,,a/ronomy ,,= ,,"y ,,folks ,illu/ration3 ,,nor!rn ,,portion ,,( ,,! ,,moon ,,at ,,la/ ,,qu>t] ,tak5 ) #ajj-;in* ,hook] ,telescope ( ! ,mt4 ,wilson ,obs]vatory 7,see ,*apt] ,,xxi7 ,,a/ronomy = ,,"y ,,folks ,,by ,,isabel ,,m>t9 ,,lewis1 ,a4 ,m4 7,connect$ ) ! ,nautical ,almanac ,(fice ( ! ,u4 ,s4 ,naval ,obs]vatory7 ,,new ,,york ,,duffield ,,& ,,company #aibb ,copyright1 #aiba1 by ,,! ,,c5tury ,,company ,copyright1 #aibb1 by ,,duffield ,,& ,,company ,pr9t$ 9 ,u4 ,s4 ,a4 ,,cont5ts ,,*apt] ,,page ,preface xiii ,i4 ,! ,con/ellations #c ,,ii4 ,janu>y #ae ,,iii4 ,febru>y #ba ,,iv4 ,m>* #bh ,v4 ,april #ce ,,vi4 ,may #da ,,vii4 ,june #di ,,viii4 ,july #ef ,,ix4 ,augu/ #fd ,x4 ,septemb] #ga ,,xi4 ,octob] #gh ,,xii4 ,novemb] #hd ,,xiii4 ,decemb] #ij ,,xiv4 ,/>s ( ! ,s\!rn ,hemisph]e #if ,,xv4 ,! ,milky ,way or ,galaxy #ajg ,,xvi4 ,! ,surface ( ! ,sun #aac ,,xvii4 ,! ,sol> ,sy/em #aai ,,xviii4 ,! ,orig9 ( ! ,e>? #abg ,,xix4 ,jupit] & ,8 ,n9e ,moons #aci ,,xx4 ,! ,r+s & ,moons ( ,saturn #adh ,,xxi4 ,is ! ,moon a ,dead ,_w #aef ,,xxii4 ,comets #afe ,,xxiii4 ,meteorites #agc ,,xxiv4 ,! ,e>? ,z a ,magnet #ahc ,,xxv4 ,"s ,effects ( ! ,e>?'s ,atmosph]e ,^u ,sunlight #aic ,,xxvi4 ,keep+ ,track ( ! ,moon #bjg ,,xxvii4 ,! ,motions ( ! ,heav5ly ,bodies #baf ,,xxviii4 ,! ,evolution ( ! ,/>s--,f ,r$ ,giants to ,r$ ,dw>fs #bbe ,,xxix4 ,d\ble & ,multiple ,/>s #bcj ,,xxx4 ,a/ronomical ,di/ances #bda ,,xxxi4 ,"s ,a/ronomical ,facts ,wor? ,rememb]+ #bej ,,illu/rations ,,page ,nor!rn ,portion ( ! ,moon at ,la/ ,qu>t] ,frontispiece ,! ,great ,h]cules ,clu/]--,a ,univ]se ( ,suns fac+ page #ef ,a ,d>k ,nebula3 ,! ,d>k ,bay or ,d>k ,horse ,nebula 9 ,orion fac+ page #aaj ,a4 ,v5us4 ,b4 ,m>s4 ,c4 ,jupit]4 ,d4 ,saturn fac+ page #abb ,spiral ,nebula 9 ,canes ,v5atici fac+ page #baf ,spiral ,nebula 9 ,&rom$a ,view$ ,edgewise fac+ page #bbb ,,li/ ,,( ,,tables ,,page ,i4 ,! ,pr9cipal ,elem5ts ( ! ,sol> ,sy/em #bfa ,,ii4 ,! ,satellites ( ! ,sol> ,sy/em #bfb ,,iii4 ,! ,tw5ty ,brighte/ ,/>s 9 ! ,heav5s #bfc ,,iv4 ,a ,li/ ( ! ,pr9cipal ,con/ellations #bfd-bfe ,v4 ,pronunciations & ,mean+s ( ,names ( ,/>s & ,con/ellations #bff-bfg ,,preface ,a/ronomy1 x has be5 said1 is ! olde/ & ! noble/ ( ! sci5ces4 ,yet x is "o ( ! few sci5ces = :i* mo/ pres5t-day educators seem to f9d little1 if any1 room 9 _! curriculum ( /udy = ! "y1 9 spite ( its high cultural value4 ,x is1 we are told1 too ab/ruse a subject = ! y\?ful /ud5t4 ,?is is d\btless true ( !oretical or ma!matical a/ronomy & ! practical a/ronomy ( ! navigator1 surveyor & eng9e]1 b x is n true ( g5]al1 descriptive a/ronomy4 ,!re are _m diff]5t aspects ( ?is _m-sid$ sci5ce1 & "s ( ! simple/ & gr&e/ tru?s ( a/ronomy c be grasp$ by ! intellig5t *ild ( twelve or f\rte5 ye>s ( age4 ,m]ely z a bran* ( nature /udy ! *ild %\ld h "s k ( ! sun1 moon1 />s & planets1 _! motions & _! physical features1 = !y are z truly a "p ( nature z are ! birds1 trees & fl[]s1 & ! man1 woman or *ild :o goes =? b5ea? ! />-lit heav5s at night absolutely bl9d to ! wond]s & beauties ( ! univ]se ( :i* he is a "p1 loses z mu* z ! "o :o walks ?r\gh field or =e/ ) no ?\ght ( ! beauties ( nature t surr\nd him4 ,! a/ronom] is ! pione] & explor] ( today 9 realms unkn[n j z ! pione]s & explor]s ( sev]al c5turies ago 7 to "s ext5t a/ronom]s z !y sail$ unkn[n seas & trav]s$ unexplor$ regions4 ,z ! ye>s pass by ! a/ronom] ext5ds m & m 8 explorations ( ! univ]se & br+s back among ! fruits ( discov]y measures ( giant suns & e/imates ( ! =m & ext5t ( ! univ]se1 views ( :irl+1 see?+ nebul1 my/]i\s d>k cl\ds drift+ ?r\gh space1 trem5d\s sol> upheavals or glimpses ( /rangely m>k$ surfaces ( ne>by planets4 ,9 ! foll[+ pages ! au?or has endeavor$ to tell 9 words n beyond ! compreh5sion ( ! av]age f\rte5-ye>-old *ild some?+ ( ! nature ( ! heav5ly bodies4 ,9 ,"p ,i an ef=t is made to make ! *ild famili> ) ! />s by indicat+ :5 & :]e !y c be f\nd 9 ! e>ly ev5+ h\rs4 ,9 addition to id5tify+ ! pr9cipal con/ellations & _! brighte/ />s by means ( diagrams an attempt has be5 made to acqua9t ! *ild ) ! mo/ int]e/+ rec5t discov]ies t h be5 made conc]n+ ! pr9cipal />s or objects 9 ea* gr\p z well z ) "s ( ! /ories & leg5ds t h be5 associat$ ) ^! gr\ps ( />s = c5turies1 & t h be5 h&$ d[n 9 ! folk-lore ( all nations4 ,*apt]s #b-ac1 inclusive1 appe>$ orig9ally ) diagrams simil> to ^? %[n "h1 "u ! dep>tm5t ( ,nature & ,sci5ce = ,"y ,folk 9 ,/4 ,ni*olas f ,may1 #aiba1 to ,april1 #aibb1 inclusive4 ,! ,introductory ,*apt] & ,*apt]s #ad & #ae1 on ! ,milky ,way & ,/>s ( ! ,s\!rn ,hemisph]e1 respectively1 are publi%$ "h = ! fir/ "t1 z is also ! *apt] 9 ,"p ,,ii on ! ,evolution ( ! ,/>s f ,r$ ,giants to ,r$ ,dw>fs1 :i* gives ! ord] ( ! evolution ( ! />s z n[ accept$ z a result ( ! brilliant a/ronomical rese>*es ( ,dr4 ,h5ry ,norris ,russell ( ! ,unit$ ,/ates & ,pr(4 ,a4 ,s4 ,edd+ton1 ( ,engl&4 ,! rema9+ *apt]s 9 ,"p ,,ii h be5 *os5 f a s]ies ( articles t h appe>$ 9 ,sci5ce & ,inv5tion1 =m]ly ,! ,electrical ,exp]im5t]1 9 ! pa/ f\r ye>s1 & h be5 consid]ably revis$ & 9 "s p>ts rewritt5 to adapt !m to ! und]/&+ ( m y\?ful read]s4 ,^! *apt]s deal ) a v>iety ( a/ronomical subjects ( g5]al popul> int]e/ & an ef=t has be5 made to select subjects t w\ld cov] z wide an a/ronomical field z possible 9 a limit$ space4 ,! au?or's aim has n be5 to write a text-book ( a/ronomy or to treat 9 detail ( any "o aspect ( ?is ext5sive sci5ce1 b simply to give ! av]age *ild "s g5]al k ( ! nature ( ! heav5ly bodies1 bo? ^? t =m a "p ( our own sol> sy/em & ^? t lie 9 ! dep?s ( space beyond4 ,x has be5 necess>y to write v briefly1 & we feel inadequately1 ( _m topics ( special int]e/ su* z ! sun & moon4 ,books h be5 writt5 on ^! two subjects alone z well z ^u su* subjects z ,m>s1 eclipses1 comets1 meteors1 etc41 b ! object has be5 to acqua9t ! *ild ) ! out/&+ features ( a v>iety ( cele/ial objects r ?an to treat ( a few 9 detail4 ,if ! writ] succe$s 9 ar\s+ ! *ild's int]e/ 9 ! />s s t he may look =? ) intellig5ce at ! heav5s & greet ! />s z fri5ds & at ! same "t grasps "s ( ! simple/ & mo/ fundam5tal ( a/ronomical tru?s su* z ! di/9ction betwe5 />s & planets1 ! motions ( ! heav5ly bodies & _! relative di/ances f u & ! place ( our own planet-_w 9 ! univ]se1 ?is book w h s]v$ its purpose4 ,,a/ronomy ,,= ,,"y ,,folks ,! heav5s decl>e ! glory ( ,god1 & ! firmam5t %[e? ,8 h&iwork4 ,psalm ,,xix4 ,i ,,! ,,con/ellations ,can/ ?\ b9d ! sweet influ5ces ( ! ,pleiades ,or loose ! b&s ( ,orion8 ,can/ ?\ br+ =? ,mazz>o? 9 8 season ,or can/ ?\ guide ,arcturus ) 8 sons8 --,,book ,,( ,,job4 ,:o w\ld n l to "k ! />s & con/ellations by _! names & 9 _! seasons z we "k ! birds & ! trees & ! fl[]s1 to recognize at _! return1 ye> by ye>1 ,sirius & ,spica1 ,arcturus & ,ant>es1 ,vega & ,altair1 to "k :5 ,ursa ,major sw+s high ov]head & ,orion s9ks to re/ b5ea? ! we/]n horizon1 :5 ,leo comes into view 9 ! ea/ or ! ,nor!rn ,cr[n lies ov]head8 ,(t5 we deprive ourselves ( ! pleasure ( mak+ fri5ds ) ! />s & %ut our eyes to ! glories ( ! heav5s above because we d n realize h[ simple a matt] x is to become acqua9t$ ) ! v>i\s gr\ps ( />s z !y cross our m]idian1 "o by "o1 day aft] day & mon? aft] mon? 9 ! same ord]ly sequ5ce4 ,:5 ! rob9 returns once m to ne/ 9 ! same or*>d 9 ! spr+ "t1 ,leo & ,virgo may be se5 ris+ above ! ea/]n horizon 9 ! e>ly ev5+ h\rs4 ,:5 ! fir/ sn[ flies 9 ! late fall & ! birds h all gone s\?w>d ! belt ( ,orion appe>s 9 ! ea/ & ,cygnus dips l[ 9 ! we/4 ,:5 we once come to "k brilliant blue-:ite ,vega1 ruddy ,arcturus1 gold5 ,capella & sp>kl+ ,sirius we wat* = !m to return ea* 9 its prop] season & greet !m z old fri5ds4 ,9 ! foll[+ pages we give = ea* mon? ! con/ellations or />-gr\ps t are ne>e/ to our m]idian1 t is1 t lie ei!r due nor? or due s\? or exactly ov]head 9 ! e>ly "p ( ! mon? & ! e>ly "p ( ! ev5+4 ,we d n ne$ to />t our /udy ( ! con/ellations 9 ,janu>y4 ,we may />t at any mon? 9 ! ye> & we w f9d ! con/ellations giv5 = t mon? on or ne> ! m]idian at ! "t indicat$4 ,9 us+ ! *>ts or diagrams ( ! con/ellations1 we %\ld hold !m 9 an inv]t$ position ) ! top ( ! page t[>d ! nor? or else rememb] t ! left-h& side ( ! page is t[>d ! ea/ & ! "r-h& side ( ! page t[>d ! we/1 :i* is ! opposite ( ! arrangem5t = *>ts & maps ( ! e>?'s surface4 ,we %\ld also be> 9 m9d t ! con/ellations are all cont9ually %ift+ we/w>d = ! />s & ! moon & ! planets z well z ! sun rise daily 9 ! ea/ & set 9 ! we/4 ,?is is due to ! fact t ! e>? is turn+ 9 ! opposite direction on its axis1 t is f we/ to ea/4 ,9 tw5ty-f\r h\rs ! e>? turns completely ar\nd ) respect to ! heav5s or ?r\gh an angle ( #cfj1 s 9 "o h\r x turns ?r\gh an angle ( #cfj #bd or #ae4 ,z a result ! />s appe> to %ift we/w>d #ae e h\r4 ,?is is a di/ance ab\t equal 9 l5g? to ! h&le ( ! ,big ,dipp]1 :i* ,i am sure we all "k1 ev5 if we d n "k ano!r con/ellation 9 ! heav5s4 ,if1 !n1 we look at ! heav5s at a lat] h\r ?an t = :i* ! con/ellations are giv5 we w f9d !m f>!r we/w>d & if our "t ( obs]vation is e>li] 9 ! ev5+ ?an ! h\r m5tion$ we w f9d !m f>!r ea/w>d4 ,9 ! c\rse ( a ye> ! e>? makes "o trip ar\nd ! sun & faces 9 turn all p>ts ( ! heav5s4 ,t is1 x turns ?r\gh an angle ( #cfj ) respect to ! heav5s 9 a ye> or ?r\gh an angle ( #cfj #ab or #cj 9 "o mon?4 ,s z a result ( our revolution ar\nd ! sun1 :i* is also 9 a we/ to ea/ direction1 we see t all ! con/ellations are gradually %ift+ we/w>d at ! rate ( #cj a mon?4 ,x is = ?is reason t we see diff]5t con/ellations 9 diff]5t mon?s1 & x is because ( ! turn+ ( ! e>? on its axis t we see diff]5t con/ellations at diff]5t h\rs ( ! night4 ,if we %\ld sit up f sunset to sunrise & wat* ! />s rise 9 ! ea/1 pass ! m]idian & set 9 ! we/--z ! sun does by day--we %\ld see 9 turn ! same con/ellations t are to pass across ! heav5s 9 ! next six mon?s4 ,?is is because 9 twelve h\rs' "t we are c>ri$ ?r\gh ! same angle ) respect to ! heav5s by ! e>?'s rotation on its axis t we are 9 ! next six mon?s by ! motion ( ! e>? ar\nd ! sun4 ,let u suppose !n t ! "t we *oose = our obs]vation ( ! heav5s is ! la/ ( ! mon? :ile our *>ts are giv5 = ! fir/ ( ! mon?4 ,we mu/ look !n f>!r we/w>d = our con/ellations j z we mu/ look f>!r we/w>d if we *ose a lat] h\r 9 ! ev5+ = our obs]vations4 ,let u suppose t we *oose = our "t ( obs]vation half-pa/ eight 9 ! e>ly "p ( ,decemb]4 ,on or close to ! m]idian we w f9d ! con/ellations outl9$ 9 ! *>ts = ,decemb]4 ,to ! ea/ ( ! m]idian we w f9d ! con/ellations t are giv5 = ,janu>y & ,febru>y1 & to ! we/ ( ! m]idian ! con/ellations t are giv5 = ,novemb] & ,octob]4 ,s if we are p>ticul>ly ambiti\s or wi% to become acqua9t$ ) ! con/ellations m rapidly we may /udy at ! same "t ! con/ellations = ! prec$+ mon?s n[ we/ ( ! m]idian & ! con/ellations = ! foll[+ mon?s n[ ea/ ( ! m]idian z well z ! con/ellations = ! mon? :i* w be due nor? or s\? or directly ov]head z ! case may be4 ,if we 7 able to see ! />s by day z well z by night we w\ld obs]ve t z ! days g by ! sun is app>5tly mov+ cont9u\sly ea/w>d among c]ta9 con/ellations4 ,?is is a result ( ! e>?'s actual motion ar\nd ! sun 9 ! same direction4 ,! app>5t pa? ( ! sun among ! />s is call$ ! ecliptic & ! belt ( ! heav5s eight degrees wide on ei!r side ( ! ecliptic is call$ ! zodiac4 ,! con/ellations t lie )9 ?is belt ( ! zodiac are call$ zodiacal con/ellations4 ,! zodiac 0 divid$ by ! a/ronom] ,hipp>*us1 :o liv$ #afa-abf ,b4,c41 into twelve signs #cj wide1 & ! signs 7 nam$ = ! con/ellations ly+ at t "t )9 ea* ( ^! divisions4 ,^! zodiacal con/ellations are ,aries1 ,taurus1 ,gem9i1 ,canc]1 ,leo1 ,virgo1 ,libra1 ,scorpio1 ,sagitt>ius1 ,capricornus1 ,aqu>ius & ,pisces4 ,) ! exception ( ,libra1 ! ,scales1 all ( ^! con/ellations are nam$ = p or animals & ! ^w zodiac is d]iv$ f ! ,greek ^w mean+ ( animals4 ,ea* mon? ! sun moves ea/w>d #cj ?r\gh "o ( ^! zodiacal con/ellations4 ,9 ! days ( ,hipp>*us ! sun 0 9 ,aries at ! beg9n+ ( spr+1 at ! po9t :]e ! ecliptic crosses ! cele/ial equator--:i* lies directly above ! e>?'s equator4 ,?is po9t :]e ! ecliptic crosses ! equator 0 !n kn[n z ! ,fir/ ,po9t 9 ,aries4 ,! autumnal equ9ox 0 #ahj di/ant 9 ,aqu>ius & ! two po9ts 7 call$ ! equ9oxes because :5 ! sun is at ei!r equ9ox ! day & night are equal 9 l5g? all ov] ! _w4 ,n[ = c]ta9 reasons :i* we w n expla9 "h ! equ9octial po9ts are n fix$ 9 position b %ift gradually we/w>d at ! rate ( #a 9 #gj ye>s4 ,x is z if ! equ9oxes 7 advanc+ ea* ye> to meet ! sun on its return & _! we/w>d motion is !re=e call$ ,! ,precession ( ! ,equ9oxes4 ,s9ce ! days ( ,hipp>*us ?is motion has am\nt$ to ab\t #cj s t ! con/ellations no long] occupy ! signs ( ! zodiac t be> _! names4 ,! sun is n[ 9 ,pisces in/ead ( ,aries at ! beg9n+ ( spr+ & 9 ,virgo in/ead ( ,aqu>ius at ! beg9n+ ( fall4 ,n only ! sun b ! moon & planets z well move ?r\gh ! zodiacal con/ellations4 ,9 fact a limit = ! zodiac ( #h on ei!r side ( ! ecliptic 0 *os5 because x m>ks ! ext5t ( ! excursions ( ! moon & planets f ! ecliptic4 ,nei!r moon nor planets w be f\nd at a great] di/ance ?an #h on ei!r side ( ! ecliptic4 ,= conv5i5ce 9 det]m9+ ! positions ( ! heav5ly bodies ! a/ronom] assumes t !y lie ^u ! surface ( a cele/ial sph]e t has its c5t] at ! c5t] ( ! e>?4 ,! nor? pole ( ! cele/ial sph]e lies directly above ! nor? pole ( ! e>? & ! s\? pole ( ! cele/ial sph]e directly above ! s\? pole ( ! e>?4 ,! cele/ial equator is ! great circle ( ! cele/ial sph]e t lies midway betwe5 its nor? & s\? poles & directly above ! e>?'s equator4 ,! ecliptic is also a great circle ( ! cele/ial sph]e & cuts ! cele/ial equator at an angle ( #bc-a_/b 9 ! two po9ts #ahj ap>t kn[n z ! equ9octial po9ts1 ( :i* we h already spok54 ,! zodiacal con/ellations lie ne>ly ov]head )9 ! tropics & c be se5 to advantage all ov] ! _w except 9 pol> regions4 ,= e position ( ! e>?'s surface except at ! equator we h also our circumpol> con/ellations :i* are ! ones t nev] pass bel[ ! horizon = ! place ( obs]vation4 ,9 #dj ,n4 ,latitude ! ,big ,dipp] is a circumpol> con/ellation = x is above ! horizon at all h\rs ( ! day & night & all times ( ! ye>4 ,if our latitude is #dj ,n41 all />s )9 #dj ( ! nor? pole ( ! heav5s are circumpol> & nev] set1 :ile />s )9 #dj ( ! s\? pole ( ! heav5s nev] rise4 ,all o!r />s rise & set daily4 ,if we 7 at ! nor? pole all />s )9 #ij ( ! nor? pole ( ! heav5s w\ld be circumpol> & w\ld describe daily circuits ( ! pole p>allel to ! horizon rema9+ always above x4 ,if we 7 at ! equator all />s )9 z]o degrees ( ei!r pole w\ld be circumpol>1 t is no />s w\ld be circumpol>1 all />s ris+ & sett+ daily4 ,z a g5]al rule1 !n1 we may say t />s )9 an angul> di/ance ( ! ne>e/ pole ( ! heav5s equal to ! latitude nev] set & />s )9 an equal di/ance ( ! opposite pole nev] rise :ile all />s outside ( ^! limits rise & set daily4 ,! beg9n] :o attempts to make ! acqua9tance ( ! pr9cipal />s & con/ellations occasionally may f9d a bright /> 9 a con/ellation t is n not$ 9 ! diagrams4 ,9 ?is case he has probably happ5$ ^u "o ( ! bright planets4 ,x is n possible to include ! planets 9 our diagrams = ! reason t !y are n fix$ 9 position b app>5tly w&] among ! />s4 ,! "n planet is1 9 fact1 d]iv$ f a ,greek ^w mean+ w&]]4 ,! />s %9e by _! own light b ! planets %9e only by reflect$ light f ! sun4 ,( ! sev5 planets 9 ! sol> sy/em additional to our own planet e>?1 !re are two1 ,uranus & ,neptune t we ne$ n consid] = ,neptune is n visible )\t ! aid ( a telescope & ,uranus is fa9t] ?an any ( ! />s includ$ 9 our diagrams4 ,m]cury w nev] appe> except 9 ! morn+ or ev5+ twilight1 :5 none b ! v brighte/ />s are visible1 s9ce x nev] dep>ts f> f ! sun4 ,x w only be se5 "u c]ta9 favorable conditions1 & usually x w escape our notice altoge!r unless we "k exactly :]e to look = x al?\gh !re are b two or ?ree />s 9 ! heav5s t surpass x 9 brightness4 ,v5us1 we w probably nev] mi/ake = any /> 9 ! heav5s = x f> surpasses all />s 9 brightness4 ,x w always be se5 9 ! we/ aft] sunset or 9 ! ea/ be=e sunrise & x is nev] se5 m ?an ?ree h\rs be=e or aft] ! sun4 ,?is leaves u b ?ree planets1 ,jupit]1 ,saturn & ,m>s t we may mi/ake = bright />s4 ,!re is little *ance t ,jupit] w be ?us mi/ak5 = x also is f> bright] ?an all ( ! />s except ,sirius :i* diff]s greatly f ,jupit] 9 color4 ,sirius is a brilliant :ite & ,jupit] is a gold5 yell[4 ,! planets d n tw9kle z ! />s d & ?is is p>ticul>ly true ( ,jupit] :i* is rem>kable = ! quiet /ead9ess ( its yell[ light4 ,?is alone w\ld s]ve to id5tify x4 ,saturn is probably mi/ak5 = a /> (t5] ?an any ( ! o!r planets4 ,x moves s sl[ly among ! />s t we w\ld h to wat* x = a numb] ( successive ev5+s be=e we c\ld discov] t x is mov+ ) respect to ! />s4 ,saturn is yell[i% 9 color & we c probably be/ di/+ui% x by ! /ead9ess ( its light4 ,if we f9d 9 "o ( ! zodiacal gr\ps ( />s--= ! planets appe> among no o!r con/ellations--a bright yell[i% /> :]e no bright /> is indicat$ on ! diagram we may be reasonably c]ta9 t we h f\nd ! planet ,saturn4 ,m>s is ! only planet t is r$di% 9 color4 ,once 9 fifte5 or sev5te5 ye>s1 :5 x is p>ticul>ly ne> to ! e>?1 x surpasses ev5 ,jupit] 9 brightness1 b ord9>ily x appe>s no m brilliant ?an "o ( ! bright] />s4 ,!re are only two />s ) :i* we are likely to confuse ,m>s1--,aldeb>an & ,ant>es--:i* are v simil> to x 9 color1 &1 at times1 9 brightness4 ,moreov]1 bo? ( ^! />s are zodiacal />s & ,m>s frequ5tly passes ?r\gh ! con/ellations to :i* !y belong4 ,!re %\ld be no tr\ble ab\t id5tify+ ,aldeb>an & ,ant>es1 h[ev]1 f _! di/9ctive positions 9 ! diagrams s t any o!r r$di% /> appe>+ 9 any ( ! zodiacal gr\ps we may feel c]ta9 is ! planet ,m>s4 ,9 ! foll[+ diagrams ( ! con/ellations ! brighte/ & mo/ conspicu\s />s1 call$ fir/-magnitude />s1 are repres5t$ by :ite />s4 ,^! are ! />s we %\ld all be able to recognize & call by "n & 9 e in/ance ! "n ( a fir/-magnitude /> is giv5 on ! diagram4 ,all o!r />s are repres5t$ by circles1 & ! size ( ! circle is an indication ( ! brightness ( ! />4 ,/>s visible )\t ! aid ( a telescope are ref]r$ to usually z nak$-eye />s4 ,!y are class$ z fir/1 second1 ?ird1 f\r1 fif? or six? magnitude />s1 accord+ to _! relative brightness4 ,a /> ( ! fir/ magnitude is ab\t two & "o-half times bright] ?an a /> ( ! second magnitude1 :i* 9 turn is two & "o-half times bright] ?an a /> ( ! ?ird magnitude & s on4 ,a fir/-magnitude /> is1 !n1 "o hundr$ times bright] ?an a six? magnitude /> :i* is ! fa9te/ /> t c be se5 )\t ! aid ( ! telescope4 ,?is ratio betwe5 successive magnitudes cont9ues among ! telescopic />s4 ,a /> ( ! six? magnitude is "o hundr$ times bright] ?an a /> ( ! elev5? magnitude :i* 9 turn is "o hundr$ times bright] ?an a /> ( ! sixte5? magnitude4 ,! fa9te/ />s t c be se5 visually 9 ! greate/ telescopes are ( ! sev5te5? or eighte5? magnitude1 ?\gh />s two or ?ree magnitudes fa9t] c be photograph$4 ,! fa9te/ />s %[n 9 ! diagrams are fif?-magnitude />s & />s ( ?is magnitude z well z />s ( ! f\r? magnitude are only giv5 :5 ne$$ to fill out ! di/9ctive outl9es ( ! con/ellations :i* h be5 =m$ by connect+ ! pr9cipal />s 9 ea* gr\p by dott$ l9es4 ,all />s ( fir/1 second & ?ird magnitude are giv5 9 ! diagrams )\t exceptions z su* />s are visible to ev]yone on cle> nights4 ,! con/ellations giv5 9 ! foll[+ pages include practically all ( ! con/ellations t c be se5 9 #dj ,n4 ,latitude4 ,a diagram is giv5 = ea* con/ellation4 ,9 ?is latitude x is impossible to see ! con/ellations ( ! s\!rn hemisph]e t lie )9 #dj ( ! s\? pole ( ! heav5s4 ,a brief *apt] ) diagram treats ( ^! con/ellations t are invisible 9 mid-latitudes ( ! nor!rn hemisph]e4 ,,ii ,,janu>y ,"o ( ! mo/ easily recogniz$ con/ellations 9 ! heav5s is ,taurus1 ,! ,bull1 a zodiacal gr\p :i* lies j s\? ( ! z5i? 9 our latitudes 9 ! e>ly ev5+ h\rs ab\t ! fir/ ( ,janu>y4 ,taurus is di/+ui%$ by ! ,v-%ap$ gr\p ( ,! ,hyades1 :i* conta9s ! bright1 r$1 fir/-magnitude /> ,aldeb>an1 repres5t+ ! fi]y eye ( ! bull4 ,x also conta9s ! fam\s clu/] ( fa9t />s kn[n z ,! ,pleiades1 ly+ a %ort di/ance nor?we/ ( ,! ,hyades4 ,no gr\p ( />s is m univ]sally kn[n ?an ,! ,pleiades4 ,all tribes & nations ( ! _w1 f ! remote/ days ( record$ hi/ory up to ! pres5t "t1 h sung ! praises ( ,! ,pleiades4 ,!y 7 ,! ,_m ,little ,ones ( ! ,babylonians1 ,! ,sev5 ,si/]s ( ! ,greeks1 ,! ,sev5 ,bro!rs ( ! ,am]ican ,indians1 ,! ,h5 & ,*ick5s ( _m nations ( ,europe1 ,! ,little ,eyes ( ! ,s\? ,sea ,isl&]s4 ,!y 7 honor$ 9 ! religi\s c]emonies ( ! ,aztecs1 & ! savage tribes ( ,au/ralia danc$ 9 _! honor4 ,_m e>ly tribes ( m5 began _! ye> ) ,novemb]1 ! ,pleiad mon?2 & on ,novemb] #ag?1 :5 ,! ,pleiades cross$ ! m]idian at midnight1 x 0 said t no petition 0 ev] pres5t$ 9 va9 to ! k+s ( anci5t ,p]sia4 ,illu/ration3 ,,janu>y--,,taurus ,poets ( all ages h felt ! *>m ( ,! ,pleiades4 ,t5nyson gives ! foll[+ beautiful description ( ,! ,pleiades 9 ,locksley ,hall3 ,_m a night ,i saw ! ,pleiades1 ris+ ?r\gh ! mell[ %ade1 ,glitt] l a sw>m ( fireflies tangl$ 9 a silv] braid4 ,a well-kn[n a/ronom]1 n s _m ye>s ago1 also felt ! my/]i\s *>m ( ,! ,pleiades & s]i\sly express$ ! belief t ,alcyone1 ! brighte/ /> ( ,! ,pleiades1 0 a c5tral sun ab\t :i* all o!r suns 7 mov+4 ,b we "k t !re is no f\ndation :atev] = su* a belief4 ,a fairly good eye1 :5 ! night is cle> & d>k1 w make out six />s 9 ?is gr\p arrang$ 9 ! =m ( a small dipp]4 ,a sev5? /> lies close to ! /> at ! end ( ! h&le & is m difficult to f9d4 ,x is call$ ,pleione1 & is ref]r$ to 9 _m leg5ds z ! lo/ ,pleiad4 ,p]sons gift$ ) exceptionally f9e eyesight h made out z _m z elev5 />s 9 ! gr\p2 & ) ! aid ( an ord9>y op]a-glass1 anyone c see fully "o hundr$ />s 9 ?is clu/]4 ,a/ronom]s h f\nd t ,! ,pleiades clu/] conta9s at lea/ two hundr$ & fifty />s1 all drift+ sl[ly 9 ! same g5]al direction ?r\gh space1 & t ! entire gr\p is envelop$ 9 a fi]y1 nebul\s mi/ :i* is mo/ d5se ar\nd ! brighte/ />s4 ,x is n kn[n :e!r ! />s are be+ =m$ f ! nebula or :e!r ! nebula is be+ puff$ (f f ! />s4 ,! brighte/ />1 ,alcyone1 is at lea/ two hundr$ times m brilliant ?an our own sun1 & all ( ! bright] />s 9 ! gr\p surpass ! sun _m times 9 brightness4 ,x is believ$ t ?is clu/] is s l>ge t light takes _m ye>s to cross f "o end ( x to ! o!r1 & t x is s f> f ! e>? t its light takes ov] ?ree c5turies to rea* u1 travel+ at ! rate ( #ahf1jjj miles a second4 ,! ,hyades is a gr\p ( />s sc>cely less fam\s ?an ,! ,pleiades1 & ! />s 9 ! gr\p also =m a mov+ clu/] ( enorm\s ext5t at a di/ance ( #adj light-ye>s f ! e>?4 ,among ! anci5ts1 ,! ,hyades 7 call$ ! ra9-/>s1 & ! ^w ,hyades is suppos$ to come f ! ,greek ^w = ra94 ,among ! _m sup]/itions ( ! pa/ 0 ! belief t ! ris+ or sett+ ( a gr\p ( />s ) ! sun _h "s special influ5ce ov] human affairs4 ,s9ce ,! ,hyades set j aft] ! sun 9 ! %[]y spr+time & j be=e sunrise 9 ! /ormy days ( late fall1 !y 7 always associat$ ) ra94 ,9 ,t5nyson's ,ulysses we read3 ,?r\gh scudd+ drifts ! ra9y ,hyades ,vex'd ! dim sea4 ,! ,hyades outl9e ! =ehead ( ,taurus1 :ile two bright />s "s di/ance to ! nor!a/ ( ! ,v =m ! tips ( ! horns4 ,only ! head & =equ>t]s ( ! bull are %[n 9 ! />-atlases t give ! my?ological gr\ps1 =1 accord+ to "o leg5d1 he is swimm+ ?r\gh ! sea & ! re/ ( 8 body is subm]g$4 ,accord+ to ano!r leg5d1 ,taurus is *>g+ d[n ^u ,orion1 ,! ,w>rior1 repres5t$ by ! magnific5t con/ellation j to ! s\!a/ ( ,taurus1 ( :i* we %all h m to say next mon?4 ,aldeb>an is ! ,arabic ^w = ,! ,h9dmo/1 & ! /> is s call$ because x foll[s ,! ,pleiades across ! sky4 ,x is "o ( ! mo/ beautiful ( all ! _m brilliant />s visible at ?is "t & we might pr(it by foll[+ ! advice ( ,mrs4 ,sig\rney 9 ,! ,/>s3 ,g =? at night ,& talk ) ,aldeb>an1 :]e he flames ,9 ! cold =ehead ( ! w9try sky4 ,next to ,aldeb>an 9 ! ,v is ! int]e/+ d\ble /> ,!ta1 :i* we c see z two di/9ct />s )\t a telescope4 ,directly s\? ( ,taurus is ,eridanus1 sometimes call$ ,fluvius ,eridanus1 or ,! ,riv] ,eridanus4 ,/>t+ a little to ! s\!a/ ( ,taurus1 close to ! brilliant blue-:ite /> ,rigel 9 ,orion1 x runs to ! we/w>d = a consid]able di/ance 9 a long curv+ l9e ( r fa9t />s1 b5ds %>ply s\?w>d = a %ort di/ance1 !n curves backw>d t[>d ! ea/ once m1 &1 aft] runn+ = "s di/ance1 makes ano!r %>p curve to ! s\?we/ & disappe>s bel[ ! s\!rn horizon4 ,its c\rse is cont9u$ f> into ! s\!rn hemisph]e4 ,its brighte/ />1 ,a*]n>1 is a /> ( ! fir/ magnitude1 b x lies bel[ ! horizon 9 our latitudes4 ,illu/ration3 ,,janu>y--,,eridanus ,eridanus conta9s no /> ( p>ticul> int]e/ to u4 ,mo/ ( ! num]\s />s t m>k its c\rse are ( ! f\r? & fif? magnitude4 ,x conta9s b two />s ( ! ?ird magnitude1 "o at ! beg9n+ ( its c\rse & "o close to ! s\?we/]n horizon4 ,! beautiful con/ellation ( ,p]seus lies j to ! nor? ( ,taurus & %\ld rightfully be consid]$ among ! con/ellations ly+ ne>e/ to ! m]idian 9 ,janu>y1 b we give ?is con/ellation among ! /> gr\ps = ,decemb] because ( its close association ) ! ne>by con/ellations ,&rom$a & ,pegasus 9 leg5d & /ory4 ,,iii ,,febru>y ,across ! m]idian1 due s\?1 betwe5 eight & n9e o'clock 9 ! ev5+ 9 ! e>ly "p ( ,febru>y1 lies ,orion1 ,! ,w>rior1 g5]ally consid]$ to be ! f9e/ con/ellation 9 ! heav5s4 ,orion is directly ov]head at ! equator1 & s is se5 to advantage f all p>ts ( ! _w except ! extreme nor!rn & s\!rn pol> regions4 ,a gr\p ( ?ree fa9t />s outl9es ! head ( ,orion4 ,8 "r %\ld] is m>k$ by ! deep-r$1 fir/-magnitude /> ,betelgeuze 7mean+ armpit71 & 8 left %\ld] by ! bright :ite /> ,bellatrix1 ,! ,amazon4 ,orion /&s fac+ ,taurus1 ,! ,bull1 & br&i%es 9 8 "r h& a club1 outl9$ by a numb] ( fa9t />s ext5d+ f ,betelgeuze t[>d ! nor!a/4 ,! top ( ! club lies ne> ! tips ( ! horns ( ,taurus4 ,9 8 left h& he holds up a lion's sk91 :i* we c trace 9 ano!r curv+ l9e ( fa9t />s to ! we/ & nor?we/ ( ,bellatrix4 ,! brilliant1 blue-:ite1 fir/-magnitude /> ,rigel lies 9 ! left foot1 & ! second-magnitude /> ,saiph1 a little to ! ea/ ( ,rigel1 is 9 ! "r knee4 ,?ree ev5ly spac$ />s ly+ 9 a /raight l9e t is exactly ?ree degrees 9 l5g? =m ! ,belt ( ,orion1 & f ! ,belt hangs ! ,sword ( ,orion1 outl9$ by ?ree fa9t />s4 ,! c5tral /> 9 ! ,sword appe>s some:at blurr$ & is ! multiple /> ,!ta1 9 ! mid/ ( ! great ,orion nebula1 ! f9e/ object ( its k9d 9 ! heav5s4 ,entangl$ 9 ! me%es ( ?is gl[+ nebula are a numb] ( brilliant suns1 appe>+ to u z fa9t />s because ( _! great di/ance4 ,! /> ,!ta1 9 ! he>t ( ! nebula1 is se5 ) a p[]ful telescope to consi/ ( six />s2 t is1 x is a sextuple />4 ,ev5 ) a small telescope1 f\r ( ^! />s c readily be se51 arrang$ 9 ! =m ( a small trapezium4 ,! l[e/ /> 9 ! ,sword is a triple />1 & ! entire con/ellation ab\nds 9 d\ble1 triple1 & multiple />s4 ,f ! c5tral portion ( ! nebula ext5d _m bran*es & /ream]s ( nebul\s light1 & x is kn[n t ! entire con/ellation ( ,orion is enwrapp$ 9 ! folds ( ?is nebulosity1 :i* =ms a gl[+1 :irl+ mass ( fi]y gases 9 rapid rotation4 ,?is con/ellation is rem>kable = ! fact t all ( its bright] />s1 ) ! exception ( ! deep-r$ ,betelgeuze1 =m "o enorm\s1 connect$ gr\p ( />s4 ,!y are all m or less associat$ ) ! great nebula & its bran*es1 & are all extremely hot1 :ite or blui%-:ite />s1 kn[n z helium />s1 because ! gas helium is s conspicu\s 9 _! atmosph]es4 ,! ,orion />s are ! hotte/ & brighte/ ( all ! />s4 ,blaz+ ,rigel1 ,bellatrix1 & ,saiph1 m>k+ ?ree corn]s ( ! great quadrilat]al1 ( :i* ,betelgeuze m>ks ! f\r? corn]1 are all brilliant helium />s4 ,s are ! ?ree />s 9 ! ,belt & ! fa9t] />s 9 ! ,sword & ! great nebula4 ,illu/ration3 ,,febru>y--,,orion ,x has be5 e/imat$ t ! great ,orion gr\p ( />s is ov] six hundr$ light-ye>s f ! e>?1 or ab\t =ty million times m di/ant ?an ! sun4 ,= m ?an six c5turies ! rays ( light t n[ ent] our eyes f ^! />s h be5 travel+ ?r\gh space ) ! spe$ ( lightn+4 ,s we see ,orion n z x exi/s today1 b z x 0 six c5turies ago4 ,! ext5t ( ! ,orion gr\p ( />s is also inconceivably great4 ,ev5 ! c5tral "p ( ! great nebula1 :i* appe>s to our unaid$ eyes only z a some:at fuzzy />1 w\ld ext5d f "h to ! ne>e/ /> & beyond1 :ile our entire sol> sy/em w\ld be ! m]e/ speck 9 its mid/4 ,betelgeuze1 ! r$ /> t m>ks ! "r %\ld] ( ,orion1 is1 z we h said1 n a memb] ( ! ,orion gr\p4 ,x has be5 e/imat$ t x is ab\t two hundr$ light-ye>s f ! e>?1 or only ab\t "o-?ird z f> away z ! o!r />s ( ! con/ellation4 ,betelgeuze v rec5tly has attract$ univ]sal att5tion1 & w probably be consid]$ an object ( hi/oric int]e/ 9 ! future1 because x is ! fir/ /> to h its diamet] measur$ ) ! new ,mi*elson int]f]omet]1 :i* is n[ be+ us$ s successfully to measure ! diamet]s ( ! l>ge/ />s4 ,! truly s5sational discov]y has be5 made t ,betelgeuze is a sup]giant ( ! univ]se1 ) a diamet] ( ab\t #bge1jjj1jjj miles4 ,our own sun1 :i* is kn[n z a dw>f />1 has a diamet] ( #hfd1jjj miles4 ,t is1 ,betelgeuze w\ld make ab\t ?irty million suns ! size ( our own4 ,if plac$ at ! c5t] ( ! sol> sy/em1 x w\ld fill all ( ! space )9 ! orbit ( ,m>s2 & ! planets ,m]cury1 ,v5us1 & ! ,e>? w\ld lie f> b5ea? its surface4 ,measurem5ts ( ! diamet]s ( o!r giant />s :i* are n[ be+ made ) ! int]f]omet] give results q z />tl+ z h be5 obta9$ 9 ! case ( ,betelgeuze2 & x has be5 f\nd t sev]al ( ^! />s may ev5 exce$ ,betelgeuze 9 size4 ,su* a /> is ,ant>es1 ! fi]y-r$ /> 9 ! he>t ( ,scorpio1 :i* is su* a conspicu\s object 9 ! summ] ev5+ skies4 ,all ^! huge />s are deep r$ 9 color1 & "s ( !m v>y irregul>ly 9 brightness4 ,betelgeuze is "o ( ! />s t *anges 9 brightness 9 a peculi> mann] f "t to "t4 ,:5 %9+ ) its greate/ brilliancy x is a bright] object ?an ! ne>by /> ,aldeb>an1 9 ,taurus2 b a few mon?s or a ye> lat] x may lose s mu* ( its light z to be decid$ly inf]ior to ,aldeb>an4 ,we may note = ourselves ?is rem>kable *ange 9 ! brightness ( ,betelgeuze by comp>+ ! two />s f "t to "t4 ,directly s\? ( ,orion lies ! small con/ellation ( ,lepus1 ,! ,h>e1 :i* is made up ( ?ird-magnitude & f\r?-magnitude />s4 ,! f\r bright] />s are arrang$ 9 ! =m ( a small1 b di/9ct1 quadrilat]al1 or f\r-sid$ figure1 :i* may be easily se5 9 our latitudes4 ,! small con/ellation ( ,columba1 ,! ,dove1 :i* lies j s\? ( ,lepus1 is s close to ! horizon t x c n be se5 to advantage 9 ! mid-latitudes ( ! nor!rn hemisph]e4 ,nei!r ,lepus nor ,columba conta9 any object ( unusual int]e/4 ,illu/ration3 ,,febru>y--,,auriga ,due nor? ( ,orion1 & ly+ 9 ! z5i? at ?is "t1 is ,auriga1 ,! ,*>iote]1 repres5t$1 /range to say1 ) ,capella1 a goat1 9 8 arms4 ,! beautiful fir/-magnitude /> ,capella1 gold5-yell[ 9 color1 s]ves u 9 id5tify+ ! con/ellation4 ,close at h& are ,! ,kids1 repres5t$ by a gr\p ( ?ree fa9t />s4 ,capella is "o ( ! mo/ brilliant />s ( ! nor!rn hemisph]e4 ,x is almo/ exactly equal 9 brightness to ,arcturus & ,vega1 />s conspicu\s 9 ! summ] mon?s1 & x is a %ade bright] ?an magnific5t blue-:ite ,rigel 9 ,orion4 ,capella is ab\t fifty light-ye>s di/ant f ! e>? & is fully two hundr$ times m brilliant ?an our own sun4 ,at ! di/ance ( ,capella1 ! sun w\ld appe> to be consid]ably fa9t] ?an any "o ( ! ?ree />s 9 ! ne>by gr\p ( ,! ,kids4 ,capella is att5d$ by a companion /> s close to its brilliant rul] t x c n be se5 z a sep>ate /> save ) ! aid ( ! mo/ p[]ful telescopes4 ,its di/ance f ,capella has be5 v accurately measur$1 h[ev]1 by means ( ! int]f]omet]1 :i* is giv+ u ! measurem5ts ( ! diamet]s ( ! giant />s4 ,x is kn[n t ?is companion sun is clos] to ,capella ?an our planet e>? is to ! sun4 ,at no "t ( ! ye> %all we f9d ne> ! m]idian s _m brilliant & beautiful />s z appe> 9 ! mon? ( ,febru>y at ?is "t 9 ! ev5+4 ,9 addition to ,capella1 :i* is "o ( ! ?ree mo/ brilliant />s 9 ! nor!rn hemisph]e ( ! heav5s1 we h1 9 ,orion alone1 two />s ( ! fir/ magnitude1 ,betelgeuze & ,rigel1 & five />s ( ! second magnitude1 ,bellatrix & ,saiph & ! ?ree />s 9 ! ,belt4 ,9 addition1 we h n f> di/ant 9 ! we/]n sky1 fi]y ,aldeb>an 9 ,taurus1 & close on ! heel ( ,orion 9 ! ea/1 ,sirius1 ! brighte/ /> 9 ! heav5s1 9 ! con/ellation ( ,canis ,major1 ,! ,great] ,dog1 z well z ! fir/-magnitude /> ,procyon 9 ,canis ,m9or1 ,! ,less] ,dog4 ,( ^! two gr\ps we %all h m to say "u ! con/ellations = ,m>*4 ,,iv ,,m>* ,to ! s\!a/ ( ,orion & almo/ due s\? at eight o'clock 9 ! ev5+ on ! fir/ ( ,m>* lies ! con/ellation ( ,canis ,major1 ,! ,great] ,dog1 conta9+ ,sirius1 ! ,dog-/>1 :i* f> surpasses all o!r />s 9 ! heav5s 9 brilliancy4 ,sirius lies almo/ 9 l9e ) ! ?ree />s t =m ! ,belt ( ,orion4 ,we %all n h ! slighte/ difficulty 9 recogniz+ x1 ow+ to its surpass+ brilliancy z well z to ! fact t x foll[s s closely ^u ! heels ( ,orion4 ,sirius is ! ,greek = scor*+ or sp>kl+1 & ! anci5ts attribut$ ! scor*+ heat ( summ] to ! fact t ,sirius !n rose ) ! sun4 ,! torrid days ( midsumm] !y call$ ! dog-days = ?is reason1 & we h reta9$ ! expression to ! pres5t "t4 ,s9ce ,sirius 0 always associat$ ) ! discom=ts ( ! torrid season1 x did n h an enviable reputation among ! ,greeks4 ,we f9d 9 ,pope's translation ( ! ,iliad ?is ref]5ce to ,sirius3 ,t]rific glory6 = 8 burn+ brea? ,ta9ts ! r$ air ) fev]1 plagues1 & dea?4 ,9 ,egypt1 h[ev]1 _m temples 7 d$icat$ to ! wor%ip ( ,sirius1 = ! reason t "s five ?\s& ye>s ago x rose ) ! sun at ! "t ( ! summ] sol/ice1 :i* m>ks ! beg9n+ ( summ]1 & h]ald$ ! approa*+ inundation ( ! ,nile1 :i* 0 an occasion = great rejoic+ among ! ,egyptians4 ,x 01 !re=e1 call$ ! ,nile ,/> & reg>d$ by !m ) ! greate/ rev]5ce4 ,sirius is an int5sely :ite hydrog5 />2 b ow+ to its great brilliancy & to ! fact t x does n atta9 a great height above ! horizon 9 our latitudes1 its rays are greatly refract$ or brok5 up by ! atmosph]e1 :i* is mo/ d5se ne> ! horizon1 & z a result1 x tw9kles or sc9tillates m noticeably ?an o!r />s & fla%es ! spectrum colors--*iefly r$ & gre5--l a true diamond 9 ! sky--a magnific5t object 9 ! telescope4 ,sirius is "o ( our ne>e/ neighbors among ! />s4 ,only two />s are kn[n to be ne>] to ! sol> sy/em4 ,yet its light takes ab\t eight & a half ye>s to fla% ) lightn+ spe$ across ! great int]v5+ *asm4 ,x is att5d$ also by a v fa9t /> t is s lo/ 9 ! rays ( its brilliant companion t x c only be f\nd ) ! aid ( a p[]ful telescope4 ,! two />s are sep>at$ by a di/ance ( #a1hjj1jjj1jjj miles2 t is !y are ab\t z f> ap>t z ,neptune & ! sun4 ,!y sw+ sl[ly & maje/ically ab\t a common c5t]1 call$ _! c5t] ( gravity1 9 a p]iod ( ab\t =ty-n9e ye>s4 ,s fa9t is ! companion ( ,sirius t x is e/imat$ t tw5ty ?\s& su* />s w\ld be ne$$ to give =? z mu* light z ,sirius4 ,! two />s toge!r1 ,sirius & its companion1 give =? tw5ty-six times z mu* light z our own sun4 ,!y weigh only ab\t ?ree times z mu*1 h[ev]4 ,! companion ( ,sirius1 9 spite ( its extreme fa9tness1 weighs fully half z mu* z ! brilliant />4 ,illu/ration3 ,,m>*--,,canis ,,major ,!re are a numb] ( bright />s 9 ! con/ellation ( ,canis ,major4 ,a fairly bright /> a little to ! we/ ( ,sirius m>ks ! uplift$ paw ( ! dog1 & to ! s\!a/1 9 ! tail & h9d qu>t]s1 are sev]al conspicu\s />s ( ! second magnitude4 ,a little to ! ea/ & mu* f>!r to ! nor?1 we f9d ,canis ,m9or1 ,! ,less] ,dog1 conta9+ ! beautiful fir/-magnitude /> ,procyon1 ,precursor ( ! ,dog--t is1 ( ,sirius4 ,s9ce ,procyon is s mu* f>!r nor? ?an ,sirius & v little to ! ea/1 we see its brilliant rays 9 ! ea/]n sky "s "t be=e ,sirius appe>s above ! s\!a/]n horizon1 h5ce its "n4 ,long aft] ,sirius has disappe>$ f view b5ea? ! we/]n horizon 9 ! late spr+1 ,procyon may /ill be se5 l[ 9 ! we/]n sky4 ,procyon1 also is "o ( our ne>] neighbors among ! />s1 be+ only ab\t t5 light-ye>s di/ant f ! sol> sy/em4 ,l ,sirius1 x is a d\ble /> ) a mu* fa9t] companion1 t by its attraction sways ! motion ( ,procyon to su* an ext5t t we %\ld "k ( its exi/5ce1 ev5 if x 7 n visible1 by ! di/urbances x produces 9 ! motion ( ,procyon4 ,! p]iod ( revolution ( ,procyon & its companion ab\t a common c5t] is ab\t =ty ye>s1 & ! two />s comb9$ weigh ab\t a ?ird m ?an our own sun & give =? six times z mu* light4 ,canis ,m9or conta9s only "o o!r bright />1 ,beta1 a %ort di/ance to ! nor?we/ ( ,procyon4 ,orig9ally1 ! "n ,procyon 0 giv5 to ! entire con/ellation1 b x 0 lat] us$ only ) ref]5ce to ! "o />4 ,procyon1 ,sirius1 & ,betelgeuze 9 ,orion =m a huge equal-sid$ triangle t lies across ! m]idian at ?is "t & is a mo/ conspicu\s configuration 9 ! ev5+ sky4 ,illu/ration3 ,,m>*--,,gem9i ,,& ,,canis ,,m9or ,directly s\? ( ! z5i? we f9d ,gem9i1 ,! ,tw9s1 "o ( ! zodiacal con/ellations4 ,x is 9 ,gem9i t ! sun is to be f\nd at ! beg9n+ ( summ]4 ,! two bright />s ,ca/or & ,pollux m>k ! heads ( ! tw9s1 & ! two />s 9 ! opposite corn]s ( ! f\r-sid$ figure %[n 9 ! *>t m>k _! feet4 ,ca/or & ,pollux1 accord+ to ! leg5d1 7 ! tw9 bro!rs ( ,hel5 ( ,troy :o w5t on ! ,argonautic exp$ition4 ,:5 a /orm ov]took ! vessel on its return voyage1 ,orpheus invok$ ! aid ( ,apollo1 :o caus$ two />s to %9e above ! heads ( ! tw9s1 & ! /orm imm$iately ceas$4 ,x 0 = ?is reason t ,ca/or & ,pollux became ! special deities ( seam51 & x 0 cu/om>y to place _! effigies ^u ! pr[s ( vessels4 ,! ,by ,jim9i6 ( today is b a corruption ( ! ,by ,gem9i6 he>d s frequ5tly among ! sailors ( ! anci5t _w4 ,! a/ronomical "n = ,ca/or1 ! fa9t] />1 is ,alpha ,gem9orum1 mean+ ,alpha ( ,gem9i4 ,z x 0 cu/om>y to call ! brighte/ /> 9 a con/ellation by ! fir/ lett] 9 ! ,greek alphabet1 x is believ$ t ,ca/or has decreas$ consid]ably 9 brightness s9ce ! days ( ! anci5ts1 = x is n[ decid$ly inf]ior to ,pollux 9 brightness1 :i* is call$ ,beta ,gem9orum4 ,( ! two />s1 ,ca/or is ! m int]e/+ because x is a d\ble /> t is readily sep>at$ into two />s ) ! aid ( a small telescope4 ,! two pr9cipal />s are kn[n to be1 9 turn1 extremely close d\ble />s revolv+ almo/ 9 contact 9 p]iods ( a few days4 ,:]e we see b "o /> ) ! unaid$ eye1 !re is1 !n a sy/em ( f\r suns1 ! two close pairs revolv+ sl[ly ab\t a common c5t] ( gravity 9 a p]iod ( sev]al c5turies & at a great di/ance ap>t4 ,! /> ,pollux1 :i* we c easily di/+ui% by its sup]ior brightness1 is ! m s\!rly ( ! tw9 />s & lies due nor? ( ,procyon & ab\t z f> f ,procyon z ,procyon is f ,sirius4 ,! appe>ance ( ,gem9i on ! m]idian 9 ! e>ly ev5+ & ( ! huge triangle1 ) its corn]s m>k$ by ! brilliants1 ,procyon1 ,sirius1 & ,betelgeuze1 due s\?1 ) ,great ,orion slop+ sl[ly to ! we/1 is z truly a sign ( approa*+ spr+ z ! gradual l5g!n+ ( ! days1 ! appe>ance ( crocuses & daffodils1 & ! fir/ rob94 ,x is only a few weeks lat]--z pictur$ by ,t5nyson 9 ,maud-- ,:5 ! face ( ! night is fair on ! dewy d[ns1 ,& ! %9+ daffodil dies1 & ! ,*>iote] ,& />ry ,gem9i hang l glori\s cr[ns ,ov] ,orion's grave l[ d[n 9 ! we/4 ,v ,,april ,9 ! e>ly ev5+ h\rs ( ,april ! we/]n sky is /ill adorn$ ) ! brilliant jewels ) :i* we became famili> on ! cle> fro/y ev5+s ( w9t]4 ,orion is n[ s9k+ fa/ to 8 re/ b5ea? ! we/]n horizon4 ,beautiful1 gold5 ,capella 9 ,auriga gl[s 9 ! nor?we/4 ,sirius sp>kles & sc9tillates1 a magnific5t diamond ( ! sky1 j above ! s\?we/]n horizon1 :ile ,procyon 9 ,canis ,m9or1 ,! ,less] ,dog1 & ,ca/or & ,pollux1 ,! ,tw9s1 9 ! con/ellation ( ,gem9i1 are /ill high 9 ! we/]n "p ( ! heav5s4 ,9 ! nor!a/ & ea/ may be se5 ! con/ellations t w be close to ! m]idian at ?is "t next mon?4 ,ursa ,major1 ,! ,great] ,be>1 ) its famili> ,big ,dipp]1 is n[ 9 a favorable position = obs]vation4 ,! ,sickle 9 ,leo is high 9 ! ea/]n sky1 & ,spica1 ! brilliant :ite diamond ( ! ev5+ skies ( spr+1 is l[ 9 ! s\!a/ 9 ,virgo4 ,ne> ! m]idian ?is mon? we f9d betwe5 ,auriga & ,ursa ,major1 & ea/ ( ,gem9i1 ! inconspicu\s con/ellation ( ,lynx1 :i* conta9s n a s+le bright /> & is a mod]n con/ellation devis$ simply to fill ! o!rwise vacant space 9 circumpol> regions betwe5 ,ursa ,major & ,auriga4 ,illu/ration3 ,,april--,,canc] ,j s\? ( ! z5i? at ?is "t1 & ly+ betwe5 ,gem9i & ,leo1 is ,canc]1 ,! ,crab1 ! mo/ inconspicu\s ( all ! zodiacal con/ellations4 ,!re are no bright />s 9 ?is gr\p1 & !re is also no?