4 ,if ! tripod legs become loose at ! head jo9ts1 tight5 ! assembl+ screws ) ! screw-driv]4 ,p[]s & limitations ( ! heliograph4--,portability1 great range1 comp>ative rapidity ( op]ation1 & ! invisibility ( ! signals except to obs]v]s locat$ approximately on a "r l9e jo9+ ! /ations betwe5 :i* communication is _h1 are "s ( ! advantages d]iv$ f us+ ! heliograph 9 visual signal+4 ,! pr9cipal disadvantage results f ! entire dep5d5ce ( ! in/rum5t ^u ! pres5ce ( sunlight4 ,! normal work+ range ( ! heliograph is ab\t #cj miles1 ?\gh in/ances ( its hav+ atta9$ ranges _m times great] ?an ?is are ( record4 ,! heliograph c be dep5d$ ^u to transmit f five to twelve words p] m9ute4 ,,! ,,acetyl5e ,,lant]n4 ,! signal lant]n is an in/rum5t design$ = ! purpose ( transmitt+ signals by means ( int]mitt5t fla%es ( artificial light4 ,x is ! /&>d night visual signal+ equipm5t furni%$ by ! ,signal ,corps & dep5ds = its illum9ation ^u ! combu/ion ( acetyl5e gas4 ,acetyl5e4--,acetyl5e is a pure hydroc>bon gas1 producible 9 v>i\s ways1 ! common] ( :i* are3 7a7 ,by dropp+ calcium c>bide into wat]2 7b7 by dropp+ wat] ^u calcium c>bide4 ,?is gas gives1 :5 burn+1 high p5etrative p[]1 & 0 fir/ describ$ by ,mr4 ,edmund ,davy1 pr(essor ( *emi/ry to ! ,royal ,dubl9 ,society1 9 #ahcf4 ,calcium c>bide4--,9 ! manufacture ( calcium c>bide = comm]cial purposes ! be/ quality ( coke & quicklime are us$4 ,^! two sub/ances are p[d]$ ?or\ghly1 mix$ 9 prop] proportions1 & !n plac$ 9 an electrical furnace4 ,"u ! action ( ! int5se heat 7#e1ejj ,f47 ^! two refractory sub/ances unite & =m calcium c>bide4 ,calcium c>bide is ( a grayi%-:ite color1 cry/al 9 appe>ance1 & is nonexplosive & noncombu/ible1 be+1 except = its aff9ity = wat]1 an absolutely in]t sub/ance4 ,a p\nd ( comm]cial c>bide w produce approximately #e cubic feet ( gas4 ,:5 wat] is br\ght 9 contact ) calcium c>bide1 ! g5]ation ( acetyl5e is rapid2 ow+ to its /rong aff9ity = wat] x w become air slack$ & sl[ly lose its /r5g? if expos$ to ! action ( ! moi/ure 9 ! atmosph]e2 consequ5tly1 :5 /or$ or be+ transport$ x %\ld be kept 9 air-tight cans4 ,:5 calcium c>bide is br\ght 9 contact ) wat]1 ! foll[+ occurs3 ,z is kn[n1 ! pr9cipal compon5ts ( wat] are oxyg5 & hydrog51 & calcium c>bide is calcium & c>bon4 ,:5 br\ght 9 contact1 ! oxyg5 9 ! wat] decomposes ! calcium 9 ! c>bide1 & 9 ?is decomposition ! hydrog5 9 ! wat] is lib]at$ & unites ) ! c>bon ( ! c>bide1 =m+ a hydroc>bon gas :i* is acetyl5e4 ,x is a pure :ite light ( int5se brilliancy & high c&lep[]4 ,! spectrum analysis ( acetyl5e %[s t x is almo/ id5tical ) sunlight1 & 9 consequ5ce delicate %ades ( color appe> accord+ to _! true value z "u ! light ( ! sun1 consequ5tly x p5etrates fog to a great] di/ance ?an o!r lights4 ,acetyl5e is l o!r gases--explosive :5 mix$ ) air 9 prop] proportions1 conf9$1 & ignit$--& ! same precautions %\ld !re=e be tak5 9 its use z w\ld be 9 ! h&l+ ( coal or wat] gas1 gasol9e vapor1 etc4 ,z acetyl5e is v ri* 9 c>bon1 x w n burn 9 its pure /ate )\t smok+4 ,to avoid ?is1 burn]s h be5 con/ruct$ s t ! gas is mix$ ) ! prop] proportion ( air at ! burn] tip1 to insure p]fect combu/ion4 ,! burn]s = acetyl5e are diff]5t f ^? = o!r gases4 ,9 ord] to get a flat flame1 ! gas is br\ght ?r\gh two p]fectly r\nd holes at an angle :i* causes ! two flames to imp+e ^u ea* o!r & ?us =m a flat flame4 ,me?od ( gas g5]ation4--,! me?od employ$ = produc+ acetyl5e 9 ! signal lant]n is by br++ wat] into contact ) calcium c>bide4 ,! disadvantage ( ?is me?od is t :5 ! wat] is n 9 excess & does n entirely surr\nd & t\* ea* piece ( c>bide ! heat ( g5]ation w s *ange ! *emical prop]ties ( ! gas t combu/ion at ! burn]s is n satisfactory4 ,?is *ange is te*nically kn[n z polym]ization1 or ! break+ up ( acetyl5e into o!r hydroc>bons1 su* z vapors ( b5z9e1 b5zole1 etc4 ,^! =m a t>ry sub/ance :i* is apt to cond5se at ! burn] tip & clog ! op5+s4 ,also !y deposit c>bon on ! burn]s1 z !y require m air = p]fect combu/ion ?an does pure acetyl5e4 ,ano!r disadvantage ( ?is sy/em is t aft] ! c>bide & wat] are 9 contact1 g5]ation ( gas w cont9ue until all ! wat] is absorb$4 ,:]e1 h[ev]1 portability ( ! g5]at+ app>atus is desir$ & resort to ?is me?od is necess>y1 ! objections are n important1 if ! app>atus is well con/ruct$ & c>e is tak5 9 its use4 ,description4--,?is equipm5t consi/s ( a signal lant]n ) c>tridge g5]ator atta*$4 ,! lant]n is equipp$ ) a special aplanatic l5s mirror1 #e in*es 9 diamet] & ab\t #c in*es focus4 ,! lant]n is pack$ complete 9 a wood5 case ) %\ld] /raps & ! foll[+ extra p>ts are includ$1 ea* "p hav+ its own receptacle 9 ! case3 #b burn]s2 #a cov] glass2 #c c>tridges ( calcium c>bide ( #e ounces ea*2 #a pair ( gas pli]s2 #a tube :ite lead2 #a extra filt] bag2 #a screw-driv]4 ,illu/ration3 ,,fig4 #d4--,! signal lant]n4 ,! lant]n is made ( brass1 all p>ts ( :i* are rivet$4 ,! burn] is ( ! d\ble tip =m1 consum+ ?ree-qu>t]s ( a cubic foot p] h\r4 ,! lant]n is fitt$ ) a hood to provide prop] v5tilation & at ! same "t to prev5t ! flick]+ ( ! light by ! w9d4 ,! front door ( ! lant]n is h+$ & fa/5s ) a spr+ clasp2 x is s arrang$ t x c be entirely remov$ if necess>y4 ,! cov] glass is made 9 ?ree sections & is n affect$ by ! expansion & contraction ( ! metal due to *anges 9 temp]ature4 ,! glass is fa/5$ by ! aid ( a spr+ wire1 s t x c be readily remov$ if x is necess>y to replace a brok5 section4 ,9 ! base ( ! lant]n is a key & ! adju/m5t = regulat+ ! height ( ! flame4 ,! key is s arrang$ t :5 n depress$ b little gas is admitt$ ?r\gh ! by-pass to ! burn] & ! flame is l[4 ,by depress+ ! key z mu* gas z c be entirely consum$ is admitt$ to ! burn]1 :i* gives a bright fla%4 ,at ! back ( ! lant]n !re is an adju/able h&le1 s t ! equipm5t c be us$ z a h& lant]n if desir$4 ,?is =m ( lant]n c be us$ ) ! regul> heliograph tripod1 ! g5]ator be+ ei!r atta*$ to ! back ( ! lant]n or susp5d$1 z %[n 9 figure #d4 ,:5 practicable x is bett] to atta* ! g5]ator to ! lant]n1 z %[n 9 figure #e4 ,! c&lep[] ( ?is lant]n is ab\t #a1ijj4 ,illu/ration3 ,,fig4 #e4 ,! g5]ator us$ is kn[n z ! c>tridge g5]ator1 & :ile con/ruct$ on ! wat]-fe$ pr9ciple1 ! disadvantages incid5t to ?is me?od are elim9at$ z f> z possible4 ,x is con/ruct$ ( brass & has a removable top4 ,atta*$ to ! inside ( ! top is a flexible frame ) a spr+ lat*1 ! spr+ lat* be+ h+$4 7,fig4 #h47 ,at ! top ( ! frame is a tube or cyl9d]1 ! bottom ( :i* is conical 9 %ape & cov]$ by a rubb] plug4 ,at ! bottom ( ! frame is a holl[ tube1 :i* is ! wat] inlet4 ,! c>tridge prop] consi/s ( a t9 cyl9d]1 hav+ an op5+ at ei!r end4 ,a small cyl9d] ( wire me% ext5ds f & connects ^! op5+s4 ,! c>bide lays ar\nd ?is me% on ! inside ( ! c>tridge4 ,! rubb] plug be=e m5tion$ fits into ! upp] op5+1 & ! wat] tube into ! l[] op5+4 7,see figs4 #g1 #h1 & #i47 ,inside ! tube1 at ! top ( ! frame1 is a filt]1 ! function ( :i* is to remove ! du/ & moi/ure f ! gas4 ,! outlet f ?is *amb] is by a brass b5t tube hav+ a /opcock atta*$ !reto4 ,figure #f gives a sectional view ( ! g5]ator ) ! c>tridge 9 place4 ,d ,f ,g ,h repres5t ! valve frame & ,i ! c>tridge atta*$4 ,! res]voir ,a is fill$ ) wat]1 & :5 ! frame is imm]s$1 ) ! valve ,r clos$1 ! air conta9$ 9 ! c>tridge & tub+ c n escape1 ! wat] seal prev5t+1 :ile ! conf9$ air prev5ts ! wat] f ris+ 9 ! tube ,n4 ,:5 ! valve at ,r is op5$ & ! air is all[$ to escape1 "p ( ! wat] f ! res]voir rises into ! tube ,n & !n out ?r\gh ! small hole ,o to ! c>bide4 ,gas is imm$iately g5]at$1 ! pressure ( :i* prev5ts fur!r +ress ( ! wat] f ! tube ,n1 & ! g5]ation ( gas is susp5d$4 ,z ! gas passes out ?r\gh ! valve at ,r ! pressure decreases1 p]mitt+ ! wat] to aga9 rise 9 ! tube & fl[ ?r\gh ,o4 ,gas is aga9 g5]at$1 :i* at once ex]ts its pressure & cuts (f ! supply ( wat]4 ,?is is ! automatic action by :i* wat] is br\ght 9 contact ) ! calcium c>bide4 ,?us x w be obs]v$ t ! use or escape ( ! gas regulates ! g5]ation by ! simple device ( ! rise & fall ( a wat] column4 ,!re is a cap ,m screw$ ov] ! tube ,n4 ,?is is us$ to deflect ! c\rse ( ! wat] d[nw>d1 s t ! c>bide 9 ! l[] "p ( ! c>tridge is fir/ attack$4 ,!re is a ne$le inside ( cap ,m1 :i* c be us$ = clean+ ! hole ,o4 ,:5 ! gas is g5]at$ x passes ?r\gh ! filt] ,d on its way to ! burn] ?r\gh ,r4 ,?is filt] consi/s ( a tube loosely pack$ ) ord9>y nonabsorb5t cotton1 :i* %\ld nev] cov] ! escape pipe lead+ to ! valve ,r4 ,9 pass+ ?r\gh ?is cotton filt] moi/ure & du/ are remov$ f ! gas4 ,9 ! late/ model a felt filt] is us$ in/ead ( cotton4 ,illu/ration3 ,,fig4 #f4--,signal lant]n g5]ator4 ,! escape pipe ,f provides a means = ! escape ( gas g5]at$ & n us$ or g5]at$ m rapidly ?an consum$4 ,%\ld an excess be g5]at$1 x passes d[n ?r\gh ! tube ,f1 &1 f9d+ its way ?r\gh "s small holes 9 ! bottom ( ?is tube1 escapes ?r\gh ! wat] seal & ! op5+ at ,c4 ,x w be not$ t if escap+ gas at ,c %\ld become accid5tally light$1 ! flame c n /rike back into ! filt] & c>tridge because ( ! wat] seal4 ,! pr9cipal ?+s to obs]ve 9 ! op]ation ( ?is g5]ator are ! foll[+3 7#a7 ,to see t ! rubb] plugs fit tightly into ! op5+s ( ! c>tridge4 7#b7 ,t ! tube ,n1 ! cap ,m1 & wat] hole ,o are n /opp$ up4 7#c7 ,t ! cotton 9 ! filt] is *ang$ frequ5tly4 7#d7 ,t ! /opcock ,r is clos$ be=e ins]t+ ! frame 9 ! wat]4 ,if ?is latt] in/ruction is n compli$ )1 x c be readily se5 t ! wat] w h free access to ! c>bide & excessive g5]ation w occur4 ,:5 ! *>ge is exhau/$1 ! entire c>tridge is tak5 out & ?r[n away4 ,?is elim9ates ! h&l+ ( c>bide & ! disagreeable task ( clean+ out ! residuum aft] ! gas has be5 extract$4 ,connection is made f ! /opcock ,r to ! hose connection on ! lant]n prop]1 & ?is is ! passageway ( ! gas f ! g5]ator to ! burn]4 ,z soon z ! /opcock is op5$ ! wat] rises ?r\gh ! tube & fl[s to ! c>bide4 ,! advantage ( ! c>tridge be+ subm]g$ 9 ! wat] is to r$uce & absorb z mu* ( ! heat lib]at$ by g5]ation z is possible4 ,^! lant]ns h be5 te/$ up to a di/ance ( #aj miles ) ! nak$ eye1 & "u favorable conditions c be us$ ov] a range some:at 9 excess ( ?is4 ,) a #cj-p[] telescope ! fla% c be read at a di/ance ( #cj miles4 ,op]ation & c>e4--,take ! lamp & g5]ator f ! case by aid ( ! h&le atta*$ to ! lamp2 screw ! complete outfit on a heliograph tripod1 or /& ! outfit on a level object2 remove ! cov] ( g5]ator1 to :i* is atta*$ ! flexible frame 7fig4 #i72 deta* spr+ f ! cat* ( ! flexible frame2 te> (f flaps f ! ends ( c>bide c>tridge 7or pry (f small caps7 & atta* ! c>tridge z %[n 9 figure #i4 ,!n atta* to frame z %[n 9 figure #aj1 be+ c>eful to see t bo? rubb] plugs fit tightly into ! holes 9 ! c>tridge2 fa/5 ! lat* ( ! spr+ ov] ! metal cat*2 close /opcock ,r on s]vice pipe2 completely fill ! out] c ( g5]ator ) wat]1 ! object be+ to h ! g5]ator level full ( wat] :5 ! lamp is 9 s]vice1 !n imm]se ! frame & c>tridge1 press+ ! top ( ! g5]ator d[n tight4 ,9 do+ ?is ! wat] w ov]fl[ ! sides ( ! g5]ator tank4 ,n[ connect by rubb] tub+ ! /opcock ) ! gas inlet at ! bottom ( ! lamps1 z %[n 9 figure #d2 !n 7#a7 op5 front door ( ! lamp1 7#b7 light a mat*1 7#c7 op5 /opcock1 & 7#d7 light ! gas at ! burn]4 ,9 do+ ?is hold ! key op54 ,9 ! new model ! key & hose connection are on ! side ( bottom ( lamp4 ,:5 ! gas is ignit$1 ! lamp is ready = signal+1 & ! key c be op]at$ z is ! ,morse telegraph in/rum5t1 b ( c\rse n s rapidly4 ,9 ! ev5t ( ! flame be+ too high :5 ! key is clos$1 adju/m5t c be made by loos5+ ! set screw 7fig4 #d1 indicat$ by an arr[7 & adju/+ ! light by turn+ screw b4 ,:5 at ! prop] height1 tight5 ! set screw :i* locks ! by-pass 9 its prop] position4 ,9 ! new model ?is is accompli%$ by aid ( ! regulator by-pass valve at ! left-h& side ( bottom ( lamp4 ,! lamp is prop]ly adju/$ :5 %ipp$ & %\ld n be *ang$ unless absolutely necess>y4 ,connect ! rubb] tube to ! burn] be=e op5+ ! /opcock on ! g5]ator4 ,to re*>ge ! g5]ator1 take ! frame & ! old c>tridge f ! case1 ?r[ away ! old case & replace ) a fre% "o1 proce$+ z be=e4 ,see t fre% wat] is put 9 ! g5]ator ea* "t a new c>tridge is us$4 ,illu/ration3 ,,fig4 #g4 ,9 ! tube ?r\gh :i* ! s]vice pipe passes is a felt filt] = tak+ ! du/ out ( ! gas4 ,if ! filt] clogs1 unscrew ! cap to :i* ! s]vice pipe is atta*$1 clean ! felt1 or replace x ) a new filt]1 b9d+ x 9 place by a /\t ?read or /r+4 ,if ! burn] ( ! lamp does n produce a p]fectly flat flame x has become clogg$ & %\ld be clean$ ) ! burn] clean] furni%$1 or a new burn] %\ld be sub/itut$1 c>e be+ tak5 to put a little :ite lead on ! nipple1 if practicable1 s z to insure a tight jo9t4 ,9 repack+ ! outfit 9 ! case1 ?r[ out ! wat] & wipe ! c & g5]ator p>ts dry4 ,y c n be too c>eful to keep ! app>atus clean4 ,?is is especially true ( ! small pipe t passes up ?r\gh ! bottom ( ! c>tridge1 ) a cap ov] x4 ,! cap %\ld always be screw$ 9 place1 z its object is to prev5t ! wat] f squirt+ to ! top ( ! c>tridge4 ,illu/ration3 ,,fig4 #h4 ,illu/ration3 ,,fig4 #i4 ,! back ( ! lamp c be remov$ by turn+ ! small ?umbscrew on ! top & draw+ out ! p9 :i* holds ! %ell into :i* is fitt$ ! l5s4 ,x is n necess>y to take ! back out except to replace a l5s1 z ! latt] c be clean$ by op5+ ! front door4 ,if x is desirable to use ! lamp z a h& lant]n ! flame c be turn$ on full by turn+ ! button 9 a v]tical position2 ?is locks ! key op54 ,9 ! new model depress ! key & lock x ) ! lat* above ! key4 ,"o *>ge ( calcium c>bide w supply gas to burn ab\t "o h\r ) ! light turn$ on full1 or = approximately ?ree h\rs' signal+4 ,illu/ration3 ,,fig4 #aj4 ,if signal+ is to be susp5d$ = "s h\rs1 empty ! wat] out ( ! g5]ator & close valve ,r4 ,! glass front c be replac$ by tak+ out ! wire spr+4 ,! glass cuts %\ld be m\nt$ 9 a horizontal position &1 to prev5t break+1 %\ld be protect$ f ra9 :5 ! lamp is hot4 ,if a glass %\ld be brok5 & an extra "o is n available to replace x1 signal+ c be cont9u$ by turn+ ! flame on full & us+ ! heliograph %utt]1 a cap or piece ( bo>d 9 front ( ! lant]n to obscure & reveal ! fla%4 ,)\t ! protection ( ! cov] ! flame is easily bl[n out :5 turn$ l[1 b w n be ext+ui%$ ev5 9 a /rong w9d if ! gas is turn$ full on4 ,old model lamps are s]ially numb]$ f #a to #bjj1 inclusive2 ! new model lamps are s]ially numb]$ f #bja upw>d4 ,p[]s & limitations ( ! acetyl5e signal lant]n4--,z conditions are usually m uni=m at night ?an 9 ! daytime1 ! signal lant]n is probably ! mo/ reliable ( all visual signal+ outfits4 ,! advantages ( ?is =m ( app>atus are its portability1 spe$ ( op]ation1 & comp>atively great range4 ,! pr9cipal disadvantages are due to ! int]f]5ce caus$ by ra91 fog1 & moonlight4 ,! spe$ atta9able ) ! lant]n is ab\t ! same z t atta9able ) ! heliograph4 ,,rockets ,,& ,,%ells4 ,two di/9ct k9ds ( rockets & %ells are issu$1 "o ( :i* is adapt$ to day & ! o!r to night signal+4 ,%ells & rockets ( ! amb] smoke type ) p>a*utes are us$ 9 ! daytime1 :ile %ells 7r$ & :ite7 & sequ5ce rockets are us$ at night4 ,illu/ration3 ,,fig4 #aa4--,signal+ rocket & accessories4 ,illu/ration3 ,,fig4 #ab4--,signal+ %ells4 ,description4--,! %ells are all s+le %ot & are fir$ f a #e-;in* portable mort>1 atta9+ a height ( ab\t #eej feet4 ,! report ( explosion c be he>d at v>y+ di/ances up to #e miles1 dep5d+ on wea!r conditions4 ,! p>a*ute atta*$ to ! smoke %ell susp5ds a small light wood5 tube :i*1 aft] ignition1 emits smoke = f f\r to six seconds4 ,! r$ & :ite %ells1 on bur/+1 dis*>ge a %[] ( r$ & :ite fire :i* c be obs]v$ = "s "t1 9 fact almo/ until ! sp>ks fall to ! gr\nd4 ,rockets = bo? day & night signal+ are equipp$ ) p>a*utes4 ,! smoke rocket is ( simil> con/ruction to ! smoke %ell4 ,! sequ5ce rocket is s arrang$ at ! base t ?read$ sections ( combu/ible mat]ial burn+ ei!r r$ or :ite c be atta*$ to x4 ,rockets asc5d ab\t #gjj feet4 ,ea* rocket & %ell is suppli$ 9 a cyl9drical seal$ t9 c1 :i* also conta9s a port fire1 w9d mat*es1 & = ! rockets a /ick 9 f\r sections4 ,on ! outside ( ! c is a label designat+ ! k9d ( %ell or rocket !re9 conta9$4 ,^! cans are easily op5$ by pull+ a r+ & require no special op5+ tool4 ,op]ation4--,9 fir+ %ells ! mort> %\ld be surr\nd$ by e>? or s&1 pref]ably plac$ 9 sacks4 ,! fuse = all %ells is v rapid & %\ld be ignit$ by atta*+ ! port fire to a long /ick4 ,all ( ! old type ,signal ,corps mort>s1 orig9ally design$ to )/& a pressure ( #a1jjj p\nds p] squ>e in*1 & made ( ord9>y iron pipe1 are consid]$ unsafe & %\ld be imm$iately de/roy$4 ,! new mort>s1 rec5tly made = ! ,signal ,corps by ! ,ordnance ,dep>tm5t1 are ( cold-drawn /eel hav+ a t5sile /r5g? ( #f1jjj p\nds p] squ>e in*1 :i* is m ?an ! maximum pressure = fir+ any ( ! ,signal ,corps bombs4 ,!y are /amp$ ,signal ,corps1 ,u4 ,s4 ,a41 ,model #aijg1 or ,rocket ,gun1 ,wat]t[n ,ars5al1 #aijg4 ,! sequ5ce rocket is prep>$ = use by atta*+ r$ or :ite sections to ! base 9 su* a comb9ation z to =m lett]s ( ! alphabet :i* x is desir$ to use4 ,lett]s conta9+ ! same color 9 sequ5ce are v difficult to read & %\ld be avoid$ :5ev] possible4 ,if necess>y to use !m1 blank sections furni%$ = ! purpose %\ld be ins]t$ betwe5 ! units4 ,! base ( ! rocket w secure six units4 ,:5 rockets are to be fir$ ! /icks mu/ be firmly atta*$1 ! rocket plac$ upright 9 a tr\gh1 ^u a frame1 or aga9/ a po/4 ,if ! fuse is b5ea? ! pap] cov]+ ! *oke orifice1 ! pap] %\ld be torn (f & ! rocket ignit$ by a port fire4 ,9 ! rockets n[ us$ ! fuse ext5ds ?r\gh ! cov]+ & c be light$ direct4 ,if ! night be damp ?is fuse %\ld be expos$ only a mom5t be=e ! rocket is fir$4 ,if sev]al rockets are to be fir$ 9 succession x is well to prep>e !m all at ! same "t1 & to h !m all /ood upright1 b ea* sep>at$ f ! o!r at a di/ance ( at lea/ #f feet1 else "o may ignite ! o!r accid5tally4 ,9 fir+ = *ronosemic signals1 "o rocket ought to be kept ready ^u ! frame & 9 res]ve1 to be fir$ 9 place ( "o t fails4 ,if a rocket misses fire x is to be tak5 f ! /& & laid on ! gr\nd4 ,its place is at once suppli$ by a simil> rocket1 fir$ 9 its /ead4 ,! fail+ rocket is laid on ! gr\nd po9t$ away f ! /ation 9 ord] t if x has only hung fire & %\ld aft]w>ds ignite x may n dis>range ! signal %[n or injure any "o ( ! p>ty4 ,if ! w9d bl[s fre%ly ! rocket to be fir$ %\ld be incl9$ slightly aga9/ ! w9d4 ,signal rockets & %ells are furni%$ 9 seal$ cans & %\ld n be remov$ !refrom until ready = use4 ,/rict economy %\ld be obs]v$ 9 ! use ( ^! articles & on no acc\nt %\ld !y be us$ = purposes ( display4 ,employm5t4--,rockets & %ells are especially valuable 9 mak+ preconc]t$ or em]g5cy signals4 ,on acc\nt ( ! great am\nt ( ammunition requir$ x is impracticable to spell out messages ) !m4 ,^! articles %\ld be suppli$ to outpo/s1 deta*$ /ations1 etc41 to be us$ = signal+ ! approa* ( ! enemy or ! happ5+ ( unexpect$ ev5ts1 ! necessity = promptly kn[+ :i* is important4 ,,! ,,semaphore4 ,if signal /ations are to be p]man5tly occupi$1 & x is impracticable to electrically connect !m1 communication may be facilitat$ by erect+ semaphores4 ,semaphores1 :ile prim>ily us$ = day signal+1 c be advantage\sly us$ at night by atta*+ lights to ! arms4 ,! navy semaphore consi/s ( f\r arms pivot$ at ! ends1 ?ree on "o side ( ! upright1 or pole1 & "o on ! o!r side4 ,^! arms h ?ree positions3 ,horizontal2 upw>d at an angle ( #de to ! horizontal2 d[nw>d at an angle ( #de to ! horizontal4 ,full in/ructions = ! op]ation ( ! semaphore1 & also = ! use ( balls1 cones1 drums1 p5nants1 & :efts z di/ant signals1 are giv5 9 ! ,int]national ,code ( ,signals4 ,,! ,,se>*light4 ,! electric se>*light1 :5 available1 c (t5 be successfully employ$ = night signal+1 frequ5tly af=d+ effici5t means ( communication betwe5 %ips & %ore /ations1 :5 wireless work+ is impracticable4 ,?is sy/em ( visual signal+ is practicable & especially valuable :]e ! /ations are1 on acc\nt ( ! t]ra91 n int]visible4 ,me?ods ( employm5t4--,9 signal+ ) ! se>*light ! usual me?od ( h&l+ ! %aft or beam is id5tical ) t employ$ ) ! flag4 ,9 ! fir/ position ! beam is %[n v]tically1 :ile motions to ! "r1 ! left1 & directly s]ve to indicate ! elem5ts ( ! alphabet4 ,*ronosemic signals may also be us$ 9 se>*light signal+1 ! %aft ( light be+ direct$ int]mitt5tly on "s conspicu\s object1 su* z a cl\d1 balloon1 or high m\nta9 top4 ,,co/on ,,signals4 ,^! signals are pyrote*nic compositions :i* burn ) great int5sity ( light & color4 ,! colors r$1 :ite1 & gre5 are f\nd be/ suit$ = signal+4 ,! signals are prep>$ 9 ! =m ( c>tridges & are burn$ f a hold]4 ,! colors burn$ may indicate ! elem5ts ( any alphabet1 or su* o!r special signals z may be desir$4 ,,v',s ,,night ,,signals4 ,! ,v sy/em employs project$ r$1 :ite1 & gre5 />s1 :i* are %ot f pi/ols held 9 ! h&4 ,description4--,! ,v pi/ol is a bree*load+1 s+le-%ot pi/ol ) an #h-;in* /eel b>rel *amb]$ to receive a #ab-;gauge comm]cial %otgun %ell4 ,brass %ells are us$ & are pack$ 9 boxes color$ to indicate ! "* ( />s employ$ 9 load+4 ,! color ( ! /> fir$ may indicate an elem5t ( any alphabet or any special signal :i* may be desir$4 ,! />s rise to a height ( ab\t #bjj feet & rema9 visible = "s "t4 ,,! ,,ardois ,,sy/em4 ,! ,ardois sy/em is a special sy/em ( night signal+ design$ to utilize comb9ations ( r$ & :ite signal lights 9 =m+ ! elem5ts ( any desir$ alphabet4 ,f\r signal lamps capable ( display+ ei!r r$ or :ite lights are atta*$ at conv5i5t int]vals to a v]tical cable or /aff rigg$ betwe5 ! top ( a ma/ & ! deck1 if on %ipbo>d1 or ! gr\nd1 if on %ore4 ,illum9ation is furni%$ by electrical means & any desir$ comb9ation ( lights is automatically obta9able by op]at+ a keybo>d4 ,?is sy/em is valuable on vessels or at p]man5t %ore /ations1 b ! great exp5se ( in/allation precludes its g5]al use4 ,wir+ diagrams & te*nical in/ructions relative to ?is app>atus are 9 all cases furni%$ :5 ! same is issu$4 ,illu/ration3 ,,fig4 #ac4--,! ,v pi/ol4 ,,s\nd ,,signals4 ,:5 rec\rse to any me?od ( sight signals c n be _h on acc\nt ( wea!r conditions or lack ( suitable app>atus1 s\nd signals may (t5 be advantage\sly us$4 ,! common] means ( furni%+ s\nd signals are ! horn & ! :i/le1 ?\gh _m o!r k9ds ( app>atus are practicable4 ,! necess>y elem5ts ( any sy/em c be indicat$ by "o %ort1 two %orts1 & a long bla/4 ,! advantage ( ?is sy/em ( signal+ is t x c be us$ 9 any k9d ( wea!r1 bo? 9 daytime & at night4 ,on ! o!r h&1 s\nd signals are g5]ally m difficult to read ?an sight signals & t5d to disclose ! pres5ce ( /ations to ho/ile =ces4 ,,improvis$ ,,signal+ ,,me?ods4 ,! object ( ?is *apt] has be5 to describe only ! /&>d visual signal+ equipm5t issu$ & g5]ally utiliz$4 ,besides ! me?ods detail$1 !re are _m o!rs :i* may be successfully employ$ by ! +5i\s signalman :5 ! necessity = !m arise4 ,! use ( any means ( transmitt+ signals :atev] is ju/ifiable :5 = any reason ! regul> app>atus is n available4 ,special conv5tional sc\t signals are giv5 9 p>agraph #hb1 ,field ,s]vice ,regulations4 ,9 ! field _m in/ances w occur :]e x w be necess>y to transmit in=mation rapidly )\t rec\rse to ! au?oriz$ equipm5t4 ,?is w be especially true ( outpo/s1 deta*$ /ations1 patrols1 & o!r small bodies ( troops1 & x w devolve ^u individual comm&]s to improvise me?ods ( signal+ be/ suit$ to ! occasion & ! conv5i5ces at h&4 ,,*apt] ,,iii4 ,,alphabets ,,or ,,sy/ems ,,( ,,signals4 ,,signal ,,alphabets4 ,,am]ican ,,cont95tal ,,army ,,& ,lett]s-- ,,morse4 ,,morse4 ,,navy4 ,a -- -- #bb ,b -- -- #baab ,c -- -- #aba ,d -- -- #bbb ,e #ab ,f -- -- #bbba ,g -- -- -- -- #bbaa ,h #abb ,i #a ,j -- -- -- -- -- #aabb ,k -- -- -- -- #baba ,l ---- -- #bba ,m -- -- -- -- #abba ,n -- -- #aa ,o -- -- -- #ba ,p -- -- #abab ,q -- -- -- -- #abaa ,r -- #baa ,s #bab ,t -- -- #b ,u -- -- #aab ,v -- -- #abbb ,w -- -- -- -- #aaba ,x -- -- -- #babb ,y -- -- -- #aaa ,z -- -- #bbbb tion #aaab ,num]als-- ,,am]ican ,,cont95tal ,,army ,,& ,,morse4 ,,morse4 ,,navy4 #a -- -- -- -- -- -- #aaaa #b -- -- -- -- #bbbb #c -- -- -- #aaab #d -- -- #bbba #e -- -- -- #aabb #f -- #bbaa #g -- -- -- -- #abbb #h -- -- -- -- #baaa #i -- -- -- -- -- -- #abba #j ------ -- -- -- -- -- #baab ,punctuation-- 4 ,p]iod -- -- 3 ,colon ,ko -- -- -- 2 ,semicolon ,si -- -- -- 1 ,comma -- -- -- -- --- 8 ,int]rogation -- -- -- -- 6 ,exclamation -- -- -- -- -- -- -- ,fraction l9e - - ,hyph5 ,hx -- -- ' ,apo/rophe -- -- -- -- ,p\nd ,/]l+ -- -- 77 ,p>5!sis ,pn -- -- -- -- ,quotation m>ks ,qn -- -- -- -- ,p>agraph -- -- -- -- ,brackets ,bn ,doll> m>k ,sx ,da% ,dx ,und]l9e ,ux ,! foll[+ abbreviations1 conv5tional signals1 & code calls are au?oriz$ 9 visual signal+3 ,,abbreviations4 a aft]4 b be=e4 c c4 h h4 n n4 r are4 t !4 u y4 ur y\r4 w ^w4 wi )4 y yes4 ,,code ,,calls4 ,int]national ,code use ,,icu 7,navy7 telegraph diction>y use ,,tdu 7,navy7 geographical li/ use ,,glu 7,navy7 g5]al signal use ,,gsu ,navy li/ use ,,nlu ,vessel's numb]s use ,,vnu ,ciph] ,a usea ,,cau ,ciph] ,b usea ,,cbu ,ciph] ,c usea ,,ccu ,,footnote3 a ,^! calls are = preconc]t$ use 9 or ) ! navy4 ,al?\gh ! use ( b "o alphabet is au?oriz$ 9 visual signal+ 9 ! ,u4 ,s4 ,army1 em]g5cies may arise :]e x may be imp]ative to use ei!r ! ,army & ,navy1 ! ,cont95tal ,morse1 or ! ,am]ican ,morse alphabet4 ,in/ructions = ! use ( ei!r alphabet "u su* conditions are giv54 ,,execution ,,( ,,signal ,,alphabets4 ,,! ,,army ,,& ,,navy ,,alphabet4 ,,signal+ ,,) ,,flag ,,or ,,tor*1 ,,h& ,,lant]n1 ,,beam ,,( ,,se>*light1 ,,& ,,heliograph4 ,!re is "o position & ?ree motions4 ,! position is ) ! flag or o!r appliance held v]tically1 ! signalman fac+ directly t[>d ! /ation ) :i* x is desir$ to communicate1 8 body erect & feet suffici5tly sep>at$ to insure /able equilibrium4 ,! fir/ motion 7"o or #a7 is to ! "r ( ! s5d]1 & w embrace an arc ( #ij1 />t+ ) ! v]tical & return+ to x1 & w be made 9 a plane at "r angles to ! l9e connect+ ! two /ations4 ,! second motion 7two or #b7 is a simil> motion to ! left ( ! s5d]4 ,! ?ird motion 7front1 ?ree1 or #c7 is d[nw>d directly 9 front ( ! s5d] & in/antly return$ upw>d to ! fir/ position4 ,! beam ( se>*light w be ord9>ily us$ exactly z ! flag1 ! fir/ position be+ a v]tical "o4 ,to use ! tor* or h& lant]n1 a footlight mu/ be us$ z a po9t ( ref]5ce to ! motion4 ,! lant]n is m conv5i5tly swung out upw>d to ! "r ( ! footlight = #a1 to ! left = #b1 & rais$ v]tically = #c4 ,9 us+ ! heliograph1 ! fir/ position is to turn a /eady fla% on ! receiv+ /ation4 ,! signals are made by %ort & long fla%es4 ,use %ort fla%es = #a1 two %ort fla%es 9 quick succession = #b1 & a long1 /eady fla% = #c4 ,! elem5ts = a lett] %\ld be slightly long] ?an 9 s\nd signals4 ,ea* ^w1 abbreviation1 or conv5tional signal is foll[$ by #c4 ,! full address ( a message is consid]$ z "o s5t5ce & w be foll[$ by ! signal #cc4 ,! signal to indicate t ciph] foll[s & ciph] ends is ) ! flag & tor* ,,xc#c1 & ) o!r me?ods1 except ! ,int]national ,code1 by ,,xc4 ,x w always prec$e & foll[ a ciph] message or su* "p ( a pla9 text message z is enciph]$4 ,! foll[+ conv5tional signals are au?oriz$ 9 ! use ( ! army & navy alphabet3 ,end ( a ^w #c ,end ( a s5t5ce #cc ,end ( a message #ccc ,num]als foll[ 7or7 num]als end xx#c ,signature foll[s sig4 #c ,error #ab #ab #c ,ackn[l$gm5t 7or7 ,i und]/& #bb #bb #c ,cease signal+ #bb #bb #bb #ccc ,ciph] foll[s 7or7 ciph] ends #babb #aba #c ,wait a mom5t #aaaa #c ,repeat aft] 7^w7 #aba #aba #c #bb #c 7^w7 ,repeat la/ ^w #aba #aba #cc ,repeat la/ message #aba #aba #aba #ccc ,move a little to ! "r #baa #baa #c ,move a little to ! left #bba #bba #c ,signal fa/] #bbab #c ,,! ,,morse ,,alphabets4 ,,to ,,signal ,,) ,,! ,,flag1 ,,tor*1 ,,h& ,,lant]n1 ,,or ,,beam ,,( ,,se>*light4 ,! dot is made by a motion to ! "r ( ! s5d] embrac+ an arc ( #ij1 />t+ f ! v]tical & return+ to x1 9 a plane at "r angles to ! l9e connect+ ! two /ations4 ,! da% is made by a simil> motion to ! left4 ,! space :i* occurs only betwe5 dots is made by prolong+ ! signal = ! la/ dot = an int]val ( "t equal to ! "t ( an additional dot1 ! /aff ( ! flag1 ! beam ( ! se>*light1 etc41 be+ ma9ta9$ 9 a horizontal position = ! "t specifi$4 ,! signal s made w\ld !re=e repres5t a dot & space4 ,! lett] ,c is accord+ly made ?us3 ,"r1 "r prolong$1 "r4 ,! long da% 7,l7 is di/+ui%$ f ! %ort da% 7t7 by prolong+ ! signal to ! left = a p]iod ( "t equal to "o dot4 ,! long da% repres5t+ naught is simil>ly made by prolong+ ! signal to ! left = a p]iod ( "t equal to two dots4 ,! front signal is made by l[]+ ! flag f ! v]tical position to ! front & imm$iately return+ x to ! v]tical position4 ,a slight pause is made betwe5 ea* signal4 ,! foll[+ conv5tional signals are au?oriz$1 us+ ! ,morse alphabets3 ,end ( ^w "o front4 ,end ( s5t5ce two fronts4 ,end ( message ?ree fronts4 ,,to ,,signal ,,) ,,! ,,heliograph ,,or ,,fla% ,,lant]n4 ,! dot is made by press+ d[n ! key ( ! %utt] & imm$iately releas+ ! same4 ,! %ort da% is made by press+ d[n ! key & hold+ x d[n = a p]iod equal to two dots4 ,! long da% 7,l7 is made by hold+ d[n ! key = a p]iod equal to ?ree dots :ile ! long] da% 7naught7 requires ! key to be held d[n = a p]iod equal to f\r dots4 ,! space is made on ! heliograph z 9 ord9>y telegraphy by ! abs5ce ( any signals = a p]iod equal to ! "t ( "o dot4 ,on ! heliograph ! lett] ,c is made z foll[s3 ,%ort fla%1 %ort fla%1 int]val1 %ort fla%4 ,illu/ration3 ,fig4 #ad4 ,illu/ration3 ,fig4 #ae4 ,:5 ! call ( a /ation is ackn[l$g$1 bo? /ations w adju/ ea* on ! fla% ( ! o!r4 ,:5 adju/m5ts are satisfactory1 ! /ation call$ w ackn[l$ge & cut (f its fla%1 & ! call+ /ation w proce$ ) its message4 ,,int]national ,,code ,,( ,,signals4 ,description4--,by means ( ! ,int]national ,code ( ,signals p ( diff]5t nationalities may communicate ) ea* o!r1 al?