,,! ,,/ory ,,( ,,! ,,sol> ,,sy/em ,,by ,,george ,f4 ,,*amb]s1 ,f4,r4,a4,s4 ,,( ,,! ,,inn] ,,temple1 ,,b>ri/]-,,at-,,law ,,au?or ,,( ,,! ,,/ory ,,( ,,! ,,/>s ,illu/ration3 ,,) ,,tw5ty-,,eight ,,illu/rations ,,new ,,york ,mc,c,l,u,r,e1 ,,phillips ,,co4 ,,mcmiv ,copyright1 #ahie1 ,by ,d4 ,,appleton ,,& ,,company4 ,illu/ration3 ,fig4 #a4--,! ,planet ,saturn4 ,,preface4 ,hav+ 9 my 8,/ory ( ! ,/>s0 told ( f> di/ant suns1 _m ( !m probably ) planets revolv+ ar\nd !m1 ,i h 9 ! pres5t volume1 :i* is a companion to ! =m] "o1 to treat ( ! ,sun 9 p>ticul>--our ,sun z we may call him--& ! body ( att5dants :i* own 8 sway by revolv+ r\nd him4 ,! att5dants are ! planets1 commonly s call$1 toge!r ) a c]ta9 numb] ( comets4 ,i %all deal ) all ^! objects r f a descriptive & practical ?an f a speculative or essay po9t ( view1 & ) special ref]5ce to ! conv5i5ce & opportunities ( p]sons possess+1 or hav+ access to1 :at may be call$ popul> telescopes--telescopes say ( f two to f\r in*es ( ap]ture1 & co/+ any sum betwe5 #aj & #ej4 ,!re is mu* pleasure & pr(it to be got out ( telescopes ( ?is type1 always presum+ t !y are us$ by p]sons possess$ ( pati5ce & p]sev]ance4 ,x is a v great mi/ake1 ?\gh an extremely common "o1 to suppose t unless a man c comm& a big telescope he c d no useful "w1 & d]ive no pleasure f 8 "w4 ,to all su* croak]s ,i always po9t z a moral ! a*ievem5ts ( ,h]mann ,golds*midt1 :o f an attic w9d[ at ,font5ay-aux-,roses ne> ,p>is1 ) a telescope ( only #b in*es ap]ture1 discov]$ no few] ?an #ad m9or planets4 ,z ?is volume is int5d$ = g5]al read+1 r ?an = educational or te*nical purposes1 ,i h kept /ati/ical details & num]ical expressions )9 v n>r[ limits1 m]e figures be+ always m or less unattractive4 ,john ,ri*>d ,gre51 9 ! ,preface to 8 book on ,! ,mak+ ( ,engl&1 writes z foll[s3--8,i may add1 9 explanation ( ! reappe>ance ( a few passages 444 :i* my read]s may h se5 be=e1 t :]e ,i _h little or no?+ to add or to *ange1 ,i h pref]r$ to ins]t a passage f previ\s "w1 ) ! requisite connections & ref]5ces1 to ! affectation ( rewrit+ su* a passage = ! m]e sake ( giv+ x an air ( novelty40 ,i w v5ture to adopt ?is ?\ght z my own1 & to apply x to ! repetition1 "h & !re1 ( ideas & phrases :i* are already to be f\nd 9 my ,h&book ( ,a/ronomy4 ,g4 ,f4 ,c4 ,nor?field ,grange1 ,ea/b\rne1 #ahie4 ,,cont5ts4 ,,*apt] ,,page ,i4 ,introductory ,/atem5t #g ,,ii4 ,! ,sun #ah ,,iii4 ,m]cury #eg ,,iv4 ,v5us #fa ,v4 ,! ,e>? #fi ,,vi4 ,! ,moon #hi ,,vii4 ,m>s #ajj ,,viii4 ,! ,m9or ,planets #aaj ,,ix4 ,jupit] #aae ,x4 ,saturn #abb ,,xi4 ,uranus #ach ,,xii4 ,neptune #adc ,,xiii4 ,comets #aej ,app5dix--,tables ( ! ,sol> ,sy/em #ahb ,g5]al ,index #ahe ,,li/ ,,( ,,illu/rations4 ,,figure ,,page #a4 ,! ,planet ,saturn ,frontispiece #b4 ,incl9ation ( ,planet>y ,orbits #i #c4 ,comp>ative ,sizes ( ,major ,planets #aa #d4 ,comp>ative ,size ( ! ,sun z se5 f ! ,planets ,nam$ #ag #e4 ,ord9>y ,sun-spots1 ,june #bb1 #ahhe #bb #f4 ,*ange ( ,=m 9 ,sun-spots ,ow+ to ! ,sun's ,rotation #bi #g4 ,sun-spots se5 z a ,not* #cg #h4 ,! ,sun ,totally ,eclips$1 ,july #ah1 #ahfj #ef #i4 ,v5us1 ,dec4 #bc1 #ahhe #fd #aj4 ,v5us ,ne> ,conjunction z a ,?9 ,cresc5t #fe #aa4 ,m>e ,crisium 7,lick ,obs]vatory photographs7 #ij #ab4 ,f\r ,views ( ,m>s 7,b>n>d7 #aja #ac4 ,m>s1 ,aug4 #bg1 #ahib 7,guyot7 #ajg #ad4 ,jupit]1 ,nov4 #bg1 #aheg 7,dawes7 #aaf #ae4 ,saturn1 #ahhi #abc #af4 ,g5]al ,view ( ! ,phases ( ,saturn's ,r+s #abf #ag4 ,phases ( ,saturn's ,r+s at ,specifi$ ,dates #abi #ah4 ,saturn ) ,titan & its ,%ad[ #acg #ai4 ,telescopic ,comet ) a ,nucleus #aed #bj4 ,comet se5 9 ,daylight1 ,sept41 #ahhb #aee #ba4 ,qu5isset's ,comet1 ,july #i1 #ahic #aef #bb4 ,holmes's ,comet1 ! ,head on ,nov4 #i1 #ahib 7,d5n+7 #aei #bc4 ,holmes's ,comet1 ! ,head on ,nov4 #af1 #ahib 7,d5n+7 #aei #bd4 ,comet ,,iii4 ( #ahfb1 on ,aug4 #bb1 %[+ ,jet ( ,lum9\s ,matt] 7,*allis7 #afj #be4 ,saw]?al's ,comet1 ,june #d1 #ahhh 7,*>lois7 #afe #bf4 ,biela's ,comet1 #ahdf #afi #bg4 ,! ,great ,comet ( #ahaa #agg #bh4 ,! ,great ,comet ( #ahhb #agi ,,! ,,/ory ,,( ,,! ,,sol> ,,sy/em4 ,,*apt] ,i4 ,,introductory ,,/atem5t4 ,by ! t]m 8,sol> ,sy/em0 x is to be und]/ood t an ,a/ronom]1 speak+ f ! /&po9t ( an inhabitant ( ! ,e>?1 wi%es to ref] to t object1 ! ,sun1 :i* is to him ! mat]ial & visible c5tre ( life & heat & control1 & also to ^? bodies dep5d5t on ! ,sun :i* circulate r\nd x at v>i\s di/ances1 d]iv+ _! light & heat f ! ,sun1 & kn[n z planets & comets4 ,! /atem5t j made may be reg>d$ z a g5]al tru?1 b z ! /ricte/ accuracy on sci5tific matt]s is ( ! utmo/ importance1 a trivial res]vation mu/ p]haps be put ^u ! =ego+ broad ass]tion4 ,!re is "s reason = ?9k+ t possibly "o ( ! planets 7,jupit]7 possesses a little inh]5t light ( its own :i* is n borr[$ f ! ,sun2 :il/ ( ! comets x mu/ c]ta9ly be said t1 z a rule1 !y %9e ) intr9sic1 n borr[$ light4 ,respect+ ^! res]vations m h]eaft]4 ,! planets are divid$ into 8prim>y0 & 8second>y40 ,by a 8prim>y0 planet we mean "o :i* directly circulates r\nd ! ,sun2 by a 8second>y0 planet we mean "o :i* 9 ! fir/ in/ance circulates r\nd a prim>y planet1 & !re=e only 9 a second>y s5se circulates r\nd ! ,sun4 ,! planets are also 8major0 or 8m9or02 ?is1 h[ev]1 is only a di/9ction ( size4 ,! second>y planets are usually t]m$ 8satellites10 or1 v (t51 9 popul> language1 8moons10 because !y own allegiance to _! respective prim>ies j z our ,moon--! ,moon--does to ! ,e>?4 ,b ! use ( ! t]m 8moon0 is inconv5i5t1 & x is bett] to /ick to 8satellite40 ,!re is yet ano!r me?od ( classify+ ! planets :i* has its advantages4 ,!y are sometimes divid$ into 8inf]ior0 & 8sup]ior40 ,! 8inf]ior0 planets are ^? :i* travel r\nd ! ,sun 9 orbits :i* are inside ! ,e>?'s orbit2 ! 8sup]ior0 planets are ^? ^: orbits are outside ! ,e>?4 ,! foll[+ is an enum]ation ( ! major planets 9 ! ord] ( _! di/ances1 reckon+ f ! ,sun outw>ds3-- #a4 ,m]cury4 #b4 ,v5us4 #c4 ,! ,e>?4 #d4 ,m>s4 #e4 ,jupit]4 #f4 ,saturn4 #g4 ,uranus4 #h4 ,neptune4 ,all ! above are major planets & also prim>y planets4 ,9 betwe5 ,nos4 #d & #e circulate ! 8,m9or0 planets1 an ev]-increas+ body1 n[ m ?an #djj 9 numb]1 b all1 except "o or p]haps two1 invisible to ! nak$ eye4 ,! 8,inf]ior0 planets x w be se5 f ! above table comprise ,m]cury & ,v5us1 :il/ ! 8,sup]ior0 planets are ,m>s & all ^? beyond4 ,great diff]5ces exi/ 9 ! incl9ations ( ! orbits ( ! diff]5t planets to ! plane ( ! ecliptic1 a fact :i* is bett] %[n by a diagram ?an by a table ( m]e figures4 ,! orbit ( ,uranus is inde$ s mu* incl9$ t its motion is really retrograde comp>$ ) ! g5]al run ( ! planets3 & ! same rem>k applies1 ?\gh mu* m =cibly1 to ! case ( ,neptune4 ,illu/ration3 ,fig4 #b4--;,incl9ation ( ,planet>y ,orbits4 ,! actual movem5ts ( ! planets r\nd ! ,sun are extremely simple1 = !y d n\ght else b g on1 & on1 & on1 incessantly1 always 9 ! same direction1 & almo/1 ?\gh n q1 at a uni=m pace1 ?\gh 9 orbits v v>i\sly incl9$ to ! plane ( ! ecliptic4 ,b an elem5t ( extreme complication is introduc$ into _! app>5t movem5ts by reason ( ! fact t we are oblig$ to /udy ! planets f "o ( _! own numb]1 :i* is itself always 9 motion4 ,if ! ,e>? itself 7 a fixture1 ! /udy ( ! movem5ts ( ! planets w\ld be a comp>atively easy matt]1 :il/ to an obs]v] on ! ,sun x w\ld be a supremely easy matt]4 ,greatly z ! planets diff] among !mselves 9 _! sizes1 di/ances f ! ,sun1 & physical peculi>ities1 !y h c]ta9 ?+s 9 common1 & x w be well to make ?is matt] cle> be=e we g into m recondite topics4 ,= in/ance1 n only d !y move incessantly r\nd ! ,sun 9 ! same direction at a ne>ly uni=m pace1 b ! planes ( _! orbits are v little incl9$ to ! common plane ( ref]5ce1 ! ecliptic1 or to "o ano!r4#a ,! direction ( motion ( ! planets z view$ f ! nor? side ( ! ecliptic is contr>y to ! motion ( ! h&s ( a wat*4 ,_! orbits1 unlike ! orbits ( comets1 are ne>ly circul>1 t is1 !y are only v slightly oval4 ,agreeably to ! pr9ciples ( :at is kn[n z ! ,law ( ,univ]sal ,gravitation1 ! spe$ ) :i* !y move 9 _! orbits is greate/ 9 ^? p>ts :i* lie ne>e/ ! ,sun1 & lea/ 9 ^? p>ts :i* are mo/ remote f ! ,sun2 9 o!r words1 !y move quicke/ 9 ,p]ihelion & sl[e/ 9 ,aphelion4 ,illu/ration3 ,fig4 #c4--;,comp>ative ,sizes ( ! ,major ,planets4 ,! physical peculi>ities :i* ! planets h 9 common include ! foll[+ po9ts3--!y are opaque bodies1 & %9e by reflect+ light :i* !y receive f ! ,sun4 ,probably all ( !m are endu$ ) an axial rotation1 h5ce _! inhabitants1 if !re are any1 h ! alt]nation ( day & night1 l ! inhabitants ( ! ,e>?1 b ! duration ( _! days1 measur$ 9 absolute t]re/rial h\rs1 w 9 mo/ cases diff] mat]ially f ! days & nights ) :i* we are famili>4 ,i /at$ on a previ\s page t1 ow+ to ! circum/ances 9 :i* we f9d ourselves on ! ,e>?1 ! app>5t & real movem5ts ( ! planets are widely diff]5t4 ,x w\ld be beyond ! scope ( ?is little "w to g into ^! diff]5ces 9 any consid]able detail2 suffice x !n to indicate only a few g5]al po9ts4 ,9 ! fir/ place1 an important di/9ction exi/s betwe5 ! visible movem5ts ( ! inf]ior & sup]ior planets4 ,! inf]ior planets1 ,m]cury & ,v5us1 ly+ z !y d )9 ! orbit ( ! ,e>?1 are mu* re/rict$ 9 _! movem5ts1 9 ! sky4 ,we c nev] see !m except :5 !y are m or less ne> to ! ris+ 7or ris57 or sett+ 7or set7 ,sun4 ,! extreme angul> di/ance f ! ,sun 9 ! sky to :i* ,m]cury c atta9 is b #bg1 & !re=e we c nev] obs]ve x o!rwise ?an 9 sunlight or twilight1 = x nev] rises m ?an #a h\rs be=e sunrise nor sets lat] ?an #a h\rs aft] sunset4 ,( c\rse betwe5 ^! limits ! planet is above ! horizon all ! "t t ! ,sun is above ! horizon1 b except 9 v l>ge telescopes is n usually to be detect$ dur+ ! day-"t4 ,^! rem>ks reg>d+ ,m]cury apply likewise 9 pr9ciple to ,v5us2 only ! orbit ( ,v5us be+ l>g] ?an ! orbit ( ,m]cury1 & ,v5us itself be+ l>g] 9 size ?an ,m]cury1 ! application ( ^! pr9ciples leads to some:at diff]5t results4 ,! greate/ possible di/ance ( ,v5us may be #dg in/ead ( ,m]cury's #bg4 ,v5us is !re=e some:at m emancipat$ f ! effects ( twilight4 ,! body ( ,v5us be+ also v mu* l>g] & bright] ?an ! body ( ,m]cury1 x may be m (t5 & m easily detect$ 9 broad daylight4 ,x foll[s f ! =ego+ /atem5t t ! inf]ior planets c nev] be se5 9 ^? regions ( ! heav5s :i* are1 z x is te*nically call$1 9 8,opposition0 to ! ,sun2 t is1 :i* are on ! m]idian at midnight :il/ ! ,sun is on ! m]idian 9 its midday spl5d\r to places on ! opposite side ( ! ,e>?4 ,on ! o!r h&1 ! two inf]ior planets on /at$1 ?\gh r>e1 occasions exhibit to a t]re/rial spectator c]ta9 ph5om5a ( great int]e/ & importance 9 :i* no sup]ior planet c ev] take "p4 ,i am "h ref]r+ to ! 8,transits0 ( ,m]cury & ,v5us across ! ,sun4 ,if ^! planets & ! ,e>? all revolv$ r\nd ! ,sun exactly 9 ! plane ( ! ecliptic1 transits ( ^! planets w\ld be p]petually recurr+ aft] ev5 int]vals ( only a few mon?s2 b ! fact t ! orbit ( ,m]cury is incl9$ #g1 & t ( ,v5us ab\t #c1 to ! ecliptic1 involves su* complications t transits ( ,m]cury only occur at unequal int]vals ( sev]al ye>s1 :il/1 9 extreme cases1 m ?an a c5tury may elapse betwe5 two successive transits ( ,v5us4 ,= a transit ( an inf]ior planet ov] ! ,sun to take place1 ! ,e>? & ! planet & ! ,sun mu/ be exactly 9 ! same /raight l9e1 reckon$ bo? v]tically & horizontally4 ,twice 9 e revolution r\nd ! ,sun an inf]ior planet is v]tically 9 ! same /raight l9e ) ! ,e>? & ! ,sun2 & x is said to be 9 8inf]ior conjunction0 :5 ! planet comes betwe5 ! ,e>? & ! ,sun2 & 9 8sup]ior conjunction0 :5 ! planet is on ! fur!r side ( ! ,sun1 ! ,sun int]v5+ betwe5 ! ,e>? & ! planet4 ,b = all ?ree to be horizontally 9 ! same /raight l9e is q ano!r matt]4 ,x is ! orbital incl9ations ( ,m]cury & ,v5us :i* enable !m1 s to speak1 to dodge an obs]v] :o is on ! look\t to see !m pass exactly 9 front ( ! ,sun1 or to disappe> beh9d ! ,sun2 & s x comes ab\t t a fav\rable comb9ation ( circum/ances :i* is r>e is ne$$ be=e ei!r ( ! a=esaid planets c be se5 z r\nd black spots pass+ 9 front ( ! ,sun4 ,a passage ( ei!r ( ^! planets beh9d ! ,sun c\ld nev] be se5 by human eye1 because ( ! ov]p[]+ brilliancy ( ! ,sun's rays1 ev5 ?\gh an ,a/ronom] might "k by 8 calculations ! exact mom5t t ! planet 0 go+ to pass beh9d ! ,sun4 ,:5 an inf]ior planet atta9s its greate/ angul> di/ance f ! ,sun1 z we see x 7:i* ,i h already /at$ to be ab\t #bg 9 ! case ( ,m]cury & #dg 9 ! case ( ,v5us71 su* planet is said to be at its 8greate/ elongation10 8ea/0 or 8we/10 z ! case may be4 ,at ea/]n elongation or inde$ :5ev] ! planet is ea/ ( ! ,sun1 x is1 to use a famili> phrase1 an 8ev5+ />02 on ! o!r h&1 at we/]n elongation1 or :5ev] x is on ! we/]n side ( ! ,sun1 x is kn[n z a 8morn+ />40 ,if ! movem5ts ( an inf]ior planet are foll[$ suffici5tly long by ! aid ( a /> map1 x w be se5 t sometimes x appe>s to be proce$+ 9 a =w>d direction ?r\gh ! signs ( ! zodiac2 !n = a :ile x w seem to /& /ill2 !n at ano!r "t x w app>5tly g backw>ds1 or possess a retrograde motion4 ,all ^! peculi>ities h _! orig9at+ cause 9 ! motion ( ! ,e>? itself1 = ! absolute movem5t ( ! planet nev] v>ies1 be+ always 9 ! same direction1 t is1 =w>ds 9 ! ord] ( ! signs4 ,turn+ n[ to ! sup]ior planets1 we h to face an altoge!r diff]5t succession ( circum/ances4 ,a sup]ior planet is n1 z x 71 *a9$ to ! ,sun s z to be unable to escape beyond ! limits ( morn+ or ev5+ twilight2 x may h any angul> di/ance f ! ,sun up to #ahj1 rea*+ :i* po9t x approa*es ! ,sun on ! opposite side1 /ep by /ep1 until x aga9 comes into conjunction ) ! ,sun4 ,z appli$ to a sup]ior planet1 ! t]m 8conjunction0 means ! absolute mom5t :5 ! ,e>? & ! ,sun & ! planet are 9 ! same /raight l9e1 ! ,sun be+ 9 ! middle4 ,9 su* a case1 to u on ! ,e>? ! planet is lo/ 9 ! ,sun's rays1 :il/ to a spectator on ! planet ! ,e>? w\ld appe> simil>ly lo/ 9 ! ,sun's rays1 z ! ,e>? w\ld be at t /age ( h] orbit :i* we1 speak+ ( our inf]ior planets1 call sup]ior conjunction4 ,= a cle> compreh5sion ( all ! v>i\s matt]s :i* we h j be5 speak+ (1 a c>eful /udy ( diagrams ( a geometrical "*1 or bett] /ill1 ( models1 w\ld be necess>y4 ,some?+ mu/ n[ be said ab\t ! phases ( ! planets4 ,m]cury & ,v5us1 9 reg>d to _! orbital motions1 /& v mu* on ! same foot+ ) respect to ! inhabitants ( ! ,e>? z ! ,moon does1 & accord+ly bo? ^? planets 9 _! p]iodical circuits r\nd ! ,sun exhibit ! same succession ( phases z ! ,moon does4 ,9 ! case1 h[ev]1 ( ! sup]ior planets ?+s are o!rwise4 ,two only ( !m1 ,m>s & ,jupit]1 are suffici5tly ne> ! ,e>? to exhibit any phase at all4 ,:5 !y are 9 quadrature 7i4 e41 #ij f ! ,sun on ei!r side7 !re is a slight loss ( light to be notic$ along "o limb4 ,9 o!r words1 ! disc ( ea* ceases = a %ort "t1 & to a slight ext5t1 to be truly circul>2 x becomes :at is kn[n z 8gibb\s40 ,?is occasional feature ( ,m>s may be fairly conspicu\s1 or1 at lea/1 noticeable2 b 9 ! case ( ,jupit] x w be less obvi\s unless a telescope ( "s size is employ$4 ,if ! major planets are arbitr>ily rang$ 9 two gr\ps1 ,m]cury1 ,v5us1 ! ,e>? & ,m>s be+ tak5 z an int]ior gr\p1 comp>atively ne> ! ,sun2 :il/ ,jupit]1 ,saturn1 ,uranus & ,neptune are reg>d$ z an ext]ior gr\p1 be+ at a great di/ance f ! ,sun1 x w be f\nd t "s important physical diff]5ces exi/ betwe5 ! two gr\ps4 ,illu/ration3 ,fig4 #d4--;,comp>ative size ( ! ,sun z se5 f ! ,planets nam$4 ,( ! int]ior planets1 ! ,e>? & ,m>s alone h satellites1 & betwe5 !m make up a total ( only ?ree4 ,! ext]ior planets1 on ! o!r h&1 all h satellites1 ! total numb] be+ c]ta9ly sev5te51 & possibly eighte54 ,9 detail1 ,jupit] has f\r1 ,saturn eight1 ,uranus f\r1 & ,neptune "o1 & p]haps two4 ,^! facts may be reg>d$ z an in/ance ( ! b5efic5ce ( ! ,creator ( ! ,univ]se if we consid] t ! satellites ( ^! remot] planets are s num]\s1 9 ord] t by _! numb]s !y may d some?