+ di/9ctive ab\t ! gr\p+ ( its fa9t />s1 ?\gh we c readily f9d x1 f its position betwe5 ! two neighbor+ con/ellations ( ,gem9i & ,leo by ref]5ce to ! *>t4 ,9 ! position indicat$ !re we w see on cle> ev5+s a fa9t1 nebul\s cl\d ( light1 :i* is kn[n z ,praesepe1 ,! ,beehive1 or z ,! ,mang]1 ! two fa9t />s flank+ x on ei!r side be+ call$ ,aselli1 ,! ,asses4 ,?is fa9t cl\d c be easily resolv$ by an op]a-glass into a co>se clu/] ( />s t lie j beyond ! range ( ! unaid$ human vision4 ,to ! anci5ts1 ,praesepe s]v$ z an indicator ( wea!r conditions1 & ,aratus1 an anci5t a/ronom]1 wrote ( ?is clu/]3 ,a murky mang]1 ) bo? />s ,%9+ unalt]$1 is a sign ( ra94 ,if :ile ! nor!rn ass is dimm$ ,by vapor\s %r\d1 he ( ! s\? gleam radiant1 ,expect a s\? w9d2 ! vapor\s %r\d & radiance ,ex*ang+ />s1 h>b+] ,boreas4 ,?is 0 n entirely a matt] ( sup]/ition1 z we might possibly imag9e1 = ! dimness ( ! clu/] is simply an indication t vapor is ga!r+ & cond5s+ 9 ! atmosph]e1 j z a r+ ar\nd ! moon is an indication ( ! same ga!r+ & cond5sation ( vapor t prec$es a /orm4 ,"s c5turies ago ! sun rea*$ its greate/ di/ance nor? ( ! equator--:i* occurs ea* ye> at ! beg9n+ ( summ]--at ! "t :5 x 0 pass+ ?r\gh ! con/ellation ( ,canc]4 ,our tropic ( ,canc]1 :i* m>ks ! nor!rn limit ( ! torrid zone1 receiv$ its "n f ?is fact4 ,at ! "t :5 ! sun rea*es ! po9t f>!/ nor?1 its height above ! horizon *anges v little f day to day1 & = a %ort "t x appe>s to be sl[ly crawl+ sideways ?r\gh ! heav5s1 z a crab walks1 & = ?is reason1 possibly1 ! con/ellation 0 call$ ,canc]1 ,! ,crab4 ,at ! pres5t "t ! ,precession ( ! ,equ9oxes1 or we/w>d %ift+ ( ! v]nal equ9ox--! po9t :]e ! sun crosses ! equator go+ nor? 9 ! spr+--br+s ! sun1 :5 x is f>!/ nor?1 9 ,gem9i in/ead ( 9 ,canc]4 ,at ! pres5t "t1 !n x w\ld be m accurate to speak ( ! tropic ( ,gem9i1 ?\gh ?is 9 turn w\ld be inaccurate aft] a lapse ( c5turies1 z ! sun pass$ into ano!r con/ellation at ! beg9n+ ( summ]4 ,! tropic ( ,capricorn1 :i* m>ks ! f>!/ s\!rn excursions ( ! sun 9 its ye>ly circuit ( ! heav5s1 %\ld also m appropriately be call$ ! tropic ( ,sagitt>ius1 z ! sun is n[ 9 ,sagitt>ius in/ead ( ,capricornus at ! "t :5 x is f>!/ s\?1 ?\gh ! po9t is sl[ly %ift+ we/w>d into ,scorpio4 ,my?ology tells u t ,canc] 0 s5t by ,juno to di/ract ,h]cules by p9*+ 8 toes :ile he 0 cont5d+ ) ! _m-head$ s]p5t 9 ! ,l]nean swamp4 ,h]cules1 ! leg5d says1 cru%$ ! crab ) a s+le bl[1 & ,juno by way ( rew>d plac$ x 9 ! heav5s4 ,9 ,canc]1 accord+ to ! belief ( ! ,*aldeans1 0 locat$ ! gate ( m51 by :i* s\ls desc5d$ into human bodies1 :ile 9 ,capricornus 0 ! gate ( ! gods1 ?r\gh :i* ! fre$ s\ls ( m5 return$ to heav54 ,illu/ration3 ,,april--,,hydra ,hydra1 ! _m-head$ s]p5t ) :i* ,h]cules cont5d$1 is repres5t$ by a con/ellation ( great l5g?4 ,x ext5ds f a po9t j s\? ( ,canc]1 :]e a gr\p ( fa9t />s m>ks ! heads1 to ! s\? & s\!a/ 9 a long l9e ( fa9t />s4 ,x passes 9 its c\rse j s\? ( ,crat] & ,corvus1 ! two small />-gr\ps bel[ ,leo 7see con/ellations = ,may71 :i* are sometimes call$ its rid]s1 & x also /ret*es bel[ ! entire l5g? ( ! long1 /raggl+ con/ellation ( ,virgo4 ,at ?is "t we c trace x only to ! po9t :]e x disappe>s bel[ ! horizon 9 ! s\!a/4 ,x conta9s b "o bright />1 ,alph>d1 or ,cor ,hydrae z x is also call$1 /&+ q alone & almo/ due s\? at ?is "t4 ,hydra1 z well z ,lynx & ,canc]1 conta9s no notewor?y or rem>kable object & consi/s *iefly ( fa9t />s4 ,alph>d is1 9 fact1 ! only bright /> t we h 9 ! con/ellations = ?is mon?4 ,x *ances t ^! ?ree inconspicu\s />-gr\ps1 ,lynx1 ,crat]1 & ,hydra1 lie ne>e/ to ! m]idian at ?is "t1 sep>at+ ! brilliant gr\ps ( w9t] f ^? ( ! summ] mon?s4 ,illu/ration3 ,,april--,,lynx ,,vi ,,may ,ursa ,major1 ! ,great ,be>1 & ,ursa ,m9or1 ! ,less] ,be>1 or1 z !y are m famili>ly call$1 ! ,big ,dipp] & ! ,little ,dipp]1 are ! be/ kn[n ( all ! con/ellations visible 9 nor!rn latitudes4 ,!y are call$ circumpol> con/ellations1 :i* means ar\nd ! pole4 ,= ^? :o live nor? ( #dj ,n4 ,lat4 !y nev] set1 b c be se5 at all h\rs ( ! night & at all times ( ! ye>4 ,9 fall & w9t] ev5+s ,ursa ,major lies bel[ ! pole & ne> ! horizon1 & s is usually hidd5 m or less f view by trees or build+s4 ,x is dur+ ! e>ly ev5+ h\rs ( late spr+ & summ] t ?is con/ellation is se5 to ! be/ advantage high 9 ! sky above ! pole4 ,if "o looks due nor? at ! "t m5tion$1 x w be impossible to miss ei!r ( ^! con/ellations4 ,to complete ! outl9e ( ! ,great ,be>1 x is necess>y to include fa9t />s to ! ea/1 :i* =m ! head ( ! ,be>1 & o!r fa9t />s to ! s\?1 :i* =m ! feet1 b ^! are all inconspicu\s & ( little g5]al int]e/4 ,! two />s 9 ! b[l ( ! ,big ,dipp] ?r\gh :i* an arr[ is drawn 9 ! *>t1 are call$ ! ,po9t]s1 because an imag9>y l9e drawn ?r\gh ^! two />s & cont9u$ a di/ance ab\t equal to ! l5g? ( ! ,big ,dipp]1 br+s u to ! /> ,pol>is1 or ! ,nor? ,/>1 at ! end ( ! h&le ( ! ,little ,dipp]1 :i* is v close to ! nor? pole ( ! heav5s1 ! direction 9 :i* ! e>?'s axis po9ts4 ,! pole lies on ! l9e connect+ ! /> at ! b5d 9 ! h&le ( ! ,big ,dipp] ) ,pol>is1 & is only "o degree di/ant f ! pole-/>4 ,illu/ration3 ,,may--,,ursa ,,major ,,& ,,ursa ,,m9or ,! di/ance betwe5 ! ,po9t]s is five degrees ( arc1 & ! di/ance f ! m nor!rly ( ^! two />s to ,pol>is is ne>ly ?irty degrees4 ,we may f9d x useful to rememb] ?is 9 e/imat+ di/ances betwe5 objects 9 ! heav5s1 :i* are always giv5 9 angul> measure4 ,a small two & "o-half in* telescope w sep>ate ,pol>is into two />s eighte5 seconds ( arc ap>t4 ,! companion /> is a fa9t :ite /> ( ! n9? magnitude4 ,tw5ty ye>s or s ago x 0 discov]$ ) ! aid ( ! spectroscope t ! bright] ( ! two />s 0 also a d\ble />1 b ! two />s 7 s close toge!r t !y c\ld n be se5 z sep>ate />s 9 any telescope4 ,lat] x 0 f\nd t ! bright] /> 0 9 reality triple1 t is1 x consi/s ( ?ree suns close toge!r4 ,! fa9t :ite companion /> =m$ ) ^! ?ree suns a sy/em ( f\r suns revolv+ ab\t a common c5t] ( gravity4 ,/ill m rec5tly x has be5 discov]$ t ! brighte/ ( ^! f\r suns v>ies regul>ly 9 brightness 9 a p]iod ( a little less ?an f\r days4 ,x belongs to ! important class ( />s kn[n z ,cepheid v>iable />s1 ^: *anges ( light1 x is believ$1 are produc$ by "s p]iodic =m ( di/urbance tak+ place )9 ! />s !mselves4 ,) "o exception1 ,pol>is is ! ne>e/ to ! e>? ( all ^! ,cepheid v>iable />s1 :i* are 9 mo/ in/ances at v great di/ances f ! sol> sy/em4 ,! late/ measurem5ts ( ! di/ance ( ,pol>is %[ t its light takes ab\t two c5turies to travel to ! e>?1 or1 9 o!r words1 t x is di/ant two hundr$ light-ye>s4 ,l all ,cepheid v>iables1 ,pol>is is a giant />4 ,x gives =? ab\t five hundr$ & tw5ty-five times z mu* light z our own sun4 ,if ,pol>is & ! sun 7 plac$ side by side at a di/ance ( ?irty-?ree light-ye>s1 ! sun w\ld appe> z a /> ( ! fif? magnitude1 j well )9 ! range ( visibility ( ! human eye1 :ile ,pol>is w\ld out%9e ,sirius1 ! brighte/ /> 9 ! heav5s4 ,z a practical aid to navigators1 ,pol>is is unsurpass$ 9 importance by any /> ( ! nor!rn hemisph]e ( ! heav5s4 ,at ! equator ! pole-/> lies 9 ! horizon2 at ! nor? pole ( ! e>? x is 9 ! z5i? or directly ov]head4 ,its altitude or height above ! horizon is always equal to ! latitude ( ! place ( obs]vation4 ,z we travel nor?w>d f ! equator t[>d ! pole we see ,pol>is rise high] & high] 9 ! sky4 ,9 ,new ,york ! elevation ( ,pol>is above ! horizon is =ty degrees1 :i* is ! latitude ( ! city4 ,! ,po9t]s indicate ! direction ( ,pol>is & ! true nor?1 :ile ! height ( ,pol>is above ! horizon tells u our latitude4 ,^! k9dly />s direct u by night :5 we are unc]ta9 ( our be>+s1 :e!r we travel by l& or sea or air4 ,!y are ! fri5ds & aids ( explor]s1 navigators & aviators1 :o (t5 turn to !m = guidance4 ,bryant writes ?us beautifully ( ,pol>is 9 8 ,hymn to ! ,nor? ,/>3 ,con/ellations come & climb ! heav5s1 & g4 ,/> ( ! ,pole6 & ?\ do/ see !m set4 ,alone 9 ?y cold skies1 ,?\ keep'/ ?y old unmov+ /ation yet1 ,nor jo9'/ ! dances ( t glitt]+ tra91 ,nor dipp'/ ?y virg9 orb 9 ! blue we/]n ma94 ,on ?y unalt]+ blaze ,! half wreck$ m>9]1 8 compass lo/1 ,fixes 8 /eady gaze1 ,& /e]s1 und\bt+1 to ! fri5dly coa/2 ,& !y :o /ray 9 p]il\s wa/es by night1 ,are glad :5 ?\ do/ %9e to guide _! foot/eps "r4 ,! /> at ! b5d 9 ! h&le ( ! ,big ,dipp]1 call$ ,miz>1 is ( special int]e/4 ,if "o has good eyesight1 he w see close to x a fa9t />4 ,?is is ,alcor1 :i* is ,arabic = ,! ,te/4 ,! two />s are also call$ ! ,horse & ! ,rid]4 ,miz> =ms ) ,alcor :at is kn[n z a wide d\ble />4 ,x is1 9 fact1 ! wide/ ( all d\ble />s4 ,_m />s 9 ! heav5s t appe> s+le to u are sep>at$ by ! telescope into d\ble or triple or multiple />s4 ,!y consi/ ( two or m suns revolv+ ab\t a common c5t]1 kn[n z _! c5t] ( gravity4 ,sometimes ! suns are s close toge!r t ev5 ! mo/ p[]ful telescope w n sep>ate !m4 ,!n a mo/ wond]ful little in/rum5t1 call$ ! spectroscope1 /eps 9 & analyzes ! light ( ! />s & %[s :i* are d\ble & :i* are s+le4 ,a /> %[n to be d\ble by ! spectroscope1 b n by ! telescope1 is call$ a spectroscopic b9>y />4 ,miz> is ( hi/oric int]e/1 z be+ ! fir/ d\ble /> to be detect$ ) ! aid ( ! telescope4 ,a v small telescope w split ,miz> up into two />s4 ,! bright] ( ! two is a spectroscopic b9>y /> beside1 s t x really consi/s ( two suns in/ead ( "o1 ) ! di/ance betwe5 ! two s small t ev5 ! telescope _c sep>ate !m4 ,ab\t ?is sy/em ( ?ree suns :i* we "k z ! /> ,miz>1 ! fa9t /> ,alcor revolves at a di/ance equal to sixte5 ?\s& times ! di/ance ( ! e>? f ! sun4 ,illu/ration3 ,,may--,,leo ,if we foll[ ! imag9>y l9e drawn ?r\gh ! ,po9t]s 9 a s\!rly direction ab\t =ty-five degrees1 we come to ,leo1 ,! ,lion1 "o ( ! zodiacal con/ellations4 ,!re %\ld be no difficulty 9 f9d+ ! con/ellation ,leo1 z its peculi> sickle-%ap$ gr\p ( bright />s makes x di/9ctive f all o!r con/ellations4 ,at ! "t we h m5tion$1 t is1 ! e>ly ev5+ h\rs1 x w lie a little to ! s\?we/ ( ! z5i?4 ,leo is "o ( ! f9e/ con/ellations & is always associat$ ) ! spr+ mon?s because x is !n high 9 ! sky 9 ! ev5+4 ,regulus is ! beautiful :ite /> :i* m>ks ! h&le ( ,! ,sickle1 & ! he>t ( ,leo2 & ,d5ebola is ! second-magnitude /> 9 ! tail ( ,leo4 ,illu/ration3 ,,may--,,corvus ,,& ,,crat] ,due s\? ( ,d5ebola1 ab\t ?irty degrees1 we f9d ! small />-gr\p kn[n z ,crat]1 ,! ,cup1 :i* is compos$ ( r fa9t & inconspicu\s />s4 ,j ea/ ( ,crat] is ! gr\p kn[n z ,corvus1 ,! ,cr[1 :i* =ms a v *>act]i/ic little f\r-sid$ figure ( />s diff]+ v little f "o ano!r 9 brightness4 ,^! two /> gr\ps lie f> to ! s\? 9 our latitudes2 b if we liv$ tw5ty degrees s\? ( ! equator1 we w\ld f9d !m ne>ly ov]head1 at ?is "t ( ! ye>4 ,j s\? ( ,corvus & ,crat] we f9d ,hydra1 "o ( ! con/ellations = ,april :i* ext5ds b5ea? ^! con/ellations & also b5ea? ,virgo1 "o ( ! ,june con/ellations4 ,,vii ,,june ,! />-gr\ps t occupy ! c5t] ( ! cele/ial /age 9 mid-latitudes ( ! nor!rn hemisph]e dur+ ! e>ly ev5+ h\rs ( ,june are ,botes1 (t5 call$ ,! ,hunt]1 7al?\gh ! ^w means ,h]dsman or ,%\t]71 :i* w be f\nd ov]head at ?is "t2 ,virgo1 ,! ,maid51 l>ge/ ( ! zodiacal con/ellations1 ly+ ne>ly due s\?2 ,canes ,v5atici1 ,! ,hunt+ ,dogs2 ,corona ,borealis1 ,! ,nor!rn ,cr[n1 & ,coma ,b]5ices4 ,! gorge\s orange-hu$ ,arcturus 9 ,botes & ! beautiful blui%-:ite ,spica 9 ,virgo1 l a diamond 9 its sp>kl+ radiance1 =m ) ,d5ebola 9 ,leo1 :i* we id5tifi$ 9 ,may1 a huge equal-sid$ triangle t is always associat$ ) ! spr+ & e>ly summ] mon?s4 ,to ! we/ ( ,botes1 bel[ ! h&le ( ! ,big ,dipp]1 is a region :]e !re are few conspicu\s />s4 ,"h w be f\nd ,canes ,v5atici 7,! ,hunt+ ,dogs ) :i* ,botes is suppos$ to be pursu+ ! ,great ,be> ar\nd ! nor? pole71 &1 fur!r s\?1 ,coma ,b]5ices 7,b]nice's ,hair74 ,! bright] ( ! two ,hunt+ ,dogs1 :i* is also ! brighte/ /> 9 ! entire region cov]$ by ^! two con/ellations1 appe>s z a beautiful blue-&-yell[ d\ble /> 9 ! telescope4 ,x 0 nam$ ,cor ,c>oli 7,he>t ( ,*>les7 by ! a/ronom] ,halley 9 honor ( ,*>les ,,ii ( ,engl&1 at ! sugge/ion ( ! c\rt physician1 :o imag9$ x %one m brightly ?an usual ! night be=e ! return ( ,*>les to ,london4 ,( m int]e/ to a/ronom]s is ! magnific5t spiral nebula 9 ?is con/ellation1 kn[n z ! ,:irlpool ,nebula1 appe>+ z a fa9t1 lum9\s pat* 9 ! sky1 ( :i* _m photographs h be5 tak5 ) ! great telescopes4 ,?is entire region1 f ,canes ,v5atici to ,virgo1 ab\nds 9 fa9t spiral nebul t = "s reason n yet und]/ood by a/ronom]s are cr[d$ toge!r 9 ?is "p ( ! heav5s :]e />s are comp>atively few4 ,x is believ$ t !re are betwe5 five hundr$ ?\s& & a million ( ^! spiral nebul 9 ! entire heav5s1 & ! problem ( _! nature & orig9 & di/ance is "o t ! a/ronom]s are v anxi\s to solve4 ,_m wond]ful facts are n[ be+ le>n$ conc]n+ ^! fa9t nebul\s wisps ( light :i*1 ) a few exceptions1 are obs]vable only ) great telescopes4 ,!y reveal _! spiral /ructure m cle>ly to ! photographic plate ?an to ! human eye1 & "s magnific5t photographs ( !m h be5 tak5 ) p[]ful telescopes4 ,coma ,b]5ices1 s\? ( ,canes ,v5atici & s\?we/ ( ,botes1 is a con/ellation t consi/s ( a great numb] ( />s closely cr[d$ toge!r1 & j b>ely visible to ! unaid$ eye4 ,z a result1 x has ! appe>ance ( filmy ?reads ( light1 :i* d\btless sugge/$ its "n to ! imag9ative anci5ts1 :o lov$ to fill ! heav5s ) fanciful creations associat$ ) _! my?s & leg5ds4 ,^! />s =m a mov+ clu/] ( />s e/imat$ to be at a di/ance ( ab\t #bgj light-ye>s f ! sol> sy/ems4 ,illu/ration3 ,,june--,,bo,,tes1 ,,canes ,,v5atici ,,& ,,coma ,,b]5icis ,?is region1 s lack+ 9 int]e/+ objects = ! nak$-eye obs]v]1 is a m9e ( ri*es to ! =tunate possessors ( telescopes2 & ! great telescopes ( ! _w are frequ5tly po9t$ 9 ?is direction1 explor+ ! my/]ies ( space t ab\nd "h4 ,j to ! ea/ ( ,botes is ! exquisite little circlet ( />s kn[n z ,corona ,borealis1 ! ,nor!rn ,cr[n4 ,x consi/s ( six />s arrang$ 9 a ne>ly p]fect semicircle1 & "o w h no difficulty 9 recogniz+ x4 ,its brighte/ />1 ,alpha1 kn[n also by ! "n ( ,alphacca1 is a /> ( ! second magnitude4 ,botes is "o ( ! l>ge/ & f9e/ ( ! nor!rn con/ellations4 ,x c be easily di/+ui%$ by its peculi> kite-%ap$ gr\p+ ( />s or by ! conspicu\s p5tagon 7five-sid$ figure7 ( />s :i* x conta9s4 ,! mo/ s\!rly /> 9 ?is p5tagon is kn[n z ,epsilon ,botes & is "o ( ! f9e/ d\ble />s 9 ! heav5s4 ,! two />s ( :i* x consi/s are respectively orange & gre5i%-blue 9 color4 ,by f> ! f9e/ object 9 ,botes1 h[ev]1 is ! magnific5t ,arcturus1 :i* is ! brighte/ /> 9 ! nor!rn hemisph]e ( ! heav5s4 ,?is /> w be conspicu\s 9 ! ev5+ h\rs ?r\gh\t ! summ] mon?s1 z w also ! less brilliant ,spica 9 ,virgo4 ,"s rec5t measurem5ts %[ t ,arcturus is "o ( our ne>] neighbors among ! />s4 ,its di/ance is n[ e/imat$ to be ab\t tw5ty-"o light-ye>s4 ,t is1 a ray ( light f ?is /> takes tw5ty-"o ye>s to rea* ! e>?1 travel+ at ! rate ( "o hundr$ & eighty-six ?\s& miles p] second4 ,x w\ld seem z if we %\ld h>dly speak ( ,arcturus1 tw5ty-"o light-ye>s away1 z a ne> neighbor1 yet !re are millions ( />s t are f> m di/ant f ! e>?1 & v few t are ne>] to u ?an ,arcturus4 ,! brightness ( ,arcturus is e/imat$ to be ab\t =ty times t ( ! sun4 ,t is1 if ! two bodies 7 side by side1 ,arcturus w\ld give =? =ty times z mu* light & heat z ! sun4 ,arcturus is also "o ( ! mo/ rapidly mov+ />s 9 ! heav5s4 ,9 ! pa/ sixte5 c5turies x has travel$ s f> z to h *ang$ its position among ! o!r />s by z mu* z ! app>5t wid? ( ! moon4 ,mo/ ( ! />s1 9 spite ( _! motions ?r\gh ! heav5s 9 v>i\s directions1 appe> today 9 ! same relative positions 9 :i* !y 7 sev]al ?\s& ye>s ago4 ,x is = ?is reason t ! con/ellations ( ! ,egyptians & ( ! ,greeks & ,romans are ! same con/ellations t we see 9 ! heav5s today4 ,7 all ! />s z rapidly mov+ z ,arcturus1 ! di/9ctive =ms ( ! con/ellations w\ld be pres]v$ = only a v few c5turies4 ,illu/ration3 ,,june--,,virgo ,virgo1 :i* lies s\? & s\?we/ ( ,botes1 is a l>ge1 /raggl+ con/ellation1 consi/+ ( a ,y-%ap$ configuration ( r inconspicu\s />s4 ,x lies 9 ! pa? ( our sun1 moon & planets1 & s is "o ( ! zodiacal con/ellations4 ,! cross 9 ! diagram indicates ! pres5t position ( ! autumnal equ9ox1 ! po9t :]e ! sun crosses ! equator go+ s\?1 & ! position ! sun n[ occupies at ! beg9n+ ( fall4 ,spica1 ! brighte/ /> 9 ,virgo1 is a blui%-:ite1 fir/-magnitude />1 /&+ v mu* alone 9 ! sky4 ,9 fact1 ! ,arabs ref]r$ to ?is /> z ,! ,solit>y ,"o4 ,its di/ance f ! e>? is n kn[n1 b mu/ be v great z x _c be f\nd by ! usual me?ods4 ,! spectroscope %[s t x consi/s ( two suns v close toge!r1 revolv+ ab\t a common c5t] 9 a p]iod ( only f\r days4 ,)9 ! bran*es ( ! ,y 9 ,virgo1 & j to ! nor? ( x1 is ! wond]ful nebul\s region ( ?is con/ellation1 b x takes a p[]ful telescope to %[ ! fa9t spiral nebul t exi/ "h 9 great pr(usion4 ,all ( ^! spirals are rec$+ f ! plane ( ! ,milky ,way ) enorm\s velocities4 ,! spiral nebul are1 9 fact1 ! mo/ rapidly mov+ objects 9 ! heav5s4 ,,viii ,,july ,due ea/ ( ! little circlet ( />s kn[n z ,corona ,borealis1 & almo/ directly ov]head 9 our latitude 7#dj ,n47 ab\t n9e o'clock 9 ! ev5+ 9 ! e>ly "p ( ,july1 is ! l>ge con/ellation ( ,h]cules1 nam$ = ! fam\s h]o ( ,grecian my?ology4 ,!re are no />s ( great brilliancy 9 ?is gr\p1 b x conta9s a l>ge numb] ( fairly bright />s arrang$ 9 ! =m outl9$ 9 ! *>t4 ,! h]o is /&+ ) 8 head1 m>k$ by ! /> ,alpha ,h]culis1 t[>d ! s\?1 & 8 foot re/+ on ! head ( ,draco1 ,! ,dragon1 a f>-nor!rn con/ellation ) :i* we become acqua9t$ 9 ,augu/4 ,illu/ration3 ,,july--,,h]cules ,alpha ,h]culis1 ! be/ kn[n /> 9 ?is con/ellation1 is ( unusual int]e/4 ,n only is x a mo/ beautiful d\ble />1 ! bright] ( ! two />s ( :i* x is compos$ be+ orange1 & ! fa9t] gre5i%-blue1 b x is also a /> t *anges 9 brightness irregul>ly4 ,bo? ! orange & ! blue /> %>e 9 ?is *ange ( brightness4 ,!re are a numb] ( />s 9 ! heav5s t v>y 9 brightness1 "s 9 v regul> p]iods1 & o!rs1 l ,alpha ,h]culis1 irregul>ly4 ,^! latt] />s are ne>ly always deep orange or r$di% 9 color4 ,"o may note ?is v>iation 9 ! brightness ( ,alpha ,h]culis by comp>+ x f "t to "t ) "s ne>by /> t does n v>y 9 brightness4 ,illu/ration3 ,,! ,,great ,,h]cules ,,clu/]--,a ,,univ]se ,,( ,,suns ,tak5 ) #fj-;in* ,reflector ( ! ,mt4 ,wilson ,obs]vatory ,! con/ellation ( ,h]cules is a v ri* field = ! possessor ( ev5 a small telescope4 ,"h are to be f\nd beautifully color$ d\ble />s 9 pr(usion1 &1 9 addition1 two rem>kable clu/]s ( />s4 ,! bright] ( ! two is kn[n z ! ,great ,h]cules ,clu/]4 ,its position is %[n on ! *>t1 &1 "u favorable conditions--t is1 on a cle>1 d>k night1 :5 !re is no moonlight--x may be se5 )\t ! aid ( a telescope z a small1 fa9t pat* ( light4 ,"o w\ld nev] suspect f su* a view :at a wond]ful object ?is clu/] becomes :5 se5 ) ! aid ( a p[]ful telescope4 ,photographs tak5 ) ! great telescopes %[ ?is fa9t wisp ( light z a magnific5t assemblage ( ?\s&s ( />s1 ea* a sun _m times m brilliant ?an our own sun4 ,! cr[d$ appe>ance ( ! />s 9 ! clu/] is due p>tly to ! fact t x is v di/ant f ! e>?1 ?\gh neighbor+ />s 9 ! clu/] are inde$ mu* ne>] to "o ano!r ?an are ! />s 9 ! vic9ity ( our sol> sy/em4 ,x has be5 f\nd t ?is clu/] is s f> away t its light takes ov] ?irty-six ?\s& ye>s to rea* ! e>?4 ,at ! di/ance ( ?is clu/]1 a sun equal 9 brightness to our own sun w\ld be s fa9t t ! mo/ p[]ful telescope 9 ! _w w\ld n %[ x4 ,s we "k t ! />s t are visible 9 ! ,h]cules clu/] are f> m brilliant ?an our sun4 ,a fair-siz$ telescope w %[ ab\t f\r ?\s& />s 9 ?is clu/]1 b ! greate/ telescopes %[ ov] "o hundr$ ?\s& 9 x1 & !re are )\t d\bt _m m too fa9t to be se5 at all4 ,! ,h]cules clu/] is call$ a globul> />-clu/]1 because ! />s 9 x are arrang$ ne>ly 9 ! =m ( a sph]e4 ,!re are 9 ! heav5s ab\t n9ety su* clu/]s ^: di/ances h be5 f\nd1 & !y are among ! mo/ di/ant ( all objects4 ,mo/ ( !m are v fa9t1 & a few are ov] two hundr$ ?\s& light-ye>s di/ant f ! e>?4 ,! ,h]cules clu/] is "o ( ! ne>e/ & is ! mo/ not$ ( all ( ^! globul> clu/]s4 ,x is consid]$ to be "o ( ! f9e/ objects 9 ! heav5s4 ,! o!r clu/] 9 ,h]cules is also v f9e1 b n to be comp>$ ) ?is "o4 ,illu/ration3 ,,july--,,ophiu*us ,,& ,,s]p5s ,j to ! s\? ( ,h]cules are two con/ellations1 ,ophiu*us1 ,! ,s]p5t-,be>]1 & ,s]p5s1 ,! ,s]p5t1 :i* are s int]m+l$ t x is difficult to di/+ui% !m4 ,!re are 9 ^! two con/ellations1 z 9 ,h]cules1 no />s ( unusual brilliancy1 b a l>ge numb] ( fairly bright />s4 ,! brighte/ /> 9 ,ophiu*us is kn[n z ,alpha ,ophiu*i & x m>ks ! head ( ! ,s]p5t-,be>]4 ,! two />s1 ,alpha ,ophiu*i & ,alpha ,h]culis1 are close toge!r1 be+ sep>at$ by a di/ance ab\t equal to t betwe5 ! ,po9t]s ( ! ,big ,dipp]4 ,alpha ,ophiu*i is ! bright] ( ! two1 & x is f>!r ea/4 ,ophiu*us1 accord+ to "o leg5d1 0 once a physician on e>?1 & 0 s successful z a heal] t he c\ld raise ! dead4 ,pluto1 ! god ( ! l[] _w1 became al>m$ = fe> 8 k+dom w\ld become depopulat$1 & p]suad$ ,jupit] to remove ,ophiu*us to a heav5ly abode1 :]e he w\ld be less tr\blesome4 ,! s]p5t is suppos$ to be a symbol ( 8 heal+ p[]s4 ,! head ( ,s]p5s is m>k$ by a gr\p ( fa9t />s j s\? ( ,corona ,borealis & s\?we/ ( ,h]cules4 ,f "h a l9e ( fairly bright />s m>ks ! c\rse ( ,s]p5s s\?w>d to ! h& ( ,ophiu*us4 ,two />s close toge!r & ne>ly equal 9 brightness m>k ! h& ) :i* ! h]o grasps ! body ( ! s]p5t4 ,! o!r h& is m>k$ by an equally bright s+le /> "s di/ance to ! ea/w>d :]e ! two con/ellations aga9 meet4 ,ophiu*us is ?us repres5t$ z hold+ ! s]p5t ) bo? h&s4 ,x is n an easy matt] to make out ! outl9es ( ^! /raggl+ gr\ps1 b !re are 9 !m sev]al pairs ( />s ne>ly equal 9 brightness & ab\t z ev5ly spac$ z ! two />s 9 ! "o h& ( ,ophiu*us1 & ^!1 z well z ! diagram1 w be ( aid 9 trac+ ! two gr\ps4 ,j s\? ( ,s]p5s & ,ophiu*us lies "o ( ! mo/ beautiful & easily recogniz$ con/ellations 9 ! heav5s4 ,?is is ! con/ellation ( ,scorpio1 ,! ,scorpion1 :i* w be f\nd n f> above ! s\!rn horizon at ?is "t4 ,! small con/ellation ( ,libra1 ,! ,scales1 :i* lies j to ! nor?we/ ( ,scorpio1 0 at "o "t a "p ( ?is con/ellation & repres5t$ ! creature's claws1 b "s c5turies ago its "n 0 *ang$ to ,libra4 ,bo? ,scorpio & ,libra are numb]$ among ! twelve zodiacal con/ellations--t is1 !y lie along ! ecliptic1 or app>5t ye>ly pa? ( ! sun among ! />s4 ,scorpio is ! mo/ brilliant & int]e/+ ( all ! zodiacal gr\ps4 ,! he>t ( ! ,scorpion is m>k$ by ! magnific5t fir/-magnitude /> ,ant>es1 :i* is ( a deep r$di% color4 ,! "n signifies ,rival ( ,ares 7,m>s74 ,x is s call$ because x is ! "o /> 9 ! heav5s t mo/ closely resembles ,m>s1 & x might be mi/ak5 = ! ruddy planet if "o 7 n famili> ) ! con/ellations4 ,at times1 :5 ,m>s is at a consid]able di/ance f ! e>?1 x is almo/ equal 9 brightness & g5]al appe>ance to ?is gl[+ r$ /> 9 ! he>t ( ! ,scorpion4 ,9 its trips ar\nd ! sun1 ,m>s passes occasionally v close to ,ant>es1 & ! two !n pres5t a v /rik+ appe>ance4 ,illu/ration3 ,,july--,,libra ,,& ,,scorpio ,) a telescope ( m$ium size1 "o w f9d an exquisite little gre5 companion-/> close to ,ant>es4 ,! little companion is s close to ,ant>es t x is difficult to f9d x 9 ! gl>e ( light f its m brilliant neighbor4 ,ant>es is "o ( ! giant />s ( ! univ]se4 ,9 fact x is1 s f> z we "k1 ! greate/ ( all ! giants4 ,its diamet] is m ?an five hundr$ times t ( our own sun & ne>ly twice t ( ! giant /> ,betelgeuze 9 ,orion4 ,if plac$ at ! c5t] ( ! sol> sy/em its surface w\ld lie f> beyond ! orbit ( ,m>s4 ,bo? ,ophiu*us & ,scorpio are cross$ by ! ,milky ,way1 t broad belt ( numb]less fa9t />s t encircles ! heav5s4 ,"s ( ! mo/ wond]ful & beautiful regions ( ! ,milky ,way are to be f\nd 9 ^! two con/ellations4 ,at v>i\s times 9 ! pa/1 !re h sudd5ly fla%$ =? brilliant />s 9 ! ,milky ,way :i* are kn[n z tempor>y />s1 or nov4 ,^! outbur/s signify t "s cele/ial cata/rophe has tak5 place1 ! nature or cause ( :i* is n cle>ly und]/ood4 ,"s ( ! mo/ brilliant ( ^! outbur/s h occurr$ 9 ^! two con/ellations4 ,! life ( a nova is v %ort1 a matt] ( a few mon?s1 & x rapidly s9ks into oblivion1 s no?+ is to be se5 ( "s ( ! mo/ brilliant ( all ^! />s t h appe>$ 9 ?is region 9 ! pa/4 ,a few are /ill fa9tly visible 9 l>ge telescopes4 ,,ix ,,augu/ ,x 0 "o ( ! twelve labors ( ,h]cules1 ! h]o ( ,grecian my?ology1 to vanqui% ! dragon t gu>d$ ! gold5 apples 9 ! g>d5 ( ! ,hesp]ides4 ,among ! con/ellations = ,july we f\nd ! l>ge gr\p ( />s t repres5ts ! h]o himself1 & ?is mon? we f9d j to ! nor? ( ,h]cules ! head ( ,draco1 ,! ,dragon4 ,! foot ( ! h]o re/s ^u ! dragon's head1 :i* is outl9$ by a gr\p ( f\r fairly bright />s =m+ a quadrilat]al or f\r-sid$ figure4 ,! brighte/ /> 9 ?is gr\p passes 9 its daily circuit ( ! pole almo/ ?r\gh ! z5i? ( ,london4 ,t is1 z x crosses ! m]idian ( ,london1 x is almo/ exactly ov]head4 ,f ! head ( ,draco1 ! creature's body c be trac$ 9 a long l9e ( />s curv+ fir/ ea/w>d1 !n nor?w>d1 t[>d ! pole-/> to a po9t above ,h]cules1 :]e x b5ds %>ply we/w>d4 ,! body ( ! mon/] lies *iefly betwe5 its head & ! b[l ( ! ,little ,dipp]4 ,! tail ext5ds 9 a long l9e ( fa9t />s midway betwe5 ! two ,dipp]s1 or ! con/ellations ( ,ursa ,major & ,ursa ,m9or1 ! tip ( ! tail ly+ on ! l9e connect+ ! ,po9t]s ( ! ,big ,dipp] ) ! pole-/> ,pol>is4 ,draco1 z well z ,ursa ,major & ,ursa ,m9or1 is a circumpol> con/ellation 9 our latitude2 t is1 x makes its circuit ( ! pole )\t at any "t dipp+ bel[ ! horizon 9 latitudes nor? ( #dj4 ,x is1 !re=e1 visible at all h\rs ( ! night 9 mid-latitudes ( ! nor!rn hemisph]e1 b is se5 to ! be/ advantage dur+ ! e>ly ev5+ h\rs 9 ! summ] mon?s4 ,!re are no rem>kable />s 9 ?is con/ellation ) ! exception ( ,alpha1 :i* lies halfway betwe5 ! b[l ( ! ,little ,dipp] & ,miz>1 ! /> at ! b5d 9 ! h&le ( ! ,big ,dipp]4 ,illu/ration3 ,,augu/--,,draco ,,& ,,lyra ,ab\t f\r ?\s& sev5 hundr$ ye>s ago1 ?is /> 0 ! pole-/>--ly+ ev5 ne>] to :at 0 !n ! nor? pole ( ! heav5s ?an ,pol>is does to ! pres5t position ( ! pole4 ,! sun & moon ex]t a pull on ! bulg+ equatorial regions ( ! e>?1 :i* t5ds to draw ! plane ( ! e>?'s equator d[n into ! plane ( ! ecliptic4 ,?is causes ! ,precession ( ! ,equ9oxes & at ! same "t a sl[ revolution ( ! e>?'s axis ( rotation ab\t ! pole ( ! ecliptic4 ,! nor? pole ( ! heav5s z a result describes a circle ab\t ! pole ( ! ecliptic ( radius #bc-a_/b 9 a p]iod ( #be1hjj ye>s4 ,ea* bright /> t lies ne> ! circumf]5ce ( ?is circle becomes 9 turn ! pole-/> sometime )9 ?is p]iod4 ,! /> ,alpha1 9 ,draco1 _h its turn at be+ pole-/> "s =ty-sev5 c5turies ago4 ,pol>is is n[ a little ov] a degree f ! nor? pole ( ! heav5s4 ,dur+ ! next two c5turies x w cont9ue to approa* ! pole until x comes )9 a qu>t] ( a degree ( x1 :5 its di/ance f ! pole w beg9 to increase aga94 ,ab\t twelve ?\s& ye>s h5ce ! magnific5t ,vega1 ^: acqua9tance we w n[ make1 w be ! mo/ brilliant & beautiful ( all pole-/>s4 ,vega 7,arabic = ,fall+ ,eagle7 is ! respl5d5t1 blui%-:ite1 fir/-magnitude /> t lies 9 ! con/ellation ( ,lyra1 ,! ,lyre or ,h>p1 a small1 b important1 con/ellation j ea/ ( ,h]cules & a little to ! s\!a/ ( ! head ( ,draco4 ,vega is almo/ exactly equal 9 brightness to ,arcturus1 ! orange-color$ /> 9 ,botes1 n[ ly+ we/ ( ! m]idian 9 ! e>ly ev5+ h\rs4 ,x is also a ne> neighbor ( ! sol> sy/em1 its light tak+ some?+ l =ty ye>s to travel to ! e>?4 ,vega is c>ri$ ne>ly ?r\gh ! z5i? ( ,wa%+ton & all places 9 ! same latitude by ! app>5t daily rotation ( ! heav5s4 ,x is a /> t we h no difficulty 9 recogniz+1 ow+ to ! pres5ce ( two ne>by />s t =m1 ) x1 a small equal-sid$ triangle ) sides only two degrees 9 ext5t4 ,if our own sun 7 at ! di/ance ( ,vega1 x w\ld n appe> z bright z "o ( ^! fa9t />s1 s mu* m brilliant is ?is magnific5t sun ?an our own4 ,! two fa9t />s t foll[ s closely aft] ,vega & =m ! little triangle ) x are also ( p>ticul> int]e/4 ,epsilon ,lyr1 :i* is ! nor!rn "o ( ^! two />s1 may be us$ z a te/ ( ke5 eyesight4 ,x is ! f9e/ example 9 ! heav5s ( a quadruple />--t is1 a d\ble-d\ble />4 ,a ke5 eye c j sep>ate ?is /> into two )\t a telescope1 & ) ! aid ( a telescope1 ea* ( ! two splits up into two />s1 mak+ f\r />s 9 place ( ! "o visible to ! av]age eye4 ,zeta1 ! o!r ( ! two />s t =m ! little triangle ) ,vega1 is also a f9e d\ble />4 ,! /> t lies almo/ 9 a /raight l9e ) ,epsilon & ,zeta & a %ort di/ance to ! s\? ( !m is a v int]e/+ v>iable /> kn[n z ,beta ,lyr4 ,its brightness *anges v consid]ably 9 a p]iod ( twelve days & tw5ty-two h\rs4 ,?is *ange ( brightness is due to ! pres5ce ( a companion />4 ,! two />s are 9 mutual revolution1 & _! motion is view$ at su* an angle f ! e>? t1 9 ea* revolution1 "o /> is eclips$ by ! o!r1 produc+ a v>iation 9 ! am\nt ( light t rea*es our eyes4 ,by comp>+ ?is /> f day to day ) ! /> j a %ort di/ance to ! s\!a/ ( x1 :i* does n v>y 9 brightness1 we c obs]ve = ourselves ?is *ange 9 ! light ( ,beta ,lyr4 ,!re are a numb] ( />s 9 ! heav5s t v>y 9 brightness 9 ! same mann] z ,beta ,lyr1 & !y are call$ eclips+-v>iable />s4 ,on ! l9e connect+ ,beta ,lyr ) ! /> s\!a/ ( x & "o-?ird ( ! di/ance f ,beta to ?is />1 lies ! not$ ,r+ ,nebula 9 ,lyra1 :i* is a beautiful object ev5 9 a small telescope4 ,x consi/s ( a r+ ( lum9\s gas surr\nd+ a c5tral />4 ,! /> %9es ) a brilliant1 blui%-:ite light & is visible only 9 p[]ful telescopes ?\gh x is easily photograph$ s9ce x gives =? rays to :i* ! photographic plate is p>ticul>ly s5sitive4 ,9 small telescopes ! c5tral "p ( ?is nebula appe>s d>k b ) a p[]ful telescope a fa9t light may be se5 ev5 9 ! c5tral portion ( ! nebula4 ,?is is "o ( ! mo/ int]e/+ & beautiful telescopic objects 9 ! heav5s4 ,x is 9 ! g5]al direction ( ! con/ellation ( ,lyra t our sol> sy/em is spe$+ at ! rate ( m ?an a million miles a day4 ,?is po9t t[>d :i* we are mov+ at su* trem5d\s spe$ lies a little to ! s\?we/ ( ,vega1 on ! bord] betwe5 ! con/ellations ( ,lyra & ,h]cules1 & is spok5 ( z ,! ,apex ( ! ,sun's ,way4 ,illu/ration3 ,,augu/--,,sagitt>ius ,9 ! s\!rn sky we h ?is mon? ! con/ellation ( ,sagitt>ius1 ,! ,ar*]1 :i* is j to ! ea/ ( ,scorpio & a consid]able di/ance s\? ( ,lyra4 ,x c be recogniz$ by its peculi> =m1 :i* is t ( a %ort-h&l$ milk dipp]1 ) ! b[l turn$ t[>d ! s\? & a trail ( bright />s runn+ f ! end ( ! h&le t[>d ! s\?we/4 ,?is is "o ( ! zodiacal gr\ps :i* conta9 no fir/-magnitude />s1 b a numb] ( ! second & ?ird magnitude4 ,x is cross$ by ! ,milky ,way1 :i* is v wond]ful 9 its /ructure at ?is po9t4 ,"s a/ronom]s believe t "h--among ! />-cl\ds & mi/s ( nebul\s light :i* are int]m+l$ ) d>k lanes & holes1 9 reality d>k nebul--lies ! c5t] ( ! va/ sy/em ( />s & nebul 9 :i* our entire sol> sy/em is b ! m]e/ speck4 ,"s ( ! gr&e/ views ?r\gh ! telescope are also to be obta9$ 9 ?is beautiful con/ellation ( ,sagitt>ius1 :i* is s f> s\? t x is se5 to bett] advantage 9 ! tropics ?an 9 ! mid-latitudes ( ! nor!rn hemisph]es4 ,x ,,septemb] ,"o ( ! mo/ beautiful con/ellations ( ! nor!rn hemisph]e is ,cygnus1 ,! ,swan1 :i* is 9 ! z5i? 9 mid-latitudes ab\t n9e o'clock 9 ! ev5+ ! middle ( ,septemb]4 ,x lies directly 9 ! pa? ( ! ,milky ,way :i* /ret*es diagonally across ! heav5s f ! nor!a/ to ! s\?we/ at ?is "t4 ,9 ,cygnus1 ! ,milky ,way divides into two bran*es1 "o pass+ ?r\gh ,ophiu*us & ,s]p5s to ,scorpio1 & ! o!r ?r\gh ,sagitta & ,aquila to ,sagitt>ius1 to meet aga9 9 ! s\!rn con/ellation ( ,ara1 j s\? ( ,scorpio & ,sagitt>ius4 ,on cle>1 d>k ev5+s1 :5 !re is no moonlight1 ?is long1 d>k rift 9 ! ,milky ,way c be se5 v cle>ly4 ,9 ,cygnus1 z 9 ,ophiu*us1 ,scorpio1 & ,sagitt>ius we f9d wond]ful />-cl\ds1 consi/+ ( numb]less />s s di/ant f u &1 !re=e1 s fa9t t !y d n appe> z di/9ct po9ts ( light except 9 ! greate/ telescopes4 ,x is ! comb9$ light f ^! numb]less />s t _c be se5 sep>ately t produces ! impression ( />s mass$ 9 cl\ds ( nebul\s light & gives to ?is girdle ( ! heav5s its "n ( ! ,milky ,way4 ,9 ,cygnus1 z 9 a numb] ( o!r con/ellations ( bo? hemisph]es1 ! ,milky ,way is cross$ by d>k rifts & b>s & is v complicat$ 9 its /ructure4 ,x is 9 ,cygnus1 also1 t "o may see ) ! aid ( p[]ful telescopes ! va/1 irregul>1 lum9\s nebul1 t are l great cl\ds ( fi]y mi/4 ,^! nebul are ( enorm\s ext5t1 = !y cov] space t c\ld be occupi$ by hundr$s ( />s4 ,illu/ration3 ,,septemb]--,,cygnus ,cygnus is a con/ellation t is fill$ ) ! wond]s & my/]ies ( space & t ab\nds 9 beautiful objects ( v>i$ k9ds4 ,x is a region "o nev] tires ( explor+ ) ! telescope4 ,! pr9cipal />s 9 ,cygnus =m ! well-kn[n ,nor!rn ,cross1 ) ! beautiful1 :ite1 fir/-magnitude /> ,d5eb1 or ,arid$1 z x is sometimes call$1 at ! top ( ! cross1 & ,albireo1 ! orange-&-blue d\ble /> at ! foot4 ,albireo1 among all ! pairs ( contra/+ hues1 has ! di/9ction ( be+ consid]$ ! f9e/ d\ble /> 9 ! heav5s = small telescopes4 ,?is /> m>ks ! head ( ,! ,swan1 z well z ! foot ( ! ,nor!rn ,cross1 & ,d5eb m>ks ! tail ( ,! ,swan4 ,a %ort di/ance to ! s\!a/ ( ,d5eb1 on ! "r w+ ( ,! ,swan1 is a fam\s little />1 #fa ,cygni1 b>ely visible to ! nak$ eye & =m+ a little triangle ) two bright] />s to ! ea/4 ,?is /> has ! di/9ction ( be+ ! fir/ "o to h its di/ance f ! sol> sy/em det]m9$4 ,! fam\s ma!matician & a/ronom] ,bessel accompli%$ ?is difficult feat 9 ! ye> #ahch4 ,s9ce t day1 ! di/ances ( _m />s h be5 f\nd by v>i\s me?ods1 b ( all ^! />s only f\r or five are kn[n to be ne>] to u ?an #fa ,cygni4 ,its di/ance is ab\t eight light-ye>s1 s its light takes ab\t eight ye>s to travel ! di/ance t sep>ates x f ! sol> sy/em4 ,z a result1 we see x n z x is tonight1 b z x 0 at ! "t :5 ! light n[ ent]+ our eyes fir/ />t$ on its j\rney eight ye>s ago4 #fa ,cygni is also a d\ble />1 & ! comb9$ light ( ! two />s gives =? only "o-t5? z mu* light z our own sun4 ,mo/ ( ! brilliant fir/-magnitude />s give =? _m times z mu* light z ! sun2 b among ! fa9t] />s1 we f9d "s t appe> fa9t because !y are v di/ant1 & "s t are fa9t because !y are dw>f />s & h little light to give =?4 ,to ! class ( ne>by1 feebly-%9+ dw>f />s #fa ,cygni belongs4 ,d5eb1 on ! o!r h&1 is "o ( ! giant />s1 & is at an immeasurably great di/ance f ! sol> sy/em4 ,j s\? ( ,cygnus 9 ! ea/]n bran* ( ! ,milky ,way lie ,sagitta1 ,! ,arr[1 & ,aquila1 ,! ,eagle4 ,n f> to ! nor!a/ ( ,aquila is ! odd little con/ellation ( ,delph9us1 ,! ,dolph91 popul>ly ref]r$ to z ,job's ,c(f94 ,!re w be no difficulty 9 f9d+ ?is small />-gr\p1 ow+ to its peculi> diamond-%ap$ configuration4 ,its five pr9cipal />s are ( ! f\r? magnitude4 ,x is 9 ! con/ellation ( ,delph9us t ! mo/ di/ant kn[n object 9 ! heav5s is locat$4 ,?is is ! globul> /> clu/] kn[n only by its catalogue numb] ( ,n4,g4,c4 #gjjf4 ,x is e/imat$ to be at a di/ance ( #bbj1jjj light-ye>s f ! e>?4 ,sagitta1 ,! ,arr[1 lies midway betwe5 ,albireo & ! brilliant ,altair 9 ,aquila4 ,! po9t ( ! arr[ is indicat$ by ! /> t is f>!/ ea/2 & ! fea!r1 by ! two fa9t />s to ! we/4 ,l ,delph9us1 ?is con/ellation is v small & conta9s no objects ( p>ticul> int]e/4 ,altair 7,fly+ ,eagle7 is ! brilliant :ite /> ( ! fir/ magnitude 9 ,aquila & is att5d$ by two fa9t] />s1 "o on ei!r side1 at ne>ly equal di/ances f x4 ,^! two />s s]ve readily to di/+ui% ?is />1 all ?ree />s be+ ne>ly 9 a /raight l9e4 ,altair is "o ( ! ne>] />s1 its di/ance f ! e>? be+ ab\t sixte5 light-ye>s4 ,x gives =? ab\t t5 times z mu* light z ! sun4 ,illu/ration3 ,,septemb]--,,delph9us1 ,,aquila ,,& ,,sagitta ,we _c leave ! con/ellation ( ,aquila )\t ref]r+ to ! wond]ful tempor>y /> or nova1 kn[n z ,nova ,aquil ,no4 #c 7because x 0 ! ?ird nova to appe> 9 ?is con/ellation71 :i* appe>$ 9 ! position indicat$ on ! *>t ^u ! eigh? ( ,june1 #aiah4 ,a few days previ\s to ?is date1 !re 0 9 ?is position an extremely fa9t />1 invisible to ! nak$ eye & 9 small telescopes4 ,?is fact became kn[n f lat] exam9ations ( old photographs ( ?is region t _h be5 tak5 at ! ,h>v>d ,college ,obs]vatory1 :]e ! photograph+ ( ! heav5s is c>ri$ on regul>ly = ! purpose ( hav+ a record ( cele/ial *anges & happ5+s4 ,cl\ds prev5t$ ! obta9+ ( any photographs ( ?is "p ( ! heav5s on ! f\r nights prec$+ ! eigh? ( ,june1 b on ?is ev5+ !re %one 9 ! place ( ! fa9t telescopic />1 a wond]ful tempor>y />1 or nova1 :i* 0 de/9$ on ! next ev5+ to out%9e all />s 9 ! heav5s1 ) ! exception ( ! brighte/ ( all1 ,sirius1 :i* x closely rival$ 9 brilliancy at ! height ( its outbur/4 ,)9 less ?an a week's "t1 ?is fa9t /> 9 ! ,milky ,way = "s my/]i\s reason increas$ 9 brightness _m ?