\gh nei!r p>ty has k ( any language save 8 own native language4 ,! code is1 z its "n indicates1 int]national1 & e seago+ vessel ( e nation is equipp$ ) its flags4 ,! ,code ( ,signals contemplates ! use ( #bf flags 7figs4 #ad & #ae72 "o = ea* lett] ( ! alphabet & a code p5nant4 ,complete in/ructions relative to ! use ( ?is code are conta9$ 9 a book issu$ by ! ,hydrographic ,(fice1 ,navy ,dep>tm5t1 & kn[n z ! ,! ,int]national ,code ( ,signals4 ,9 us+ ?is sy/em ! signals are display$ by hoi/+ comb9ations ( two1 ?ree1 or f\r flags4 ,all possible comb9ations repres5t words1 expressions1 or phrases1 :i* may be f\nd 9 ! ,int]national ,code ( ,signals1 ref]r$ to above4 ,two-arm semaphore4--,?is sy/em is frequ5tly us$ by ! ,unit$ ,/ates ,navy1 ! foll[+ in/ructions cov]+ ! use ( ! sy/em3 #a4 ,to communicate ) a /ation3 ,face ! /ation & wave ! flags ov] ! head to attract att5tion1 mak+ at frequ5t int]vals ! call lett] ( ! /ation4 ,:5 ! /ation call$ is ready to receive ! message1 x answ]s by display+ its own call lett] until ! s5d] makes ! alphabetical or num]al1 z ! case may be4 ,!n proce$ ) ! message4 ,at ! end ( ea* ^w br+ ! flags across ! l[] "p ( ! body4 #b4 ,to call a %ip3 ,hoi/ ,int]national ,code lett] ,j & make code lett] ( %ip2 !n proce$ z 9 article #a4 #c4 ,to make a g5]al semaphore signal3 ,hoi/ cornet2 all %ips answ] by answ]+ p5nant2 !n make signal4 #d4 ,at ! end ( ! message ext5d ! arms horizontally & wave ! flags until ! receiv] answ]s 9 ! same mann]1 %[+ t ! message is und]/ood4 ,%\ld ! receiv] miss a ^w1 he signifies ! fact by wav+ ! flag ov] 8 head4 ,! s5d] w !n cease signal+ & wave 8 flags simil>ly to %[ t he und]/&s4 ,! receiv] !n makes repeat la/ ^w1 or :atev] he wi%es to say4 ,%\ld ! s5d] make a mi/ake1 he w make ! error signal until answ]$ by ! receiv] ) ! same signal4 ,he !n proce$s ) ! message4 ,,! ,,ardois ,,sy/em4 ,9 us+ ?is sy/em 9 connection ) ! ,army & ,navy ,code1 ! r$ lamp indicates #a & ! :ite lamp #b4 ,f\r lamps are plac$ on a v]tical /aff & electrically illum9at$ to indicate ! num]als ( ! ,my] ,code1 :i* repres5ts ! lett]s ( ! alphabet4 ,= in/ance1 :ite-:ite1 or #bb1 repres5ts ! lett] ,a1 & :ite-r$-r$-:ite1 or #baab1 repres5ts ! lett] ,b1 etc4 ,9 ?is sy/em ! lights indicat+ ! lett]s ( ! alphabet are read f ! top d[nw>d4 ,:5 ! lamps are plac$ horizontally1 !y are read f ! s5d]'s "r to 8 left1 & consequ5tly f ! receiv]'s left to 8 "r4 ,:5 ! lett]s ( ! alphabet are to be us$ to indicate ! mean+ set opposite !m 9 ! foll[+ tabulation1 ! upp] light ( ! display is pulsat$4 ,?is is effect$ by means ( a special pulsat+ key4 ,special signification is n giv5 ,i & ,t1 !y be+ repres5t$ by a s+le lamp4 ---------------------------------------- ----------- ,/eady ,upp] light pulsat$4 display4 ---------------------------------------- ----------- ,a ,ciph] ,a use4 ,b #j 7naught74 ,c ,repeat 7foll[+ rule = conv5tional signals "u wigwag code74 ,d ,telegraphic diction>y use4 ,e ,error4 ,f #d4 ,g #f4 ,h ,compass signals use4 ,i ,j #e4 ,k ,negative4 ,l ,geographical li/ use4 ,m #i4 ,n ,ciph] ,b use4 ,o ,ciph] ,c use4 ,p ,affirmative4 ,q ,int]rogatory4 ,r ,int]national code use4 ,s ,g5]al signals use4 ,t ,u ,navy li/ use4 ,v #g4 ,w ,annull+4 ,x ,num]als4 ,y ,vessels' numb] use4 ,z #b4 ,lett]s #c4 ,code call #h4 ,int]val ,boat signals use4 ---------------------------------------- ----------- ,be=e num]als are made1 ! di/9ctive signal = num]als ,x is %[n & ! upp] light is pulsat$1 :i* s]ves /ill fur!r to di/+ui% !m f lett]s4 ,! resumption ( lett]s aft] us+ num]als w be indicat$ by ! upp] light be+ no long] pulsat$1 b ! display lett]s 7#c7 w be turn$ on z an additional indication4 ,! ackn[l$gm5t ( ! correct receipt ( a message w be indicat$ by ! lett] ,r4 ,if ! message has n be5 fully receiv$1 or if x is n und]/ood1 indication !re( w be made by signal+ ! lett] ,g4 ,! end ( a ^w is indicat$ by #bbab4 ,,co/on ,,signals4 ,lett]s ( ! army & navy alphabet may be repres5t$ at night by ,co/on lights1 port fires1 or o!r color$ pyrote*nical lights by display+ ! r$ = "o & ! :ite = two4 ,9 us+ ! ,morse alphabet ! r$ repres5ts ! dot & ! :ite ! da%4 ,co/on signals & o!r simil> lights are be/ suit$ = preconc]t$ signals4 ,,v',s ,,night ,,signals4 ,! navy signal book is us$1 to :i* ! foll[+ explanation ref]s3 ,! lett] ,r /&s = r$ & ! lett] ,g = gre51 & ea* lett] designates a sep>ate /> or c>tridge4 ,bracket$ />s are a pair ( diff]5t colors1 dis*>g$ toge!r f two pi/ols4 ,! sy/em is bas$ on ! ,army & ,navy ,code1 r$ repres5t+ #a & gre5 #b4 #a--,,rrrr4 #b--;,,gggg4 #c--,,rrrg4 #d--;,,gggr4 #e--,,rrgg4 #f--;,,ggrr4 #g--,,rggg4 #h--;,,grrr4 #i--,,rggr4 #aj--;,,grrrg4 ,affirmative1 or ,yes ,,rgrg ,negative1 or ,no ,,grgr ,num]al ,,grgg ,int]rogatory ,,rgrr ,annull+ ,,rrgr ,divisional po9t1 date1 designator1 or int]val ,,ggrg ,r ,telegraphic diction>y1 bracket$4 ,g ,r ,geographical li/1 foll[$ by a rocket4 ,g ,r ,boat signals1 rocket foll[$ by ,g ,r ,r ,navy li/ ,g ,g ,g5]al call1 rocket foll[$ by ,g4 ,message call1 ,g )\t ! rocket4 ,! squadron1 division1 section1 or %ip's call1 ! numb] ( squadron1 division1 section1 or %ip4 ,answ]+1 or ,i und]/& ,r ,repeat+1 or ,i d n und]/& ,g ,dang] or di/ress1 ,r repeat$ sev]al times 9 quick succession4 ,,rocket ,,signal+4 ,9 g5]al1 rockets & %ells are be/ us$ 9 display+ preconc]t$ signals4 ,sequ5ce rockets may also be us$ to display diff]5t color$ lights 9 sequ5ce to repres5t lett]s or num]als ( ! army & navy alphabet4 ,! me?od ( atta*+ ! sections 9 ! base ( ! sequ5ce rocket is describ$ 9 ,*apt] ,,iii4 ,9 us+ sequ5ce rockets 9 ?is mann]1 ! elem5t #a ( ! army & navy alphabet is repres5t$ by a r$ />1 :ile a :ite /> repres5ts ! elem5t #b4 ,to s5d ! lett] ,a a rocket %[+ two :ite />s is s5t up4 ,if ,b is to be s5t1 a rocket %[+ :ite-r$-r$-:ite is dis*>g$4 ,ea* /> burns = f\r to six seconds1 & !re is a slight int]val betwe5 ! visibility ( ea* />4 ,betwe5 two or m />s ( ! same color1 z ,a1 ,n1 ,d1 dummies1 :i* %[ no light & c>ry ! fire to ! next /> to be ignit$1 are employ$4 ,9 ! prep>ation ( codes = signals ) rockets or bombs !re %\ld always be arrang$ a prep>atory signal :i* means ,are y ready8 etc41 & an answ]+ signal1 :i* means ,repeat y\r la/ signal1 etc41 a signal annul1 :i* means ,disreg>d la/ signal1 & a signal to signify ! correct receipt ( ! complete message1 or ,signal se5 & und]/ood4 ,illu/ration3 ,,two-,,arm ,,semaphore ,,alphabet1 ,u4 ,s4 ,,navy4 ,illu/ration ,illu/ration ,,conv5tional ,,signals4 ,end ( ^w see in/ructions4 ,end ( message see in/ructions4 ,error see in/ructions4 ,repeat la/ ^w ,c1 'end ( ^w'1 once4 ,repeat la/ message ,c1 'end ( ^w'1 #c times4 ,use pap] & p5cil ,p1 'end ( ^w'1 twice4 ,,abbreviations4 ,a end ( ^w aft] ,b be=e ,c c ,h h ,n n ,r are ,t ! ,u y ,,ur y\r ,w ^w ,,wi ) ,y yes ,,pg p]mission grant$ ,,ng p]mission n grant$ ,,xx num]als foll[ ,illu/ration3 ,,summ>y ,,( ,,signals1 ,,army ,,& ,,navy ,,alphabet4 ,,*apt] ,,iv4 ,,! ,,field ,,message4 ,def9ition4--,! t]m field message is appli$ to all messages s5t ov] field l9es ( in=mation4 ,all field messages = transmission ov] field l9es ( in=mation by electrical or visual means %\ld be pla9ly writt5 by ! s5d] on ! blank =ms 9 ! ,unit$ ,/ates ,army ,field ,message ,book4 ,! practice ( v]bally deliv]+ telegrams to enli/$ m5 = transmission %\ld inv>iably be disc\rag$4 ,9 fram+ telegrams1 all words n important to ! s5se w be omitt$4 ,! la/ "n ( ! (fic] address$1 or 8 title1 & ! la/ "n ( ! s5d] are g5]ally suffici5t4 7,p>agraph #aaih1 ,army ,regulations47 ,! blank =m4--,! ,unit$ ,/ates ,army ,field ,message ,book issu$ by ! ,signal ,corps is #d-e_/h in*es wide by #f in*es long1 & conta9s #dj message blanks ) duplicate tissue %eets & two %eets ( c>bon pap]4 ,! message is writt5 on ! yell[ %eet1 :i* c be torn out = deliv]y4 ,! c>bon %eet is atta*$ to ! book1 & contr>y to ! cu/om 9 mo/ c>bon duplicat+ books1 is plac$ "u ! tissue %eet :5 a message is be+ writt54 ,:5 n be+ us$1 ! c>bon %eet %\ld inv>iably be kept 9 ! back ( ! book4 ,:5 ! upp] c>bon %eet has become worn out1 x %\ld be torn out & ! second c>bon %eet us$ in/ead4 ,! blank =m is %[n 9 figure #af4 ,! back ( ! blank is rul$ 9 squ>es & provid$ ) scales = use 9 mak+ sket*es4 ,illu/ration3 ---------------------------------------- ------------------------------- ,no4 ,s5t by ,"t ,rec'd ,u4 ,s4 ,,army ,,field ,,message4 #a ,k ,mo #a4ae by ,"t ,*eck ,a4 ,m4 ,^! spaces = ,signal ,op]ators only ---------------------------------------- ----------------------------------- ,communicat$ by ,"n ( s5d+ deta*m5t ,,buzz]1 ,,phone1 ,,telegraph1 ,f,headqu>t]s #a/ ,corps1 ,,wireless1 ,,lant]n1 ,,helio1 ,,flag1 ,,cycli/1 ,,foot ,,mess5g]1 ,location ( s5d+ deta*m5t ,,m\nt$ ,,mess5g]4 ,at,taylors ,s*ool ,h\se1 ,kansas 7,und]score means us$7 ,date,may #a1 #aiji;,h\r#ab4de ,p4 ,m4,no4 ------------------------------- ,to ,signals ,platte ,city1 ,mo4 ,reque/ t5 miles buzz] wire be s5t "h quick ,jones ,receiv$ ,,fig4 #af4 ,writ+ ! message4--,9 writ+ ! message ! "n ( ! s5d+ deta*m5t %\ld appe> aft] ! head+ f on ! upp] l9e1 z f ,headqu>t]s #a/ ,brigade1 :ile ! location ( ! s5d] %\ld appe> on ! second l9e aft] ! head+ at4 ,! head+ h\r on ! ?ird l9e %\ld %[ ! h\r ! message 0 writt5 & n ! h\r ! message 0 transmitt$4 ,! head+ receiv$ at ! bottom ( ! page is fill$ 9 by ! addressee & %[s ! "t ( ! receipt ( ! message by him4 ,,in/ructions ,,to ,,op]ators4 ,use ( message blank4--,! field message blank w be us$ = field messages bo? s5t & receiv$4 ,duties ( s5d+ op]ators4--,! s5d+ op]ator w ent] ! "t :5 ! message is h&$ him = transmission 9 ! left-h& corn] at ! bottom ( ! blank opposite ! ^w ,receiv$4 ,he w ent] 9 ! prop] places1 at ! head ( ! blank1 ! numb] ( ! message1 ! call lett] ( 8 /ation1 ) 8 p]sonal signal1 ! *eck 7numb] ( words or gr\ps ( ciph] conta9$ 9 message1 c\nt+ address & signature71 &1 aft] ,,ok has be5 receiv$1 he w ent] ! "t ! message 0 s5t1 & ! call lett] ( ! receiv+ /ation1 ) ! p]sonal signal ( ! receiv+ op]ator4 ,ord] ( transmission4--,to transmit a message1 ! op]ator w s5d3 7#a7 ,! numb] ( message & call lett] ( 8 /ation2 7#b7 8 p]sonal signal2 7#c7 ! *eck2 7#d7 fm foll[$ by "n ( s5d+ deta*m5t2 7#e7 at foll[$ by location ( s5d+ deta*m5t & date2 7#f7 ,ho foll[$ by h\r 7a4 m4 or p4 m47 message 0 writt52 7#g7 address 9 full2 7#h7 p]iod1 7 -- -- 72 7#i7 body ( message2 7#aj7 sig 7signature foll[s72 7#aa7 signature4 ,duties ( receiv+ op]ators4--,! receiv+ op]ator w add to ! message receiv$1 ! mon?1 date1 & ye>1 & omit ! sig1 fm1 & at1 &1 aft] satisfy+ himself t ! *eck & numb] ( words correspond w give ,,ok foll[$ by ! call lett] ( 8 /ation & 8 own p]sonal signal4 ,he w !n ent] 9 ! prop] places1 at ! head ( ! blank1 ! call lett] ( 8 own /ation1 ) 8 p]sonal signal & ! "t ! message 0 receiv$4 ,communications confid5tial4--,communications transmitt$ by telegraph or signals are always confid5tial & w only be reveal$ to ^? (ficially entitl$ to receive !m4 ,*eck+ ! message4--,9 prep>+ ! *eck ( ! message1 all words & figures writt5 9 ! address1 body ( ! message1 & ! signature w be c\nt$4 ,9 c\nt+ ! *eck ( a message1 all words1 :e!r 9 pla9 ,engli%1 code1 or ciph]1 pron\nceable or unpron\nceable1 or initial lett]s1 w be c\nt$ ea* z "o ^w4 ,! abbreviations = ! names ( places1 cities1 t[ns1 villages1 ,/ates1 ,t]ritories1 & ,prov9ces1 w be c\nt$ z if writt5 9 full4 ,9 ! names ( t[ns1 c\nties1 c\ntries1 or ,/ates1 all ( ! words w be c\nt$4 ,abbreviations ( weights & measures 9 common use1 & c>d9al po9ts ( ! compass1 w be c\nt$ ea* z "o ^w4 ,to prev5t liability to error1 numb]s & am\nts %\ld be writt5 9 words1 & :5 n s writt51 ! receiv+ op]ator w reque/ t x be done4 ,if ! writ] decl9es to write ! am\nts 9 words1 ! message w be accept$ z writt51 & ea* figure w be c\nt$ z "o ^w4 ,figures1 decimal po9ts1 & b>s ( division1 & lett]s w be c\nt$ ea* sep>ately z "o ^w4 ,9 ord9al numb]s1 ! affixes1 /1 d1 nd1 rd1 & ?1 w ea* be c\nt$ z "o ^w4 ,9 transmitt+ ! telegram %[n 9 figure #af1 ! foll[+ w\ld be s5t by ! op]ator3 ,no #a ,k ,mo ,,ck #ad ,,ob fm ,headqu>t]s #a/ ,corps at ,taylor's ,s*ool ,h\se ,kan #a ho #abde ,,pm to ,signals ,platte ,city ,mo4 ,reque/ t5 miles buzz] wire be s5t "h quick sig ,jones ,,*apt] ,v4 ,,! ,,signal ,,/ation4 ,,location ,,( ,,/ations4 ,9 field op]ations tactical consid]ations w usually prescribe )9 c]ta9 limits ! numb] & g5]al location ( signal /ations4 ,! g5]al directions = deploym5t be+ giv51 ! signalman w be call$ ^u to demon/rate 8 skill 9 ! selection ( p>ticul> locations mo/ conducive to ! effici5t s]vice ( in=mation4 ,illu/ration3 ,,fig4 #ag4--;,field signal /ation4 ,g5]al consid]ations4--,consid]+ all ?+s1 ! be/ location = a signal /ation is "o :i* af=ds maximum visibility & at ! same "t m9imum exposure to ho/ile obs]vation4 ,^! conditions1 app>5tly p>adoxical1 c be m or less reconcil$ by ! ex]cise ( +5uity on ! "p ( ! signali/4 ,a good !oretical k ( ! special requisites ( signal sites1 toge!r ) ! ability to apply x to ! conditions aris+ 9 any giv5 case1 w result 9 secur+ ! be/ obta9able locations4 ,! fir/ ess5tial ( ! signal /ation is visibility1 ! second be+ t ( concealm5t f ho/ile obs]vation4 ,9 acquir+ a mean betwe5 conflict+ requirem5ts1 ! foll[+ special consid]ations 9 ! selection ( /ations %\ld be consid]$4 ,backgr\nds4--,backgr\nds are important factors 9 ! selection ( signal+ sites4 ,sky backgr\nds are desirable z af=d+ /rong contra/ & are !re=e conducive to cel]ity 9 ! transmission ( signals4 ,!y are r>e & c only be secur$ :5 /ations are locat$ on ! exact cre/ ( ridges1 on m\nta9 peaks1 or on l&s :i* b\nd ! horizon ( view f ! o!r /ations4 ,/ations ) sky backgr\nds1 :ile af=d+ ! be/ facilities = transmission1 are little adapt$ to ! requirem5t ( secrecy4 ,d>k backgr\nds are f> m common & m easily obta9able ?an sky exposures4 ,!y af=d ! maximum means ( concealm5t f ho/ile obs]vation1 b mat]ially r$uce ! range1 spe$1 & accuracy ( signal transmission4 ,mix$ or brok5 backgr\nds are ^? :i* display v>i$ colors beh9d ! signals4 ,backgr\nds ( ?is description d n accord ) ei!r ( ! ess5tial requirem5ts ( ! signal /ation & %\ld be avoid$ :5ev] possible4 ,9 g5]al1 sky backgr\nds %\ld always be select$ = signal /ations :5 conditions are su* t ! requirem5t ( secrecy c be disp5s$ )2 if1 on ! o!r h&1 !re is reason to fe> t ! signals may be int]cept$ by ! enemy1 d>k backgr\nds %\ld inv>iably be *os51 ev5 ?