+ to make up = ! small am\nt ( light :i*1 ow+ to _! di/ance f ! ,sun1 _! prim>ies receive4 ,!n aga91 ! av]age d5sity ( ! fir/ gr\p ( planets greatly exce$s ! av]age d5sity ( ! second gr\p 9 ! approximate ratio ( #e to #a4 ,f9ally1 !re is reason to believe t a m>k$ diff]5ce exi/s 9 ! axial rotations ( ! planets =m+ ! two gr\ps4 ,we d n "k ! precise figures = all ! ext]ior planets1 b ! k :i* we d possess seems to imply t ! av]age l5g? ( ! day 9 ! case ( ! int]ior planets is ab\t tw5ty-f\r h\rs1 b t 9 ! case ( ! ext]ior planets x is no m ?an ab\t t5 h\rs4 ,^! figures c1 h[ev]1 only be pres5t$ z possibly true1 because obs]vations on ! rotation p]iods ( ,m]cury & ,v5us on ! "o h&1 & ( ,uranus & ,neptune on ! o!r1 are att5d$ ) s mu* difficulty t ! record$ results are ( d\btful tru/wor?9ess4 ,x is1 h[ev]1 reasonable to presume t ! actual size ( ! respective planets has m to d ) ! matt] ?an _! di/ances f ! ,sun4 ,i ?9k t ! =ego+ summ>y respect+ ! planets collectively embraces z _m po9ts z are likely to be ( int]e/ to ! g5]ality ( read]s2 we w !re=e pass on to consid] some:at 9 detail ! sev]al con/itu5t memb]s ( ! sol> sy/em1 beg9n+ ) ! ,sun4 ,,*apt] ,,ii4 ,,! ,,sun4 ,!re 0 once a book publi%$1 ! title ( :i* 0 8,! ,sun1 ,rul]1 ,fire1 ,light & ,life ( ! ,planet>y ,sy/em40 ,! title 0 by no means a bad "o1 = )\t d\bt ! ,sun may fairly be said to repres5t practically all ! ideas convey$ by ! designations quot$4 ,!re is c]ta9ly no "o body 9 creation :i* is s emphatically pre-em95t z ! ,sun4 ,:e!r or no !re are />s :i* are suns--c5tres ( sy/ems s]v+ 9 _! degree ! purposes s]v$ by our ,sun1 ,i ne$ n n[ pause to enquire1 ?\gh ,i ?9k ! idea is a v probable "o2 b ( ^? cele/ial objects ) :i* our ,e>? has a direct relation%ip1 beyond d\bt ! ,sun is unque/ionably entitl$ to ! =emo/ place4 ,x is1 z x 71 ! pivot on :i* ! ,e>? & all ! v>i\s bodies compris+ ! ,sol> ,sy/em revolve 9 _! annual progress4 ,x is our s\rce ( light & heat1 & !re=e may be call$ ! great ag5t by :i* an ,almighty ,provid5ce wills to su/a9 animal & vegetable life4 ,! consid]ation ( all ! complicat$ que/ions :i* arise out ( ^! functions ( ! ,sun belongs to ! doma9 ( ,physics r ?an t ( ,a/ronomy2 /ill ^! matt]s are ( su* mom5t\s int]e/ t an allusion to !m mu/ be made1 = !y ought n to be lo/ sight ( by ! /ud5t ( ,a/ronomy4 ,half a c5tury ago ! actual /ate ( our k respect+ ! ,sun might )\t difficulty be br\ght )9 ! compass ( a s+le *apt] 9 any book on ,a/ronomy1 b s enorm\s has be5 ! developm5t ( k respect+ ! ,sun ( late ye>s1 t x is no long] a "q ( gett+ ! mat]ials prop]ly into "o *apt]1 b x is a matt] ( a :ole volume be+ devot$ to ! ,sun1 or ev51 z 9 ! case ( ,sec*i1 ( two l>ge octavo volumes ( #ejj pages ea* be+ requir$ to cov] ! :ole gr\nd exhau/ively4 ,! read] w !re=e easily und]/& t 9 ! space at my disposal 9 ?is little "w no?+ b a pass+ glimpse c possibly be obta9$ ( ?is great subject4 ,x is great n only 9 reg>d to ! va/ array ( purely a/ronomical facts :i* are at a writ]'s comm&1 b also on acc\nt ( ! ext5sive ramifications :i* ! subject has into ! doma9s ( *emi/ry1 photography1 optics & cognate sci5ces4 ,i %all !re=e endeav\r to limit myself g5]ally to :at an amateur c see = himself ) a small telescope1 & c readily und]/&1 r ?an attempt to say a little some?+ ab\t ev]y?+1 & fail 9 ! ef=t4 ,! mean di/ance ( ! ,e>? f ! ,sun may be tak5 to be ab\t #ic millions ( miles1 & ?is di/ance is employ$ by ,a/ronom]s z ! unit by :i* mo/ o!r long cele/ial di/ances are reckon$4 ,! true diamet] ( ! ,sun is ab\t #hff1jjj miles4 ,! surface area exce$s t ( ! ,e>? #aa1idf times1 & ! volume is #a1cje1jjj times great]4 ,! mass or weight ( ! ,sun is #ccb1jjj times t ( ! ,e>?1 or ab\t #gjj times t ( all ! planets put toge!r4 ,bulk = bulk ! ,sun is mu* light] ?an ! ,e>?3 :il/ a cubic foot ( ! ,e>? on an av]age weighs r m ?an #e times z mu* z a cubic foot ( wat]1 a cubic foot ( ,sun is only ab\t #c times ! weight ( ! same bulk ( wat]4 ,?is consid]ation ( ! comp>ative lightness ( ! ,sun 7?\gh 9 8 day ! ,sun 0 ?\ght to be light] ?an x is n[ suppos$ to be7 l$ ,sir ,j4 ,h]s*el to inf] t an int5se heat prevails 9 its int]ior1 indep5d5t x may be ( its surface heat1 s to speak1 ( :i* alone we are directly cognizant by ! evid5ce ( our s5ses4 ,! ,sun is a sph]e1 & is surr\nd$ by an ext5sive b att5uat$ envelope1 or r s]ies ( envelopes1 :i* tak5 toge!r be> "s analogy to ! atmosph]e surr\nd+ ! ,e>?4 ,^! envelopes1 :i* we %all h to consid] m 9 detail pres5tly1 ?r[ out rays ( light & heat to ! conf9es ( ! ,sol> ,sy/em1 ?\gh z to ! conditions & circum/ances "u :i* t light & heat are g5]at$ we are entirely ignorant4 ,( ! pot5cy ( ! ,sun's rays we c =m b a feeble conception1 = ! am\nt receiv$ by ! ,e>? is1 x has be5 calculat$1 b "o #bcjj-million? ( ! :ole4 ,our annual %>e w\ld1 x is suppos$1 be suffici5t to melt a lay] ( ice spread uni=mly ov] ! ,e>? to a dep? ( #ajj feet1 or to heat an ocean ( fre% wat] #fj feet deep f freez+ po9t to boil+ po9t4 ,! illum9at+ p[] ( ! ,sun has to be express$ 9 language ( simil> pr(undity4 ,?us x has be5 calculat$ to equal t :i* w\ld be af=d$ by #eefc wax c&les conc5trat$ at a di/ance ( "o foot f ! obs]v]4 ,aga91 x has be5 conclud$ t no few] ?an half a million ( full moons %9+ all at once w\ld be requir$ to make up a mass ( light equal to t ( ! ,sun4 ,i pres5t all ^! conclusions to ! read] z !y are furni%$ by v>i\s physici/s :o h inve/igat$ su* matt]s1 b x is r unc]ta9 z to h[ mu* reliance c safely be plac$ on su* calculations 9 detail4 ,illu/ration3 ,fig4 #e4--,ord9>y ,sun-spot1 ,june #bb1 #ahhe4 ,to an amateur possess$ ( a small telescope1 ! ,sun (f]s 7:5 ! wea!r is above ! ,engli% av]age ( rec5t ye>s7 a v great & con/ant v>iety ( matt]s = /udi\s scrut9y 9 its s-call$ 8spots40 ,to ! nak$ eye1 or ev5 on a ha/y telescopic glance1 ! ,sun pres5ts ! appe>ance ( a uni=m disc ( yell[i% :ite col\r1 ?\gh (t5 a little att5tion w soon result 9 ! discov]y ( a few1 or x may be _m1 little black1 or blacki% pat*es1 scatt]$ "h & !re ov] ! disc seem+ly )\t ord] or me?od4 ,we %all pres5tly f9d out1 h[ev]1 t ?is la/-nam$ sugge/ion is :olly inaccurate4 ,?\gh commonly call$ 8spots10 ^! d>k appe>ances are n simple spots1 z ! ^w might imply1 = ar\nd ! r black pat* :i* con/itutes g5]ally ! ma9 feature ( ! spot !re is almo/ inv>iably a fr+e ( pal] t9t2 :il/ )9 ! conf9es ( ! black pat* :i* fir/ cat*es ! eye !re is (t5 a nucleus or inn] portion ( f> m int5se dep? ( %ade4 ,! inn]mo/ & d>ke/ portion be+ t]m$ ! nucleus1 ! ord9>y black portion is kn[n z umbra1 :il/ ! encompass+ fr+e is ! p5umbra4 ,x is n always ! case t ea* individual umbra has a p5umbra all to itself1 = sev]al spots are occasionally includ$ 9 "o common p5umbra4 ,& x may fur!r be rem>k$ t cases ( an umbra )\t a p5umbra & ! contr>y are on record1 ?\gh ^! may be t]m$ exceptional1 (t5 hav+ relation to mat]ial organic *anges ei!r j comm5c+ or j com+ to a conclusion4 ,a m>k$ contra/ subsi/s 9 all cases betwe5 ! lum9osity ( ! p5umbra & t ( ! g5]al surface ( ! ,sun contigu\s4 ,t[>ds its ext]ior edge ! p5umbra is usually d>k] ?an at its inn] edge1 :]e x comes 9 contact ) ! umbra4 ,! outl9e ( ! p5umbra is usually v irregul>1 b ! umbra1 especially 9 ! l>g] spots1 is (t5 ( regul> =m 7comp>atively speak+ ( c\rse7 & ! nucleus 7or nuclei7 ( ! umbra /ill m noticeably p>takes ( a compactness ( outl9e4 ,spots are = ! mo/ "p conf9$ to a zone ext5d+ #ce or s on ea* side ( ! sol> equator2 & !y are nei!r p]man5t 9 _! =m nor /ation>y 9 _! position4 ,9 _! want ( p]man5ce1 !y are subject1 app>5tly1 to no def9ite laws1 = !y frequ5tly appe> & disappe> ) great sudd5ness4 ,_! motions are evid5tly ( a two-fold nature2 ! ,sun itself rotates on its axis1 & ! spots collectively p>ticipate 9 ?is movem5t ( rotation2 b ov] & above ?is x has be5 conclusively prov$ t sometimes a spot has a prop] motion ( translation ( its own indep5d5tly ( ! motion :i* x has 9 consequ5ce ( ! ,sun's axial rotation4 ,curi\sly en\gh1 spots are v r>e imm$iately "u ! ,sun's equator4 ,x is 9 ! zone ext5d+ f #h to #bj ,nor? or ,s\?1 z ! case may be1 t !y are mo/ abundant2 or1 to be m precise /ill1 _! fav\rite latitude seems to be #ag or #ah4 ,!y are (t5 m num]\s & ( a great] g5]al size 9 ! nor!rn hemisph]e1 to :i* x may be add$ t ! zone betwe5 #aa & #ae ,nor? is p>ticul>ly not$ = l>ge & endur+ spots4 ,a greg>i\s t5d5cy is (t5 v obvi\s1 & :]e ! gr\ps are v /raggl+ an imag9>y l9e jo9+ ! extreme ends ( ! gr\p w g5]ally be f\nd m or less p>allel to ! sol> equator2 & n only s1 b ext5d+ a long way1 or sometimes almo/ entirely1 across ! :ole ( ! visible disc4 ,) respect to ! =ego+ matt]s ,sir ,john ,h]s*el rem>k$3--8,^! circum/ances 444 po9t evid5tly to physical peculi>ities 9 c]ta9 p>ts ( ! ,sun's body m fav\rable ?an 9 o!rs to ! production ( ! spots1 on ! "o h&2 & on ! o!r1 to a g5]al influ5ce ( its rotation on its axis z a det]m9+ cause 9 _! di/ribution & arrangem5t1 & w\ld appe> indicative ( a sy/em ( movem5ts 9 ! fluids :i* con/itute its lum9\s surface2 be>+ no remote analogy to our trade-w9ds--f :atev] cause aris+40 ,m (t5 ?an n :5 a ma9 spot has a tra9 ( m9or spots z foll[]s t tra9 w be f\nd ext5d+ ea/w>ds f ! ea/ side ( ! spot1 r ?an 9 any o!r direction4 ,spots rema9 visible = v div]se l5g?s ( "t1 f ! extreme ( a few m9utes up to a few mon?s2 b a few days up to1 say1 "o mon?1 may1 9 a g5]al way1 be sugge/$ z _! ord9>y limits ( endurance4 ,z ! ,sun rotates on its axis 9 #be days1 & z ! spots may be said to be1 practically speak+1 fix$ or ne>ly s ) respect to ! ,sun's body1 no spot c rema9 cont9u\sly visible = m ?an ab\t #ab days1 be+ half ! duration ( ! ,sun's axial rotation4 ,) reg>d to _! size1 spots v>y z mu* z !y d 9 _! duration4 ,! majority ( !m are telescopic1 t is1 are only visible ) ! aid ( a telescope2 b in/ances are n uncommon ( spots suffici5tly l>ge to be visible to ! nak$ eye4 ,! anci5ts knew no?+ ab\t ! physical con/itution ( ! ,sun1 & _! few allusions to ! subject 7 m]e guesses ( ! wilde/ "*4 ,!y 71 h[ev]1 able to notice n[ & !n t :5 ! ,sun 0 ne> ! horizon c]ta9 black spots c\ld sometimes be di/+ui%$ ) ! nak$ eye1 b !y took ^! = planets 9 conjunction ) ! ,sun1 or ph5om5a ( unkn[n orig94 ,e>lie/ 9 po9t ( date ( ^? :o h left on record acc\nts ( nak$ eye sun-spots are und\bt$ly ! ,*9ese4 ,9 a species ( ,cyclopdia ascrib$ to a c]ta9 ,ma-t\an-l9 7^: records ( comets h be5 ( ! greate/ possible use to a/ronom]s71 we f9d an acc\nt ( #de sun-spots se5 dur+ a p]iod ( #ijd ye>s1 f #cja ,a4 ,d4 to #abje ,a4 ,d4 ,9 ord] to convey an idea ( ! relative size ( ! spots1 ! obs]v]s comp>$ !m to eggs1 dates1 plums1 etc41 z ! case might be4 ,! obs]vations (t5 ext5d$ ov] sev]al days2 "s inde$ to z _m z t5 consecutive days1 & !re seem no gr\nds = d\bt+ ! au!nticity ( ! obs]vations ?us h&$ d[n to u4 ,a few /ray obs]vations ( sun-spots 7 record$ 9 ,europe be=e ! inv5tion ( ! telescope4 ,adelmus1 a ,b5$ict9e monk1 makes m5tion ( a black spot on ! ,sun on ,m>* #ag1 #hjg4 ,x is also /at$ t su* a spot 0 se5 by ,av]res 9 #aafa4 ,kepl] himself seems to h unconsci\sly once se5 a spot on ! ,sun ) ! nak$ eye1 ?\gh he suppos$ he 0 look+ at a transit ( ! planet ,m]cury4 ,none ( ^! e>ly obs]v]s h told u ! way 9 :i* !y made _! obs]vations1 b ! smalle/ ( boys :o has any claim to sci5tific k is aw>e ( ! fact1 t by ! use ( s simple an exp$i5t z a piece ( glass black5$ ) smoke1 spots :i* are ( suffici5t size c be se5 ) ! nak$ eye4 ,be=e telescopes came into use x 0 cu/om>y to receive ! sol> rays 9 a d>k *amb] ?r\gh a little circul> hole cut 9 a %utt]4 ,x 0 ?us t ,j4 ,fabricius succe$$ 9 ,decemb] #afaj 9 see+ a consid]able spot & foll[+ its movem5t suffici5tly well to enable him to det]m9e r\ghly ! p]iod ( ! ,sun's rotation4 ,! spots may (t5 be easily obs]v$ ) telescopes ( small dim5sions1 tak+ c>e1 h[ev]1 to place 9 front ( ! eye-piece a piece ( /rongly-col\r$ glass4 ,= ?is purpose glasses ( v>i\s col\rs are us$1 b none s good z d>k gre5 or d>k neutral t9t4 ,x is n altoge!r easy to say positively h[ l>ge a spot mu/ be = x to be visible ) ! nak$ eye1 or an op]a glass1 b probably x may be tak5 g5]ally t no spot ( less] diamet] ?an #a ( arc c be s se54 ,?is measurem5t mu/ be deem$ to apply to t c5tral portion ( a normal spot already m5tion$ z be+ :at is call$ ! nucleus1 because p5umbr may be m ?an #a 9 diamet] )\t be+ visible to ! nak$ eye1 = ! reason t _! %ad+ is s mu* less pron\nc$ ?an ! %ad+ ( umbr4 ,v l>ge & conspicu\s spots are comp>atively r>e1 ?\gh dur+ ! ye>s #ahic & #ahid !re 7 an unusual numb] ( su* spots4 ,x (t5 happ5s t a conspicu\s gr\p is ! result ( ! m]g+ or jo9+ up ( sev]al small] gr\ps4 ,9 su* cases a gr\p may ext5d ov] an area on ! ,sun #c or #d ( arc 9 l5g? by #b or #c 9 bread?4 ,! l>ge/ spot on record seems to h be5 "o se5 on ,septemb] #cj1 #aheh1 ! l5g? ( :i* 9 "o direction am\nt$ to m ?an #adj1jjj miles4 ,! obs]vation ( spots on ! ,sun by project+ !m on to a :ite pap] scre5 ) ! aid ( a telescope is a me?od s conv5i5t & s exact z to des]ve a detail$ description1 ! m s z x is s little us$4 ,let !re be made 9 ! %utt] ( a d>k5$ room a hole s mu* l>g] ?an ! diamet] ( ! telescope to be us$ z w all[ a c]ta9 am\nt ( play to ! telescope tube1 backw>ds & =w>ds1 up & d[n1 & f "r to left4 ,direct ! telescope to ! ,sun & draw out ! eye-piece to su* a di/ance f ! object-glass z t ! image project$ on a :ite scre5 held beh9d may be %>ply def9$ at its edges4 ,if !re are any spots on ! ,sun at ! "t !y w !n be se5 cle>ly exhibit$ on ! scre54 ,an image obta9$ 9 ?is way is rev]s$ z comp>$ ) ! image se5 by look+ at ! ,sun ?r\gh a telescope directly4 ,if !re=e ! telescope is arm$ ) ! ord9>y a/ronomical eye-piece1 :i* inv]ts1 !n ! projection w be direct1 t is to say1 on ! scre5 ! ,n4 ,s4 ,e4 & ,w4 po9ts w correspond ) ! same t]re/rial po9ts4 ,"u su* circum/ances ! spots w be se5 to ent] ! ,sun's disc on ! ,e4 side & to g (f on ! ,w4 side4 ,! contr>y condition ( ?+s w\ld arise if a ,galilean telescope or a t]re/rial telescope ( any k9d 7 made use (4 ,^! in/rum5ts erect ! image1 & !re=e w give by projection a rev]s$ image1 9 :i* we %all see ! spots mov+ app>5tly 9 a direction contr>y to _! true direction4 ,if ! read] has grasp$ ! broad g5]al outl9es n[ giv5 respect+ ! ,sun & its spots he w p]haps be int]e/$ to le>n a few fur!r details1 b ^! mu/ be pres5t$ 9 a some:at disjo9t$ fa%ion1 because ! multitude ( facts on record conc]n+ sun-spots are s great z to r5d] a me?odical treatm5t ( !m extremely difficult )9 ! limits "h impos$ on me4 ,^! matt]s h be5 gone into 9 a v exhau/ive way by ,sec*i 9 8 great treatise on ! ,sun1 & 9 :at foll[s ,i h made mu* use ( 8 obs]vations4 ,let u look a little fur!r into ! laws regulat+ ! movem5t ( ! spots4 ,if x is n a "q ( see+ a spot spr+ into view1 b ( wat*+ "o already 9 exi/5ce1 we %all1 9 g5]al1 see su* a spot appe> on ! ,ea/]n limb ( ! ,sun j aft] hav+ turn$ ! corn]1 s to speak4 ,! spots trav]se ! ,sun's disc 9 l9es :i* are app>5tly oblique ) ref]5ce to ! diurnal movem5t & ! plane ( ! ecliptic1 & aft] ab\t #ac days !y w disappe> at ! ,we/]n limb if !y h n done s be=e by reason ( physical *anges 9 _! condition4 ,x is n uncommon = a spot aft] rema9+ invisible = #ac days on ! o!r side ( ! ,sun1 s to speak1 to reappe> on ! ,ea/]n limb & make a second passage across ! ,sun2 sometimes a ?ird1 & inde$ sometimes ev5 a f\r?1 passage may be obs]v$1 b m g5]ally !y *ange _! =m & vani% altoge!r ei!r be=e pass+ (f ! visible disc1 or :il/ !y are on ! opposite side z view$ f ! ,e>?4 ,illu/ration3 ,fig4 #f4--;,*ange ( ,=m 9 ,sun-spots ow+ to ! ,sun's rotation4 ,:5 sev]al spots appe> simultane\sly1 !y describe 9 ! same p]iod ( "t simil> pa?s :i* are s5sibly p>allel to "o ano!r al?