\s&fold4 ,su* outbur/s h be5 record$ be=e1 b on r>e occasions1 h[ev]4 ,no /> s9ce ! appe>ance ( ! nova kn[n z ,kepl]'s ,/>1 9 ! ye> #afjd1 :i* at its greate/ brilliancy rival$ ,jupit]1 %one ) su* spl5dor or attract$ s mu* att5tion z ,nova ,aquil4 ,9 ! ye> #aija1 !re appe>$ 9 ! con/ellation ( ,p]seus a /> kn[n z ,nova ,p]sei :i* at its brighte/ surpass$ ,vega1 b its spl5dor 0 n z great z t ( ! wond]ful nova ( #aiah4 ,x speaks well = ! zeal & int]e/ ( amateur a/ronom]s1 z well z = _! acqua9tance ) ! />s1 t ,nova ,p]sei 0 discov]$ by an amateur a/ronom]1 ,dr4 ,&]son1 & t among ! deluge ( telephone calls & telegrams receiv$ at ! ,h>v>d ,college ,obs]vatory on ! night ( ,june #h?1 ann\nc+ indep5d5t discov]ies ( ! new />1 7 _m f non-pr(essional a/ronom]s4 ,l all />s ( ?is class1 ,nova ,aquil ,no4 #c sank rapidly into oblivion4 ,9 a few weeks x 0 only a ?ird-magnitude />2 a few weeks m & x 0 invisible )\t a telescope4 ,_m wond]ful & int]e/+ *anges h be5 record$ 9 ! appe>ance ( ?is />1 h[ev]1 ev5 aft] x became visible only 9 ! telescope4 ,soon aft] its outbur/ x appe>$ to develop a nebul\s envelope1 z h o!r novas be=e x4 ,x %[$ 9 addition _m ( ! peculi>ities ( ! nebul1 ?\gh ! c5tral /> rema9$ visible z be=e ! outbur/4 ,a/ronom]s are /ill 9 d\bt z to ! cause ( ^! outbur/s1 :i* c]ta9ly indicate cele/ial cata/rophies ( "s =m on a gigantic scale4 ,all novas possess "o *>act]i/ic 9 common--t ( appe>+ exclusively 9 ! ,milky ,way2 & ano!r *>act]i/ic is ! developm5t ( a nebul> envelope aft] ! outbur/ ( greate/ brightness4 ,9 "s cases tempor>y />s h be5 kn[n to be v>iable 9 brightness = ye>s be=e ! great outbur/4 ,su* a /> 0 ,nova ,aquila1 = ! exam9ation ( photographs ( ?is region tak5 "s ye>s previ\s %[$ v>iations 9 its brightness = a p]iod ( ?irty ye>s at lea/4 ,up to ! beg9n+ ( ?is c5tury only ab\t ?irty novas _h be5 discov]$4 ,s9ce t date1 ?anks to ! vigilance ( ! a/ronom]s ( today & to ! aid ( photography1 m h be5 discov]$ ?an 9 all ! prec$+ c5turies4 ,^! outbur/s ( new />s appe> to be n s r>e z ! e>li] a/ronom]s believ$1 ?\gh great outbur/s z brilliant z t ( ,nova ,aquila are v uncommon4 ,,xi ,,octob] ,! con/ellations t w be f\nd ne>e/ ! m]idian 9 e>ly ,octob] ev5+s are ! circumpol> con/ellations ,cepheus & ,cassiopeia1 & 9 ! s\!rn sky1 ,capricornus & ,aqu>ius4 ,cepheus1 ,! ,k+1 & ,cassiopeia1 8 ,que51 ( :om we %all h m to say lat] 9 connection ) ! con/ellations ( ,&rom$a & ,p]seus1 sit fac+ ! nor? pole ( ! heav5s opposite ,ursa ,major1 ,! ,great ,be>1 famili> to u "u ! "n ( ,! ,big ,dipp]4 ,! foot ( ,cepheus re/s ^u ! tail ( ! ,little ,be>1 & ! /> f>!/ nor? 9 ! diagram is 9 ! left knee4 ,! head is m>k$ by a small triangle ( fa9t />s1 %[n 9 ! diagram4 ,"o ( ^! ?ree fa9t />s--! "o f>!/ ea/--kn[n z ,delta ,cephei1 is a v rem>kable v>iable />1 *ang+ p]iodically 9 brightness e five & "o-?ird days4 ,its "n has be5 giv5 to a l>ge class ( v>iable />s--! ,cepheid v>iables--t resemble ,delta ,cephei 9 be+ giant suns1 fa9t only because !y are at v great di/ances f ! e>?1 & v>y+ 9 brightness ) ! greate/ regul>ity 9 p]iods t range f a few h\rs to sev]al weeks4 ,x has be5 f\nd t ! long] ! p]iod ( light *ange ! great] is ! /> 9 size & brightness4 ,! ,cepheids ( longe/ p]iod are #aj1jjj times m brilliant ?an our own sun4 ,cepheus conta9s no v bright or conspicu\s />s4 ,alpha ,cephei1 ! brighte/ /> 9 ! gr\p1 m>ks ,! ,k+'s "r %\ld]4 ,x is ! /> f>!/ to ! we/ 9 ! diagram1 & is only a ?ird-magnitude />4 ,illu/ration3 ,,octob]--,,cassiopeia ,,& ,,cepheus ,cassiopeia is a con/ellation ) :i* e "o 9 ! nor!rn hemisph]e %\ld be famili>1 ow+ to its v di/9ctive ,w-%ape & its f> nor!rn position1 :i* br+s x conspicu\sly into view ?r\gh\t ! cle> fall & w9t] ev5+s4 ,cassiopeia is pictur$ 9 all /> atlases t %[ ! my?ological figures1 ) h] face t[>d ! nor? pole4 ,! />s 9 ! ,w outl9e ! body4 ,alpha1 ! /> f>!/ s\? 9 ! diagram m>ks ! brea/ ( ,cassiopeia4 ,h] head & uplift$ h&s are repres5t$ by fa9t />s s\? ( ,alpha4 ,?is /> is occasionally ref]r$ to by its ,arabic "n ( ,s*$ir4 ,beta1 ! lead] ( all ! />s 9 ! ,w 9 _! daily we/w>d motion1 is also kn[n by an ,arabic "n1 ,caph4 ,9 ! con/ellation ( ,cassiopeia !re appe>$ 9 ! ye> #aegb ,a4,d41 a wond]ful tempor>y /> :i* sudd5ly1 )9 a few days' "t1 became z brilliant z ! planet ,v5us & 0 cle>ly visible 9 broad daylight4 ,?is /> is (t5 ref]r$ to z ,ty*o's ,/>1 because x 0 obs]v$1 & its position v accurately det]m9$1 by ,ty*o ,brahe1 "o ( ! mo/ fam\s ( ! old a/ronom]s4 ,?is /> rema9$ visible to e "o = ab\t sixte5 mon?s1 b x f9ally fad$ completely f view1 & x is believ$ t a fa9t1 nebul\s r$ />1 visible only 9 ! telescope & close to ! position record$ by ,ty*o1 repres5ts ! smold]+ emb]s ( ! /> t once /ruck t]ror to ! he>ts ( ! sup]/iti\s & ignorant among all ! nations ( ,europe1 :o took x to be a sign t ! end ( ! _w 0 at h&4 ,bo? ,cassiopeia & ,cepheus lie 9 ! pa? ( ! ,milky ,way1 :i* rea*es its f>!/ nor!rn po9t 9 ,cassiopeia & passes f ,cepheus 9 a s\!rly direction into ! con/ellation ( ,cygnus4 ,illu/ration3 ,,octob]--,,aqu>ius ,,& ,,capricornus ,turn+ n[ to s\!rn skies1 we f9d on & to ! we/ ( ! m]idian at ?is "t ! r inconspicu\s zodiacal con/ellation ( ,capricornus1 ,! ,goat4 ,x conta9s no />s ( great brightness & is *iefly rem>kable = ! fact t x conta9s "o ( ! few d\ble />s t c be se5 )\t ! aid ( a telescope4 ,! lea/ di/ance 9 ! heav5s t ! unaid$ human eye c sep>ate is ab\t f\r m9utes ( arc4 ,! /> ,alpha 9 ,capricornus is made up ( two />s sep>at$ by a di/ance ( six m9utes ( arc1 s t any "o c readily see t x consi/s ( two />s v close toge!r4 ,?is />1 ,alpha1 w be f\nd 9 ! extreme we/]n "p ( ! con/ellation1 & c be/ be locat$ 9 conjunction ) ! /> ,beta1 :i* is slightly bright] & lies b a %ort di/ance almo/ due s\? ( ,alpha1 ! two />s /&+ some:at alone 9 ?is "p ( ! heav5s4 ,to ! nor? & ea/ ( ,capricornus we f9d ,aqu>ius1 :i* is also a zodiacal con/ellation4 ,aqu>ius is ! ,wat]-,be>]1 & ! wat] j> :i* he c>ries is repres5t$ by a small1 b di/9ct1 ,y ( />s f :i* fl[s a /ream ( fa9t />s t[>d ! s\!a/ & s\?4 ,aqu>ius1 l ,capricornus1 is a r un9t]e/+ con/ellation1 z x is made up ( inconspicu\s ?ird- & f\r?-magnitude />s4 ,! entire region cov]$ by ^! two gr\ps ( />s is rem>kably b>r51 s9ce x conta9s n a s+le fir/- or ev5 second-magnitude /> & little to attract ! obs]v]'s eye4 ,to relieve ! b>r5ness ( ?is region1 !re appe>s j to ! s\? ( ,aqu>ius & s\!a/ ( ,capricornus1 sp>kl+ l[ 9 ! s\!rn sky on crisp ,octob] ev5+s1 ! beautiful fir/-magnitude /> ,fomalhaut 9 ! small s\!rn con/ellation ( ,piscis ,au/ralis1 ,! ,s\!rn ,fi%4 ,?is /> is ! f>!/ s\? ( all ! brilliant fir/-magnitude />s t c be se5 f ! middle latitudes ( ! ,nor!rn ,hemisph]e4 ,! con/ellation 9 :i* x lies is s close to ! s\!rn horizon 9 our latitudes t x _c be se5 to any advantage1 & x is at be/ v inconspicu\s1 conta9+ no o!r objects ( int]e/4 ,fomalhaut _c be mi/ak5 = any o!r /> visible at ?is "t ( ye> 9 ! ev5+1 s9ce x /&s 9 su* a solit>y position f> to ! s\?4 ,at ! "t ( :i* we are writ+ x w be f\nd a few degrees ea/ ( ! m]idian4 ,,xii ,,novemb] ,directly s\? ( ,cassiopeia & ,cepheus1 ! circumpol> con/ellations ) :i* we became acqua9t$ la/ mon?1 & almo/ ov]head 9 our latitudes 9 ! e>ly ev5+ h\rs ( ,novemb]1 lie ,pegasus1 ,! ,w+$ ,horse1 & ,&rom$a1 ,! ,woman ,*a9$4 ,accord+ to ! leg5d1 ,cepheus 0 k+ ( ,e?iopia1 & ,cassiopeia 0 ! beautiful1 b va91 que5 :o d>$ to comp>e h]self 9 beauty ) ! sea-nymphs4 ,?is s enrag$ ! nymphs t1 z a puni%m5t = h] presumption1 !y decid$ to s5d a t]rible sea-mon/] to ravage ! coa/ ( ! k+dom4 ,! k+ & que51 ^u consult+ ! oracle1 f\nd t ! only way to av]t ?is calamity w\ld be to *a9 _! daught] ,&rom$a to ! rocks & p]mit ! mon/] to dev\r h]4 ,illu/ration3 ,,novemb]--,,&rom$a ,,& ,,pegasus ,z ! /ory goes1 ! valiant h]o1 ,p]seus1 *anc$ to be rid+ ?r\gh ! air on 8 w+$ horse & saw1 f> b5ea? him ! beautiful maid5 *a9$ to ! rocks & ! frightful mon/] approa*+ to dev\r h]4 ,he imm$iately w5t to ! rescue1 &1 aft] a t]rible /ruggle ) ! mon/]1 succe$$ 9 ov]p[]+ him & ?us sav$ ! maid5 f a dreadful fate4 ,p]seus & ! fair ,&rom$a 7 m>ri$ %ortly aft]w>d1 & at ! end ( a happy life ! pair 7 transf]r$ to ! heav5s4 ,cassiopeia1 ! va9 que51 0 ord]$ to be b\nd to a *air &1 ) ! k+ ,cepheus at h] side1 to be swung cont9ually ar\nd ! nor? pole ( ! heav5s t %e might be taught a lesson 9 humility4 ,! con/ellation ,cetus1 repres5t+ ! sea-mon/]1 w be f\nd to ! s\!a/ & s\? ( ,pisces1 ,! ,fi%es1 :i* lie s\? ( ,&rom$a & ,pegasus4 ,! ,great ,squ>e 9 ,pegasus is ! mo/ conspicu\s configuration ( />s to be se5 9 ! heav5s 9 autumn ev5+s4 ,! /> t m>ks ! nor!a/]n corn] ( ,! ,great ,squ>e belongs to ! con/ellation ( ,&rom$a & m>ks ! head ( ! maid51 :o is re/+ ^u ! %\ld]s ( ,pegasus1 ,! ,w+$ ,horse4 ,! ?ree bright />s ne>ly 9 a /raight l9e outl9e ! maid5's body1 ,alpha1 or ,alph]atz1 z x is call$1 be+ ! /> 9 ! head1 ,beta or ,mira* 9 ! wai/1 & ,gamma or ,alma* 9 ! left foot4 ,! la/-nam$ />1 :i* is f>!/ to ! nor!a/ 9 ! diagram1 01 9 ! op9ion ( ! not$ a/ronom] ,h]s*el1 ! f9e/ d\ble /> 9 ! heav5s4 ,! two />s into :i* ! telescope splits x are ( ! beautifully contra/$ %ades ( orange & sea gre54 ,a second mo/ int]e/+ object 9 ,&rom$a & "o ( ! f9e/ 9 ! entire heav5s is ,! ,great ,&rom$a ,nebula1 :i* is fa9tly visible )\t ! aid ( a telescope z a hazy pat* ( light4 ,x is believ$ t 9 reality ?is nebula is a great univ]se compos$ ( _m ?\s&s ( />s s di/ant t no telescope c %[ ! individual memb]s & t ! light f x takes _m ?\s&s ( ye>s to span ! abyss t sep>ates x f ! sol> sy/em4 ,"s magnific5t photographs ( ,! ,great ,&rom$a ,nebula h be5 tak5 ) p[]ful telescopes4 ,x is ?r\gh ! use ( photography t ! nebul c be/ be /udi$1 = a photographic plate aft] long exposure1 reveals a wond]ful detail 9 ! /ructure ( ^! objects t ! human eye fails to see4 ,on a cle>1 d>k ev5+ "o may f9d ,! ,great ,&rom$a ,nebula by ! aid ( two fa9t />s ) :i* x makes a small triangle1 z %[n 9 ! *>t4 ,?is nebula is ! only "o ( ! spiral nebula t c be se5 9 ^! latitudes )\t ! aid ( a telescope1 ?\gh !re are sev]al spiral nebul 9 ! s\!rn heav5s t c be ?us se54 ,ly+ to ! nor?we/ ( ,! ,great ,squ>e 9 ,pegasus are a numb] ( fa9t />s t outl9e ! %\ld]s & head ( ! w+$ /e$1 :ile ! />s to ! s\?we/ ( ! squ>e outl9e 8 =elegs4 ,! creature is repres5t$ )\t h9d qu>t]s 9 all /> atlases4 ,! space )9 ,! ,great ,squ>e conta9s no bright />s1 & z a result1 ! outl9e ( ! squ>e /&s out ) great di/9ctness4 ,!re are1 9 fact1 no />s ( ! fir/ magnitude 9 ei!r ,pegasus or ,&rom$a1 ?\gh !re are a numb] ( ! second & ?ird magnitude :i* v cle>ly %[ ! di/9ctive =ms ( ^! two />-gr\ps4 ,pisces1 ,! ,fi%es1 ! con/ellation j s\? ( ,&rom$a & ,pegasus1 is ! fir/ ( ! twelve zodiacal con/ellations4 ,x consi/s ( ! s\!rn fi%1 ly+ 9 an ea/-to-we/ direction1 & ! nor!rn fi%1 ly+ ne>ly nor? & s\?1 ! two t\*+ at ! s\!a/]n extremity ( ! con/ellation4 ,illu/ration3 ,,novemb]--,,pisces ,!re is 9 ,pisces n a s+le bright />1 & its only po9t ( int]e/ is to be f\nd 9 ! fact t x conta9s ! po9t1 m>k$ by ! cross & lett] ,v 9 ! diagram1 t is kn[n v>i\sly z ! v]nal equ9ox1 ! equ9octial po9t & ,! ,fir/ ,po9t 9 ,aries4 ,?is is a v important po9t ( ref]5ce 9 ! heav5s1 j z ! m]idian ( ,gre5wi* is = ! e>?1 & x m>ks ! po9t :]e ! sun crosses ! equator go+ nor? 9 ! spr+4 ,ow+ to ! ,precession ( ! ,equ9oxes1 z x is call$1 ?is po9t is gradually %ift+ its position we/w>d ?r\gh ! zodiacal con/ellations at a rate t w c>ry x completely ar\nd ! heav5s ?r\gh ! twelve zodiacal gr\ps 9 a p]iod ( #be1hjj ye>s4 ,s9ce ! beg9n+ ( ! ,*ri/ian era1 ?is po9t has back$ f ! con/ellation ( ,aries1 :i* lies j ea/ ( ,pisces1 into ,pisces1 ?\gh x /ill reta9s its "n ( ,! ,fir/ ,po9t 9 ,aries4 ,,xiii ,,decemb] ,! ea/]n half ( ! sky on e>ly ,decemb] ev5+s is adorn$ ) "s ( ! f9e/ />-gr\ps 9 ! heav5s2 b z we are consid]+ = ea* mon? only ! con/ellations t lie on or ne> ! m]idian 9 ! e>ly ev5+ h\rs1 we mu/ turn our eyes = ! pres5t f ! sp>kl+ brilliants 9 ! ea/ to ! />s 9 ! less conspicu\s gr\ps ( ,aries1 ,! ,ram1 & ,cetus1 ,! ,:ale4 ,we w also become acqua9t$ ?is mon? ) ! beautiful & int]e/+ con/ellation ( ,p]seus1 ! h]o ( my?ical fame to :om we ref]r$ la/ mon? 9 connection ) ! leg5d ( ,cepheus & ,cassiopeia4 ,cetus1 y w recall1 repres5ts ! sea-mon/] s5t to dev\r ,&rom$a1 ! daught] ( ,cepheus & ,cassiopeia4 ,we h includ$ ! con/ellation ( ,&rom$a 9 our diagram = ?is mon?1 s9ce x is s closely associat$ 9 leg5d ) ! con/ellations ( ,p]seus & ,cetus1 ?\gh we also %[$ x la/ mon?4 ,! brighte/ /> 9 ,p]seus1 kn[n z ,alpha ,p]sei1 is at ! c5t] ( a curv$ l9e ( />s t is concave or holl[ t[>d ! nor!a/4 ,?is l9e ( />s is call$ ! ,segm5t ( ,p]seus1 & x lies along ! pa? ( ! ,milky ,way1 :i* passes f ?is po9t 9 a nor?we/]ly direction into ,cassiopeia4 ,accord+ to ! leg5d1 ,p]seus1 9 8 great ha/e to rescue ! maid5 f ,cetus1 ! mon/]1 /irr$ up a great du/1 :i* is repres5t$ by ! numb]less fa9t />s 9 ! ,milky ,way at ?is po9t4 ,! /> ,alpha is 9 ! mid/ ( "o ( ! f9e/ regions ( ! heav5s = ! possessor ( a good field-glass or small telescope4 ,a %ort di/ance to ! s\?we/ ( ,alpha is "o ( ! mo/ int]e/+ objects 9 ! heav5s4 ,to ! anci5ts1 x repres5t$ ! baleful1 w9k+ demon-eye 9 ! head ( ! snaky-lock$ ,gorgon1 ,m$usa1 :om ,p]seus vanqui%$ 9 "o ( 8 e>lie/ exploits & ^: head he c>ri$ 9 8 h& at ! "t ( ! rescue ( ,&rom$a4 ,to ! a/ronom]s1 h[ev]1 ,algol is kn[n z ,beta ,p]sei1 a /> t has be5 f\nd to consi/ ( two />s revolv+ ab\t ea* o!r & sep>at$ by a di/ance n mu* great] ?an _! own diamet]s4 ,"o ( ! />s is s fa9t t we speak ( x z a d>k />1 ?\gh x does emit a fa9t light4 ,once 9 e revolution ! fa9t /> passes directly betwe5 u & ! bright /> & p>tly eclipses x1 %utt+ (f five-six?s ( its light4 ,?is happ5s ) great regul>ity once 9 a little less ?an ?ree days4 ,x is = ?is reason t ,algol v>ies 9 brightness 9 ?is p]iod4 ,!re are a numb] ( />s t v>y 9 brightness 9 a simil> mann]4 ,_! p]iods ( light-*ange are all v %ort1 & ! a/ronom]s call !m eclips+ v>iables4 ,at its brighte/1 ,algol is slightly bright] ?an ! /> ne>e/ to x 9 ,&rom$a1 :i* is an excell5t /> ) :i* to comp>e x4 ,illu/ration3 ,,decemb]--,,p]seus1 ,,aries ,,& ,,cetus ,p]seus is ano!r "o ( ! con/ellations ly+ 9 ! ,milky ,way 9 :i* tempor>y />s or novas h sudd5ly fla%$ =?4 ,at ! po9t indicat$ by a cross 9 ! diagram1 ,dr4 ,&]son1 an amateur a/ronom] ( ,scotl&1 f\nd on ,febru>y #ba1 #aija1 a new /> z brilliant z ! pole-/>4 ,on ! foll[+ day x became bright] ?an a /> ( ! fir/ magnitude4 ,a day lat] x _h lo/ a ?ird ( its light1 & 9 a few weeks x 0 invisible )\t ! aid ( a telescope4 ,9 a ye> x 0 invisible 9 all except ! mo/ p[]ful telescopes4 ,) su* telescopes1 x may /ill be se5 z a v fa9t nebul\s light4 ,triangulum & ,aries are two r inconspicu\s con/ellations t lie on1 or close to1 ! m]idian at ?is "t4 ,!re is no?+ rem>kable ab\t ei!r ( ^! gr\ps1 except t ,aries is "o ( ! twelve zodiacal con/ellations4 ,"s c5turies ago1 ! sun 0 to be f\nd 9 ,aries at ! beg9n+ ( spr+ & ! position x occupies 9 ! sky at t "t 0 call$ ! ,fir/ ,po9t 9 ,aries4 ,z ?is po9t is sl[ly %ift+ we/w>d1 z we h expla9$ else:]e1 ! sun is n[ to be f\nd 9 ,pisces1 in/ead ( ,aries at ! beg9n+ ( spr+ & does n ent] ,aries until a mon? lat]4 ,pisces 0 "o ( ! con/ellations = ,novemb] & we %[$ 9 t con/ellation ! pres5t position ( ! sun at ! beg9n+ ( spr+4 ,two />s 9 ,aries--,alpha & ,beta--are fairly bright1 ,alpha be+ fully z bright z ! brighte/ /> 9 ,&rom$a4 ,beta lies a %ort di/ance to ! s\?we/ ( ,alpha1 & a little to ! s\?we/ ( ,beta is ,gamma1 ! ?ree />s =m+ a %ort curv$ l9e ( />s t di/+ui%es ?is con/ellation f o!r gr\ps4 ,! rema9+ />s 9 ,aries are all fa9t4 ,j s\? ( ,aries lies ! head ( ,cetus1 ,! ,:ale4 ,?is is an enorm\s con/ellation t ext5ds f> to ! s\?we/1 bel[ a "p ( ,pisces1 :i* runs 9 betwe5 ,&rom$a & ,cetus4 ,its brighte/ />1 ,beta1 ,diphda1 or ,d5eb ,kaitos1 z x is sev]ally call$1 /&s q alone n f> above ! s\?we/]n horizon4 ,x is almo/ due s\? ( ,alpha ,&rom$1 ! /> 9 ,&rom$a f>!/ to ! we/1 :i* x exactly equals 9 brightness4 ,! head ( ,cetus is m>k$ by a five-sid$ figure compos$ ( />s t are all fa9t ) ! s+le exception ( ,alpha1 :i* is fairly bright1 ?\gh inf]ior to ,beta or ,diphda4 ,cetus1 ?\gh made up *iefly ( fa9t />s1 & on ! :ole un9t]e/+1 conta9s "o ( ! mo/ peculi> objects 9 ! heav5s1 ! /> kn[n z ,omicron ,ceti or ,mira 7,! ,wond]ful74 ,?is /> sudd5ly rises f invisibility ne>ly to ! brightness ( a fir/-magnitude /> = a %ort p]iod once e elev5 mon?s4 ,mira 0 ! fir/ kn[n v>iable />4 ,its rem>kable p]iodic *ange 9 brightness 0 discov]$ by ,fabricius 9 ! ye> #aeif1 s its peculi> behavior has be5 "u obs]vation = ?ree hundr$ & tw5ty-five ye>s4 ,x is call$ a long-p]iod v>iable />1 because its v>iations ( light take place 9 a p]iod ( mon?s in/ead ( a few h\rs or days1 z is ! case ) />s su* z ,algol4 ,mira is n only a wond]ful />1 x is a my/]i\s /> z well1 = ! cause ( its light-*anges are n kn[n1 z 9 ! case ( ,algol :]e ! loss ( light is produc$ by a d>k /> pass+ 9 front ( a bright] />4 ,mira is a deep-r$ />1 z are all long-p]iod v>iable />s t *ange irregul>ly 9 brightness4 ,x is visible )\t a telescope = only "o mon? or six weeks out ( ! elev5 mon?s4 ,dur+ ! rema9d] ( ?is "t1 x sometimes loses s mu* ( its light t x _c be f\nd ) telescopes ( consid]able size4 ,its p]iods ( light-*ange are q v>iable z is also ! am\nt ( light x ga9s at diff]5t appe>ances4 ,x is believ$ t ! cause ( ! light-*anges ( ,mira is to be f\nd )9 ! /> itself4 ,x has be5 ?\ght t d5se cl\ds ( vapors may surr\nd ^! comp>atively cool1 r$ />s & t ! imprison$ heat f9ally bur/s ?r\gh ^! vapors & we see = a %ort "t ! gl[+ gases bel[2 !n ! vapors once m collect = a long p]iod1 to be foll[$ by ano!r sudd5 outbur/ ( heat & light4 ,x is int]e/+ to rememb] 9 ?is connection t our own sun has be5 f\nd to be slightly v>iable 9 ! am\nt ( light & heat t x gives =? at diff]5t times1 & ! cause ( its *anges 9 light & heat are believ$ to lie )9 ! sun itself4 ,,xiv ,,/>s ,,( ,,! ,,s\!rn ,,hemisph]e ,z "o travels s\?w>d f ! mid-latitudes ( ! nor!rn hemisph]e into ! tropics our famili> circumpol> con/ellations s9k l[] & l[] 9 ! nor!rn heav5s & /range & unfamili> />-gr\ps rise gradually above ! s\!rn horizon4 ,if we make our s\?w>d j\rney 9 ! w9t] mon?s ! fir/ ( ! s\!rn con/ellations to come fully into view is ! small />-gr\p j s\? ( ,lepus kn[n z ,columba 7,! ,dove71 ^: brighte/ /> ,phact is ( ! second magnitude4 ,a l9e drawn f ,procyon to ,sirius & ext5d$ z f> aga9 br+s u to ?is /> & a l9e f ,betelgeuze to ,sirius ext5d$ an equal di/ance br+s u to ,zeta ,argus :i* is equal to ,phact 9 brightness4 ,! two l9es int]sect+ at ,sirius make ! ,egyptian ,x z x is call$4 ,magnific5t1 blue-:ite ,canopus1 ! mo/ brilliant /> 9 ! heav5s next to ,sirius1 a v]itable diamond sp>kl+ l[ 9 ! s\!rn sky1 n[ comm&s our unqualifi$ admiration4 ,canopus lies ab\t #ce s\? ( ,sirius & is invisible nor? ( ! #cg? p>allel ( latitude4 ,at n9e o'clock 9 ! ev5+ ( ,febru>y #f? x c be se5 j above ! s\!rn horizon 9 t latitude & is !n a conspicu\s object 9 ,georgia1 ,florida & ! ,gulf ,/ates4 ,! /> ( ,egypt ^: pr\d light ,nev] ha? beam$ on ^? :o re/ ,9 ! ,:ite ,isl&s ( ! ,we/4 writes ,moore ( ,canopus 9 ,lalla ,rookh4 ,along ! ,nile ,canopus 0 an object ( wor%ip z ! god ( wat]s4 ,at ! "t ( _! erection1 #fdjj ,b4,c41 a numb] ( temples 9 ,upp] ,egypt 7 ori5t$ s z to %[ ,canopus at sunrise at ! autumnal equ9ox1 & o!r temples erect$ _m c5turies lat] 7 ori5t$ 9 a simil> mann]4 ,9 ,*9a1 z late z #ajj ,b4,c41 & 9 ,india also ,canopus 0 an object ( wor%ip4 ,! a/ronom] tells u t ,canopus is immeasurably di/ant f ! e>?4 ,x has be5 e/imat$ to be =ty ?\s& times m lum9\s ?an our sun4 ,canopus is locat$ 9 ! con/ellation ( ,argo ,navis :i* is ! l>ge/ & mo/ conspicu\s con/ellation 9 ! heav5s4 ,9 addition to ,canopus x conta9s a numb] ( second- & ?ird-magnitude />s & is subdivid$ = conv5i5ce into ,puppis1 ,! ,pr[2 ,c>9a1 ,! ,keel2 & ,vela1 ,! ,sails4 ,huge z x is1 ,argo ,navis repres5ts only half ( a %ip = ! /]n is lack+4 ,accord+ to ! leg5d ?is %ip 0 built by ,argos1 aid$ by ,pallas ,a!ne1 = ,jason1 ! lead] ( ! exp$ition ( ! fifty ,argonauts :o sail$ f ,greece to ,col*is 9 se>* ( ! gold5 fleece4 ,pallas ,a!ne plac$ 9 ! b[ ( ! %ip a piece ( timb] f ! speak+ oak ( ,dodona to guide ! crew & w>n !m ( dang]s & aft] ! voyage ! %ip 0 suppos$ to h be5 plac$ 9 ! heav5s4 ,illu/ration3 ,,s\!rn ,,con/ellations--#a4 ,,9 ,,febru>y ,9 ,argo ,navis is "o ( ! f9e/ telescopic objects 9 ! heav5s1 ! ,keyhole ,nebula1 z x is usually call$1 f a peculi>-%ap$ d>k pat* 9 its brighte/ "p4 ,on ! bord] ( ?is nebula is ! deep-r$ ,wond] ,/> ( ! s\!rn hemisph]e1 ,eta ,argus1 :i* v>ies sudd5ly & unexpect$ly 9 brightness betwe5 ! sev5? & fir/ magnitudes4 ,9 #ahdc x bur/ =? ) a spl5dor rival+ ,sirius & ma9ta9$ ?is brilliancy = ne>ly t5 ye>s & !n sl[ly wan$ 9 brilliancy until x disappe>$ to ! unaid$ eye 9 #ahhf4 ,! surr\nd+ nebula also seems to %>e 9 its peculi> fluctuations ( brightness4 ,eta ,argus is n[ a /> ( ! sev5? magnitude & s9ce x is /ill v>y+ fitfully 9 brightness x is believ$ t ! hi/ory ( its light-*anges is n complete4 ,among ! con/ellations ( ! s\!rn heav5s ne> ! m]idian 9 ,febru>y we see 9 addition to ,argo ,navis ! con/ellations ( ,dorado1 ,! ,goldfi%2 ,hydrus1 ,! ,s]p5t1 & ,tucana1 ,! ,t\can4 ,?\gh insignificant 9 appe>ance ,dorado conta9s :at 0 describ$ by ,sir ,john ,h]s*el z "o ( ! mo/ extraord9>y objects 9 ! heav5s1 a wor?y rival ( ,! ,great ,orion ,nebula & 9 "s respects v simil> to x1 ,! ,great ,loop$ ,nebula1 ! c5t] ( a great spiral4 ,9 ,dorado also is locat$ ,! ,great] ,magellanic ,cl\d :i* looks l a deta*$ portion ( ! ,milky ,way ?\gh x is f> remov$ f x4 ,to ! nak$ eye x resembles a small :ite cl\d ab\t #d 9 ext5t4 ,9 ! telescope x be>s a close resemblance to a typical portion ( ! ,milky ,way4 ,a simil> =mation kn[n z ,! ,less] ,magellanic ,cl\d is locat$ 9 ,hydrus4 ,x has be5 e/imat$ t ! di/ance ( ,! ,less] ,cl\d is #hj1jjj light-ye>s & t x is rec$+ f u4 ,9 ,tucana is locat$ "o ( ! f9e/ globul> /> clu/]s 9 ! heav5s1 kn[n z #dg ,tucan4 ,?is clu/] & ,omega ,c5tauri1 a globul> /> clu/] 9 ,c5taurus1 are ! two ne>e/ ( all ! globul> clu/]s4 ,!y are di/ant f ! e>? ab\t #bb1jjj light-ye>s & x is kn[n t ! comb9$ light ( ! ?\s&s ( />s ( :i* ea* clu/] is compos$ is ab\t "o million times t ( our own sun4 ,9 ! we/]n sky 9 ! s\!rn hemisph]e 9 ,febru>y may be se5 ! brilliant1 :ite1 fir/-magnitude /> ,a*]n> 9 ! riv] ,eridanus1 ! long1 w9d+ con/ellation t1 we recall1 />ts ne> ! brilliant ,rigel 9 ,orion & disappe>s f ! view ( nor!rn obs]v]s bel[ ! s\!rn horizon1 ext5d+ its c\rse f> into ! s\!rn hemisph]e4 ,a*]n> means ,! ,end ( ! ,riv] & ?is is ne>ly its position 9 ! con/ellation4 ,?\gh ,argo ,navis is ! l>ge/ & mo/ important con/ellation ( ! s\!rn hemisph]e1 ,crux1 ,! ,s\!rn ,cross1 f>-fam$ 9 /ory & leg5d z well z = its hi/orical associations1 is beyond a d\bt ! mo/ popul>4 ,! be/ "t to view ! ,s\!rn ,cross is 9 ,june or ,july :5 x is ne> ! m]idian4 ,x is n se5 to advantage 9 ! mon?s ( ,janu>y or ,febru>y4 ,x !n lies on its side & close to ! horizon & !re=e is dimm$ by atmosph]ic haze s t x almo/ inv>iably is a disappo9t+ object to ! t\ri/ f ! nor? :o usually views x = ! fir/ "t 9 "o ( ^! mon?s4 ,! ,cross is view$ to advantage 9 ! latitude ( ,rio or ,valp>aiso & x is be/ se5 f ! ,/raits :]e x rides high ov]head4 ,x is n se5 to advantage f ! latitudes ( ,cuba or ,jamaica4 ,x is small1 only #f 9 ext5t f nor? to s\? & less 9 wid? & x lies 9 ! mo/ brilliant portion ( ! ,milky ,way :i* is "h a n>r[ /ream only ?ree or f\r degrees wide4 ,directly bel[ ! ,cross is ! not$ ,coal ,sack1 app>5tly a yawn+ *asm 9 ! mid/ ( its brilliant surr\nd+s ?\gh probably 9 reality a d>k nebula4 ,view$ ) ! telescopes a numb] ( />s are to be se5 project$ on ?is d>k backgr\nd4 ,! ,s\!rn ,cross is to ! inhabitants ( ! s\!rn hemisph]e :at ! ,big ,dipp] is to ^? :o dwell 9 ! nor!rn hemisph]e--an infallible timepiece4 ,! upright ( ! ,cross po9ts t[>d ! s\? pole ( ! heav5s :i* lies 9 a region :]e !re is a s+ul> de>? ( bright />s1 ! ne>e/ /> to ! s\? pole be+ a fa9t fif?-magnitude /> call$ ,sigma ,octantis4 ,:5 se5 9 ! s\!a/ or s\?we/ ! ,cross lies on its side1 b :5 pass+ ! m]idian x /&s ne>ly upright4 ,humboldt1 ref]r+ to ?is fact1 says3 ,h[ (t5 h we he>d our guides exclaim 9 ! savannahs ( ,v5ezuela & 9 ! des]t ext5d+ f ,lima to ,truxillo1 ',midnight is pa/1 ! ,cross beg9s to b5d4' ,by ! explor]s ( ! sixte5? c5tury ! ,cross 0 tak5 z a sign ( heav5's approval ( _! attempt to e/abli% ! ,*ri/ian religion 9 ! wilds ( ! ,new ,_w4 ,?is ?\ght is beautifully express$ 9 ,mrs4 ,hemans' l9es 9 ,! ,cross ( ! ,s\?4 ,b to !e1 z ?y lode-/>s respl5d5tly burn ,9 _! cle> dep?s ( blue1 ) devotion ,i turn ,bright ,cross ( ! ,s\?6 & behold+ !e %9e1 ,sc>ce regret ! lov$ l& ( ! olive & v9e4 ,?\ recalle/ ! ages :5 fir/ o'er ! ma9 ,my fa!rs unfold$ ! ensign ( ,spa91 ,& plant$ _! fai? 9 ! regions t see ,its imp]i%+ symbol ev] blazon$ 9 !e4 ,alpha ,crucis1 ! brighte/ /> 9 ,crux1 is at ! foot ( ! ,cross4 ,x consi/s 9 reality ( two second-magnitude />s =m+ a beautiful d\ble :ile a ?ird fif?-magnitude /> "o & "o-half m9utes ( arc di/ant makes ) ?is pair a comb9ation simil> to our ,miz> & ,alcor ( ! ,big ,dipp] ?\gh ! sep>ation is n great en\gh to be visible to ! nak$ eye4 ,! second-magnitude /> at ! head ( ! ,cross is a deep orange 9 color & ! two />s t m>k ! ends ( ! cross-arm are :ite ?ird-magnitude />s4 ,illu/ration3 ,,s\!rn ,,con/ellations--#b4 ,,9 ,,july ,"o ( ! f9e/ con/ellations ( ! s\!rn hemisph]e is ,c5taurus1 ,! ,c5taur1 :i* surr\nds ,crux on ! nor? & is m ?an #fj 9 l5g?4 ,its c5t] lies ab\t #ej s\? ( ,spica 9 ,virgo & bel[ ! tail ( ,hydra4 ,alpha ,c5tauri1 its brighte/ /> & ! ne>e/ /> to ! sol> sy/em1 f\r & "o-?ird light-ye>s away1 is a gold5-yell[ d\ble /> t =ms ) ! /> ,beta ,c5tauri on ! we/ a configuration simil> to t ( ,ca/or & ,pollux 9 ,gem9i1 only "o t is f> m /rik+ because ( ! sup]ior brilliancy ( ! />s4 ,alpha ,c5tauri lies 9 ! ,milky ,way & transits ! m]idian at ! same "t ) ,arcturus ?\gh x _c be se5 nor? ( ! #bi? p>allel4 ,alpha ,c5tauri1 l ,canopus1 0 an object ( wor%ip 9 ,egypt & a numb] ( temples 9 nor!rn ,egypt 7 ori5t$ to its em]g5ce f ! sun's rays 9 ! morn+ at ! autumnal equ9ox1 betwe5 #cjjj & #bege ,b4,c4 ,nor? ( ,c5taurus is ! con/ellation ,lupus1 ,! ,wolf1 :i* is also cross$ by ! ,milky ,way4 ,accord+ to "o my? ,lupus is held 9 ! "r h& ( ! ,c5taur z an (f]+ ^u ! alt> :i* is repres5t$ by ! con/ellation ( ,ara next to ,c5taurus on ! ea/4 ,ara also is cross$ by ! ,milky ,way4 ,nei!r ,lupus nor ,ara conta9 any objects t are wor?y ( special att5tion4 ,triangulum ,au/rale1 ,! ,s\!rn ,triangle1 a little to ! s\!a/ ( ,alpha ,c5tauri1 is f> m conspicu\s ?an ! ,triangulum ( ! nor!rn hemisph]e4 ,! accompany+ *>ts give two views ( ^! pr9cipal s\!rn con/ellations t lie )9 #dj ( ! s\? pole ( ! heav5s & t are bel[ ! horizon 9 #dj nor? latitude4 ,! fir/ ( ^! *>ts %[s ! con/ellations t are ne>e/ ! m]idian 9 ! e>ly ev5+ h\rs 9 ,febru>y4 ,canopus 9 ,argo ,navis & ! ,great] ,magellanic ,cl\d !n lie close to ! m]idian4 ,argo ,navis ) its subdivisions ,puppis1 ,vela & ,c>9a are f\nd ea/ ( ! m]idian ly+ directly 9 ! pa? ( ! ,milky ,way1 :i* /ret*es diagonally across ! sky f ! nor?we/ to ! s\!a/4 ,f> ov] 9 ! s\!a/ appe>s ,crux1 ! ,s\!rn ,cross1 also directly 9 ! pa? ( ! ,milky ,way4 ,9 ! we/]n heav5s may be se5 ! ,less] ,magellanic ,cl\d 9 ,hydrus1 brilliant ,a*]n> 9 ,eridanus & ! inconspicu\s />-gr\p ( ,tucana4 ,9 ! e>ly ev5+ h\rs ( ,july we f9d z %[n on ! second *>t1 ,alpha & ,beta ,c5tauri 9 ,c5taurus close to ! m]idian1 ,lupus due nor? ( ,c5taurus1 ,ara & ,triangulum ,au/rale 9 ! s\!a/ & ,crux 9 f9e position = obs]vation j we/ ( ! m]idian4 ,c>9a ( ,argo ,navis lies to ! s\?we/ ( ,crux4 ,! ,milky ,way n[ ar*es magnific5tly across ! heav5s f ,c>9a ?r\gh ,crux1 ,c5taurus & ,lupus & ,ara to ! zodiacal gr\ps ( ,scorpio & ,sagitt>ius 9 ! nor!a/4 ,9 ! nor!rn "p ( ! heav5s1 z se5 f ! s\!rn hemisph]e1 appe> ! famili> zodiacal con/ellations t we ( ! nor!rn hemisph]e f9d s\? ( ! z5i?1 z well z ! con/ellations ( ,orion1 ,lepus & ,canis ,major1 ,hydra1 ,corvus & ,crat]1 ,ophiu*us & ,s]p5s & ,aquila1 all f9ely 9 view 9 _! appropriate seasons4 ,x is only our famili> circumpol> con/ellations ( ! nor?--,! ,two ,be>s1 ,draco1 ,cassiopeia1 & ,cepheus1 ,&rom$a & ,p]seus & ,auriga t are invisible 9 mid-latitudes ( ! s\!rn hemisph]e j z ! con/ellations %[n 9 ! diagrams1 & a few additional gr\ps su* z ,pavo1 ,grus1 ,pho5ix1 ,apus1 ,m5sa & ,volans :i* we h n %[n1 lie hidd5 f view b5ea? ! s\!rn horizon 9 mid-latitudes ( ! nor!rn hemisph]e4 ,! nor!rn visitor to ! s\!rn hemisph]e famili> ) ! con/ellations ( 8 own l& is fill$ ) a que] s5sation ( be+ 9 topsy-turvydom z he sees famili> ,orion /&+ on 8 head & all ( ! zodiacal con/ellations pass+ 9 _! daily motions to ! nor? in/ead ( to ! s\? ( 8 z5i? :ile by day ! sun passes across ! nor!rn "p ( ! heav5s & culm9ates nor? in/ead ( s\? ( 8 z5i?4 ,he misses ! famili> ,dipp]s ( 8 own l& & se>*es 9 va9 = a pole-/> 9 ! unfamili> circumpol> regions ( ! s\?4 ,,xv ,,! ,,milky ,,way ,,or ,,galaxy ,broad & ample road ^: du/ is gold1 ,& pavem5t />s1 z />s to !e appe> ,se5 9 ! galaxy1 t milky way ,:i* nightly z a circl+ zone ?\ see/ ,p[d]'d ) />s4 --,,milton1 ,p>adise ,lo/4 ,on cle>1 w9t] ev5+s "o may see a portion ( ! zone ( ! ,milky ,way1 :i* encircles ! heav5s1 ar*+ magnific5tly across ! heav5s z x passes f ,cassiopeia & ,cepheus 9 ! nor?we/1 ?r\gh ,p]seus & ,auriga & ! ea/]n "p ( ,taurus1 across ! feet ( ,gem9i1 betwe5 ,canis ,m9or & ,orion & ?r\gh ! ea/]n "p ( ,canis ,major to ! s\!rn horizon4 ,at ?is po9t x passes beyond our range ( vision into ! />-gr\ps ( ,puppis1 ,vela & ,c>9a1 subdivisions ( ! huge s\!rn con/ellation ( ,argo ,navis4 ,x rea*es its greate/ di/ance s\? ( ! cele/ial equator & also atta9s its greate/ brilliancy 9 ,crux1 ! f>-fam$ ,s\!rn ,cross4 ,f "h x turns nor?w>d once m1 pass+ into ,c5taurus1 ,musca1 ,circ9us ,ara & ,lupus con/ellations ( ! s\!rn hemisph]e & comes )9 our range ( vision aga9 9 ,sagitt>ius & ,scorpio4 ,"h ! ,milky ,way divides into two bran*es1 ?\gh "s a/ronom]s n[ believe t ?is app>5t division into two bran*es is due to ! pres5ce ( an enorm\s cl\d ( non-lum9\s matt] ly+ along ! c\rse ( ! ,milky ,way at ?is po9t1 simil> 9 its nature to ! d>k holes & caves & /reaks t appe> 9 all portions ( ! ,milky ,way & mo/ noticeably a?w>t its c\rse 9 ,argo & ,c5taurus4 ,"o ( ^! bran*es ( ! ,milky ,way passes f ,sagitt>ius ?r\gh ,aquila to ,cygnus & ! o!r ?r\gh ,scorpio1 ,ophiu*us & ,s]p5s to ,cygnus1 ! two ext5d+ diagonally across ! heav5s 9 ! late summ] & e>ly fall ev5+s f ! nor!a/ to ! s\?we/4 ,f ,cygnus1 ! ,milky ,way passes into ,cepheus & ,cassiopeia & ?us completes its circuit ( ! heav5s4 ,x is n se5 to advantage 9 spr+ or e>ly summ] ev5+s because x !n re/s ne>ly on ! horizon4 ,its plane is incl9$ ab\t #fc to ! cele/ial equator & its poles lie 9 ! con/ellations ( ,coma ,b]5icis & ,cetus4 ,^! are ! two po9ts t lie f>!/ f ! ,milky ,way4 ,! ,milky ,way has be5 call$ ! gr\ndwork ( ! univ]se4 ,by f> ! great] numb] ( all ! />s are cr[d$ t[>ds its plane 9 ! =m ( an enorm\s flatt5$ disk or l5s4 ,our sol> sy/em1 x has be5 e/imat$1 lies close to ! plane ( ! ,milky ,way & at a di/ance ( "s #ej1jjj or #fj1jjj light-ye>s f its c5t]4 ,! diamet] ( ! ,milky ,way z d$uc$ f ,dr4 ,h>l[ ,%apley's "w on globul> /> clu/]s is ab\t #cjj1jjj light-ye>s 9 ext5t1 or t5 times great] ?an ! limit set "s ye>s ago4 ,! app>5t cr[d+ toge!r ( ! />s into d5se cl\ds 9 ! ,milky ,way is p>tly an effect due to our position 9 ! ,milky ,way4 ,:5 we look at ! heav5s 9 a direction at "r angles to ?is plane we f9d comp>atively few />s ly+ along our l9e ( vision because ! />s are actually few] 9 numb] 9 ?is direction4 ,if we look along ! plane ( ! ,milky ,way1 h[ev]1 we see to a great] di/ance ?r\gh an enorm\s dep? ( />s4 ,?\gh individual />s may n be mu* clos] toge!r 9 ! ,milky ,way ?an !y are outside ( x1 !re are on ! :ole m ( !m & ! effect ( great] d5sity is produc$4 ,fa!r ,hag5 ( ! ,vatican ,obs]vatory1 :o has = ye>s made a /udy ( ! d>k cl\ds ( obscur+ matt] & d>k nebul t ab\nd 9 space1 has f\nd evid5ce ( ! exi/5ce ( _m va/ cl\ds ( d>k obscur+ matt] ov] ! entire heav5s above & bel[ ! plane ( ! ,milky ,way z well z surr\nd+ ! ,milky ,way 9 its own plane4 ,! exi/5ce ( su* cl\ds ( non-lum9\s matt] w\ld acc\nt p>tly = ! comp>ative fewness ( />s 9 space outside ( ! plane ( ! ,milky ,way s9ce _m />s w\ld be conceal$ f our eyes by ^! obscur+ cl\ds4 ,!re is1 h[ev]1 9 addition1 an actual cr[d+ ( all ! visible />s t[>d ?is plane4 ,! peoples ( all ages h honor$ ! ,milky ,way 9 /ory & leg5d4 ,x has be5 univ]sally ref]r$ to z ,! ,sky ,riv] & ,! ,pa?way ( ,s\ls4 ,to ! little ,hiawa?a1 we rememb]1 ! wr9kl$ old ,nakomis ,%[$ ! broad :ite road 9 heav5 ,pa?way ( ! gho/s1 ! %ad[s1 ,runn+ /raight across ! heav5s1 ,cr[d$ ) ! gho/s1 ! %ad[s4 ,to ! ,k+dom ( ,ponemah ,to ! l& ( ! h]eaft]4 ,9 ,! ,galaxy1 ,longfell[ ?us describes ! ,milky ,way3 ,torr5t ( light & riv] ( ! air ,along ^: b$ ! glimm]+ />s are se5 ,l gold & silv] s&s 9 "s rav9e ,:]e m\nta9 /reams h left _! *annels b>e6 ,9 ,sw$51 :]e ! ,milky ,way ar*es high ?r\gh ! z5i? 9 w9t]1 x is call$ ! ,w9t] ,/reet1 & ,miss ,edi? ,?omas writes ?us beautifully ( x 9 h] poem entitl$1 ,! ,w9t] ,/reet3 ,sil5t ) /> du/1 yond] x lies-- ,! ,w9t] ,/reet1 s fair & s :ite2 ,w9d+ along ?r\gh ! b\ndless skies1 ,d[n heav5ly vale1 up heav5ly height4 ,fa9tly x gleams1 l a summ] road ,:5 ! light 9 ! we/ is s9k+ l[1 ,sil5t ) /> du/6 ,by ^: abode ,does ! ,w9t] ,/reet 9 its w9d+s g8 ,& :o are !y1 all unhe>d & unse5-- ,o :o are !y1 ^: blessd feet ,pass ov] t highway smoo? & %e58 ,:at pilgrims travel ! ,w9t] ,/reet8 ,are !y n ^? :om "h we miss ,9 ! ways & ! days t are vacant bel[8 ,z ! du/ ( t ,/reet _! footfalls kiss ,does x n bright] & bright] gr[8 ,beautiful inde$ are ^! poetic fancies b none ( !m picture ev5 remotely ! awe-inspir+ gr&eur ( ! ,milky ,way z x actually exi/s4 ,illu/ration3 ,a ,,d>k ,,nebula3 ,,! ,,d>k ,,bay ,,or ,,d>k ,,horse ,,nebula ,,9 ,,orion ,tak5 ) #ajj-;in* ,hook] ,telescope ( ! ,mt4 ,wilson ,obs]vatory ,millions ^u millions ( f> di/ant suns equal to or surpass+ our own sun 9 brilliancy are ga!r$ )9 ?is va/ encircl+ zone ( ! heav5s1 _! comb9$ light giv+ to ! nak$ eye ! impression ( a milky b& ( light4 ,n9e-t5?s ( all ! />s1 x has be5 e/imat$1 lie close to ! plane ( ! ,galaxy1 z well z all ! va/ expanses ( lum9\s gase\s nebul & cl\ds ( d>k obscur+ matt] all seem+ly int]m+l$ 9 *aotic confusion2 yet law & ord] gov]n ! motions ( all4 ,"h also are ! great mov+ /> clu/]s su* z ! ,pleiades & ! ,hyades & all ( ! brilliant ,orion />s4 ,! /ructure ( ! ,milky ,way is n cle>ly und]/ood b _m a/ronom]s believe !re is evid5ce t x takes ! =m ( a va/ spiral nebula along ^: arms ! />s pass to & fro4 ,beyond ! ,milky ,way at enorm\s di/ances ( _m ?\s&s ( light-ye>s1 b app>5tly influ5c$ by x1 lie ! globul> />-clu/]s & ! spiral nebul4 ,! spirals appe> to avoid ! plane ( ! ,milky ,way = !y are rec$+ 9 ! direction ( its poles at high velocities2 ! globul> clu/]s on ! o!r h& are draw+ 9 t[>d ! ,milky ,way on ei!r side1 & 9 "t w cross x4 ,:e!r ^! objects ext]nal to ! ,milky ,way =m ) x "o enorm\s univ]se or :e!r ! spiral nebul are 9 turn galaxies or isl& univ]ses1 z ! a/ronom] calls !m1 simil> 9 =m & /ructure to our own galaxy & at inconceivably great di/ances ( millions ( light-ye>s f x1 is /ill "o ( ! riddles ( ! univ]se :i* ! a/ronom]s are attempt+ to solve4 ,,xvi ,,! ,,surface ,,( ,,! ,,sun ,! visible surface ( ! sun is call$ ! photosph]e4 ,ev5 ! smalle/ telescopes w %[ its peculi> rice-gra9 /ructure1 consi/+ ( int5sely brilliant flecks or nodules ab\t #ejj miles 9 diamet]1 :i* c be resolv$ by ! m p[]ful telescopes into small] p>ticles ab\t #ajj miles 9 diamet]1 aga9/ a d>k] backgr\nd4 ,x has be5 e/imat$ t ^! bright nodules or rice-gra9s occupy only "o-fif? ( ! total surface ( ! sun1 yet radiate ?ree-f\r?s ( ! total light4 ,x is g5]ally believ$ t ! rice gra9s are ! summits ( highly heat$ columns ( gas1 aris+ f ! sun's int]ior1 & t ! d>k] portions betwe5 are cool] desc5d+ curr5ts4 ,x is well kn[n t ! photosph]e or visible surface ( ! sun appe>s to be mu* bright] 9 ! c5t] ( ! disk ?an ne> its circumf]5ce4 ,?is is due entirely to its gase\s nature & to ! fact t x is surr\nd$ by an atmosph]e ( d5se envelop+ cool] gases4 ,rays f ! c5t] ( ! disk travel a %ort] di/ance ?r\gh ?is atmosph]e ?an ! rays f ! rim & !re=e are absorb$ less by surr\nd+ gases4 ,we look fur!r d[n into ! sun's int]ior ne> ! c5t] ( ! disk ?an 9 ! direction ( its circumf]5ce & s ! light appe>s m int5se !re4 ,! photosph]e is ! region :]e sun-spots appe> & !y are f\nd 9 zones ext5d+ f #h to #ce on ei!r side ( ! sol> equator1 nev] appe>+ exactly at ! equator or ne> ! poles4 ,! di/urbances t produce sun-spots & _m alli$ ph5om5a occur cyclically 9 p]iods ( elev5 ye>s on ! av]age4 ,! fir/ outbur/ ( ! di/urbance is manife/$ by ! appe>ance ( sun-spots 9 high sol> latitudes4 ,^! break out & disappe> & break out aga9 ) increas$ vigor1 work+ gradually d[nw>d t[>d ! sol> equator1 ! maximum spott$ness = a giv5 p]iod occurr+ 9 sol> latitude ab\t #af4 ,! di/urbance f9ally dies out )9 #h or #aj ( ! equator1 b ev5 be=e "o cycle ( di/urbance has entirely pass$ away a new cycle has brok5 =? 