\gh ! disadvantages !y impose1 r5d] !m less desirable visually4 ,azimu? ( /ations4--,! azimu? ( signal /ations %\ld1 if possible1 be su* t ! visual l9es ( in=mation %\ld int]sect ! v]tical plane ?r\gh ! app>5t c\rse ( ! sun1 at a consid]able angle4 ,/ations locat$ s z to be unavoidably view$ f ^! directions dur+ portions ( ! day are v liable to appe> envelop$ 9 a haze1 & telescopes1 if turn$ ^u !m1 are fill$ ) dazzl+ light4 ,if ! location ( /ations on or close to ! sun l9e is unavoidable1 sites af=d+ sky exposures %\ld be *os54 ,exposures ( ?is k9d obviate to a great ext5t ! difficulty ( sun haze & %\ld be secur$ :5 ?is difficulty is enc\nt]$ & x is impracticable to *ange ! azimu? ( ! /ation4 ,altitude4--,! location ( signal /ations at high altitudes w t5d to obviate difficulties aris+ f smoke1 haze1 & du/4 ,! undulation ( ! atmosph]e noticeable on a hot summ]'s day is always less at a di/ance f ! e>?'s surface1 & x is (t5 practicable to read signals f a tree or h\setop :5 !y w\ld be un9telligible f ! gr\nd4 ,?is air undulation is less ov] spots well %ad$ ?an ^? expos$ to ! gl>e ( ! sun1 a fact t %\ld be borne 9 m9d 9 all telescopic exam9ations4 ,ano!r reason = locat+ /ations at high altitudes is because ! cool night air1 ! smoke & du/ ( ! day1 & heavy mi/s lie close to ! gr\nd1 fill+ ! depressions & l[l&s1 :ile ! high] po9ts rema9 9 view4 ,/ations on high gr\nd are !n equally well adapt$ to day & night signal+4 ,sites & selections ( ?is k9d ( t]ra9 w n only (t5 preclude ! necessity = *anges ( location1 b also w all[ ! cont9u\s work+ ( ! /ation :5 signals made f l[] positions w\ld be invisible4 ,9 foggy or murky wea!r peaks & m\nta9 tops are usually envelop$ 9 mi/1 & "u ^! conditions /ations %\ld be situat$ on l[] gr\nd4 ,det]m9ation ( backgr\nd color4--,! color ( ! backgr\nd ( a /ation is t color aga9/ :i* ! signals appe> to be display$ :5 view$ f ! di/ant /ation4 ,hav+ *os5 a po9t entirely 9 view ( ! /ation or /ations to be communicat$ )1 & hav+ fix$ ! exact position ( ! signal+ app>atus1 ! color ( ! backgr\nd %\ld be det]m9$ z c>efully z conditions ( t]ra9 w p]mit4 ,if ! elevation ( ! di/ant /ation is )\t d\bt great] ?an t ( ! home /ation x is safe to assume t ! color ( ! backgr\nd w be t ( ! objects directly ar\nd & beh9d x4 ,on ! o!r h&1 if ! di/ant /ation unque/ionably occupies ! l[] position1 a sky exposure w usually result4 ,9 locat+ /ations x is v difficult1 if n impossible1 especially at long ranges1 to det]m9e ! color ( ! backgr\nd z view$ f ! di/ant /ation :5 ! /ations are approximately on ! same level4 ,?is c only be done by proce$+ 9 front ( ! home /ation & tak+ su* a position t x c be view$ ) ! eye on ! l9e ( sight betwe5 ! /ations4 ,! telescope %\ld be e/abli%$ ov] ! initial po9t ( ! home /ations & direct$ on ! di/ant /ation4 ,! obs]v] = backgr\nd %\ld proce$ to a po9t :]e 8 head is 9 ! c5t] ( ! field ( ! telescope4 ,look+ back at ! home /ation f ?is po9t1 ! color ( ! objects ab\t & j beh9d ! initial po9t w be ! color ( ! backgr\nd4 ,! correct det]m9ation ( backgr\nd color f ! vic9ity ( home /ations is usually difficult & unsatisfactory1 & x is consid]$ ! be/ me?od to e/abli% communication ) ! di/ant /ation by simultane\sly us+ sev]al k9ds ( signal+ app>atus1 t k9d produc+ ! mo/ intelligible signals be+ reta9$ = cont9u$ use4 ,*oice ( app>atus4--,sunlight conditions p]mitt+1 ! heliograph w ord9>ily be us$ = day signal+ on acc\nt ( ! advantages ( ! great range & spe$ af=d$ by x4 ,:5 its use is prohibit$ by wea!r conditions1 ! flag w be sub/itut$ = x4 ,! :ite flag w be us$ aga9/ d>k & ! r$ aga9/ sky or brok5 backgr\nds4 ,! di/ant /ation is ! bett] judge z to :i* color flag is be/ suit$ to giv5 conditions & ! color indicat$ by x %\ld inv>iably be us$4 ,= night signal+1 ! acetyl5e lant]n is usually employ$4 ,long-range night signal+ %\ld be done ) ! se>*light if available4 ,! employm5t ( ! semaphore1 9 daytime1 & ! ,ardois sy/em1 at night1 w be conf9$ to m or less p]man5t /ations4 ,rockets1 %ells1 night fires1 etc41 are only employ$ = special or em]g5cy signals4 ,miscellane\s consid]ations4--,= v>i\s reasons /ations %\ld n be locat$ at or ne> camp gr\nds4 ,^! localities usually af=d mix$ backgr\nds1 & ! pres5ce ( du/ & smoke & ! int]f]5ce caus$ by mov+ bodies ( troops & tra9s w militate aga9/ ! effici5t transmission ( signals4 ,/ations locat$ 9 vic9ities ( ?is k9d are also subject to annoyance f noise & visits ( unau?oriz$ p]sons4 ,signal /ations %\ld be conv5i5t = mess5g] s]vice & h5ce z ne> commonly travel$ roads z ! physical cont\r ( ! c\ntry w p]mit4 ,locations = signal /ations %\ld be s select$ t ! visual l9es d n cross travel$ roads1 camps1 etc41 z du/ & smoke 9 ! daytime & lights at night are factors 9 det]m9+ ! visibility ( signals4 ,signal /ations c if necess>y be artificially conceal$ by erect+ scre5s con/ruct$ ( limbs ( trees1 etc41 ab\t ! flanks & re>4 ,%elt]$ positions %\ld be utiliz$ 9 w9dy wea!r4 ,int]visibility table4--,! foll[+ table %[s ! ext5t ( horizon = diff]5t heights above ! sea level--t is1 x %[s h[ f> "o c see an object :i* is itself at ! level ( ! sea3 --------------------------------------- ,di/ance ,height ( ! eye above sea 9 /atute level4 miles4 --------------------------------------- #aj feet #d #ae feet #e #bj feet #f #cj feet #g #dj feet #h #ej feet #i #fj feet #aj #gj feet #aa #he feet #ab #ajj feet #ac #aae feet #ad #acj feet #ae #aej feet #af #bjj feet #ah #bcj feet #bj #cjj feet #bc #cej feet #be #ejj feet #cj #gjj feet #ce #ijj feet #dj --------------------------------------- ,a =mula to det]m9e approximately ! limits ( visibility f a giv5 height is z foll[s3 ,! squ>e root ( ! height ( ! /ation 9 feet multipli$ by #a4bf equals ! di/ance 9 miles at :i* ! signal is visible4 ,h5ce1 an obs]v] ^: eye is #cj feet above ! sea c di/+ui% an object #g miles di/ant1 provid$ x is at ! sea level2 b if ! object is itself #ae feet above ! sea he c make x out #g #e #ab miles (f4 ,,f9d+ ,a ,,/ation4 ,to f9d a signalman ne> any kn[n /ation1 note ) ! unaid$ eye "s prom95t l&m>k ne> :i* ! look$-= p]son or object is suppos$ to be1 & direct ! telescope ^u ! place1 z sight is tak5 ov] a gun b>rel1 cov]+ ! object2 if ! eye is n[ plac$ at ! eyeglass ( ! telescope1 ! prom95t or direct+ l&m>k w be f\nd 9 ! field ( view4 ,x w be easy !n to scale ! c\ntry ne> ! m>k] until ! signalman is f\nd4 ,?is me?od is (t5 necess>y at night1 :5 only a po9t ( light is se5 f> (f ?r\gh ! d>kness1 & ! telescope mu/ be turn$ ^u x4 ,:5 ! compass be>+ ( ! object s\ght = is kn[n1 ! telescope may be align$ by a l9e drawn ) ! prop] compass be>+4 ,comm5c+ !n ) ! view at ! horizon1 ! telescope is sl[ly mov$ f side to side1 tak+ 9 fre% fields ( view ea* "t a little ne>] to ! obs]v]1 until ! :ole c\ntry %all h be5 obs]v$ f ! horizon to q ne> ! /ation4 ,:5 ! g5]al direction only ( ! object c be giv5 & x is s\ght =1 ! :ole l&scape 9 t direction to ! horizon %\ld be divid$ into sections by imag9>y l9es1 ! limits ( ^! sections be+ b\nd$ betwe5 visible l&m>ks ?r\gh :i* ! b\nd+ l9es are suppos$ to pass4 ,ea* section %\ld be scrut9iz$ little by little until ! glass has be5 pass$ ov] e spot4 ,su* se>* w seldom fail to be successful4 ,! magnetic be>+s ( all /ations ) :i* ano!r /ation has work$ %\ld be c>efully not$ & made matt] ( record 9 ! (fice directly conc]n$1 s t advantage\s use may be made ( ?is data4 ,9 addition1 guide l9es may be e/abli%$ by driv+ two /akes firmly into ! gr\nd & close to ea* o!r4 ,a prolongation ( a l9e ?r\gh ! c5t] ( "o po/ & m>k$ on ! adjac5t "o w /rike ! di/ant /ation4 ,"u ea* l9e %\ld be writt5 ! "n ( ! /ation :i* x m>ks4 ,signal]s ^u p]man5t or semip]man5t /ations w exam9e1 f "t to "t1 e prom95t po9t )9 signal di/ance1 to see if communication is attempt$ !refrom4 ,attempts to attract ! att5tion ( a kn[n /ation1 9 ord] to be successful1 mu/ be p]si/5t4 ,!y %\ld nev] be ab&on$ until e device has be5 exhau/$1 & !y %\ld be r5ew$ & cont9u$ at diff]5t h\rs ( ! day & night4 ,x mu/ be rememb]$ t ef=ts :i* h fail$ because ! obs]v]'s att5tion has be5 drawn 9 ano!r direction may at any o!r mom5t be successful if ! obs]v+ glass *ances to be> on ! call+ signals4 ,dur+ ! :ole "t t signals are be+ made to attract att5tion ! call+ /ation mu/ wat* closely ) ! telescope ! /ation call$4 ,! wat* %\ld n be relax$ until communication is e/abli%$ or ! /ation ord]$ ab&on$4 ,illu/ration3 ,,fig4 #ah4--,signal ,corps heliograph /ation4 ,,op]ation ,,( ,,/ations4 ,p]sonnel4--,at signal /ations :]e cont9u$ op]ation is requir$ at lea/ a squad or set ( f\rs is requir$4 ,physical & m5tal exhau/ion always result f cont9u\s signal duty1 & z al]tness ( m9d & body is an indisp5sable factor 9 ! prev5tion ( errors1 two reliefs ( signalm5 %\ld be furni%$ ea* /ation :5ev] practicable4 ,! s5ior (fic] or enli/$ man is 9 *>ge ( ! /ation & is responsible = effici5cy & discipl9e4 ,he w require f ea* man a /rict & entire att5tion to 8 own imm$iate duties1 & p]mit no conv]sation t w di/ract ! m5 at "w4 ,he w be c>eful n to all[ p]sons to loit] ab\t ! /ation or )9 ! he>+ ( ! words call$ out to ! signal]4 ,! assignm5t ( m5 %\ld be su* t a cont9u\s wat* = signals is kept & ! responsibility = neglect to promptly answ] calls det]m9$4 ,( ! /ation m51 "o is ! s5d]1 ^: duty x is to transmit all signals to contigu\s /ations4 ,ano!r1 ! receiv]1 att5ds ! telescope & reads & calls (f ! signals display$ at ! di/ant /ation4 ,a ?ird man acts z record]1 alt]nately call+ (f ! outgo+ message to ! s5d] or transcrib+ ! incom+ message repeat$ by ! receiv]4 ,calls & p]sonal signals4--,ea* /ation w be assign$ a call consi/+ ( "o or two lett]s4 ,ea* & e op]ator w also h a p]sonal signal ( l "*4 ,/ation calls or p]sonal signals :5 once giv5 or assum$ w n be *ang$ except by ord] ( high] au?ority4 ,e /ation %\ld at all times h on h& a li/ ( all calls & p]sonal signals liable to be enc\nt]$ 9 /ation work+4 ,! g5]al call suit$ to attract ! att5tion ( any /ation ^: regul> call is unkn[n w always be a signal repres5t$ by ! lett] ,a 9 ! ,morse or ! lett] ,e ( ! ,army & ,navy ,code4 ,op5+ communication4--,to op5 communication ) any di/ant /ation ^: call is kn[n1 signal ! call repeat$ly1 occasionally sign+ ! call ( ! home /ation4 ,if ! regul> call ( ! /ation s\ght is unkn[n ! g5]al call above prescrib$ %\ld be us$4 ,z soon z ! call is obs]v$ ! call$ /ation w ackn[l$ge receipt by ii ii1 or ,i und]/&1 sign+ !reaft] its /ation call4 ,^! prelim9>ies complet$1 ! /ations are ready = work+4 ,x is sometimes difficult to secure ! att5tion ( /ations at unexpect$ h\rs4 ,! =ce may n be /rong en\gh = an un9t]rupt$ wat*4 ,to provide1 s f> z possible1 = ?is cont+5cy1 x may be conc]t$ t if communication is requir$ at unusual "t1 or is ( press+ importance1 c]ta9 flags %all be display$1 rockets dis*>g$1 smokes %[n1 or o!r att5tion-compell+ signals us$4 ,:5 a numb] ( /ations are 9 view f "o /ation & x is desir$ to s5d a message to all or m ?an "o /ation1 "s preconc]t$ signal1 z a rocket1 a r$ light1 or "s peculi> flag or tor* signal1 %\ld be designat$ z a signal = g5]al att5tion4 ,^u notic+ ?is signal all ! call$ /ations reply1 & !n obs]ve ! call+ /ation4 ,?is plan is useful :5 two or m /ations c1 at ! same "t1 read ! signals f ! "o /ation1 & ?us toge!r receive any in=mation to be transmitt$ f x4 ,:5 a signal /ation is to communicate ) two or m /ations1 a telescope %\ld be firmly fix$ be>+ on ea*1 :5 practicable1 & s f> ap>t t ^? communicat+ ) "o /ation w n di/urb ! o!r p>ty4 ,comm5c+ ! message4--,e message is inv>iably comm5c$ by ! signal ,hr or ,anr4 ,sometimes at ! comm5cem5t ( communication a preface w be s5t 9 ord] to give "s prep>atory in=mation to ! receiv+ /ation reg>d+ ! numb] or "* ( messages ab\t to be s5t4 ,= example1 ,hr #h1 means ,i h eight = y or ,hr ck #cjj means a ?ree hundr$ ^w message foll[s4 ,s5d+ & receiv+4--,be=e ! comm5cem5t ( a message1 c>e %\ld be tak5 t all ! lett]s & *>act]s !re( are entirely & correctly und]/ood by ! signalman ^: duty x is to call ! same to ! s5d+ op]ator4 ,! message is read (f by ! read]1 :o fir/ calls (f a ^w & !n spells x out lett] by lett]4 ,! read] %\ld obs]ve ! signals ( ! op]ator & invite 8 att5tion to any app>5t errors4 ,:5 ! la/ lett] ( a ^w is ann\nc$ ?is fact w be communicat$ to ! s5d+ op]ator4 ,at ! receiv+ /ation ! man at ! telescope w call (f ea* lett] z receiv$ & n wait until ! completion ( a ^w4 ,on rea*+ ! end ( a ^w ann\ncem5t ( ?is fact w be made to ! record]4 ,break+4--,if ! s5d+ op]ator discov]s t he has made an error :i* w probably r5d] ! s5se ( ! message un9telligible at ! receiv+ /ation1 he w make ! signal ,,bk & recomm5ce ! message1 beg9n+ at ! la/ ^w correctly s5t4 ,:5 ! receiv+ /ation fails = any reason to get correctly :at is be+ s5t1 ! s5d+ /ation is int]rupt$ by ! signal ,,ga1 foll[$ by ! la/ ^w correctly receiv$4 ,! message w !n be recomm5c$ by ! s5d+ /ation at ! po9t indicat$4 ,discont9uance ( transmission4--,:5 all ! messages on file at any /ation h be5 s5t ! signal ,,nm 9 ,morse or ,cease signal+ 9 ! army & navy sy/em1 accord+ to :i* code is au?oriz$1 w be ! conclud+ signal ( ! s5d+ /ation4 ,:5 a signal /ation is op]at$ only dur+ ! daytime1 ! signal ,,gn w be transmitt$ aft] all bus9ess fil$ up to ! h\r designat$ = clos+ has be5 dispat*$4 ,ackn[l$gm5t ( receipt4--,no message w be consid]$ s5t until receipt = ! same has be5 ackn[l$g$4 ,?is is effect$ by mak+ ei!r ! ,i und]/& ( ! army & navy or ! ,,ok ( "o ( ! ,morse sy/ems1 dep5d+ ^u ! "o au?oriz$4 ,9 e case ! receiv+ op]ator's signal is sign$ aft] ackn[l$gm5t4 ,:5 a numb] ( messages are cont9u\sly s5t1 "o ackn[l$gm5t = all w suffice & w be s und]/ood4 ,9 receiv+ messages no?+ %\ld be tak5 = grant$ & no?+ consid]$ z se5 until x has be5 positively & cle>ly 9 view4 ,/ation records4--,records kept at field signal /ations w be conf9$ to orig9al files ( messages s5t & c>bon copies ( messages receiv$4 ,ord9>ily ! only available /ation]y w be ! ,unit$ ,/ates ,army ,field ,message ,book4 ,/ation records w be inv>iably pres]v$ z "p ( ! /ation equipm5t until ord]s = _! disposition are giv5 by high] au?ority4 ,:5ev] a /ation is 9 imm95t dang] ( capture1 all records %\ld be de/roy$ 9 ! discretion & "u ! direction ( ! op]ator 9 *>ge4 ,=mation ( signals4--,make signals ) regul>ity2 d n s5d "o ^w rapidly1 ! next sl[ly2 adopt su* a rate ( spe$ z c be read by ! di/ant signal] )\t caus+ him to break frequ5tly4 ,make a di/9ct pause betwe5 lett]s4 ,x is "t ga9$ to d s2 x is a loss ( "t & an annoyance to run lett]s toge!r4 ,no?