\gh !y may be 9 v diff]5t latitudes4 ,! conclusion f ?is is inevitable1 t spots are n bodies indep5d5t ( ! ,sun1 z satellites w\ld be1 b t !y are connect$ ) ! ,sun's surface1 & are affect$ by its movem5t ( rotation4 ,if we make e day = a few days 9 succession a draw+ ( ! ,sun's disc ) any spots t are visible duly m>k$ !reon1 we %all see t _! app>5t progress is rapid ne> ! c5tre ( ! ,sun1 b sl[ ne> ei!r limb4 ,^! diff]5ces1 h[ev]1 are app>5t & n real1 = _! movem5t appe>s to u to take place along a plane surface1 :il/ 9 reality x takes place along a circle p>allel to ! sol> equator4 ,! spots 9 approa*+ ! ,sun's ,w4 limb1 if !y happ5 to seem some:at circul> 9 =m :5 ne> ! c5tre1 fir/ become oval1 & !n seem to contract almo/ into m]e l9es4 ,^! *anges are simple effects ( p]spective1 & are to be expla9$ 9 ! same mann] z ! app>5t decrease 9 ! size ( _m ( ! spots is (t5 explicable4 ,b ?is condition ( ?+s proves1 h[ev]1 t ! spots belong to ! actual surface ( ! ,sun1 =1 on a contr>y supposition1 we %\ld h to reg>d !m z circul> bodies greatly flatt5$ l loz5ges1 & ?is w\ld be contr>y to all we "k ( ! =ms affect$ by ! heav5ly bodies4 ,( c\rse besides ! app>5t *anges ( =m j allud$ to z ! effect ( p]spective1 x is abundantly c]ta9 t sol> spots (t5 und]go v real *anges ( =m1 n only f day to day1 b 9 ! c\rse ( a few h\rs4 ,sev]al spots w (t5 become amalgamat$ into "o1 & x 0 ephem]al *anges ( ?is "* :i* h9d]$ g5]ally ! e>ly obs]v]s f det]m9+ ) precision ! duration ( ! ,sun's rotation4 ,! app>5t movem5ts ( ! spots v>y also f mon? to mon? dur+ ! ye> accord+ to ! season4 ,9 ,m>* _! pa?s are v elongat$ ellipses ) ! convexity t[>ds ! ,n41 ! long] axis ( ! ellipse be+ almo/ p>allel to ! ecliptic4 ,aft] t epo* ! curvature ( ! ellipse dim9i%es gradually1 at ! same "t t ! major axis becomes incl9$ to ! ecliptic1 s t by ,june ! flatt5+ ( ! ellipse has proce$$ s f> t ! pa? has become a /raight l9e4 ,betwe5 ,june & ,septemb] ! elliptical =m reappe>s b 9 a rev]s$ position2 !n1 foll[+ ^! rev]s$ phases1 ! ellipticity decreases1 & = ! second "t !re is an epo* ( /raight l9es4 ,?is happ5s 9 ,decemb]1 b ! /raight l9es are incl9$ 9 a conv]se direction to t :i* 0 ! case 9 ,june4 ,x mu/ aga9 be impress$ on ! read] t all ^! seem+ly diff]5t =ms ( pa? pursu$ by ! spots are m]ely effects ( p]spective1 = 9 reality1 ! spots 9 cross+ ! ,sun's disc describe l9es :i* are virtually p>allel to ! sol> equator4 ,^! projections really dep5d ( c\rse on ! position ( ! obs]v] on ! ,e>?1 & v>y z 8 position v>ies dur+ ! ,e>?'s annual circuit r\nd ! ,sun4 ,! numb] ( ! spots v>ies ?r\gh wide limits4 ,sometimes !y are s num]\s t a s+le obs]vation w enable u to recognise ! position ( ! zones ( maximum frequ5cy4 ,sometimes1 on ! o!r h&1 !y are s sc>ce1 t _m weeks may pass away )\t h>dly "o be+ se54 ,a rem>kable regul>ity is n[ recognis$ 9 ! succession ( ^! p]iods ( abundance & sc>city1 z we %all see lat] on4 ,x is bo? useful & int]e/+ 9 /udy+ ! spots to record me?odically _! numb] & _! size1 b x is n easy to tea* obs]v]s h[ to d ?is s sy/ematically t obs]vations by "o p]son c be br\ght into comp>ison ) ^? ( ano!r4 ,photography & h&-draw+ on a scre5 alone furni% a tru/wor?y basis ( op]ations4 ,spots 9 g5]al may naturally be classifi$ into 7#a7 isolat$ spots or po9ts1 & 7#b7 gr\ps ( spots2 b (t5 "o obs]v] w describe z a small spot an object :i* ano!r obs]v] w\ld reg>d z a m]e po9t2 & "o obs]v] w record sev]al gr\ps :]e ano!r obs]v] w see b "o4 ,a v few days' exp]i5ce ) a telescope w br+ home to ! obs]v]'s m9d ! difficulty ( deal+ ) ! spots :]e x is a "q ( sy/ematic me?odical obs]vation ( !m4 ,let u n[ take a brief survey ( "s ( ! !ories :i* h be5 put =? reg>d+ ! nature ( ! spots on ! ,sun4 ,9 ! e>ly days ( ! telescope1 t is to say1 dur+ ! #ag? c5tury1 two g5]al ideas 7 curr5t4 ,"s ?\ght ! spots to be %apeless satellites revolv+ r\nd ! ,sun2 o!rs t !y 7 cl\ds1 or aggregations ( smoke1 float+ ab\t 9 a sol> atmosph]e4 ,s*e9]1 ! au?or ( ! fir/ !ory1 ab&on$ x t[>ds ! close ( 8 life1 hav+ arriv$ at ! conclusion t ! spots 7 situat$ bel[ ! g5]al level ( ! ,sun's surface4 ,ano!r idea1 b ( lat] date1 0 t ! ,sun is a liquid & inc&esc5t mass ( matt]1 & ! spots imm5se fragm5ts ( ,scori1 or cl9k]s1 float+ ^u an ocean ( fire4 ,some:at m ?an a c5tury aft] ! spots _h be5 g5]ally /udi$ ) ! aid ( a telescope a ,scot*man nam$ ,wilson made a memorable discov]y4 ,he %[$ by ! cle>e/ evid5ce t !y are cavities1 & he prop\nd$ ! fir/ intelligible idea ( ! true physical con/itution ( ! ,sun1 :5 he comp>$ to a /rongly illum9at$ cl\d ! lum9\s lay] ( sol> mat]ial :i* we n[ t]m ! 8photosph]e40 ,on ,novemb] #bb1 #agfi1 he obs]v$ on ! ,sun's disc a f9e r\nd spot encompass$ by a p5umbra1 also circul>1 & conc5tric ) ! nucleus4 ,he wat*$ t spot up to ! "t t x disappe>$1 & he soon rem>k$ t ! p5umbra ceas$ to be symmetrical3 ! "p turn$ t[>ds ! c5tre ( ! ,sun became small] & small]1 & ev5tually disappe>$ altoge!r2 :il/ ! "p on ! opposite side pres]v$ its fulness & dim5sions almo/ un*ang$4 ,let u suppose we *anc$ to turn a telescope on to ! ,sun on a giv5 day1 & 7 =tunate en\gh to discov] a spot 9 ! c5tre ( ! disc1 ) a p5umbra conc5tric ) ! nucleus4 ,:5 su* a spot arrives ab\t midway t[>ds ! limb1 x w exhibit a p5umbra n>r[] on ! left side ?an on ! "r2 lat] on ! p5umbra w disappe> almo/ or q completely on ! left side3 !n ! nucleus itself w seem to be encroa*$ ^u4 ,f9ally1 v ne> ! limb1 !re w rema9 only a sl5d] ?read ( p5umbra1 & ! nucleus w h ceas$ to be directly visible4 ,su* 7 ! phases ( trans=mation obs]v$ by ,wilson & (t5 /udi$ s9ce4 ,wilson suspect$ t he _h come ^u "s great law t 0 ripe = disclosure1 & 9 ord] n to be misl$ he wait$ = ! return ( ! same spot1 :i* inde$ reappe>$ on ! ,sun's ,w4 limb aft] ab\t #ad days4 ,!n he f\nd himself face to face ) ! same phases reproduc$1 b 9 ! rev]se ord]3 ! p5umbra contract$ on "o side & full on ! o!r1 wid5+ out on ! contract$ side z ! spot came up to ! ,sun's c5tre4 ,h5ce=? d\bt 0 no long] possible2 ! spot _h s5sibly pres]v$ ! same %ape dur+ its passage1 & ! alt]ations notic$ 7 only app>5t1 & result$ f an effect ( p]spective :i* 0 easy to be und]/ood4 ,! diff]5t phases pres5t$ by su* a spot z t j spok5 ( w be s mu* ! m s5sible accord+ z ! dep? ( ! cavity is great]2 b if ! dep? is inconsid]able ! bottom ( ! cavity w only disappe> :5 a v oblique angle is atta9$1 & ?is _c happ5 except :5 ! spot is v ne> to ! limb4 ,by obs]vations c>efully made "u su* circum/ances x w be possible to det]m9e ! dep? ( ! cavity1 & ,wilson f\nd t ! dep? ( a spot (t5 am\nt$ to ab\t "o-?ird ( ! ,e>?'s radius4 ,wilson's !ory 0 n accept$ )\t dispute2 x 0 conte/$ by sev]al a/ronom]s1 & 9 p>ticul> by ,lal&e4 ,x 0 h[ev] tak5 up by ,sir ,w4 ,h]s*el1 & z modifi$ by him has met ) g5]al acceptance d[n to ! pres5t "t2 ?\gh n[ & aga9 *all5g$1 p]haps mo/ rec5tly & mo/ vehem5tly by ,h[lett1 a sun spot obs]v] ( great exp]i5ce4 ,wilson's discov]y 0 ! po9t ( dep>ture = ! gr& lab\rs ( ,sir ,w4 ,h]s*el 9 ! field ( ,sol> ,physics4 ,man ( g5ius t ,h]s*el 01 he 0 above all ?+s an obs]v] :o took 8 own l9e 9 :at he did4 ,he saw s _m ph5om5a ) ! p[]ful in/rum5ts con/ruct$ by himself1 he describ$ s m9utely ! m>vels :i* 7 reveal$ to him1 t he left comp>atively little = 8 successors to d s f> z reg>ds m]e telescopic obs]vation4 ,h]s*el's ma9 idea z to ! ,sun 0 bas$ on ,wilson's discov]y4 ,he rem>k$ ) reason1 z t a/ronom] _h done1 t if ! spots are cavities ! lum9\s matt] c\ld nei!r be prop]ly call$ liquid nor gase\s2 = !n x w\ld precipitate itself ) frightful rapidity to fill up ! void1 & t w\ld r5d] x impossible t ! spots %\ld endure z we (t5 see !y d dur+ sev]al revolutions ( ! ,sun4 ,moreov]1 ! prop] movem5ts ( ! spots prove t ! photosph]e is n solid4 ,we c !re=e only lik5 x to fogs or cl\ds1 & x mu/ be susp5d$ 9 an atmosph]e simil> to ours4 ,su* is1 accord+ to ,h]s*el1 ! only hypo!sis :i* c expla9 ! rapid *anges :i* we witness4 ,we %all see a little lat] on t ^! ph5om5a d admit ( ano!r explanation4 ,9 a second memoir ,h]s*el foll[$ up ?is inquiry ) an acut5ess wor?y ( 8 g5ius4 ,un=tunately he all[$ himself to be c>ri$ away ) ! idea t ! ,sun 0 inhabit$ 9 ord] to su/a9 ?is !ory4 ,he ne$$ a solid k]nel ^u :i* 8 imag9>y inhabitants c\ld dwell2 & also a means :]eby he c\ld protect !m f ! radiations ( ! photosph]e4 ,) ?is idea 9 view he conjectur$ ! exi/5ce above ! ,sun's solid body ( a lay] ( cl\ds always contigu\s to ! photosph]e :i* envelop$ x1 & :i* always be+ r5t :5 ! photosph]e 0 r5t1 ?us enabl$ u to see ! solid body ( ! ,sun ly+ beh9d4 ,^! notions c only be describ$ z v arbitr>y1 z unsupport$ by obs]vation1 & z involv+ explanations q out ( h>mony ) ! pr9ciples ( mod]n physics4 ,h[ev]1 ! lab\rs ( ,h]s*el result$ 9 s _m positive discov]ies ( visible facts1 & 9 s _m j conclusions1 t !y contribut$ greatly to ! gr[? ( our pres5t k ( ! true con/itution ( ! ,sun4 ,s9ce ,wilson's "t1 z ,sec*i po9t$ly rem>ks1 a/ronom]s g5]ally h v]ifi$ 8 obs]vations ) good in/rum5ts1 & by an inve/igation ( a great numb] ( spots4 ,de ,la ,rue1 discuss+ ! ,kew obs]vations1 f\nd t ( #hi regul> spots #gb gave results :i* con=m$ to ,wilson's ideas1 :il/ ! rema9+ #ag 7 oppos$ !reto4 ,!re is no?+ surpris+ 9 ! exi/5ce ( a contr>i5t m9ority :5 we consid] ! great *anges :i* 9 reality (t5 occur 9 ! =ms ( ! spots4 ,de ,la ,rue sugge/$ a v simple exp$i5t = %[+ t ! spots are cavities4 ,take two photographs ( ! ,sun made at an int]val ( "o day3 dur+ t "t e po9t on ! ,sun's surface w h be5 displac$1 s f> z ! telescope is conc]n$1 by ab\t #ae4 ,place ^! photographs 9 a /]eoscope1 & we %all readily see ! int]ior cavity1 ! edges ( :i* w appe> rais$ above ! photosph]e4 ,x is impossible !re=e to ent]ta9 ! lea/ d\bt z to ! tru? ( ! !ory t ! spots are excavations 9 ! lum9\s /ratum :i* envelopes ! :ole ( ! sol> globe4 ,if x be true t a spot is a cavity1 x foll[s t :5 x rea*es ! m>g9 ( ! sol> disc we ought to detect a holl[ place2 & ?is w be s mu* ! m easy to obs]ve accord+ z ! cavity is l>g] & deep]4 ,z a matt] ( fact1 num]\s obs]vations ( ?is sort h be5 record$ f ! "t ( ,cass9i d[n to ! pres5t "t "u ! designation ( 8not*es0 on ! ,sun's limb4 ,on ,july #h1 #ahgc1 ,sec*i obs]v$ su* a not* #h1 or #cfjj miles deep4 ,faye & "s o!r a/ronom]s are dispos$ to support a !ory accord+ to :i* ! spots are no?+ else ?an arial cyclones1 b ?is does n seem admissible4 ,if ! fundam5tal pr9ciple ( a spot is t x arises f a :irl+ movem5t1 ! rays 7s to speak7 :i* compose ! p5umbr mu/ always be crook$1 or ! !ory falls to ! gr\nd4 ,x is q true t indications ( cyclonic action d sometimes appe>1 b !y are at any rate v r>e1 = only a small p]c5tage exhibit 9 a di/9ct mann] a spiral /ructure4 ,moreov]1 :5 su* a /ructure is se5 x does n endure = ! :ole lifetime ( ! spot b only = a day or two3 ! spot may la/ a long "t aft] x has lo/ its spiral features1 if x ev] _h any4 ,sometimes ev5 ! :irl+ movem5t1 aft] hav+ slack5$1 beg9s aga91 b 9 ! contr>y direction4 ,"u ^! circum/ances1 ?\gh ?is occasional spiral /ructure is v curi\s & int]e/+1 we are n ju/ifi$ 9 tak+ x z ! basis ( a !ory :i* has any pret5sions to expla9 ! g5]al nature ( sun-spots4 ,illu/ration3 ,fig4 #g4--,sun-spot se5 z a ,not*4 ,:5 we exam9e ! ,sun ) in/rum5ts ( l>ge ap]ture & high magnify+ p[]1 we notice t its surface is f> f be+ z smoo? & uni=m z x appe>s 9 a small telescope4 ,on ! contr>y1 x pres5ts an irregul> undulat+ appe>ance l a pond or o!r %eet ( wat] agitat$ by ! w9d4 ,c>eful scrut9y ) a p[]ful eye-piece reveals ! fact t ! ,sun's surface is m>k$ by a multitude ( wr9kles & irregul>ities :i* x is well-nigh impossible to describe 9 words4 ,m or less ev]y:]e !re is a g5]al mottl+ visible2 x is m di/9ct 9 "s places ?an o!rs1 & especially s t[>ds ! c5tre ( ! disc4 ,?is peculi> appe>ance v>ies v mu* f "t to "t1 & its di/9ctness seems to dep5d a great deal on ! /ate ( ! ,e>?'s atmosph]e1 = x becomes invisible :5 ! air is di/urb$2 b ^! v>iations dep5d also on real v>iations ( ! photosph]e--a fact :i* obs]vations made 9 v calm wea!r are ?\ght cle>ly to indicate4 ,x is (t5 said t ! ,sun exhibits a granulat$ /ructure4 ,if we wi% to realise 9 ! mo/ precise mann] :at is meant by ! ^w 8granulation0 z appli$ to ! /ructure ( ! ,sun1 we mu/ ab&on ! me?od ( projection & exam9e ! ,sun directly ) a p[]ful eyepiece1 tak+ advantage ( a mom5t :5 ! atmosph]e is p]fectly calm1 & be=e ! eyepiece has _h "t to get hot4 ,x may !n be se5 t ! ,sun's surface is cov]$ ) a multitude ( little gra9s1 ne>ly all ( ab\t ! same size1 b ( diff]5t %ape1 ?\gh = ! mo/ "p m or less oval4 ,! small int]/ices :i* sep>ate ^! gra9s =m a network :i* is d>k )\t be+ positively black4 ,sec*i consid]$ x difficult to "n any kn[n object :i* exactly answ]s 9 appe>ance to ?is /ructure1 b he ?\ght t we c f9d some?+ resembl+ x 9 exam9+ ) a microscope milk :i* has be5 a little dri$ up1 & ! globules ( :i* h lo/ _! regul> =m4 ,exceptionally good atmosph]ic conditions are "u all circum/ances indisp5sable = ! /udy ( ^! details4 ,9 po9t ( fact1 !re is a my/]i\s unc]ta9ty ab\t ! normal condition ( ! ,sun's surface1 9 a visual s5se1 :i* a few ye>s ago eng5d]$ a v vehem5t controv]sy1 & l$ to ! use ( su* expressions z 8will[ leaves10 8rice gra9s10 8sea bea*10 & 8/raw ?at*+10 to indicate :at 0 se54 ,all ^! words are too precise to be q suitable to be tak5 lit]ally1 b p]haps1 on ! :ole1 8rice gra9s0 is n altoge!r a bad expression to recall :at c]ta9ly seems to be ! granul> surface ( ! ,sun z we see x4 ,by mak+ use ( mod]ate magnify+ p[]s1 :at we see w (t5 convey ! impression ( a multitude ( :ite po9ts on a black network4 ,?is is v app>5t dur+ ! fir/ few mom5ts t ! telescope is br\ght to be> on ! ,sun1 b its cle>ness quickly passes away because ! eye gets fatigu$1 & ! l5ses becom+ w>m ! air 9 ! telescope tube gets di/urb$ because also w>m$4 ,sometimes ! appe>ance is a little diff]5t f t j describ$1 & along ) ! :ite & brilliant po9ts little black holes are int]mix$4 ,(t5times ! gra9s appe> z if susp5d$ 9 a black network & heap$ toge!r 9 knots m or less %ad$ & m or less broad4 ,sometimes ! gra9s exhibit a v elongat$ =m1 especially 9 ! neighb\rhood ( ! spots4 ,x is ^! elongat$ =ms to :i* ,nasmy? appli$ ! t]m 8will[ leaf10 :il/ ,hugg9s ?\ght 8rice gra9s0 a v suitable expression4 ,?is granul> or leaf-l /ructure--call x :at we w--_c be made out except ) consid]able optical assi/ance1 = ! gra9s be+ intr9sically v small1 diffraction 9 enl>g+ !m & caus+ !m to encroa* on "o ano!r necess>ily produces a g5]al confusion ( image4 ,! real dim5sions ( ^! gra9s _c !re=e readily be det]m9$ by direct measurem5t1 b by comp>+ !m ) ! wires us$ 9 micromet] eye-pieces x has be5 ?