9 high latitudes4 ,s dur+ ! p]iod ( m9imum spott$ness !re are f\r di/9ct belts1 two 9 l[ latitudes1 due to ! dy+ di/urbance1 & two 9 high latitudes1 due to ! new di/urbance4 ,at sun-spot maximums !re are two well-m>k$ zones ( great int5sity1 approximately #af nor? & s\? ( ! sun's equator4 ,sun-spots are sol> cyclones1 occurr+ usually 9 gr\ps1 ?\gh l>ge s+le spots appe> less frequ5tly4 ,ea* spot is q %>ply divid$ into an umbra & a p5umbra4 ,! umbra is ! d>k] c5tral portion1 ! funnel ( ! :irl+ cyclone1 & ! p5umbra is compos$ ( ! outspread+ gases1 & is less d>k ?an ! umbra4 ,! peculi> ?at*-/raw /ructure ( ! p5umbra is due1 x is believ$1 to ! fact t ! columns ( gases t usually rise v]tically f ! sun's int]ior & f ! rice gra9s ( ! photosph]e are drawn into a horizontal position by ! :irl+ motion t exi/s 9 ! p5umbra regions ( a sun-spot & !re=e we get a longitud9al r ?an a cross sectional view ( !m4 ,! umbra ( a sun-spot is any:]e f a few hundr$ miles to fifty ?\s& miles 9 diamet]1 frequ5tly exce$+ ! e>? 9 size1 :ile ! p5umbra occasionally rea*es a diamet] ( two hundr$ ?\s& miles4 ,sun-spots ( exceptional size c be se5 ev5 )\t ! aid ( a telescope4 ,! d>kness ( sun-spots is only by comp>ison ) _! m brilliant backgr\nd4 ,ow+ to ! rapid expansion & cool+ ( gases ! temp]ature 9 sun-spot regions is f> bel[ ! normal sol> temp]ature ( #f1jjj ,c5tigrade1 ly+ betwe5 #c1jjj & #d1jjj ,c5tigrade4 ,at ?is temp]ature x is possible = ! m refractory *emical comp\nds to =m1 ! oxides & ! hydrides1 & ! spectra ( sun-spots reveal ! pres5ce ( titanium oxide & magnesium & calcium hydride4 ,at ! high] sol> temp]atures t exi/ else:]e 9 ! photosph]e & 9 its ov]ly+ gase\s envelopes all *emical elem5ts occur 9 a free /ate1 int]m+l+ z inc&esc5t vapors )\t ! =mation ( any *emical comp\nds4 ,/rong magnetic fields exi/ 9 sun-spot regions & magnetic /orms 9 our own atmosph]e frequ5tly accompany ! appe>ance ( exceptionally l>ge sun-spots4 ,directly above ! photosph]e ( ! sun lies ! rev]s+ lay]1 :i* is ab\t five hundr$ miles 9 dep? & is compos$ ( ! inc&esc5t vapors ( all ! *emical elem5ts t exi/ on ! sun1 :i* are also ! same famili> elem5ts t exi/ on ! e>?1 ) ! exception ( coronium1 ! unkn[n elem5t 9 ! sol> corona1 !re is no elem5t 9 ! sun t has n be5 f\nd on our own planet4 ,! rev]s+ lay] receives its "n f ! fact t x rev]ses ! sol> spectrum4 ,x produces by its absorption ( ! rays ( light f gases bel[ ! d>k absorption l9es f\nd 9 ! spectrum t s]ve to id5tify all ! elem5ts exi/+ 9 ! sun4 ,dur+ ! "t imm$iately prec$+ & foll[+ a total eclipse ( ! sun ?is rev]s+ lay] produces :at is kn[n z ! fla% spectrum4 ,:5 ! photosph]e1 :i* gives ! bright cont9u\s backgr\nd ( ! sol> spectrum1 is conceal$ by ! moon1 ! normally d>k l9es ( ! rev]s+ lay]--d>k only by contra/ ) ! bright backgr\nd--become mom5t>ily int5sely bright l9es aga9/ a d>k backgr\nd4 ,! fla% spectrum only la/s a second or s1 z ! rev]s+ lay] itself is soon cov]$ by ! moon4 ,j above ! rev]s+ lay] lies ! *romosph]e1 :i* is betwe5 five ?\s& & t5 ?\s& miles 9 dep?4 ,_m ( ! gase\s vapors ( ! rev]s+ lay] are f\nd 9 ! *romosph]e1 ?r[n !re cont9ually by ! va/ upheavals ( gases t are con/antly di/urb+ ! surface ( ! sun4 ,! great] ! sol> activity ! m is ! *romosph]e *>g$ ) ! vapors ( ! l[] /rata ( ! sun's atmosph]e4 ,! gases t are mo/ *>act]i/ic ( ! *romosph]e1 h[ev]1 are ! inc&esc5t gases ( hydrog5 & calcium1 :i* give x ! p9k or r$di% t+e s noticeable dur+ total sol> eclipse4 ,helium is also f\nd 9 great abundance 9 ! sol> *romosph]e4 ,%oot+ upw>d f ! photosph]e ) ! trem5d\s velocity ( "o hundr$ or m miles p] second1 c be se5 at all times1 by prop]ly scre5+ (f ! light f ! photosph]e1 ! va/ sol> eruptions kn[n z ! prom95ces4 ,^! are compos$ *iefly ( hydrog5 & calcium gas1 ?\gh o!r elem5ts also appe>1 especially ne> ! bases ( ! prom95ces4 ,prom95ces are ( two v>ieties1 ! quiesc5t1 or cl\d-l prom95ces1 t float high above ! sol> surface = days at a "t 9 "s in/ances & resemble t]re/rial cl\ds 9 =m1 & ! eruptive1 or metallic prom95ces1 t d>t up f ! surface ( ! sun 9 an inf9ite v>iety ( =ms t may be entirely *ang$ 9 ! %ort int]val ( fifte5 or tw5ty m9utes4 ,^! eruptive prom95ces usually atta9 heights ( ?irty or =ty ?\s& miles on ! av]age1 b exceptional prom95ces rea* heights ( m ?an "o hundr$ ?\s& miles & 9 a few r>e cases h rea*$ elevations ( ov] five hundr$ ?\s& miles1 or m ?an "o-half ( ! sol> diamet]4 ,prom95ces are ! mo/ spectacul> & beautiful ( all sol> ph5om5a1 ) ! possible exception ( ! sol> corona1 :i* is ! out]mo/ ( all ! sol> envelopes & also ! mo/ t5u\s4 ,! ext5t ( ! corona is enorm\s4 ,its out] /ream]s ext5d usually to di/ances ( sev]al million miles f ! c5t] ( ! sun4 ,measurem5ts ( ! coronal light dur+ total eclipses ( ! sun h %[n t its int5sity is only ab\t "o-half t ( full moonlight1 & x seems almo/ impossible to devise me?ods = detect+ x1 except dur+ total eclipses1 on acc\nt ( ! extreme fa9tness ( its light4 ,! sun1 x is n[ kn[n1 is surr\nd$ by a /rong magnetic field 9 addition to ! magnetic fields t exi/ 9 sun-spots4 ,! cycle ( sun-spot *ange is att5d$ by m>k$ *anges 9 _m =ms ( sol> activity4 ,! frequ5cy ( outbur/s ( eruptive prom95ces1 ! brightness & =m ( ! corona1 magnetic /orms & wea!r *anges on ! e>? are all closely associat$ ) ! sun-spot cycle4 ,! cause ( ?is sun-spot cycle1 ) all ! att5dant *anges 9 ! g5]al sol> activity1 & ! s\rce ( ! app>5tly limitless supply ( sol> en]gy /ill rema9 ! two *ief unsolv$ secrets ( ! sun4 ,,xvii ,,! ,,sol> ,,sy/em ,our sun is b a /> travel+ ?r\gh ! univ]se4 ,x is accompani$ 9 its j\rney to unkn[n p>ts ( space1 t lie 9 ! g5]al direction ( ! con/ellation ,h]cules1 by an ext5sive family ( m9or bodies consi/+ ( ! eight planets & _! encircl+ moons1 "o ?\s& or m a/]oids1 num]\s comets1 & meteors )\t numb]1 all mov+ 9 prescrib$ pa?s ar\nd _! rul]4 ,! mo/ important memb]s ( ! sun's family are ! planets1 ,m]cury1 ,v5us1 ,e>?1 ,m>s1 ,jupit]1 ,saturn1 ,uranus & ,neptune1 nam$ 9 ! ord] ( _! position outw>d f ! sun4 ,we he> occasionally ( ! possibility ( ! exi/5ce ( intra-,m]curial & trans-,neptunian planets & x is possible t "s day an additional planet may be discov]$ )9 ! orbit ( ,m]cury or beyond ! orbit ( ,neptune4 ,! gravitational control ( ! sun ext5ds f> beyond ! orbit ( ,neptune & !re are reasons = believ+ 9 ! exi/5ce ( at lea/ "o or two additional planets on ! outskirts ( ! sol> sy/em4 ,! exi/5ce ( a planet )9 ! orbit ( ,m]cury is n[1 aft] long cont9u$ & dilig5t se>*1 believ$ to be v d\btful4 ,7 x possible to view ! sun f ! di/ance ( ! ne>e/ /> ) ! aid ( ! greate/ telescope on e>? all ! memb]s ( 8 family w\ld be hopelessly invisible4 ,s1 also1 we _c tell z we po9t our p[]ful telescopes at ! />s :e!r ^! o!r suns are att5d$ by planet families4 ,we may only argue t x is v unlikely t !re %\ld be only "o /> among hundr$s ( millions t is att5d$ by a gr\p ( comp>atively small d>k bodies t %9e by ! reflect$ light f ! /> !y encircle4 ,) ! exception ( ! two planets1 ,m]cury & ,v5us1 :i* are kn[n z ! inf]ior planets1 s9ce _! pa?s lie betwe5 ! e>? & ! sun1 all ! planets h moons or satellites ( _! own t encircle ! planet j z ! planet encircles ! sun4 ,our planet e>? has "o satellite1 ! moon1 t has ! di/9ction ( be+ ! l>ge/ ( all ! moons 9 proportion to ! size ( ! planet x encircles4 ,jupit] & ,saturn h moons t surpass our moon 9 actual size2 9 fact1 two ( ! moons ( ! out] planets are actually l>g] ?an ! smalle/ planet ,m]cury1 b !y are v small 9 proportion to ! size ( ! planets ar\nd :i* !y revolve4 ,m>s1 ! next planet beyond ! e>?1 ! ne>e/ ( ! sup]ior or out] planets1 has two t9y moons t be> ! names ( ,deimos & ,phobos1 respectively4 ,!y are bo? less ?an tw5ty miles 9 diamet] & revolve v ne> to ! surface ( ,m>s4 ,!y c only be se5 ) ! aid ( v p[]ful telescopes4 ,! inn] moon1 ,phobos1 is unique 9 ! sol> sy/em = x makes ?ree trips ar\nd ,m>s :ile ! planet is turn+ once on its axis4 ,jupit]1 ! next planet outw>d f ! sun1 is almo/ a sun itself to its ext5sive family ( n9e moons4 ,f\r ( ^! moons 7 fir/ se5 ab\t ?ree hundr$ ye>s ago :5 ,galileo po9t$ 8 fir/ crude telescope at ! heav5s & any "o c n[ see !m ) ! aid ( an op]a glass4 ,"o ( ! f\r is equal 9 size to our own moon2 ! o!rs surpass x 9 size4 ,^! moons are mo/ int]e/+ little bodies to obs]ve4 ,_! eclipses 9 ! %ad[ ( ,jupit]1 occultations or disappe>ances beh9d 8 disk1 & ! transits ( ! %ad[s z well z ! moons !mselves across ! face ( ! planet c be easily se5 ev5 ) ! smalle/ telescope4 ,! five rema9+ moons h all be5 discov]$ 9 mod]n times4 ,!y are extremely small bodies visible only 9 l>ge telescopes4 ,satellite ,v is ! ne>e/ ( all ! moons to ,jupit]4 ,! o!r f\r are at great di/ances f ! planet4 ,! planet ,saturn has n9e moons4 ,titan1 ! l>ge/1 is ne>ly equal 9 size to ,jupit]'s l>ge/ moon1 & is l>g] ?an ,m]cury2 f\r ( ! o!r moons h diamet]s betwe5 "o ?\s& & two ?\s& miles 9 l5g?4 ,s9ce ,saturn is ne>ly twice z f> f ! sun z ,jupit] 8 moons are m difficult to obs]ve1 ?\gh ! two l>ge/ are visible 9 small telescopes4 ,saturn is unique 9 ! sol> sy/em 9 possess+ 9 addition to 8 n9e satellites a mo/ wond]ful r+ sy/em1 compos$ ( sw>ms ( m9ute moonlets1 ea* pursu+ its individual pa? ar\nd ! planet4 ,x is ?is unusual r+ sy/em t makes ,saturn ! mo/ int]e/+ to obs]ve telescopically ( all ! planets4 ,! planet ,uranus has f\r satellites & ,neptune "o4 ,^! planets & _! satellites _c be well obs]v$ on acc\nt ( _! great di/ances f ! e>?4 ,! indi/9ctness ( surface m>k+s makes x impossible to det]m9e ! p]iod ( rotation ( ^! two out] planets on _! axes4 ,x is believ$ t _! rotation is v rapid1 h[ev]1 z is ! case ) ! o!r planets ,jupit] & ,saturn4 ,all ! planets 9 ! sol> sy/em fall naturally into two gr\ps4 ,jupit]1 ,saturn1 ,uranus1 & ,neptune1 ! memb]s ( ! out] gr\p1 h on ! av]age1 diamet]s t5 times z great &1 !re=e1 volumes "o ?\s& times z great z ,m]cury1 ,v5us1 ,e>? & ,m>s1 ! memb]s ( ! inn] or t]re/rial gr\p4 ,illu/ration3 ,a4 ,,v5us4 ,b4 ,,m>s4 ,c4 ,,jupit]4 ,d4 ,,saturn4 ,tak5 by ,pr(4 ,e4 ,e4 ,b>n>d ) ! #dj-;in* telescope ( ! ,y]kes ,obs]vatory1 ) exception ( ,saturn1 :i* 0 tak5 by ,pr(4 ,b>n>d on ,mt4 ,wilson4 ,,note3 ,! read] mu/ be> 9 m9d t ! telescopic views ( ! f\r planets h n be5 r$uc$ to ! same scale & s are n to be comp>$ 9 size4 ,! t]re/rial planets are ! pigmies ( ! sol> sy/em1 ! out] planets are ! giants4 ,! d5sities ( ! planets ,m]cury1 ,v5us1 ,e>? & ,m>s are sev]al times great] ?an ! d5sity ( wat]4 ,!y are all extremely heavy bodies = _! size1 & probably h rigid int]iors ) surface cru/s4 ,! exi/5ce ( life on ,m]cury is made impossible by ! abs5ce ( an atmosph]e4 ,v5us & ,m>s bo? h atmosph]es & x is possible t bo? ( ^! planets may support life4 ,m>s has probably be5 ! mo/ discuss$ ( all ! planets1 ?\gh ,v5us is ! ,e>?'s tw9 planet 9 size1 mass1 d5sity & surface gravity1 j z ,uranus & ,neptune are ! tw9s ( ! out] gr\p4 ,x is n[ believ$ t wat] & vegetation exi/ on ,m>s4 ,! r$di% color ( ?is planet is suppos$ to be due to its ext5sive des]t tracts4 ,! nature ( c]ta9 peculi> m>k+s on ?is planet1 kn[n z canals1 /ill cont9ues to be a matt] ( dispute4 ,x is g5]ally believ$ s9ce air1 wat] & vegetation exi/ on ,m>s1 t "s =m ( animal life also exi/s !re4 ,! l5g? ( ! day on ,m>s is kn[n v accurately1 = ! r>5ess ( its atmosph]e p]mits u to see readily _m ( its surface m>k+s4 ,! l5g? ( ! day is ab\t tw5ty-f\r & "o-half h\rs1 & ! seasonal *anges on ,m>s /rongly resemble our own1 ?\gh ! seasons on ,m>s are twice z long z !y are on our own planet s9ce ! ,m>tian ye> is twice z long z ! t]re/rial ye>4 ,! "q ( life on ,v5us dep5ds l>gely ^u ! l5g? ( ! planet's rotation p]iod4 ,?is is /ill unc]ta9 s9ce no def9ite surface m>k+s c be f\nd on ! planet by :i* ! p]iod ( its rotation c be det]m9$4 ,s d5se is ! atmosph]e ( ,v5us t its surface is1 app>5tly1 always hidd5 f view b5ea? a canopy ( cl\ds4 ,x is ! m g5]al belief t ,v5us1 z well z ,m]cury1 rotates on its axis 9 ! same "t t x takes to make a revolution ar\nd ! sun4 ,9 ?is case ! same side ( ! planet is always turn$ t[>d ! sun &1 z a result1 ! surface is divid$ into two hemisph]es--"o ( p]petual day1 ! o!r ( p]petual night4 ,?is peculi> =m ( rotation 9 :i* ! p]iod ( rotation & revolution are equal is by no means unkn[n 9 ! sol> sy/em4 ,our own moon always keeps ! same face turn$ t[>d ! e>? & !re are reasons = believ+ t "s ( ! satellites ( ,jupit] & ,saturn rotate 9 ! same mann]4 ,life on any "o ( ! out] planets is impossible4 ,! d5sity ( ^! planets av]ages ab\t ! same z ! d5sity ( ! sun1 :i* is a little high] ?an ! d5sity ( wat]4 ,! d5sity ( ,saturn is ev5 less ?an wat]4 ,9 o!r words1 ,saturn w\ld float 9 wat] & x is ! lighte/ ( all ! planets4 ,x is assum$ f ^! facts t ! f\r out] planets are l>gely 9 a gase\s condition4 ,!y all possess d5se atmosph]es &1 9 spite ( _! huge size1 rotate on _! axis ) great rapidity4 ,! two ^: rotation p]iods are kn[n1 ,jupit] & ,saturn1 turn on _! axis 9 ab\t t5 h\rs4 ,on acc\nt ( ?is rapid rotation & _! gase\s condition bo? ,jupit] & ,saturn are noticeably flatt5$ at ! poles4 ,! t]re/rial planets are sep>at$ f ! out] gr\p by a wide gap4 ,)9 ?is space are to be f\nd ! a/]oid or planetoid gr\p4 ,!re are kn[n to be ov] n9e hundr$ & fifty ( ^! m9or bodies ^: diamet]s range f five hundr$ miles = ! l>ge/ to ?ree or f\r miles = ! smalle/4 ,!re are only f\r a/]oids ^: diamet]s exce$ "o hundr$ miles & ! majority h diamet]s ( less ?an tw5ty miles4 ,! total mass ( ! a/]oids is mu* less ?an t ( ! smalle/ ( ! planets4 ,x 0 believ$ at "o "t t ^! small bodies 7 fragm5ts ( a %att]$ planet1 b ?is view is no long] held4 ,! a/]oids z well z ! comets & meteors probably repres5t ! mat]ial ( ! primitive sol> nebula t 0 n swept up :5 ! l>g] planets 7 =m$4 ,) few exceptions ! a/]oids are only to be se5 9 l>ge telescopes & !n only z />-l po9ts ( light4 ,mo/ ( !m are simply huge rocks & all are necess>ily devoid ( life s9ce su* small bodies h n suffici5t gravitational =ce to hold an atmosph]e4 ,! revolution ( ! planets ar\nd ! sun & ( ! satellites ( ! planets ar\nd ! prim>y planets are p]=m$ accord+ to kn[n laws ( motion t make x possible to =etell ! positions ( ^! bodies ye>s 9 advance4 ,a/]oids & comets also obey ^! same laws1 & aft] ?ree obs]vations ( ! positions ( "o ( ^! bodies h be5 obta9$ its future movem5ts c be pr$ict$4 ,all ! planets & _! satellites are ne>ly p]fect sph]es4 ,!y all1 ) few exceptions1 rotate on _! axes & revolve ar\nd ! sun1 or1 9 ! case ( moons1 ar\nd _! prim>ies1 9 ! same direction1 f we/ to ea/4 ,only ! two out]mo/ satellites ( ,jupit]1 ! out]mo/ satellites ( ,saturn & ! satellites ( ,uranus & ,neptune retrograde or travel 9 _! orbits f ea/ to we/1 :i* is opposite to ! direction ( motion ( all ! o!r planets & satellites4 ,! pa?s ( all ! planets ar\nd ! sun are ellipses t are ne>ly circul>1 & !y all lie ne>ly 9 ! same plane4 ,! a/]oids h orbits t are m flatt5$ or elliptical & ^! orbits are 9 "s in/ances highly incl9$ to ! planet>y orbits4 ,! comets h orbits t are usually v elongat$ ellipses or p>abolas4 ,"s ( ! comets may be only *ance visitors to our sol> sy/em1 ?\gh a/ronom]s g5]ally believe t !y are all p]man5t memb]s4 ,pa?s ( comets pass ar\nd ! sun at all angles & "s comets move 9 _! orbits f we/ to ea/1 :ile o!rs move 9 ! opposite direction or retrograde4 ,! behavior ( ! a/]oids & comets is n at all 9 accord ) ! !ory t 01 until rec5tly1 univ]sally advanc$ to expla9 ! orig9 ( ! sol> sy/em4 ,"s a/ronom]s h made attempts to modify ! nebul> hypo!sis t has held sway = s _m ye>s1 9 ord] to make x fit 9 ) m rec5t discov]ies1 b o!rs feel t a new !ory is n[ requir$ to expla9 ! orig9 ( ! sol> sy/em4 ,sev]al !ories h be5 advanc$ b no new !ory has yet def9itely replac$ ! fam\s nebul> hypo!sis ( ! not$ ,fr5* a/ronom] ,la ,place4 ,,xviii ,,! ,,orig9 ,,( ,,! ,,e>? ,x is n possible to consid] ! "q ( ! orig9 ( ! e>? ap>t f ! "q ( ! orig9 ( ! sol> sy/em4 ,t all ! planets1 z well z ! a/]oids1 orig9at$ f a common p>5t-mass has nev] be5 s]i\sly que/ion$4 ,all ( ^! bodies revolve ab\t ! sun1 & rotate ^u _! axes 9 ! same direction--f we/ to ea/4 ,moreov]1 all ( ! planet>y orbits lie v ne>ly 9 ! same plane & are ne>ly circul> 9 =m4 ,! orbits ( ! a/]oids are m elliptical & m highly incl9$ to "o ano!r ?an are ! orbits ( ! planets1 b on ! av]age !y are nei!r v elliptical nor v highly incl9$ to ! planet>y orbits4 ,! sun rotates ^u its axis 9 ! same direction 9 :i* ! planets rotate & p]=m _! revolutions1 & ! orbits ( ! planets are incl9$ at small angles to ! plane ( ! sun's equator4 ,^! facts are all significant & _c be ov]look$ 9 =mulat+ a !ory to expla9 ! orig9 ( ! planet>y sy/em 9 g5]al & ( ! e>? 9 p>ticul>4 ,presumably ! planets & a/]oids =m$ at "o "t a "p ( a c5tral body :i* rotat$ on its axis 9 ! direction 9 :i* !y n[ revolve ab\t ! sun4 ,:5 & by ! op]ation ( :at =ce1 ext]nal or int]nal1 !y 7 sep>at$ f ?is c5tral body is ! "q4 ,9 #agif ,la ,place advanc$ 8 celebrat$ nebul> hypo!sis to expla9 ! orig9 ( ! sol> sy/em4 ,x 0 receiv$ ) favor bo? by sci5ti/s & laym51 & 9 a %ort "t 0 almo/ univ]sally accept$ z closely approximat+ to ! tru?4 ,accord+ to ! nebul> hypo!sis ! sol> nebula f :i* ! planet>y sy/em 0 =m$1 orig9ally ext5d$ at lea/ z f> z ! orbit ( ,neptune & rotat$ sl[ly 9 ! direction 9 :i* ! planets n[ revolve4 ,z x lo/ heat by radiation & contract$ "u ! gravitation ( its p>ts its rate ( rotation increas$4 ,:5 ! c5trifugal 7c5t]-flee+7 =ce at ! equator equall$ ! gravitational =ce direct$ t[>d ! c5t]1 a r+ w\ld be left beh9d by ! contract+ nebula4 ,su* a r+ w\ld n be absolutely uni=m & w\ld break at "s po9t & ga!r into a planet>y mass "u ! gravitation ( its p>ts4 ,?is planet>y mass w\ld ab&on r+s 9 turn & ^! w\ld break up to =m satellites4 ,successive r+s 7 suppos$ to h be5 ab&on$ at int]vals by ! sol> nebula at ! pres5t di/ances ( ! planets f ! sun 9 ! mann] describ$ above until ! orig9al sol> nebula _h contract$ to its pres5t size4 ,! r+s ( ,saturn 7 suppos$ to be ! s+le example rema9+ ( ?is process ( =m+ planets & satellites f a contract+ nebul\s mass4 ,! ,la ,placian hypo!sis attempt$ to expla9 :y all ! planets & _! satellites revolve 9 ! same direction 9 :i* ! sun turns on its axis1 9 ne>ly circul> orbits & ne>ly 9 ! same plane4 ,at ! "t x 0 advanc$ x appe>$ to be 9 accord ) all ! facts !n kn[n reg>d+ ! sol> sy/em4 ,! planetoids ) _! int]lac+ & 9 "s in/ances highly incl9$ & elliptical orbits 7 !n undiscov]$4 ,x w\ld h be5 impossible = !m to h be5 =m$ by ! ab&onm5t ( successive r+s f a c5tral1 rotat+ mass4 ,! con/itution ( ,saturn's r+s 0 unkn[n at ?is "t2 also ! fact t ! moonlets ( ! inn] r+ revolve ab\t ,saturn 9 half ! "t requir$ = ! planet to turn on its axis--ano!r impossibility "u ! nebul> hypo!sis1 =1 accord+ to ! assumptions ( ! nebul> hypo!sis x w\ld be impossible = a satellite to revolve ab\t a c5tral body 9 a %ort] "t ?an t body turns on its axis4 ,! satellites ( ,m>s 7 n discov]$ until _m ye>s lat]1 z well z ! retrograd+ satellites ( ,jupit] & ,saturn1 all pres5t+ difficulties 9 ! way ( accept+ ! nebul> hypo!sis )\t radical *anges4 ,attempts1 mo/ly unsuccessful1 h be5 made f "t to "t to make ^! exceptional cases fit 9 ) ! requirem5ts ( ! nebul> hypo!sis4 ,! !ory t ! sun's heat 0 ma9ta9$ by ! contraction ( ! orig9al sol> nebula1 :i* w\ld cause its temp]ature to rise1 appe>$ to give consid]able support to ! !ory ( ,la ,place1 b ! ma!maticians got to "w & %[$ t ! am\nt ( heat t w\ld be furni%$ by ! contraction ( ! sun f beyond ! orbit ( ,neptune to its pres5t dim5sions w\ld be suffici5t to supply heat to ! e>? at ! pres5t rate = only tw5ty-five million ye>s1 a p]iod f> too brief1 ! geologi/s & biologi/s said1 to cov] all ! va/ cyclical *anges t are kn[n to h tak5 place ^u ! surface ( ?is planet s9ce its surface cru/ 0 =m$4 ,evid5tly gravitational contraction is by no means ! only or ev5 ! *ief s\rce ( ! sun's heat4 ,x 0 also %[n indisputably1 t x w\ld h be5 impossible = successive r+s to h be5 ab&on$ at c]ta9 def9ite int]vals by a contract+ nebula1 & grant$ a r+ c\ld h be5 =m$ x w\ld h be5 impossible = x to cond5se into a planet1 s9ce =ces resid+ 9 ! sun w\ld (fset ! gravitation ( its p>ts4 ,:5 ,la ,place advanc$ 8 fam\s !ory x 01 to use 8 own words1 ) t di/ru/ :i* ev]y?+ ought to inspire t is n a result ( obs]vation or ( calculation4 ,7 ,la ,place liv+ today he w\ld be1 we believe1 ! fir/ to ab&on a !ory t is n[ kn[n to be 9 accord nei!r ) obs]vation nor calculation4 ,depriv$ ( a !ory t has s]v$ to expla9 ! out/&+ features ( ! sol> sy/em m or less adequately = "o hundr$ & tw5ty-five ye>s1 a/ronom]s are seek+ 9 ! light ( rec5t obs]vations & discov]ies to =mulate a satisfactory !ory ( ! orig9 ( ! sol> sy/em4 ,9 ! planetesimal !ory ( ,*amb]l9 & ,m\lton & ! rec5tly sugge/$ !ory ( ! well-kn[n ,engli% ma!matician1 ,jeans1 a second sun pass+ close to our own sun is assum$ to h be5 ! cause ( ! orig9 ( ! planet>y sy/em4 ,! effect ( ! close approa* ( su* a sun w\ld be ! ejection ( a /ream ( matt] f our sun1 z we t]m x1 9 ! direction ( ! pass+ body & also 9 a diametrically opposite direction4 ,?is ejection w\ld be cont9u\s z long z ! />s rema9$ ne> "o ano!r1 ! height atta9$ by ! eject$ /ream decreas+ z ! pass+ /> rec$$4 ,! result w\ld be ! =mation ( a spiral nebula 9 :i* ! motion ( ! eject$ p>ticles--planetesimals--w\ld be across ! spiral arms1 t[>d & away f ! pass+ />4 ,aft] ! sun _h rec$$ s f> z to h no fur!r effect ^u ^! eject$ p>ticles !y w\ld revolve ab\t ! sun 9 m or less elliptical orbits :i* w\ld gradually be r$uc$ to ne>ly circul> =ms by repeat$ collisions betwe5 planetesimals4 ,l>g] nuclei w\ld be =m$ & ^! w\ld gradually sweep up small] fragm5ts & become ! planets ( ! pres5t sy/em4 ,small] nuclei 9 ! vic9ity ( l>g] ones w\ld become _! satellites & 9 ! c\rse ( _m millions ( ye>s all ( ! l>g] fragm5ts w\ld be swept up by ! planet>y nuclei & _! satellites--leav+ only ! a/]oids1 comets & meteors z survivors ( ! orig9al spiral sy/em4 ,x mu/ be borne 9 m9d t a spiral nebula =m$ by ! close approa* ( two suns w\ld resemble 9 =m only ! great spiral nebul t are kn[n to exi/ by hundr$s ( ?\s&s 9 ! heav5s4 ,^! are f> too ext5sive to =m any?+ s small z a s+le sol> sy/em1 b might cond5se into sy/ems compos$ ( _m suns--ei!r galaxies or /> clu/]s4 ,jean's sugge/$ !ory ( ! orig9 ( ! planet>y sy/em diff]s 9 its details f ! above1 ?\gh a pass+ sun is assum$ to be ! di/urb+ =ce t causes ! ejection ( a /ream ( matt] :i* cond5ses to =m ! planets & _! satellites4 ,! orig9 ( ! inn] planets is left greatly 9 d\bt by ?is !ory1 h[ev]1 & ! sy/em :i* int]e/s u *iefly--! e>?-moon sy/em--is ! "o ab\t :i* x is mo/ difficult to arrive at any def9ite conclusion4 ,our own sun1 x is assum$1 0 d>k & cold1 ( l[ d5sity & ) a diamet] ab\t equal to t ( ,neptune's orbit at ! "t ( ! cata/rophe :i* is plac$ at "s #cjj1jjj1jjj ye>s ago4 ,9 ,jean's words1 444 ,! "t = arriv+ at conclusions 9 cosmogony has n yet come--& x mu/ be left to future inve/igators arm$ ) m ma!matical & obs]vational k ?an we at pres5t possess to pron\nce a f9al decision4 ,h[ev]1 s9ce ,la ,place advanc$ 8 celebrat$ nebul> hypo!sis1 great advances 9 a/ronomy h be5 made1 & man is 9 a bett] position to !orize on ?is fasc9at+ problem today ?an he 0 "o hundr$ & tw5ty-five ye>s ago4 ,all su* !ories mu/ necess>ily be reg>d$ z work+ hypo!ses only1 to be disc>d$ or modifi$ z our k & und]/&+ ( ! laws ( ! univ]se increase4 ,no !ory c ev] be reg>d$ z f9al or p]fect4 ,! discov]y ( radio-activity furni%es u ) new mat]ial = new !ories4 ,! sun & ! planets may be & probably are f> old] ?an we ev] dream$ c\ld be possible4 ,x is no long] necess>y or reasonable to assume t a greatly ext5d$ sol> nebula once exi/$ & suppli$ ! planets ) heat ?r\gh gravitational contraction or to place a "t limit ^u ! p]iod requir$ = ! =mation ( ! planets & _! satellites t is n 9 accord ) ! requirem5ts ( o!r sci5ces4 ,we "k today t !re exi/ )9 ! sun p[]ful repulsive =ces1 :i* ev5 "u pres5t conditions occasionally eject gase\s matt] to heights ( five hundr$ ?\s& miles or m ) a velocity ( ov] two hundr$ miles p] second4 ,small *anges 9 ! velocity ( ejection produce great diff]5ces 9 ! height ( ! eject$ columns4 ,) an initial velocity ( ?ree hundr$ & eighty miles p] second1 matt] w\ld be ?r[n f ! sol> surface to a height ( fifty million miles4 ,7 ! velocity ( ejection ?ree hundr$ & eighty-?ree miles p] second ! height ( ! column w\ld be five hundr$ million miles1 :ile a fur!r increase 9 ! initial velocity w\ld s5d matt] away f ! sun1 nev] to return4 ,in/ead ( suns & sol> sy/ems evolv$ f nebul we are n[ m famili> ) ! idea ( nebul evolv$ f />s ?r\gh "s t]rific cataclysm z 9 ! case ( novas or tempor>y />s4 ,x is n[ kn[n t !re exi/ 9 c]ta9 p>ts ( space a numb] ( %>ply def9$ />s surr\nd$ by ext5sive nebul\s envelopes4 ,are ^! possibly suns t are go+ ?r\gh ! process ( =m+ _! planet>y sy/ems8 ,x is n[ kn[n t pressure ( light & electrical repulsion are =ces to be reckon$ ) 9 ! evolution ( />s & nebul z well z gravitational contraction4 ,x has long be5 felt t ! peculi> =mations exi/+ among ! va/ irregul> gase\s nebul c\ld n be expla9$ z gravitational effects alone4 ,light-pressure & electrical repulsion1 z well z gravitation are at "w )9 ! sol> sy/em & ! sun is ! seat ( p[]ful di/urbances :i* produce p]iodic outbur/s ( exceptional activity & :i* may h produc$ 9 ! di/ant pa/ m />tl+ effects ?an any ) :i* we are famili> at pres5t4 ,! e>? & moon =m a sy/em t is 9 a way unique4 ,no satellite 9 ! sol> sy/em is s l>ge 9 proportion to its prim>y z is our own moon4 ,se5 f ! di/ance ( ,v5us or ,m>s1 ! two bodies w\ld app>5tly =m a d\ble />4 ,! diamet] ( ! moon is "o-f\r? t ( ! e>?4 ,satellite ,,iii ( ,jupit] f> exce$s our own moon 9 actual size b its diamet] is only ab\t f\r-hundr$?s ( ! diamet] ( ! planet ab\t :i* x revolves4 ,! diamet] ( ,titan1 ! l>ge/ satellite ( ! ,saturnian sy/em1 be>s ! same ratio to ! diamet] ( ,saturn4 ,moreov]1 all ! ne>] satellites ( ,jupit] & ,saturn lie ne>ly 9 ! equatorial planes ( ^! planets1 b ! orbit ( ! moon is incl9$ at a high angle to ! plane ( ! e>?'s equator4 ,x is n difficult to believe t ! satellites ( ,jupit] or ,saturn 7 at "s "t ?r[n (f f ! equatorial belts ( _! prim>ies1 j z ! planets !mselves may h be5 eject$ f ! equatorial belt ( ! sun1 b we _c s readily believe t our own satellite 0 =m$ f ! e>? 9 a simil> mann]4 ,! moon's orbit lies ne>ly 9 ! plane ( ! sun's equator1 h[ev]1 & x is conceivable t bo? e>? & moon 7 simultane\sly eject$ f ! equatorial zone ( ! sun1 ! two nuclei be+ s close toge!r t ! small] "o rema9$ "u ! gravitational control ( ! l>g]4 ,! difficulties 9 ! way ( believ+ t ! moon once =m$ a "p ( ! e>? are v great4 ,x c be %[n ma!matically t if ! two bodies at "o "t =m$ a s+le mass x w\ld h be5 impossible = ! moon to break away f ! e>?1 unless ! =ce t caus$ ! sep>ation 7 suffici5t to hurl ! moon to a great] di/ance ?an two & a half times ! e>?'s radius4 ,! ma!matician1 ,ro*e1 f\nd out by computation t a satellite c\ld n rema9 intact )9 ?is di/ance ( ! planet1 b w\ld be brok5 up into small fragm5ts "u ! effects ( ! tides rais$ by ! l>g] body4 ,if1 !n1 ! moon _h orig9ally be5 eject$ f ! e>? to a less di/ance ?an two & "o-half radii ( ! e>? 7#b4dd to be exact7 x w\ld h be5 dis9tegrat$ into small p>ticles1 or moonlets1 "u ! tidal /ra9s ex]t$ ^u x by ! e>? & w\ld h be5 gradually di/ribut$ ab\t ! e>? 9 ! =m ( a meteoric r+ :i*1 9 ! c\rse ( ages1 w\ld be absorb$ by ! e>?1 j z ,saturn is n[ gradually absorb+ its r+s4 ,! planets diff] greatly 9 d5sity4 ,! m di/ant & l>g] planets--,jupit]1 ,saturn1 ,uranus & ,neptune--h d5sities equal to or less ?an t ( ! sun4 ,! d5sities ( ! inn] planets--,m]cury1 ,v5us1 ,e>? & ,m>s--are1 relatively1 extremely high1 ! d5sity ( ! ,e>?'s core be+ ab\t t ( meteoric iron4 ,! d5sities ( ,m]cury & ,v5us are slightly less ?an t ( ! e>? & ! d5sities ( ,m>s & ! moon ab\t equal to t ( ! e>?'s cru/4 ,if a /ream ( matt] 7 eject$ f ! sun "u ! influ5ce ( "s ext]nal =ce1 su* z t ex]t$ by a pass+ />1 ! outly+ p>ts ( ! /ream w\ld consi/ ( ! light] elem5ts & ! l[] p>ts ( ! heavi] elem5ts1 s9ce ! light] sol> elem5ts lie at or ne> ! surface ( ! sun & ! heavi] elem5ts at great] dep?s4 ,at ! "t ( ejection ! light] elem5ts w\ld be ?r[n to great di/ances & w\ld g to =m ! less d5se out] planets2 ! heavi] elem5ts w\ld g to =m ! inn] planets ( high d5sity4 ,x is conceivable t ejection ( sol> mat]ial might h tak5 place "u ! influ5ce ( c]ta9 =ces at "w )9 ! sun itself1 su* z electrical repulsion or pressure ( light :i* might become p[]ful en\gh "u c]ta9 conditions to ov]come ! effect ( gravitation4 ,next to no?+ is kn[n ab\t ! physical /ate ( matt] at great sol> dep?s1 :]e abnormal conditions ( temp]ature & pressure mu/ exi/1 & :]e great physical *anges & di/urbances may h tak5 place 9 ! pa/4 ,ev5 today sol> activity goes ?r\gh a cycle ( *ange dur+ ! sun-spot p]iod1 & _m millions ( ye>s ago ! sun-spot cycle ( sol> activity may h be5 f> diff]5t f :at x is today & a f> m p[]ful factor 9 produc+ *anges 9 ! sol> sy/em4 ,outbur/s ( novas indicate t ag5cies mak+ = peace & ord] are n ! only ones at "w among ! />s4 ,! cause ( su* outbur/s has nev] be5 satisfactorily expla9$4 ,! !ory t !y are caus$ by ! close approa* ( two suns or by ! enc\nt] ( a /> ) a d>k nebula does n acc\nt = all ( ! circum/ances ( su* outbur/s4 ,! nebul\s matt] se5 ab\t a nova aft] ! outbur/ is n[ g5]ally believ$ to h be5 expell$ f ! /> itself at ! "t ( ! cata/rophe & may conceivably be ! /uff ( :i* planet>y sy/ems are made4 ,at "s epo* 9 ! pa/1 probably at lea/ "o ?\s& million ye>s ago1 our own sun may h und]gone "s cataclysmic *ange & ?is may1 conceivably1 h be5 br\ght ab\t by di/urbances )9 ! sun itself4 ,elem5ts may h be5 s =m$ & di/ribut$ )9 ! int]ior ( ! sun t friction & int]nal in/ability result$ & 9 "t produc$ an upheaval ( sol> elem5ts ) initial velocities s great t1 possibly1 ?r\gh electrical repulsion & light-pressure1 portions ( ! eject$ /reams 7 p]man5tly deta*$ f ! sun & became ! nuclei ( future planets4 ,9 "s su* way1 x is conceivable1 our own planet ,e>? & ! o!r memb]s ( our sol> sy/em may h be5 br\ght into exi/5ce 9 ! dim & di/ant pa/--_m hundr$ million ye>s ago4 ,,xix ,,jupit] ,,& ,,8 ,,n9e ,,moons ,jupit] %9es by reflect$ sunlight ) a brilliancy t usually exce$s t ( ! brighte/ ( ! />s1 ,sirius4 ,:5 se5 dur+ ! midnight h\rs ! rem>kable unflick]+ brightness ( ?is l>ge/ & mo/ di/+ui%$ memb] ( ! sol> sy/em at once s]ves to set x ap>t f ! sc9tillat+ />s f> beyond4 ,!re is b "o planet1 ,v5us1 t always surpasses ,jupit] 9 brilliancy1 ?\gh ,m>s on ! occasions ( its close approa*es to ! e>? may equal or slightly surpass ,jupit] 9 brightness4 ,z ,v5us nev] dep>ts m ?an =ty-eight degrees f ! sun1 & s is nev] se5 9 ! midnight h\rs1 ,jupit] usually %9es )\t a rival :5 visible at midnight4 ,to "o :o has obs]v$ ! two planets toge!r ! silv]y radiance & surpass+ brilliancy ( ,v5us1 due n to its size1 b to its comp>ative ne>ness to ! e>?1 at once s]ves to di/+ui% x f ! gold5 gl[ ( ,jupit]4 ,ev5 ! smalle/ telescopes ( two- or ?ree-in* ap]ture w %[ ! f\r hi/oric moons ( ,jupit] :i* 7 ! fir/ cele/ial objects to be discov]$ :5 ,galileo turn$ 8 crude telescope to ! heav5s 9 ! ye> #afaj4 ,! fact t ^! t9y po9ts ( light 7 actually revolv+ ar\nd ! great planet 0 soon detect$ by ! fam\s a/ronom] & we c imag9e ) :at brea?less int]e/ he obs]v$ ^! satellites ( ano!r _w ^: discov]y dealt su* a sev]e bl[ to ! old ,ptolemaic !ory t ! e>? 0 ! c5t] ( ! univ]se4 ,x 0 n until ! great telescopes ( mod]n times 7 inv5t$ t ! five additional moons ( ,jupit] 7 discov]$4 ,! f\r satellites fir/ obs]v$ by ,galileo 7 fancifully nam$ ,io1 ,europa1 ,ganym$e & ,calli/o1 9 ! ord] ( _! positions outw>d f ! planet1 b ^! names are r>ely us$ n[1 ! satellites be+ designat$ = conv5i5ce ,i1 ,,ii1 ,,iii & ,,iv1 respectively4 ,! fir/ ( ! new satellites to be discov]$ 0 ,satellite ,v1 :i* is ! ne>e/ to ,jupit] ( all ! n9e moons4 ,x is an extremely small body1 n m ?an "o hundr$ miles 9 diamet]1 & to discov] ?is t9y body z x skirt$ rapidly ar\nd ! great planet )9 sixty-sev5 ?\s& miles ( its surface1 ne>ly lo/ 9 ! gl>+ rays1 0 a difficult feat ev5 = an exp]i5c$ obs]v]4 ,x 0 accompli%$1 h[ev]1 by ,pr(4 ,e4 ,e4 ,b>n>d ) ! great ,lick refractor 9 #ahib4 ,satellite ,v is hopelessly beyond ! rea* ( any b ! greate/ telescopes1 z are also ! f\r satellites discov]$ s9ce t date4 ,9 fact1 mo/ ( ^! t9y moons are obs]v$ photographically4 ,satellites ,,vi & ,,vii 7 discov]$ photographically 9 #aije4 ,!y are bo? ab\t sev5 million miles f ! planet & _! pa?s loop ?r\gh "o ano!r2 !y are1 moreov]1 highly incl9$ to ea* o!r at an angle ( ne>ly ?irty degrees4 ,:5 ne>e/ toge!r !y are sep>at$ by a di/ance ( two million miles4 ,two m extremely small bodies1 kn[n z ,satellites ,,viii & ,,ix1 h be5 discov]$ s9ce !n1 "o at ,gre5wi*1 ,engl&1 9 #aijh1 ! o!r at ! ,lick ,obs]vatory 9 #aiad4 ,^! excessively fa9t bodies are ! mo/ remote satellites ( ,jupit] & !y are ( p>ticul> int]e/ because !y travel ar\nd ! planet 9 a retrograde direction1 or f ea/ to we/1 :i* is opposite to ! direction ( revolution prevail+ 9 ! sol> sy/em4 ,! n9? & mo/ di/ant satellite ( ,saturn also retrogrades1 or revolves 9 a clockwise r ?an a c\nt]-clockwise direction ar\nd ! planet4 ,"o explanation giv5 = ?is peculi>ity ( ! out]mo/ satellites ( ,jupit] & ,saturn is t ?is backw>d revolution ar\nd ! planet is m /able :5 ! satellites are at great di/ances f ! prim>y1 & ! gravitational control t ! planet ex]ts is !re=e weak4 ,! moons ( ! planets are1 ( c\rse1 subject to ! attraction ( ! sun z well z to ! attraction ( ! controll+ planet1 & ! great] ! di/ance ( ! satellite f ! planet ! /rong] ! pull ex]t$ by ! sun & ! weak] ! bonds t b9d ! moon to ! planet4 ,beyond a c]ta9 limit x w\ld be impossible = ! planet to hold ! satellite aga9/ ! sun's great] attraction & ! satellite w\ld leave ! planet to revolve directly ar\nd ! sun1 !reby becom+ a planet4 ,x appe>s t z ?is dang] limit is ne>$ x is saf] = ! satellite to back ar\nd ! planet ?an to foll[ ! usual we/ to ea/ direction ( revolution4 ,! eigh? satellite ( ,jupit] is m ?an f\rte5 million & ! n9? m ?an fifte5 million miles f ! p>5t planet & !y require ab\t two ye>s & ?ree ye>s1 respectively1 to complete "o trip ar\nd ,jupit]4 ,:5 we consid] t ,satellite ,v d>ts ar\nd ! planet 9 less ?an twelve h\rs at a di/ance ( only sixty-sev5 ?\s& miles f its surface we realise :at trem5d\s diff]5ces exi/ 9 ! di/ances & p]iods ( revolution ( ! n9e moons4 ,!re is also great disp>ity 9 ! sizes ( ! v>i\s moons4 ,! five moons discov]$ 9 mod]n times are all excessively fa9t & extremely small4 ,! diamet] ( ! l>ge/ ( ^!1 ,satellite ,v1 is less ?an "o hundr$ miles4 ,on ! o!r h&1 ! f\r hi/oric moons ( ,jupit] are ( planet>y dim5sions4 ,! smalle/1 ,satellite ,,ii1 is slightly l>g] ?an our own moon1 :ile ! l>ge/1 ,satellite ,,iii1 has a diamet]1 accord+ to measurem5ts made ) ! #dj-;in* ,y]kes refractor 9 #aiaf1 ( ?ree ?\s& n9e hundr$ & eight miles1 :i* is only f\r hundr$ miles less ?an ! diamet] ( ,m>s4 ,! p]iods ( revolution ( ^! f\r satellites range f "o day & eighte5 h\rs = ! ne>e/1 :i* is ab\t two hundr$ & sixty-"o ?\s& miles f ! c5t] ( ,jupit]1 to sixte5 days & sixte5 & "o-half h\rs = ! mo/ di/ant1 :i* is m ?an "o million "o hundr$ & sixty ?\s& miles f ! planet4 ,^! f\r moons are s ne> to ! great planet t !y are cont9ually dipp+ into 8 huge %ad[ & exp]i5c+ an eclipse ( ! sun :i*1 ow+ to ! ne>ness & great size ( ,jupit]1 la/s = two or ?ree h\rs4 ,at times ( eclipse ! moon sudd5ly disappe>s f ! obs]v]'s view1 ?\gh x may be consid]ably to "o side ( ! planet4 ,its reappe>ance lat] on is j z sudd51 or x may pass out ( ! %ad[ :ile hidd5 f u beh9d ! disk ( ! planet1 9 :i* case its reappe>ance is invisible f ! e>?4 ,! occultations ( ! satellites1 or1 9 o!r words1 _! disappe>ance beh9d ! planet's disk1 are also int]e/+ ph5om5a to obs]ve1 z are _! transits across ! disk ( ! planet z ! satellite passes 9 front ( x4 ,n only ! satellite itself b its %ad[ z well c be se51 a small black dot pass+ ov] ! surface ( ,jupit]4 ,! satellite is totally eclips+ ! sun = ?is small d>k portion ( ! planet's disk4 ,two satellites & _! %ad[s are frequ5tly se5 cross+ ! face ( ! planet at ! same "t4 ,x is possible to obs]ve all ! ph5om5a ( ! satellite's transits & %ad[s1 eclipses & occultations ) v small telescopes4 ,f obs]vations ( ! eclipses ( ,jupit]'s satellites ! important discov]y ( ! f9ite velocity ( light 0 fir/ made z f> back z ! ye> #afge4 ,fa9t surface m>k+s h be5 made out at c]ta9 times on ! l>ge/ ( ! f\r satellites1 ,satellite ,,iii1 & also on ,satellite ,i4 ,obs]vations ( ! m>k+s on ! =m] seem to indicate t x always keeps ! same face turn$ t[>d ,jupit] z does our own moon t[>d ! e>?4 ,!re are also reasons = believ+ t ! equatorial regions ( ,satellite ,i are light color$ & ! pol> regions d>k4 ,!re is ! possibility t =ms ( life may exi/ on ^! satellites ( ,jupit]1 ?\gh !y are m likely b>r51 lifeless worlds1 su* z ,m]cury & ! moon4 ,_! great di/ance f ! e>?1 nev] less ?an ?ree hundr$ & sixty-eight million miles1 makes obs]vations ( _! surface m>k+s v difficult4 ,h[ beautiful beyond description mu/ ! heav5s appe> z view$ f ! satellites ( ,jupit]6 ,view$ f ! di/ance ( ,io1 or ,satellite ,i1 ! mighty planet ,jupit] pres5ts a spectacle su* z ! eye ( man has nev] be5 privileg$ to behold4 ,! huge flatt5$ globe1 n9ety ?\s& miles 9 equatorial diamet]1 equal 9 mass to ?ree hundr$ planets su* z our own & 9 volume to ne>ly f\rte5 hundr$1 fills a space 9 ! heav5s ne>ly tw5ty degrees 9 ext5t z view$ f ?is satellite4 ,fifte5 hundr$ ( our own full moons w\ld h>dly fill ! same space4 ,:irl+ on its axis ) frightful spe$ 9 a p]iod ( less ?an t5 h\rs1 ! huge ball glides rapidly b maje/ically onw>d ?r\gh ! sky4 ,a f> di/ant sun %runk to b "o-fif? ! diamet] ( ! full moon ?r[s light & %ade across ! rapidly *ang+ surface ( ! planet1 ri* 9 ! r$s1 br[ns & yell[s & all ! gorge\s %ades & t9ts ( its d5se1 see?