+ s di/+ui%es ! good f ! indiff]5t op]ator1 visual or telegraph1 z ?is4 ,:5 signals are be+ made ) a flag1 a fraction ( a second w be ample4 ,9 us+ ! lant]n or heliograph1 ! pause betwe5 lett]s %\ld be relative to ! "t ( display ( ! elem5ts1 long] ?an ) ! flag4 ,to prev5t any entangl+ ( ! flag ^u its /aff1 skillful h&l+1 acquir$ by practice1 is necess>y4 ,x is accompli%$ by mak+ a scoop ( ! flag aga9/ ! w9d1 ! movem5t describ+ an elongat$ figure #h1 ?us 4 ,! motions %\ld be made s z to display 9 ! lat]al waves ! :ole surface ( ! flag t[>d ! po9t ( obs]vation4 ,9 us+ ! heliograph1 if ! receiv] sees t ! s5d]'s mirror ne$s adju/m5t1 he w turn on a /eady fla% until answ]$ by a /eady fla%4 ,:5 ! adju/m5t is satisfactory1 ! receiv] w cut (f 8 fla% & ! s5d] w resume 8 message4 ,repeat+ ! message4--,x may happ5 t v important messages receiv$ by signals mu/ be v]ifi$ by repeat+ back f ! receiv+ /ation1 signal by signal1 ea* signal us$ by ! s5d+ /ation 9 convey+ ! message4 ,!re c be no error 9 signals ?us v]ifi$1 & ! correct transmission ( ! message is made c]ta94 ,= su* v]ification ea* signal mu/ be repeat$ by ! receiv+ /ation z soon z x is made at ! s5d+ /ation4 ,signal practice4--,full effici5cy ( ! signal] c be ma9ta9$ only ?r\gh con/ant practice1 & ^? 9 *>ge ( ,signal ,corps troops %\ld see t suffici5t practice be _h to insure t accuracy & rapidity 9 h&l+ messages :i* is s ess5tial 9 "t ( w>4 ,in/ruction %\ld comm5ce ) ! /udy ( ! pr9ciples ( signal+ & ! !ories ( _! g5]al use1 & ! pupil %\ld be well gr\nd$ 9 ?is /udy be=e practice is begun4 ,he %\ld s memorize ! alphabets to be us$ t no lett] comb9ation w require ?\ght to det]m9e its mean+4 ,daily inspections %\ld be made to insure t all signal+ in/rum5ts1 appliances1 & mat]ials are 9 read9ess = in/ant use4 ,defects 9 ! app>atus annoy ! s5d]2 to a great] ext5t !y annoy ! p]son to :om ! messages are imp]fectly s5t1 & delays result t may h s]i\s consequ5ces4 ,,*apt] ,,vi4 ,,codes ,,& ,,ciph]s4 ,a code is a li/ or collection ( arbitr>y words or gr\ps ( lett]s to ea* ( :i* "s ord9>y ^w1 prop] "n1 phrase1 or s5t5ce is assign$ = mean+4 ,ciph]s embrace all means :]eby writ+s may be transcrib$ into occult t]ms4 ,all ciph]s employ "s di/9ct me?od = transcription1 :i* me?od is t]m$ a key4 ,9 practice ! key is usually appli$ directly 9 enciph]+ & rev]s$ 9 deciph]+ messages4 ,,codes ,,9 ,,use4 ,! codes ( ! ,we/]n ,union & ,po/al ,telegraph companies are examples ( well-kn[n codes suit$ to g5]al comm]cial use4 ,besides ^!1 _m special codes h be5 =mulat$1 s z to embody te*nical expressions especially adapt$ to use 9 p>ticul> l9es ( indu/ry4 ,! ,w> ,dep>tm5t ,code is a milit>y code adapt$ to ! special ne$s ( ! milit>y e/abli%m5t 9 peace & w>4 ,,employm5t ,,( ,,codes4 ,codes are prim>ily int5d$ = economy1 b !y may also be readily employ$ to secure secrecy4 ,:5 us$ solely = economy1 ! cod$ message is said to be pla9 code2 t is1 ! ^w or phrases ( ! message are cod$ by direct ref]5ce to _! respective code equival5ts4 ,?us pla9 code is readily translatable to anyone 9 possession ( a code book4 ,:5 secrecy is desir$1 "s me?od ( enciph]+ or key is employ$ 9 su* a way t only p]sons 9 possession ( x c 9 conjunction ) ! code book deciph] x4 ,9 su* case ! message is said to be 9 ciph] code4 ,,ciph] ,,code4 ,9 all codes ea* expression & its equival5t 9 pla9 language is assign$ a numb]4 ,^! numb]s usually comm5ce at unity & increase consecutively to any desir$ figure4 ,messages may be enciph]$ by means ( a key numb] or s]ies ( numb]s4 ,an additive numb]1 say #ee additive1 requires t 9 enciph]+ a message1 ! fifty-fif? ^w num]ically great] ?an ! prop] code ^w %all be us$2 if #ee subtractive is us$1 ! fifty-fif? ^w num]ically small] ?an ! prop] code ^w is to be us$4 ,by agreem5t a s+le key numb] c be us$ alt]nately additive & subtractive1 t is1 fir/ additive1 second subtractive1 ?ird additive1 etc4 ,! key numb]s are us$ ov] & ov] until ! entire message is enciph]$4 ,! key numb] c sometimes be express$ by a s+le ^w1 z1 = in/ance1 ,grant1 ea* lett] hav+ a value ( t5s 9 accordance ) its position 9 ! alphabet2 t is1 ,g1 ! sev5? lett] equals #gj2 ,r equals #ahj2 ,a equals #aj2 ,n equals #adj2 & ,t equals #bjj4 ,or by preconc]t$ arrangem5t lett]s may repres5t units or hundr$s4 ,security f translation by p]sons n hav+ ! key numb] is great] :5 ! key numb]s are us$ alt]nately additive & subtractive4 ,if a ciph] key ^w is us$1 x %\ld be "o ( an odd numb] ( lett]s1 z1 = in/ance1 ,jones1 ! numb]s correspond+ to ! positions ( ! lett]s 9 ! alphabet4 ,! fir/ numb] %\ld be additive1 ! second subtractive1 etc4 ,by ?is means ! fir/ lett] ( ! key ^w is additive ! fir/ "t x is us$1 subtractive ! second1 additive ! ?ird1 & s on4 ,9 "s in/ances ! key numb]1 :5 add$ to or subtract$ f ! code numb]1 gives a result+ numb] exce$+ ! highe/ code numb] or less ?an unity4 ,9 cases ( ?is k9d x %\ld be rememb]$ 9 enciph]+ t unity foll[s ! highe/ code numb] 9 addition1 & t ! highe/ code numb] foll[s unity 9 subtraction4 ,9 deciph]+ a message ! process ( enciph]+ is rev]s$4 ,,! ,,w> ,,dep>tm5t ,,code4 ,z previ\sly /at$1 ! ,w> ,dep>tm5t ,code is ! te*nical milit>y code & conta9s expressions numb]$ consecutively f #a to #fb1jjj4 ,all ! code words are compos$ ( #f lett]s1 :i* are s arrang$ t ! v[els & consonants inv>iably alt]nate4 ,9 ! =mation ( code words ! foll[+ #ac lett]s only are us$1 viz1 ,a1 ,b1 ,d1 ,e1 ,f1 ,g1 ,i1 ,k1 ,m1 ,n1 ,s1 ,u1 & ,x4 ,! body ( ! code book is arrang$ z foll[s3 7a7 ,army li/1 conta9+ ! "n ( e commission$ (fic] 9 ! regul> e/abli%m5t4 7b7 ,milit>y organizations1 giv+ all batt]ies1 companies1 troops1 etc4 7c7 ,milit>y po/s & /ations1 cov]+ ,alaska1 ,hawaii1 ,philipp9e ,isl&s1 ,porto ,rico1 & ! ,unit$ ,/ates4 7d7 ,unit$ ,/ates naval /ations & vessels4 7e7 ,geographical names4 7f7 ,miscellane\s tables z foll[s3 ,num]als4 ,arrivals & dep>tures4 ,dates4 ,indorsem5ts4 ,lett] ackn[l$gm5ts4 ,requisitions4 ,telegram ackn[l$gm5ts4 ,mails1 %ipm5ts1 & transports4 ,blanks = future additions z !y may be ne$$4 ,ranks & grades ( (fic]s & m5 9 ! ,army4 ,wireless /ations ( ! ,army & ,navy4 7g7 ,alphabetical li/ ( code expressions arrang$ conv5i5tly = use4 ,:5 x is desir$ to transmit "s ^w or expression n to be f\nd 9 ! code & no suitable synonym c be discov]$ ! ^w or expression %\ld be s5t 9 pla9 language or spell$ out by ! equival5ts = lett]s & end+s to be f\nd on page #ehi4 ,complete in/ructions = ! use ( ! code ei!r z a code or ciph] are conta9$ 9 ! introductory pages ( ! book4 ,,ciph] ,,code ,,9 ,,field ,,"w4 ,! use ( ciph] code 9 enciph]+ field messages w usually be practicable only betwe5 ! sev]al headqu>t]s & o!r l>ge /ations suppli$ ) code books4 ,?is me?od1 too1 is prohibitive = urg5t messages :5 ! "t ( enciph]+ & deciph]+ is an important factor connect$ ) deliv]y4 ,,field ,,ciph]s4 ,description & use4--,field ciph]s include all sy/ems & ! app>atus connect$ !re) :i* are ord9>ily employ$ 9 enciph]+ & deciph]+ field messages4 ,field ciph]s are int5d$ = use :5 code books are n available1 & h5ce ! employm5t ( ciph] code is preclud$4 ,"s me?ods ( field ciph] employ simple =ms ( app>atus1 :ile o!rs require ! use ( no app>atus at all4 ,=ms ( field ciph]4--,!re are two g5]al classes ( field ciph]4 ,! fir/ class employs ! transposition or rev]sal ( ! lett]s or words ( a message accord+ to "s preconc]t$ rule z a means ( secrecy4 ,! r\te ciph] h]eaft] describ$ is an example ( ?is class4 ,! me?od us$ 9 ciph]s ( ! second class consi/s 9 ! sub/itution ( c]ta9 lett]s or symbols = ea* ( ! individual lett]s compos+ ! words ( ! message4 ,bo? classes ( ciph] c be r5d]$ m effici5t by a judici\s use ( inv]sions & by ! concealm5t ( t]m9ations4 ,inv]sions4--,by ! inv]sions ( ! :ole or c]ta9 p>ts ( messages1 accord+ to "s preconc]t$ arrangem5t1 ! complications ( ciph] c be greatly increas$4 ,if a message is to be inv]t$1 ei!r z a :ole or by clauses1 x %\ld be inv]t$ be=e ! ciph] lett]s are writt5 ov] x4 ,messages may be fur!r complicat$ by s5d+ ! lett]s ( ea* ^w backw>d 9 v>i\s o!r pre>rang$ comb9ations4 ,concealm5t ( t]m9ations4--,to evade ! discov]y ( ! key or keys employ$1 x is mo/ important t ! t]m9ation ( ! words ( a message %\ld be conceal$4 ,! be/ me?od to conceal ! beg9n+1 & at ! same "t ! t]m9ation ( words1 is to divide !m into arbitr>y gr\ps ( f\r or five lett]s ea*4 ,?is proc$ure w add immeasurably to ! /r5g? ( ! ciph] & %\ld 9 no way confuse "o 9 possession ( ! key4 ,= in/ance1 ! words suffici5t "t w\ld be divid$ suff icie ntti me1 & su* bl9d lett]s z may be agre$ ^u to fill ! la/ two spaces ( ! la/ gr\p4 ,all su* artifices z ?is w surely delay a translator n 9 possession ( ! key4 ,,ciph] ,,app>atus4 ,! ciph] disk4--,! ciph] disk is compos$ ( two disks ( c>dbo>d1 lea!r1 or o!r mat]ial jo9$ conc5trically1 ! upp] disk revolv+ ^u ! l[]4 ,! alphabet1 read+ f left to "r1 & su* o!r signals1 num]als1 or comb9ations ( lett]s1 z may be desir$1 are pr9t$ ar\nd ! circumf]5ce ( ! l[] disk4 ,on ! upp] disk are pr9t$ ! alphabet & su* o!r signals1 num]als1 or comb9ations ( lett]s z are pr9t$ on ! l[] disk4 ,on ! l[] disk !y are pr9t$ f left to "r1 :ile on ! upp] disk !y are pr9t$ f "r to left4 ,if x is desir$ to enciph] a message1 ! key lett] or ! fir/ lett] ( ! key ^w or words is set opposite ,a4 ,let u assume x to be ,j4 ,! ciph] lett]s to be writt5 are ^? opposite ! text lett] :5 ! lett] a on ! upp] disk is set opposite ,j on ! l[] disk4 ,= example1 ,s5d p[d] w\ld be writt5 rfwg uvngfs4 ,hav+ a ciph] disk z above describ$1 ?is m]e transposition ( lett]s w\ld delay b a %ort "t ! deciph]+ ( a message by "o n kn[+ ! key lett]1 z x w\ld be necess>y only to place1 9 turn1 opposite a ea* ( ! lett]s ( ! alphabet beg9n+ ) b & not+ ! lett]s opposite ! enciph]$ lett]s4 ,b ?is simple disk c be us$ ) a ciph] ^w1 or pref]ably1 ciph] words kn[n only to ! correspond5ts1 & x is entirely improbable t a message s enciph]$ c\ld be deciph]$ 9 "t to be ( any value to ! enemy4 ,us+ ! key words p]man5t body to enciph] ! message ,re5=cem5ts w rea* y at daylight1 we w\ld proce$ z foll[s3 ,write out ! message to be enciph]$ & above x write ! key ^w or key words1 lett] ov] lett]1 ?us3 ,,p]man5tbodyp]man5tbodyp]man5tb ,re5=cem5tswillrea*y\atdaylight yanzvznlppkqfxijb,bpwanruqpeplomccwhmi ,n[ br+ ! a ( ! upp] disk "u ! fir/ lett] ( ! key ^w on ! l[] disk1 9 ?is case ,p4 ,! fir/ lett] ( ! message to be enciph]$ is ,r4 ,y is f\nd to be ! lett] connect$ ) ,r & x is put d[n z ! fir/ ciph] lett]4 ,! lett] a is !n br\ght "u ,e1 :i* is ! second lett] ( ! key ^w4 ,e is to be enciph]$ & a is f\nd to be ! second ciph] lett]4 ,!n br+ a to ,r & ! ciph] lett] w repres5t e1 ! ?ird text lett] ( ! message4 ,proce$ 9 ?is mann] until ! la/ lett] ( ! ciph] words is us$1 &1 beg9n+ aga9 ) ! lett] ,p1 s cont9ue until all lett]s ( ! message h be5 enciph]$4 ,divid$ into gr\ps ( f\r lett]s1 x w be z foll[s3 yanz vznl ppkq fxij bpwa nruq pepl omcc :mi4 ,illu/ration3 ,,fig4 #ai4--;,ciph] disk4 ,to deciph] ! message1 rev]se ! proce$+s above describ$2 ?us ! lett] a on ! upp] disk is br\ght "u ! fir/ lett] ( ! key ^w ,p4 ,foll[+ ^! in/ructions1 we f9d ! fir/ ciph] lett] ( ! message2 a is !n br\ght to ! next lett] ( ! key ^w4 ,9 ?is case ,e is1 ( c\rse1 ! next lett] ( ! text4 ,r is ! next lett] 9 ! key & a is br\ght ov] x4 ,! ciph] lett] n gives u ! next text lett]1 :i* is e1 & s on until ! completion ( ! message4 ,if ! lett]s ( ! key ^w or phrase are exhau/$1 beg9 aga9 ) ! fir/ lett] & s cont9ue until ! entire message is deciph]$4 ,) a key ^w1 or1 pref]ably1 a key phrase ( ?ree or f\r words1 ! deciph]+ ( a message is extremely difficult4 ,9 a milit>y ciph] message1 x may be desir$ to transmit num]als1 ! spell+ out ( :i* w\ld require consid]able "t4 ,?is c be done by an arrangem5t ( ! ciph] disk s t ! num]als ( :i* w appe> 9 ! same ord] z & foll[ ! lett]s ( ! alphabet4 ,?us on ! l[] disk #a is plac$ opposite ,a2 #b opposite ,b2 #c opposite ,c2 #d opposite ,d2 #e1 #f1 #g1 #h1 #i1 & #j opposite ,e1 ,f1 ,g1 ,h1 ,i1 & ,j1 respectively4 ,on ! upp] disk ! above num]als also appe>1 beg9n+ num]al #a opposite ,a2 #b opposite ,b1 etc41 #j be+ opposite ,j4 ,! arbitr>y sign ,,xx w be us$ to indicate num]als foll[ & num]als end4 ,suppos+ !n we wi% to s5d ! foll[+ message3 ,s5d #f1jjj cavalry at once1 & t ! key ^w 0 ,wa%+ton4 ,foll[+ ! in/ructions h]et(ore giv5 = enciph]+1 we w\ld place ! words z foll[s3 ,,wa%+tonwa%+tonwa%i ,,s5dxx#fjjj,,xxcavalryatonce ,,ewfelqbkfezdqhnnycqndmffe ,9 place ( a disk means may be extemporiz$ by tak+ two /rips ( pap]1 on "o ( :i* ! alphabet1 num]als1 etc41 are twice writt5 9 succession4 ,on ! o!r1 ) equal spac+1 ! alphabet1 etc41 are writt5 once1 b 9 rev]se ord]4 ,by slid+ ^! /rips 9 juxtaposition ) ea* o!r !y w replace ! disk4 ,ciph] disks %\ld nev] be all[$ to fall into ! h&s ( ! enemy or ( anyone unau?oriz$ to h & use !m2 to insure ?is1 special in/ructions %\ld be issu$ = _! c>e & keep+4 ,,! ,,ma!matical ,,ciph]4 ,?is ciph] is a highly effici5t "o = ! purpose ( secrecy & at ! same "t requires no app>atus :atev] att5dant ^u its use4 ,! ciph] is con/ruct$ z foll[s3 ,commit to memory ! alphabet by numb]s1 viz1 ,a1 #a2 ,b1 #b2 etc4 ,take any key ^w1 phrase1 or s5t5ce desir$2 = example1 ,a discov]y4 ,suppose ! message to be enciph]$ is ,s5d me p[d] tonight4 ,! enciph]+ ( ! message us+ ! key giv5 above w be z foll[s3 ,to enciph]1 fir/ write out ! key1 lett] by lett]1 plac+ ! message lett] by lett] b5ea? x4 ,!n r$uce ! lett]s ( ! key & ! message to ! num]al alphabetical equival5ts4 ,add ! individual columns & subtract unity f ea*4 ,f any result ?us f\nd1 :i* exce$s ! numb] ( lett]s 9 ! alphabet1 ! numb] #bf mu/ be subtract$4 ,! f9al totals r$uc$ to lett]s by num]ical alphabetical equival5ts w !n give ! ciph]4 ,,adiscov]yadiscov] s5dmep[d]tonight :i* r$uc$ to num]ical equival5ts accord+ to alphabetical position ( lett]s becomes3 #a #d #i #ai #c #ae #bb #e #ah #be #a #d #i #ai #c #ae #bb #e #ah #ai #e #ad #d #ac #e #af #ae #bc #d #e #ah #bj #ae #ad #i #g #h #bj ,n[ add ! columns & subtract unity f ea*4 ,if any result s f\nd exce$s ! numb] ( lett]s 9 ! alphabet #bf mu/ be subtract$ f x4 ,9 ! example giv5 ! num]ical totals are z foll[s3 #bj #i #bc #bc #af #bj #ch #bj #da #bi #f #bb #bi #cd #ag #bd #bi #ac #ch #a #a #a #a #a #a #a #a #a #a #a #a #a #a #a #a #a #a #a ---------------------------------------- --------------- #ai #h #bb #bb #ae #ai #cg #ai #dj #bh #e #ba #bh #cc #af #bc #bh #ab #cg #bf #bf #bf #bf #bf #bf #bf ---------------------------------------- --------------- #ai #h #bb #bb #ae #ai #aa #ai #ad #b #e #ba #b #g #af #bc #b #ab #aa :i* connect$ to lett]s gives3 ,,%vvosksnbeubg[blk ! ciph] requir$4 ,translation ( ciph] is _h by rev]s+ ! processes describ$4 ,,! ,,r\te ,,ciph]4 ,?is is a ciph] 9 :i* ! words or a message are reta9$ un*ang$1 b are s dis>rang$ by preconc]t$ rules t ! s5se becomes un9telligible4 ,! message z receiv$ seems to be a numb] ( disconnect$ words & )\t mean+1 b by arrangem5t 9 prop] ord] 9 accordance ) c]ta9 rules c be easily read4 ,messages enciph]$ 9 ?is mann] may be translat$ by p]sons n 9 possession ( ! key1 & !re=e ! in=mation conta9$ !re9 %\ld only be ( su* a "* z to be ( little value to ! enemy unless act$ ^u imm$iately4 ,! usual me?od employ$ 9 arrang+ a message = ?is ciph] is to write ! words 9 v]tical columns4 ,! numb] ( words 9 ea* column %\ld always equal ! numb] ( columns1 be+ made s1 if necess>y1 by ! addition ( suffici5t bl9d words4 ,a preconc]t$ r\te is agre$ ^u1 z up to ! fir/ column1 d[n ! ?ird1 up ! second1 etc4 ,! message is !n transmitt$ )\t ref]5ce to ! columns1 b is deciph]$ at ! receiv+ /ation by column arrangem5t & p]usal along ! orig9al r\te4 ,= example1 to enciph] ! message ,move daylight4 ,enemy approa*+ f nor?4 ,prison]s say /r5g? "o hundr$ ?