\ght t _! diamet]s may usually be reg>d$ z equal to or ( a second--say f #abj to #aej miles4 ,! granules seem to be possess$ ( s5sible movem5t1 b presumably x is n always or ev5 g5]ally a movem5t ( translation f place to place2 only an undulatory movem5t l t ( /ill wat] :5 a /one is ca/ into x4 ,nev]!less1 probably 9 c]ta9 cases ! granules actually are affect$ by a motion ( translation1 = 9 ! vic9ity ( spots !y may sometimes be se5 fl[+ ov] ! edges ( ! p5umbr4 ,9 ord] to expla9 ! exi/5ce ( ! granules ! /range/ !ories h be5 broa*$4 ,sir ,william ,h]s*el hav+ obs]v$ ! granulations1 appli$ to !m ! t]m 8corrugations0 or 8furr[s0--words some:at inexact1 p]haps1 b by :i*1 z 8 descriptions cle>ly %[1 he meant to designate ! features :i* ,i am n[ treat+ (4 ,he ev5 notic$ ! d>k network :i* sep>ates ! gra9s1 & he appli$ to x ! ^w 8ind5tations40 ,^! granulations are )\t d\bt prom95ces1 probably ( hydrog5 gas1 :i* rise above ! g5]al surface1 = ?is /ructure is mu* m %>p & di/9ct at ! c5tre ( ! sun's disc ?an at ! limbs2 t is to say1 ne> ! limbs ( ! ,sun !y p>tially ov]lap "o ano!r1 z inde$ ,h]s*el rem>k$4 ,! idea ( flames w\ld satisfy ^! appe>ances3 & z ! spectroscope sugge/s to u t ! ,sun is habitually cov]$ ov] ) a multitude ( little jets ( flame1 ! obs]vations :i* h be5 made compel ! op9ion t ! gra9s are ! summits ( ^? prom95ces :i* exi/ all ov] ! ,sun's surface4 ,! surface is sometimes s ?ickly cov]$ ov] ) ^! granulations--! network is s conspicu\s--t we c readily imag9e t we see ev]y:]e pores & ! beg9n+s ( spots1 b ?is aspect is n p]man5t1 & seems to dep5d to "s ext5t on atmosph]ic causes comb9$ also ) actual *anges 9 ! ,sun's surface itself4 ,!re seems h[ev] no d\bt t ! jo9ts1 s to speak1 ( ! d>k network already ref]r$ to d sometimes bur/ asund] & develope into spots4 ,! circum/ances :i* accompany ! =mation ( a spot _c readily be specifi$ ) c]ta9ty4 ,x is impossible to say t !re exi/s any law z to ?is matt]4 ,:il/ "s spots develope v sl[ly by ! expansion ( c]ta9 pores1 o!rs spr+ into exi/5ce q sudd5ly4 ,yet x _c be said t ! =mation ( a spot is ev] completely in/antane\s h[ev] rapid x may be4 ,! ph5om5on is (t5 ann\nc$ "s days 9 advance3 we may p]ceive 9 ! photosph]e a great agitation :i* (t5 manife/s itself by "s v brilliant facul 7to be describ$ pres5tly7 giv+ bir? to "o or m pores4 ,v (t5 we next notice "s gr\ps ( little black spots1 z if ! lum9\s /ratum 0 becom+ ?9n] 9 su* a way z to disappe> little by little & leave a l>ge black nucleus uncov]$4 ,at ! comm5cem5t ( ! bus9ess !re is usually no cle>ly def9$ p5umbra4 ,?is developes itself gradually & acquires a regul> outl9e1 j z ! spot itself (t5 takes a some:at circul> =m4 ,?is tranquil & peaceable =mation ( a spot only happ5s at a "t :5 calm seems to reign 9 ! sol> atmosph]e3 9 g5]al ! developm5t is m tumultu\s & ! /ages m complicat$4 ,z a rule a spot passes ?r\gh ?ree /ages ( exi/5ce3--7#a7 ! ,p]iod ( bir?2 7#b7 a ,p]iod ( calm2 & 7#c7 ! ,p]iod ( dissolution4 ,:5 a spot is on ! po9t ( clos+ up1 ! fl[ ( ! lum9\s matt] :i* x1 z x 71 attracts1 is n direct$ uni=mly t[>ds ! c5tre2 x seems t ! photosph]ic masses1 no long] meet+ ) resi/ance1 are precipitat$ promiscu\sly any:]e s z to fill up ! hole4 ,x is impossible to describe 9 detail ! phases :i* irregul> spots g ?r\gh1 b two ?+s may always be rem>k$3 t _! /ructure is *>act]iz$ by ! exi/5ce ( lum9\s filam5ts1 & t ^! filam5ts conv]ge t[>ds "o or sev]al c5tres4 ,sec*i ?us sums up c]ta9 conclusions :i* he arriv$ at relat+ to spots g5]ally3--7#a7 ,x is n on ! surface ( any solid body t ! sol> spots are manife/$2 !y are produc$ 9 a fluid mass1 ! fluidity ( :i* is repres5t$ by a gas1 s t ! con/itution ( ?is m$ium may be lik5$ to t ( flames or cl\ds2 7#b7 ! kn[n details respect+ ! con/itution ( ! p5umbra & ! ph5om5a exhibit$ prove t ! p5umbra is n a mass ( obscure matt] :i* floats across lum9\s matt]1 b t x is on ! contr>y a case ( lum9\s matt] invad+ & float+ ab\t ov] d>k] mat]ials & s produc+ a half t9t4 ,all ! available evid5ce :i* we possess may be said to %[ t ! spots are n m]ely sup]ficial appe>ances1 b t !y h _! orig9 deep 9 ! int]ior ( ! ,sun1 & are produc$ by ! op]ation ( causes /ill unkn[n to u :i* affect & di/urb ! ,sun's mass to an ext5t :i* is sometimes v consid]able4 ,! spots !n are only ! results ( a great agitation 9 ! mat]ials ( :i* ! ,sun is compos$1 & ?is agitation ext5ds f> d[n bel[ ! limits ( ! visible d>k nucleus :atev] t may consi/ (4 ,besides ! spots1 /reaks ( light may frequ5tly be rem>k$ ^u ! surface ( ! ,sun t[>ds ! m>g9 ( ! disc4 ,^! are t]m$ facul 7tor*es71 & !y are (t5 f\nd ne> ! spots1 or :]e spots h previ\sly exi/$ or h aft]w>ds appe>$4 ,:5 q ne> ! ,sun's limb ^! facul are usually m or less p>allel to ! limb4 ,!y are ( irregul> =m & may be lik5$ to c]ta9 k9ds ( coral4 ,!y g5]ally appe> to be m lum9\s ?an ! sol> surface imm$iately adjac5t to !m1 b x is n improbable t ?is is an optical illusion dep5d+ ^u ! fact t ! edges ( ! ,sun always appe> mu* m lum9\s ?an ! c5tre4 ,?is la/-nam$ fact may be readily recognis$ by ! employm5t ( a high magnify+ p[]1 & mov+ ! telescope rapidly f ! limb to ! c5tre ( ! disc4 ,if ! ,sun be project$ on a scre51 z already m5tion$1 ?is degradation ( ! ,sun's light f c5tre to circumf]5ce becomes p>ticul>ly manife/4 ,aft] hav+ /udi$ ! /ructure & ! movem5t ( ! spots1 "o is naturally l$ to ask if _! app>itions at diff]5t p]iods are subject to any g5]al law4 ,?is "q is "o :i* has mu* engag$ ! att5tion ( mod]n a/ronom]s4 ,! old] obs]v]s notic$ t ! numb] ( ! spots visible diff]$ 9 diff]5t ye>s4 ,!re 7 said to h be5 p]iods :5 mon?s & ev5 ye>s pass$ away )\t any spots be+ obs]v$4 ,ev5 all[+ t ?is /atem5t1 s f> z 8ye>s0 are conc]n$1 might be exagg]at$1 & t ! abs5ce ( spots 0 due to ! want ( suffici5t c>e 9 mak+ ! obs]vations1 & especially to ! want ( effici5t in/rum5ts1 x is none ! less true t ! numb] ( ! spots is extremely v>iable1 & t !re h be5 epo*s :5 !y 7 v sc>ce4 ,sir ,w4 ,h]s*el 0 ! fir/ :o devot$ himself to ! "q ( seek+ to e/abli% a relation betwe5 ! v>iation ( ! spots & t]re/rial meteorology4 ,= ! want ( any bett] object1 he comp>$ ! annual numb] ( ! spots ) ! price ( :eat2 b x is easy to see t no?+ c\ld result f su* a comp>ison4 ,)\t d\bt ! meteorological ph5om5a ( ! globe mu/ dep5d to "s ext5t on sol> *anges3 b ! t]m ( comp>ison select$ by ,h]s*el _h no direct be>+ on ! /ate ( ! ,sun4 ,9 our "t ?is "q has be5 inve/igat$ to its v f\ndation by ,wolf1 ,director = _m ye>s at ! ,obs]vatory ( ,zuri*4 ,x is to 8 zeal t we owe a v int]e/+ assemblage ( old obs]vations :i* 7 buri$ 9 ar*ives & *ronicles4 ,x 0 he :o endeav\r$ to r$uce !m into a sy/ematic =m1 s z to supply z f> z possible ! num]\s gaps :i* exi/ 9 ! diff]5t s]ies4 ,! two mo/ att5tive obs]v]s at ! p]iod :5 ! spots 7 discov]$ 7 ,m>riott at ,ox=d & ,s*e9] at ,+old/adt1 b ,s*e9] himself has in=m$ u t he did n note d[n all ! spots :i* he saw2 he only record$ ^? :i* 7 likely to assi/ him 9 8 special task ( det]m9+ ! p]iod ( ! ,sun's rotation4 ,sev]al obs]v]s aft] him made isolat$ s]ies ( obs]vations2 b "s ( ^! h be5 lo/ & ! o!rs %[ important gaps4 ,j4 ,g4 ,/auda*]1 at ,nuremburg1 obs]v$ ! ,sun ) great p]sev]ance dur+ fifty ye>s f #agdi to #agii4 ,be=e him ! ,cass9is1 ,m>aldi1 & o!rs 7 engag$ 9 ! same sort ( "w1 b only 9 an indirect way3 t is to say1 !y cont5t$ !mselves1 :il/ mak+ m]idional obs]vations ( ! ,sun1 ) not+ any?+ 9 ! way ( spots :i* !y deem$ important4 ,zucconi & ,flaug]gues also left beh9d !m a good collection ( obs]vations :i* ,wolf utilis$1 r5d]+ !m comp>able "o ) ano!r by apply+ suitable corrections4 ,! great difficulty h]e9 arises f ! fact t ! obs]v]s 7 n provid$ ) in/rum5ts ( equal p[]2 "o man1 arm$ ) a bett] telescope ?an 8 contempor>ies1 naturally obs]v$ & record$ spots :i* w\ld escape ! o!rs4 ,! numb]s ent]$ 9 _! regi/]s are !re=e n comp>able int] se4 ,wolf endeav\r$ to replace ^! numb]s by o!rs :i* w\ld repres5t ! spots :i* might h be5 se5 if ! obs]v]s _h all employ$ telescopes ( a giv5 k9d & p[]4 ,! result ( 8 ef=ts 9 ?is direction is an almo/ cont9u\s s]ies ( ,sun-spot records f an epo* suffici5tly remote1 up to ! "t :5 ?is bran* ( sci5ce 0 tak5 up ) ! vig\r ( mod]n sci5tific me?ods4 ,! obs]v] :o mo/ assidu\sly devot$ himself to ?is subject 9 mod]n times 0 ,s*wabe ( ,dessau4 ,f #ahbf to #ahfh he nev] fail$ to make daily obs]vations :5 ! wea!r p]mitt$ him4 ,8 s]ies ( records is specially valuable1 = ,c>r+ton's fits 9 ) x1 & ) t 9 turn ,spr]'s is comp>able1 & ! *a9 is complete by ! lat] photographic & o!r obs]vations4 ,all ^! ,sun-spot records1 ?\gh diff]+ 9 _! details1 may easily be us$ toge!r :5 x is a "q ( work+ out relative annual fluctuations4 ,at ! pres5t "t !re are _m ,a/ronom]s :o are engag$ 9 obs]v+ ! spots ) c>e2 b j z =m]ly !re are few :o possess suffici5t p]sev]ance4 ,! photographic me?od is excell5t1 b x takes mu* "t & is co/ly4 ,"s h decri$1 9 a v unreasonable mann]1 a draw+ made by h&3 su* a draw+1 ( suffici5t size1 & execut$ by projection by a skilful draughtsman ) a telescope driv5 by clockwork1 may /& comp>ison ) a photograph1 & ?is me?od has a bett] *ance ( be+ p]sev]$ 94 ,! ,rev4 ,f4 ,h[lett's "n mu/ be m5tion$ 9 ?is connection z a draughtsman :o has accompli%$ mu* by h& draw+4 ,?\gh ! once fam\s ,kew obs]vations h be5 discont9u$1 !y h be5 replac$ by a new s]ies at ,gre5wi* ) simil> appliances2 :il/ ,janss5 at ,meudon has also be5 c>ry+ on = a numb] ( ye>s a spl5did c\rse ( photographic records4 ,s*wabe1 :5 he _h collect$ a consid]able numb] ( obs]vations1 recognis$ cle> indications ( p]iodicity4 ,v def9ite epo*s ( maxima & m9ima succe$$ "o ano!r at int]vals ( #aj or #aa ye>s4 ,x is true t 9 foll[+ out su* a /udy ! obs]vations are c]ta9 to be 9 a s5se a little defective4 ,at fir/ x 0 n possible to obs]ve ! ,sun e day1 & ! gaps :i* result$ f bad wea!r necess>ily add$ to ! numb] ( days :i* _h to be set d[n z be+ )\t spots4 ,moreov]1 e me?od ( numb]+ ! spots mu/ be a little arbitr>y3 !re are (t5 gr\ps :i*1 9 consequ5ce ( _! sub-divisions1 may be c\nt$ 9 diff]5t ways3 b 9 a mass ( obs]vations s consid]able z ^? ( ,s*wabe's1 su* unc]ta9ties w comp5sate = "o ano!r & w disappe> 9 ! f9al result4 ,9 fact ! law is s /rik+ t x suffices to ca/ "o's eye ov] 8 table#b to see t4 ,t table is bo? int]e/+ & in/ructive at ! same "t4 ,! numb]s exhibit$ 9 x speak = !mselves1 & x is suffici5t to exam9e !m ) ev5 a small am\nt ( att5tion to realise ! c]ta9ty ( ! conclusions :i* h be5 drawn4 ,x is !re=e n[ to be deem$ an asc]ta9$ fact t !re are p]iodical maxima & m9ima 9 ! display ( spots1 & t ! ext5t ( ! p]iod is betwe5 #aj & #ab ye>s4 ,9 ord] to det]m9e ?is value ) ! utmo/ exactness1 "s a/ronom]s h _h rec\rse to e>ly obs]vations4 ,wolf ( ,zuri* made ?is ! subject ( "s v int]e/+ inquiries4 ,he 0 able to e/abli% ! *ronology ( ! phases :i* ! ,sun has pass$ ?r\gh f ! "t ( ! fir/ discov]y ( ! spots to ! pres5t day--m ?an #b c5turies4 ,8 calculations l$ him to a p]iod ( #aa-a_/i ye>s4 ,lamont fix$ ^u #aj4dc ye>s1 b ?is numb] does n repres5t ! m rec5t obs]vations ) suffici5t precision4 ,9 ord] to exhibit ?is law 9 ! pla9e/ possible mann] ! dates ( maxima & m9ima %\ld be laid d[n on rul$ pap] 9 prop] ma!matical =m1 ! absciss ( ! curve repres5t+ ! ye>s1 & ! ord9ates ! numb] ( spots obs]v$4 ,an exam9ation ( a curve ?us plott$ %[s two ?+s3--7#a7 ,t ! p]iod is cle>ly an elev5-ye> "o1 z has be5 already /at$2 7#b7 t x is n h[ev] q z simple 9 its =m z x 0 at fir/ ?\ght to be2 = 9 reality !re are two p]iods sup]pos$1 ! "o r m ?an half a c5tury long1 & ! o!r ext5d+ ov] ! #aa ye>s already spok5 (4 ,we d n possess e>ly obs]vations suffici5tly num]\s & suffici5tly good to enable u to draw any unimpea*able conclusions z to ! nature ( ! long p]iod2 we c only be c]ta9 t x exi/s4 ,! lat] lab\rs ( ,wolf1 h[ev]1 fix$ t p]iod at #ee ye>s4 ,x is a result ( ?is t1 accord+ to ,loomis1 a p]iod ( comp>ative calm on ! ,sun exi/$ betwe5 #ahaj & #ahbe4 ,ea* maximum lies ne>] to ! m9imum :i* prec$es x ?an to ! m9imum :i* foll[s x1 = ! spots increase dur+ #c4g ye>s1 & !n dim9i% dur+ #g4d ye>s4 ,accord+ to ,de ,la ,rue ! increase occupies #c4eb ye>s1 & dim9ution #g4ee ye>s4 ,?is concurr5ce betwe5 ,de ,la ,rue & ,wolf is surpris+ consid]+ ! div]sity ( ! me?ods :i* l$ to results almo/ id5tical1 ! "o set be+ bas$ on ! numb] ( ! spots1 & ! o!r on ! sup]ficial ext5t ( ! spots4 ,! diff]5t p]iods 9 succession are n absolutely id5tical3 b x has be5 rem>k$ t if dur+ any "o p]iod ! decrease is ret>d$ or accel]at$1 !n ! increase next foll[+ w be l5g!n$ or contract$ to a correspond+ ext5t4 ,9 consequ5ce ( ?is we are sometimes able to pr$ict ) fair accuracy :5 ! next ensu+ maximum or m9imum w take place4 ,! mo/ /rik+ feature ( su* a curve z t j allud$ to is ! v s5sible second>y augm5tation :i* happ5s v soon aft] ! pr9cipal maximum4 ,a v curi\s circum/ance has come to light 9 connection ) ! epo*s ( maxima & m9ima4 ,9 arrang+ ! spots accord+ to _! latitude & longitude on a diagram suffici5tly contract$1 ,c>r+ton f\nd t _! latitude decreases gradually z ! p]iod ( m9imum draws ne>2 !n :5 _! numb] beg9s to increase !y beg9 to appe> aga9 at a high] latitude4 ,?is seems to be a def9ite law4 ,at any rate ,c>r+ton's conclusion has be5 f\nd to hold good by ! obs]vations ( ,spr] & ,sec*i4 ,! v>iations ( ! spots :i* we n[ recognise naturally recall ^? obscurations ( ! ,sun :i* are record$ 9 hi/ory2 b x is necess>y to accept _m ( ^! ) caution4 ,a great numb] ( ^! ph5om5a :i* attract$ ! att5tion ( p 9 e>ly times are only eclipses badly obs]v$ & /ill m badly describ$4 ,9 o!r in/ances ! obscuration has be5 produc$ by v protract$ dry fogs4 ,x is probably to ?is la/-nam$ cause t we mu/ ascribe ! obscuration :i*1 accord+ to ,kepl] & ,gemma ,frisius1 took place 9 #aedg4 ,x 0 9 "s su* way z ?is t1 accord+ to ,virgil 7,georg4 i1 #fcj71 :o has e*o$ a tradition :i* he f\nd 9 hi/ory1 ! ,sun 0 obscur$ at ! dea? ( ,cs>3-- ,ille etiam ext9cto mis]atus ,cs>e ,romam ,quum caput obscura nitidum f]rug9e texit1 ,impiaque t]nam timu]unt scula noctem4 ,9 ! ye> #eec ,a4,d41 & aga9 9 ! ye> #fbf ,a4,d4 ! ,sun rema9$ obscur$ = sev]al mon?s2 b ^! facts 7if facts !y are7 besides be+ ill-obs]v$1 & clo!d1 no d\bt1 9 extremely exagg]at$ language1 are br\ght to our notice z hav+ occurr$ at epo*s :i* are q indep5d5t ( "o ano!r1 :il/ ! v>iations 9 ! m>k+s on ! ,sun1 :i* we h j be5 talk+ ab\t1 pres5t an almo/ ma!matical regul>ity ( sequ5ce4 ,we mu/ n[ in/itute "s inquiries z to ! causes ( ! p]iodicity ( ! spots4 ,a p]iodicity s well e/abli%$ w\ld naturally invite a/ronom]s to seek ! causes :i* produc$ x4 ,! pres5ce ( spots only 9 ! ,zodiacal regions l$ ,galileo to suspect ! exi/5ce ( "s relation betwe5 ! spots & ! position ( ! planets2 b !re is 9 ?is a m]e surmise1 :i*1 :5 x 0 made1 _h no?+ to ju/ify x1 & x is /ill impossible = u to say any?+ = c]ta9 on ! po9t4 ,! det]m9+ cause ( ! p]iodicity may exi/ 9 ! int]ior ( ! ,sun1 & may dep5d on circum/ances :i* w = ev] rema9 unkn[n to u4 ,or x may be some?+ ext]nal3 x may be due aft] all to ! influ5ce ( ! planets4 ,x rema9s = u1 !re=e1 to se>* & see if any su* influ5ce c be trac$4 ,accord+ to ,wolf1 ! attraction ( ! planets1 or ( "s ( !m1 is ! real cause ( ! p]iodicity :i* we are deal+ )2 t attraction produc+ on ! surface ( ! sol> globe true tides1 :i* give bir? to ! spots1 ^! tides !mselves exp]i5c+ p]iodic v>iations ow+ to ! p]iodic *anges ( position ( ! cele/ial bodies :i* cause !m4 ,x has ev5 be5 ?