+1 gase\s envelope4 ,! phases ( ! moon on a greatly enl>g$ scale rapidly succe$ ea* o!r on ,jupit] z x is view$ f ! satellite 9 all positions ) ref]5ce to ! sun4 ,! cause ( ! belts ( ,jupit]1 t lie p>allel to ! planet's equator & are con/antly *ang+ 9 numb]1 wid? & %ade1 z well z ! nature ( all ! peculi> spla%es ( color & int5sely :ite flecks t come & g 9 ! d5se atmosph]e ( ! planet w\ld n be su* a my/]y to u 7 x possible to view ! great planet f ! di/ance ( ,satellite ,i1 :i* is ab\t z f> f ! surface ( ,jupit] z ! moon is f ! e>?4 ,x is unc]ta9 :e!r ! planet is entirely gase\s ?r\gh\t or has a c5tral core ( solid or liquid matt]4 ,its d5sity is only "o & "o-qu>t] times t ( wat] & slightly less ?an t ( ! sun1 %[+ t x is compos$ l>gely1 if n entirely1 ( matt] 9 a gase\s /ate4 ,jupit] is a _w z diff]5t f our own z x is possible to imag9e4 ,!re is no visible surface cru/ & !re are no p]man5t m>k+s4 ,diff]5t spots on ! planet's disk give diff]5t p]iods ( rotation %[+ t x is atmosph]ic ph5om5a t we obs]ve4 ,all is con/ant flux & *ange on ,jupit]4 ,d5se vapors arise f a highly heat$ int]ior & spread out into belts p>allel to ! equator 9 ! direction ( ! planet's rotation4 ,f its ne>e/ satellite all ! int]e/+ *anges ( color & =m t con/antly take place 9 ! atmosph]e ( ?is great globe c\ld be obs]v$ 9 great detail4 ,! high p]c5tage ( light & heat t ,jupit] reflects f ! sun to its ne>] satellites makes x a second>y sun to !m ( trem5d\s size ?\gh feeble /r5g?4 ,z se5 f ,satellite ,i ! o!r ?ree major moons ( ,jupit] pres5t all ! phases ( our own moon 9 rapid succession1 due to _! con/antly *ang+ positions ) ref]5ce to ! sun4 ,! five small moons1 discov]$ 9 mod]n times1 are s m9ute t !y are simply />-l po9ts ( light ev5 :5 view$ f ! o!r moons ( ,jupit]4 ,to keep track ( ! rapidly *ang+ positions & v>i\s phases ( ! moons ( ,jupit] z se5 f any "o ( !m1 z well z ! rapid app>5t motion ( ! planet ?r\gh ! sky due to ! revolutions ( ! satellite ar\nd ! planet1 w\ld be a tr\blesome task = an a/ronom] /ation$ on "o ( ^! f> di/ant worlds4 ,x w\ld be a common sight to see 9 ! sky at "o "t ! huge planet1 ! f>-di/ant1 %runk5 sun1 & "o1 two or ?ree moons4 ,se5 f ! moons ( ,jupit] ! con/ellations w\ld appe> z !y d to u on e>?1 = su* a slight *ange 9 position z five hundr$ million miles1 m or less1 is trivial :5 "o is look+ at ! />s4 ,obs]vations ( ! />s f ! ne>e/ moon ( ,jupit] w\ld be att5d$ ) great difficulties at times1 s9ce reflect$ sunlight f a body ne>ly tw5ty degrees 9 diamet] w\ld be extremely tr\blesome1 especially 7 ! phases ( ! planets ne> t ( ! full moon4 ,we "k h[ ! pres5ce ( our own moon 9 ! heav5s at ! full dims ! brightness ( ! />s s t only ! brighte/ />s are se54 ,ev5 z view$ f ! f\r? or mo/ di/ant ( ! major satellites ! planet subt5ds an angle ( ne>ly five degrees4 ,occultations ( ! />s are _m & frequ5t z ! huge planet globe glides swiftly ?r\gh ! heav5s4 ,_m a moonlight night appe>s almo/ z day ow+ to ! pres5ce ( ! enorm\s1 brilliantly reflect+ ball ( light & at times two or ?ree moons 9 addition4 ,only ! brighte/ />s c\ld possibly be se5 "u su* circum/ances4 ,:51 h[ev]1 ! small worlds pass into ! %ad[ ( ! great "m planet & n only ! light ( ! sun b also ! reflect$ light ( ,jupit] disappe>s = _m m9utes1 ! />s %9e =? 9 all _! glory !re z "h4 ,at su* times "s ( ! l>g] moons w\ld usually be se5 %9+ by ! reflect$ light ( ! f> di/ant sun4 ,saturn also w\ld be visible z a magnific5t />1 b beautiful ,v5us & ruddy ,m>s w\ld fail to appe>4 ,t9y bodies1 m]e specks ( light at ?is di/ance1 !y w\ld be lo/ to view 9 ! gl>e ( ! sun4 ,,xx ,,! ,,r+s ,,& ,,moons ,,( ,,saturn ,ne>ly ev]yone has felt at "s "t or o!r a /rong desire to gaze at "s ( ! beauties & wond]s ( ! heav5s ?r\gh a telescope & ! "o object t all ( u wi% to see1 if1 p]*ance1 ?is desire is to be gratifi$ is ,saturn1 ^: unusual r+ sy/em has1 s f> z we "k1 no c\nt]p>t 9 ! sky4 ,all ! planets 9 ! sol> sy/em ) ! exception ( ! two inn]mo/1 ,m]cury & ,v5us1 are att5d$ by satellites1 b ,saturn1 alone1 has 9 addition to a family ( n9e moons1 ?ree di/9ct r+s ( great dim5sions :i* are compos$ ( sw>ms ( m9ute p>ticles revolv+ ar\nd ! planet4 ,:y ,saturn %\ld be ! only planet to possess su* a sy/em ( r+s has nev] be5 expla9$ 9 an entirely satisfactory mann]4 ,!re is an int]e/+ law kn[n z ,ro*e's ,law1 h[ev]1 nam$ f its inve/igator1 t /ates t no satellite ( a planet c exi/ intact ) #b4dd times ! radius ( ! planet4 ,?is limit is spok5 ( z ,ro*e's ,limit & apply+ x to ! planet ,saturn we f9d t ! r+s ( ,saturn fall )9 ?is limit4 ,x does n necess>ily foll[ f ?is t ! m9ute p>ticles ( :i* ! r+s are compos$ are ! %att]$ rema9s ( "o small satellite1 b r t !y are ! mat]ial f :i* a satellite might h be5 =m$ 7 x n s close to ! planet4 ,)9 ,ro*e's ,limit ! mutual attraction ( ! v>i\s p>ticles = ea* o!r t w\ld t5d ev5tually to ga!r !m into "o body is ov]come by tidal =ces t arise f su* close proximity to ! huge planet4 ,! /ress & /ra9 ( su* =ces is s great t no gr\p+ ( p>ticles c take place4 ,?is expla9s1 possibly1 :y ! r+s cont9ue to exi/ 9 _! pres5t condition4 ,! total quantity ( matt] 9 ! r+s is kn[n to be v small1 = x does n di/urb ! motions ( any ( ! ne>] & small] satellites1 ?\gh t9y ,mimas1 six hundr$ miles 9 diamet]1 is only ?irty-"o ?\s& miles beyond ! out] edge ( ! out] r+4 ,an int]e/+ obs]vation 0 made a few ye>s ago ( ! passage ( ! r+s ( ! planet betwe5 u & a />4 ,?\gh ! light ( ! /> 0 dim9i%$ to "o-f\r? ( its normal brightness :5 ! r+s pass$ be=e x1 at no "t 0 its light entirely eclips$ by any ( ! p>ticles4 ,x 0 comput$ t if ! diamet]s ( any ( ! individual p>ticles _h am\nt$ to z mu* z ?ree or f\r miles ! /> w\ld h be5 tempor>ily eclips$4 ,an upp] limit = ! size ( ! moonlets 0 ?us obta9$4 ,! av]age diamet] ( ! p>ticles is probably mu* less ?an ?ree miles4 ,! ?ickness ( ! r+ sy/em is n ov] fifty or "o hundr$ miles1 b its total diamet] is "o hundr$ & sev5ty-two ?\s& miles4 ,!re are1 9 all1 ?ree conc5tric r+s4 ,! fa9t inn] r+1 kn[n z ! crape r+1 is invisible 9 a telescope "u f\r in*es 9 ap]ture4 ,! wid? ( ?is inn] r+ is elev5 ?\s& miles4 ,j beyond ! crape r+ is ! *ief1 bright r+1 eighte5 ?\s& miles 9 wid?4 ,x %ades gradually 9 brightness f its juncture ) ! crape r+ to its mo/ lum9\s portion at its out] edge1 :i* is sep>at$ f ! ?ird or out] r+ by a gap two ?\s& two hundr$ miles 9 wid?1 kn[n z ,cass9i's ,division4 ,! ?ird or out] r+ is elev5 ?\s& miles wide & is less bright ?an ! c5tral r+4 ,! inn] edge ( ! inn] r+ is b six ?\s& miles above ! surface ( ! planet4 ,on acc\nt ( ! curvature ( ! planet ! r+ sy/em is invisible f ! nor? & s\? poles ( ,saturn4 ,z 9 ! case ( ! satellites ( a planet ! inn] p>ticles ( ! r+s revolve ar\nd ! planet m rapidly ?an ! out] p>ticles4 ,! inn]mo/ p>ticles ( ! crape r+ require b five h\rs = "o j\rney ar\nd ,saturn :ile ! out]mo/ p>ticles ( ! out] r+ require "o hundr$ & ?irty-sev5 h\rs1 or ne>ly six days to complete "o revolution4 ,9 addition to ! gap 9 ! r+s kn[n z ,cass9i's ,division sev]al o!r fa9t] divisions exi/4 ,if a gr\p ( moonlets 7 to revolve ar\nd ! planet 9 ! positions m>k$ by ^! gaps _! p]iods ( revolution w\ld be comm5surable ) ! p]iods ( sev]al ( ! satellites ( ,saturn4 ,z a result ! attraction ex]t$ on su* p>ticles by ^! satellites w\ld gradually di/urb _! motion 9 su* a way z to draw !m away f ^! positions4 ,x is ow+1 !re=e1 to ! attraction ( ! satellites ( ,saturn = ! moonlets t ^! gaps 9 ! r+s exi/4 ,z a result ( ! di/urbances produc$ 9 ! motion ( ! moonlets by ! satellites ( ,saturn collisions are b\nd to occur occasionally among ! v>i\s p>ticles4 ,:5 two p>ticles collide ! p]iod ( revolution ( "o or bo? ( !m is r$uc$ & z a result collisions t5d to br+ ! moonlets gradually clos] & clos] to ! surface ( ! planet4 ,! dusky inn] r+1 x is believ$1 may consi/ l>gely ( p>ticles ^: p]iods h be5 cont9ually %ort5$ by collisions4 ,saturn may1 !re=e1 lose its r+ sy/em 9 ! c\rse ( "t ?r\gh its gradually be+ drawn d[n ^u ! planet by collisions ( ! v>i\s p>ticles until all ( ! mat]ial is f9ally swept up by ! planet4 ,su* a *ange w\ld probably require millions ( ye>s1 h[ev]1 z collisions are probably1 on ! :ole1 infrequ5t4 ,x is possible t ! r+ sy/em ( ,saturn may h be5 mu* m ext5sive 9 ! pa/ ?an x is n[ & o!r memb]s ( our sol> sy/em may h _h su* app5dages 9 ! f> di/ant pa/4 ,! appe>ance ( ! r+s ( ,saturn z view$ f our planet *anges p]iodically z a result ( ! revolution ( ! e>? & ,saturn ar\nd ! sun1 :i* places !m 9 con/antly *ang+ positions ) ref]5ce to ea* o!r4 ,! r+s lie 9 ! plane ( ,saturn's equator1 :i* is incl9$ tw5ty-sev5 degrees to its orbit & tw5ty-eight degrees to ! ,e>?'s orbit4 ,s9ce ! position ( ! equator rema9s p>allel to itself :ile ! planet is j\rney+ ar\nd ! sun x happ5s t half ! "t ! e>? is elevat$ above ! plane ( ! r+s & ! rema9d] ( ! "t x lies bel[ ! plane ( ! r+s4 ,twice 9 ! p]iod ( ,saturn's revolution ar\nd ! sun1 :i* occupies ne>ly ?irty ye>s1 ! e>? lies directly 9 ! plane ( ! r+s & at ?is "t ! r+s entirely disappe> f view = a %ort "t4 ,mid-way betwe5 ! two dates ( disappe>ance ! r+s are tilt$ at _! wide/ angle ) ref]5ce to ! e>? & !y are !n se5 to ! be/ advantage4 ,z ! date ( _! disappe>ance approa*es !y appe> m & m l a l9e ( light ext5d+ to ei!r side ( ! planet's equator4 ,ev5 9 ! mo/ p[]ful telescope ! r+s entirely disappe> f view = a few h\rs at ! "t ! e>? lies exactly 9 ! same plane4 ,x is at ?is "t t ! ball ( ! planet is be/ se54 ,its flatt5+ at ! poles1 :i* is ne>ly t5 p] c5t4 ( its equatorial diamet] !n gives x a decid$ly oval appe>ance4 ,ord9>ily "o ( ! hemisph]es ( ,saturn is p>tly or entirely conceal$ by ! r+s s t ! oblate =m is n s noticeable4 ,x 0 ! *ange 9 ! tilt & visibility ( ! r+s t s p]plex$ ,galileo :5 he attempt$ to make out ! nature ( ^! app5dages ( ,saturn ) 8 crude telescope ( insuffici5t magnify+ p[]4 ,s great 0 8 bewild]m5t :5 ! r+s f9ally disappe>$ t he cri$ out 9 despair t ,saturn mu/ h swall[$ 8 *ildr51 accord+ to ! leg5d4 ,he f9ally became s exasp]at$ ) ! results ( 8 obs]vations t he gave up obs]v+ ! planet4 ,! true nature ( ^! app5dages ( ,saturn rema9$ a my/]y until ,huyg5s solv$ ! problem 9 #afee1 "s "t aft] ! dea? ( ,galileo4 ,9 addition to ! r+s1 ,saturn has n9e satellites nam$1 9 ! ord] ( _! di/ance outw>d f ! planet1 ,mimas1 ,enceladus1 ,te?ys1 ,dione1 ,rhea1 ,titan1 ,hyp]ion1 ,iapetus & ,phoebe4 ,! la/-m5tion$ satellite 0 discov]$ by ,w4 ,h4 ,pick]+ 9 #ahii4 ,x ar\s$ great int]e/ at ! "t because x 0 ! fir/ satellite to be discov]$ ) retrograde motion 9 its orbit4 ,two satellites ( ,jupit] s9ce discov]$ revolve 9 ! same direction ar\nd _! prim>y4 ,! satellites ( ,saturn are approximate to ^? ( ,jupit] 9 size & exactly equal !m 9 numb]4 ,! l>ge/1 ,titan1 is ?ree ?\s& miles 9 diamet] & c be easily se5 ) ! smalle/ telescopes4 ,) a f\r-in* telescope five ( ! satellites c be readily f\nd1 ?\gh !y are n z int]e/+ to obs]ve z ! satellites ( ,jupit] because !y are f> m di/ant f ! e>?4 ,! "t !y require to make "o j\rney ar\nd ,saturn v>ies f ne>ly tw5ty-?ree h\rs = ,mimas1 ! ne>e/1 to approximately five hundr$ & tw5ty-f\r days = ,phoebe1 ! mo/ di/ant4 ,saturn z well z ,jupit] is m>k$ by belts p>allel to ! ,equator ?\gh !y appe> m indi/9ct ?an ^? ( ,jupit] on acc\nt ( ! great] di/ance ( ,saturn4 ,saturn also resembles ,jupit] 9 its physical composition :i* is l>gely1 if n entirely1 gase\s1 & 9 ! extremely %ort p]iod ( rotation on its axis :i* is approximately t5 h\rs4 ,9 m ways ?an "o ,saturn is a v unusual planet4 ,9 addition to possess+ an enorm\s r+ sy/em x is ! lighte/ ( all ! planets1 its d5sity be+ only sixty-?ree hundr$?s t ( wat]1 & x is ! mo/ oblate1 its flatt5+ at ! poles am\nt+ ne>ly to "o-t5? ( its diamet]4 ,its equator is m highly incl9$ to its orbit ?an is ! case ) any o!r planet1 n ev5 except+ ! e>? & ,m>s4 ,= ?is reason its seasonal *anges are v great1 9 m>k$ contra/ to ,jupit] ^: equator lies v ne>ly 9 ! plane ( its orbit4 ,s9ce ,saturn is s f> away f ! sun t x receives only "o n9etie? z mu* light & heat p] unit area z ! e>?1 its out] gase\s surface mu/ be extremely cold unless consid]able heat is convey$ to ! surface f )9 its hot int]ior4 ,! late ,pr(4 ,l[ell conclud$ f c]ta9 obs]vations made at ,flag/aff1 ,ariz41 t ,saturn is compos$ ( lay]s ( diff]5t d5sities & t ! inn] lay]s are m flatt5$ at ! poles & rotate fa/] ?an ! out] lay]s4 ,m>k$ v>iations 9 ! color & brightness ( ! ball ( ! planet h be5 not$ f "t to "t4 ,9 #aiaf obs]v]s ( ,saturn describ$ ! planet z p9ki%-br[n & conspicu\sly d>k] ?an ! bright] portions ( ! r+s4 ,x is believ$ t ^! v noticeable *anges 9 ! color & brightness ( ,saturn are due to slight1 irregul> *anges 9 ! int5sity ( ! radiations ( ! sun :i* set up c]ta9 second>y effects 9 ! atmosph]e ( ! planets4 ,simil> *anges 9 color & brightness h be5 obs]v$ also 9 ! case ( ,jupit]4 ,,xxi ,,is ,,! ,,moon ,a ,,dead ,,_w8 ,x has be5 a g5]ally accept$ belief among a/ronom]s = ye>s t ! moon is a dead _w devoid ( air & wat] & s1 necess>ily1 lifeless4 ,x is c]ta9 t ! moon has no ext5sive atmosph]e su* z envelops our own planet4 ,!re is abundant pro( ( ?is fact4 ,! edge ( ! lun> disk is cle>-cut4 ,:5ev]1 z happ5s frequ5tly1 ! moon passes betwe5 u & a /> ! disappe>ance ( ! /> is in/antane\s4 ,!re is no gradual dimm+ or refraction ( ! />'s light by atmosph]ic vapors4 ,moreov]1 lun> %ad[s are h>% & black4 ,!re is no evid5ce ( diffusion ( light on ! moon by atmosph]ic gases4 ,! abs5ce ( wat] or wat] vapor on ! visible surface ( ! moon1 at lea/ 9 any appreciable quantity1 is pla9ly evid5t to anyone :o obs]ves ! moon ?r\gh ! telescope4 ,ev5 ) small telescopes1 objects five miles or s 9 diamet] c be readily detect$ & cl\ds drift+ ov] ! surface c\ld n possibly escape our obs]vation if !y exi/$4 ,bodies ( wat]1 great or small1 w\ld be pla9ly visible & w\ld besides give rise to wat] vapor & cl\ds1 :i* we w\ld n fail to detect4 ,s9ce ! surface ( ! moon is unscre5$ by air & wat] vapor to absorb ! incom+ rays f ! sun1 & ! outgo+ radiations f ! surface1 ! extremes ( temp]ature betwe5 day & night are v great1 & are augm5t$ by ! fact t ! lun> day equals ! lun> mon? 9 l5g?1 s t f\rte5 days ( untemp]$ heat are foll[$ by f\rte5 days ( frigid d>kness4 ,obs]vations ( ! rate ( radiation f ! moon's surface dur+ total eclipses ( ! moon indicate t ! moon's radiation is v rapid1 & t its temp]ature dur+ ! height ( ! lun> day probably approa*es #bjj ,f41 :ile at ! lun> midnight x may h fall5 to #ajj bel[ z]o ,f41 or ev5 l[]4 ,) air & wat] bo? lack+ & su* extremes ( temp]ature exi/+ :y %\ld we s]i\sly consid] ! "q ( life on ! moon8 ,?is is ! po9t ( view ( ! majority ( a/ronom]s & x seems well tak54 ,yet _m a/ronom]s :o h made a special /udy ( ! lun> surface = ye>s "u all conditions ( illum9ation & phase1 & h mo/ c>efully obs]v$ & mapp$ & photograph$ its *>act]i/ic m>k+s1 are agre$ t !re are evid5ces t *anges are tak+ place on ! moon1 & rec5tly ,pr(4 ,w4 ,h4 ,pick]+ has express$ ! belief1 sub/antiat$ by draw+s1 t !re is a progressive *ange ( color or d>k5+ )9 c]ta9 lun> crat]s ) ! advance ( ! lun> day1 indicat+1 9 8 op9ion1 a rapid vegetational gr[? t spr+s up 9 ! height ( ! lun> day & dies out z ! lun> night approa*es4 ,"s ye>s ago c]ta9 sel5ograph]s sugge/$ t !re might exi/ 9 ! numb]less crat]-pits & crat]s1 9 ! deep-ly+ m>ia or seas1 & 9 ! clefts & rills & cracks t =m intricate sy/ems all ov] ! lun> surface1 c]ta9 exhalations f ! surface & heavy vapors includ+ possibly c>bon dioxide & wat] vapor to temp] ! extremes ( ! long lun> days & night & furni% ! necess>y m$ium = ! support ( c]ta9 =ms ( animal & vegetable life4 ,_m a/ronom]s1 includ+ a numb] :o are n 9 sympa?y ) ! above view1 believe t sn[ & ice exi/ on ! moon1 ev5 ?\gh wat] 9 ! =m ( liquid & vapor is n obs]vable4 ,all ! extremely brilliant portions ( ! surface1 accord+ to "s a/ronom]s1 are cov]$ ) sn[ & ice4 ,c]ta9ly1 "s portions ( ! moon's surface reflect sunlight z brilliantly z if !y 7 cov]$ ) fre%ly fall5 sn[1 :ile o!r portions appe> to be black by contra/4 ,!re also appe>s to be evid5ce t c]ta9 small m>k+s1 describ$ z crat]-cones & resembl+ our t]re/rial volcanoes m ?an any o!r lun> feature1 are at times tempor>ily obscur$ f view by a veil ( vapors4 ,_m obs]v]s believe t ^! crat]-cones are active volcanic v5ts1 & t !re is consid]able volcanic activity /ill tak+ place ^u ! moon4 ,^! small crat]-cones resemble1 we are told1 p>asitic cones f\nd on ! sides ( t]re/rial volcanoes1 & !y are frequ5tly se5 on ! floors ( crat]s closely associat$ ) light /reaks4 ,^! crat]-cones appe> "u a high sun z m9ute :ite spots & c be /udi$ to advantage only ) p[]ful in/rum5ts4 ,! ,italian a/ronom]1 ,magg9i1 obs]v+ ! floor ( ! lun> crat]1 ,plato1 9 #aiaf not$ t "o ( ! small crat]-cones t exi/ !re 9 great numb]s1 0 tempor>ily obscur$ f view by a cl\d ( r$di% vapors1 & ,pr(4 ,w4 ,h4 ,pick]+1 at ,arequipa1 ,p]u1 obs]v+ ! same region "s ye>s ago1 believ$ t he saw evid5ce ( *ange 9 "s ( ^! small m>k+s4 ,! crat]1 ,plato1 has probably be5 m c>efully /udi$ ?an any o!r portion ( ! lun> surface4 ,x is sixty miles 9 diamet] & may be se5 ev5 )\t a telescope z a d>k eye n f> f ! nor!rn edge ( ! moon4 ,its floor is "o ( ! d>ke/ objects 9 ! moon--a d>k /eel-grey 9 color--& !re is no d\bt t = "s unkn[n reason its d>k hue deep5s f ! "t ! sun has an altitude ( tw5ty degrees until aft] full moon4 ,x has a brilliant :ite wall ris+ f #c1jjj to #d1jjj feet above its floor1 cr[n$ ) sev]al l(ty peaks & int]sect$ by a numb] ( valleys & passes4 ,! spots & fa9t light m>k+s on ! floor h be5 ! object ( mu* /udy ) small or mod]ate siz$ in/rum5ts1 & at lea/ six ( !m are kn[n to be crat]-cones4 ,s9ce !y c only be /udi$ to advantage ) p[]ful in/rum5ts & z su* in/rum5ts are r>ely us$ = a sy/ematic /udy ( lun> m>k+s1 x is difficult to settle ! controv]sy z to :e!r !y h *ang$ 9 appe>ance or h be5 at any "t obscur$ by vapors4 ,mo/ lun> obs]v+ is done--necess>ily--) small] in/rum5ts because ! majority ( a/ronom]s appe> to h accept$ ! view t ! moon is a dead _w1 & ^? :o are engag$ 9 a/ronomical "w ) our greate/ telescopes seem to feel t o!r fields ( rese>* w prove m fruitful4 ,possibly x is = ?is reason t we "k s little ab\t our ne>e/ neighbor 9 space6 ,!re are at lea/ z _m unsolv$ problems confront+ u on ! moon z !re are among ! di/ant />s4 ,geologi/s tell u t m oxyg5 is to be f\nd 9 ! fir/ six feet ( ! e>?'s cru/ ?an 9 all ( ! atmosph]e above4 ,does oxyg5 n exi/ 9 ! surface rocks ( ! moon z well8 ,volcanic action1 we are told1 is prim>ily an escape ( gases f ! int]ior1 *iefly hydrog51 nitrog51 hydroc>bons1 sulphur1 & v>i\s comp\nds1 z well z va/ quantities ( /eam4 ,b5ea? ! surface *emical *ange is cont9ually tak+ place :i* results 9 ! release ( an enorm\s am\nt ( heat4 ,"s ( ! gases m5tion$ above comb9e ) ! oxyg5 9 ! surface rocks & heat is evolv$4 ,x is a kn[n fact t !re is great inh]5t heat 9 ! e>?'s surface cru/4 ,:y n 9 ! moon's surface cru/ z well8 ,! wat] t w\ld be expell$ 9 ! =m ( /eam f volcanic v5ts on ! moon w\ld be trans=m$ imm$iately into ho>-fro/1 sn[ & ice & w\ld settle d[n ^u ! flanks ( ! crat]-cones or v5ts4 ,x %\ld be borne 9 m9d t only volcanic activity on an enorm\s scale w\ld be pla9ly visible to u ev5 ) ! p[]ful telescopes at our comm&4 ,ord9>y eruptions su* z occur on our own planet w\ld be v difficult to detect4 ,s9ce ! escap+ vapors w\ld rapidly pass into ! solid /ate & settle d[n ^u ! flanks ( ! crat]-cones or v5ts1 we w\ld obs]ve 9 g5]al little if any *ange 9 an object unless we *anc$ to be look+ at x at ! "t ( ! eruption1 :5 x might appe> to be tempor>ily obscur$ by a veil ( vapors4 ,:at are ! *ances t we w\ld be c>efully obs]v+ at ! precise "t ( an eruption1 a m9ute m>k+1 two or ?ree miles 9 diamet]1 on a surface z l>ge z all ( ,nor? ,am]ica1 a surface t is cov]$ ) "s #cj1jjj *>t$ crat]s1 numb]less crat]-pits1 /reaks1 rays1 spots1 clefts & rills 9 intricate sy/ems1 m\nta9 *a9s & valleys & a mass ( intricate detail8 ,if we 7 look+ at ! e>? f ! moon ) ! aid ( a p[]ful telescope w\ld we be apt to notice an eruption ( ,vesuvius or ,katmai or ,mauna ,loa8 ,objects f\r or five miles 9 diamet] w\ld appe> z hazy spots ) no?+ di/9ctive or rem>kable 9 _! appe>ance4 ,yet vapor & /eam aris+ f t]re/rial volcanoes w\ld be c>ri$ by our atmosph]e ov] an area ( _m squ>e miles1 :ile !re is no atmosph]e on ! moon to spread ! vapors t may arise f simil> volcanic v5ts4 ,x w\ld h to be a cataclysmic *ange inde$ to be accept$ z indisputable evid5ce t *ange is tak+ place on ! moon1 & ! days ( gigantic upheavals are probably ov] on our satellite z well z on ! e>?4 ,if volcanic activity is /ill tak+ place on ! moon x is probably 9 a mild =m su* z a comp>atively quiet emission ( gases f volcanic v5ts & fum>oles4 ,su* =ms ( activity w\ld n be pla9ly visible at ?is di/ance1 ev5 ) ! aid ( p[]ful telescopes4 ,! problem ( detect+ *anges on ! moon is complicat$ by ! fact t a *ange ( illum9ation greatly alt]s ! appe>ance ( all lun> m>k+s4 ,su* a *ange is cont9ually tak+ place 9 ! c\rse ( ! mon?4 ,a m>k+ t /&s out 9 bold relief at lun> sunrise or sunset w *ange entirely 9 appe>ance a few days lat] "u a high sun or ev5 disappe> f view entirely4 ,^! *anges 9 phase or illum9ation h to be tak5 acc\nt ( 9 ! se>* = evid5ce ( actual *ange4 ,to decide :e!r or n *ange has actually tak5 place ! object mu/ be view$ "u simil> conditions1 s f> z !y c be obta9$4 ,ev5 :5 special c>e is tak5 9 ?is respect ! suspect$ evid5ce ( *ange is usually expla9$ away z due to diff]5ces 9 illum9ation or see+1 by ^? :o h n obs]v$ ! object !mselves & are n 9 sympa?y ) ! view t ! moon is any?+ b a dead _w4 ,z reg>ds ! "q ( life on ! moon1 x is int]e/+ to consid] ! facts br\ght out by inve/igations made by sci5ti/s connect$ ) ! ,geophysical ,laboratory ( ! ,c>negie ,in/itute 9 ! ,valley ( ,t5 ,?\s& ,smokes4 ,! volcanic activity !re takes ! =m ( eruptions f num]\s small v5ts or fum>oles & n9ety-n9e p] c5t4 ( ! emanations are wat] vapor4 ,x 0 obs]v$ t blue-gre5 algae 7 liv+ at ! edge ( active v5ts emitt+ ammonia comp\nds at a temp]ature ( #bab ,f4 ,!y 7 n f\nd1 h[ev]1 ne> v5ts f :i* ammonia comp\nds 7 n be+ emitt$4 ,if life exi/s "u su* conditions x is conceivable t suitable conditions = ! support ( c]ta9 =ms ( life1 animal z well z vegetable1 may be f\nd 9 l[-ly+ valleys & crevices & ^u ! floors ( crat]s1 :]e c]ta9 gases ess5tial to ! support ( life might be evolv$ f _m small volcanic v5ts & fum>oles4 ,_m !ories h be5 advanc$ to expla9 ! orig9 ( ! lun> crat]s :i* h no c\nt]p>t on our own planet4 ,!y are sauc]-l depressions 9 ! surface ( ! moon1 frequ5tly ( su* great size t an obs]v] /&+ 9 ! c5t] w\ld n be able to see ei!r side ( ! crat] ow+ to ! curvature ( ! moon's surface4 ,crat]s fifty1 sixty or "o hundr$ miles 9 diamet] are by no means uncommon1 :ile !re are ?\s&s betwe5 five & fifty miles 9 diamet]4 ,a *>act]i/ic feature ( _m crat]s is a c5tral peak1 & ! surr\nd+ walls are (t5 a mile or m high & 9 "s in/ances are symmetrically t]rac$4 ,new crat]s h be5 =m$ on ! sides or floors ( old crat]s1 & ^! are always m cle>-cut & %>p] 9 outl9es ?an ! old =mations1 & g5]ally mu* small]4 ,a numb] ( crat]s are surr\nd$ by a sy/em ( light /reaks or rays ( unkn[n orig9 t ext5d 9 "s in/ances to enorm\s di/ances on all sides ( ! crat]4 ,! mo/ conspicu\s sy/em is ! "o surr\nd+ ! lun> crat] ,ty*o ne> ! s\? pole ( ! moon4 ,! rays orig9at+ 9 ?is crat] ext5d 9 all directions = hundr$s ( miles )\t turn+ aside = any ob/ructions1 pass+ ov] m\nta9s1 crat]s & pla9s 9 _! c\rse 9 practically /raight l9es l spokes 9 a :eel4 ,?is ray sy/em ( ,ty*o is ! mo/ noticeable m>k+ on ! moon's surface at ! "t ( full moon4 ,z ^! /reaks ca/ no %ad[ !y are app>5tly cracks 9 ! surface t h fill$ up ) "s light-color$ mat]ial f bel[4 ,_! orig9 has nev] be5 satisfactorily expla9$4 ,z to ! orig9 ( ! lun> crat]s1 "s believe t !y 7 produc$ 9 pa/ ages by a bomb>dm5t ( ! lun> surface by huge meteoric masses2 b !re are _m objections to ?is !ory t we w n take up "h4 ,x is m g5]ally believ$ t ! lun> crat]s are a result ( volcanic activity on an enorm\s scale :i* took place on ! moon _m ages ago & :i* has n[ practically ceas$1 its only manife/ations n[ tak+ ! =m ( a quiet emission ( gases f small volcanic v5ts or fum>oles :i* exi/ all ov] ! lun> surface b :i* are to be f\nd 9 greate/ numb]s on ! floors & sides ( crat]s4 ,,xxii ,,comets ,! orbits ( comets are incl9$ at all angles to ea* o!r & to ! orbits ( ! planets :i*1 on ! o!r h&1 lie v ne>ly 9 ! same plane4 ,! l>g] memb]s ( ! sun's family1 ! planets & _! satellites1 revolve f we/ to ea/ ar\nd ! sun4 ,comets on ! contr>y frequ5tly retrograde or back ar\nd ! sun 9 ! opposite direction--f ea/ to we/4 ,! pa?s t ^! erratic visitors foll[ 9 _! j\rneys ar\nd ! sun be> n ! slighte/ resemblance to ! pa?s ( ! planets1 :i* are almo/ p]fect circles4 ,! orbits ( comets are ellipses t are greatly elongat$ or p>abolas4 ,if ! orbit is a p>abola ! comet makes "o & only "o visit to ! sun1 com+ f int]/ell> space & return+ !reto aft] a brief soj\rn )9 our sol> sy/em4 ,donati's comet ( #aheh1 "o ( ! greate/ comets ( ! n9ete5? c5tury1 _h a p]iod ( m ?an two ?\s& ye>s & its aphelion 7! po9t 9 its orbit f>!/ away f ! sun7 0 five times m di/ant ?an ! orbit ( ,neptune4 ,!re is1 h[ev]1 a class ( comets kn[n z p]iodic comets t h extremely %ort p]iods ( revolution ar\nd ! sun4 ,to ?is class belongs ,halley's comet ^: p]iod ( sev5ty-five ye>s exce$s t ( any o!r %ort p]iod comet4 ,encke's comet1 on ! o!r h&1 has a p]iod ( ?ree & a ?ird ye>s :i* is ! %orte/ comet>y p]iod kn[n4 ,mo/ ( ! p]iodic comets are inconspicu\s & only visible telescopically ev5 :5 comp>atively ne> to ! e>?4 ,halley's comet is ! only "o ( ?is class t lays any pret5sions to rem>kable size or brilliancy & x also is %[+ ! effects ( dis9tegration result+ f too frequ5t visits to ! sun4 ,comets are bodies ( great bulk or volume & small total mass4 ,_! tails1 :i* only develop 9 ! vic9ity ( ! sun1 are =m$ ( ! r>e/ gases1 & ! be/ vacuum t man c produce w\ld n be 9 z t5u\s a /ate z ! mat]ial exi/+ 9 ! tails ( comets4 ,!re are _m pro(s ( ! extreme t5uity ( comets4 ,! e>? has on a numb] ( occasions pass$ directly ?r\gh ! tails ( comets )\t exp]i5c+ ! slighte/ visible effects4 ,/>s %9e undimm$ 9 lu/] ev5 ?r\gh ! heads ( comets4 ,if ! e>? %\ld enc\nt] a comet head on x is d\btful if x w\ld exp]i5ce any?+ m s]i\s ?an a %[] ( meteors :i* w\ld be consum$ by friction ) ! e>?'s atmosph]e1 or a fall ( meteorites ov] a small area ( a few squ>e miles4 ,x is possible1 h[ev]1 t matt] 9 ! nucleus1 ! />-l cond5sation 9 ! head ( a comet1 may consi/ ( individual p>ticles weigh+ 9 "s in/ances a numb] ( tons1 surr\nd$ by a gase\s envelope & held toge!r by ! loose bonds ( _! mutual attraction4 ,if ! e>? %\ld enc\nt] ! nucleus ( a comet consid]able damage might be done ov] a portion ( ! e>?'s surface1 b ! *ances ( su* an occurr5ce are less ?an "o 9 a million4 ,s9ce ! total mass ( a comet is s small1 a close approa* to "o ( ! planets1 especially ,jupit]1 produces great *anges 9 ! =m ( ! comet's orbit1 ?\gh ! motion ( ! planet is n di/urb$ 9 ! slighte/ degree by ! enc\nt]4 ,! majority ( all ! %ort-p]iod comets h be5 captur$ by ,jupit]1 t is1 ! orig9al orbits h be5 s *ang$ by ! p]turbations produc$ by close approa*es to ! giant planet t _! aphelia1 or ! po9ts 9 _! orbits f>!/ f ! sun1 lie 9 ! vic9ity ( ,jupit]'s orbit4 ,sev]al ( ! o!r planets h also captur$ comets 9 ?is s5se1 & ! fact t ! aphelia ( a numb] ( comets are gr\p$ at c]ta9 def9ite int]vals beyond ! orbit ( ,neptune has be5 consid]$ by "s a/ronom]s to be an indication t !re are two or m additional planets 9 ! sol> sy/em revolv+ ar\nd ! sun at ^! di/ances4 ,! mo/ int]e/+ feature ( a comet is its *>act]i/ic tail :i* develops & increases 9 size & brilliancy z ! comet approa*es ! sun4 ,z ! tail is always turn$ away f ! sun x foll[s ! comet z x draws ne> ! sun & prec$es x z x dep>ts4 ,its orig9 is due1 x is believ$1 bo? to electrical repulsion & light-pressure act+ ^u m9ute p>ticles ( matt] 9 ! coma or head ( ! comet4 ,! curvature ( ! tail dep5ds ^u ! nature ( ! gases ( :i* x is compos$4 ,long1 /raight tails consi/ *iefly ( hydrog51 x has be5 f\nd1 curv$ tails ( hydroc>bons & %ort1 bu%y tails ( mixtures ( iron1 sodium & o!r metallic vapors4 ,at times ! same comet w h two or m tails ( diff]5t types4 ,s9ce ! mat]ial driv5 (f f ! nucleus or head ( a comet by electrical repulsion & light-pressure is nev] recov]$1 x is evid5t t comets are cont9ually dis9tegrat+4 ,also1 comets t h pass$ close to ! sun at p]ihelion h frequ5tly be5 s disrupt$ by tidal =ces t "o nucleus has sep>at$ into sev]al p>ts & ! newly =m$ nuclei h pursu$ pa?s p>allel to ! orig9al orbit1 ea* nucleus develop+ a tail ( its own4 ,_m p]iodic comets1 x is n[ kn[n1 h gradually be5 brok5 up & dissipat$ into p]iodic sw>ms ( meteors z a result ( ! disruptive effect produc$ by too frequ5t returns to ! vic9ity ( ! sun4 ,^! sw>ms ( meteors cont9ue to travel ar\nd ! sun 9 ! orbits ( ! =m] comets4 ,! e>? enc\nt]s a numb] ( su* sw>ms e ye> at c]ta9 def9ite times4 ,! l>ge/ & be/ kn[n ( ^! sw>ms or %[]s are ! ,leonids1 :i* appe> ab\t ,novemb] #ae2 ! ,&rom$as 7or ,bielids71 :i* appe> lat] 9 ! same mon? & ! ,p]seids1 :i* appe> e>ly 9 ,augu/4 ,^! sw>ms are nam$ = ! con/ellations 9 :i* _! radiant lies1 t is1 ! po9t 9 ! heav5s f :i* !y appe> to radiate4 ,! position ( ! radiant dep5ds ^u ! direction f :i* ! sw>m is com+4 ,x is simply a matt] ( p]spective t ! individual p>ticles appe> to radiate f ! "o po9t1 = !y are actually travell+ 9 p>allel l9es4 ,! lum9osity ( ^! meteoric p>ticles is caus$ by ! friction produc$ by _! passage ?r\gh ! atmosph]e4 ,!y always appe> noiselessly because !y are m]e p>ticles ( meteoric du/ weigh+ at ! mo/ sc>cely a gra94 ,!y diff] greatly 9 ?is respect f _! l>ge & noisy relatives1 ! meteorites1 bolides & fireballs4 ,numb]less small meteoric p>ticles are entrapp$ by ! e>?'s atmosph]e e day4 ,!y are ref]r$ to z %oot+ />s or fall+ />s ?\gh1 ( c\rse1 !y are n 9 any s5se />s4 ,x is only :5 ^! meteoric p>ticles travel 9 well-def9$ comet>y orbits & appe> at c]ta9 def9ite times e ye> t !y are ref]r$ to z sw>ms or %[]s ( meteors4 ,! lum9osity ( comets is due n only to reflect$ sunlight1 b to c]ta9 unkn[n causes t produce sudd5 & erratic increases or decreases ( brilliancy4 ,! causes ( ^! sudd5 *anges 9 lum9osity are unkn[n2 possibly electrical dis*>ges or *ance collisions betwe5 fragm5ts ( consid]able size may acc\nt = "s ( !m4 ,! peculi> behavior ( ! tails ( comets at c]ta9 times has frequ5tly be5 not$ & sugge/s ! exi/5ce ( quantities ( f9ely-divid$ meteoric or gase\s matt] )9 ! sol> sy/em t has no appreciable effect ^u ! huge planet>y masses1 b (f]s s5sible resi/ance to ! passage ( ! t5u\s gases ( :i* ! tails ( comets are compos$4 ,! fact t ! e>? daily enc\nt]s meteoric du/1 meteorites & fireballs also indicates t meteoric matt] exi/s 9 consid]able quantities )9 our sol> sy/em4 ,tails ( comets appe> at times to be twi/$ or bru%$ aside z if !y _h enc\nt]$ "s unkn[n =ce or "s resi/+ m$ium4 ,up to ! pres5t "t sev]al hundr$ comets h be5 discov]$4 ,ne>ly ?ree-f\r?s ( ?is numb] travel 9 orbits t appe> to be p>abolas4 ,( ! rema9+ numb] !re are ab\t =ty t h be5 captur$ by ! major planets1 ,jupit]1 ,saturn1 ,uranus & ,neptune1 ?\gh ,jupit] possesses ! lion's %>e ( ^! captur$ comets4 ,sc>cely a ye> passes by t sev]al comets are n discov]$4 ,mo/ ( ^! are telescopic1 h[ev]1 ev5 :5 !y are ne> ! sun & at _! greate/ brilliancy4 ,nak$-eye comets ( great spl5dor & brilliancy are comp>atively r>e & !re has be5 a p>ticul> de>? ( su* unusual comets dur+ ! pa/ ?irty ye>s or s4 ,! la/ spectacul> comet1 unless we make an exception ( ,halley's p]iodic comet1 :i* made its return accord+ to pr$iction 9 #aiaj1 0 ! great comet ( #ahhb :i* 0 visible 9 broad daylight close to ! sun & at its p]ihelion passage swept ?r\gh ! sol> corona ) a velocity t exce$$ two hundr$ & fifty miles a second & c>ri$ x ?r\gh "o hundr$ & eighty degrees ( its orbit 9 less ?an ?ree h\rs4 ,"s comets approa* mu* clos] to ! sun ?an o!rs4 ,! majority ( all comets obs]v$ h come )9 ! e>?'s orbit & no kn[n comet has its p]ihelion beyond ! orbit ( ,jupit]4 ,x is1 ( c\rse1 possible t !re may be a numb] ( comets t nev] come )9 ! orbit ( ,jupit]1 b x is v unlikely t any su* comet w\ld ev] be discov]$4 ,! majority ( comets are simply small1 fuzzy po9ts ( light t are only visible telescopically & ! great] ! p]ihelion di/ance ( ! comet ! less likely is x to be se5 ) ! nak$ eye4 ,s9ce comets z well z planets obey ,kepl]'s fir/ law1 kn[n z ! law ( areas1 & sweep ov] equal areas 9 equal times1 x is evid5t t :5 a comet is at p]ihelion1 or ne>e/ to ! sun1 x is mov+ at maximum spe$ & :5 x is at aphelion1 or f>!/ f ! sun1 x is mov+ at m9imum spe$4 ,moreov]1 its spe$ at ^! two po9ts 9 its orbit v>ies trem5d\sly s9ce ! orbits ( comets are ellipses ( v high ecc5tricity4 ,! spe$ ) :i* ! planets are travel+ is1 on ! o!r h&1 rem>kably uni=m s9ce _! orbits are ne>ly circul>4 ,! leisurely spe$ ) :i* a comet travels ?r\gh ! frigid out] regions ( ! sol> sy/em is gradually accel]at$ z ! comet draws ne>] & ne>] to ! sun until x has acquir$ ne> ! "t ( p]ihelion passage a velocity t occasionally exce$s two hundr$ miles a second4 ,"h1 also1 ! great increase 9 light & heat & ! /rong magnetic field ( ! sun produce complex *anges 9 ! gase\s & meteoric sub/ances ( :i* ! comet is compos$ until ! *>act]i/ic tail & peculi> comet>y features are fully develop$4 ,z ! comet aga9 rec$es f ! sun aft] p]ihelion passage its spe$ slack5s once m4 ,x soon p>ts ) its tail & o!r spectacul> features & fades rapidly f view ev5 9 ! l>ge/ telescopes4 ,,xxiii ,,meteorites ,meteorites1 bolides or fireballs1 z !y are v>i\sly call$1 are /ones t fall to ! e>? f ! heav5s4 ,!y furni% ! "o tangible evid5ce t we possess1 aside f t furni%$ by ! spectroscope1 z to ! composition ( o!r bodies 9 space & x is a significant fact t no unkn[n elem5ts h ev] be5 f\nd 9 meteorites1 ?\gh ! =ms 9 :i* !y appe> are s *>act]i/ic t !y make ^! /ones readily di/+ui%able f /ones ( t]re/rial orig94 ,! orig9 ( meteorites is n def9itely kn[n1 b ! evid5ce is v /rong 9 favor ( ! !ory t !y are ! l>g] fragm5ts ( dis9tegrat$ comets ( :i* meteors & %oot+ />s are ! small]2 ! di/9ction betwe5 ! two be+ simply t ! latt] class includes all bodies t are completely consum$ by friction ) ! e>?'s atmosph]e &1 !re=e1 only rea* ! surface 9 ! =m ( meteoric du/4 ,accord+ to o!r !ories meteorites may be fragm5ts ( %att]$ worlds t h *anc$ to come too ne> to a l>g] body & h be5 disrupt$1 or !y may possibly be ! l>g] fragm5ts ( ! dis9tegrat$ comets ( :i* ! meteoric sw>ms are ! small]4 ,int]planet>y space is n altoge!r a void4 ,our own planet sweeps up 9 ! c\rse ( a s+le day1 x has be5 e/imat$1 approximately tw5ty million %oot+ />s or meteors ( suffici5t size to be visible to ! nak$ eye1 :ile ! e/imate = ! telescopic p>ticles runs up to f\r hundr$ million4 ,meteorites on ! o!r h& are comp>atively r>e4 ,on ! av]age x has be5 e/imat$ ab\t "o hundr$ meteorites /rike ! e>? 9 ! c\rse ( a ye>1 ( :i* numb] only two or ?ree are actually se54 ,accord+ to ,bullet9 #id1 ,u4 ,s4 ,national ,museum1 approximately six hundr$ & fifty falls & f9ds ( meteorites h be5 report$1 repres5tatives ( :i* appe> 9 museums & private collections4 ,meteorites1 z well z %oot+ />s & meteors1 frequ5tly appe> 9 %[]s4 ,9 su* in/ances ! fall usually consi/s ( sev]al hundr$ or ?\s& individual /ones & ! area ov] :i* !y fall is sev]al squ>e miles 9 ext5t & r\ghly ellipsoidal 9 %ape4 ,"o ( ! mo/ rem>kable ( su* falls 444 hundr$ ?\s& /ones1 v>y+ 9 weight f fifte5 p\nds to a small fraction ( an ounce1 fell ne> ,pultusk1 ,pol&4 ,ano!r rem>kable fall ( meteorites occurr$ at ,l',aigle1 ,france1 9 #ahjc4 ,betwe5 two ?\s& & ?ree ?\s& /ones fell ov] an ellipsoidal area ( six & two-t5?s miles 9 greate/ diamet]1 ! aggregate weight ( ! /ones be+ n less ?an sev5ty-five p\nds4 ,?is fall ( /ones is ( p>ticul> int]e/ s9ce x took place at a "t :5 m5 7 /ill v d\btful z to :e!r or n /ones actually fell to e>? f ! heav5s4 ,aft] ?is fall _h occurr$ 9 a mo/ popul\s di/rict ( ,france 9 broad daylight & att5d$ by viol5t explosions t la/$ = five or six m9utes & 7 he>d = a di/ance ( sev5ty-five miles1 no reasonable d\bt c\ld long] be held z to ! actuality ( su* ph5om5a4 ,meteorites are )\t exception ( an igne\s nature1 t is1 !y are rocks t h solidifi$ f a molt5 condition4 ,!y c be classifi$ into ?ree gr\ps1 ,a]olites or ,/ony ,meteorites1 ,sid]olites or ,/ony-iron ,meteorites1 & ,sid]ites or ,iron ,meteorites4 ,m iron meteorites seem to h fall5 9 ,mexico & ,gre5l& ?an 9 any o!r "p ( ! _w--at lea/ ( its l& surface4 ,yet /range to say1 ( all ! meteorites t h be5 se5 to fall only n9e belong to ! gr\p ( ,sid]ites or ,iron ,meteorites1 ?\gh ! ?ree l>ge/ meteorites kn[n1 ,pe>y's meteorite f ,cape ,york1 ,gre5l&1 weigh+ #cg-a_/b tons1 ! meteorite ly+ on ! pla9 ne> ,bacubirito1 ,mexico1 weigh+ ab\t #bj tons1 & ! ,willamette1 ,oregon1 meteorite1 weigh+ #ae-a_/b tons all belong to ?is gr\p4 ,moreov]1 all ! ,canyon ,diablo meteorites1 :i* are /rewn conc5trically ar\nd ,coon ,m\nta9 crat] 9 nor!rn ,arizona to a di/ance ( ab\t five miles1 are memb]s ( ?is same gr\p4 ,coon ,m\nta9 or ,meteor crat] itself is a p]fectly r\nd hole1 ab\t six hundr$ feet deep & ov] f\r ?