\s&4 ,meet him z plann$1 arrange z foll[s3 ,move /r5g? plann$ say daylight "o z prison]s enemy hundr$ him nor? approa*+ ?\s& meet f ,"h ! r\te is d[n ! fir/ column1 up ! f\r?1 d[n ! second1 & up ! ?ird4 ,,ciph] ,,detection4 ,g5]al in/ructions4--,9 deciph]+ a message 9 :i* ! same ciph] lett] or symbol is uni=mly us$ to repres5t ! same text lett]1 ! foll[+ data w be ( assi/ance4 ,! proportion ( occurr5ce ( lett]s ( ! alphabet 9 ,engli% words is z foll[s3 ,= e #b ( ! lett] ,q !re are #d ( ! lett] ,x1 #h ( ,k1 #af ( ,b1 #ac ( ,c1 #hj ( ,i1 ,n1 ,o1 & ,s2 #he ( ,a1 #ij ( ,t1 & #abj ( lett] ,e4 ,! comp\nds mo/ frequ5tly met ) are ,,ng ,,ee ,,ll ,,mm ,,tt ,,dd & ,,nn4 ,! ord] ( frequ5cy 9 :i* ! lett]s ( ! alphabet occur z initial lett]s 9 words is z foll[s3 ,s1 ,c1 ,p1 ,a1 ,d1 ,i1 ,f1 ,b1 ,l1 ,t4 ,employm5t ( ,ciph] ,disk4 ,if messages are enciph]$ by a m]e transposition ( ! lett]s ( ! alphabet1 ! ciph] disk c be us$ to quickly deciph] ! message1 z ! foll[+ example w %[3 ,assum+ t ,f is us$ to repres5t ,a1 ,g to repres5t ,b1 ,h to repres5t ,c1 ,i to repres5t ,d1 ,j to repres5t ,e1 etc41 9 regul> sequ5ce1 & t ! message to be enciph]$ is3 ,we are %ort ( rifle ammunition2 s5d #cj1jjj r\nds at once4 ,?is w\ld be enciph]$ if divid$ into gr\ps ( f\r lett]s z foll[s3 jbfo bnyr omra oxub fuls xmxr snbs cmjb smhm yrln fsco rlsc nfmr sdb4 ,place a ( ! upp] ciph] disk "u ,b ( ! l[] disk & notice :e!r ! ciph] lett]s jbfo--! fir/ gr\p--are intelligible4 ,!y give sawn1 cont9ue ?is = saw1 ! fir/ ?ree lett]s1 may be ! text ^w4 ,n[ ! next gr\p is ,b ,n ,y ,r & ^! give ,a ,o ,d ,k4 ,we "k t ,a does n repres5t ,b because ! fir/ #h ciph] lett]s give ! mean+less lett]s sawnaodk4 ,turn a to ,c & we h = ! fir/ gr\p ,t ,b ,x ,o1 :i* is )\t mean+4 ,turn+ a to ,d we get ,u ,c ,y ,p1 a mean+less jumble4 ,turn a to ,e & we get ,v ,d ,z ,q1 :i* is mean+less4 ,n[ turn a "u ,f & we f9d t ,,jbfo mean ,we>1 :i*1 s f> at lea/1 gives u a "p ( a ^w1 or ! ^w ,we & "p ( ano!r ^w4 ,we cont9ue to ! next gr\p ,b ,n ,y ,r1 :i* gives u e%o4 ,we n[ h ^! lett]s ,we>e%o1 :i* at a glance we read ,we are %o2 cont9u+ to ! next gr\p ,o ,m ,r ,a ! ciph] disk gives u rt(1 & we read ,we are %ort ( & "k we h f\nd ! key lett]1 & ! in=mation hidd5 9 ! ciph] is ours4 ,cont9ue deciph]+ ) a "u ,f until ! end ( ! message4 ,sometimes ! key lett] is *ang$ aft] two1 ?ree1 or f\r lett]s4 ,x is a matt] ( m9utes only to run ?r\gh ! alphabet & le>n ! mean+ ( a message s enciph]$4 ,,*apt] ,,vii4 ,,field ,,glasses ,,& ,,telescopes4 ,reflection--refraction--l5ses4 ,illu/ration3 ,,fig4 #bj4 ,:5 light falls on a transp>5t body1 "p is reflect$ & "p is refract$4 ,! angle :i* ! ray makes ) ! normal1 or p]p5dicul>1 to ! surface at ! po9t ( contact is kn[n z ! angle ( incid5ce1 & ! angles :i* ! reflect$ & refract$ rays make ) ! same normal are kn[n respectively z ! angle ( reflection & refraction4 ,! reflect$ ray makes ! same angle ) ! normal z ! incid5t ray1 :ile ! refract$ ray1 :5 pass+ f a r>] to a d5s] m$ium1 is b5t t[>d ! normal1 & vice v]sa2 ! d5s] ! m$ium into :i* ! ray passes ! great] is ! deviation4 ,?is law all[s u at once to und]/& ! action ( a l5s1 :i* may be def9$ z a transp>5t m$ium t f ! curvature ( its surface causes ! rays ( light trav]s+ x to ei!r conv]ge or div]ge4 ,! ord9>y l5ses h ei!r sph]ical surfaces or a comb9ation ( sph]ical & plane surfaces4 ,?is comb9ation w give rise to six classes 7fig4 #bj73 7a7 ,d\ble convex2 7b7 plano convex2 7c7 d\ble concave2 7d7 plano concave2 7e7 conv]g+1 & 7f7 div]g+ m5iscus4 ,^? l5ses :i* are ?ick] at ! c5t] ?an at ! edges are conv]g+ or conc5trat+ l5ses1 & ^? :i* are ?ick] at ! edges ?an ! c5t] are div]g+4 ,,focus--,,optical ,,c5t]4 ,! focus ( a l5s is ! po9t :]e ! refract$ rays or _! prolongation meet2 if ! rays !mselves int]sect aft] refraction ! focus is real1 & if _! prolongations meet ! focus is virtual4 ,! l9e pass+ ?r\gh ! c5t]s ( curvature ( ! two surfaces ( a l5s is call$ ! pr9cipal axis & conta9s a po9t kn[n z ! optical c5t]1 :i* has ! prop]ty by virtue ( :i*1 if a ray passes ?r\gh x1 ! ray w n be deviat$4 ,! optical c5t] c always be f\nd by draw+ two radii p>allel to ea* o!r1 "o f ea* c5t] ( ! curvature ( ! surface until ! radii int]sect _! respective surfaces1 !n draw a l9e jo9+ ^! two po9ts4 ,! int]section ( ?is la/ l9e ) ! pr9cipal axis w give ! optical c5t]4 ,,image--,,conjugate ,,foci4 ,let ,,ab be ! section ( a d\ble convex l5s & ,c & ,d 7fig4 #ba7 be ! c5t]s ( curvature ( ! two surfaces4 ,draw ! l9es ,,cd & ,,de f ,c & ,d p>allel to ea* o!r1 !n jo9 ,d & ,e by a /raight l9e4 ,! po9t ,o w be ! optical c5t] ( ! l5s4 ,let u take a po9t ,r1 on ! pr9cipal axis z a s\rce ( light2 ! ray ,,rd passes ?r\gh ! optical c5t] & is n deviat$4 ,! ray ,,rk on /rik+ w be refract$ 9 ! direction ,,kg t[>d ! p]p5dicul> to ! surface ,,kd 9 accordance ) ! law ( refraction1 z glass is d5s] ?an air4 ,on em]g+ at ,g x is refract$ away f ! p]p5dicul> to ! surface ,,cg1 s9ce x passes f a d5s] to a r>] m$ium1 & w int]sect ! ray ,,rd at ! po9t ,r4 ,9 a l way ! ray ,,rk w be f\nd to int]sect ! ray ,,rd at ! same po9t1 ,r1 :i* is ! focus = all rays com+ f ,r4 ,! po9t ,r is said to be ! image ( ! object ,r1 & :5 ! two po9ts are consid]$ toge!r !y are call$ conjugate foci4 ,if ! incid5t beam is compos$ ( p>allel homog5e\s light1 ! rays w all be br\ght to a focus at a po9t on ! pr9cipal axis1 call$ ! pr9cipal focus ( ! l5s1 & ! di/ance ( ?is po9t f ! optical c5t] is ! pr9cipal focal l5g?1 :i* is always a fix$ quantity = any giv5 l5s4 ,illu/ration3 ,,fig4 #ba4 ,,law ,,( ,,foci4 ,!re is a fix$ relation betwe5 ! pr9cipal focal l5g? ( a d\ble convex l5s & ! position ( ! image ( ! object :i* may be express$ z foll[s3 #a_/;i #a_/;f - #a_/o1 9 :i* i & o are ! di/ances ( ! image & object1 respectively1 f ! optical c5t] & f ! focal l5g?1 f :i* we see t = all positions ( ! object f an inf9ite di/ance away f ! l5s to d\ble ! pr9cipal focal di/ance1 ! image w be on ! o!r side1 betwe5 a di/ance equal to ! pr9cipal focal l5g? & d\ble ?is l5g?4 ,^! are ! limits ( ! image & object 9 ! ord9>y cases4 ,if we place ?is expression 9 ! foll[+ =m3 i (_/7o - f71 & suppose ! object to rema9 ! same di/ance f v>i\s l5ses1 x w be se5 t ! image w be clos] to ! l5s :i* has ! %ort] focal l5g?4 ,! pr9cipal focal di/ance1 or1 briefly1 ! focal l5g? ( ! l5s1 dep5ds on ! curvature ( ! surfaces1 & ! great] ! curvature ! %ort] ! focal l5g?4 ,,=mation ,,( ,,image4 ,illu/ration3 ,,fig4 #bb4 ,let u n[ see h[ an image is =m$ by a convex l5s1 & suppose t ,,cd is ! section ( a d\ble convex l5s 7fig4 #bb71 ,o ! optical c5t]1 & ,,ab an object at a great] di/ance f ! optical c5t] ?an d\ble ! focal l5g?4 ,rays w pass out 9 all directions f ! object & "s w fall on ! l5s4 ,a ray f ,a w pass ?r\gh ! optical c5t] & w n be deviat$2 o!rs w be incid5t at v>i\s po9ts1 = example1 ,e & ,g1 & if we apply ! law ( refraction we w f9d t ,,ae & ,,ag w int]sect ea* o!r & ,,ao at ! po9t ,a1 provid$ we d n consid] ! figure ( ! l5s1 =m+ "o po9t ( ! image ,a ,b2 simil>ly = rays f o!r po9ts ( ! object1 z1 = example1 ,b1 we c con/ruct ! focus ,b1 & ?us obta9 ! image ,a ,b1 :i* is inv]t$ & small] ?an ! object ,,ab4 ,! relative size ( ! image & object w be directly z ! conjugate foci1 & ^! c be f\nd at once f ! equation ( ! l5s4 ,,sph]ical ,,ab]ration4 ,if1 h[ev]1 we consid] ! =m ( ! l5s1 we w f9d t all ! rays em]g+ f "o po9t on ! object are n br\ght to ! same focus1 because ! rays incid5t on ! edges ( ! l5s are refract$ to a great] ext5t ?an ^? fall+ on ! c5t]1 & w be br\ght to a focus at a %ort] di/ance f ! l5s ?an ^? pass+ ?r\gh ! c5tral "p4 ,?is confusion or w&]+ ( ! foci f "o po9t is call$ sph]ical ab]ration1 or ab]ration ( =m1 & is due solely to ! geometrical =m ( ! l5s4 ,,*romatic ,,ab]ration4 ,9 :at has be5 said ab\t ! visual image we h suppos$ t ! light 0 mono*romatic1 or homog5e\s4 ,let u see :at w happ5 if ! light is poly*romatic1 say1 = example1 sunlight1 & let a beam ( sunlight be int]cept$ on a scre5 aft] pass+ ?r\gh a d\ble convex l5s4 ,x w be obs]v$1 z 9 figure #bc1 t ! violet rays are br\ght to a focus ne>e/ ! l5s1 & ! r$ f>!/ away1 & circles ( light w be se5 on ! scre52 ?is w&]+ ( ! color$ rays f a common focus is call$ *romatic ab]ration & dep5ds on ! disp]sive prop]ties ( ! mat]ial ( :i* ! l5s is made4 ,"h is a defect t c n be correct$ by a /op1 b z ! refractive & disp]sive prop]ties ( a sub/ance d n v>y toge!r1 x is possible to comb9e two sub/ances1 "o ) high refractive & l[ disp]sive prop]ties & ! o!r ) ! rev]se prop]ties4 ,if prop] curves are giv5 to !m !y w correct ea* o!r1 !reby produc+ co9cid5ce ( ! visible & *romatic foci4 ,su* a comb9ation gives an a*romatic l5s1 :i* is usually compos$ ( a d\ble convex ( cr[n glass cem5t$ to a div]g+ m5iscus ( fl9t glass1 z %[n 9 section 9 figure #bd4 ,?is comb9ation is n absolutely a*romatic1 b suffici5tly s = all g5]al purposes4 ,illu/ration3 ,,fig4 #bc4 ,illu/ration3 ,,fig4 #bd4 ,,telescopes4 ,! telescope is an optical in/rum5t bas$ on an object glass or reflector to =m a real image ( a real & di/ant object1 & ( an ocul> to magnify & view ! image4 ,telescopes are classifi$ z refract+ or reflect+ accord+ z ! object glass is a l5s or a reflector4 ,! object glass mu/ be ess5tially convex if ! telescope is a refractor1 & if a reflector1 ! object mirror mu/ be concave2 ! ocul> may be ei!r concave or convex4 ,!re are f\r types ( refractive telescopes us$ = milit>y purposes1 viz3 #a4 ,! a/ronomical4 #b4 ,! t]re/rial4 #c4 ,! galilean4 #d4 ,! prismatic4 ,figure #bf is a section ( an a/ronomical telescope4 ,! object glass 7,d7 is a comb9ation consi/+ ( a d\ble convex & a d\ble concave l5s cem5t$ toge!r ) ,canada balsam4 ,! d\ble concave l5s is add$ to correct = *romatic ab]ration4 ,! ocul> 7,e7 is a convex-concave l5s4 ,rays ( light f "s di/ant object are conv]g$ by ! objective 7,d7 & =m an inv]t$ image 7ab7 at ! focal plane 7,f74 ,! eye l5s 7,e7 receives ! div]g5t p5cils f a & b & b5d !m s t !y ent] ! eye z if com+ app>5tly f ! direction ( a b :]e ! app>5t image is se54 ,f ! eyepiece 7,e7 ! rays em]ge 9 a cone ( p5cils ( light small] ?an ! pupil ( ! eye1 :i* enables a telescope ( ?is type to h a l>ge field ( view4 ,! image1 h[ev]1 is inv]t$ & ! a/ronomical telescope 9 its orig9al =m is !re=e n suitable = milit>y purposes4 ,9 a modifi$ =m x is mu* us$1 z w be %[n 9 a lat] p>agraph4 ,illu/ration3 ,figure #bf ,figure #bg is a section ( a t]re/rial telescope mu* us$ = milit>y purposes4 ,glasses ( ?is type are q g5]ally kn[n z spyglasses4 ,z 9 ! case ( ! a/ronomical telescope1 ! fir/ inv]t$ image ba is =m$ at ! focal plane 7,f71 & ! fir/ eyeglass conv]ges ^! p5cils to ,l4 ,in/ead ( plac+ ! eye at ,l1 z 9 ! a/ronomical telescope1 ! p5cils are all[$ to cross & fall on a second eyeglass1 by :i* ! rays ( ea* p5cil are conv]g$ to a po9t 9 ! second erect image a b1 :i* image is view$ by means ( ! ?ird & la/ eyeglass4 ,illu/ration3 ,figure #bg ,t]re/rial telescopes h a comp>atively small field ( view4 ,! b>rels ( ?is telescope are necess>ily long on acc\nt ( ! additional l5ses4 ,,galilean ,,field ,,glasses ,,& ,,telescopes4 ,figure #bh is a section ( a ,galilean telescope :i* diff]s f ! a/ronomical telescope 9 hav+ a d\ble concave in/ead ( a d\ble convex1 eyepiece or ocul>4 ,9 ?is telescope ! rays f an object are conv]g$ by ! object glass 7,o7 & w\ld normally focus at ! focal plane 7,c7 & !re =m ! inv]t$ image ba 7 x n t ! d\ble concave eyeglass or ocul> 7,d7 is s locat$ 9 ! b>rel ( ! telescope z to int]cept ! p5cils be=e !y are focus$4 ,?is d\ble concave eyeglass div]ges ^! p5cils & =ms a magnifi$ erect image a b app>5tly at ,e4 ,due to ! div]g+ action ( ?is concave eye l5s1 ! cone ( p5cils ent]+ ! eye is l>g] ?an ! pupil ( ! eye1 & !re=e b a small "p ( ! field ga!r$ by ! object glass is utiliz$ by ! eye1 :i* causes telescopes ( ?is type to h a comp>atively small field ( view4 ,illu/ration3 ,figure #bh ,,porro ,,prism ,,field ,,glasses ,,& ,,telescopes4 ,9 #ahej a ,fr5* eng9e]1 ,porro1 discov]$ a comb9ation ( prisms :i*1 :5 ins]t$ betwe5 ! objective & ! eyepiece ( an a/ronomical telescope1 %[$ ! image erect or 9 its natural position1 :ile ! same telescope )\t ! prisms %[$ ! image inv]t$4 ,practical use ( ?is discov]y 0 n made = _m ye>s aft]4 ,^! prisms s]v$ a tw(old purpose1 viz1 %[+ ! image ( ! object look$ at 9 its natural position in/ead ( rev]s$1 & second1 ! %ort5+ ( ! telescope by twice turn+ ! ray ( light ^u itself4 ,ea* tube ( ! prism field glass conta9s two ( ^! d\ble-reflect+ prisms4 ,! ray ( light pass+ ?r\gh ! object glass ent]s ! fir/ prism 9 su* a mann] z to be twice totally reflect$1 ea* "t at an angle ( #ij1 ?us em]g+ p>allel to ! ent]+ ray1 b 9 ! opposite direction4 ,x is ?us caught by ! second prism & is simil>ly reflect$ & s5t on its orig9al direction )\t *ange except 9 "o v important po9t1 viz1 ! image ( ! object obs]v$1 :i*1 )\t ! int]v5tion ( ! prism1 w\ld be upside d[n1 is n[ erect1 & w be magnifi$ by ! simple a/ronomical eyepiece j z ! />s & planets are magnifi$ 9 l>ge telescopes4 ,! field ( view ( ! ,porro prism glass is consid]ably l>g] ?an t ( ! ord9>y field glass4 ,x decreases ab\t #ab p] c5t ) ea* magnify+ p[]1 a numb] #f-p[] glass giv+ a l9e> view ( #aah feet 9 a ?