\ght safe to ass]t t ! fact ( ! pr9cipal p]iod co9cid+ ) ! revolution ( ,jupit] is ( mom5t\s significance2 b ?is co9cid5ce seems purely accid5tal1 & no c]ta9 conclusion c be drawn z to ?is matt]4 ,! influ5ce ( ,m]cury & ,v5us w\ld p]haps be mu* m pot5t1 = _! di/ance f ! ,sun is n v great1 & ?is %\ld r5d] _! influ5ce m s5sible4 ,on ! o!r h&1 _! masses appe> to be too small to be capable ( produc+ any suffici5t effect4 ,de ,la ,rue1 ,balf\r ,/ew>t1 & ,lwy mo/ p]sev]+ly /udi$ ?is po9t ( sol> physics4 ,!y seem to h arriv$ at ! conclusion t ! conjunctions ( ,v5us & ,jupit] d ex]cise a c]ta9 am\nt ( influ5ce on ! numb] ( ! spots & on _! latitude2 & t ?is influ5ce is less consid]able :5 ,v5us is situat$ 9 ! plane ( ! sol> equator4 ,at any rate x is a fact1 t a great numb] ( ! visible inequalities 9 a duly plott$ curve ( ! spots d really correspond to special positions ( ^! two planets4 ,9 ord] to det]m9e ) m precision ^! co9cid5ces & ! importance :i* atta*es to !m1 ,de ,la ,rue ext5d$ 8 inquiries4 ,he sep>ately analys$ _m diff]5t gr\ps ( spots1 select+ = 8 purpose m p>ticul>ly ^? ( :i* ! obs]vations happ5$ to h be5 specially cont9u\s & complete1 giv+ a pref]5ce moreov] to ^? :i* _h be5 obs]v$ 9 ! c5tral portions ( ! ,sun's disc4 ,f an inve/igation ( #gid gr\ps ,de ,la ,rue arriv$ at ! foll[+ conclusions3--7#a7 ,if we take a m]idian pass+ ?r\gh ! middle ( ! disc & repres5t$ by a diamet] p]p5dicul> to ! equator1 we f9d t ! mean size ( ! spots is n ! same ) reg>d to t m]idian4 ,x appe>s c]ta9 t ! correction requir$ = p]spective does n suffice to expla9 ?is diff]5ce2 & t ano!r elem5t mu/ be introduc$ 9 ord] to secure t ! app>5t dim5sions ( ! spots may be ! same on bo? sides4 ,we d n yet possess a v cle> explanation ( ?is fact2 b ! mo/ probable is ?is3--! spots are surr\nd$ by a project+ bank1 :i* seems to disappe> 9 "p dur+ _! transit across ! ,sun4 ,?is bank is m elevat$ on ! prec$+ ?an on ! foll[+ side2 accord+ly1 ! spots ought to seem small] :5 !y are 9 ! ea/]n half ( ! disc2 l>g] :5 !y are 9 ! we/]n half2 = 9 ! fir/ position ! obs]v]'s eye meets an elevat$ ob/acle1 :i* hides a portion ( ! spot itself4 7#b7 ,de ,la ,rue specially /udi$ ! spots obs]v$ at ! times :5 ! planets ,v5us & ,m>s 7 at a helioc5tric di/ance f ! ,e>? equal to #j1 #ij1 #ahj1 & #bgj degrees1 & arriv$ at ?is result2 ! spots are l>g] 9 ! "p ( ! ,sun :i* is away f ,v5us & ,m>s1 & !y are small] on ! side on :i* ^! planets happ5 to be4 ,! same result 0 obta9$1 :e!r ,c>r+ton's figures or ! ,kew photographs 7 employ$4 7#c7 ,mean:ile x does n appe> t ,jupit] emits any simil> influ5ce4 ,?is influ5ce %\ld be easily p]ceiv$1 = if we calculate ! action ( ! planets 9 ! way t we calculate ! tides1 treat+ x z directly proportional to ! masses & inv]sely proportional to ! cubes ( ! di/ances1 ! influ5ce ( ,jupit] %\ld greatly outweigh t ( ,v5us4 ,wolf ?\ght t he _h notic$ traces ( "s influ5ce be+ ex]t$ by ,saturn2 b ?is rema9s altoge!r )\t confirmation4 ,de ,la ,rue notic$ t l>ge spots are g5]ally situat$ at extremities ( ! same diamet]4 ,?is law also (t5 applies to ! developm5t ( l>ge prom95ces4 ,! co9cid5ce agrees well ) ! !ory t !re exi/s on ! ,sun "s action resembl+ t ( our tides4 ,:atev] may be ! am\nt ( probability :i* atta*es to ^! explanations we ought n to =get t we are /ill f> (f f possess+ ! p[] ( giv+ a vigor\s demon/ration ( !m4 ,if we consid] ) att5tion ! p]iodical v>iations ( ! spots we %all n be long 9 com+ to ! conclusion t x is impossible to connect !m directly ) any "o a/ronomical function 9 p>ticul>1 = ! spots appe> 9 a sudd5 & irregul> mann] :i* contra/s 9 a /rik+ degree ) ! cont9u\s & progressive action ( ! ord9>y p]turbations :i* we meet ) 9 ! /udy ( ,cele/ial ,me*anics4 ,!re is b "o reply possible to ?is objection4 ,! spots & _! *anges mu/ be visible manife/ations ( ! p]iodical activity ( ! ,sun--an activity :i* itself dep5ds 7z assum$7 on ! action ( ! planets & on _! relative positions4 ,! cause1 ?us def9$1 ( ! ,sun's activity may be v regul>2 ! activity itself may v>y 9 a cont9u\s mann] )\t ! result+ ph5om5a possess+ ! same cont9uity & ! same regul>ity4 ,we see ?is 9 ! p]iodical succession ( ! ,seasons on ! ,e>?4 ,! position ( ! ,sun1 & consequ5tly its mann] ( act+ ^u our globe1 v>ies ) a rem>kable uni=mity1 b nev]!less ! meteorological ph5om5a :i* result are irregul> & caprici\s4 ,?us x comes ab\t t physici/s are m & m incl9$ to believe t ! spots are only second>y effects produc$ by causes m important & m fundam5tal4 ,:atev] may be our ignorance z to ! causes :i* produce v>iations 9 ! ,sun's activity we may at lea/ draw "o conclusion f ! prec$+ rem>ks3 x is1 t ! ,sun is a v long way f hav+ arriv$ at a /ate ( tranquillity & fre$om f int]nal commotion4 ,on ! contr>y1 x is ! seat ( great movem5ts4 ,its activity is subject to numb]less p]iodical *anges :i* ought 9 _! turn to influ5ce ! int5sity ( ! heat & light giv5 out by ! ,sun2 & s re-act on ! planets :i* receive _! heat1 light1 & life f ! ,sun4 ,no acc\nt ( ! p]iodicity ( ! spots on ! ,sun c be deem$ complete :i* does n include in=mation respect+ c]ta9 o!r p]iodical ph5om5a :i* h be5 f\nd to exhibit features ( alt]nation closely resembl+ 9 _! sequ5ce & "* ! p]iodical *anges :i* take place 9 reg>d to ! spots on ! ,sun4 ,!re is evid5tly a deep my/]y ly+ hid "u ! curi\s fact 7:i* is cle>ly e/abli%$7 t ! #aa-ye> p]iod ( ! spots co9cides 9 a mann] z unexpect$ z x is c]ta9 ) ! p]iod ( ! v>iation ( t]re/rial magnetism4 ,! magnetic ne$le is subject to a diurnal v>iation :i* rea*es its extreme am\nt e #aa ye>s1 & n only s1 b ! epo* ( maximum v>iation corresponds ) ! epo* ( ! maximum preval5ce ( ,sun spots4 ,& simil>ly ye>s 9 :i* ! ne$le is lea/ di/urb$ are also ye>s 9 :i* ! ,sun spots are fewe/4 ,two o!r v curi\s discov]ies h also be5 made :i* are 9 evid5t close connection ) ! =ego+4 ,! manife/ation ( ! ,aurora ,borealis & ( ^? /range curr5ts ( electricity kn[n z magnetic e>? curr5ts 7:i* travel bel[ ! ,e>?'s surface & frequ5tly int]f]e ) telegraphic op]ations71 likewise exhibit p]iodical *anges :i* take #aa ye>s to g ?r\gh all _! /ages4 ,?is fact alone w\ld be suffici5tly curi\s1 b :5 we come to f9d t ! curve :i* exhibits ! *anges ^! two manife/ations ( =ce g ?r\gh1 also %[s t _! maxima & m9ima are contemporane\s ) ! maxima & m9ima ( ! ,sun spots & magnetic ne$le v>iations1 we _c d\bt t 7to use ,balf\r ,/ew>t's words7 8a bond ( union exi/s betwe5 ^! f\r ph5om5a4 ,! "q next arises1 :at is ! nature ( ?is bond8 ,n[1 ) respect to t :i* connects ,sun spots ) magnetic di/urbances we c z yet =m no conjecture40 ,to cut a long /ory %ort1 x may be said g5]ally t :il/ )\t d\bt electricity is ! common basis ( ! ?ree la/-nam$ ( ! f\r ph5om5a j m5tion$1 x seems sc>cely too great a /ret* ( ! imag9ation to g "o /ep fur!r & sugge/ t electricity has 9 "s or o!r occult mann] some?+ to d ) all ^! ?+s & !re=e ) ! spots on ! ,sun4 ,illu/ration3 ,fig4 #h4--,! ,sun totally eclips$1 ,july #ah1 #ahfj 7,feilitzs*74 ,! read] :o has foll[$ me ?us f> w by ?is "t be 9 a position to appreciate a rem>k made 9 an e>li] "p ( ?is *apt]1 t ! multitude ( facts kn[n to u 9 connection ) ! ,sun & its spots is s great1 z to r5d] x impossible to exhibit 9 a s+le *apt] any?+ m ?an ! b>e/ outl9e ( !m4 ,! num]\s obs]vations ( rec5t eclipses ( ! ,sun1 especially s9ce t ( #ahfj1 & ! ext5sive application ( ! spectroscope to ! ,sun bo? 9 connection ) ^! eclipses1 & g5]ally1 may be said to h completely revolutionis$ our k ( sol> ph5om5a dur+ ! pres5t g5]ation2 or p]haps x might be m correct to say h enorm\sly increas$ our k ( ! facts ( ! case & h revolutionis$ 9 no small degree ! conclusions d$uc$ f ! facts4 ,,*apt] ,,iii4 ,,m]cury4 ,s f> z we "k at pres5t1 ,m]cury is ! ne>e/ planet to ! ,sun4 ,! circum/ances "u :i* x pres5ts itself to u & a brief g5]al acc\nt ( its movem5ts h already be5 /at$4 ,9 ! pres5t *apt]1 !re=e 7& ?is rem>k applies 9 sub/ance to ea* ( ! succe$+ *apt]s appropriat$ to p>ticul> planets71 ,i %all limit myself to su* topics z seem to be ( int]e/ to an obs]v] arm$ ) a telescope4 ,m]cury1 z already m5tion$1 exhibits f "t to "t phases :i* may be said to be ! same z ^? ( ! moon2 b z ! only *ance ( see+ x is :5 x is at its greate/ di/ance ea/ or we/ ( ! ,sun1 practically x c only be /udi$ :5 91 or r ne> to1 :at may be call$ ! half-moon phase2 & ev5 !n obs]vations on its physical appe>ance c only be obta9$ ) difficulty4 ,p]haps its mo/ def9ite feature is its col\r4 ,?is1 und\bt$ly1 is m or less p9k4 ,/range to say1 9 spite ( ! multiplication ( telescopes & obs]v]s1 comp>atively little att5tion has be5 paid to ?is planet1 & we really "k v little m ab\t x ?an ,s*rt] told u ne>ly a hundr$ ye>s ago4 ,he obta9$ :at he conceiv$ to be satisfactory evid5ce ( ! exi/5ce ( at any rate "o m\nta91 hav+ a height ( ab\t #aa ,engli% miles--a height :i* x w be not$1 f> exce$s1 n only relatively b absolutely1 any m\nta9 on ! e>?4 ,:at ,s*rt] bas$ ?is conclusion ^u 0 ! fact t :5 ! planet 0 ne> inf]ior conjunction1 ! s\!rn horn pres5t$ a truncat$ appe>ance1 :i* might be ! result ( a l(ty projection arre/+ ! ,sun's light4 ,s*rt] also ann\nc$ t ,m]cury rotat$ on its axis 9 #bd h\rs #e m9utes4 ,sir ,w4 ,h]s*el fail$ to satisfy himself t ,s*rt]'s conclusions 7 well-f\nd$1 b x mu/ c]ta9ly be admitt$ t "s support = !m is furni%$ by c]ta9 obs]vations made )9 ! la/ few ye>s4 ,x is matt] = regret1 h[ev]1 t mo/ ( ^! 7 made ) in/rum5ts ( sizes :i*1 = ! mo/ "p1 _c be said to h be5 equal to ! task to :i* !y 7 appli$4 ,! truncature ( ! s\!rn horn fir/ spok5 ( by ,s*rt]1 0 ?\ght by ,d5n+1 9 #ahhb1 to be obvi\s2 & 9 ! same ye>1 by wat*+ ! displacem5t ( c]ta9 bright & dusky spaces on ! disc1 ! same obs]v] conclud$ t a rotation p]iod ( ab\t #be h\rs 0 indicat$4 ,9 #ahhb ,s*iap>elli at ,milan comm5c$ a prolong$ /udy ( ,m]cury4 ,believ+ t x 0 ess5tial to obs]ve ?r\gh a good condition ( atmosph]e1 & t ?is 0 impossible if ! planet 7 only look$ at 9 twilight1 :5 x 0 necess>ily at a l[ altitude1 ,s*iap>elli made all 8 obs]vations ) ! ,sun & planet high up 9 ! heav5s4 ,he consid]$1 9 effect1 t ! blaze ( ! ,sun's light 0 a less] evil ?an ! tremors insep>able f obs]vations ( ! planet1 cle> x might be 9 "s degree ( inconv5i5t ,sun-light1 b view$ ?r\gh ! vap\rs & atmosph]ic di/urbances1 :i* always spoil all obs]vations ne> ! horizon4 ,s*iap>elli's obs]vations yield$ v>i\s results1 mo/ ( !m novel1 & "o ( !m v />tl+4 ,he consid]s ,m]cury to be a mu* spott$ globe & to be envelop$ 9 a tol]ably d5se atmosph]e4 ,he ?\ght he notic$ br[ni% /ripes & /reaks 7:i* might be reg>d$ z p]man5t m>k+s71 m cle>ly visible on "s occasions ?an on o!rs2 & t ^! sy/ematically disappe>$ ne> ! limb1 ow+ to ! increas$ dep? !re ( ! atmosph]e ?r\gh :i* !y _h to be look$ at4 ,! =ego+ obs]vations may be reg>d$ z n unreasonable2 !y may ev5 be accept$ )\t fur!r "q4 ,b :at are we to say to ,s*iap>elli's conclusions t ^! m>k+s are s ne>ly p]man5t1 tak+ "o day ) ano!r1 t ,m]cury's rotation _c be measur$ 9 h\rs at all1 b is a matt] ( days1--9 po9t ( fact1 ( #hh days2 & t 9 reality ,m]cury occupies 9 its rotation on its axis ! :ole ( ! #hh days :i* con/itute its sid]eal ye>1 or p]iod ( revolution r\nd ! ,sun4 ,! c\nt]p>t ( ?is = u w\ld be t1 in/ead ( ! inhabitants ( ! e>? hav+ a day ( #bd h\rs1 !y w\ld h only "o day & night e #cfe days4 ,a/ronom]s are n at pres5t satisfi$ to accept ?is conclusion 9 reg>d to ,m]cury4 ,"s obs]v]s h ?\ght t ,m]cury is m easy to obs]ve ?an ,v5us1 & t1 speak+ g5]ally1 its surface1 if we c\ld only get to see x con/antly "u fav\rable circum/ances1 might be consid]$ to resemble 9 mo/ respects t ( ,m>s4 ,m]cury revolves r\nd ! ,sun at a mean di/ance ( #cf millions ( miles4 ,ow+1 h[ev]1 to ! fact t ! ecc5tricity ( its orbit 7or its dep>ture f ! circul> =m7 is great] ?an t ( any ( ! o!r major planets1 x may approa* to )9 #bh millions ( miles or rec$e to m ?an #dc millions ( miles4 ,its app>5t diamet] v>ies betwe5 #d 9 sup]ior conjunction to #ac 9 inf]ior conjunction4 ,! real diamet] may be tak5 at ab\t #cjjj miles4 ,,*apt] ,,iv4 ,,v5us4 ,! planet ,v5us has two ?+s 9 common ) ,m]cury4 ,"o is1 t be+ an inf]ior planet1 t is to say1 a planet revolv+ r\nd ! ,sun 9 an orbit )9 t ( ! ,e>?1 x is nev] v f> di/ant f ! ,sun1 & !re=e c nev] be se5 on a di/9ctly d>k sky4 ,! second po9t allud$ to arises out ( ! fir/2 ,v5us exhibits f "t to "t a s]ies ( phases :i* are id5tical 9 "* ) ^? ( ,m]cury1 & !re=e ) ^? ( ! ,moon4 ,v5us diff]s1 h[ev]1 f ,m]cury 9 ! v important po9t ( size4 ,inasmu* z its diamet] is consid]ably m ?an d\ble ! diamet] ( ,m]cury x has a surface m ?an six times z great1 & !re=e exhibits a f> l>g] area ( illum9ation ?an ,m]cury does4 ,! result ( ?is 7c\pl$ ) ano!r fact :i* w be /at$ pres5tly7 is t ! planet may (t5 be easily se5 9 broad daylight1 & sometimes ca/s a s5sible %ad[ at night4 ,"u special circum/ances1 :i* recur e #h ye>s1 ?is planet %9es ) v peculi> brilliancy4 ,true1 t only ab\t ? ( ! :ole disc is !n illum9at$1 b t fraction transmits to u m light ?an phases ( great] ext5t d1 because ^! latt] co9cide ) epo*s :5 ! planet is m remote f ! ,e>?4 ,spots & %ad+s h on v>i\s occasions be5 notic$ on ,v5us1 & ?\gh x is n easy to h>monise ! v>i\s acc\nts1 !re seems no d\bt ( ! reality ( ! facts1 or t !y mu/ be ascrib$ to ! exi/5ce ( m\nta9s4 ,s*rt] f\nd v mu* ! same /ate ( ?+s to exi/ on ,v5us t he f\nd on ,m]cury1 & putt+ toge!r :at he saw he arriv$ at ! conclusion t ,v5us possesses m\nta9s ( consid]able height1 & t 8 obs]vations mu/ be tak5 to imply t ! planet revolv$ on its axis 9 r m ?an #bc h\rs4 ,?is conclusion z reg>ds ! planet's axial rotation 0 n fir/ arriv$ at by ,s*rt]1 = ! two ,cass9is1 "o ab\t #afff1 & ! o!r ab\t #agdj1 bo? ascrib$ to ,v5us a rotation p]iod ( ab\t #bc h\rs1 an evaluation :i* 0 fully confirm$ by ,di ,vico at ,rome betwe5 #ahci & #ahda1 & by ,flamm>ion 9 #ahid4 ,:at has be5 already said ) respect to ,m]cury is true also ( ,v5us1 namely t x has be5 mu* neglect$ by mod]n obs]v]s2 & accord+ly an ann\ncem5t made by ,s*iap>elli 9 #ahij1 t ! rotation p]iod ( ,v5us is to be measur$ n by h\rs b by mon?s1 came ^u ! a/ronomical _w z a />tl+ revelation2 b x is a revelation :i* has be5 ke5ly conte/$1 & c]ta9ly awaits legal pro(4 ,s*iap>elli has n v5tur$ to ass]t z he has done 9 ! case ( ,m]cury1 t ,v5us's rotation p]iod is id5tical ) ! p]iod ( #g mon?s 9 :i* x revolves r\nd ! ,sun2 he only claims ?is z a /rong probability aris+ out ( :at he says he is c]ta9 (1 namely t its p]iod ( rotation _c be less ?an six mon?s & may be z mu* z n9e mon?s4 ,8 assumption is t previ\s obs]v]s 9 endeav\r+ to asc]ta9 ,v5us's rotation p]iod h us$ & reli$ ^u evanesc5t %ad+s :i* probably 7 ( atmosph]ic orig9 & sc>cely recognisable f day to day1 :]eas he fix$ 8 att5tion ^u r\nd def9$ :ite spots1 :i*1 :atev] _! orig91 are s f> p]man5t t _! exi/5ce has be5 spok5 ( = two c5turies4 ,miss ,cl>ke ?us puts ! matt]3--8,8 /eady wat* ov] !m %[$ ! inv>iability ( _! position ) reg>d to ! t]m9ator2 & ?is is z mu* z to say t ! regions ( day & night d n %ift on ! surface ( ! planet4 ,9 o!r words %e keeps ! same face always turn$ t[>ds ! ,sun40 ,v>i\s rec5t obs]vations1 "s ( !m made ) ! express object ( ?r[+ light ^u ,s*iap>elli's conclusions1 are /rangely contradictory4 ,p]rot9 at ,nice 9 #ahij ?\ght 8 obs]vations confirm$ ,s*iap>elli's2 on ! o!r h& ,nie/5 at ,brussels consid]$ t num]\s draw+s ( ,v5us made by himself & ,/uyva]t betwe5 #ahha & #ahij h>monis$ well ) ,di ,vico's rotation p]iod ( #bc;h4 #bam4 #bbs42 :i* ,tr\velot 9 #ahib only wi%$ to increase to ab\t #bd h\rs4 ,!re is a g5]al cons5sus ( op9ion t great irregul>ities exi/ on ! surface ( ,v5us4 ,^! are made specially manife/ to u 9 connection ) ! t]m9ator or visible edge ( ! planet se5 z an illum9at$ cresc5t4 ,if ! planet _h a smoo? surface ?is l9e w\ld at all times be a p]fect & cont9u\s curve1 in/ead ( :i* x is frequ5tly to be notic$ z a jagg$ or brok5 l9e4 ,obs]vations to ?is effect g back z f> z #afdc1 :5 ,fontana at ,naples obs]v$ ?is to be ! condition ( ! t]m9ator4 ,la ,hire1 ,s*rt]1 ,mdl]1 ,di ,vico & _m o!rs d[n to ! pres5t epo* h not$ ! same ?