\s& feet 9 diamet] & 0 =m$1 x is believ$1 by ! impact ( a huge meteorite :i* has nev] be5 f\nd4 ,x is believ$ t ! ,canyon ,diablo meteorites1 ( :i* !re are ne>ly f\r hundr$ individuals 9 ! ,u4 ,s4 ,national ,museum alone1 7 all memb]s ( ?is same fall4 ,x is possible t ^! meteorites ( ! ,canyon ,diablo di/rict1 ) ! huge meteorite t produc$ ! crat] itself1 =m$ ! nucleus ( a comet t /ruck ! e>? n m ?an five ?\s& ye>s ago1 accord+ to ! geological evid5ce4 ,all iron meteorites or sid]ites 7f ! ,greek sid]os1 iron7 are compos$ *iefly ( alloys ( nickel & iron4 ,! p]c5tage ( nickel 9 ^! iron meteorites is v small1 usually f five to t5 p] c5t41 :ile ! iron =ms ab\t n9ety or n9ety-five p] c5t4 ( ! :ole4 ,cobalt is also pres5t 9 practically all iron meteorites 9 small quantities ( #a p] c5t4 or less4 ,usually small quantities ( iron sulphide & phosphide z well z graphite or "s o!r =m ( c>bon appe> 9 ! iron meteorites & 9 "s in/ances black & :ite diamonds h be5 f\nd1 z 9 "s ( ! ,canyon ,diablo irons4 ,a v int]e/+ & beautiful feature ( _m iron meteorites is ! ,widman/tt5 figures :i* appe> :5 a section ( su* a /one is poli%$ & treat$ by means ( a weak acid4 ,^! figures are due to ! unequal solubility ( ! ?ree diff]5t alloys ( nickel & iron ( :i* ! /ones are compos$4 ,! irons giv+ ! ,widman/tt5 figures are kn[n z octah$ral irons4 ,o!r irons kn[n z hexah$ral irons give figures ( a diff]5t type kn[n z ,neumann figures :5 ! poli%$ section is treat$ ) weak acid1 :ile o!r irons are s homog5e\s 9 _! composition t !y %[ no figures at all4 ,a]olites or ,/ony ,meteorites occur m abundantly ?an iron or /ony-iron types1 & !y are classifi$ into _m divisions & subdivisions accord+ to _! composition4 ,9 ^! /ones appe> c]ta9 comp\nds t are commonly met ) 9 t]re/rial igne\s rocks4 ,! m9]al t is mo/ abundant 9 ! /ony meteorites1 compos+ sometimes ne>ly sev5ty-five p] c5t4 ( ! /one1 is a magnesium & iron silicate kn[n z oliv9e1 :i* is also usually pres5t 9 t]re/rial rocks ( an igne\s nature4 ,c]ta9 comp\nds f\nd 9 ! /ony meteorites are r>ely if ev] f\nd 9 t]re/rial rocks1 h[ev]1 & ^! s]ve to di/+ui% ! /ony meteorites readily f /ones ( t]re/rial orig94 ,! alloys ( iron & nickel1 = in/ance1 t occur 9 m9or quantities 9 ! /ony meteorites & make up usually ab\t n9ety-five p] c5t4 ( ! mass ( ! iron meteorites1 are nev] f\nd 9 t]re/rial rocks4 ,al?\gh ab\t ?irty ( ! t]re/rial elem5ts are to be f\nd 9 meteorites1 ! =ms & comp\nds 9 :i* !y appe> are s *>act]i/ic & on ! :ole s diff]5t f ^? occurr+ 9 t]re/rial rocks1 t ! analy/ has no difficulty 9 di/+ui%+ betwe5 ! two4 ,!re are1 = in/ance c]ta9 =mations kn[n z *ondrules1 peculi> sph]ical & oval %apes1 v>y+ 9 size f m9ute p>ticles to objects ! size ( walnuts1 appe>+ 9 _m v>ieties ( /ony meteorites t are nev] f\nd 9 t]re/rial rocks1 & t are "o ( ! mo/ puzzl+ features associat$ ) ! orig9 & nature ( ^! /ones4 ,sometimes ! *ondrules are s loosely emb$d$ 9 ! /one t !y fall away :5 x is brok54 ,9 "s in/ances almo/ ! entire /one is made up ( ^! *ondrules4 ,accord+ to "o !ory ! *ondrules 7 orig9ally molt5 drops1 l fi]y ra91 & _! int]nal /ructure1 :i* is greatly v>i$1 dep5ds ^u _! conditions ( cool+4 ,/ony meteorites1 9 :i* ^! *ondrules are to be f\nd1 are spok5 ( z *ondrites4 ,!re are :ite & gray & black *ondrites & cry/all9e & c>bonace\s *ondrites1 accord+ to ! nature ( ! *ondrules f\nd 9 ! /ones4 ,/ony meteorites also conta9 m9ute quantities ( iron & nickel alloys 9 ! =m ( drops or /r+]s4 ,^u ent]+ ! e>?'s atmosph]e /ony meteorites become coat$ ) a ?9 black cru/ :i* is a glass =m$ by ! fusion ( its surface mat]ials by ! heat g5]at$ dur+ its passage ?r\gh ! atmosph]e4 ,9 _m ( ! /ony meteorites !re also appe> f9e ?read-l ve9s :i* are due to ! fractur+ ( ! /one prior to its entrance into ! atmosph]e4 ,! mat]ial fill+ ^! ve9s is coal black 9 color1 opaque & ( an unkn[n composition4 ,_m meteorites %[ signs ( collisions & enc\nt]s ) o!r meteorites outside ( ! atmosph]e z w\ld be expect$ z !y travel 9 sw>ms & gr\ps4 ,sometimes ! entire meteorite is compos$ ( fragm5ts ( two or m di/9ct /ones cem5t$ toge!r4 ,su* a /one is spok5 ( z a breccia4 ,9 ! ?ird class ( meteorites to :i* we n[ come1 kn[n z ! /ony-iron meteorites1 !re is a network or sponge ( nickel-iron alloy1 ! int]/ices ( :i* are fill$ ) /ony mat]ial4 ,:5 ?is network or sponge is cont9u\s ! meteorite is spok5 ( z a /ony-iron pallasite4 ,:5 ! network ( metal is m or less disconnect$ ! meteorite is a meso-sid]ite4 ,if meteorites are heat$ 9 a vacuum1 ! conditions exi/+ 9 int]planet>y space be+ ?us produc$ to a c]ta9 ext5t1 !y give =? _! occlud$ gases & x has be5 f\nd t ^! gases give spectra id5tical ) ! spectra ( c]ta9 comets4 ,meteoric irons give =? hydrog5 z _! *>act]i/ic gas :ile ! gases occlud$ 9 ! /ony meteorites are *iefly ! oxides ( c>bon1 c>bon monoxide & c>bon dioxide4 ,x has be5 f\nd t ! am\nt ( gases conta9$ 9 a l>ge meteorite or %[] ( meteorites is suffici5t to =m ! tail ( a comet4 ,^! facts all t5d to /r5g!n ! belief t meteorites are inde$ comet>y fragm5ts4 ,9 view ( ! fact t "s geologi/s believe meteorites may be fragm5ts ( o!r worlds1 x is ( int]e/ to "k t s f> no fossil-be>+ meteorites h be5 f\nd1 & if meteorites are fragm5ts ( a %att]$ _w1 su* worlds mu/ h be5 r$uc$ to a molt5 condition at ! "t ( ! cata/rophe4 ,! rapid passage ( ! meteorite ?r\gh ! air leaves a p>tial vacuum 9 its trail into :i* ru% ! molecules ( air f all sides1 produc+ ! *>act]i/ic noises t accompany ! passage ( a meteorite1 :i* h be5 v>i\sly comp>$ to ! rattle ( artill]y1 ! di/ant boom+ ( cannons or ! rumble ( ?und]4 ,!re may be1 also1 explosions ( inflammable gases occlud$ 9 ! crevices ( ! meteorite :i* w %att] x into fragm5ts or ! meteorite may be %att]$ by ! resi/ance & pressure ( ! atmosph]e or z a result ( ! extremes ( temp]ature exi/+ betwe5 ! int]ior & its surface4 ,_m meteorites h actually be5 se5 to bur/ into fragm5ts 9 ! air ) a l\d report4 ,!re is practically no f\ndation = ! belief t g]ms ( life h be5 br\ght to our planet on su* igne\s rocks4 ,no microscopic exam9ations ( meteorites h yield$ any results t c\ld be int]pret$ 9 favor ( su* a view4 ,falls ( meteorites are accompani$ 9 ne>ly e in/ance by t]rific explosions & %>p reports t c be he>d = _m miles ar\nd1 (t5 caus+ ! gr\nd to %ake z 9 an e>?quake4 ,! meteorite itself has be5 describ$ z resembl+ a ball ( fire or ! headlight ( a locomotive1 & is foll[$ frequ5tly by a trail ( light or a cl\d ( smoke4 ,at ! "t x ent]s our atmosph]e a meteorite is mov+ ) planet>y velocity rang+ f two to =ty-five miles p] second4 ,its int]ior is int5sely cold1 approa*+ 9 temp]ature ! absolute z]o ( int]planet>y space1 & x is1 !re=e1 f> m brittle ?an x w\ld be at ord9>y temp]atures4 ,z x pl\ghs its way into ! e>?'s atmosph]e its surface temp]ature is soon rais$ by friction to at lea/ #c1jjj or #d1jjj ,c41 :i* is suffici5t to fuse all surface mat]ials into ! *>act]i/ic black cru/1 ) :i* /ony meteorites are coat$4 ,meteorites are usually fir/ se5 at an altitude ( fifty or sixty miles4 ,al?\gh !y are mov+ ) a velocity comp>able to t ( ! planets1 :5 !y ent] ! e>?'s atmosph]e1 ?is velocity is s rapidly r$uc$ by friction ) ! atmosph]e t !y usually drop to ! surface ( ! e>? ) a velocity ab\t equal to t ( ord9>y fall+ objects4 ,! flight ( a meteorite (t5 ext5ds ov] a pa? sev]al hundr$ miles 9 l5g? & ! meteorite may be se5 by _m obs]v]s 9 sev]al diff]5t ,/ates & yet f9ally fall 9 "s unkn[n spot & nev] be f\nd4 ,! evid5ce ga!r$ reg>d+ ! actual fall ( meteorites is (t5 contradictory4 ,"s /ones are too hot to h&le = h\rs aft] !y fall1 o!rs are m]ely w>m1 :ile /ill o!rs h be5 pick$ up cool or ev5 int5sely cold4 ,meteorites h be5 se5 to fall ^u dri$ grass & ^u /raw )\t produc+ ev5 *>r+ effects4 ,! evid5ce reg>d+ ! dep?s to :i* meteorites p5etrate ! gr\nd is q z conflict+4 ,! l>ge/ ( all ! /ony meteorites :i* fell at ,krnyah9ya1 ,hung>y1 weigh$ #fdg p\nds & buri$ itself to a dep? ( elev5 feet4 ,yet ,pe>y's ,cape ,york iron meteorite1 weigh+ #cg-a_/b tons1 0 only p>tially cov]$ & %[$ no signs ( abrasions ( surface result+ f ! fall4 ,! ,willamette iron meteorite1 weigh+ #af-a_/b tons1 lay 9 a =e/ :5 f\nd & 0 n deeply buri$4 ,! ,bacubirito iron meteorite1 weigh+ #bj tons1 lay 9 s(t soil1 b>ely b5ea? ! level ( ! surface4 ,on ! o!r h& a fragm5t ( a /ony-iron meteorite1 weigh+ #dcg p\nds1 t fell at ,e/h]ville1 ,i[a1 buri$ itself eight feet 9 /iff clay4 ,geologi/s 9 *>ge ( ! meteoric collections ( v>i\s museums q frequ5tly h /ones s5t to !m = analysis t are reput$ to be ( cele/ial orig94 ,m (t5 ?an n su* /ones are f\nd to be purely t]re/rial 9 _! orig94 ,! composition ( a meteorite is s *>act]i/ic & unique t su* a /one c nev] be mi/ak54 ,f9ds ( bona-fide meteorites are on ! :ole extremely r>e4 ,x is also a peculi> fact t meteorites are usually obs]v$ 9 ! mon?s :5 ord9>y meteors or p]iodic sw>ms ( meteors are lea/ preval5t1 t is 9 ! mon?s ( ,may1 ,june & ,july4 ,,xxiv ,,! ,,e>? ,,z ,a ,,magnet ,if a small1 freely susp5d$ compass ne$le is mov$ ov] a highly magnetiz$ /eel sph]e1 x w be se5 t x con/antly *anges its position bo? horizontally & v]tically s z to lie always along ! l9es ( =ce ( ! sph]e4 ,!re w be "o po9t on ! sph]e :i* we w call ! ,nor? ,magnetic ,pole1 :]e ! nor?-seek+ end ( ! ne$le w po9t v]tically d[nw>d or make a dip ( #ij ) ! tang5t plane4 ,at ! diametrically opposite po9t on ! sph]e1 call$ ! ,s\? ,magnetic ,pole1 ! opposite end ( ! compass1 ! s\?-seek+ end1 w po9t v]tically d[nw>d2 :ile at a po9t midway betwe5 ! magnetic poles ( ! sph]e ! ne$le w lie p>allel to ! diamet] connect+ ! two poles & !re w be no dip4 ,! total int5sity ( ! magnetic field surr\nd+ ! sph]e w be f\nd to be greate/ 9 ! vic9ity ( ! magnetic poles & lea/1 midway betwe5 ! poles4 ,n[1 a freely susp5d$ compass ne$le c>ri$ to all p>ts ( ! e>? w behave v mu* 9 ! same mann] z ! ne$le mov$ ov] ! magnetiz$ /eel sph]e4 ,!re are two po9ts on ! e>?'s surface1 kn[n z ! ,nor? & ,s\? ,magnetic ,poles1 :]e ! ne$le po9ts v]tically d[nw>d & approximately midway betwe5 is ! ,magnetic ,equator :]e ! compass ne$le places itself 9 a p]fectly horizontal position & ! dip ( ! ne$le is z]o4 ,9 o!r words1 ! e>? acts z a huge magnet & possesses a magnetic field ) l9es ( =ce conv]g+ t[>ds its poles simil> to ! l9es ( =ce ( ! /eel sph]e4 ,!re are1 h[ev]1 "s v important diff]5ces betwe5 ! sph]e ( /eel & our e>?4 ,! matt] ( :i* ! e>? is compos$ is n homog5e\s4 ,x is believ$ to possess an iron core ( consid]able size1 x is true1 b its out] %ell is compos$ ( het]og5e\s masses t 9 c]ta9 regions cause v appreciable local deflections ( ! ne$le4 ,x is surr\nd$1 moreov]1 by an atmosph]e p]meat$ by electrifi$ p>ticles ( matt] %ot =? f ! sun1 :i* we n[ "k is a /ill great] magnet surr\nd$ by a magnetic field t is ( ! ord] ( #ej gausses at ! poles & ab\t eighty times m p[]ful ?an t ( ! e>?4 ,x is n[ a well-e/abli%$ fact t ! sun's magnetic field ex]ts a p[]ful influ5ce ov] ! condition ( ! e>?'s magnetic field1 & t va/ sol> di/urbances affect v mat]ially ! direction & int5sity ( ! l9es ( =ce4 ,x is ?us little wond] t ?is non-homog5e\s & rapidly rotat+ t]re/rial globe1 surr\nd$ by an electrifi$ atmosph]e & subject to ! action ( a /ill m p[]ful magnet1 ! sun1 %\ld n behave 9 a mann] exactly analog\s to a uni=mly magnetiz$ /eel sph]e4 ,! e>?'s magnetic poles are nei!r symmetrically plac$ nor absolutely fix$ 9 position4 ,!re is e reason to suspect t !y %ift ab\t f ye> to ye>1 & possibly fluctuate irregul>ly 9 position 9 ! c\rse ( a few days or h\rs "u ! influ5ce ( di/urb+ =ces4 ,! position ( ! e>?'s ,nor? ,magnetic ,pole1 la/ visit$ by ,amunds5 9 #aijc1 n[ lies approximately 9 ,latitude #gj ,n4 ,longitude #ig ,w4 ,! position ( ! ,s\? ,magnetic ,pole1 accord+ to ! late/ det]m9ations1 is1 9 r\nd numb]s1 9 ,latitude #gc ,s4 & ,longitude #aef ,e4 ( ,gre5wi*4 ,x is evid5t1 !re=e1 t ! magnetic poles ( ! e>? are n symmetrically plac$ & t !y lie fully #cj f ! geographical poles4 ,! *ord connect+ ! magnetic poles passes #gej miles f ! e>?'s c5t]1 & x is ab\t #a1bjj miles f ! geographic pole to ! ne>e/ magnetic pole4 ,!re exi/1 moreov]1 9 high latitudes local magnetic poles1 due possibly to heavy local deposits ( ore4 ,"o su* pole 0 discov]$ at ,cape ,treadwell1 ne> ,juneau1 ,alaska1 dur+ ,dr4 ,l4 ,a4 ,bau]'s obs]vations !re 9 #aijj & #aijg4 ,9 ! c5t] ( ! obs]v+ t5t at ?is po9t ! ne$le po9t$ v]tically d[nw>d & ! compass rev]s$ its direction :5 c>ri$ f "o side ( ! t5t to ! o!r4 ,x is a well-kn[n fact t !re are v few po9ts on ! e>?'s surface :]e ! compass ne$le po9ts ei!r to ! true geographical pole or to ! magnetic pole1 & if x does *ance to d s1 x is a transi5t happ5+4 ,! v>iation ( ! compass or ! decl9ation ( ! ne$le1 z x is call$1 is ! angle t ! compass ne$le makes ) ! true nor? & s\? l9e or ! m]idian4 ,x is an angle ( greate/ importance to navigators & explor]s1 = x gives !m _! be>+s1 yet x is un=tunately subject to ceaseless v>iations ( a mo/ complicat$ nature1 s9ce x dep5ds on ! con/antly pulsat+ & nev] ceas+ magnetic *anges t sweep ov] ! surface ( ! e>? & ?r\gh its cru/4 ,x is affect$ by long p]iod or secul> *anges1 z !y are call$1 progress+ m or less regul>ly 9 obscure cycles ( unkn[n p]iod4 ,x is subject to a diurnal *ange t dep5ds on ! position ( ! sun relative to ! m]idian1 & t v>ies ) ! seasons & ) ! h\r ( ! day4 ,x is affect$ by ! sun spot cycle ( #aa4c ye>s :i* has a direct effect ^u ! int5sity ( ! e>?'s magnetic field4 ,! int5sity ( ! magnetic field 9 sun spots is1 accord+ to ,abbot1 sometimes z high z #d1ejj gausses or #i1jjj times ! int5sity ( ! e>?'s field4 ,at times ( maximum spott$ness ( ! sun ! int5sity ( ! e>?'s magnetic field is r$uc$4 ,moreov]1 :5 great & rapidly *ang+ spots appe> ^u ! sun1 electrifi$ p>ticles are %ot =? f ! sun ) great velocity & 9 great numb]s1 & are drawn 9 t[>ds ! magnetic poles ( ! e>?4 ,meet+ ! r>efi$ gases ( ! e>?'s upp] atmosph]e1 !y illum9ate !m z electric dis*>ges illum9ate a vacuum tube4 ,"s ( ^! electrons are absorb$ by gases at high elevations1 o!r desc5d to l[] levels4 ,! mo/ p5etrat+ rays h be5 kn[n to desc5d to an altitude ( tw5ty-five miles :i* is ab\t ! l[e/ limit yet f\nd = auroral displays4 ,x is ! passage ( ^! rays ?r\gh ! atmosph]e t cause ! magnetic di/urbances kn[n z magnetic /orms1 t are associat$ ) ! appe>ance ( great sun spots & auroral displays4 ,at su* times sudd5 *anges take place 9 ! int5sity ( ! e>?'s magnetic field t cause ! compass ne$le to %iv] & tremble & tempor>ily lose its directive value4 ,^! magnetic /orms h be5 kn[n to produce great temporal *anges 9 ! int5sity ( ! e>?'s field4 ,accord+ to ,dr4 ,l4 ,a4 ,bau]1 ,director ( ! ,dep>tm5t ( ,t]re/rial ,magnetism ( ! ,c>negie ,in/itute ( ,wa%+ton1 ! e>?'s int5sity ( magnetization 0 alt]$ by ab\t "o-tw5tie? or "o-?irtie? "p by ! magnetic /orm ( ,septemb] #be1 #aiji1 :i* 0 "o ( ! mo/ rem>kable on record1 & ! e>?'s magnetic condition 0 bel[ p> = fully ?ree mon?s aft]w>ds z a result4 ,9 addition to ^! v>i\s regul> & irregul> *anges 9 ! v>iation ( ! compass1 or decl9ation ( ! ne$le1 due to *anges 9 ! e>?'s magnetic field z a :ole1 !re are local effects due to re/rict$ regional di/urbances ( ! e>?'s magnetic field or to local deposits ( ore1 or to volcanoes or o!r local causes4 ,! effect ( all ^! di/urbances ^u ! decl9ation ( ! ne$le mu/ be det]m9$ by cont9ual magnetic surveys ( all portions ( ! e>?'s surface4 ,z a :ole ! e>?'s magnetic field is m uni=m ov] ! oceans ?an ov] ! l&1 ) all its di/urb+ topographical features4 ,yet ?is advantage is (fset l>gely 9 navigation by ! fact t e /eel %ip t sails ! seas is a magnet1 ) its two magnetic poles & its neutral l9e :]e ! two opposite magnetic =ces are neutraliz$1 z is ! case ) e magnet4 ,! direction 9 :i* a /eel %ip lies ) ref]5ce to ! e>?'s magnetic field :ile x is be+ built det]m9es ! position ( ! magnetic poles 9 its hull & ! position ( its neutral l9e & ?is di/ribution ( magnetism ov] a %ip's hull mu/ be tak5 acc\nt ( 9 ! in/allation ( its /&>d compass4 ,e piece ( horizontal & v]tical iron abo>d %ip has an effect ^u ! v>iation ( ! compass & comp5sation mu/ be made = su* di/urb+ =ces4 ,! direction ( sail+1 ! position 9 :i* a %ip lies at dock1 /orms enc\nt]$ at sea1 ! fir+ ( batt]ies 7on w>%ips7 are "s ( ! factors t are op]ative 9 produc+ *anges 9 ! v>iation ( ! magnetic compass abo>d a %ip4 ,e %ip mu/ und]go at frequ5t int]vals magnetic surveys = ! purpose ( det]m9+ its magnetic con/ants & its ,table ( ,deviations ( ! ,compass4 ,! direction 9 :i* ! compass ne$le po9ts abo>d %ip is ! resultant ( ! effect ( ! e>?'s magnetic field & ! magnetic field ( ! %ip1 & bo? fields are subject to cont9ual & complicat$ v>iations f ye> to ye>1 f day to day1 & ev5 f h\r to h\r6 ,! elem5ts ( ! e>?'s magnetic field are det]m9$ = any "o epo* by long-cont9u$ magnetic surveys c>ri$ on to a great] or less ext5t by ! v>i\s nations ( ! _w1 & ! results are publi%$ 9 ! =m ( magnetic *>ts = l& & sea1 %[+ ! values ( ! ?ree magnetic elem5ts1 decl9ation ( ! ne$le1 dip or incl9ation1 & horizontal int5sity ( ! e>?'s field = a def9ite p]iod4 ,s rapid are ev5 ! long-p]iod *anges 9 ! e>?'s magnetic field t a magnetic *>t c be reli$ ^u = only a v few ye>s & fre% data = ! con/ruction ( ^! *>ts t are s valuable to navigators & explor]s mu/ be ga!r$ cont9ually4 ,! ,dep>tm5t ( ,t]re/rial ,magnetism ( ! ,c>negie ,in/itute ( ,wa%+ton is engag$ 9 cont9ual magnetic surveys ( ! e>? by l& & sea t are ( ! highe/ value n only to navigators b also to sci5ti/s int]e/$ 9 solv+ ! great & my/]i\s problem ( ! und]ly+ causes ( ! e>?'s magnetism4 ,to give an idea ( ! ext5t & scope ( ! "w ( ?is dep>tm5t x may be m5tion$ t its non-magnetic %ip ,c>negie made 9 ! p]iod #aiji-aiah a total run ( #ahi1agf nautical miles1 ne>ly n9e times ! e>?'s circumf]5ce1 ) an av]age day's run ( #aai nautical miles4 ,magnetic obs]vations 7 made practically e day at a di/ance ( #ajj to #aej miles ap>t4 ,9 ?is n9e-ye> p]iod five cruises 7 made4 ,on h] fir/ cruise ! ,c>negie sail$ f ,/4 ,john's1 ,newf\ndl&1 to ,falm\?1 ,engl&1 ov] practically ! same c\rse foll[$ by ! fam\s a/ronom]1 ,halley1 9 ! ,p>am\r ,p9k two c5turies e>li] to det]m9e ! v>iation ( ! compass4 ,9 h] f\r? voyage ! ,c>negie circumnavigat$ ! _w 9 sub-ant>ctic regions 9 #aah days--a record "t4 ,%e has trav]s$ all oceans f #hj ,nor? to ! p>allel ( #fj ,s\? & has cross$ & recross$ h] own pa? & ! pa? ( h] pr$ecessor1 ! ,galilee1 _m times1 ?us mak+ x possible to det]m9e = ! po9ts ( int]section ! secul> *anges 9 ! magnetic elem5ts4 ,aft] a ?or\gh ov]haul+ 9 #aiai & ! in/allation ( a f\r-cyl9d] gasol9e eng9e1 made ( bronze ?r\gh\t1 to take ! place ( ! produc]-gas eng9e us$ on e>li] cruises1 ! ,c>negie />t$ on h] six? cruise ) a crew ( tw5ty-?ree (fic]s & m5 on ,octob] #i1 #aiai4 ,a cruise ( #fa1ejj miles 0 plann$ 9 ! ,s\? ,atlantic1 ,indian & ,pacific ,oceans to la/ approximately two ye>s4 ,unsurvey$ regions 9 ! ,s\? ,atlantic & ,indian ,ocean 7 to be cov]$ & ! r\te 0 plann$ s z to obta9 a l>ge numb] ( obs]vations ( ! progressive *anges t h tak5 place 9 ! magnetic elem5ts4 ,?is is accompli%$ z /at$ above by int]sect+ =m] r\tes & obta9+ new values ( ! elem5t at ! po9ts ( int]section4 ,9 addition to its ocean magnetic surveys ! ,dep>tm5t ( ,t]re/rial ,magnetism also c>ries on ext5sive l& surveys 9 all p>ts ( ! globe4 ,9 #aiai special exp$itions 7 s5t out by ! ,dep>tm5t to obs]ve ! total sol> eclipse ( ,may #bi? at /ations di/ribut$ ov] ! entire zone ( visibility ( ! eclipse & imm$iately outside4 ,at ,dr4 ,bau]'s /ation 9 ,lib]ia ! total phase 0 visible 9 a cl\dless sky = m ?an six m9utes1 :i* is v close to ! maximum l5g? ( phase t c possibly be obs]v$4 ,unmi/akable evid5ce 0 ga!r$ at all /ations ( an appreciable v>iation 9 ! e>?'s magnetic field dur+ a sol> eclipse1 :i* v>iation is ! rev]se ( t caus+ ! daylight portion ( ! sol> diurnal v>iation ( ! ne$le4 ,9 addition to ! magnetic survey "w on l& & sea :i* is ! *ief "w ( ! ,dep>tm5t ( ,t]re/rial ,magnetism1 atmosph]ic-electric obs]vations are c>ri$ on cont9ually on l& & sea & exp]im5ts h be5 c>ri$ on at ,langley ,field1 ,va41 lately1 9 ! developm5t ( me?ods & in/rum5ts = det]m9+ ! geographical position ( airplanes by a/ronomical obs]vations4 ,!re has also be5 rec5tly =m$ "u ?is dep>tm5t a ,section ( ,t]re/rial ,electricity4 ,! cause ( ! e>?'s magnetic field is /ill "o ( ! greate/ unsolv$ problems ( a/ro-physics4 ,! !ory t has be5 advanc$ by ,s*u/] t all l>ge rotat+ masses are magnets z a result ( _! rotation has receiv$ consid]able att5tion f a/rophysici/s1 & attempts h be5 made to prove ?is exp]im5tally4 ,x has be5 f\nd t iron globes spun at high velocities 9 ! laboratory d n exhibit magnetic prop]ties4 ,?is may mean simply t ! magnetic field is too weak to be detect$ 9 ! case ( a comp>atively small iron sph]e spun = a limit$ p]iod "u laboratory conditions4 ,x mu/ be rememb]$ t ! e>? has be5 rotat+ rapidly on its axis = millions ( ye>s & is1 comp>$ to t]re/rial objects1 an extremely l>ge mass4 ,yet x has be5 %[n t z a :ole our e>? is an extremely weak magnet1 & t if x 7 made entirely ( /eel & magnetiz$ z highly z an ord9>y /eel-b> magnet1 ! magnetic =ces at its surface w\ld be a ?\s& times great] ?an !y actually are4 ,if x is true t all rotat+ bodies are magnets1 !n all ! heav5ly bodies1 planets1 suns & nebul are surr\nd$ by magnetic fields4 ,we "k no?+ to ! contr>y4 ,9 fact1 we "k ?is to be true = ! e>? & sun1 & /rongly suspect t x is s 9 ! case ( ! planets ,jupit] & ,saturn4 ,:5 we und]/& m ab\t ! prop]ties ( matt]1 ! nature ( magnetism1 z well z ( gravity1 may be reveal$ to u4 ,,xxv ,,"s ,,effects ,,( ,,! ,,e>?',s ,,atmosph]e ,,^u ,,sunlight ,x is impossible to exagg]ate ! importance ( ! atmosph]e to all =ms ( life ^u ! surface ( ! e>?4 ,if !re 7 no atmosph]e !re w\ld be no life1 because x is ?r\gh ! ag5cy ( ! wat]-vapor1 c>bon-dioxide & oxyg5 9 ! atmosph]e t all life-processes are ma9ta9$4 ,if !re 7 no atmosph]e !re w\ld n only be no life ^u ! e>?2 !re w\ld be also none ( ! beautiful color effects produc$ by ! passage ( sunlight ?r\gh ! atmosph]e4 ,!re w\ld be no blue skies1 no beautiful sunrise & sunset effects1 no twilight1 no ra9b[s1 no halos1 no auroral displays1 no cl\ds1 no ra9s1 no riv]s nor seas1 no w9ds nor /orms4 ,! heav5s w\ld be p]fectly black except 9 ! direction ( ! heav5ly bodies :i* w\ld %9e z brilliantly by day z by night4 ,to und]/& h[ ! atmosph]e produces color effects su* z blue skies1 sunrise & sunset t9ts1 ra9b[s & halos1 z well z ! tw9kl+ ( ! />s1 & num]\s o!r ph5om5a1 we mu/ "k some?+ ( ! nature ( light itself4 ,light moves outw>d f any s\rce1 su* z ! sun1 9 all directions radially1 or along /raight l9es 7s long z x does n enc\nt] a gravitational field7 ) ! unimag9able velocity ( #ahf1jjj miles p] second4 ,z x advances x vibrates or oscillates back & =? across its pa? 9 all directions at "r angles to ?is pa?1 unless x is plane pol>iz$ light1 9 :i* case its vibrations are conf9$ to "o plane only4 ,^! vibrations or oscillations ( light take ! =m ( a wavelike motion1 "o wave-l5g? be+ ! di/ance pass$ ov] 9 ! "t ( "o vibration1 measur$ f cre/ to cre/ or f tr\gh to tr\gh ( adjac5t waves4 ,we may consid] t a beam or ray ( sunlight is made up ( a great numb] ( individual rays ( diff]5t wave-l5g?s & diff]5t colors4 ,! av]age wave-l5g? ( light1 ! wave-l5g? ( ! gre5 ray 9 sunlight1 is ab\t "o-fifty-?\s&? "p ( an in*1 t is1 x w\ld take ab\t fifty-?\s& wave-l5g?s ( gre5 light to cov] a space ( "o in*4 ,n[1 s9ce light makes "o vibration 9 pass+ ov] a di/ance ( "o wave-l5g?1 x makes fifty ?\s& vibrations1 :ile advanc+ "o in*1 & s9ce x advances "o hundr$ & eighty-six ?\s& miles 9 "o second we c easily figure out t a ray ( sunlight ( av]age wave-l5g? makes ab\t six hundr$ trillion vibrations 7#fjj1jjj1jjj1jjj1jjj7 9 a s+le second6 ,! *ief colors ( :i* sunlight or :ite light is compos$ are r$1 orange1 yell[1 gre51 blue1 indigo & violet1 ?\gh !re are an inf9ite numb] ( gradations ( color :i* bl5d into "o ano!r1 gradually produc+ ! int]m$iate t9ts & %ades4 ,! colors j m5tion$ are call$ ! prim>y colors ( ! sol> spectrum1 :i* c be produc$ z a b& ( light ( v>iegat$ colors1 arrang$ 9 ! ord] nam$ by pass+ a ray ( ord9>y sunlight ?r\gh a glass prism4 ,! individual rays ( diff]5t color & wave-l5g? t make up a beam ( sunlight1 or :ite light1 !n sep>ate out 9 ! ord] ( ! wave-l5g?s4 ,! r$ rays vibrate ! mo/ sl[ly & h ! longe/ wave-l5g? ( all ! rays ( ! visible spectrum4 ,ab\t f\r hundr$ trillion vibrations ( r$ light rea* ! eye 9 "o second4 ,violet rays1 on ! o!r h&1 vibrate ! mo/ rapidly ( all ! visible rays & h ! %orte/ wave-l5g?4 ,ab\t eight hundr$ trillion vibrations ( violet light rea* ! eye e second4 ,! wave-l5g?s ( ! int]m$iate colors decrease 9 l5g? progressively f ! r$ to ! violet &1 ( c\rse1 ! frequ5cies ( _! vibrations increase 9 ! same ord]4 ,all sunlight is made up ( ^! rays ( diff]5t colors & diff]5t vibration frequ5cies1 & ( o!r rays z well1 to :i* ! human eye is n s5sitive1 & :i*1 !re=e1 d n appe> 9 ! visible spectrum4 ,among ^! invisible rays are ! infra-r$ rays :i* come j bel[ ! r$ ( ! visible spectrum1 & :i* are ( long] wave-l5g? ?an ! r$ rays1 & ! ultra-violet rays1 :i* lie beyond ! violet rays ( ! visible spectrum1 & are ( %ort] wave-l5g? ?an ! violet rays4 ,n[ a ray ( ord9>y sunlight is sep>at$ into ! rays ( v>i\s colors1 :i* =m ! sol> spectrum :5 x passes f a m$ium ( "o d5sity obliquely to a m$ium ( ano!r d5sity1 z :5 x passes f air to glass1 or f air to wat]1 or f out] space into ! e>?'s atmosph]e4 ,"u su* circum/ances its velocity is sl[$ d[n :5 x passes f a r>e to a d5s] m$ium1 & ! waves ( diff]5t wave-l5g?s are b5t f _! =m] c\rse1 or refract$1 by diff]5t am\nts4 ,! r$ rays1 ( longe/ wave-l5g?1 are b5t f _! =m] c\rse ! lea/1 & ! violet rays1 ( %orte/ wave-l5g?1 are b5t ! mo/ ^u pass+ f a r>e to a d5s] m$ium4 ,z a result ! ray ( sunlight is spread out or disp]s$ into its rays ( diff]5t wave-l5g? & color ^u ent]+ a m$ium ( diff]5t d5sity4 ,x is ?is refraction & disp]sion ( sunlight t produces _m color effects 9 ! e>?'s atmosph]e4 ,! atmosph]e is n ( uni=m d5sity ?r\gh\t4 ,at high altitudes x is extremely r>e4 ,t is1 !re is little ( x 9 a giv5 volume4 ,close to ! e>?'s surface1 h[ev]1 x is comp>atively d5se4 ,half ( all ! atmosph]e is )9 ?ree & "o-half miles ( ! surface & half ( ! rema9d] lies )9 ! next ?ree & a half miles4 ,we may consid] x z made up1 on ! :ole1 ( lay]s ( diff]5t d5sities1 /rongly compress$ ne> ! surface4 ,imag9e a ray ( sunlight ent]+ ! e>?'s atmosph]e f )\t4 ,if x comes f a po9t 9 ! z5i? its c\rse is n *ang$ ^u ent]+ ! atmosph]e1 because light pass+ f a c]ta9 m$ium--z space--into a m$ium ( diff]5t d5sity1 is n b5t f its c\rse1 or refract$1 provid$ x ent]s ! new m$ium 9 a direction p]p5dicul> to ! surface4 ,if x ent]s ! atmosph]e 7:i* is ! new m$ium ( great] d5sity7 obliquely1 refraction1 or b5d+ ( ! ray1 takes place1 & z ! ray advances t[>d ! e>?1 ?r\gh lay]s ( increas+ d5sities1 x is b5t f its =m] c\rse m & m4 ,z ! advanc+ rays ( diff]5t colors & wave-l5g?s 9 ! beam ( sunlight are sl[$ d[n 9 ! new m$ium1 ! r$ rays are turn$ f _! c\rse ! lea/ & ! violet rays ! mo/ & ! entire advanc+ wave-front ( ! beam ( sunlight is b5t d[n m & m t[>d ! horizon1 z x proce$s ?r\gh ! atmosph]e4 ,z we on ! e>?'s surface see ! ray n along its b5t c\rse ?r\gh ! atmosph]e1 b 9 ! direction 9 :i* x f9ally ent]s our eyes1 ! effect ( refraction ^u a ray ( light pass+ ?r\gh ! atmosph]e is to displace ! object 9 ! direction ( ! z5i? or increase its di/ance above ! horizon4 ,z a result ( refraction we see ! sun--or moon--above ! we/]n horizon aft] x has really set1 & above ! ea/]n horizon be=e x has really ris54 ,! oval %ape t ! sun1 or moon1 (t5 pres5ts on ris+ or sett+1 is due to ! fact t ! light f ! l[] limb is pass+ ?r\gh d5s] air ?an ! light f ! upp] limb1 & s is refract$ m4 ,z a result ! l[] limb is lift$ proportionately m ?an ! upp] limb4 ,?is di/orts ! =m ( ! sol> or lun> disk1 mak+ x appe> oval in/ead ( circul>4 ,! famili> tw9kl+ or sc9tillation ( />s &1 m r>ely1 ( ! planets1 is a result ( int]f]5ce ( light waves due to irregul> & v>iable refraction 9 air t is n uni=m 9 d5sity1 ow+ to ! pres5ce ( con/antly ris+ & desc5d+ atmosph]ic curr5ts ( diff]5t d5sities4 ,?is also produces ! %imm]+ or un/ead9ess ( /> images 9 ! telescope1 t int]f]es s greatly ) accurate measurem5ts ( angles or obs]vations ( planet>y m>k+s4 ,"o may ask :y x is1 if light f an object1 say a />1 is b5t f its c\rse & sep>at$ into rays ( v>i\s colors ^u ent]+ ! e>?'s atmosph]e1 t we d n see ! object drawn out into a b& ( spectral colors4 ,x is because ! angul> sep>ation ( ! v>i\s colors is s slight "u ord9>y circum/ances t light f "o po9t is bl5d$ ) light f a neighbor+ po9t ( complem5t>y color to produce :ite light aga94 ,"u c]ta9 circum/ances1 h[ev]1 beautiful color effects may be se5 9 ! e>?'s atmosph]e z a result ( ! refraction ( sunlight4 ,! blue color ( ! sky & its brightness is caus$ by ! scatt]+ ( ! rays ( %orte/ wave-l5g?1 ! violet & blue rays1 by ! oxyg5 & nitrog5 9 ! upp] atmosph]e4 ,! molecules ( ^! gases int]f]e ) ! passage ( ^! rays1 p[]fully scatt]+ & disp]s+ !m1 & ?us increas+ ! l5g? ( _! pa? ?r\gh ! air & diffus+ _! color & brightness 9 ! upp] atmosph]e1 :ile p]mitt+ rays ( long] wave-l5g?1 ! r$ & orange1 to pass on practically undi/urb$4 ,:5 an object 9 ! heav5s lies close to ! horizon1 ! rays ( light f x h to travel a long] pa? ?r\gh ! atmosph]e ?an :5 ! object is ov]head1 & t too ?r\gh ! d5se/ "p ( ! atmosph]e1 :i* lies close to ! e>?'s surface1 & 9 :i* are float+ _m du/ p>ticles & impurities f ! e>?'s surface4 ,all ^! p>ticles1 z well z ! increas$ d5sity ( ! atmosph]e1 int]f]e ) ! free passage ( ! rays1 especially ( %ort] wave-l5g?s4 ,! violet & blue rays are sift$ out & scatt]$ 9 _! long j\rney ?r\gh ! l[] /rata ( air1 f> m ?an :5 !y come to u f an object high 9 ! sky4 ,ev5 ! r$ & yell[ rays are m or less scatt]$ & b5t aside--diffract$--by ^! comp>atively l>ge p>ticles ne> ! surface4 ,! r$di% color ( ! sun1 moon & ev5 ( ! />s & planets1 :5 se5 ne> ! horizon1 z well z ! beautiful sunset t9ts1 9 :i* r$s & p9ks & yell[s pr$om9ate1 are due to ! fact t ! rays ( long] wave-l5g? are m successful 9 p5etrat+ ! d5se1 du/-lad5 lay]s ( ! l[] atmosph]e4 ,x is to be free ( ! du/ & impurities z well z ! un/ead9ess ( ! l[] atmosph]e1 t obs]vatories are built at high altitudes :5ev] possible4 ,:5 !re h be5 unusually viol5t volcanic eruptions1 & great quantities ( f9ely divid$ du/ h be5 ?r[n into ! upp] atmosph]e1 ! effect ^u ! blue & violet rays f ! sun is v great4 ,! volcanic du/ p>ticles are s l>ge t in/ead ( scatt]+ ^! rays ( %ort] wave-l5g?1 z d ! oxyg5 & nitrog5 9 our atmosph]e1 !y reflect !m back into space & s decrease ! am\nt ( light & heat receiv$ f ! sun4 ,= ?is reason ! g5]al temp]ature ( ! e>? is l[]$ by viol5t volcanic eruptions4 ,unusually cold p]iods1 t la/$ = mon?s1 foll[$ ! t]rible eruption ( ,krakatoa 9 #ahhc & ( ,katmai 9 #aiab4 ,at times :5 mu* du/ is pres5t 9 ! atmosph]e1 ! sky is a milky :ite color by day z a result ( ! reflection ( sunlight f ! du/ p>ticles4 ,sunrise & sunset colors are !n p>ticul>ly gorge\s1 ) r$s pr$om9at+4 ,at su* times ! blue & violet rays are almo/ completely %ut out1 & ! r$1 orange & yell[ rays are p[]fully diffract$ & scatt]$ by ! du/ p>ticles 9 ! air4 ,! twilight gl[ t is visible = "s "t be=e sunrise or aft] sunset is1 ( c\rse1 entirely an atmosph]ic effect caus$ by ! reflection ( sunlight to our eyes f ! upp] atmosph]e1 ^u :i* ! sun %9es1 :ile x is1 itself1 conceal$ f our view bel[ ! horizon4 ,! atmosph]e ext5ds 9 quantities suffici5t to produce twilight to an elevation ( ab\t sixty miles4 ,:5 all ! rays ( :i* sunlight is compos$ are reflect$ 9 equal proportions we get ! impression ( :ite light4 ,du/ & haze 9 ! air reflect all rays /rongly & give a :iti% color to an o!rwise blue sky4 ,brilliant :ite cl\ds appe> :ite1 because !y are reflect+ all rays equally4 ,cl\ds or portions ( cl\ds appe> black :5 !y are 9 %ade or1 at times1 by contra/ ) portions t are m /rongly illum9at$1 or :5 !y are moi/ure-lad5 & ne> ! po9t ( saturation1 :5 !y are absorb+ m light ?an !y reflect4 ,at sunrise & sunset1 :5 ! light t falls ^u ! cl\ds is ri*e/ 9 r$ & orange & yell[1 cl\ds reflect ^! colors to our eyes1 & we see ! brilliant sunset hues :i* are m int5se ! m ! air is fill$ ) du/ & impurities4 ,! famili> & beautiful ph5om5on ( ! ra9b[ is produc$ by refraction1 reflection & int]f]5ce ( sunlight by drops ( fall+ wat]1 su* z ra9 or spray4 ,z ! ray ( sunlight ent]s ! drop ( wat]1 :i* acts z a t9y glass prism1 x is refract$ or b5t f its c\rse & spread out into its spectral colors4 ,reflection ( ^! rays next takes place 7once or twice1 z ! case may be7 f ! inside ( ! drop & a second refraction ( ! reflect$ ray takes place z x leaves ! drop4 ,! small] ! drops ! m brilliant is ! ra9b[ & ! ri*] 9 color4 ,! mo/ brilliant ra9b[s are produc$ by drops betwe5 #j4b & #j4d millimet]s 9 diamet]4 ,9 addition to ! prim>y b[1 :i* has a r$ out] bord] ) a radius ( #db1 !re is ! second>y b[ ) a radius ( ab\t #ea & ) colors rev]s$1 ! r$ be+ on ! inn] bord]2 ! sup]num]>y b[s :i* are n>r[ b&s ( r$1 or gre5 & r$1 appe> p>allel to ! prim>y & second>y b[s along ! inn] side ( ! prim>y b[ & ! out] side ( ! second>y b[4 ,no ra9b[ ar*es ev] appe> betwe5 ! prim>y & second>y b[s1 & x c be %[n 9 fact1 t ! illum9ation betwe5 ^! two b[s is at a m9imum4 ,! prim>y1 second>y & sup]num]>y b[s all lie opposite ! sun 9 ! direction ( ! obs]v]'s %ad[ & ! obs]v] mu/ /& ) 8 back to ! sun 9 ord] to see !m4 ,! prim>y & second>y ra9b[ ar*es take ! =m ( arcs ( circles t h _! common c5t] on ! l9e connect+ ! sun ) ! obs]v] at a po9t z f> bel[ ! horizon 9 angul> di/ance z ! sun is above ! horizon4 ,x is1 !re=e1 nev] possible to see a ra9b[ ar* ( m ?an a semicircle 9 ext5t unless ! obs]v] is at an elevation above ! surr\nd+ c\ntry1 "u :i* circum/ances x might be possible to see a complete circle =m$ by ! ra9b[4 ,! highe/ & longe/ ar* appe>s :5 ! sun is on ! horizon1 & ! great] ! altitude ( ! sun ! small] & l[] ! visible ar*4 ,z ! angul> radius ( ! prim>y b[ is #db & ( ! second>y b[ #ea & z ! common c5t] ( ! two circles is always z f> bel[ ! horizon z ! sun is above1 x is nev] possible to see ei!r prim>y or second>y ra9b[ :5 ! altitude ( ! sun is ov] #ea1 or ! prim>y b[ :5 ! altitude is ov] #db4 ,= ?is reason ra9b[s are r>ely se5 at or ne> noon 9 mid-latitudes1 s9ce ! sun is usually at an elevation ( m ?an #db at noon1 especially 9 ! summ] season1 :i* is also ! mo/ favorable season = ra9b[s1 ow+ to ! great likelihood ( ra9 & sun%9e occurr+ at ! same "t4 ,! light :i* comes to an obs]v] f ! prim>y b[ is once reflect$ )9 ! drop1 & t :i* comes f ! second>y b[ is twice reflect$ )9 ! drop4 ,! %>p] & bright] light !re=e comes f ! prim>y b[ ( #db radius4 ,! space betwe5 ! two b[s is p>ticul>ly d>k1 because x c be %[n t ! drops !re d n reflect any light at all4 ,! ra9b[ colors are r>ely pure or arrang$ 9 spectral ord]1 ow+ to int]f]5ce ( light waves4 ,x is ! int]f]5ce ( light waves f diff]5t p>ts ( ! same drop t produces ! b&s ( alt]nate maximum & m9imum brightness1 t lie bel[ ! prim>y b[ & beyond ! second>y b[4 ,! r$ or gre5 & r$ b&s ( maximum brightness produc$ ?us by int]f]5ce1 are call$ ! sup]num]>y b[s1 & !y are always f\nd p>allel to ! prim>y & second>y b[ )9 ! =m] & above ! latt]4 ,! di/ance ( ! ra9b[ f ! obs]v] is ! di/ance ( ! drops t =m x4 ,a ra9b[ may be =m$ by cl\ds sev]al miles di/ant or by ! aid ( ! g>d5 hose on our lawn4 ,no two obs]v]s c see exactly ! same ra9b[ because ! ra9b[ ar* encircles ! surface ( a cone ^: v]tex is at ! obs]v]'s eye & no two su* v]tices c exactly co9cide4 ,two obs]v]s see ra9b[s =m$ by diff]5t drops4 ,refraction ( light by ice-cry/als 9 cl\ds produces _m beautiful color effects1 su* z halos ( v>i\s types ar\nd sun or moon1 v]tical light pill>s1 circumz5i?al arcs1 & p>helia--sun-dogs--or p>asel5--moon-dogs--:i* are lum9\s spots at equal altitudes ) sun or moon--"o to ! left ! o!r to ! "r1 at an angul> di/ance ( #bb4 ,! mo/ usual =m ( halo is t ( #bb radius4 ,?is is a lum9\s r+ ( light surr\nd+ sun or moon1 ) ! inn] edge r$ & %>ply def9$ & ! spectral colors proce$+ outw>d 9 ord]2 r$ is frequ5tly ! only color visible1 ! rema9d] ( ! r+ appe>+ :iti%4 ,s9ce ! halo is produc$ by refraction ( light by ice-cry/als1 :i* exi/ 9 cl\ds ( a c]ta9 type ga!r+ at high altitudes1 x is always a v good indicator ( an approa*+ /orm4 ,coronas are lum9\s r+s %[+ ! spectral colors 9 ! rev]se ord]1 t is1 ) ! inn] edge blue in/ead ( r$4 ,!y are usually ( v small radius1 sc>cely two degrees1 closely surr\nd+ sun or moon & are produc$--n by refraction--b by diffraction or a b5d+ aside ( ! rays z !y pass betwe5--)\t ent]+--v small drops ( wat] 9 cl\ds4 ,z 9 ! case ( refraction1 ! r$ rays are turn$ f _! c\rse ! lea/ & ! violet rays ! mo/4 ,_m ( ^! ph5om5a--halos1 lum9\s spots1 v]tical pill>s & arcs ( light may1 at times1 be se5 simultane\sly1 :5 cl\ds ( ice-cry/als are =m+ ar\nd ! sun or moon4 ,!y !n pres5t a v complex & beautiful outl9e ( lum9\s circles1 ar*es & pill>s t h a my/]i\s & almo/ />tl+ appe>ance :5 ! cause is n cle>ly und]/ood4 ,we h f\nd !n t sunlight is made up ( rays ( _m diff]5t wave-l5g?s & colors & t ! atmosph]e acts ^u ^! rays 9 v>i\s ways4 ,x reflects !m or turns !m back on _! c\rse2 x refracts !m z !y pass ?r\gh ! gases ( :i* ! atmosph]e consi/s1 or ?r\gh ! wat]-vapor & ice-cry/als susp5d$ 9 x1 ?us sift+ out & disp]s+ ! rays ( diff]5t colors & wave-l5g?s & produc+ beautiful color effects2 x diffracts !m or b5ds !m aside z !y pass betwe5 ! f9e du/ p>ticles & small drops ( wat] 9 ! air1 aga9 sift+ out ! rays ( diff]5t colors & produc+ color effects simil> to ^? produc$ by refraction2 x also scatt]s & disp]ses1 ?r\gh ! action ( ! molecules ( oxyg5 & nitrog5 9 ! upp] /rata1 ! blue & violet rays ( %ort] wave-l5g? & ?us produces ! blue color & brightness ( ! sky2 x produces beautifully color$ auroral /ream]s & curta9s & rays ( light ?r\gh ! electrical dis*>ges result+ :5 ! r>efi$ gases 9 ! upp] air are bomb>d$ by electrifi$ p>ticles %ot =? f ! sun4 ,x is our atmosph]e1 !n1 t we h to ?ank = all ^! beautiful displays ( color t delight our eyes & give pleasure to our exi/5ce1 z well z = ! v fact ( our exi/5ce ^u a planet t )\t its pres5ce w\ld be an un9habitable wa/e1 cov]$ only ) b>r5 rocks4 ,,xxvi ,,keep+ ,,track ,,( ,,! ,,moon ,( all cele/ial objects ! ne>e/ & mo/ famili> is our satellite1 ! moon4 ,yet ! mi/akes & blund]s t o!rwise intellig5t p]sons frequ5tly make :5 !y ref] to ! v>i\s aspects ( ! moon are q unbelievable4 ,:o has n read 9 classics or 9 popul> fiction ( cresc5t moons rid+ high 9 midnight skies1 ( full moons ris+ above we/]n cliffs or sett+ beyond ea/]n lakes8 ,:o has n se5 ! moon drawn 9 impossible positions ) horns po9t+ t[>d ! horizon1 or a tw9kl+ /> %9+ ?r\gh an app>5tly transp>5t moon8 ,c>eful obs]vation ( ! moon 9 all its v>i\s phases & at diff]5t seasons is ! be/ me?od to be us$ 9 acquir+ a k ( ! elem5t>y facts reg>d+ ! motion ( ! moon ?r\gh ! heav5s f day to day1 b t requires t "o be up (t5 aft] midnight & 9 ! e>ly h\rs prec$+ dawn & s x is t we feel s hazy 9 reg>d to :at happ5s to ! moon aft] x has pass$ ! full4 ,a few fundam5tal rules c be easily acquir$1 h[ev]1 & ^! w enable u to locate ! moon 9 ! "r qu>t] ( ! heav5s at any "t ( ! day or night :5 we "k its phase & ! approximate position ( ! sun at ! same in/ant1 & ?us we may avoid "s ( ! mo/ obvi\s blund]s t are made 9 deal+ ) ! g5]al aspect ( ! moon at any giv5 "t4 ,z c be v]ifi$ by direct obs]vation1 ! moon is always mov+ cont9ually ea/w>d4 ,s9ce x makes a complete revolution ar\nd ! e>? f new moon back to new moon aga9 9 a little less ?an ?irty days1 x passes ov] ab\t twelve degrees a day 7#cfj divid$ by #cj71 on ! av]age1 or "o-half a degree an h\r1 :i* is ab\t ! angul> ext5t ( its own diamet]4 ,!re=e e h\r ! moon moves ea/w>d a di/ance equal to its own diamet]4 ,?is is ( c\rse only approximate z ! moon moves m rapidly 9 "s p>ts ( its orbit ?an 9 o!rs4 ,9 addition to its real ea/w>d motion ! moon %>es ! app>5t daily we/w>d motion ( all cele/ial objects :i* is due to ! daily rotation ( ! e>? on its axis 9 ! opposite direction4 ,t is1 ! moon1 z well z ! sun1 />s & planets1 rises 9 ! ea/ & sets 9 ! we/ daily4 ,on acc\nt ( its cont9u\s ea/w>d motion1 h[ev]1 ! moon rises lat] e night1 on ! av]age ab\t fifty m9utes1 ?