\s&1 :ile 9 a numb] #aj glass ! field is b #gj l9e> feet4 ,?is is expla9$ z foll[s3 ,! rays ( light em]g+ f ! ocul> ( ! ,galilean telescope are div]g5t & cov] an area mu* great] ?an ! size ( ! pupil ( ! eye4 ,z all rays fall+ outside ! pupil ( ! eye are lo/1 b a small field ( view c be se51 z 9 look+ ?r\gh an ord9>y cone f ! l>g] end4 ,! prism glasses are con/ruct$ on ! opposite pr9ciple4 ,! rays ( light ga!r$ by ! objective em]ge f ! eyepiece 9 a conv]g+ p5cil ( light small en\gh to ent] ! pupil ( ! eye1 ?us giv+ a l>g] field ( view2 !oretically1 n9e times ! area giv5 by ! old-/yle in/rum5t ( ! same p[]4 ,) ^! advantages1 h[ev]1 ! ,porro prism glass has n be5 f\nd 9 all respects satisfactory = field s]vice4 ,) a cle> atmosph]e & ! object :i* is be+ view$ well illum9at$1 x is di/9ctly sup]ior to ! ,galilean field-type glass 9 respect to light1 p[]1 & def9ition4 ,! prisms hav+ once be5 d]ang$1 h[ev] slightly1 satisfactory use ( ! glass c n be _h until ! prisms h be5 readju/$1 & until v rec5tly x 0 impracticable to h ?is done else:]e ?an at ! place ( manufacture ( ! glass4 ,illu/ration3 ,,fig4 #bi4--,porro prism4 ,,field ,,glasses4 ,! field glass or b9ocul> is a comb9ation ( two simil> telescopes & possesses me*anical adju/m5ts capable ( focus+ ! two telescopes simultane\sly or sep>ately1 dep5d+ ^u ! type consid]$4 ,field glasses are divid$ into two g5]al classes1 viz1 ! ,galilean glasses & ! ,porro prism glasses4 ,,prop]ties ,,( ,,telescopes ,,& ,,field ,,glasses4 ,telescopes & field glasses h f\r prop]ties1 viz1 p[]1 light1 field1 & def9ition4 ,^! prop]ties are express$ 9 t]ms ( ! correspond+ qualities ( ! unaid$ eye4 ,eyes are ( v diff]5t capabilities4 ,"s p h %ort sight :ile o!rs h f> sight4 ,!re are normal1 excell5t1 & weak eyes4 ,9 ! foll[+ discussion ! capabilities ( ! normal eye are assum$4 ,= ea* individual !re is a c]ta9 di/ance at :i* objects may be mo/ di/9ctly se54 ,?is is call$ ! visual di/ance4 ,) %ortsight$ eyes ?is di/ance is f #c to #f in*es2 ) normal eyes1 f #h to #ad in*es1 & ) f>sight$ eyes1 f #af to #bh in*es4 ,! capabilities ( ! normal unassi/$ eye may !re=e be express$ z foll[s3 ,p[]1 #a2 light1 #a2 field1 #de2 def9ition1 #dj to #c4 ,p[]4--,at ! visual di/ance1 all objects se5 by ! unaid$ normal eye appe> 9 _! natural size4 ,at less ?an ! visual di/ance !y appe> indi/9ct1 blurr$1 & imp]fectly def9$2 at great] ?an ! visual di/ance objects are cle> & well def9$1 b dim9i% 9 size1 ! m s z !y are f>!r remov$4 ,! ability ( a l5s to magnify ! app>5t diamet] ( an object is t]m$ its p[]4 ,! p[] ( a l5s is def9$ z ! ratio ( ! diamet] ( ! object z se5 ?r\gh ! l5s to ! diamet] z view$ by ! unaid$ eye4 ,! p[] is also def9$ z ! ratio ( ! focal di/ance ( ! object glass to t ( ! eyepiece4 ,! p[] ( a field glass c be r\ghly det]m9$ by focus+ ! in/rum5t on a wall or a range rod1 by look+ at ! object ?r\gh ! in/rum5t ) "o eye & at ! same object directly ) ! unaid$ eye4 ,a comp>ison ( ! diamet] ( ! two images gives ! ratio4 ,! p[] ( a telescope or a field glass c m accurately be measur$ by means ( a dynamet]1 :i* is a microscope :i* c be fitt$ ov] ! eyepiece end ( ! in/rum5t1 & :i* magnifies ! image4 ,! end ( ! dynamet] next to ! eyepiece ( ! in/rum5t is rul$ ) a s]ies ( l9es "o-hundr$? ( an in* ap>t4 ,on focus+ ! dynamet]1 ! image ( ! em]g+ p5cil appe>s z a %>ply def9$ r+ ( light ) ! magnifi$ scale ( ! dynamet] across x4 ,! numb] ( subdivisions cov]$ by ! diamet] ( ! r+ ( light is not$4 ,! diamet] ( ! object glass is simil>ly measur$ by means ( a pair ( divid]s & read to ! hundr$? "p ( an in*4 ,! ratio ( ! diamet] ( ! object glass to t ( ! image z se5 9 ! dynamet] gives ! p[] ( ! in/rum5t4 ,?is me?od is n applicable 9 ! case ( ! ,galilean telescope or ! field glass consi/+ ( two ,galilean telescopes1 due to ! fact t ! rays f ! eyepiece ( ! ,galilean telescope are div]g5t4 ,field glasses 9 :i* ! image appe>s magnifi$ f "o to six diamet]s are kn[n z l[-p[] glasses4 ,field glasses :i* produce an image magnifi$ ov] six diamet]s are t]m$ high p[]4 ,= ! m\nt$ man a glass ( b #d1 or at mo/ #f1 p[]s1 c be us$ ) advantage2 on foot1 ) free h&1 in/rum5ts ( n to exce$ #aj p[]s c be us$4 ,if m ?an #aj p[]s are desir$1 a hold] becomes necess>y1 & if ! hold] is int5d$ to be portable a great] p[] ?an #ej is n practicable1 z ! movem5t ( ! air or ! slighte/ t\* ( ! h& sets up vibrations t r5d] cle> vision impossible4 ,field glasses ) l[ magnify+ p[]1 :i* are usually pref]r$ by ord9>y obs]v]s1 h _! *ief value 9 ! comp>atively ext5sive field ( view2 !y %\ld be us$ to obs]ve ext5sive movem5ts1 :]e l>ge tracts ( c\ntry mu/ be tak5 9 "o field ( view or 9 sweep+ ! l&scape to f9d ! t5ts ( ! enemy1 _! wagons1 etc41 or o!r objects1 to be aft]w>ds m closely exam9$ ) ! telescope4 ,!y may be us$ on %ipbo>d or 9 boats1 :]e ! roll+ motion int]f]es ) ! use ( ! telescope2 also on horseback or 9 ha/y exam9ation made on foot or 9 trees1 & g5]ally = all obs]vations n critical or ^? to be made "u circum/ances :]e ! telescope c n be conv5i5tly h&l$4 ,! field glass ought to be held by bo? h&s :5 9 use1 & to /eady x ! arms %\ld be kept close to ! body4 ,= read+ signals at %ort ranges1 say1 up to #e miles1 ^! glasses are bett] ?an ! telescope4 ,flag signals h frequ5tly be5 read ) glasses ( ?is description at a di/ance ( #aj miles4 ,light4--,! illum9ation ( an object :5 obs]v$ ) ! unaid$ eye is impress$ ^u ! ret9a ) a brightness 9 /rict proportion to t ( ! object itself4 ,if an object be view$ "u equal illum9at+ conditions alt]nately ) ! nak$ eye & ) a glass1 ! brightness ( ! image se5 ) ! nak$ eye may be repres5t$ by #a1 :ile t ( ! image 9 ! glass w g5]ally diff]1 be+ great] or less4 ,! light ( ! telescope or field glass is express$ by ! numb] :i* %[s h[ _m times bright] ! object appe>s ?r\gh ! in/rum5t ?an to ! nak$ eye4 ,light is a function ( ! dim5sions ( ! object glass & ( ! p[] ( ! in/rum5t1 & is sometimes det]m9$ by divid+ ! squ>e ( ! objective ap]ture 7express$ 9 millimet]s7 by ! squ>e ( ! p[]4 ,! light ( a telescope or field glass c also be det]m9$ by means ( ! absorption app>atus %[n 9 figure #cj 7a7 7b7 7c74 ,?is absorption app>atus op]ates on ! pr9ciple ( view+ an object ?r\gh a p]fectly black liquid1 :i* absorbs all colors equally1 & ( increas+ ! ?ickness ( ! liquid lay] until ! object becomes invisible4 ,! ?ickness ( ! lay] ( liquid w !n be a measure ( ! relative brightness or int5sity ( ! illum9ation4 ,illu/ration3 ,,fig4 #cj7;a7 ,,fig4 #cj7;b7 ,,fig4 #cj7;c7 ,! app>atus consi/s ( two w$ge-%ap$ vessels1 made ( brass1 ) glass w9d[s 9 ! sides4 ,"o ( ^! vessels is %[n 9 p]spective 9 figure #cj;a4 ,! sides ,a & ! "o opposite are ( glass4 ,b is tubulure = fill+ ! app>atus1 & is /opp$ ) a cap4 ,! op]ation ( ! app>atus is %[n diagrammatically 9 figures #cj;b & #cj;c4 ,! edges ( ! two w$ges :i* come toge!r are divid$ into scales ( equal p>ts ( conv5i5t magnitude4 ,ea* scale beg9s ) z]o2 n at ! extreme po9t ( ! w$ge outside1 b at a po9t1 :i*1 all[+ = ! ?ickness ( ! glass sides1 is opposite ! po9t ( ! w$ge ( liquid inside4 ,x w be obs]v$ 9 figures #cj;b & #cj;c t ! sum ( any two adjac5t numb]s1 on ! respective scales1 ov] ! :ole ov]lapp+ portion ( ! w$ges1 is ! same4 ,?us 9 figure #cj;b x is #aa1 & 9 figure #cj;c x is #g4 ,^! figures measure ! relative ?ickness ( ! liquid lay]s 9 ! two respective sett+s ( ! app>atus4 ,suppose ! image is j oblit]at$1 :5 look+ ) ! unaid$ eye1 at ! sett+ %[n 9 figure #cj;b1 & :5 us+ ! glass at ! sett+ %[n 9 figure #cj;c4 ,?is w\ld mean t ! illum9at+ p[] ( ! glass is sev5-elev5?s4 ,9 us+ ! app>atus1 a focus+ clo?1 us$ by all photograph]s1 is useful 9 exclud+ /ray light4 ,field4--,ma9ta9+ ! head & eyes z motionless z possible1 ! field ( vision ( ! unaid$ eye or ! range )9 :i* objects c be p]ceiv$ by ! unaid$ eye v>ies accord+ to direction4 ,de ,s*we9itz gives ! foll[+ limits3 ,outw>d1 #ij2 outw>d & upw>d1 #gj2 upw>d1 #ej2 upw>d & inw>d1 #ee2 inw>d1 #fj2 inw>d & d[nw>d1 #ee2 d[nw>d1 #gb2 d[nw>d & outw>d1 #he4 ,x may be safely said t ! field or visual angle ( ! unaid$ eye = di/9ct vision is at lea/ #de 9 all directions4 ,! visual angle or field ( a field glass is always small]1 no field glass hav+ yet be5 design$ :i* c\ld equal ! field ( ! unaid$ eye4 ,! field ( a telescope or field glass c be/ be det]m9$ by ! use ( a transit or o!r in/rum5t us$ 9 measur+ horizontal angles4 ,! glass is plac$ ^u ! telescope ( ! transit 9 su* a way t ! axes ( collimation ( ! transit & ! telescope or field glass are p>allel4 ,! extreme limits ( ! field ( view are m>k$ & ! horizontal angle betwe5 ! m>k]s not$ on ! limb ( ! transit4 ,def9ition4--,"o ( ! *ief qualities ( ! eye is its p[] ( def9+ outl9es & details di/9ctly4 ,relative *>act]i/ics 9 ?is respect may be det]m9$ 9 v>i\s ways4 ,?us ! di/ance at :i* pr9t$ matt] c be read1 or ! details ( a di/ant object di/+ui%$1 w give a fair measure ( ! def9+ p[] ( ! eye2 b a bett] me?od is to express ! def9ition ( sight by angul> measurem5t--t is1 by ! det]m9ation ( ! smalle/ visual angle giv+ cle> results4 ,exp]i5ce tea*es t ?is angle ( ! normal eye 7) good light & favorable color conditions7 is ab\t #dj1 & x is !re=e possible to det]m9e ! smalle/ object :i* c j be se51 well def9$1 at an arbitr>y di/ance4 ,= in/ance1 at a di/ance ( #ae feet an object c be se5 :i* is "o-tw5tie? ( an in* high or broad2 at #cj feet di/ance1 consequ5tly1 ! object mu/ be twice ! size 7"o-t5? ( an in*7 to be se51 & s on relatively1 )9 limits1 z di/ance increases4 ,b z ! di/ance becomes great] %>pness ( vision is impair$ mat]ially by ! int]pos+ atmosph]e1 :ile x is also affect$ by color contra/s & conditions ( illum9ation4 ,x !re=e foll[s t at consid]able di/ances objects :i* subt5d a visual angle ( #dj are no long] cle>ly def9$ b become s only z ! angle approa*es #fj1 #abj1 #ahj1 or m4 ,! mo/ important & ess5tial quality ( a telescope or field glass is def9ition1 i4 e41 ! %>pness1 cle>ness1 & ! purity ( ! images se5 ?r\gh x4 ,to obta9 good def9ition x is necess>y t sph]ical & *romatic ab]ration be ov]come1 t ! poli% ( ! l5ses be z p]fect z possible1 t ! cem5t possess no inequalities1 & t ! l5ses be well focus$1 t !re be no dampness 9 ! int]ior ( ! tubes1 &1 g5]ally1 t ! in/rum5t be )\t optical defect4 ,faults 9 ?is direction are discov]$ at once by exam9ation ( def9ition1 :]eas 9 det]m9+ ! o!r con/ants !y are less noticeable4 ,9 comp>+ ! def9ition ( any two in/rum5ts x is ord9>ily necess>y only to scan di/ant objects & obs]ve to :at ext5t details may be di/+ui%$4 ,! foll[+ te/ may also be us$3 ,focus on pr9t$ matt] at a di/ance j beyond t at :i* p]fect cle>ness is giv5 & gradually approa* until ! lett]s are di/9ctly def9$4 ,! in/rum5t ) :i* ! pr9t c be read at ! greate/ di/ance has ! be/ def9ition4 ,to express def9ition z an absolute measure1 use in/ead ( pr9t$ matt]1 a :ite %eet ( pap] ^u :i* a s]ies ( heavy l9es are drawn at int]vals equival5t to _! ?ickness4 ,focus ^u ?is & gradually approa* f a po9t :]e ! impression ( a uni=m gray field ceases & ! black l9es & :ite int]vals beg9 to appe> di/9ct & def9$4 ,let ! di/ance ?us f\nd be #bj y>ds & ! ?ickness ( ! l9es & int]vals betwe5 !m "o-t5? in*4 ,! circumf]5ce ( a circle ) a radius ( #bj y>ds or #g1bjj t5?s in*es is #ad1djj by #c4adaf or #de1bdj t5? in*es2 b a circumf]5ce equals #cfj or 7#cfj by #fj by #fj7 #a1bif1jjj4 ,if1 !re=e1 #de1bdj t5?s in*es correspond to #a1bif1jjj1 !n #a t5? in* equals #a1bif1jjj divid$ by #de1bdj1 or #bh4f4 ,! def9ition is !re=e #bh4f1 or practically half a m9ute4 ,! capabilities ( glasses1 includ+ telescopes1 9 a g5]al way1 lie betwe5 ! foll[+ limits3 7#a7 ,p[] betwe5 #b & #a1jjj4 7#b7 ,light may be #j4ja to #bjj times t ( ! unaid$ eye4 7#c7 ,field measures 9 mo/ favorable case1 #aj2 9 ! mo/ unfavorable1 4#ja4 7#d7 ,def9ition v>ies betwe5 #dj & #j4a4 ,?us1 z a maximum1 an object may be se5 by means ( a telescope1 magnifi$ #a1jjj times1 #bjj times bright] & #djj times %>p] ?an ) ! nak$ eye4 ,if ^! advantages c\ld be fully utiliz$ = milit>y purposes ! use ( glasses w\ld be extraord9>y1 a p[] ( #a1jjj practically effect+ ! same purpose z ! approa* ( ! obs]v$ object to "o-?\s&? ( ! di/ance4 ,a ho/ile comm& #aj miles di/ant c\ld be se5 !oretically z well z if !y 7 only #ec feet away1 & ! slighte/ movem5t ( ea* s+le man w\ld become visible4 ,( c\rse no su* wond]ful effect is physically practicable1 & ! limit+ conditions increase greatly 9 proportion z ei!r "o or ! o!r ( ! qualities1 p[]1 field1 etc41 is especially s\ght4 ,:ile a/ronom]s require only t ! telescope be made z capable & p]fect z possible 9 an optical po9t ( view1 mak+ all o!r conditions subord9ate to ?is "o1 ! milit>y1 to :om ! glass is simply an accessory1 make o!r conditions ( ! fir/ importance4 ,! glass mu/ h suitable =m1 small volume1 little weight1 & t x may be us$ )\t support1 m\nt$ or dism\nt$1 & ! image mu/ appe> z look$ at by ! nak$ eye--t is1 n inv]t$4 ,! capability ( ! in/rum5t1 h[ev]1 is !reby mu* limit$2 great p[]s give pla9 images only ) relatively long tubes2 glasses mu/ be held ! /eadi] ! m !y magnify2 & ) increas+ p[] all vibrations become m tr\blesome & r5d] m9ute obs]vations v difficult or impossible4 ,! additional l5ses 9 t]re/rial telescopes some:at decrease p[] & affect also light & def9ition4 ,x is cle> !re=e t expectations ( a*iev+ great p[] %\ld n be ent]ta9$1 ! function ( field glasses be+ to br+ out & def9e objects :i* to ! nak$ eye appe> indi/9ct & d\btful4 ,! di/9ctness ) :i* any?