+4 ,! fact t ! s\!rn horn ( ,v5us is con/antly to be se5 blunt$ is s well e/abli%$ z to admit ( no d\bt1 & ?is blunt+ is commonly ascrib$ to ! exi/5ce ( a l(ty m\nta91 to :i* ,s*rt] ascrib$ a height ( #bg miles4 ,:atev] we may ?9k z to ! precise accuracy ( ?is figure1 x seems impossible to d\bt ! ma9 fact on :i* x dep5ds2 :il/ a ,belgian obs]v]1 ,van ,ertborn1 9 #ahgf repeat$ly saw a po9t ( light 9 ?is locality :i* he reg>d$ z due to ,sun-light imp++ on a deta*$ peak1 adjac5t valleys rema9+ 9 %ad[4 ,?is effect is common en\gh 9 ! case ( ! ,moon1 & is famili> to all :o are 9 ! habit ( /udy+ ! ,moon4 ,illu/ration3 ,fig4 #i4--,v5us1 ,dec4 #bc1 #ahhe4 ,! exi/5ce on ,v5us ( an atmosph]e ( consid]able d5sity & ext5t is well e/abli%$4 ,pro( ( ?is is to be f\nd 9 ! m>k$ dim9ution ( ! planet's brilliancy t[>ds ! t]m9ator2 & 9 ! fa9t curv$ l9e ( light :i* occasionally may be se5 :5 ! planet is ne> inf]ior conjunction4 ,:5 s situat$1 s mu* ( ! planet itself z c be se5 illum9at$ %[s z a n>r[ radiant cresc5t ( light1 end+ (f 9 two po9ts call$ indiff]5tly cusps or horns4 ,x sometimes happ5s1 h[ev]1 t f ! po9t ( ea* cusp !re runs r\nd to ! o!r cusp a fa9t cont9uation ( ! cresc5t1 result+ 9 ! g5]al appe>ance ( ! planet be+ t ( a ne>ly uni=m r+ ( light4 ,!re is no kn[n way 9 :i* ! ,sun c illum9ate s mu* m ?an ! half ( ,v5us s z to p]mit ( a p]fect circle be+ visible except by suppos+ t an atmosph]e exi/s on ! planet & refracts 7or transmits by b5d+1 z x 71 r\nd ! corn]7 a suffici5t am\nt ( ,sun-light to give rise to ! appe>ance 9 "q4 ,fur!r pro( ( ! exi/5ce ( an atmosph]e on ,v5us is obta9able on ^? v r>e occasions :5 ! planet is se5 pass+ across ! disc ( ! ,sun--a ph5om5on kn[n z a 8,transit ( ,v5us40 ,x !n ne>ly always happ5s t a hazy nebul\s r+ ( feeble light may be detect$ encompass+ ! planet's disc indicative ( c\rse ( ! fact t ! ,sun's rays are !re slightly ob/ruct$ 9 rea*+ ! eye ( an obs]v] on ! ,e>?4 ,"s obs]v]s scrut9is+ ,v5us :5 9 transit h ?\ght t !y 7 able to obta91 by means ( ! spectroscope1 traces ( aque\s vap\r on ! planet1 b ! evid5ce ( ?is does n appe> to be altoge!r cle> or conclusive4 ,illu/ration3 ,fig4 #aj4--,v5us ne> conjunction z a ?9 cresc5t1 ,sept4 #ba1 #ahhg 7,flamm>ion74 ,ev]ybody may be presum$ to be acqua9t$ ) ! spectacle popul>ly kn[n z 8,! ,old ,moon 9 ! ,new ,moon's ,arms0 :]eby :5 ! ,moon is only ab\t two or ?ree days old & exhibits b a n>r[ cresc5t ( bright light1 yet ! :ole outl9e ( ! disc is traceable on ! sky4 ,a ph5om5on analog\s to ?is may (t5 be se5 9 ! case ( ,v5us :5 ne> its inf]ior conjunction4 ,) ! ,moon ! cause is due to ! reflection ( ,e>?-light 7s to speak7 to ! ,moon1 b t explanation seems inadequate 9 respect ( ,v5us1 because x is conceiv$ t ! am\nt ( ,e>?-light available is altoge!r insuffici5t = ! purpose4 ,_m o!r explanations h be5 put =w>d includ+ phosphoresc5ce on ! surface ( ,v5us1 electrical displays 9 ! nature ( t]re/rial auror1 & :at n1 b x mu/ be frankly confess$ t a/ronom]s are all at sea on ! subject4 ,! exi/5ce ( sn[ at ! poles ( ,v5us has be5 suspect$ by obs]v]s ( tri$ skill & exp]i5ce su* z ,phillips & ,webb1 ?\gh ! idea 0 fir/ broa*$ by ,grui?uis5 9 #ahac4 ,flamm>ion's obs]vations dur+ #ahib & ! two foll[+ ye>s are di/9ctly confirmatory ( ?is idea4 ,he adds t z bo? pol> caps are visible at ! same "t ! planet's axis _c be mu* incl9$ to ! plane ( its orbit4 ,comp>$ ) all ! o!r planets ! absolute brightness ( ,v5us /&s v high4 ,( c\rse x mu/ be und]/ood t by ?is phrase 8absolute brightness0 no m is meant ?an its reflective p[]4 ,v5us is :at x is by virtue ( its p[] ( reflect+ ,sun-light2 presumably x has no inh]5t brightness ( its own4 ,:at its reflective p[] is 0 probably nev] m effectively br\ght "u ! notice ( a human eye ?an on ,septemb] #bf1 #ahgh1 :5 ,nasmy? enjoy$ an opportunity ( see+ ,v5us & ,m]cury side by side = sev]al h\rs 9 ! same field ( view4 ,he speaks ( ,v5us z resembl+ clean silv] & ,m]cury z no?+ bett] ?an lead or z9c4 ,see+ t ow+ to its great] proximity to ! ,sun ! light incid5t on ,m]cury mu/ be "s #c times z /rong z ! light incid5t on ,v5us1 x foll[s t ! reflective p[] ( ,v5us mu/ be v great4 ,z a matt] ( fact x has be5 calculat$ to be ne>ly equal to newly fall5 sn[2 9 o!r words to reflect fully #gj p] c5t4 ( ! light :i* imp+es on x4 ,v5us has no satellite2 ?is fact seems c]ta94 ,yet half a doz5 or m obs]v]s betwe5 #afde & #agfh discov]$ su* a satellite2 obs]v$ x2 foll[$ x6 ,?is />tl+ my/]y1 z x really 01 attract$ "s ye>s ago ! att5tion ( a v c>eful ,belgian obs]v]1 ,/roobant1 :o exam9$ 9 a mo/ pa9/ak+ mann] all ! record$ obs]vations4 ,8 conclusions 7 t 9 almo/ all cases p>ticul> />s 7:i* he id5tifi$7 7 mi/ak5 = a satellite4 ,:]e ! object se5 0 n capable ( id5tification1 possibly x 0 a m9or planet2 :il/ 9 "o in/ance x 0 probable t x 0 ,uranus :i* _h be5 se5 & reg>d$ z a satellite ( ,v5us4 ,v5us is p]haps ! planet :i* has mo/ impress$ ! popul> m9d4 ,= ! e>lie/ illu/ration ( ?is /atem5t we mu/ g z f> back z ,hom] :o makes two ref]5ces to x 9 ! ,iliad4 ,^!1 9 ,pope's v]sion1 run z foll[s3-- 8,z radiant ,hesp] %9es ) ke5] light1 ,f> beam+ o'er ! silv] ho/ ( night40 --xxii4 #cii #cah4 8,! morn+ planet told ?' approa* ( light2 ,& fa/ beh9d1 ,aurora's w>m] ray ,o'er ! broad ocean p\r'd ! gold5 day40 --xxiii4 #bha #bbf4 ,! phases ( ,v5us 7 fir/ discov]$ by ,galileo & 7 made kn[n to ! _w1 or r to ,kepl]1 9 a my/ic s5t5ce :i* has (t5 be5 quot$3-- 8,hc immatura1 a me jam fru/ra leguntur--oy40 8,^! ?+s n ripe2 at pres5t read 9 va9 by o!rs are read by me40 ,! =m] s5t5ce transpos$ becomes-- ,cyn?i figuras mulatur mat] amorum4 ,! "m ( loves ,v5us imitates ! phases ( ,cyn?ia ! ,moon4 ,v5us revolves r\nd ! ,sun 9 #bbd days at a mean di/ance ( ab\t #fg millions ( miles4 ,its app>5t diamet] v>ies betwe5 #i 9 sup]ior conjunction1 & #fb 9 inf]ior conjunction4 ,! real diamet] is ab\t #gejj miles2 9 o!r words ,v5us is ne>ly z l>ge z ! ,e>?4 ,,*apt] ,v4 ,,! ,,e>?4 ,to u1 z its inhabitants1 ! ,e>? appeals 9 two *>act]s1 & 9 writ+ a book on a/ronomy x is necess>y1 yet difficult1 to keep ^! two *>act]s sep>ate4 ,! ,e>? is an ord9>y planet memb] ( ! sol> sy/em1 am5able to ! same laws1 impell$ by ! same =ces1 & go+ ?r\gh ! same movem5ts z ! o!r memb]s ( ! ,sun's ent\rage4 ,yet1 by reason ( ! fact t we are ourselves on ! ,e>? & are n spectators ( x look+ at x f at a di/ance1 !re are _m ph5om5a com+ "u our notice :i* require special treatm5t1 & x is (t5 v difficult to say :]e ! prov9ce ( ! a/ronom] ends & t ( ! geograph] beg9s4 ,?is volume be+ specially design$ to deal ) a/ronomical matt]s1 ,i %all pass ov] _m subjects :i* may be said to be on ! bord] l9e1 & :i* "s ( my read]s may !re=e be disappo9t$ n to f9d discuss$4 ,besides ! geograph]1 ! geologi/ & 8 sci5tific bro!r ! m9]alogi/ are conc]n$ ) ! ,e>? reg>d$ z a planet mov+ ?r\gh space z ! o!r planets d4 ,! geologi/ /udies ! actual /ructure ( ! ,e>?1 its circum/ances & hi/ory s f> z !y h be5 reveal$ to u1 :il/ ! m9]alogi/ inve/igates & names ! mat]ials ( :i* x is compos$1 & classifies su* mat]ials ) ! assi/ance ( ! geologi/ on ! "o h& & ( ! *emi/ on ! o!r4 ,all ^! subord9ate sci5ces--subord9ate ,i mean f an a/ronom]'s po9t ( view--op5 up v v>i$1 in/ructive1 & int]e/+ fields ( /udy1 b !y are ( c\rse =eign to ! purpose ( ! pres5t volume4 ,?\gh ! ,e>? is commonly reg>d$ z a sph]e x is n t 9 reality1 because x is n ( id5tical dim5sions f ea/ to we/ & f nor? to s\?4 ,x is some:at flatt5$ at ! poles2 its pol> diamet] is less ?an its equatorial diamet]1 9 ! ratio ( ab\t #bih to #bii1 or1 express$ 9 miles1 its pol> diamet] is ab\t #bf miles less ?an its equatorial diamet]4 ,if a globe #c feet 9 diamet] be tak5 to repres5t ! ,e>?1 !n ! pol> diamet] w1 on ?is scale1 be in* too long4 ,?is flatt5+ ( ! poles ( ! ,e>? f9ds its c\nt]p>t1 s f> z we "k1 9 mo/1 & probably 9 all ( ! planets4 ,x is mo/ consid]able & !re=e mo/ conspicu\s 9 ! case ( ,jupit]4 ,x ought "h to be add$ t a suspicion exi/s t ! equatorial section ( ! ,e>? is n a p]fect circle1 b t ! diamet] ( ! ,e>?1 tak5 ?r\gh ! po9ts on ! equator m>k$ by ! m]idians #ac #eh & #aic #eh ea/ ( ,gre5wi*1 is "o mile long] ?an ! diamet] at "r angles to ^! two po9ts4 ,! sci5ce :i* inquires into matt]s ( ?is k9d1 includ+ besides ! figure ( ! ,e>?1 ! l5g? ( ! degree at diff]5t latitudes1 & ! di/ances ( places f "o ano!r1 alike 9 angul> measure & 9 "t1 is call$ ,geodesy2 x is1 9 po9t ( fact1 l&-survey+ on a v l>ge scale1 9 :i* in/rum5ts & processes ( a/ronomical orig9 are br\ght into op]ation1 & 9 :i* a/ronom]s are m or less requir$ to take ! lead4 ,al?\gh we all ( u n[ p]fectly und]/& t ! ,e>? is a planet mov+ r\nd ! ,sun z a c5tre1 x is1 comp>atively speak+1 b rec5tly t ?is fact has become g5]ally recognis$ & und]/ood4 ,x is true t we c discov] "h & !re 9 anci5t writ+s "s trace ( ! idea1 yet x is d\btful :e!r #bjjj ye>s ago m ?an a few 8advanc$0 ?9k]s ?or\ghly & cle>ly accept$ x z a di/9ct tru?4 ,x 0 mu* m 9 consonance ) popul> ?\ght & ! actual appe>ance ( ?+s t ! ,e>? %\ld be ! c5tre r\nd :i* ! ,sun revolv$ & on :i* ! planets dep5d$2 & accord+ly1 sometimes 9 "o %ape & sometimes 9 ano!r1 ! notion ( ! ,e>? be+ ! c5tre ( ! univ]se 0 g5]ally accept$4 ,! contr>y op9ion _h1 h[ev]1 a few sympa?is]s4 ,= in/ance1 ,ari/>*us ( ,samos1 :o liv$ 9 ! ?ird c5tury be=e ! ,*ri/ian era1 suppos$1 if we may tru/ ! te/imony ( ,ar*im$es & ,plut>*1 t ! ,e>? revolv$ r\nd ! ,sun2 ?is1 h[ev]1 0 reg>d$ z a 8h]esy10 9 respect ( :i* he 0 accus$ ( 8impiety40 ,"s few ye>s elaps$ & a c]ta9 ,clean!s ( ,assos is said by ,plut>* to h sugge/$ t ! great ph5om5a ( ! univ]se might be expla9$ by assum+ t ! ,e>? 0 endu$ ) a motion ( translation r\nd ! ,sun toge!r ) "o ( rotation on its own axis4 ,! hi/orian /ates t ?is idea 0 s contr>y to ! receiv$ op9ions t x 0 propos$ to put ,clean!s on 8 trial = impiety4 ,9 =m] times ! philosoph]s :o /udi$ ! sol> sy/em rang$ !mselves 9 sev]al 8s*ools ( ?\ght10 to use a mod]n hackney$ phrase4 ,"s upheld ! ,ptolemaic sy/em1 :i* took its "n f a great ,egyptian a/ronom]1 ,claudius ,ptolemy1 ?\gh x does n appe> t he 0 actually ! fir/ to sugge/ x4 ,! ,ptolemaic sy/em reg>d$ ! ,e>? z ! c5tre1 ) ! foll[+ bodies1 all call$ planets1 revolv+ r\nd x 9 ! ord] /at$3--! ,moon1 ,m]cury1 ,v5us1 ! ,sun1 ,m>s1 ,jupit]1 & ,saturn4 ,x w be obs]v$ t !re are sev5 bodies "h nam$1 & z sev5 0 reg>d$ z ! 8numb] ( p]fection10 x 0 9 lat] times consid]$ t only ^! sev5 bodies 7nei!r m nor less7 c\ld really be ! ,e>?'s cele/ial att5dants4 ,?\gh ,ptolemy 0 9 "o s5se an ,egyptian1 !re yet prevail$ among/ ! ,egyptians at l>ge ano!r !ory slightly diff]5t f ,ptolemy's4 ,accord+ to ! 8,egyptian !ory10 ,m]cury & ,v5us 7 reg>d$ z satellites ( ! ,sun1 & n z prim>y planets appurt5ant to ! ,e>?4 ,aft] ,ptolemy's era _m c5turies elaps$1 dur+ :i* ! :ole subject ( ! sol> sy/em lay practically dormant1 & x cont9u$ s until ! revival ( le>n+ br\ght new !ori/s ^u ! sc5e4 ,! mo/ important ( ^! 0 ,cop]nicus1 :o1 9 ! sixte5? c5tury1 prop\nd$ a !ory :i* ev5tually sup]s$$ all o!rs1 &1 ) slight modifications1 is ! "o n[ accept$4 ,cop]nicus plac$ ! ,sun 9 ! c5tre ( ! sy/em1 & treat$ x z ! po9t ar\nd :i* all ! prim>y planets revolv$4 ,s f>1 s good2 b ,cop]nicus w5t a/ray on ! "q ( ! orbits ( ! planets4 ,he fail$ to realise ! true "* ( ! curves :i* !y foll[ & treat$ ^! curves z 8epicycles10 :i* ^w may be describ$ z repres5t+ a complicat$ comb9ation ( little circles :i* tak5 toge!r =m a big "o4 ,x 0 left to ,kepl] & ,newton to settle all su* details on a true & firm basis4 ,b be=e ?is /age 0 rea*$ a man ( ! highe/ a/ronomical atta9m5ts & practical exp]i5ce1 ,ty*o ,brahe1 made %ipwreck ( 8 reputation z an a/ronom] by solemnly reviv+ ! idea ( ! ,e>? be+ ! immovable c5tre ( ev]y?+4 ,he treat$ ! ,moon z revolv+ r\nd ! ,e>? at no great di/ance & ! ,sun z do+ ! same ?+ a little f>!r (f2 ! five planets revolv+ r\nd ! sun z sol> satellites4 ,! 8,ty*onic sy/em10 z x is call$1 has some?+ 9 common ) ! ,ptolemaic sy/em )\t be+ by any means z logical z ! latt]4 ,t su* f>-fet*$ ideas z ,ty*o's %\ld h be5 palm$ (f on ! _w ( sci5ce s rec5tly z #cjj ye>s ago is pass+ /range2 b ! explanation appe>s to be t 8 action arose out ( a misconception ( c]ta9 passages ( ,holy ,scripture1 :i* seem$ irreconcilable ) ! ,cop]nican !ory4 ,x mu/ n be =gott5 t ,cop]nicus's fam\s book1 publi%$ 9 #aedc1 9 :i* he _h ann\nc$ 8 views1 _h be5 condemn$ by ! ,papal 8,congregation ( ! ,index20 & !re=e ,ty*o might h _h z a fur!r motive a desire to curry fav\r ) ! au?orities ( ! ,*ur* ( ,rome1 & to gratify 8 own vanity at ! same "t4 ,) ^! explanations x w no long] be mislead+ if1 = conv5i5ce sake1 ,i speak ( a c]ta9 great circle ( ! heav5s z app>5tly trav]s$ by ! ,sun e ye>1 ow+ to ! revolution ( our ,e>? r\nd t body4 ,?is circle is call$ ! 8,ecliptic10 & its plane is usually employ$ by a/ronom]s z a fix$ plane ( ref]5ce4 ,x mu/ be di/+ui%$ f t o!r great circle call$ ! 8cele/ial equator10 :i* is ! plane ( ! ,e>?'s equator ext5d$ t[>ds ! />s4 ,! plane ( ! equator is incl9$ to ! ecliptic at an angle ( ab\t #bc1 :i* angle is kn[n z ! 8obliquity ( ! ecliptic40 ,x is ?is incl9ation :i* gives rise to ! seasons :i* foll[ "o ano!r 9 succession dur+ our annual j\rney r\nd ! ,sun4 ,! two po9ts :]e ! cele/ial equator & ! ecliptic int]sect are call$ ! 8equ9oxes10 ( spr+ or autumn z ! case may be2 ! po9ts midway betwe5 ^! be+ ! 8sol/ices10 ( summ] or w9t] z ! case may be4 ,^! words ne$ b little explanation1 at any rate1 z reg>ds ^? p]sons :o are able to trace ! ,lat9 orig9 ( ! words4 8,equ9ox0 is simply ! place occupi$ by ! ,sun twice e ye> 7namely ab\t ,m>* #bj & ,septemb] #bb71 :5 day & night are !oretically equal ?r\gh\t ! _w1 :5 also ! sun rises exactly 9 ! ea/ & sets exactly 9 ! we/4 ,! 8sol/ices0 repres5t ! /&+ /ill ( ! sun at ! giv5 times & places1 & are ! neutral po9ts :]e ! ,sun atta9s its greate/ nor!rn or s\!rn decl9ation4 ,?is usually occurs ab\t ,june #ba & ,decemb] #ba4 ,x mu/ n be =gott5 by ! way1 t ! above application ( ! words 8summ]0 & 8w9t]0 to ! sol/ices is only correct s f> z conc]ns places 9 nor!rn t]re/rial latitudes--,europe & ! ,unit$ ,/ates1 = in/ance4 ,9 s\!rn t]re/rial latitudes--= in/ance1 :5 speak+ ( :at happ5s at ! ,cape ( ,good ,hope & 9 ,au/ralia--! words mu/ be rev]s$4 ,we h se5 9 a previ\s *apt] t :il/ ! orbits ( ! planets are ne>ly true circles1 none ( !m are q su*3 & ! dep>ture f ! truly circul> =m results 9 "s important consequ5ces4 ,:il/ "s ( ^! are too te*nical to be expla9$ 9 detail "h1 "o at lea/ mu/ be ref]r$ to because ( :at x involves4 ,n only is ! ,e>?'s orbit ecc5tric 9 =m1 b its ecc5tricity v>ies )9 n>r[ limits2 & besides ?is ! orbit itself1 z a :ole1 is subject to a p]iodical %ift ( place1 f ! jo9t effect ( all :i* *anges x comes ab\t t our seasons are n[ ( unequal l5g?1 ! spr+ & summ] qu>t]s ( ! ye> unit$ly ext5d+ to #ahf days1 :il/ ! autumn & w9t] qu>t]s comprise only #agh days4 ,! sun !re=e has ! *ance ( %9+ = a long] absolute p]iod ( "t ov] ! nor!rn hemisph]e ?an ov] ! s\!rn hemisph]e2 h5ce ! nor!rn is ! w>m] ( ! two hemisph]es1 because x has a bett]1 because a long]1 *ance ( /or+ up an accumulation ( sol> radiant heat4 ,probably x is "o result ( ?is t ! nor? pol> regions ( ! ,e>? are easi] ( access ?an ! s\? pol> regions4 ,9 ! nor!rn hemisph]e navigators h rea*$ to #ha ( latitude1 :]eas #ga is ! highe/ limit yet atta9$ 9 ! s\!rn hemisph]e4 ,read]s :o h /udi$ ! hi/ory ( explorations 9 ! ,arctic regions w n ne$ to be rem9d$ ( ! controv]sy :i* has s (t5 aris5 respect+ ! exi/5ce or nonexi/5ce ( an 8,op5 ,pol> ,sea40 ,x has already be5 h9t$ t x is n an easy matt] to det]m9e1 :5 deal+ ) ! ,e>?1 :]e a/ronomy & its alli$ sci5ces1 geography1 geodesy & geology respectively1 beg9 & end4 ,b z c]ta9 topics connect$ ) ^! sci5ces1 su* z ! rotundity ( ! ,e>? & its rotation on its axis1 w come m conv5i5tly "u consid]ation 9 o!r volumes ( ?is s]ies1 ,i %all pass !m ov] & only treat ( a few ?