\gh ! am\nt ( ?is daily ret>dation ( moon-rise v>ies f less ?an half an h\r to consid]ably ov] an h\r at diff]5t seasons ( ! ye> & 9 diff]5t latitudes4 ,9 ! c\rse ( a mon? !n ! moon has ris5 at all h\rs ( ! day & night & set at all h\rs ( ! day & night4 ,x might seem unnecess>y to emphasize ! fact t ! moon always rises 9 ! ea/ 7 x n t ! a/ronom] occasionally meets ! man :o insi/s t he has at times se5 ! moon rise 9 ! we/4 ,to be sure ! new cresc5t moon fir/ becomes visible above ! we/]n horizon %ortly aft] sunset ?\gh x rises 9 ! ea/ ! morn+ ( ! same day %ortly aft] sunrise4 ,z is also true ( ! sun ! exact po9t on ! horizon :]e ! moon rises or sets v>ies f day to day & f season to season4 ,9 "o mon? ! moon passes ov] v ne>ly ! same pa? ?r\gh ! heav5s t ! sun does 9 "o ye>1 = ! moon's pa? is incl9$ only five degrees to ! ecliptic or app>5t pa? ( ! sun ?r\gh ! heav5s4 ,x c nev] pass m ?an #bh-a_/b 7#bc-a_/b #e7 s\? ( ! cele/ial equator1 nor m ?an #bh-a_/b nor? ( x4 ,x has a slightly great] range 9 altitude ?an ! sun1 !re=e4 ,nor? ( #bh-a_/b nor? latitude x always crosses ! m]idian s\? ( ! z5i? & bel[ #bh-a_/b s\? latitude x crosses ! m]idian nor? ( ! z5i?4 ,9 tropical regions ! moon sometimes passes nor? ( ! z5i?1 sometimes s\?1 or aga9 directly ?r\gh ! z5i?4 ,s9ce ! full moon is always diametrically opposite to ! sun x passes ov] ne>ly ! same "p ( ! heav5s t ! sun did six mon?s be=e4 ,9 w9t] !n :5 ! sun is s\? ( ! equator ! moon rides high at night nor? ( ! equator &1 vice v]sa1 9 summ] :5 ! sun is nor? ( ! equator ! full moon rides l[ s\? ( ! equator4 ,9 w9t] !n we h m h\rs ( moonlight ?an we h 9 summ]4 ,?is may be ( no great advantage 9 mid-latitudes b we may imag9e :at a boon x is to ! inhabitants ( ! ,arctic & ,ant>ctic regions to h ! fri5dly moon above ! horizon dur+ ! long w9t] mon?s :5 ! sun is nev] se5 = days at a "t4 ,at "t ( new moon ! moon lies directly betwe5 u & ! sun1 b ord9>ily passes j to ! nor? or s\? ( ! sun s9ce its orbit is incl9$ five degrees to ! ecliptic or plane ( ! e>?'s orbit4 ,if ! moon's pa? lay exactly 9 ! ecliptic we w\ld h an eclipse ( ! sun e mon? at new moon & an eclipse ( ! moon two weeks lat] at full moon4 ,n[ ! moon crosses ! ecliptic twice a mon?1 ! po9ts ( cross+ be+ call$ ! nodes ( its orbit1 b only twice a ye> is ! moon ne>ly en\gh 9 l9e ) ! sun at ! "t x crosses to cause eclipses4 ,e ye>1 !n1 !re are two eclipse seasons1 sep>at$ by int]vals ( six mon?s1 :5 ! moon is 9 l9e ) ! sun at or close to ! po9t :]e x crosses ! ecliptic2 !n & only !n c sol> & lun> eclipses occur4 ,! sol> eclipses1 ( c\rse1 w occur :5 ! moon is new1 t is1 :5 ! moon passes directly betwe5 ! e>? & ! sun & ?r[s its %ad[ ov] ! e>?2 & ! lun> eclipses two weeks lat] :5 ! e>? passes betwe5 ! sun & moon & ?r[s its %ad[ ov] ! face ( ! moon4 ,probably !re is no a/ronomical subject t has be5 m g5]ally misund]/ood ?an t ( sol> & lun> eclipses4 ,x is well to rememb] t sol> eclipses c only occur at "t ( new moon & lun> eclipses only at ! "t ( full moon2 & at ! "t ( eclipses1 :e!r lun> or sol>1 ! moon is at or ne> its nodes1 ! po9ts :]e its orbit crosses ! ecliptic4 ,!re are always at lea/ two sol> eclipses e ye> & !re may be z _m z five4 ,!re are ye>s :5 !re are no lun> eclipses1 ?\gh ord9>ily bo? sol> & lun> eclipses occur e ye>1 "s p>tial o!rs total4 ,! moon %9es only by reflect$ sunlight4 ,x is ( itself a solid1 d>k body ) its day surface int5sely hot & its night surface int5sely cold1 a _w ( extreme temp]atures4 ,at new moon all ( ! night side ( ! moon is turn$ t[>d u1 at full moon all ( ! day side4 ,at o!r phases we see "p ( ! day side & "p ( ! night side & ! illum9at$ side ( ! moon is always ! side t is t[>ds ! sun4 ,failure to obs]ve ?is simple rule leads to _m griev\s blund]s 9 depict+ ! moon4 ,at ! "t ( new moon ! moon1 mov+ cont9ually ea/w>d1 passes nor? or s\? ( ! sun f we/ to ea/ except :5 x passes directly 9 front ( ! sun1 caus+ eclipses4 ,a day or s lat] ! wax+ cresc5t moon or ! new moon1 z x is popul>ly call$1 becomes visible l[ 9 ! we/ imm$iately aft] sunset4 ,! moon is n[ ea/ ( ! sun & w rema9 ea/ ( ! sun until ! "t ( full moon4 ,dur+ ! p]iod f new moon to full moon x w1 !re=e1 rise aft] ! sun & set aft] ! sun4 ,! wax+ cresc5t moon w n be visible 9 ! morn+ h\rs because1 inasmu* z x rises aft] ! sun1 x is lo/ to view 9 ! sun's brilliant rays4 ,nev]!less1 x foll[s ! sun across ! sky & becomes visible 9 ! we/ z soon z ! sun has disappe>$ bel[ ! we/]n horizon4 ,! ?9 illum9at$ cresc5t has its horns or cusps turn$ away f ! po9t :]e ! sun has set4 ,! horns ( ! cresc5t c nev] po9t t[>d ! horizon s9ce ! illum9at$ side ( ! moon is always turn$ t[>d ! sun :e!r ! sun is above or bel[ our horizon4 ,z h\r by h\r & day by day ! moon draws f>!r ea/w>d & increases its angul> di/ance f ! sun1 m & m ( ! illum9at$ side becomes visible2 ! cresc5t increases 9 wid? & area & ! moon appe>s high] 9 ! we/]n sky ea* night at sunset4 ,usually ab\t sev5 & a fraction days aft] ! date ( new moon ! moon completes ! fir/ qu>t] ( its revolution ar\nd ! e>?4 ,! p]iod f "o phase to ! next is v>iable & irregul>1 be+ sometimes less ?an sev5 days & at o!r times m ?an eight days1 s9ce ! moon does n move at a uni=m rate 9 diff]5t p>ts ( its orbit4 ,:5 ! moon has complet$ ! fir/ qu>t] ( a revolution x is n9ety degrees ea/ ( ! sun & pres5ts ! phase kn[n z half-moon s9ce half ( ! surface t is turn$ t[>d ! e>? is illum9at$ & half is 9 d>kness4 ,x is said to be at ! fir/ qu>t]4 ,! illum9at$ half is ( c\rse ! we/]n half because ! sun is to ! we/ ( ! moon4 ,! half moon is ne> ! m]idian at sunset & sets ne> midnight4 ,up to ! fir/ qu>t]1 !n1 ! moon is a cresc5t 9 ! we/]n sky dur+ ! fir/ "p ( ! night & %\ld nev] be repres5t$ z ea/ ( ! m]idian or ne> ! m]idian at midnight4 ,aft] ! moon has pass$ ! fir/ qu>t] & be=e x is full m ?an half ( ! side turn$ t[>d ! e>? is illum9at$ & x is 9 ! gibb\s phase4 ,x is /ill ! we/]n limb t is fully illum9at$4 ,! moon is n[ ea/ ( ! m]idian at sunset & x crosses ! m]idian be=e midnight & sets be=e sunrise4 ,all :o are abroad dur+ ! fir/ half ( ! night f9d ?is phase ( ! moon m favorable to !m ?an ! gibb\s phase foll[+ full moon4 ,! moon n[ be+ above ! horizon at sunset is visible cont9u\sly f sunset to midnight b sets "s "t dur+ ! second half ( ! night1 :ile ! full moon %9es ?r\gh\t ! night1 ris+ 9 ! ea/ at sunset & sett+ 9 ! we/ at sunrise4 ,:5 ! moon is full x is #ahj ea/1 or we/1 ( ! sun & s bo? its ea/]n & we/]n limbs are p]fectly illum9at$4 ,aft] ! full ! moon goes ?r\gh its phases 9 rev]se ord]1 be+ fir/ gibb\s1 !n a half-moon once m1 & la/ly a wan+ cresc5t4 ,x is n[ we/ in/ead ( ea/ ( ! sun & s x is ! ea/]n limb t is fully illum9at$ by ! sun4 ,be+ we/ ( ! sun x w n[ rise be=e ! sun & set be=e ! sun1 ! int]val decreas+ ea* day z ! moon draws 9 t[>d ! sun once m4 ,! gibb\s phase prec$+ full moon is favorable to all abroad be=e midnight b ! gibb\s phase foll[+ full moon is m favorable to ^? :o are abroad aft] midnight1 = f full moon to la/ qu>t] ! moon is bel[ ! horizon at sunset1 & ( c\rse1 is ris+ lat] & lat] ea* night1 :ile at sunrise x is /ill above ! horizon1 appe>+ ea* day high] & high] above ! we/]n horizon at sunrise z x approa*es ! ?ird or la/ qu>t]4 ,:5 x has rea*$ ?is po9t x is once m a half-moon1 ?\gh n[ x is ! ea/]n half in/ead ( ! we/]n half ( ! disk t is fully illum9at$4 ,! moon is #ij we/ ( ! sun at ?ird qu>t] & f ?is phase to ! phase ( new moon x is a cresc5t once m1 b n[ a wan+ in/ead ( a wax+ cresc5t4 ,x appe>s ea/ ( ! m]idian be=e sunrise & z ! cresc5t gr[s ?9n] x draws ne>] & ne>] to ! ea/]n horizon & ! ris+ sun4 ,z ) ! wax+ cresc5t moon ! horns are turn$ away f ! horizon4 ,! wan+ cresc5t moon is always to be look$ = ea/ ( ! m]idian & to be associat$ ) ! ris+ sun1 :ile ! wax+ cresc5t moon is to be look$ = we/ ( ! m]idian & associat$ ) ! sett+ sun4 ,nei!r ! wax+ nor ! wan+ cresc5t moon w be visible dur+ ! midnight h\rs4 ,z ! wan+ cresc5t moon gr[s ?9n] & draws 9 clos] to ! sun ea* successive night1 its "t ( ris+ prec$es t ( ! sun by an ev]-decreas+ int]val until f9ally ! cresc5t disappe>s f view 9 ! ea/]n sky2 ! next day we see no cresc5t ei!r 9 ! ea/]n or we/]n skies--! moon is once m 9 conjunction ) ! sun & new4 ,"o revolution ( ! moon ab\t ! e>? ) respect to ! sun has be5 complet$ & a day or s lat] we may look = a new cresc5t moon 9 ! we/]n sky aft] sunset4 ,,xxvii ,,! ,,motions ,,( ,,! ,,heav5ly ,,bodies ,ab\t ?ree hundr$ & tw5ty ye>s ago ,giordano ,bruno 0 burn$ at ! /ake = 8 audacity 9 believ+ 9 ! exi/5ce ( o!r worlds4 ,a few decades lat] ! fam\s a/ronom] ,galileo 0 =c$ to publicly recant 8 belief t ! e>? mov$4 ,yet ! tru? c\ld n long be suppress$ by su* means1 & s9ce ^? d>k days man's advance 9 k has be5 s rapid t x seems to u today 9 ?is wond]ful age ( sci5tific discov]y almo/ inconceivable t man ev] believ$ t ! e>?1 a t9y planet ( a va/ sol> sy/em1 0 ! hub ( ! univ]se1 ! fix$ & immovable c5t] ab\t :i* revolv$ all ! heav5ly bodies4 ,v reluctantly1 h[ev]1 & ) bitt] feel+1 b 9 ! light ( ov]:elm+ evid5ce man f9ally gave up 8 long-*]i%$ idea ( t]re/rial importance1 & :5 f9ally =c$ to move 8 fix$ c5t] ( ! univ]se1 he mov$ x only s f> z ! comp>atively ne>by sun4 ,?is c5t] he !n reg>d$ z fix$ 9 space & also held to 8 belief t ! />s1 set 9 an imag9>y cele/ial sph]e1 7 immovable 9 space z well1 & all at ! same di/ance f ! sun4 ,s1 sc>cely two hundr$ ye>s ago we f9d t ! a/ronom] ,bradley 0 endeavor+ to measure ?is common di/ance ( ! fix$ />s4 ,?\gh he fail$ 9 ?is attempt he made ! important discov]y t ! obs]v$ positions ( ! />s are n _! true positions1 ow+ to ! fact t ! velocity ( light is n inf9ite b takes a def9ite f9ite int]val ( "t to travel a giv5 di/ance4 ,z a result ! />s always appe> displac$ 9 ! direction ( ! e>?'s motion ar\nd ! sun1 ! am\nt ( ! displacem5t dep5d+ ^u ! velocity ( ! e>? 9 its orbit & ! velocity ( light4 ,?is ab]ration ( light1 z x is call$1 furni%$ additional pro( t ! e>? revolves ab\t ! sun & 0 "o m nail driv5 into ! c(f9 ( ! old ,ptolemaic !ory t ! e>? 0 ! c5t] ( ! univ]se4 ,bradley also discov]$ t ! positions ( ! />s 7 affect$ by ! wabbl+ ( ! e>?'s axis1 call$ its nutation4 ,al?\gh 9 ! days ( ,bradley nei!r ! me?ods ( obs]vation nor ! in/rum5ts 7 suffici5tly accurate to %[ ! m9ute %ifts 9 ! positions ( ! />s t reveal ! individual motions ( ! />s & ! di/ances ( ^? ne>e/ to u1 yet ! discov]y ( ! two l>ge displacem5ts 9 ! positions ( all ! />s1 due to ! ab]ration ( light & ! nodd+ ( ! e>?'s axis 7 ( ! greate/ value1 = !y 7 a necess>y /ep 9 ! direction ( ! precise measurem5ts ( mod]n times4 ,x is only ?r\gh measurem5ts ( ! greate/ ref9em5t & accuracy t x is possible to detect ! motions & di/ances ( ! />s & to discov] ! wond]ful tru?s ab\t ! nature & /ructure ( ! univ]se t !y are reveal+ to u today4 ,aft] unsuccessful attempts ext5d+ ov] sev]al c5turies ! di/ance ( "o ( ! ne>e/ />s1 ! fa9t #fa ,cygni1 z x is catalogu$1 0 f9ally det]m9$ by ! a/ronom] ,bessel 9 ! ye> #ahch4 ,?is /> is ab\t t5 light-ye>s di/ant f ! e>?1 :i* places x ab\t six hundr$ & ?irty ?\s& times f>!r away f u ?an ! sun2 t is1 we w\ld h to travel six hundr$ & ?irty ?\s& times ! di/ance f ! e>? to ! sun to rea* ?is v close /ell> neighbor1 #fa ,cygni4 ,! ne>e/ ( all ! />s1 ,alpha ,c5tauri1 is ov] two hundr$ & sev5ty ?\s& times ! di/ance f ! e>? to ! sun4 ,x is1 !re=e1 little wond] t ! e>ly a/ronom]s believ$ t ! />s 7 fix$ 9 space s9ce ev5 ! ne>e/ is s f> away t1 view$ f opposite po9ts 9 ! e>?'s orbit1 its app>5t *ange 9 position due to our actual *ange 9 position ( #ahf1jjj1jjj miles1 am\nts to only "o & a half seconds ( arc4 ,two />s sep>at$ by "o hundr$ & sixty times ?is angul> di/ance might possibly be glimps$ z two di/9ct />s by a p]son ) good eyesight1 ?\gh to mo/ ( u !y w\ld appe> z "o />4 ,^u ! measurem5t ( su* m9ute angles dep5d$ a k ( ! di/ances ( ! ne>e/ />s4 ,x is to ,sir ,william ,h]s*el t we owe ! discov]y1 m ?an a hundr$ ye>s ago1 ( ! motion ( ! sun ?r\gh ! univ]se4 ,f ! consid]ation ( a long s]ies ( obs]vations ( ! positions ( ! />s ?is fam\s a/ronom] discov]$ t ! />s 9 ! direction ( ! con/ellation ,h]cules 7 sep>at$ by mu* great] angul> di/ances ?an ! />s diametrically opposite 9 ! heav5s4 ,9 o!r words1 ! />s 7 spread+ ap>t 9 "o portion ( ! heav5s & cr[d+ toge!r 9 ! opposite direction & he rightly int]pret$ ?is to mean t ! sun 0 mov+ 9 ! direction ( ! con/ellation ( ,h]cules4 ,x 0 n until ! spectroscope 0 appli$ to ! /udy ( ! heav5s 9 ! latt] "p ( ! n9ete5? c5tury t ! am\nt ( ?is motion ( ! sun 0 f\nd to be ab\t twelve & a half miles p] second1 or f\r times ! di/ance f ! e>? to ! sun 9 a ye>4 ,x is to ,sir ,william ,h]s*el t we owe also ! discov]y ( b9>y sy/ems ( />s 9 :i* two />s sw+ ar\nd a po9t betwe5 !m call$ _! c5t] ( gravity4 ,illu/ration3 ,,spiral ,,nebula ,,9 ,,canes ,,v5atici ,tak5 ) #fj-;in* ,reflector ( ! ,mt4 ,wilson ,obs]vatory ,our fir/ conception ( ! imm5sity & gr&eur ( ! univ]se dates f ! "t ( ! old] ,h]s*el only a c5tury or s ago4 ,! my/]i\s nebul & /> clu/]s 7 !n discov]$1 ! wond]s ( ! ,milky ,way 7 explor$1 & a new planet & satellites 9 our own sol> sy/em 7 discov]$4 ,x 0 f\nd t ! sun & ! />s z well z ! planets 7 9 motion4 ,nei!r sun nor e>? c\ld be reg>d$ any long] z a fix$ po9t 9 ! univ]se4 ,) ! application ( ! spectroscope to ! /udy ( ! heav5s t[>d ! end ( ! n9ete5? c5tury ! key to a treasure-h\se ( k 0 plac$ 9 ! h&s ( ! a/ronom]s ( mod]n times & z a result we are n[ le>n+ m1 9 a few decades1 ab\t ! wond]s & my/]ies ( ! heav5s ?an 0 grant$ to man to le>n 9 c5turies ( e>li] endeavor4 ,yet x is ! feel+ ( ! a/ronom] ( today t he is only /&+ on ! ?re%old ( k & t ! greate/ ( all discov]ies1 t ( ! nature ( matt] & ( "t & space is yet to be made4 ,x is ! spectroscope t tells u s _m wond]ful facts ab\t ! motions ( ! />s1 nebul & /> clu/]s4 ,x tells u also practically all we "k ab\t ! physical condition ( our own sun & ( ! o!r suns ( ! univ]se1 _! temp]ature & age1 & ! peculi>ities ( _! atmosph]es4 ,"s ( ! mo/ important a/ronomical discov]ies t h be5 made 9 ! pa/ few ye>s h to d ) ! di/ribution & velocities ( ! heav5ly bodies z reveal$ by ! spectroscope4 ,x has be5 f\nd1 ) ! aid ( ! spectroscope1 t ! mo/ sl[ly mov+ ( all />s are ! extremely hot blui% ,orion />s ) an av]age velocity ( eight miles p] second1 :ile ! mo/ rapidly mov+ />s are ! deep-r$ />s ) an av]age velocity ( tw5ty-"o miles p] second1 & !re is 9 all cases a relation%ip exi/+ betwe5 ! color1 or spectrum1 ( a /> & its velocity4 ,! reason = ?is connection betwe5 ! two /ill rema9s undiscov]$4 ,! spectroscope has also told u "s a/oni%+ facts 9 rec5t ye>s ab\t ! velocities ( ! spiral nebul4 ,x is n[ kn[n t ^! my/]i\s objects are mov+ ) ! trem5d\s av]age velocity ( f\r hundr$ & eighty miles p] second1 :i* exce$s ! av]age velocity ( ! />s fully tw5ty-five fold4 ,!y possess1 moreov]1 int]nal motions ( rotation t are almo/ z high z _! velocities ?r\gh space4 ,x is n[ g5]ally believ$ t spiral nebul are f> di/ant objects ( enorm\s size & mass1 ext]ior to our own sy/em ( />s & simil> to x 9 =m4 ,9 place ( ! univ]se ( ! fix$ />s & ! immovable sun or e>? ( a few c5turies ago we f9d t mod]n a/ronomical discov]y is sub/itut+ a univ]se ( inconceivable gr&eur & imm5sity 9 a /ate ( ceaseless flux & *ange4 ,our e>?--an atom sp9n+ ab\t on its axis & revolv+ rapidly ar\nd a huge sun t is equal 9 volume to m ?an a million e>?s--is c>ri$ onw>d ) ?is sun ?r\gh a va/ univ]se ( suns4 ,only an av]age-siz$ /> among sev]al hundr$ million o!r />s is ?is huge sun ( ours1 mov+ ) its planet family ?r\gh ! regions ( ! ,milky ,way1 :]e are to be f\nd n only mov+ clu/]s & gr\ps ( />s1 spe$+ along _! way 9 ob$i5ce to ! laws ( motion ( ! sy/em to :i* !y belong1 b also /rangely =m$ nebul cov]+ va/ /ret*es ( space1 :irl+ & see?+ int]nally & %9+ ) my/]i\s light1 & /ill o!r /ret*es ( d>k obscur+ matt] %utt+ (f ! rays ( suns beyond4 ,! ext5t & =m ( ?is enorm\s sy/em ( />s & nebul & ! laws t gov]n ! motions ( its individual memb]s are among ! problems t ! a/ronom]s ( today are attempt+ to solve4 ,on bo? sides ( ^! regions ( ! ,milky ,way1 :]e9 lies our own sol> sy/em1 lie o!r va/ sy/ems1 su* z ! globul> /> clu/]s1 compos$ ( ?\s&s1 possibly hundr$s ( ?\s&s1 ( suns2 ! ,magellanic cl\ds1 :i* resemble deta*$ portions ( ! ,milky ,way1 &1 probably1 ! mu* discuss$ spiral nebul1 possible isl& univ]ses simil> to our own4 ,we h come f> 9 ! pa/ ?ree hundr$ ye>s f ! conception ( an immovable e>? at ! c5t] ( ! univ]se to ?is awe-inspir+ conception ( ! univ]se t we h today1 :i* is bas$ ^u mod]n a/ronomical discov]ies4 ,:atev] may be discov]$ 9 ! future 9 reg>d to ! =m & ext5t ( ! univ]se ! idea ( a fix$ & immovable c5t] ei!r )9 ! sol> sy/em or among ! />s beyond has gone f ! m9ds ( m5 at la/4 ,illu/ration3 ,,spiral ,,nebula ,,9 ,,&rom$a ,,view$ ,,edgewise ,tak5 ) #fj-;in* ,reflector ( ! ,mt4 ,wilson ,obs]vatory ,n m ?an a g5]ation ago a survival ( ! old idea ( a fix$ c5t] 0 se5 9 ! belief t ,alcyone1 9 ! ,pleiades 0 a c5tral sun ab\t :i* all ! />s revolv$4 ,x is n[ well kn[n t ! ,pleiades =m a mov+ /> clu/]4 ,alcyone is !re=e drift+ sl[ly onw>d ?r\gh ! univ]se & ! idea ( a fix$ & immovable c5t] to :i* man may an*or 8 ideas is drift+ away also4 ,!re are1 x is true1 local c5t]s ( sy/ems1 su*1 = in/ance1 z ! sun occupies 9 ! sol> sy/em or "s gr\p ( />s may occupy 9 ! /ell> sy/em to :i* our sun belongs1 yet z a :ole ^! sy/ems move on & _! c5t]s ) !m4 ,!re is no evid5ce today t any absolutely immovable po9t exi/s 9 ! heav5s4 ,no cele/ial object has be5 f\nd to be )\t ! attribute ( motion1 n only motion onw>d ?r\gh ! univ]se1 b also rotational motion ab\t an axis ( ! body4 ,! planets rotate on _! axes z well z revolve ab\t ! sun1 & ! sun also turns on its axis z x moves onw>d ?r\gh space4 ,?is rotational motion is also f\nd 9 ! nebul & /> clu/]s z well z 9 ! />s & planets4 ,no object 9 ! heav5s is kn[n to be )\t x4 ,ev5 ! sl[ly drift+ ,orion nebula possesses a rapid int]nal velocity ( rotation4 ,!re is no su* ?+ z a body absolutely at re/ 9 ! univ]se4 ,,table ,%[+ ! numb] & relative size1 velocity & di/ribution ( ! v>i\s types ( cele/ial objects4 ,velocities ,object ,numb] ,diamet] miles ,di/ribution p] sec4 ---------------------------------------- ---------------------------------------- --------- #a4 ,sol> ,sy/em a4 ,planets ,eight #c1jjj to #hh1jjj mi4 #c to #ce ,revolv+ 9 ne>ly miles circul> orbits p] sec4 ab\t ! sun4 b4 ,sun #hfd1jjj mi4 #ab-a_/b mi4 ,travell+ ?r\gh galactic sy/ems ( #b4 ,/>s />s 7,milky ,way74 a4 ,helium #h mi4 7blui%7 b4 ,hydrog5 ,approx4 ,dw>fs #ad mi4 ,all types ( />s are 7:ite7 #b1jjj1jjj1jjj 7,two #ejj1jjj to m or less cr[d$ c4 ,sol> ?\s& million7 #a1jjj1jjj mi4 #ah-ai mi4 t[>d plane ( ,milky 7yell[7 ,way 9 l5s %ap$ d4 ,type ,m ,includ+ all types ,giants #ba mi4 =mation4 7,milky 7r$7 #aj1jjj1jjj to ,way possibly a spiral #djj1jjj1jjj mi4 nebula47 #c4 ,nebul a4 ,diffuse or ,num]\s ,v ext5sive1 _m ,v l[ ,9 or close to ,milky ,gase\s light ye>s4 ,way4 b4 ,spiral ,approx4 #gjj1jjj ,size & di/ance ,av]age ,f> ext]nal to ,milky 7sev5 hundr$ d\btful b #dhj mi4 ,way & num]\s ?\s&7 v great4 ne> its poles4 c4 ,planet>y ,"o hundr$ & ,sev]al times t ,av]age ,9 or close to ,milky fifty 7#aej7 ( ! sol> sy/em #dh mi4 ,way4 on ! av]age4 #d4 ,globul> ,/>,ab\t "o hundr$ #bb1jjj-bbj1jjj ,v high ,ext]nal to ,milky ,way ,clu/]s kn[n light-ye>s4 & sph]ically di/ribut$ ab\t x4 #e4 ,magellanic ,two 7,great] & ,?\s&s ( ,v high ,f> beyond ,milky ,way4 ,cl\ds ,less]7 light-ye>s4 ,,xxviii ,,! ,,evolution ,,( ,,! ,,/>s--,,f ,,r$ ,,giants ,,to ,,r$ ,,dw>fs ,! mo/ casual ( />-gaz]s is aw>e t ! />s diff] "o f ano!r 9 color & 9 brightness4 ,!re are r$ />s1 yell[ />s1 :ite />s & blui%-:ite />s4 ,!re are ! brilliant />s ( fir/ magnitude su* z ,vega1 ,capella & ,ant>es1 & !re are1 on ! o!r h&1 />s s fa9t t !y c b>ely be glimps$ ) ! mo/ p[]ful telescopes4 ,9 g5]al ! mo/ brilliant />s are ! ne>e/ & ! fa9te/ />s are ! mo/ di/ant1 b !re are _m exceptions to ! rule1 s9ce !re are />s t appe> fa9t ev5 :5 comp>atively ne> because !y are small & %9e ) a feeble light4 ,su* a /> is ! fa9t1 six?-magnitude />1 #fa ,cygni1 "o ( ! ne>e/ ( all ! />s4 ,aga91 !re are />s 9 f>-di/ant clu/]s visible only 9 p[]ful telescopes t 9 actual brightness exce$ our own sun sev]al ?\s& times & 9 volume sev]al million times4 ,a /> ! size ( ! sun w\ld be invisible 9 ! mo/ p[]ful telescope 9 exi/5ce if x 7 at ! di/ance ( _m />s 9 ! ,milky ,way or globul> /> clu/]s4 ,/>s diff] 9 color because !y diff] 9 temp]ature4 ,we are all aw>e ( ! fact t a piece ( iron :5 heat$ fir/ gl[s a deep r$1 !n appe>s yell[i% 9 color & f9ally atta9s to :ite heat4 ,x is ! same among ! />s4 ,! r$ />s are ! coole/ ( all ! />s & ! blui%-:ite />s are ! hotte/ ( all ! />s1 :ile int]m$iate betwe5 !m 9 temp]ature come ! yell[ & ! :ite />s4 ,n[ z ! biologi/ & ! geologi/ see 9 ?is _w ( ours signs ( evolution1 or gradual developm5t & *ange f ! simple to ! m complex =ms1 & ( gr[? & decay1 s ! a/ronom] sees among ! />s signs ( a cont9u\s1 progressive developm5t f "o type ( /> to ano!r4 ,/>s %>e 9 ! g5]al evolution t is ! law ( ! univ]se1 & are born1 rea* ! height ( _! developm5t1 decl9e to old age & die4 ,)9 ! pa/ few ye>s important a/ronomical discov]ies h be5 made t %[ ! true ord] ( ?is evolution ( ! />s4 ,x 0 believ$ n s long ago t ! blue-:ite helium />s--! type ,b />s ! a/ronom]s call$ !m1 or ! ,orion />s1 s9ce !re are s _m />s ( ?is type 9 ! con/ellation ( ,orion--7 n only ! hotte/ b also ! y\nge/ ( ! />s & t !y repres5t$ ! fir/ /age 9 ! developm5t ( a /> f a primitive gase\s nebula su* z ! ,great ,orion ,nebula4 ,x is n[ kn[n t ^! brilliant1 hot helium />s repres5t ! peak ( developm5t ( ! mo/ massive ( all ! />s & n ! fir/ /ages 9 ! developm5t4 ,a />1 x is n[ kn[n1 comes into exi/5ce z a giant1 r$di% /> ( enorm\s size & ( a d5sity only ab\t "o-?\s&? t ( ! e>?'s atmosph]e at sea-level4 ,x is inconceivably t5u\s or r>e1 & its temp]ature is comp>atively l[1 ab\t #c1jjj ,c5tigrade or less4 ,x is n evolv$ f ! lum9\s1 gase\s nebul because r$ />s are nev] f\nd associat$ ) ! gase\s nebul1 z are ! blue-:ite />s4 ,! orig9 ( ^! r$ giant />s is unc]ta91 b x is possible t !y may be gradually evolv$ 9 "s mann] f ! d>k cl\ds ( obscur+ matt] or d>k nebul t exi/s s abundantly 9 ! heav5s4 ,9 ! next /age ( its developm5t ! deep-r$ giant /> increases 9 temp]ature z x contracts "u ! action ( gravitation & its color gradually *anges f r$ to yell[4 ,its d5sity increases slightly & its volume decreases4 ,x is n[ a yell[ giant />4 ,z ! evolution progresses 9 ! c\rse ( ages ! /> cont9ues to contract1 its temp]ature increases greatly z does also its d5sity & x cont9ues to decrease 9 volume4 ,x is n[ a brilliant :ite />1 a hydrog5 />1 s call$ because its spectrum is *iefly *>act]iz$ by ! l9es ( hydrog54 ,z ! /> contracts "u ! gravitation ( its p>ts & increases 9 temp]ature & d5sity !re comes m & m into play an important factor t has a great effect ^u its future developm5t4 ,?is is light-pressure or radiation pressure :i* acts 9 opposition to gravity & ex]ts a /rong outw>d pressure ^u matt] )9 ! dep?s ( ! />1 t5d+ to pu% x outw>d f ! c5t] :]e ! temp]ature is greate/ & ! light is mo/ int5se4 ,x is a mo/ int]e/+ fact t if ! mass ( a />1 t is ! quantity ( matt] t x conta9s1 exce$s a c]ta9 value ! pressure ( light or radiation )9 x ov]balances ! gravitational attraction t draws matt] t[>ds its c5t] & ! /> dis9tegrates or ceases to exi/ z a />4 ,?is acc\nts = ! fact t ! />s diff] v little among !mselves 9 ! quantity ( matt] t !y conta91 t is1 9 _! masses1 ?\gh !y may diff] enorm\sly 9 size4 ,/>s t exce$ a c]ta9 mass w become un/able & ?is may acc\nt = ! association ( lum9\s nebul ) ! hotte/ ( all />s1 ! nebul possibly be+ puff$ (f f ! surfaces ( ^! />s "u ! action ( radiation pressure4 ,aft] a /> has rea*$ ! height ( its developm5t z a blui%-:ite helium /> ) a temp]ature ( some?+ l #aj1jjj ,c5tigrade & a d5sity ab\t "o-t5? t ( ! sun1 x beg9s to lose heat & to cool gradually ?\gh x cont9ues to contract & increase 9 d5sity4 ,x is n[ on ! desc5d+ scale ( evolution & is to be c\nt$ among ! dw>fs in/ead ( ! giants4 ,a brilliant blue-:ite helium or ,orion /> is ab\t "o hundr$ times m lum9\s ?an ! sun1 & its diamet] is ab\t t5 times t ( ! sun4 ,our own sun1 we f9d1 is on ! desc5d+ scale ( /ell> evolution4 ,x is a yell[ dw>f /> ( temp]ature ab\t #f1jjj ,c5tigrade & d5sity "o & "o-f\r? t ( wat]1 :i* is probably ab\t z great a d5sity z is atta9$ by any /> s9ce ev5 ! non-lum9\s planets ,jupit] & ,saturn h l[] d5sities ?an ! sun4 ,! la/ /age 9 ! developm5t ( a /> is repres5t$ by ! dw>f r$ /> ( high d5sity & l[ temp]ature4 ,! diamet] ( ! dw>f r$ /> probably av]ages ab\t five hundr$ ?\s& miles & its temp]ature is #c1jjj ,c5tigrade or less4 ,aft] ?is we h ! ext9ct />s1 simil> possibly to our planet ,jupit]1 ?\gh consid]ably l>g]1 ) a d5se gase\s atmosph]e & a c]ta9 degree ( int]nal heat4 ,we h trac$ ! evolution ( a /> f a r$ giant to a r$ dw>f ?r\gh ! int]m$iate /ages f yell[ giant to a giant helium /> ) increas+ temp]ature & !nce to yell[ dw>f & r$ dw>f z ! temp]ature decreases4 ,only ! mo/ massive />s pass ?r\gh ?is entire *a9 ( evolution4 ,/>s ( small mass nev] atta9 to ! spl5dor ( brilliant blue-:ite helium />s1 b beg9 to decrease 9 temp]ature & brightness be=e ?is /age is rea*$4 ,! "t requir$ = ! evolution ( a /> f r$ giant to r$ dw>f is n kn[n1 b x mu/ be v great4 ,! age ( ! e>?1 :i* is probably equal to t ( ! sol> sy/em1 is e/imat$ z some?+ l "o ?\s& million ye>s4 ,x is probable t ! av]age life ( a /> f> exce$s ?is limit4 ,,xxix ,,d\ble ,,& ,,multiple ,,/>s ,! plan ( ! sol> sy/em :i* consi/s ( a c5tral sun encircl$ by satellites t are f> inf]ior to _! lum9>y 9 size1 & t move ab\t x 9 orbits t are almo/ p]fect circles1 is n ! only1 nor possibly1 ev5 ! mo/ g5]al "o 9 ! univ]se4 ,sweep+ ! heav5s ) p[]ful telescopes "o is a/oni%$ to f9d t myriads ( />s c be sep>at$ into two or m physically connect$ suns t are (t51 moreov]1 ( exquisitely t9t$ & contra/+ %ades4 ,gre5 & r$1 orange & blue1 :ite & gold5 or :ite & blue pairs exi/ 9 pr(usion1 & /range to say !re are well-au!nticat$ in/ances ( color *anges tak+ place tempor>ily )9 ! same sy/em4 ,a pair ( :ite />s has be5 kn[n to *ange )9 a few decades1 fir/ to gold5 yell[ & blui% gre5 & !n to orange & gre54 ,! fam\s pair catalogu$ z #ie ,h]culis 0 not$ to *ange f gre5 & r$ to a pali% yell[ & back to ! orig9al /rongly contra/+ hues )9 ! c\rse ( a s+le ye>1 :ile at ano!r "t !y appe>$ to be a p]fectly :ite pair4 ,at ! pres5t "t bo? ( ^! />s are decid$ly yell[i% 9 color4 ,su* *anges 9 hue are probably due to tempor>y di/urbances 9 ! atmosph]es ( ! />s1 possibly ( an electrical nature or to sudd5 or unusual outbur/s ( activity1 conc]n+ ! orig9 ( :i* we are z mu* 9 d\bt z we are ( ! cause ( ! sun-spot cycle & p]iodic v>iation 9 ! int5sity ( radiation ( our own sun4 ,tempor>y *anges 9 ! color ( ! compon5ts ( d\ble /> sy/ems sometimes take place :5 ! two />s approa* _! p]ia/ron or po9t ( ne>e/ approa*4 ,ow+ to ! great ecc5tricity ( ! orbits ( d\ble />s1 su* />s are any:]e f twice to n9ete5 times z ne> to ea* o!r at p]ia/ron z !y are at apa/ron1 or po9t ( greate/ dep>ture4 ,su* great *anges 9 ! relative di/ances ( two physically connect$ suns w\ld produce m>k$ *anges 9 ! int5sity ( ! tides rais$ ^u ea* ( !m by _! mutual gravitational attraction & unusual outbur/s ( gases or electrical excitem5t 9 ! atmosph]es ( ! />s might cause v noticeable *anges 9 ! color ( ^! />s z !y drew ne>] to ea* o!r1 :i* w\ld subside z !y rec$$ t[>d apa/ron4 ,9 addition to visual d\ble or multiple />s1 !re exi/s a v ext5sive class ( />s kn[n z spectroscopic b9>ies1 9 :i* ! two compon5ts are s close to ea* o!r t ev5 ! mo/ p[]ful telescopes _c divide !m4 ,x is only f ! %ift+ ( ! l9es ( _! ov]lapp+ spectra1 caus$ by _! alt]nate motion t[>d & f ! e>? z !y revolve ab\t _! common c5t] ( gravity1 t _! duplex nature is reveal$ to u4 ,9 "s in/ances "o memb] ( ! sy/em is s fa9t t its spectrum is n visible & its pres5ce is disclos$ only by ! %ift+ ( ! l9es ( ! bright />4 ,accord+ to ,doppl]'s ,law1 :5 a /> is approa*+ ! e>? ! l9es ( its spectrum %ift t[>d ! blue end ( ! spectrum1 & :5 ! /> is rec$+ f ! e>? ! l9es are %ift$ t[>d ! r$ end ( ! spectrum4 ,! am\nt ( ?is %ift c be v accurately measur$1 & gives ! relative velocities ( ! />s 9 _! orbits directly 9 miles p] second4 ,kn[+ 9 addition1 by obs]vation1 ! p]iod ( mutual revolution ( ! />s1 x is possible to f9d ! dim5sions ( ^! spectroscopic b9>y sy/ems comp>$ to our own sol> sy/em1 & also ! masses ( ! />s comp>$ to ! mass ( our own sun4 ,if ! spectrum ( ! fa9t] /> is n visible1 only ! velocity ( ! bright] /> ) respect to ! c5t] ( gravity ( ! sy/em c be f\nd & ! mass f\nd = ! sy/em comes out too small4 ,9 su* cases we c obta9 only a l[] limit = ! mass ( ! sy/em4 ,!n1 too1 x mu/ be rememb]$ t ^! sy/ems ( />s lie at all angles ) ref]5ce to our l9e ( sight1 & s we r>ely see ! orbits 9 _! true =m4 ,! measur$ velocities are z a result small] ?an ! true velocities1 & on ! av]age am\nt to only sixty p] c5t4 ( ! true orbital velocities4 ,! calculat$ masses ( spectroscopic b9>y />s are1 !re=e1 9 g5]al only ab\t sixty p] c5t4 ( ! true masses4 ,x has be5 f\nd f calculat+ ! masses ( a numb] ( b9>y sy/ems1 t ! comb9$ masses ( ! />s 9 ^! sy/ems d n diff] v greatly among !mselves1 nor z comp>$ to our own sun1 ?\gh 9 light-giv+ p[] ^! />s may diff] hundr$s1 ?\s&s1 ev5 millions ( times4 ,= in/ance1 !re are />s t give only "o t5-?\s&? "p ( ! light ( our own sun1 & o!r />s t give t5 ?\s& times z mu* light z ! sun4 ,moreov]1 !re are _m in/ances ( physically connect$ />s diff]+ ?\s&s ( times 9 lum9osity1 ?\gh 9 mass1 or quantity ( matt] f\nd 9 ! />s1 !y diff] only two or ?ree times4 ,:y ?is is s rema9s "o ( ! great my/]ies ( ! heav5s1 & makes x extremely difficult to give any satisfactory !ory ( ! orig9 ( d\ble-/> sy/ems4 ,x has nev] be5 expla9$ satisfactorily :y ( two suns physically connect$ &1 !re=e1 presumably orig9at+ at ! same "t1 "o %\ld be radiat+ ) ! greate/ int5sity1 :ile ! o!r is practically an ext9ct sun1 9 spite ( ! fact t ! quantity ( matt] 9 ! two bodies diff]s b slightly4 ,9 a few sy/ems ! plane 9 :i* ! />s revolve passes s ne>ly ?r\gh ! e>? t ! two />s tempor>ily eclipse "o ano!r dur+ ea* revolution4 ,su* sy/ems are call$ eclips+ b9>ies4 ,to su* a sy/em belongs ! fam\s ,algol4 ,its light waxes & wanes p]iodically ) ! greate/ punctuality 9 a p]iod ( #b;d #bj;h #dh4im1 ow+ to its tempor>y eclipse by a v l>ge b extremely fa9t att5dant sun4 ,! diamet] ( ! fa9t /> is slightly great] ?an ! diamet] ( ! bright /> :i* is ab\t "o million miles 9 ext5t4 ,! di/ance betwe5 ! c5t]s ( ! />s is only ab\t ?ree million miles1 :i* br+s _! surfaces )9 two million miles ( ea* o!r4 ,! masses ( ! two />s are 9 ! ratio ( two to "o1 ! bright] & m massive /> be+ ab\t half z heavy z our own sun1 ?\gh its d5sity is only ab\t two-t5?s t ( ! sun4 ,! d5sity ( ! fa9t] /> is /ill less1 be+ only ab\t half t ( ! bright] />4 ,v l[ d5sity ( bo? compon5ts & extreme fa9tness ( "o memb] comp>$ to ! o!r1 appe>s to be a v g5]al *>act]i/ic ( closely associat$ eclips+ & spectroscopic b9>y />s4 ,among ! extremely hot & brilliant helium & hydrog5 />s1 spectroscopic b9>ies exi/ 9 great numb]s4 ,9 fact1 among ^! types !re appe> to be z _m b9>y & multiple sy/ems z !re are sy/ems ( isolat$ suns4 ,sometimes ^! close b9>y />s are egg-%ap$ or oval & revolve rapidly almo/ 9 contact ab\t _! common c5t] ( gravity4 ,inhabitants ( satellites ( su* a sy/em w\ld see 9 _! heav5s !1 to u1 /range & />tl+ ph5om5on ( two suns1 ea* equal to our own or ev5 great] 9 size1 :irl+ rapidly ab\t ea* o!r & sep>at$ by a space comp>able 9 ext5t to _! own diamet]s4 ,eclipses 9 su* a sy/em w\ld be ( daily occurr5ce1 &1 if "o /> 7 d>k1 w\ld produce = ! satellite _w ! same effect ( alt]nate day & night t results f axial rotation ( a satellite4 ,! two hemisph]es ( ! fa9t companion sun w\ld be v unequally illum9at$ ow+ to ! fact t ! side turn$ t[>d ! brilliant sun w\ld always reflect its neighbor's brightness 9 addition to %9+ ) its own comp>atively feeble inh]5t light1 :ile ! opposite hemisph]e w\ld %9e only by its own dim light1 & w\ld1 !re=e1 be 9 comp>ative d>kness4 ,! spectroscopic b9>ies g5]ally revolve closely & rapidly ab\t _! common c5t] ( gravity2 !re are to be f\nd1 on ! o!r h&1 among ! wid] visual d\bles1 _m sy/ems :]e9 ! compon5ts are sep>at$ by di/ances comp>able to ! di/ances ( ! out] planets1 ,saturn1 ,uranus & ,neptune1 f ! sun4 ,x is evid5t t ! individual />s ( su* b9>y sy/ems c\ld n possibly be encircl$ by any su* ext5sive sy/em ( satellites z att5ds our own sun1 ?\gh satellites su* z our own planet ,e>?1 or ! inf]ior planets ,m]cury & ,v5us1 might conceivably encircle ! individual compon5ts ( su* b9>y sy/ems at di/ances n great] ?an t ( ! e>? f ! sun4 ,no planet c\ld safely exi/ at a mu* great] di/ance f "o ( ^! suns )\t be+ subject to mo/ dang]\s p]turbations & disruptive tidal =ces aris+ f ! vic9ity ( ! second sun4 ,grant$ t planets might encircle "o ( ^! suns at a di/ance approximat+ t ( ,v5us or our own planet f ! sun1 ! inhabitants ( su* worlds w\ld behold ! /range ph5om5on ( two suns 9 ! heav5s1 n almo/ 9 contact z 9 spectroscopic b9>y sy/ems1 b at "o "t comp>atively ne> & aga9 9 opposite portions ( ! heav5s z is ! case ) ! sun & moon 9 our own heav5s4 ,z ! planet advanc$ 9 its orbit ab\t ! rul+ sun1 ! second>y sun w\ld be visible at fir/ by day & aga9 by night4 ,if ! two suns 7 ( contra/+ hues1 z1 = in/ance1 gre5 & r$1 !re might appe> 9 ! ne>by heav5s at a di/ance ( "o hundr$ million miles or s a magnific5t sun ( deep r$di% hue1 equal to or surpass+ our own 9 spl5dor1 :ile 9 a f> di/ant "p ( ! sky1 at a di/ance z great z t :i* sep>ates u f ! planet ,saturn1 might appe> a rival sun ( gre5i% hue1 small] & fa9t]1 b nev]!less1 hot & extremely brilliant & capable ( ex]t+ ?r\gh its great gravitational attraction a mo/ di/urb+ effect ^u ! motion ( ! planet ( its neighbor4 ,at times ! rays ( ! two suns1 r$ & gre51 w\ld comb9e to produce a day *>act]iz$ by t]rific heat & int5se illum9ation4 ,aga9 ! gre5 orb w\ld rise 9 ! ea/ z ! r$ sun set 9 ! we/ & night w\ld be turn$ into a weird1 dimly-light$ day by ! gre5i% rays ( ! second>y sun4 ,comp>$ to ! wond]s & beauties ( ! heav5s 9 su* a sy/em1 our own well-regulat$ & ord]ly planet family1 undi/urb$ by ! excit+ proximity ( a rival sun1 seems to pale into insignificance4 ,yet we h e good reason to be cont5t ) ! ord]+ ( affairs )9 our own sol> sy/em1 & to feel relief r ?an regret at ! abs5ce ( a second>y sun4 ,9 a planet _w revolv+ ab\t "o memb] ( a d\ble /> sy/em1 we may imag9e ! dread r ?an pleasure ) :i* ! p]iodic ne>-approa* ( a rival sun w\ld be hail$1 & ev5 ! possible hurri$ migration f expos$ to %elt]$ portions ( ! planet>y _w to escape ! rapidly increas+ heat & int5sity ( light f ! approa*+ sun4 ,9 su* sy/ems ! com+ & go+ ( ! seasons might inde$ be a matt] ( life & dea? to ! inhabitants ( satellite worlds6 ,)9 our sol> sy/em ! masses ( ! planets are practically negligible comp>$ to ! mass ( ! sun1 & x is = ?is reason t !y appe> to revolve ab\t ! c5t] ( ! sun4 ,z a matt] ( fact1 no body 9 ! univ]se revolves ab\t ! exact geometrical c5t] ( ano!r body1 b two mutually attract+ bodies revolve 9 orbits ab\t _! common c5t] ( gravity1 :i* always lies betwe5 ! two bodies on ! l9e connect+ !m & at a di/ance f ea* ( !m t is 9 inv]se proportion to ! mass ( ! body4 ,! moon does n revolve ab\t ! c5t] ( ! e>?1 b ab\t ! c5t] ( gravity ( ! e>? & moon1 :i* lies on ! l9e connect+ ! two bodies & at a di/ance f ! e>?'s c5t] t is "o eighty-fir/ ( ! di/ance f ! c5t] ( ! e>? to ! c5t] ( ! moon1 s9ce ?is repres5ts ! ratio ( ! masses ( ! two bodies4 ,?is c5t] ( gravity ( ! e>? & moon1 lies1 !n1 ab\t two ?