+ c be se5 ?r\gh ! telescope dep5ds1 prim>ily1 ^u ! numb] ( /raight l9es ( light :i* are collect$ by x f e po9t ( ! object4 ,telescopes1 ! object glasses be+ equal 9 size1 dim9i% light z a g5]al rule 9 proportion z _! magnify+ p[] is great4 ,! mo/ p[]ful glasses are !re=e to be us$ = m9ute obs]vations on ! cle>e/ days or :5 !re is a /rong light ^u ! obs]v$ object4 ,:5 ! light is fad+ or !re is a little light ^u ! obs]v$ object ! cle>] view w be _h ) glasses ( l>ge field & l[ magnify+ p[]4 ,,field ,,glasses ,,& ,,telescopes ,,issu$ ,,by ,,! ,,signal ,,corps4 ,! ,signal ,corps issues f\r /&>d field glasses1 viz1 ,type ,a1 ,type ,b1 ,type ,c1 ,type ,d4 ,field glasses issu$ by ! ,signal ,corps are n suppli$ = ! p]sonal use ( an (fic] & w n be us$ 9 lieu ( ! (fic]'s p]sonal field glass prescrib$ by p>agraph #ig1 ,g5]al ,ord]s1 #afi1 ,w> ,dep>tm5t1 #aijg 7,p>4 #a1 ,g4 ,o4 #af1 ,w> ,dept41 #aiaj74 ,"u p>agraph #aehb1 ,army ,regulations1 z am5d$ by p>agraph ,i1 ,g5]al ,ord]s1 ,no4 #bjg1 ,w> ,dep>tm5t1 ,octob] #af1 #aiji1 ! ,signal ,corps w sell field glasses to (fic]s ( ! army = _! p]sonal use4 ,application = ! pur*ase ( field glasses %\ld be address$ to ! ,*ief ,signal ,(fic] ( ! ,army1 ,wa%+ton1 ,d4 ,c41 inclos+ po/-(fice money ord] or *eck on ! ,treasur] or ,assi/ant ,treasur] ( ! ,unit$ ,/ates = ! am\nt1 payable to ! ,disburs+ ,(fic]1 ,signal ,corps1 & ,signal ,corps ,=m ,no4 #bdj accompli%$ 9 duplicate4 ,! ,gov]nm5t does n pay transportation *>ges = ! %ipm5t ( articles sold to (fic]s4 ,field glasses are s5t f ! ,signal ,corps ,g5]al ,supply ,depot1 ,=t ,wood1 ,new ,york ,h>bor1 by express1 *>ges collect1 unless pur*ase reque/ is accompani$ by funds s t field glasses may be s5t by regi/]$ mail4 ,=w>d+ by regi/]$ mail is some:at *eap] ?an by express1 & ! am\nt ( po/age requir$ is #dj c5ts = ,type ,d glass1 #df c5ts = ,types ,a & ,b1 & #gd c5ts = ,type ,c4 ,express *>ges dep5d ^u ! di/ance f ,new ,york4 ,! ,signal ,corps has pur*as$ _m samples ( field glasses f v>i\s manufactur]s ) a view ( te/+ _! suitability = ! milit>y s]vice4 ,^! samples may be exam9$ by (fic]s ( ! army at ! signal (fice 9 ,wa%+ton4 ,among ^! samples !re are _m excell5t glasses especially suitable = ! milit>y s]vice1 b ! high] grades are too exp5sive = g5]al issue to l9e organizations 9 l>ge quantities4 ,(fic]s desir+ an especially f9e field glass %\ld inspect ! samples ref]r$ to2 ^!1 h[ev]1 are n = sale by ! ,gov]nm5t1 b in=mation w be suppli$ conc]n+ deal]s & co/4 ,no advice or fix$ rule c be /at$ z to :at con/itutes ! mo/ suitable *>act]i/ics ( a field glass4 ,no s+le field glass c furni% maximum results "u all conditions on acc\nt ( v>y+ conditions ( ! atmosph]e4 ,a high-p[] glass is unsuitable = use at night1 hazy atmosph]e1 or = use ( a m\nt$ man :]e ! glass c n be re/$ aga9/ a firm support4 ,a l[-p[] glass ) l>ge object l5s to p]mit z mu* light z possible is a necess>y condition = use at night4 ,! d\ble p[] glass :i* is issu$ z a "p ( ! visual signal+ outfits 0 design$ = ! milit>y s]vice z a compromise = conflict+ conditions4 ,a brief description ( ! field glasses issu$ by ! ,signal ,corps1 toge!r ) ! co/ ( ! same1 is giv5 bel[4 ,type ,a3 ,?is glass is ! curr5t result ( ! ef=ts ( ! ,signal ,corps to provide a field glass t w meet ! greate/ v>iety ( conditions1 & insure effici5t s]vice to ! greate/ numb] ( milit>y obs]v]s4 ,x is really two glasses 9 "o--a day glass ( m$ium p[]1 & a night glass ( l[ p[]4 ,illu/ration3 ,,fig4 #ca4--,type ,a4 ,%[+ ! field glass & case ) sl+ cord1 %\ld] /raps1 belt loops1 & compass4 ,x is to be cle>ly und]/ood t :ile ?is glass is consid]$ sup]ior = mod]ate ranges1 x does n replace1 "u special conditions1 = long ranges1 ei!r ! porro prism glass or ! telescope4 ,:5 held z %[n 9 figure #cb ) ! tubes drawn out ab\t #a in* to secure prop] focus1 ! glass has a p[] ( ab\t #e4f diamet]s1 & a field ( ab\t #e4d degrees4 ,illu/ration3 ,,fig4 #cb--,signal ,corps field glass1 ,type ,a4 ,if ! glass is turn$ into ! position %[n 9 figure #cc1 ! small plus l5ses1 j 9 front ( ! eye pieces1 drop automatically into position & r$uce ! p[] to #c4h diamet]s1 & increase ! field to #h4c degrees4 ,?is position requires a diff]5t adju/m5t1 ! tubes be+ drawn out ab\t "o-?ird ( an in* to get ! prop] focus4 ,x w be obs]v$ 9 ! illu/rations t ! re> b> ( ! frame is n only lett]$ to indicate :i* p[] is be+ us$1 b ! b> itself is %ap$ ) a hump on "o side1 & holl[$ on ! o!r4 ,:5 ! hump is up1 ! l[ p[] is 9 use4 ,?is is to facilitate adju/m5t 9 ! d>k4 ,! action ( ! small automatic l5ses is free & positive4 ,nei!r ! eyepieces nor ! sections conta9+ ! small l5ses %\ld be unscrew$1 except 9 case ( necessity1 & !n n by unskill$ h&s4 ,illu/ration3 ,,fig4 #cc4--,signal ,corps field glass1 ,type ,a4 ,! frame1 ( alum9um & brass1 is composite1 to give lightness & /r5g?2 & :ile x is con/ruct$ to )/& ! r\gh h&l+ ( field s]vice1 no field glass is pro( aga9/ c>eless or wanton treatm5t4 ,! tubes are cov]$ ) tan lea!r1 & a r\nd sl+ cord1 braid$ f f\r /r&s ( pliable tan lea!r1 is fa/5$ by snaps to eyes 9 ! frame4 ,! case is ( tan calfsk91 provid$ ) %\ld] /rap1 & has an effici5t small compass set into ! cov]4 ,two loops are sew$ to ! back ( ! case s t x may be worn on a belt4 ,! glass1 complete ) case1 cord1 & /raps1 weighs #ba4e ounces4 ,two ( ^! glasses are issu$ to ea* company ( infantry & coa/ artill]y1 ,philipp9e ,sc\ts1 & ,signal ,corps1 & to ea* troop ( cavalry = use 9 in/ruction 9 visual signal+4 ,bel[ is a brief description ( ! type ,a glass4 ,magnification1 #c & #e diamet]s2 ,galilean type2 object l5s1 #a in*es2 tan lea!r f9i%2 tan lea!r c>ry+ case ) compass2 weight ( glass1 complete1 ) case1 cord1 & /rap1 #be ounces4 ,at a di/ance ( #a1jjj y>ds ! field ( view includes a diamet] ( #abc y>ds = ! #c p[]1 & #gc y>ds = ! #e p[]4 ,l5g? ( glass clos$1 #d in*es4 ,?is glass is issu$ z a "p ( ! visual signal+ kit to ea* company ( infantry1 coa/ artill]y1 & ,philipp9e ,sc\ts1 troop ( cavalry1 ma*9e-gun platoon1 & ,signal ,corps field company4 ,price1 #ab4ae4 ,! late/ issue ( ?is glass kn[n z ! ,type ,a1 model #aiaj1 includes provision = int]pupill>y adju/m5t1 ! two b>rels be+ h+$ to accommodate ! glass to ! di/ance betwe5 ! pupils ( ! eye4 ,! price ( ! model #aiaj glass is #ad4ge4 ,type ,b3 ,?is field glass is simil> 9 appe>ance & con/ruction to ! ,type ,a glass1 & is issu$ to ! field artill]y organizations ^u requisition4 ,! foll[+ is a brief description3 ,magnification1 #d & #f diamet]s2 ,galilean type2 object l5s1 #a in*es2 int]pupill>y adju/m5t2 tan lea!r f9i%2 tan lea!r c>ry+ case ) compass2 weight ( glass1 complete1 ) case1 cord1 & /raps1 #bf ounces2 l5g? ( glass clos$1 #d in*es4 ,at a di/ance ( #a1jjj y>ds ! field ( view includes a diamet] ( #ij y>ds = ! #d p[]1 & #fj y>ds = ! #f p[]4 ,?is glass is issu$ z a "p ( ! fire-control equipm5t to field artill]y4 ,price1 #ag4ej4 ,type ,c3 ,! type ,c is a high p[] glass ( ! porro prism type & is issu$ only to c]ta9 organizations ( ! field artill]y1 ,signal ,corps1 & to all ma*9e-gun platoons4 ,description4--,magnification1 #aj diamet]s2 prismatic type2 object l5s1 #a in*es2 int]pupill>y adju/m5t2 tan lea!r f9i%2 sun%ade2 tan lea!r c>ry+ case2 weight ( glass1 complete1 ) case1 cord1 & /raps1 #df ounces2 l5g? ( glass clos$1 #g in*es4 ,at a di/ance ( #a1jjj y>ds ! field ( view includes a diamet] ( #hj y>ds4 ,?is glass is issu$ to reconnaissance (fic]s ( field artill]y4 ,price1 #ci4ij4 ,type ,d3 ,pur*ase has be5 made = deliv]y 9 ! ne> future ( a supply ( a new type ( high p[] prismatic field glass = sale & issue4 ,?is new type ( glass1 to be kn[n z type ,d1 is consid]ably small] ?an ! type ,c glass1 z is %[n by figure #cd4 ,! glass 9 a tan-color$ c>ry+ case weighs #ae ounces1 ! field glass )\t ! case weigh+ b #i ounces4 ,! magnification is #h p[]s & ! field ( view 7) bo? eyes7 #e #dj4 ,! e/imat$ co/ w be #bg4 ,,telescopes ,,issu$ ,,by ,,! ,,signal ,,corps4 ,type ,a3 ,?is glass complete consi/s ( a #b-;in* prism t]re/rial telescope1 p[]s #ah & #bd1 ) alt-azimu?1 fold+ tripod1 & c>ry+ case4 ,type ,b3 ,?is telescope is a #ai-bg p[]1 #b-;draw t]re/rial telescope1 9 lea!r c>ry+ case ) sl+4 ,! lea!r c>ry+ case also includes a hold] :i* c be screw$ into a tree1 po/1 or o!r /ation>y wood5 object4 ,,g5]al ,,specification ,,no4 #bfc4 ,revis$ ,febru>y #aj1 #aiaj4 ,,s]vice ,,field ,,glasses4 #a4 ,prelim9>y4--,?is specification cov]s ! design & con/ruction ( field glasses1 types ,a & ,b1 ea* hav+ two p[]s z h]e9aft] specifi$4 #b4 ,sample4--,! bidd] %all furni% ) 8 proposal a sample ( ! glass :i* he w supply1 & aw>d w be made aft] comp>ison ( ! samples ) models on file 9 ! (fice ( ! ,*ief ,signal ,(fic]4 ,! mak] w be all[$ to exam9e ! model glasses 9 detail 9 ! (fice ( ! ,*ief ,signal ,(fic] ( ! ,army1 ,wa%+ton1 ,d4 ,c4 #c4 ,inspection & te/4--,:5 ! ord] "u ?is specification is complete1 ! contractor w notify ! ,*ief ,signal ,(fic] ( ! ,army1 :o w cause an inspection to be made4 ,x %all be ! duty ( ! contractor to rem$y any defects po9t$ out by ! inspector1 & ! contractor w be held acc\ntable = any imp]fections :i* ! inspector may h ov]look$4 ,illu/ration3 ,,fig4 #cd4--;,field glasses1 ,types ,c & ,d4 ,! ,*ief ,signal ,(fic] ( ! ,army res]ves ! "r to inspect any or all processes ( manufacture1 & unsatisfactory mat]ial w be m>k$ = rejection by ! inspector be=e1 dur+1 or aft] assembly1 z occasion may arise4 ,ea* glass w be te/$ = p[]1 field1 def9ition1 & light4 ,any glass :i* is n ! equal ( ! sample & model 9 all respects w be reject$4 ,! prop]ties above enum]at$ w be te/$ z foll[s3 7a7 ,p[]3 ,9 te/+ = p[] ! glass w be plac$ ^u a firm support ab\t ! height ( ! eye & direct$ ^u a range rod1 accurately divid$ into divisions ( #a foot1 ) alt]nate divisions color$ r$ & :ite1 respectively4 ,! rod %\ld be plac$ approximately #ajj feet f ! glass 9 a good light & ) /rongly contra/$ backgr\nd4 ,! rod is obs]v$ ?r\gh ! glass ) "o eye & at ! same "t ) ! o!r eye unaid$4 ,an accurate comp>ison ( ! two images by means ( ! rod scale det]m9es ! magnify+ p[] ( ! glass4 7b7 ,field3 ,! field w be det]m9$ by ! use ( a transit or any o!r in/rum5t adapt$ to ! measurem5t ( horizontal angles4 ,! glass w be plac$ ^u ! telescope ( ! transit 9 su* a way t ! axes ( collimation ( ! telescope & field glass b>rels are p>allel4 ,! extreme limits ( ! field ( view ( ! glass are m>k$ 9 a conv5i5t way & ! horizontal angle ( view accurately measur$ ) ! transit4 7c7 ,def9ition3 ,9 det]m9+ ! def9ition ( ! glass express$ 9 units 7seconds7 a t>get w be provid$ ) a numb] ( l9es "o-t5? in* ?ick ) "o-t5? in* spaces betwe5 !m drawn on a piece ( heavy :ite pap]4 ,at a c]ta9 di/ance ?is t>get w appe> uni=mly gray :5 view$ ?r\gh ! glass4 ,! inspector w gradually approa* ! t>get1 focus+ ! glass until he rea*es ! mo/ di/ant po9t f ! t>get :]e ! uni=m field ceases & ! black & :ite int]vals appe> di/9ct & def9$4 ,assume ! di/ance ?us f\nd to be #bj y>ds & ! ?ickness ( ! l9es & int]vals betwe5 !m "o-t5? in*4 ,! circumf]5ce ( a circle ) a radius ( #bj y>ds or #g1bjj t5?s in*es is #ad1djj by #c4adaf1 or #de1bdj t5?s in*es2 b a circumf]5ce equals #cfj1 or 7#cfj by #fj by #fj7 #a1bif1jjj seconds4 ,if1 !re=e1 #de1bdj t5?s in*es correspond to #a1bif1jjj seconds1 !n "o-t5? in* equals #a1bif1jjj divid$ by #de1bdj1 or #bh4f seconds4 ,! def9ition is !re=e #bh4f seconds1 or practically half a m9ute4 ,! def9ition %\ld be z foll[s3 ,= #f4e p[] glass #cj seconds4 ,= #e4e p[] glass #ce seconds4 ,= #d4e p[] glass #dj seconds4 ,= #c4e p[] glass #ee seconds4 7d7 ,light3 ,! light ( a field glass is express$ by a numb] :i* is ! ratio ( ! am\nt ( light :i* rea*es ! eye ?r\gh ! glass to ! am\nt :i* ent]s ! eye unaid$4 ,?is comp>ison w be rea*$ by means ( ! absorption app>atus furni%$ by ! ,signal ,corps4 ,?is app>atus consi/s ( two w$ge-%ap$ vessels made ( brass ) glass w9d[s 9 ! sides1 & are fill$ ) a p]fectly black liquid4 ,! sky l9e is fir/ view$ ?r\gh ! app>atus ) ! nak$ eye & ! in/rum5t adju/$ to limit ( visibility4 ,! read+ ( ! scale is !n not$4 ,! sky l9e is aga9 obs]v$1 us+ ! glass1 b 9 o!r respects z be=e1 & a second scale read+ obta9$4 ,! ratio ( ^! read+s measure ! illum9at+ p[] ( ! glass :i* mu/ con=m to ! /&>d sample4 #d4 ,s]vice field glass1 type ,a4--7a7 ,?is glass %all con=m 9 g5]al to ! model1 n[ on file 9 ! (fice ( ! ,*ief ,signal ,(fic] at ,wa%+ton4 ,! arrangem5t = *ang+ automatically f ! l[ p[] to ! high p[]1 & vice v]sa1 by ! int]position ( ! plus l5s at ! prop] di/ance 9 front ( ! eyepiece1 mu/ be /rictly adh]$ to4 7b7 ,! l[ p[] %all be approximately #c diamet]s & ! high p[] %all be approximately #e diamet]s4 ,! figure ( m]it giv5 by multiply+ ! numb]s ( diamet]s p[] by ! numb] ( degrees ( field w be consid]$ 9 ! exam9ation ( samples1 along ) ! o!r prop]ties ( light1 %>pness ( def9ition1 & g5]al excell5ce4 7c7 ,! tubes1 frame1 & metal fitt+s %all be ( alum9um or an alum9um alloy1 ) ! exception t su* metal p>ts z 9 ! op9ion ( ! mak] require great] /r5g? may be made ( brass4 ,tubes %all be held firmly 9 ! frame1 s+le draw1 ! draw action to be ?r\gh a be>+ surface ( at lea/ five-eigh?s ( an in* ( be/ black felt1 p]fectly fitt$ s z to pres]ve p]fect alignm5t4 ,! ext]ior metal p>ts1 except :]e lea!r cov]$1 mu/ be giv5 ! be/ & mo/ durable1 lu/]less black f9i%4 ,! tubes & %ades w be neatly cov]$ ) be/ quality tann$ calfsk91 ! lea!r to be sew$ on1 & ! seams to lie flat next to ! focus+ /&>d4 ,! int]ior ( all p>ts to be pa9t$ a p]fectly dead black4 ,! sun%ades1 :5 drawn out1 %all project at lea/ five-eigh?s ( an in* & n ov] #a in* beyond ! edge ( ! cell4 ,! focus+ screw & /&>d %\ld foll[ closely t ( ! sample1 except t ! mill$ focus+ disk %\ld h a face z ne>ly "o-half in* wide z possible & ! mill+ %\ld be %>p]4 ,9 addition to ! diaphragm ^u :i* ! automatic l5s is m\nt$1 !re %all be two diaphragms 9 ea* tube1 s situat$ & s proportion$ z to cut (f all /ray light & all int]nal reflections4 ,! crossb> support+ ! draw tubes %\ld be %ap$ & engrav$ exactly z f\nd 9 ! model4 7d7 ,! l5ses mu/ be entirely free f me*anical defects1 su* z specks1 air bubbles1 etc42 mu/ be free f int]ior /ra91 & mu/ be gr\nd f ! be/ obta9able glass = ! purpose1 select$ = g5]al transp>5cy1 z colorless z possible1 p]fectly gr\nd & poli%$1 & accurately c5t]$4 ,! object l5ses %all be composite1 a*romatic1 & well correct$ = sph]ical ab]ration1 ) a cle> ap]ture ( at lea/ #a in*es1 & n exce$+ #a-e_/h in*es4 ,bidd]s w /ate ! numb] & %ape ( ! pieces us$ to make up ?is l5s4 ,! comp\nd l5ses may be ei!r cem5t$ toge!r ) ,canada balsam1 or left uncem5t$1 z ! mak] may deem be/ = durability & optical p]=mance1 b if left uncem5t$ ! compon5ts %all h a p]man5t m>k to indicate _! prop] positions 9 ! cell4 ,! eyepieces %all consi/ ( a s+le d\ble concave l5s hav+ a cle> ap]ture ( n less ?an ?ree-eigh?s ( an in* & n m ?an "o-half ( an in*4 7e7 ,! sl+ cord atta*$ to eyes 9 ! frame by means ( brass snaps ) black burn$ f9i% %all be r\nd & braid$ f f\r /r&s ( pliable tan lea!r1 & %all h a diamet] ( at lea/ "o-eigh? ( an in* & n ov] "o-six? ( an in*4 7f7 ,! case & /rap mu/ be exactly l sample1 & ( ,no4 #a /ock4 ,c>e mu/ be tak5 to put 9 only compasses t are 9 p]fect condition4 ,! /rap buckle mu/ be ( brass4 ,! glass1 :5 clos$1 mu/ n exce$ #d in*es 9 l5g?1 & ! glass1 case1 cord1 & /rap1 complete1 mu/ n exce$ #be ounces 9 weight4 7g7 ,! frame %all be con/ruct$ ) jo9t$ b>s = int]pupill>y adju/m5t4 #e4 ,s]vice field glass1 type ,b4--7a7 ,! requirem5ts ( "p #d1 s]vice field glass1 type ,a1 ( ?is specification1 %all be foll[$ 9 ! design & con/ruction ( ! type ,b glass 9 s f> z applicable4 7b7 ,p[]3 ,! l[] p[] %all be approximately #d & ! high #f diamet]s4 7c7 ,object l5ses3 ,^! %all h a cle> ap]ture ( at lea/ #a in*es diamet]4 7d7 ,case3 ,case & c>ry+ /rap %all be furni%$ z requir$ 9 "p #d ( ?is specification4 7e7 ,?is glass %all be con/ruct$ ) jo9t$ b>s = int]pupill>y adju/m5t4 7f7 ,! sun%ade1 :5 drawn out1 %all project n less ?an ?ree-eigh?s ( an in* & n m ?an #a in* beyond ! edge ( ! cell4 #f4 ,m>k+4--,glasses furni%$ "u ?is specification %all be m>k$ on "o b>rel ) ! words ,signal ,corps1 ,u4 ,s4 ,army1 & on ! o!r b>rel ,s]ial ,no4 ----4 ,s]ial numb]s w be furni%$ ) ! ord]4 ,if n furni%$ ! contractor at ! "t ! ord] is plac$1 ! ,disburs+ ,(fic] ( ! ,signal ,corps %\ld be call$ ^u = same1 & ! numb]s & o!r m>k+ plac$ on ! glasses prior to ! deliv]y ( ! ord]4 ,,james ,,all51 ,brigadi]-,g5]al1 ,*ief ,signal ,(fic] ( ! ,army4 ,,signal ,,(fice1 ,electric & ,telegraph ,division4 99 99 99 99 99 ,transcrib]'s ,notes3 ,!re is no figure #be 9 ?is text4 ,! numb]+ goes f figure #bd to figure #bf4 ,page #bc1 porportions *ang$ to proportions 79 prop] proportions7 ,page #ajf1 eng9ee] *ang$ to eng9e] 7a ,fr5* eng9e]7 ,page #abf1 op5+ bracket add$ to subtitle 7,revis$ ,febru>y #aj1 #aiaj47