+s :i* m directly conc]n ! /ud5t ( nature obs]v+ ei!r ) or )\t ! assi/ance ( a telescope4 ,! fact t ! ,e>? is surr\nd$ by a consid]able atmosph]e l>gely compos$ ( aque\s vap\r has a mat]ial be>+ on ! success or failure ( obs]vations made on ! ,e>? ( bodies situat$ at a di/ance4 ,x may be tak5 z a g5]al rule t ! ne>] an obs]v] is to ! surface ( ! sea1 or o!rwise to ! surface ( ! l& at ! sea-level1 ! great] w be ! difficulty :i* w confront him 9 c>ry+ on a/ronomical obs]vations4 ,h5ce su* obs]vations are g5]ally made ) unsatisfactory results on ! sea coa/ or on ! banks ( riv]s4 ,an int]e/+ b r anci5t illu/ration ( ?is la/-nam$ fact is to be f\nd 9 ! circum/ance t ,cop]nicus1 :o di$ at ! age ( #gj1 compla9$ 9 8 la/ mom5ts t mu* z he _h tri$ he _h nev] succe$$ 9 detect+ ! planet ,m]cury1 a failure due1 z ,gass5di suppos$1 to ! vap\rs prevail+ ne> ! horizon at ! t[n ( ,?orn on ! banks ( ! ,vi/ula :]e ! illu/ri\s philosoph] liv$4 ,! ph5om5a dep5d+ on ! pres5ce ( aque\s vap\r 9 ! atmosph]e :i* especially "u ! notice ( ! a/ronom] are ,refraction1 ,twilight1 & ! ,tw9kl+ ( ! ,/>s4 ,refraction is :at x pr(esses to be1 a b5d+1 & :at is b5t is ! ray ( light com+ f a cele/ial object to a t]re/rial /ation4 ,olm/$ has put ! matt] 9 ?is way3--8,we mu/ consid] t any su* object always appe>s 9 ! direction 9 :i* ! la/ ray ( light comes to ! eye4 ,if ! light :i* comes f a /> 7 b5t into fifty directions be=e x rea*$ ! eye1 ! /> w\ld nev]!less appe> 9 a l9e describ$ by ! ray ne>e/ ! eye4 ,! op]ation ( ?is pr9ciple is se5 :5 an o>1 or any /ick1 is ?ru/ into ! wat]4 ,z ! rays ( light by :i* ! o> is se5 h _! direction *ang$ z !y pass out ( wat] into air1 ! app>5t direction 9 :i* ! body is se5 is *ang$ 9 ! same degree1 giv+ x a b5t appe>ance--! "p bel[ ! wat] hav+ app>5tly a diff]5t direction f ! "p above40 ,! direction ( ?is refraction is det]m9$ by ! g5]al law ( optics t :5 a ray ( light passes out ( a r>] into a d5s] m$ium 7= in/ance out ( air into wat]1 or out ( space into ! ,e>?'s atmosph]e7 x is b5t t[>ds a p]p5dicul> to ! surface ( ! m$ium2 b :5 x passes out ( a d5s] into a r>] m$ium x is b5t f ! p]p5dicul>4 ,! effect ( refraction is to make a heav5ly body appe> to h an app>5t altitude great] ?an its true altitude1 s t1 = example1 an object situat$ actually 9 ! horizon w appe> above x4 ,inde$ x sometimes happ5s t objects :i* are actually bel[ ! horizon & :i* o!rwise w\ld be invisible 7 x n = refraction are ?us br\ght into sight4 ,x 0 9 consequ5ce ( ?is t on ,april #bj1 #ahcg1 ! ,moon rose eclips$ be=e ! ,sun _h set4 ,sir ,h5ry ,holl& ?us alludes to ! ph5om5on3--8,i am tempt$ to notice a spectacle1 hav+ a c]ta9 association ) ?is sci5ce1 :i* ,i d n rememb] to h se5 record$ ei!r 9 prose or poetry1 ?\gh well m]it+ description 9 ei!r way4 ,?is spectacle requires1 h[ev]1 a comb9ation ( circum/ances r>ely occurr+--a p]fectly cle> ,ea/]n & ,we/]n horizon1 & an entirely level int]v5+ surface1 su* z t ( ! sea or ! ,african des]t--! =m] r5d]+ ! illusion1 if su* x may be call$1 mo/ complete to ! eye4 ,! view ,i seek to describe embraces ! orb ( ! sett+ ,sun1 & t ( ! full ,moon ris+ 9 ! ,ea/--bo? above ! horizon at ! same "t4 ,! spectator on ! sea betwe51 if he c disc>d f m5tal vision ! vessel on :i* he /&s1 & reg>d only ^! two great globes ( ,heav5 & ! sea-horizon circl+ unbrok5 ar\nd him1 ga9s a conception ?r\gh ?is spectacle cle>] ?an any o!r conjunction c give1 ( ^? wond]ful relations :i* x is ! triumph ( a/ronomy to disclose4 ,all objects are exclud$ save ! ,sun1 ! ,moon1 & our own ,globe betwe51 b ^! objects are su* 9 !mselves t _! v simplicity & paucity ( numb] enhances ! s5se ( ! sublime4 ,only twice or ?rice1 h[ev]1 h ,i witness$ ! sight 9 its complet5ess--once on a ,m$it]ranean voyage betwe5 ,m9orca & ,s>d9ia--once 9 cross+ ! des]t f ,suez to ,cairo1 :5 ! same full ,moon %[$ me1 a few h\rs lat]1 ! v diff]5t b picturesque sight ( "o ( ! annual c>avans ( ,mecca pilgrims1 ) a long tra9 ( camels mak+ _! night m>* t[>ds ! ,r$ ,sea40#c ,x is due to ! same cause t ! ,sun & ! ,moon :5 v ne> ! horizon may (t5 be notic$ to exhibit a di/ort$ oval outl9e4 ,! fact simply is1 t ! upp] & ! l[] limbs und]go a diff]5t degree ( refraction4 ,! l[] limb be+ ne>] ! horizon is m affect$ & is consequ5tly rais$ to a great] ext5t ?an ! upp] limb1 ! result+ effect be+ t ! two limbs are seem+ly squeez$ clos] toge!r by ! diff]5ce ( ! two refractions4 ,! v]tical diamet] is compress$ & ! circul> outl9e becomes !reby an oval outl9e ) ! less] axis v]tical & ! great] axis horizontal4 ,?\gh ! =ego+ in=mation m]ely embraces a few g5]al pr9ciples & facts1 ! read] w h no difficulty 9 und]/&+ t refraction ex]cises a v inconv5i5t di/urb+ influ5ce on obs]vations :i* relate to ! exact places ( cele/ial objects4 ,no su* obs]vations are available = mutual comp>ison1 h[ev] great ! skill ( ! obs]v]1 or ! p]fection ( 8 in/rum5t1 unless1 & until c]ta9 corrections are appli$ to ! obs]v$ positions 9 ord] to neutralise ! di/urb+ effects ( refraction4 ,9 practice ?is is usually done by means ( tables ( corrections1 ^? 9 mo/ g5]al use be+ ,bessel's4 ,inasmu* z refraction dep5ds ^u ! aque\s vap\r 9 ! atmosph]e1 its am\nt at any giv5 mom5t is affect$ by ! height ( ! b>omet] & ! temp]ature ( ! air4 ,accord+ly :51 = any purpose1 ! utmo/ precision is requir$1 x is necess>y to take into acc\nt ! height ( ! b>omet] & ! position ( ! m]cury 9 ! !rmomet] at ! mom5t 9 "q4 ,at ! z5i? !re is no refraction :atev]1 objects appe>+ project$ on ! backgr\nd ( ! sky exactly 9 ! position !y w\ld occupy 7 ! e>? altoge!r de/itute ( an atmosph]e at all4 ,! am\nt ( ! refraction increases gradually1 b 9 accordance ) a v complex law1 f ! z5i? to ! horizon4 ,?us ! displacem5t due to refraction :i* at ! z5i? is no?+ & at an altitude ( #de is only #eg becomes at ! horizon m ?an 4 ,"o v curi\s consequ5ce is involv$ 9 ! fact t ! displacem5t due to refraction is at ! horizon :at x is2 ! diamet] bo? ( ! ,sun & ,moon may be said to be 1 m or less1 s t :5 we see ! l[] edge ( ei!r ( ^! lum9>ies j t\*+ ! horizon 9 reality ! :ole disc is completely bel[ x1 & w\ld be altoge!r hidd5 by ! convexity ( ! e>? 7 x n = ! exi/5ce ( ! e>?'s atmosph]e & ! consequ5t refraction ( ! rays ( light pass+ ?r\gh x f ! ,sun 7or ,moon7 to ! obs]v]4 ,twilight is ano!r ph5om5on associat$ ) a/ronomical pr9ciples & effects :i* dep5ds 9 "s degree on ! ,e>?'s atmosph]e & on ! laws :i* regulate ! reflection & refraction ( light4 ,aft] ! ,sun has set x cont9ues to illum9ate ! cl\ds & upp] /rata ( ! air j z x may (t5 be se5 %9+ on ! tops ( hills long aft] x has disappe>$ f ! view ( ! inhabitants ( ! pla9s bel[1 & inde$ may illum9ate ! *imneys ( a h\se :5 x is no long] visible to a p]son /&+ 9 ! g>d5 bel[4 ,! air & cl\ds ?us illum9at$ reflect "s ( ! ,sun's light to ! surface ( ! e>? ly+ imm$iately und]nea?1 & ?us produce aft] sun-set & be=e sun-rise1 9 a degree m or less consid]able accord+ z ! ,sun is only a little or is mu* depress$ bel[ ! horizon1 t lum9\s gl[ :i* we call 8twilight40 ,?is ^w is ( ,saxon orig9 & implies ! pres5ce ( a tw91 or d\ble1 light4 ,z soon z ! ,sun has disappe>$ bel[ ! horizon all ! cl\ds ov]head cont9ue = a few m9utes s highly illum9at$ z to reflect sc>cely less light ?an ! direct light ( ! ,sun4 ,z1 h[ev]1 ! ,sun gradually s9ks l[] & l[]1 less & less ( ! visible atmosph]e receives any portion ( its light1 & consequ5tly less & less is reflect$ m9ute by m9ute to ! ,e>? at ! obs]v]'s /ation until at l5g? ! "t comes :5 !re is no sunlight to be reflect$--& x is night4 ,! conv]se ( all ?is happ5s be=e & up to sun-rise2 night ceases1 twilight ensues1 gradually becom+ m def9ite2 ! dawn appe>s1 & f9ally ! full ,sun bur/s =?4 ,x may "h be /at$ z a note by ! way t ! circum/ances "u :i* ! ,sun fir/ %[s itself aft] x has ris5 above ! horizon has "s be>+ on ! probable "* ( ! wea!r :i* is at h&4 ,:5 ! fir/ indications ( day-light are se5 above a bank ( cl\ds x is ?\ght to be a sign ( w9d2 b if ! fir/ /reaks ( light are discov]$ l[ d[n1 t is 91 or v ne> ! horizon1 fair wea!r may be expect$4 ,twilight is usually reckon$ to la/ until ! ,sun has sunk #ah bel[ ! horizon1 b ! "q ( its duration dep5ds on :]e ! obs]v] is /ation$1 on ! season ( ! ye>1 & 79 a slight degree7 on ! condition ( ! atmosph]e4 ,! g5]al rule is t ! twilight is lea/ 9 ! tropics & increases z ! obs]v] moves away f ! equator t[>ds ei!r pole4 ,:il/ 9 ! tropics a depression ( #af or #ag is suffici5t to put an end to ! ph5om5on1 9 ! latitude ( ,engl& a depression ( f #ag to #bj is requir$4 ,z impli$ above1 x v>ies ) ! latitude2 & z reg>ds ! diff]5t seasons ( ! ye>1 x is lea/ on ,m>* #a & ,octob] #ab1 be+ ?ree weeks be=e ! v]nal equ9ox & ?ree weeks aft] ! autumnal equ9ox4 ,! duration at ! equator may be ab\t #a h\r #ab m9utes2 x am\nts to ne>ly #b h\rs at ! latitude ( ,gre5wi*1 & s on t[>ds ! pole4 ,at ea* pole 9 turn ! ,sun is bel[ ! horizon = #f mon?s1 b z x is less ?an #ah bel[ ! horizon = ab\t #c ( ^? #f mon?s x may be said t !re is a cont9ual twilight = ^? #c mon?s4 ,some?+ ( ! same sort ( ?+ z ?is occurs 9 ! latitude ( ,gre5wi*1 = !re is no true night at ,gre5wi* f ,may #bb to ,july #ba1 b con/ant twilight f sunset to sunrise1 or #b mon?s ( twilight 9 all4 ,?\gh twilight at ! equator is commonly set d[n z la/+ ab\t an h\r1 ?is p]iod is !re1 z else:]e1 affect$ by ! elevation ( ! obs]v] above ! sea-level4 ,:]e ! air is v r>ifi$1 z at places situat$ z ,quito & ,lima are1 ! twilight is said to la/ no m ?an #bj m9utes1 & ?is w\ld accord ) ! !ory t :]e !re is no air at all 7e4g41 on ! ,moon7 !re is no twilight at all4 ,! great] purity & cle>ness ( m\nta9 air1 r>ifi$ z x is1 is ano!r cause :i* contributes to v>y by r$uc+ ! duration ( twilight4 ,x is sometimes /at$ t a second>y twilight may be notic$1 & ,sir ,john ,h]s*el has spok5 ( x z 8consequ5t on a re-reflection ( ! rays disp]s$ ?r\gh ! atmosph]e 9 ! prim>y "o4 ,! ph5om5on se5 9 ! cle> atmosph]e ( ! ,nubian ,des]t1 describ$ by travell]s "u ! "n ( ! #8aft]gl[1' w\ld seem to arise f ?is cause40 ,i am n acqua9t$ ) any records :i* ?r[ light on ^! rem>ks ( ,sir ,john ,h]s*el4 ,! ph5om5on ( tw9kl+ is a subject :i* has be5 mu* neglect$1 possibly on acc\nt ( its app>5t1 b only app>5t1 simplicity4 ,! famili> v]se ( our days ( *ildhood-- 8,tw9kle1 tw9kle little />1 ,h[ ,i wond] :at y are1 ,up above ! e>? s high1 ,l a diamond 9 ! sky10 conta9s ev5 9 ?is simple =m a good deal ( food = reflection2 :il/ ! new v]sion-- 8,tw9kle1 tw9kle little />1 ,n[ we've f\nd out :at y are1 ,:5 unto ! midnight sky ,we ! spectroscope apply10 does s yet m4 ,z an optical ph5om5on ! tw9kl+1 or to use ! m sci5tific phrase1 ! sc9tillation1 ( ! />s is a matt] :i* has be5 /rangely ignor$ by physici/s4 ,inde$1 ! only inve/igators :o seem to h dealt ) x 9 any sort ( detail are two ,italians1 ,sec*i & ,respighi1 ,duf\r1 a ,fr5*man1 ,montigny1 a ,belgian1 & ! ,rev4 ,e4 ,l$g]1 an ,engli%man4 ,sec*i has truly rem>k$ t ! tw9kl+ ( ! />s is "o ( ! mo/ beautiful ( ! m9or ph5om5a ( ! heav5s4 ,light1 sometimes bright1 sometimes feeble1 sometimes :ite1 sometimes r$1 d>ts ab\t 9 int]mitt5t gleams1 l ! sp>kl+ fla%es ( a well-cut diamond1 & works ^u ! feel+s ( ev5 ! mo/ /olid spectator4 ,! !ory ( tw9kl+ is /ill surr\nd$ by _m difficulties4 ,"o ?+1 h[ev]1 is c]ta9--x has no?+ to d ) recurr5t *anges 9 ! intr9sic light or physical condition ( ! /> itself1 b arises dur+ ! passage ( its rays ?r\gh our atmosph]e2 x dep5ds1 !re=e1 9 "s way or o!r on ! v>y+ conditions ( ! atmosph]e4 ,on ! summit ( high m\nta9s1 accord+ to ! obs]vations ( all c>eful obs]v]s 7notably ,tac*9i1 :o /udi$ ! subject on ,m\nt ,etna71 ! light ( ! />s is /eady1 l t ( ! planets2 & x is s likewise dur+ ! h\rs ( calm :i* (t5 prec$e t]re/rial /orms4 ,! vibrations are usually m frequ5t ne> ! horizon1 & dim9i% ) ! elevation ( ! /> above ! horizon2 9 o!r words1 ) ! less5+ ( ! ?ickness ( ! atmosph]ic /rata :i* ! rays ( light h to trav]se4 ,nev]!less1 dur+ w9dy wea!r1 & specially ) nor!rly w9d1 x may be notic$ t ! />s tw9kle high up above ! horizon1 & ev5 z f> z ! z5i?4 ,f ^! & o!r simil> consid]ations we are ju/ifi$ 9 draw+ ! conclusion t tw9kl+ l>gely dep5ds on ! condition & movem5ts ( ! atmosph]e4 ,sec*i fur!r po9ts out t x is impossible to /udy c>efully ) ! nak$ eye all ! features ( tw9kl+1 & t telescopic assi/ance is imp]atively necess>y4 ,:51 ) ! aid ( a telescope1 we scrut9ise a /> dur+ a di/urb$ ev5+ m>k$ by mu* tw9kl+ we see an image diffus$ & undef9$ & surr\nd$ by rays1 z if sev]al images 7 sup]pos$1 & 7 jump+ ab\t rapidly4 ,on su* occasions we d n see t little def9$ disc surr\nd$ by motionless diffraction r+s1 ord9>ily indicative ( a tranquil atmosph]e4 ,) a telescope arm$ ) a m$ium p[]1 ! field ( view ( :i* is m ext5sive ?an t ( a high p[]1 we f9d t if a light tap is giv5 to ! telescope1 ! ord9>y simple image is *ang$ into a lum9\s curve1 ! p]imet] ( :i* is =m$ entirely ( a succession ( arcs exhibit+ ! col\rs ( ! ra9b[4 ,?is col\r$ curve does n1 9 pr9ciple1 diff] f :at "o sees on sw++ r\nd & r\nd 9 ! air su* a ?+ z a /ick1 ! end ( :i* is alight1 hav+ be5 fre%ly tak5 f a fire4 ,! gl[+ tip produces 9 appe>ance a cont9u\s arc1 ! result ( ! p]si/5ce ( ! image ( ! tip on ! ret9a4 ,9 su* a case ! col\r is con/ant1 because ! illum9ation result+ f ! blaz+ wood does n v>y2 b 9 ! case ( a /> ! arcs are diff]5tly col\r$ dur+ ! v brief space ( "t 9 :i* ! vibrat+ telescope transports ! image f "o side to ano!r ( ! visible field4 ,?is exp]im5t is f its nature v crude1 b ! idea 0 improv$ ^u & r$uc$ to a sy/ematic %ape by ,montigny1 :o introduc$ into 8 telescope1 at a c]ta9 di/ance f ! eyepiece1 a concave l5s ecc5trically plac$ ) respect to ! axis ( ! in/rum5t1 & endu$ ) a rapid movem5t ( rotation imp>t$ by suitable me*anism4 ,he ?us obta9$ images :i* revolv$ ) regul>ity1 & s 0 able to submit c]ta9 features ( ! ph5om5on to a def9ite sy/em ( measurem5t4 ,to cut a long /ory %ort1 ,montigny />t$ ) ! assumption 7made good by ! sequel7 t possibly />s 7 affect$ 9 _! tw9kl+ by intr9sic con/itutional diff]5ces2 & t possibly ,sec*i's classification ( />s into f\r types 7a classification :i* dep5ds on ! spectra :i* !y yield7 might put him on ! track ( "s intelligible conclusions ) respect to ! !ory ( tw9kl+4#d ,! results he ultimately arriv$ at 71 t ! yell[ & r$ />s ( ! ,i,ind & ,i,i,ird types tw9kle less rapidly ?an ! :ite />s ( ! ,i/ type4 ,:il/ ! av]age numb] ( sc9tillations p] second ( ! />s ( type ,,iii4 7 #ef1 ^? ( type ,,ii4 7 #fi1 & ^? ( type ,i4 #hf4 ,^! diff]5ces may be confid5tly said to dep5d ^u too _m obs]vations ( too _m diff]5t />s to be =tuit\s4 ,montigny also arriv$ at a numb] ( incid5tal conclusions ( consid]able int]e/4 ,! "o ma9 ?read runn+ ?r\gh !m1 is t !re is a connection betwe5 ! tw9kl+ ( a /> & its spectrum1 :i* _h nev] be=e be5 ?