\s& miles f ! e>?'s c5t]1 & ab\t ?is po9t bo? e>? & moon trace out orbits ( revolution t are id5tical 9 =m & diff] only 9 size4 ,9 ! same way ea* ( ! planets ( ! sol> sy/em revolves ab\t ! c5t] ( gravity ( itself & ! sun1 b ! mass ( ! sun is s f> 9 excess ( ! comb9$ masses ( all ! planets t we may consid]1 = all practical purposes1 t ! planets revolve ab\t ! sun's c5t]1 ! c5t] ( gravity ( ! sy/em be+ )9 ! sun1 j z ! c5t] ( gravity ( ! e>? & moon is )9 ! e>?4 ,pr(4 ,t4 ,j4 ,j4 ,see f\nd f ! inve/igation ( =ty b9>y /> orbits t ! av]age ecc5tricity ( d\ble /> orbits is twelve times z great z ! av]age ecc5tricity ( a planet>y orbit1 & t ! masses ( ! compon5t suns nev] diff] v greatly4 ,! c5t] ( gravity ( a b9>y sy/em1 !re=e1 lies at a great di/ance f ! c5t]s ( ! />s1 & ab\t ?is po9t1 z a focus1 ! />s move 9 orbits t are exactly simil> 9 =m b diff] 9 size 9 inv]se proportion to ! ratio ( ! masses4 ,s9ce ! orbits ( b9>ies are1 moreov]1 v highly ecc5tric1 ! two suns are1 z we h said1 any:]e f two to n9ete5 times ne>] to ea* o!r at p]ia/ron ?an !y are at apa/ron4 ,we h spok5 s f> only ( sy/ems ( two associat$ suns1 b _m sy/ems exi/ 9 :i* ?ree or m sun-l bodies are 9 revolution ab\t a common c5t] ( gravity4 ,frequ5tly two fairly close suns are 9 revolution ab\t a common c5t] ( gravity1 9 a p]iod1 say1 ( fifty or sixty ye>s1 :ile a ?ird sun revolves at a comp>atively great di/ance ab\t ! c5t] ( gravity ( itself & ! fir/ pair 9 a p]iod ( sev]al hundr$ ye>s4 ,or possibly ! ?ird sun also possesses a close att5dant & ! two pairs revolve 9 a p]iod ( great l5g? ab\t a common c5t] ( gravity4 ,su*1 = in/ance1 are ! sy/ems ( ,zeta ,cancri & ,epsilon ,lyr4 ,9 ! =m] sy/em ! clos] compon5ts revolve rapidly ab\t _! c5t] ( gravity 9 a p]iod ( ab\t sixty ye>s1 :ile ! remote companion %[s irregul>ities 9 its motion t indicate t x is revolv+ ab\t a d>k body 9 a p]iod ( sev5te5 & a half ye>s1 :ile ! two toge!r are revolv+ v sl[ly 9 a p]iod ( six or sev5 c5turies1 ab\t a common c5t] ( gravity ) ! fir/ pair 9 a retrograde direction4 ,! wid] pair ( ,epsilon ,lyr is a nak$-eye d\ble = x c be se5 z a d\ble /> by a ke5 eye1 :ile ev5 a ?ree-in* telescope w sep>ate ea* ( ! compon5ts into a d\ble />4 ,s ext5sive is ?is sy/em t ! p]iods ( revolution ( ! clos] compon5ts occupy sev]al c5turies1 "o pair appe>+ to revolve ab\t twice z rapidly z ! o!r1 :ile ! p]iod ( revolution ( ! two pairs ab\t a common c5t] is probably a matt] ( ?\s&s ( ye>s4 ,! gap t sep>ates ! two pairs may be s great t light requires mon?s to cross x4 ,^! multiple sy/ems are by no means exceptional4 ,!y are to be f\nd 9 pr(usion among ! brilliant ,orion />s4 ,!y h be5 ref]r$ to z knots ( />s & x has be5 sugge/$ t !y may h orig9at$ z local cond5sations 9 "o va/ nebul\s tract4 ,a sy/em ( only two compon5ts appe>s to be ! exception r ?an ! rule1 gr\ps ( sev]al connect$ suns be+ m num]\s ?an s+le pairs4 ,9 all ( ^! d\ble & multiple sy/ems !re exi/s ! possibility ( m9ute satellites1 su* z our own e>?1 9 att5dance ^u "s "o compon5t ( ! sy/em4 ,su* t9y bodies %9+ only by reflect$ light f a ne>by brilliant sun w\ld be hopelessly invisible 9 ! mo/ p[]ful telescope4 ,we c only assume t x is f> m reasonable to believe 9 ?an to disprove ! exi/5ce ( su* satellites4 ,our own sol> sy/em1 !n1 repres5ts nei!r 9 its me*anical nor physical features1 ! only possibilities = ! ma9t5ance ( life2 x c nei!r be consid]$ a unique =m1 nor ev5 ! mo/ g5]ally preval5t =m 9 ! univ]se4 ,,xxx ,,a/ronomical ,,di/ances ,! gr&eur ( ! scale ^u :i* ! visible univ]se is fa%ion$ lies almo/ beyond human compreh5sion4 ,9 measur+ ! va/ ext5t ( our own sol> sy/em1 :i* is b a s+le unit 9 ! sy/em ( ! />s1 we may h rec\rse to "s e>?ly /&>d ( measurem5t1 su* z ! mile4 ,b :5 we desire to express 9 t]ms ( units t c be grasp$ by our imag9ation1 ! di/ances ( ! />s t lie f>1 f> beyond1 we f9d t all ord9>y /&>ds ( measurem5t become utt]ly inadequate = our purpose4 ,9 ! measurem5t ( cele/ial di/ances )9 ! sol> sy/em ! unit employ$ is ei!r ! famili> mile or kilomet] or ! a/ronomical unit1 :i* is ! mean di/ance f ! e>? to ! sun 7n9ety-two million n9e hundr$ ?\s& miles 9 r\nd numb]s74 ,9 ! measurem5t ( di/ances beyond ! sol> sy/em ! unit employ$ is ei!r ! light-ye> or m rec5tly ! p>sec1 :i* is rapidly replac+ ! light-ye> among a/ronom]s4 ,a light-ye> is ! di/ance t light1 ) its f9ite b almo/ unimag9able velocity ( "o hundr$ & eighty-six ?\s& miles p] second1 travels 9 a ye>4 ,x is equal 9 r\nd numb]s to sixty-?ree ?\s& times ! di/ance f ! e>? to ! sun or approximately six ?\s& billions ( miles4 ,! p>sec is equal to ?ree & tw5ty-six hundr$?s 7#c4bf7 light-ye>s1 & x is approximately two hundr$ ?\s& times ! di/ance f ! e>? to ! sun4 ,x is ! di/ance ( a /> ) ! p>allax ( a second1 a fact :i* its "n1 p>sec1 conveys to u4 ,9 o!r words1 at ! di/ance ( "o p>sec ! di/ance f ! e>? to ! sun1 ! a/ronomical unit1 w\ld subt5d an angle equal to "o second ( an arc4 ,?is angle is spok5 ( z ! p>allax ( ! />4 ,! l>g] ! p>allax1 t is1 ! l>g] ! angle ! a/ronomical unit or radius ( ! e>?'s orbit subt5ds1 view$ f ! />1 ! ne>] ! /> is to u4 ,! fact t !re is no kn[n /> )9 "o p>sec1 or ?ree & tw5ty-six hundr$?s light-ye>s1 ( ! sun %[s ! imm5sity ( ! scale ( ! univ]se ( />s4 ,be=e consid]+ ! di/ances ( ! />s & ! ext5t ( ! sid]eal sy/em ( :i* our sun & 8 satellites =m a "p1 let u und]take to express ! di/ance ( ! sun1 moon & planets f ! e>? & ! ext5t ( ! sol> sy/em 9 t]ms ) :i* we are famili>4 ,! ne>e/ to ! e>? ( all cele/ial bodies is its satellite1 ! moon4 ,s ne> is ! moon t if we %\ld make on "s great pla9 a model ( ! sol> sy/em 9 :i* ! a/ronomical unit1 ! di/ance f e>? to sun1 w\ld be f\r hundr$ feet1 ! di/ance betwe5 ! e>? & moon w\ld be only "o foot4 ,on ! same scale ! mo/ di/ant planet ,neptune w\ld be two & "o-qu>t] miles away4 ,grant$ t x 7 possible to escape ! e>?'s gravitational bonds & to travel by our swifte/ means ( conveyance1 ! airplane1 ?r\gh int]planet>y space1 let u consid] h[ long x w\ld take u to rea* ! moon1 sun & planets if our spe$ 7 ma9ta9$ at a uni=m rate ( two hundr$ miles an h\r4 ,an airplane travel+ at ?is rate w\ld circumnavigate ! e>? 9 a little ov] five days & w\ld rea* ! moon 9 sev5 weeks4 ,a trip to ! sun1 h[ev]1 w\ld take fifty-?ree ye>s4 ,aft] travel+ = f\rte5 & a fraction ye>s we w\ld pass ! orbit ( ,v5us & eighte5 ye>s lat] ! orbit ( ,m]cury4 ,if we pref]r$ to travel outw>d f ! e>? 9 ! direction ( ,m>s & ! out] planets in/ead ( t[>d ! sun1 m ?an tw5ty-sev5 ye>s w\ld elapse be=e we w\ld rea* ! orbit ( ,m>s4 ,an airplane j\rney to ,jupit] w\ld be a matt] ( m ?an two hundr$ ye>s1 to ,saturn f\r hundr$ & fifty ye>s1 to ,uranus ne>ly "o ?\s& ye>s1 & to ,neptune1 ab\t "o ?\s& five hundr$ ye>s4 ,to cross ! sol> sy/em on ! diamet] ( ,neptune's orbit 9 an airplane1 travel+ day & night )\t /opp+ at ! rate ( #bjj miles p] h\r w\ld take m ?an ?ree ?\s& ye>s4 ,! sun's attraction rea*es f> beyond ,neptune's orbit1 h[ev]4 ,!re are comets belong+ to ! sol> sy/em compell$ by ! sun's attraction to accompany him on 8 travels ?r\gh space t return p]iodically to ! imm$iate vic9ity ( ! sun f regions f> beyond ! orbit ( ,neptune & !re is also ! possibility t "o or m undiscov]$ planets may travel ar\nd ! sun 9 orbits f> ext]ior to ,neptune's orbit4 ,measur$ 9 t]ms ( famili> units1 su* z are employ$ = ! measurem5t ( di/ances on our own planet1 ! ext5t ( ! sol> sy/em is trem5d\sly great4 ,view$ f ,neptune1 ! sun is s f> away t x pres5ts no appreciable disk4 ,x is 9 ?is s5se />-l to ! ,neptunians1 b at ! di/ance ( ,neptune ! />s appe> no m brilliant & no ne>] ?an !y d to u4 ,to ,neptune ! sun1 ?\gh />-l 9 =m1 supplies a v appreciable quantity ( light & heat 7"o n9e-hundr$? ( ! am\nt ! e>? receives7 :ile ! am\nt ( light & heat t ,neptune receives f ! ne>e/ />s is entirely inappreciable4 ,:5 our airplane rea*es ,neptune aft] a j\rney ( "o ?\s& five hundr$ ye>s1 x is1 z x 71 j cle>+ ! gr\nd = its flight to ! />s4 ,to cov] ! int]v5+ space to ! ne>e/ />1 travel$ by light 9 f\r & a ?ird ye>s1 an airplane w\ld ne$ f\rte5 & a half million ye>s4 ,9 t "t ! sol> sy/em itself w\ld be 9 "s f> di/ant "p ( ! univ]se1 s9ce x is spe$+ onw>d ?r\gh space at ! rate ( twelve miles a second or ab\t f\r a/ronomical units a ye>4 ,*ang+ n[ our unit ( measurem5t t we may express int]/ell> di/ances 9 compreh5sible numb]s1 we prep>e to travel f ! e>? to ! />s ) ! velocity ( light4 ,) ?is velocity1 "o hundr$ & eighty-six ?\s& miles p] second1 we circumnavigate our globe 9 "o-sev5? ( a second1 rea* ! moon 9 "o & a f\r? seconds & ! sun 9 eight m9utes4 ,9 a little ov] f\r h\rs we pass ! orbit ( ,neptune & are />t$ on our j\rney to ! />s1 p5etrat+ fur!r & fur!r into int]/ell> space4 ,= a ye> we travel & rea* n a s+le /> ?\gh we are spe$+ ev] onw>d ) ! velocity ( light4 ,we h n[ cov]$ ! di/ance ( "o light-ye>1 :i* means t ! waves ( light f ! sun we h left beh9d mu/ travel = a ye> be=e !y rea* u4 ,we cont9ue our j\rney & f9d ourselves next at a di/ance ( "o p>sec f ! sun4 ,we h travel$ a di/ance ( approximately ?ree & a qu>t] light-ye>s1 & 7 x possible to see ! e>? z well z ! sun at ?is di/ance1 ! two w\ld appe> to be b "o second ( arc ap>t1 a di/ance t requires ! mo/ c>eful adju/m5t & manipulation ( ! telescope to measure accurately4 ,we are /ill "o light-ye> di/ant f ,alpha ,c5tauri1 ! ne>e/ ( ! bright />s4 ,a few ( ! />s w n[ appe> some:at bright] ?an !y appe>$ to u on e>?1 b ! majority ( ! />s appe> j z we see !m "h & ! =ms ( ! con/ellations rema9 practically un*ang$ 9 appe>ance1 = we are only beg9n+ our j\rney ?r\gh ! sid]eal univ]se & our position 9 x has only %ift$ by a v slight am\nt4 ,if we %\ld cont9ue our j\rney to ! imm$iate vic9ity ( ,alpha ,c5tauri1 we w\ld f9d t x is n l our own sun1 a s+le />1 b is a b9>y /> consi/+ ( two suns 9 revolution ar\nd _! common c5t] ( gravity4 ,! di/ance ( ?is b9>y sy/em f ! sol> sy/em has be5 measur$ ) consid]able accuracy & is kn[n to be f\r & a ?ird light-ye>s4 ,?\gh !re may be a few fa9t />s or non-lum9\s />s ne>] to u ?an ,alpha ,c5tauri1 ?is /> has long held ! di/9ction ( be+ ! ne>e/ ( ! />s4 ,z ! sun cont9ues 8 j\rney ?r\gh ! univ]se ! two />s1 ,alpha ,c5tauri & our sun1 w f9ally draw away f ea* o!r aft] _m ages h pass$ & "s o!r sun ( space w be our ne>e/ />4 ,! di/ances t sep>ate ! />s f ea* o!r probably av]age z great z ! di/ance f ! sun to ,alpha ,c5tauri4 ,)9 a sph]e ^: c5t] is at ! e>? & ^: radius is five p>secs1 or ab\t sixte5 light-ye>s1 !re are only ab\t tw5ty kn[n />s4 ,!re is1 !re=e1 small *ance ( collision among bodies t are s small 9 proportion to ! trem5d\s int]vals ( space t sep>ate !m f ea* o!r4 ,!re is ample room = ! individual />s to pursue _! j\rney ?r\gh space )\t int]f]+ ) ea* o!r's motion s long z !y are z widely scatt]$ z !y appe> to be 9 ?is portion ( ! univ]se4 ,! fact t our own sun has cont9u$ its j\rney ?r\gh ! univ]se = "s hundr$s ( millions ( ye>s )\t any cata/rophe su* z w\ld result f closely approa*+ or collid+ ) ano!r sun ( space %[s h[ enorm\s is ! scale ^u :i* our sid]eal sy/em is fa%ion$4 ,/>s t are t51 fifty or ev5 "o hundr$ light-ye>s f ! e>? are our ne>e/ neighbors 9 space4 ,!y are ! />s t %[ a slight displacem5t 9 ! heav5s or measurable p>allax1 view$ f opposite sides ( ! e>?'s orbit4 ,!re are probably a ?\s& />s among ! hundr$s ( millions ( />s )9 rea* ( ! greate/ telescopes ^: di/ances h be5 det]m9$ 9 light-ye>s by direct measurem5t ( _! displacem5t 9 ! heav5s result+ f ! *ange ( position ( ! e>? 9 its orbit4 ,! mo/ di/ant ( ! />s are app>5tly immovable 9 ! heav5s %[+ nei!r ! effect ( ! sun's motion or _! own motion ?r\gh space4 ,me?ods = f9d+ ! di/ances ( _m f> remote />s & />-clu/]s h be5 devis$1 h[ev]1 & "s comp>atively rec5t inve/igations h giv5 results = ! di/ances ( ^! objects indicat+ t ! diamet] ( ! sy/em ( />s to :i* our sun belongs is approximately ?ree hundr$ ?\s& light-ye>s4 ,x is difficult to grasp ! full significance ( ?is fact4 ,x means t hundr$s ( millions ( ! suns ( space ?rong ! visible univ]se at di/ances f u & f ea* o!r runn+ into hundr$s1 ?\s&s & ev5 hundr$s ( ?\s&s ( light-ye>s4 ,! light waves f "s t9y object t we view today 9 "o ( our great reflectors may h />t$ on _! j\rney ?r\gh space ov] "o hundr$ ?\s& ye>s ago :5 m5 ( ! ,old ,/one ,age inhabit$ our planet e>?6 ,a/ronom]s h f\nd z a result ( _! inve/igations t ! sid]eal sy/em to :i* our sol> sy/em belongs is 9 ! =m ( a flatt5$ sph]oid ) its longe/ axis 9 ! plane ( ! ,milky ,way4 ,! ext5t ( ?is /> sy/em compos$ ( hundr$s ( millions ( individual suns 9 addition to nebul & clu/]s is probably some?+ l ?ree hundr$ ?\s& light-ye>s along its longe/ axis1 :ile globul> /> clu/]s ly+ above & bel[ its c5tral plane are e/imat$ to be at di/ances f x rang+ f t5 ?\s& to two hundr$ ?\s& light-ye>s4 ,?is entire organiz$ sy/em is our sid]eal univ]se4 ,space beyond is unexplor$4 ,! globul> /> clu/]s are among ! mo/ di/ant cele/ial objects s f> discov]$4 ,! spiral nebul may be entirely )9 ! limits ( ?is sy/em or !y may be ev5 m di/ant ?an ! globul> clu/]s = _! di/ances are n kn[n z yet4 ,!re is a possibility t our sid]eal univ]se1 va/ z x is kn[n to be1 may be b a unit 9 "s /ill great] unit & t o!r simil> sy/ems lie beyond ! rea* ( exi/+ telescopes at unimag9able di/ances4 ,! m9d ( man is ov]:elm$ by ! ?\ght ( sid]eal sy/ems z va/ z our own ly+ f> beyond 8 k54 ,:e!r or n su* ext]nal sy/ems d exi/ & are ) our own sid]eal sy/em units 9 "s /ill va/] creation we _c "k4 ,s va/1 inde$1 is ?is "o visible univ]se ( ours t ! m9d ( man1 accu/om$ to e>?ly /&>ds1 _c compreh5d its magnitude or ! inf9itesimal size ( our :ole sol> sy/em comp>$ to x4 ,,xxxi ,,"s ,,a/ronomical ,,facts ,,wor? ,,rememb]+ ,kepl]'s ,?ree ,laws ( ,planet>y ,motion3 ,i4 ,! planets move 9 ellipses ) ! sun at "o focus4 ,,ii4 ,! radius vector ( a planet 7l9e adjo9+ sun & planet7 sweeps ov] equal areas 9 equal times4 ,,iii4 ,! squ>e ( ! "t ( revolution 7! ye>7 ( ea* planet is proportional to ! cube ( its mean di/ance f ! sun4 99 99 99 99 99 ,sir ,isaac ,newton discov]$ t ! law ( gravitation ext5ds to ! />s4 ,t is1 e mass 9 ! univ]se attracts e o!r mass ) an attraction directly proportional to ! product ( ! masses & inv]sely proportional to ! squ>e ( ! di/ances betwe5 !m4 99 99 99 99 99 ,ocean tides are caus$ by ! diff]5ce betwe5 ! attraction ( ! sun & moon = ! ma9 body ( ! e>? & _! attraction = diff]5t p>ticles ( ! e>?'s surface4 ,! tide-rais+ =ce ( ! di/urb+ body is proportional to its mass & inv]sely proportional to ! cube ( its di/ance4 ,! tides produc$ by ! sun are1 !re=e1 only two-fif?s z great z ! tides produc$ by ! moon4 99 99 99 99 99 ,! cele/ial sph]e is an imag9>y sph]e ( inf9ite radius1 ) ! e>? at its c5t]1 ^u :i* ! cele/ial bodies are consid]$ to be project$ = conv5i5ce 9 det]m9+ _! positions ) respect to fix$ po9ts ( ref]5ce 9 ! heav5s4 ,! nor? & s\? poles ( ! heav5s are ! po9ts on ! cele/ial sph]e directly above ! nor? & s\? poles ( ! e>?4 ,! cele/ial equator is ! great circle 9 :i* ! plane ( ! e>?'s equator int]sects ! cele/ial sph]e4 ,x passes ?r\gh ! ea/ & we/ po9ts ( ! horizon & ?r\gh ! z5i?--or po9t directly ov]head--at ! e>?'s equator4 ,! ecliptic is ! great circle 9 :i* ! plane ( ! e>?'s orbit int]sects ! cele/ial sph]e4 ,! cele/ial equator & ! ecliptic are incl9$ to ea* o!r at an angle ( #bc-a_/b1 :i* is call$ ! obliquity ( ! ecliptic4 ,! two po9ts 9 :i* ! cele/ial equator & ! ecliptic int]sect are call$ respectively ! v]nal equ9ox & ! autumnal equ9ox4 ,! v]nal equ9ox is an important po9t ( ref]5ce on ! cele/ial sph]e4 ,z ! position ( a po9t on ! e>?'s surface is det]m9$ by its longitude & latitude s ! position ( an object on ! cele/ial sph]e--/>1 sun1 planet--is det]m9$ by its ,"r ,asc5sion & ,decl9ation4 ,! ,decl9ation ( a cele/ial object is its di/ance nor? or s\? ( ! cele/ial equator1 measur$ 9 degrees1 m9utes & seconds ( arc1 on a great circle ( ! cele/ial sph]e pass+ ?r\gh ! object & nor? & s\? poles ( ! heav5s4 ,^! great circles are call$ h\r circles & !y correspond to ! m]idians or circles ( longitude on ! e>?'s surface4 ,! decl9ation ( an object 9 ! heav5s corresponds to ! latitude ( a po9t on ! e>?'s surface4 ,! ,"r ,asc5sion ( a po9t on ! cele/ial sph]e corresponds to ! longitude ( a po9t on ! e>?'s surface4 ,x is measur$--z longitude is measur$--9 degrees1 m9utes & seconds ( arc or 9 h\rs1 m9utes & seconds ( "t--ea/w>d along ! cele/ial equator f ! h\r circle pass+ ?r\gh ! v]nal equ9ox to ! foot ( ! h\r circle pass+ ?r\gh ! object4 ,! h\r circle pass+ ?r\gh ! v]nal equ9ox is ! z]o m]idian = ! cele/ial sph]e j z ! m]idian ( ,gre5wi* is ! z]o m]idian on ! e>?'s surface4 99 99 99 99 99 ,! mean di/ance ( ! e>? f ! sun is #ib1ijj1jjj miles & is call$ ! a/ronomical unit4 ,! sun ) its satellites advances ?r\gh ! univ]se at ! rate ( #d a/ronomical units 9 a ye> or approximately "o million miles a day4 ,! p>allax ( a /> is ! angle at ! /> subt5d$ by ! radius ( ! e>?'s orbit1 #ib1ijj1jjj miles1 or ! a/ronomical unit4 ,x is1 9 o!r words1 ! angul> di/ance betwe5 ! e>? & sun z view$ f ! />4 ,! l>g] ! p>allax ! ne>] ! />4 ,! l>ge/ kn[n /ell> p>allax is t ( ,alpha ,c5tauri & its value is #j4ge4 ,! light-ye> is ! di/ance t light travels 9 "o ye>4 ,x is equal to ab\t #fc1jjj a/ronomical units or ne>ly six trillion 7#f1jjj1jjj1jjj1jjj7 miles4 ,! velocity ( light is #ahf1jjj miles p] second4 ,! p>sec is equal to #c4bf light-ye>s4 ,x is ! di/ance ( a /> t has a p>allax ( "o second ( arc4 ,! app>5t magnitude ( a /> is its app>5t brightness e/imat$ on a scale 9 :i* a diff]5ce ( "o magnitude corresponds to a diff]5ce 9 brightness ( #b4ea1 or ! fif? root ( "o hundr$4 ,a diff]5ce ( five magnitudes corresponds to a diff]5ce "o "o hundr$fold 9 brightness1 ( t5 magnitudes to t5 ?\s&fold 9 brightness4 ,9 exact measurem5ts on ?is scale magnitudes are e/imat$ to t5?s4 ,/>s t are "o magnitude bright] ?an />s ( ! /&>d fir/ magnitude are ( ! z]o magnitude & />s /ill bright] are ( negative magnitudes4 ,sirius is a /> ( ! -#a4f magnitude4 ,jupit] at opposition is ( -#b4j magnitude & ,v5us at greate/ brilliancy ( -#d4j magnitude4 ,! sun on ?is scale ( comp>ative brightness is ( ! -#bf4g app>5t magnitude4 ,! fa9te/ />s visible 9 ! mo/ p[]ful telescope 9 ! _w--! #aja-;in* ,mt4 ,wilson ,hook] telescope--are ( ! tw5tie? magnitude4 ,! absolute magnitude ( a /> is its app>5t magnitude at ! /&>d di/ance ( t5 p>secs or #cb4f light ye>s4 ,! absolute magnitude ( ! sun is five4 ,t is1 ! sun w\ld be a fif?-magnitude /> at ! /&>d di/ance ( #cb4f light-ye>s4 ,! absolute magnitudes ( />s indicate h[ bright !y w\ld be relatively if !y 7 all at ! same /&>d di/ance4 ,app>5t magnitudes indicate h[ bright ! />s appe> to be at _! true di/ances4 99 99 99 99 99 ,! mean di/ance ( ! moon f ! e>? is approximately #bdj1jjj miles or sixty times ! e>?'s radius4 ,! sun is f\r hundr$ times f>!r away ?an ! moon & its diamet] is ab\t f\r hundr$ times great] ?an ! moon's diamet]4 ,! ne>e/ /> is ab\t #bge1jjj times m di/ant ?an ! sun1 & ! mo/ di/ant kn[n object1 ! globul> /> clu/]1 ,n4,g4,c4 #gajf1 is ab\t f\rte5 billion times m di/ant ?an ! sun4 ,! e>? is a sph]oid flatt5$ at ! poles & its pol> diamet] is ab\t tw5ty-sev5 miles %ort] ?an its equatorial diamet]4 ,an object weighs less at ! poles ?an at ! equator4 ,! e>?'s int]ior is z rigid z /eel & probably consi/s ( a core ( magnetic iron surr\nd$ by an out] /ony %ell4 ,eclipses ( ! sun occur :5 ! moon passes betwe5 ! e>? & sun4 ,!y c only occur at ! "t ( new moon4 ,!re mu/ be at lea/ two sol> eclipses e ye> sep>at$ by an int]val ( six mon?s & !re may be z _m z five sol> eclipses 9 a ye>4 ,eclipses ( ! moon occur :5 ! e>? comes betwe5 ! sun & moon1 & ! moon passes into ! e>?'s %ad[4 ,eclipses ( ! moon c only occur at full moon4 ,!re may or may n be eclipses ( ! moon e ye>4 ,! greate/ numb] ( eclipses ?an c occur 9 any "o ye>1 sol> & lun> comb9$1 is sev5 & ! lea/ numb] is two & 9 t case !y are bo? sol> eclipses4 ,! sun is a yell[1 dw>f /> ( a d5sity ( "o & "o-f\r? t ( wat] & ) a surface temp]ature ( ab\t #ab1jjj ,f4 except 9 sun-spot regions :]e ! temp]ature is ab\t #f1jjj ,f4 ,x is probably gase\s ?r\gh\t4 ,! sun1 z well z ! planets1 rotates on its axis & diff]5t portions ( ! surface rotate at slightly diff]5t rates4 ,! av]age p]iod ( ! rotation ( ! sun on its axis is ab\t tw5ty-six days4 ,! sun is a v>iable /> ) a tw(old v>iation4 ,"o is ( long p]iod dur+ ! elev5-ye> sun-spot cycle ) a range ( f ?ree to five p] c5t4 ,! o!r is a %ort irregul> v>iation ) a p]iod ( a few days1 weeks or mon?s & a range ( f ?ree to t5 p] c5t4 ,sun-spots are sol> cyclones & appe> black only by contra/ ) _! hott] & bright] surr\nd+s4 ,!y come 9 elev5-ye> cycles 7approximately7 ) p]iods ( maximum & m9imum appe>ance4 ,! brightness & blue color ( ! sky is due to ! scatt]+ ( sunlight by ! molecules ( oxyg5 & nitrog5 9 ! e>?'s upp] atmosph]e4 ,if !re 7 no atmosph]e ! skies w\ld appe> black except 9 ! direction ( ! heav5ly bodies1 :i* w\ld be visible by day z well z by night4 ,! sol> corona is ! r>e out] envelope ( ! sun & x is visible only dur+ a total eclipse ( ! sun4 ,x is p>tly ( an electrical nature & x v>ies 9 =m dur+ ! sun-spot cycle4 ,x (t5 ext5ds to a di/ance ( sev]al sol> diamet]s on ei!r side ( ! sun4 ,! w>m? & ! habitability ( ! e>?'s surface is due to ! pres5ce ( wat]-vapor & c>bon-dioxide 9 ! atmosph]e4 ,)\t ^! sub/ances 9 ! atmosph]e life on ! e>?'s surface w\ld be impossible4 ,half ( ! e>?'s atmosph]e & all cl\ds lie )9 sev5 miles ( ! e>?'s surface1 & at high elevations above ! e>? ! temp]ature is _m degrees bel[ z]o4 ,! temp]ature ( space approa*es ! absolute z]o ( -#dei ,f4 ,! only planets 9 ! sol> sy/em ) ! exception ( ! e>? t might possibly support life are ,v5us & ,m>s4 ,/>s %9e by _! own light b planets %9e only by reflect$ light f ! sun4 99 99 99 99 99 ,if ! e>? 7 repres5t$ by a six-in* s*ool globe ! sun w\ld be on ! same scale a globe fifty-f\r feet 9 diamet]4 ,m]cury w\ld be a small ball two & a ?ird in*es 9 diamet]4 ,v5us w\ld be ano!r six-in* globe4 ,m>s w\ld be a ball ab\t ! size ( a baseball1 ?ree & a fif? in*es 9 diamet]4 ,! moon w\ld be ab\t ! size ( a golf ball1 "o & a half in*es 9 diamet]4 ,! l>ge/ a/]oids w\ld be ! size ( m>bles4 ,av]age-siz$ a/]oids w\ld be ! size ( %ot & ! smalle/ w\ld be m]ely gra9s ( s&4 ,jupit] w\ld be a huge globe /&+ z tall z a man five feet six in*es 9 height4 ,saturn w\ld be a small] globe f\r & a half feet 9 diamet] & its r+ sy/em w\ld ext5d to a di/ance ( five & a half feet on ei!r side ( ! globe4 ,uranus w\ld be repres5t$ by a globe almo/ exactly two feet 9 diamet] & ,neptune w\ld be a slightly l>g] globe ) a diamet] ( two feet two & a half in*es4 ,! satellites ( ! out] planets w\ld range 9 size f t5nis & golf balls = ! l>ge/1 to m>bles = ! small] & gra9s ( s& = ! smalle/4 ,on ! same scale ( measurem5t ! di/ance ( ! six-in* globe ( ! e>? f ! fifty-f\r foot globe repres5t+ ! sun w\ld be "o & "o-t5? miles4 ,! moon w\ld be plac$ fifte5 feet f ! e>?-globe & ! diamet] ( ! sol> sy/em on ! same scale measur$ across ! orbit ( ,neptune w\ld be sixty-six miles4 ,! ne>e/ /> on ?is scale w\ld be ?ree hundr$ ?\s& miles away4 99 99 99 99 99 ,if ! di/ance f ! e>? to ! sun is tak5 z "o in* s t ! scale ( ! univ]se is r$uc$ six trillion times1 ! diamet] ( ! sol> sy/em across ,neptune's orbit is five feet & ! di/ance ( "o light-ye> comes out almo/ exactly equal to "o mile4 ,! ne>e/ /> to ! five-foot sol> sy/em w\ld be f\r & a ?ird miles away2 ! mo/ di/ant kn[n object w\ld be two hundr$ & tw5ty ?\s& miles away1 & ! ext5t ( ! visible univ]se w\ld be ?ree hundr$ ?\s& miles4 ,on ! same scale ! diamet] ( our sun w\ld be ab\t "o hundr$? ( an in* & ! diamet]s ( ! giant />s ,ant>es & ,betelgeuze w\ld be f\r in*es & two & ?ree-f\r? in*es respectively4 ,to see ! e>? we w\ld ne$ a microscope4 ,,tables ,,table ,i ,,! ,,pr9cipal ,,elem5ts ,,( ,,! ,,sol> ,,sy/em ,mean ,di/ance f ,sun ,velocity --------------------- 9 ,incl9ation ,relative ,p]iod ,orbit ,ecc5tricity ( ,planet ,9 ,miles to ( 7,miles ( ,orbit to ,e>?'s ,revolution p] ,orbit ,ecliptic ,di/ance ,second 7 ---------------------------------------- ------------------------------------ ,m]cury #cf1jjj1jjj #j4ci #hg4ig days #bc to #ce 4#bjef #g #j' ,v5us #fg1bjj1jjj #j4gb #bbd4gj days #ba4i 4#jjfh #c #bc ,e>? #ib1ijj1jjj #a4jj #cfe4be days #ah4e 4#jafg #j #j ,m>s #ada1ejj1jjj #a4eb #a4hh ye>s #ae4j 4#jicc #a #ea ,a/]oids#a 44444444444#b4j-e4b 444444444 444444 4#jj to 4#dj #j to #ce ,jupit] #dhc1cjj1jjj #e4bj #aa4hf ye>s #h4a 4#jdhd #a #ah ,saturn #hhf1jjj1jjj #i4ed #bi4df ye>s #f4j 4#jeeh #b #bi ,uranus #a1gha1ijj1jjj #ai4ai #hd4jb ye>s #d4b 4#jdga #j #df ,neptune #b1iga1fjj1jjj #cj4jg #afd4gi ye>s #c4d 4#jjhe #a #dg ,,footnote3 #a ,ab\t #idj h be5 discov]$ up to ! pres5t "t4 ,,! ,,pr9cipal ,,elem5ts ,,( ,,! ,,sol> ,,sy/em 7,cont9u$7 ,mean ,d5sity ,surface ,velocity ,reflect+ ,p]iod ,incl9ation ,"n ,diamet] ,mass ,volume ,relative ,gravity ( ,escape ,p[] ( ( 9 --------------------to t 7,relative 7,miles p] 9 ,axial ,equator ,miles ,relative to ,e>?'s ( ,wat] to ,e>?'s7 ,second7 ,p] ,c5t ,rotation to ,orbit ---------------------------------------- ---------------------------------------- -------------------- ,sun #hfd1cib #cbi1cij #a1cjj1jjj #a4dj #bg4fd #chc 44444 #be d4 #h h4 #g #ae' ,moon #b1afj 4#jab 4#jb #c4cd #j4af #a4e #g #bg d4 #g4g h4 #f #da ,m]cury #c1jji 4#jde 4#jf #d4dh8 #j4ca8 #b4b #g #hh d4 8 8 ,v5us #g1ege 4#hjg 4#ib #d4he8 #j4he #f4f #ei 8 8 ,e>? #g1iah #a4jjj #a4jj #e4ec #a4jj #g #dd #bc h4 #ef m4 #bc #bg ,m>s #d1baf 4#ajf 4#ae #c4eh #j4ce #a4e #ae #bd #cg #bc #ei ,a/]oids#e-dhebv smallv small #c4c 4#jjjh to 4#jd4cc to 4#ja #g 44444 44444 ,jupit] #hh1cib #cad4ej #acji #a4be #b4eb #cg #ef #i #ee #c ,saturn #gd1afc #id4jg #gfj #j4fc #a4jg #bb #fc #aj #ad #bg ,uranus #cj1hgh #ad4dj #fe #a4dd #j4ii #ac #fc #aj #de 8 ,neptune #cb1icb #af4gb #he #a4ji #j4hg #ad #gc 8 8 ,,footnote3 #b ,extreme values4 ,,table ,,ii ,,! ,,satellites ,,( ,,! ,,sol> ,,sy/em ,mean ,di/ance ,app>5t f ,planet's,diamet] ,p]iod ( ,ye> ( ,"n ,magnitude ,c5t]1 9 miles ,revolution ,discov]] ,discov]y 9 miles ---------------------------------------- ---------------------------------------- ----- ,,! ,,e>? ,moon #bch1heg #bafj #bg days1 #g h\rs1 #dc m9utes ,,m>s #a4 ,phobos #ad #e1hej #aj8 #j days1 #g h\rs1 ,asaph ,hall #ahgg #ci m9utes #b4 ,deimos #ac #ad1fej #aj8 #a day1 #f h\rs1 ,asaph ,hall #ahgg #ag m9utes ,,jupit] v4 #ac #aab1ejj #ajj8 #j day1 #aa h\rs1 ,b>n>d #ahib #eg m9utes i4 #f4e #bfa1jjj #bdeb #a day1 #ah h\rs1 ,galileo #afaj #bh m9utes ii4 #f4e #dae1jjj #bjde #c days1 #ac h\rs1 ,galileo #afaj #ad m9utes iii4 #f #ffd1jjj #ceeh #g days1 #c h\rs1 ,galileo #afaj #dc m9utes iv4 #g #a1afg1jjj #ccde #af days1 #af h\rs1 ,galileo #afaj #cb m9utes vi4 #ad #g1cgb1jjj small #bff days1 #j h\rs1 ,p]r9e #aijd #j m9utes vii4 #af #g1efg1ijj v #bgf days1 #af h\rs1 ,p]r9e #aije small #e m9utes viii4 #ag #ae1fjj1jjj v #ghi days1 #j h\rs1 ,melotte #aijh small #j m9utes ix4 #ai #ah1ijj1jjj #bj8 #c ye>s ,ni*olson #aiad ,,saturn #a4 ,meimas #ae #aag1jjj #fjj #j days1 #bb h\rs1 ,h]s*el #aghi #cg m9utes #b4 ,enceladus #ad #aeg1jjj #hjj #a day1 #h h\rs1 ,h]s*el #aghi #ec m9utes #c4 ,te?ys #aa #ahf1jjj #abjj #a day1 #ba h\rs1 ,cass9i #afhd #ah m9utes #d4 ,dione #aa #bch1jjj #aajj #b days1 #ag h\rs1 ,cass9i #afhd #da m9utes #e4 ,rhea #aj #ccb1jjj #aejj #d days1 #ab h\rs1 ,cass9i #afgb #be m9utes #f4 ,titan #i #gga1jjj #cjjj #ae days1 #bb h\rs1 ,huyg5s #afee #da m9utes #g4 ,hyp]ion #af #icd1jjj #ejj #ba days1 #f h\rs1 ,bond #ahdh #ci m9utes #h4 ,japetus #aa #b1bbe1jjj #bjjj #gi days1 #g h\rs1 ,cass9i #afga #ed m9utes #i4 ,phoebe #ag #h1jjj1jjj #bjj8 #edf days1 #ab h\rs1 ,w4,h4 #ahih #j m9utes ,pick]+ #aj4 ,!mis #ag #ijf1jjj 8 #bj days1 #bj h\rs1 ,w4,h4 #aije #bd m9utes ,pick]+ ,,uranus #a4 ,ariel #ae #abj1jjj #ejj #b days1 #ab h\rs1 ,lassell #ahea #bi m9utes #b4 ,umbriel #af #afg1jjj #djj #d days1 #c h\rs1 ,lassell #ahea #bh m9utes #c4 ,titania #ac #bgc1jjj #ajjj #h days1 #af h\rs1 ,h]s*el #aghg #ef m9utes #d4 ,ob]on #ad #cfe1jjj #hjj #ac days1 #aa h\rs1 ,h]s*el #aghg #g m9utes ,,neptune #a4 ,nameless #ac #bba1ejj #bjjj #e days1 #ba h\rs1 ,lassell #ahdf #c m9utes ,,r+s ,,( ,,saturn ,di/ance ( ,di/ance ( ,diamet] ( ,r+ ,inn] ,edge f ,out] ,edge f ,sy/em f out] ,"n ,wid?1 ,surface ( ,saturn1 ,surface ( ,saturn1 edge to out] edge1 9 miles 9 miles 9 miles #agb1ejj miles4 ---------------------------------------- ---------------------------,?ickness ( ,r+ ,sy/em1 ab\t "o ,d>k or ,crape ,r+ #aj1ijj #e1ijj #af1hjj hundr$ miles4 ,bright ,r+ #ah1jjj #af1hjj #cd1hjj ,size ( ,individual ,cass9i's ,division #b1bjj #cd1hjj #cg1jjj ,moonlets1 probably ,out] ,r+ #aa1jjj #cg1jjj #dh1jjj less ?an ?ree miles 9 diamet]4 ,,table ,,iii ,,! ,,tw5ty ,,brighte/ ,,/>s ,,9 ,,! ,,heav5s ,passes ,on ?r\gh ,di/ance ,"n ,magnitude ,color ,m]idian ! ,z5i? 9 #i ,p4 ,m4 9 ,latitude,light-,ye>s ---------------------------------------- ---------------------------------------- ----- ,sirius1 ,alpha ,canis ,majoris -#a4f ,:ite ,febru>y #ab #ag ,s4 #h4h ,canopus1#c ,alpha ,argus -#j4i ,:ite ,febru>y #h #ec ,s4 8 ,alpha ,c5tauri#c #j4a ,yell[ ,june #ae #fa ,s4 #d4c ,vega1 ,alpha ,lyr #j4a ,:ite ,augu/ #ae #ci ,n4 #dj ,capella1 ,alpha ,aurig #j4b ,yell[ ,janu>y #bj #df ,n4 #ch ,arcturus1 ,alpha ,botis #j4b ,orange ,june #aj #bj ,n4 #ba ,rigel1 ,beta ,orionis #j4h ,blui%-,:ite,janu>y #bj #h ,s4 8 ,procyon1 ,alpha ,canis ,m9oris #j4e ,:ite ,febru>y #bf #e ,n4 #ab ,a*]n>1#c ,alpha ,eridani #j4f ,blui%-,:ite,decemb] #b #eh ,s4 #hj ,beta ,c5tauri #j4i ,blui%-,:ite,june #g #fj ,s4 #ajj ,betelgeuze1 ,alpha ,orionis ,v>4 ,r$ ,janu>y #ca #g ,n4 #aej-bgj8 #a4j-a4d ,altair1 ,alpha ,aquil #j4i ,:ite ,septemb] #d #i ,n4 #af ,alpha ,crucis#c 7,d\ble ,/>7 #a4f-b4a ,blui%-,:ite,may #ad #fc ,s4 #bbj ,aldeb>an1 ,alpha ,tauri #a4a ,r$ ,janu>y #aa #af ,n4 #bg ,pollux1 ,beta ,gem9orum #a4b ,yell[ ,febru>y #bh #bh ,n4 #ce ,spica1 ,alpha ,virg9is #a4b ,blui%-,:ite,may #bi #aa ,s4 8 ,ant>es1 ,alpha ,scorpii #a4b ,r$ ,july #ab #bf ,s4 #hej ,fomalhaut1 ,alpha ,piscis #a4c ,:ite ,octob] #bd #cj ,s4 #be ,au/ralis ,d5eb1 ,alpha ,cygni #a4c ,:ite ,septemb] #ai #de ,n4 8 ,regulus1 ,alpha ,leonis #a4c ,:ite ,april #h #ab ,n4 #cb ,,footnote3 #c ,invisible nor? ( #ce ,n4 ,lat4 7approximate74 ,,table ,,iv ,a ,,li/ ,,( ,,! ,,pr9cipal ,,con/ellations #a4 ,,visible ,,9 #dj ,,nor? ,,latitude ,passes ,"n ,*ief ,/> ,on ,m]idian ,ov]head or #i ,p4 ,m4 9 ,latitude#d ,not$ ,object 7,degrees7 ---------------------------------------- -------------------- ,&rom$a ,great ,nebula ,novemb] #ce ,n4 ,aqu>ius ,octob] #e ,s4 ,aquila ,altair ,septemb] #j ,aries ,decemb] #bj ,n4 ,auriga ,capella ,febru>y #dj ,n4 ,botes ,arcturus ,june #cj ,n4 ,canc] ,praesepe ,m>* #bj ,n4 ,canes ,v5atici ,cor ,c>oli ,june #dj ,n4 ,canis ,major ,sirius ,m>* #bj ,s4 ,canis ,m9or ,procyon ,m>* #aj ,n4 ,capricornus ,octob] #ae ,s4 ,cassiopeia ,novemb] #fj ,n4 ,cepheus ,novemb] #gj ,n4 ,cetus ,mira ,decemb] #e ,s4 ,columba ,febru>y #ce ,s4 ,coma ,b]5ices ,may #be ,n4 ,corona ,borealis ,alphecca ,july #cj ,n4 ,corvus ,may #bj ,s4 ,crat] ,may #ae ,s4 ,cygnus4 ,d5eb ,septemb] #dj ,n4 ,delph9us ,mo/ di/ant ,septemb] #ae ,n4 globul> clu/] ,draco ,alpha ,augu/ #fe ,n4 ,eridanus ,a*]n> ,janu>y #aj ,n4 to #fj ,s4 ,gem9i ,pollux ,m>* #be ,n4 ,h]cules ,great ,clu/] ,july #cj ,n4 ,hydra ,april #bj ,s4 ,leo ,regulus ,april #ae ,n4 ,lepus ,febru>y #bj ,s4 ,libra ,june #ae ,s4 ,lynx ,april #de ,n4 ,lyra ,vega ,augu/ #dj ,n4 ,ophiu*us ,july #aj ,s4 ,orion ,great ,nebula ,febru>y #j ,piscis ,au/ralis ,fomalhaut ,octob] #cj ,s4 ,pegasus ,novemb] #bj ,n4 ,p]seus ,algol ,janu>y #ej ,n4 ,pisces ,decemb] #e ,n4 ,sagitta ,septemb] #bj ,n4 ,sagitt>ius ,augu/ #cj ,s4 ,scorpio ,ant>es ,july #cj ,s4 ,s]p5s ,july #bj ,n4 to #ae ,s4 ,taurus ,pleiades ,janu>y #bj ,n4 ,triangulum ,decemb] #ce ,n4 ,ursa ,major ,miz> ,may #fe ,n4 ,ursa ,m9or ,pol>is #he ,n4 ,virgo ,spica ,june #j ,,footnote3 #d ,! approximate position ( ! c5t] ( ! con/ellation4 #b4 ,,invisible ,,9 #dj ,,nor? ,,latitude ,on ,passes ,"n ,*ief ,/> ,m]idian ,ov]head or #i ,p4 ,m4 9 ,latitude#d ,not$ ,object 7,degrees7 ---------------------------------------- ----------- ,apus ,july #ge ,s4 ,ara ,july #ee ,s4 ,argo ,navis ,canopus ,m>* #ej ,s4 #a4 ,c>9a ,m>* #fj ,s4 #b4 ,puppis ,m>* #de ,s4 #c4 ,vela ,m>* #ej ,s4 ,c5taurus ,alpha ,c5tauri ,june #ej ,s4 ,crux 7,s\!rn ,cross7 ,alpha ,crucis ,june #fj ,s4 ,dorado ,gt4 ,magellanic ,cl\d ,febru>y #eh ,s4 ,grus ,octob] #de ,s4 ,hydrus ,less] ,mag4 ,cl\d #gj ,s4 ,indus ,septemb] #ee ,s4 ,lupus ,june #dj ,s4 ,musca ,june #gj ,s4 ,octans #he ,s4 ,pavo ,octob] #fe ,s4 ,pho5ix ,novemb] #de ,s4 ,telescopium ,july #dh ,s4 ,triangulum ,au/rale ,july #fe ,s4 ,tucana ,great ,clu/] ,novemb] #fj ,s4 ,volans ,m>* #ge ,s4 ,,table ,v ,,pronunciations ,,& ,,mean+s ,,( ,,names ,,( ,,/>s ,,& ,,con/ellations #a4 ,,/>s ,"n ,pronunciation ,mean+ ---------------------------------------- ------------- ,a*]n> a-ker-nr ,end-(-!-,riv] ,aldeb>an al-deb-ar-an ,! ,h9dmo/ ,altair al-tar ,ant>es an-ta-rez ,rival ( ,ares 7,m>s7 ,arcturus rk-tu-rus ,bellatrix bel-latrix ,! ,female ,w>rior ,betelgeuze bet-el-g]z or bet-el-gez ,! ,arm-,pit ,canopus cn-o-pus ,capella ca-pel-la ,little ,%e-,goat ,d5eb den-eb ,d5ebola de-neb-o-la ,! ,lion's ,tail ,fomalhaut fo-mal-o ,! ,fi%'s ,m\? ,hyades hi-a-dez ,! ,ra9y ,ones ,pleiades ple-ad-ez ,pollux pol-lux ,praesepe pre-se-pe ,! ,beehive ,procyon pro-si-on ,precursor ( ! ,dog ,regulus reg-u-lus ,! ,rul] ,rigel ri-gel or ri-jel ,sirius sir-i-u ,! ,sp>kl+ ,"o ,spica spi-ka ,! ,e> ( ,:eat ,vega ve-ga #b4 ,,con/ellations ,"n ,pronunciation ,mean+ ---------------------------------------- ----------------- ,&rom$a an-drom-e-da ,! ,woman ,*a9$ ,aqu>ius a-kwa-ri-u ,! ,wat]-be>] ,aquila ak-wi-la ,! ,eagle ,ara a-ra ,! ,alt> ,argo ,navis r-g-na-vis ,! ,%ip ,argo ,aries a-res ,! ,ram ,auriga w-ri-ga ,! ,*>iote] ,botes bo-o-tez ,! ,h]dsman ,canc] can-s] ,! ,crab ,canes ,v5atici ca-nez v5-at-i-si ,! ,hunt+ ,dogs ,canis ,major ca-nis major ,! ,great] ,dog ,canis ,m9or ca-nis minor ,! ,less] ,dog ,capricornus cap-ri-kr-nus ,! ,goat ,cassiopeia cas-si-o-pe-ya ,c5taurus c5-tw-rus ,! ,c5taur ,cepheus se-fe-u ,cetus se-tus ,! ,:ale ,columba col-um-ba ,! ,dove ,coma ,b]5ices coma b]-e-ni-ses ,b]5ice's ,hair ,corona ,borealis co-ro-na bo-re-a-lis ,! ,nor!rn ,cr[n ,corvus cr-vus ,! ,cr[ ,crat] cra-t] ,! ,cup ,crux krux ,! ,cross ,cygnus sig-nus ,! ,swan ,delph9us del-fi-nus ,! ,dolph9 ,dorado dr-a-d ,! ,goldfi% ,draco dra-co ,! ,dragon ,eridanus e-rid-a-nus ,! ,riv] ,eridanus ,gem9i jem-i-ni ,! ,tw9s ,grus grus ,! ,crane ,h]cules h]-ku-lez ,hydra hi-dra ,! ,wat]-snake ,hydrus hi-drus ,! ,s]p5t ,indus ind-u ,! ,indian ,leo le-o ,! ,lion ,lepus le-pus ,! ,h>e ,libra li-bra ,! ,scales ,lupus lu-pus ,! ,wolf ,lynx ,! ,fox ,lyra li-ra ,! ,lyre ,musca mus-ca ,! ,fly ,octans oct-ans ,! ,octant ,ophiu*us o-fi-u-kus ,! ,s]p5t-hold] ,orion o-ri-on ,! ,w>rior ,pavo p-vo ,! ,peacock ,pho5ix fe-nix ,piscis ,au/ralis pis-sis aus-tra-lis ,! ,s\!rn ,fi% ,pegasus peg-a-sus ,! ,w+$ ,horse ,p]seus per-se-u or p]-sus ,pisces pis-sez ,! ,fi%es ,sagitta sa-jit-ta ,! ,arr[ ,sagitt>ius sa-jit-ta-ri-u ,! ,ar*] ,scorpio skr-pi-o ,! ,scorpion ,s]p5s s]-p5s ,! ,s]p5t ,taurus tu-rus ,! ,bull ,telescopium tel-es-cop-i-um ,! ,telescope ,triangulum tri-an-gu-lum ,! ,triangle ,tucana tuc-an-a ,! ,t\can ,ursa ,major ur-sa ma-jor ,! ,great] ,be> ,ursa ,m9or ur-sa mi-nor ,! ,less] ,be> ,virgo ver-g ,! ,maid5 ,volans vol-ans ,! ,fly+ ,fi% 99 99 99 99 99 ,transcrib]'s ,note3 ,obvi\s typographical errors h be5 repair$4 ,und]scores surr\nd italiciz$ cont5t4 ,mid-p>agraph illu/rations 7 mov$ ne> to ! text describ+ ! illu/rat$ mat]ial4 ,r$undant title--,a/ronomy = ,"y ,folks--on p4 #c 0 delet$4 ,p4 #c3 ,can/ ?\ br+ =? ,mazz>o?--,can/ is assum$ 9 blank space4 ,p4 #be3 bright] object ?an ! ne>by /> ,aldeb>an--/> is assum$ 9 blank space4 ,p4 #abb3 ,illu/ration orig9ally /at$ ,see note page #abf4 ,t /atem5t 0 remov$1 & ! actual note f page #abf 0 mov$ to its place ) ! illu/ration4 ,p4 #agd3 444--duplicate ( lat] l9e occurr$ at ,l',aigle1 ,france1 9 #ahjc4 ,betwe5 two appe>$ at ?is spot4 ,possible miss+ text :]e ! l9e occurr$4 p4 #bcc3 p]iod ( #b;d #bj;h #dh4im--c>at 77 indicates t ! lett] imm$iately foll[+ appe>s z a sup]script4 ,data 9 tables reta9$ z 9 orig9al1 b may be incorrect--= example1 ! escape velocity ( ,m>s1 repres5t$ z #a4e miles p] second 9 ,table ,i1 is clos] to #c4a4