\ght (4 ,we are ju/ifi$1 inde$1 9 go+ s f> z to say1 t ,montigny's obs]vations po9t di/9ctly to a law on ?is subject1 ! law be+ t ! m ! spectrum ( a /> is int]rupt$ by d>k l9es1 ! less frequ5t are its sc9tillations4 ,! individual "* ( ! light1 !re=e1 emitt$ by any giv5 /> appe>s to affect its tw9kl+1 bo? z reg>ds ! frequ5cy !re( & ! col\rs display$4 ,montigny collect$ "s o!r int]e/+ facts ) ref]5ce to tw9kl+1 :i* may "h be /at$ 9 a concise =m4 ,!re is a great] display ( tw9kl+ 9 %[]y wea!r1 ?an :5 ! atmosph]e is 9 a normal condition2 & 9 w9t] ?an 9 summ]1 :atev] may be ! wea!r4 ,9 dry wea!r 9 ,spr+ & ,autumn ! tw9kl+ is ab\t ! same1 b wet has m effect 9 ,autumn ?an 9 ,spr+ 9 develop+ ! ph5om5on4 ,v>iations 9 ! b>ometric pressure & 9 ! humidity ( ! air also affect ! am\nt ( tw9kl+2 !re is m be=e a ra9y p]iod1 likely to la/ #b or #c days1 ?an be=e a s+le1 or1 s to speak1 casual ra9y day4 ,tw9kl+ also v>ies ) ! aggregate total ra9-fall ( any gr\p ( days1 be+ m pron\nc$ z ! ra9-fall is great]1 b decreas+ sudd5ly & consid]ably z soon z ! ra9y condition ( ! atmosph]e has pass$ away4 ,! numb] ( sc9tillations f\nd to be obs]vable ) ! aid ( ,montigny's in/rum5t 7:i* he call$ a 8sc9tillomtre071 v>i$ f a m9imum ( #ej dur+ ,june & ,july1 to #ig 9 ,janu>y1 & #aja 9 ,febru>y1 increas+ & decreas+ 9 regul> sequ5ce f mon? to mon?4 ,:5 an ,aurora ,borealis is visible1 !re is a m>k$ increase 9 ! am\nt ( tw9kl+4 ,x w\ld be int]e/+ to foll[ up ?is la/ nam$ discov]y by an endeav\r to asc]ta9 :e!r ! fluctuations :i* are co9cid5t 9 po9t ( "t ) an ,auroral display dep5d ^u optical consid]ations connect$ ) ! ,aurora1 or on physical consid]ations hav+ any relation to ! increas$ developm5t ( t]re/rial magnetism4 ,i h be5 ?us p>ticul> 9 unfold+ some:at fully ! pres5t /ate ( our k conc]n+ ! tw9kl+ ( ! />s1 because x is evid5t t !re are _m int]e/+ po9ts connect$ ) x1 :i* may be /udi$ by any pati5t & att5tive />-gaz]1 & :i* d n ne$ ! in/rum5tal appliances & te*nical ref9em5ts :i* are only to be f\nd 9 fully-equipp$ public & private obs]vatories4 ,x %\ld be m5tion$ 9 conclusion t ! planets tw9kle v little1 or1 m (t51 n at all4 ,?is is ma9ly due to ! fact t !y exhibit discs ( s5sible diamet] & !re=e t !re is1 z ,"y puts x1 8a g5]al un*ang+ av]age ( brightness = ! sum total ( all ! lum9\s po9ts ( :i* ! disc is compos$4 ,:51 = in/ance1 po9t ,a ( ! disc becomes d>k = a mom5t1 po9t ,b1 v ne> to x1 is j z likely to become bright2 ! int]f]5ce conditions be+ diff]5t = ! #b po9ts4 ,! diff]5t po9ts ( ! disc d n keep /ep1 s to speak1 9 _! tw9kl+40 ,! non-tw9kl+ ( planets because !y possess s5sible discs is (t5 available z a means = det]m9+ :5 a planet is look$ =1 :i*1 ( sev]al objects look$ at1 is ! planet want$ & :i* are m]ely />s4 ,,*apt] ,,vi4 ,,! ,,moon4 ,! ,moon be+ m]ely ! satellite ( a planet1 to wit1 ! ,e>?1 x %\ld1 accord+ to ! plan ( ?is book1 be includ$ 9 ! *apt] :i* deals ) its prim>y2 b = u inhabitants ( ! ,e>? ! ,moon has s _m special features ( int]e/ t x w be bett] to give x a special *apt] to itself4 ,we may reg>d ! ,moon 9 a tw(old aspect1 & consid] :at x is z a m]e object to look at1 & :at x does = u2 probably my pres5t read]s w pref] t mo/ prom95ce %all be giv5 to ! =m] aspect4 ,! ,moon z se5 ) ! nak$ eye exhibits a silv]y mass ( light1 :i* at ! epo* ( :at is call$ 8full ,moon0 has a seem+ly ev5 circul> outl9e4 ,full or n full1 its surface appe>s to be irregul>ly %ad$ or mottl$4 ,! imm$iate cause ( ?is %ad+ is ! fact t ! surface ( ! ,moon1 n be+ really smoo?1 reflects irregul>ly ! ,sun's light :i* falls ^u x4 ,! causa causans ( ?is is ! exi/5ce ( num]\s m\nta9s & valleys on its surface1 & :i* 7 fir/ discov]$ to be su* by ,galileo4 ,t !re are m\nta9s is prov$ by ! %ad[s ca/ by _! peaks on ! surr\nd+ pla9s1 :5 ! ,sun illum9ates ! ,moon obliquely--t is1 :5 ! ,moon is %9+ ei!r z a cresc5t or gibb\s4 ,su* %ad[s1 h[ev]1 disappe> at ! phase ( 8,full-,moon10 because ! ,sun's rays !n fall p]p5dicul>ly on ! ,moon's surface4 ,:5 ! ,moon pres5ts ei!r a cresc5t or a gibb\s =m 79 po9t ( fact :5 x pres5ts any =m except t ( 8,full-,moon071 ! b\nd>y l9e :i* sep>ates ! illum9at$ f ! unillum9at$ portion 7& :i* b\nd>y l9e is g5]ally spok5 ( z ! 8t]m9ator07 has a r\gh1 jagg$ appe>ance2 ?is is due to ! fact t ! ,sun's light falls fir/ on ! summits ( ! peaks1 & t ! adjac5t valleys & declivities are 9 %ade4 ,^! rema9 s till by reason ( ! ,moon's progress 9 its orbit a suffici5t "t has elaps$ = ! ,sun to p5etrate to ! bottom ( ! valleys4 ,) ?is explanation ! read] w h no difficulty 9 realis+ :y ! t]m9ator always exhibits an irregul> or jagg$ edge4 ,illu/ration3 ,fig4 #aa4--,m>e ,crisium4 7,lick ,obs]vatory photographs47 ,v>i\s m\nta9s on ! ,moon to ! numb] ( m ?an a ?\s& h be5 mapp$1 & _! elevations calculat$4 ,( ^! fully half h receiv$ names1 be+ ^? ( m5 ( v>i\s dates & nationalities1 :o h figur$ conspicu\sly 9 ! annals ( sci5ce1 includ+ "s1 h[ev]1 :o h n done s4 ,:il/ _m ( ^! m\nta9s are isolat$ elevations1 n a few =m def9ite *a9s ( m\nta9s1 & to c]ta9 ( ^! *a9s def9ite names1 borr[$ f ! ,e>?1 h be5 giv54 ,?us we f9d on maps ( ! ,moon ! 8,ap5n9es10 ! 8,alps10 ! 8,altai ,m\nta9s10 ! 8,drfel ,m\nta9s10 ! 8,caucasus ,m\nta9s10 & s on4 ,besides ! m\nta9s !re exi/ on ! ,moon a numb] ( pla9s analog\s 9 "s s5se to ! 8/eppes0 ( ,asia & ! 8prairies0 ( ,nor? ,am]ica4 ,^! 7 t]m$ 8seas0 9 ! e>ly days ( ! telescope1 because x 0 assum$ t z !y 7 s l>ge & s smoo? !y 7 va/ tracts ( wat]4 ,?is supposition has long ago be5 ov]?r[n1 b ! names h be5 reta9$ z a matt] ( conv5i5ce4 ,h5ce x comes ab\t t 9 descriptions ( ! ,moon "o meets ) su* names z ,m>e ,imbrium1 ! 8,sea ( ,%[]s02 ,m>e ,s]5itatis1 ! 8,sea ( ,s]5ity02 ,m>e ,tranquillitatis1 ! 8,sea ( ,tranquillity02 & s on4 ,x seems probable t ! s-call$ seas repres5t 9 ne>ly its orig9al =m :at 0 once ! orig9al surface ( ! ,moon be=e ! m\nta9s 7 =m$4 ,a confirmation ( ?is idea is to be f\nd 9 ! fact t ?\gh ^! pla9s are fairly level surfaces comp>$ ) ! masses ( m\nta9s :i* h$ge !m 9 on all sides1 yet ! pla9s !mselves are dott$ ov] ) inequalities 7small elevations & pits71 :i* seem to sugge/ t "s ( !m might ev5tually h develop$ into m\nta9s if ! fur!r =mation ( m\nta9s _h n be5 arre/$ by ! fiat ( ! ,creator4 ,?\gh hi!rto we h be5 speak+ ( ! m\nta9s ( ! ,moon "u t g5]ic title1 x is necess>y = ! read] to und]/& t ! ,moon's surface exhibits ev]y:]e rem>kable illu/rations ( ^? geological processes :i* we on ! e>? associate ) ! ^w 8volcano40 ,!re _c be ! lea/ d\bt t ! exi/+ surface ( ! ,moon1 z we see x1 owes all its /rik+ features to volcanic action1 diff]+ little f ! volcanic action to :i* we are accu/om$ on ! e>?4 ,t ?is !ory is well f\nd$ may be v easily inf]r$ by comp>+ ! /ructural details ( c]ta9 t]re/rial volcanoes & _! surr\nd+s ) a typical lun> m\nta91 or inde$1 ,i might say1 ) any lun> m\nta94 ,?is po9t 0 v well work$ out "s #dj ye>s ago by ,pr(essor ,piazzi ,smy?1 :o plac$ on pictorial record 8 results ( an exam9ation & survey ( ! ,peak ( ,t5]iffe4 ,any p]son see+ side by side "o ( ,smy?'s pictures ( ,t5]iffe & a picture ( any av]age lun> crat] w\ld f9d great difficulty if ! pictures 7 n labell$ 9 det]m9+ :i* 0 :i*4 ,! "o special feature ( ! ,moon1 :i* nev] fails to attract ! att5tion ( ev]ybody :o looks at our satellite = ! fir/ "t ?r\gh a telescope1 are ! crat] m\nta9s1 :i* inde$ con/itute an imm5se majority ( all ! lun> m\nta9s4 ,_! outl9e almo/ always con=ms1 m or less1 to t ( ! circle1 b :5 se5 ne> ei!r limb ( ! ,moon !y (t5 appe> consid]ably oval simply because !y are !n se5 consid]ably =e%ort5$4 ,9 _! normal =m !y exhibit a bas9 b\nd$ by a ridge1 ) a conical elevation 9 ! c5tre ( ! bas91 ! bas9 & ! cone toge!r be+ evid5tly ! result ( an upru% ( gases break+ ?r\gh ! out] cru/ ( ! ,moon & c>ry+ ) !m masses ( molt5 lava4 ,?is lava1 ) p]haps ! mat]ials 9 fragm5ts1 project$ 9 ! fir/ in/ance up into ! air1 fell back on to ! ,moon =m+ fir/ ( all ! out] edge ( ! bas91 & subsequ5tly1 z ! eruptive =ce became weak5$1 ! small c5tral accumulation1 :i* took1 z x naturally w\ld d1 a conical %ape4 ,an exp]im5tal imitation ( ! process ?us inf]r$ 0 c>ri$ out "s ye>s ago by a ,fr5* physici/1 ,b]g]on1 :o act$ ^u a v fusible mixture ( metals kn[n z ,wood's alloy by =c+ ?r\gh x a curr5t ( hot air4 ,! success ( ?is exp]im5t 0 complete1 & ,b]g]on consid]$ t 8 exp]im5ts1 tak5 z a :ole1 7 calculat$ to ?r[ mu* light on ! pa/ hi/ory ( ! ,moon4 ,sev]al obs]v]s at v>i\s times h fanci$ !y h se5 signs t ! lun> m\nta9 ,ari/>*us 0 an active volcano ev5 up to ! pres5t c5tury2 b x admits ( no d\bt t ?is idea is altoge!r a misconception1 & t :at !y saw z a fa9t illum9ation ( ! summit ( ,ari/>*us 0 no m ?an an effect ( e>?-%9e4 ,on ! g5]al "q ( volcanic action on ! ,moon1 ,sir ,john ,h]s*el summ$ up z foll[s3--8,decisive m>ks ( volcanic /ratification aris+ f successive deposits ( eject$ matt]1 & evid5t indications ( lava curr5ts1 /ream+ outw>ds 9 all directions1 may be cle>ly trac$ ) p[]ful telescopes4 ,9 ,"l ,rosse's magnific5t ,reflector ! flat bottom ( ! crat] call$ ,albategnius is se5 to be /rew$ ) blocks n visible 9 inf]ior telescopes1 :ile ! ext]ior ridge ( ano!r 7,ari/illus7 is all hat*$ ov] ) deep gulleys radiat+ t[>ds its c5tre40 ,! valleys & clefts or rills visible on ! ,moon's surface con/itute ano!r rem>kable feature 9 ! topography ( our satellite4 ,! valleys1 prop]ly s-call$1 require no p>ticul> comm5t1 because !y are j :at _! "n implies--holl[s (t5 _m miles long & sev]al miles wide4 ,! clefts or rills1 h[ev]1 are m my/]i\s1 by reason ( _! great l5g? & rem>kable n>r[ness4 ,"o is almo/ l$ to inf] t !y are naught else b cracks 9 ! lun> cru/1 ! result ( sudd5 cool+1 h[ caus$ is ( c\rse n kn[n4 ,!re is ano!r lun> feature to be m5tion$ some:at ak9 to ! =ego+ 9 appe>ance b app>5tly1 h[ev]1 ow+ its orig9 to a diff]5t cause4 ,i ref] to ! sy/ems ( bright /reaks :i*1 especially at or ne> ! "t ( full ,moon1 are se5 to radiate f sev]al ( ! l>ge/ crat]s1 & 9 p>ticul> f ,ty*o1 ,cop]nicus1 ,kepl] & ,ari/>*us4 ,^! bright /reaks ext5d 9 _m cases f> beyond :at may fairly be consid]$ z ! neighb\rhood ( ! crat]s f :i* !y />t1 trav]s+ di/ant m\nta9s1 valleys & o!r crat]s 9 a way :i* r5d]s x v difficult to assign an explanation ( _! orig94 ,!re are #ac areas on ! ,moon1 :i* us$ to be reg>d$ z 8seas10 "o ( !m1 h[ev]1 be>+ ! "n ( 8,oceanus ,procell>um10 ! 8,ocean ( ,/orms02 b besides ^! !re are sev]al bays1 t]m$ 9 ,lat9 ,s9us1 ( :i* ! mo/ important is ! ,s9us ,iridum or ! 8,bay ( ,ra9b[s10 a beautiful spot on ! nor!rn bord] ( ! ,m>e ,imbrium1 & be/ se5 :5 ! ,moon is betwe5 #i & #aj days old4 ,! summits ( ! semi-circul> range ( rocks :i* enclose ! bay are !n /rongly illum9at$ & a gre5i% %ad[ m>ks ! valley at its base4 ,by ! way1 x is wor? m5tion+ t n a few ( ! lun> seas1 s-call$1 seem to be p]vad$ by a gre5i% hue1 ?\gh no p>ticul> explanation ( ?is fact is =?com+4 ,mu* controv]sy has rang$ r\nd ! "q :e!r or n ! ,moon has an atmosph]e4 ,)\t d\bt ! prepond]ance ( op9ion is on ! negative side1 ?\gh x mu/ be admitt$ t "s obs]v]s ( em95ce h sugge/$ t !re are inde$ traces ( an atmosph]e to be _h1 b t x is extremely att5uat$ & ( no great ext5t1 o!rwise x mu/ r5d] its pres5ce discov]able by optical ph5om5a :i* x is c]ta9 _c be detect$4 ,a brief ref]5ce may "h be made to a curi\s ph5om5on sometimes se5 9 connection ) occultations ( />s by ! ,moon4 ,premis+ t an 8occultation0 is ! disappe>ance ( a /> beh9d ! solid body ( ! ,moon by reason ( ! =w>d movem5t ( ! ,moon 9 h] orbit1 x mu/ be /at$ t ?\gh g5]ally ! ,moon ext+ui%es ! />'s light in/antane\sly1 yet ?is does n inv>iably happ51 = sometimes ! /> seems to hang ^u ! ,moon's limb z if reluctant to disappe>4 ,no v cle> or satisfactory explanation ( ?is ph5om5on has yet be5 giv52 ! exi/5ce ( a lun> atmosph]e w\ld be an explanation1 & accord+ly ?is anomal\s appe>ance1 se5 on occasions1 has be5 advanc$ 9 support ( ! !ory t a lun> atmosph]e does exi/2 b1 nev]!less1 a/ronom]s d n accept t idea4 ,any "o desir\s ( c>ry+ out a c>eful /udy ( ! ,moon's surface mu/ be provid$ ) a good map1 & = g5]al purposes none is s conv5i5t or accessible z ,webb's1 r$uc$ f ,be] & ,mdl]'s ,mappa ,sel5ographica publi%$ 9 #ahcg1 ( :i* ano!r reproduction is giv5 9 ,l>dn]'s ,a/ronomy4 ,^?1 h[ev]1 :o w\ld desire to /udy ! ,moon ) ! utmo/ att5tion to detail mu/ provide !mselves ) ,s*midt's map publi%$ 9 #ahgh at ! exp5se ( ! ,g]man ,gov]nm5t4 ,:5 x is /at$ t ?is map repres5ts ! ,moon on a circle #g feet 9 diamet]1 ! size & am\nt ( detail 9 x w be readily und]/ood4 ,special books on ! ,moon furni%+ num]\s engrav+s & detail$ descriptions h be5 writt5 by ,c>p5t] & ,nasmy? 7jo9tly7 & by ,neison4 ,v>i\s attempts h be5 made to det]m9e ! am\nt ( light reflect$ by ! ,moon1 & also ! "q :e!r x yields any measurable am\nt ( heat4 ,z reg>ds ! light ( ! full ,moon comp>$ ) t ( ! ,sun1 ! e/imates range f #a_/cjjjjj to #a_/hjjjjj1 a discrepancy n p]haps great] ?an might be expect$ "u ! circum/ances ( ! case4 ,) respect to ! heat possess$ by1 or radiat$ f ! ,moon's surface1 ! conclusions ( ^? :o h attempt$ to deal ) ! matt] are less consi/5t4 ,z reg>ds ! surface ( ! ,moon itself ,sir ,john ,h]s*el 0 ( op9ion t x is heat$ at lea/ to ! temp]ature ( boil+ wat]1 b t ow+ to ! radiant heat hav+ to pass ?r\gh our atmosph]e1 :i* acts z an ob/acle1 x is no wond] t x %\ld be difficult = u to become consci\s ( its exi/5ce4 ,9 #ahdf ,melloni1 by conc5trat+ ! rays ( ! ,moon ) a l5s #c feet 9 diamet]1 ?\ght he detect$ a s5sible elevation ( temp]ature2 & 9 #ahef ,c4 ,p4 ,smy? at ,t5]iffe1 b ) inf]ior in/rum5tal appliances1 arriv$ at ! same conclusion4 ,?\gh ,pr(essor ,tyndall 9 #ahfa obta9$ a contr>y result1 yet ! mo/ rec5t exp]im5ts by ! y\ng] ,e>l ( ,rosse1 ,pr(essor ,langley1 & o!rs1 all t5d to %[ t ! ,moon does really radiate a c]ta9 inf9itesimally small am\nt ( heat4 ,p]haps1 h[ev]1 x w be be/ to give ,langley's ideas z to ?is 9 8 own words3--8,:ile we h f\nd abundant evid5ce ( heat f ! ,moon1 e me?od we h tri$1 or t has be5 tri$ by o!rs1 = det]m9+ ! "* ( ?is heat appe>s to u inconclusive2 & )\t que/ion+ t ! ,moon radiates heat e>?w>d f its soil1 we h n yet f\nd any exp]im5tal means ( discrim9at+ ) su* c]ta9ty betwe5 ?is & reflect$ heat t x is n op5 to mis9t]pretation40 ,x is obvi\s f ! =ego+ t we on ! ,e>? ne$ n conc]n ourselves v mu* ab\t lun> heat2 & ,i w only add t ,f4 ,w4 ,v1 by an +5i\s endeav\r to localise ! ,moon's radiant heat1 has be5 able1 he ?9ks1 to e/abli% ! fact t on ! "p ( ! ,moon to :i* ! ,sun is sett+1 :at he calls ! heat-gradi5t 7us+ a phrase sugge/$ by t]re/rial meteorology7 appe>s to be /eep] ?an on t "p to :i* ! ,sun is ris+4 ,g5]ally1 ,v's obs]vations accord fairly ) ,"l ,rosse's4 ,! ,moon revolves r\nd ! ,e>? 9 #bg d4 #g h4 #dc m4 #aa s4 at a mean di/ance ( #bcg1cjj miles1 9 an orbit :i* is some:at1 b n v1 ecc5tric4 ,its angul> diamet] at mean di/ance is #ca #e1 or1 say1 j ov] 4 ,! real diamet] may be call$ #bafj miles4 ,a few words w probably be expect$ by ! read] on ! subject ( lun> influ5ces on ! wea!r1 & g5]ally2 ?is be+ a matt] highly attractive to ! popul> m9d4 ,! tru? appe>s to lie1 z usual1 betwe5 two extremes ( ?\ght4 ,! ,moon1 ( c\rse1 is ! ma9 cause ( ! tides ( ! ,ocean1 & x is n entirely inconceivable t tidal *anges imp>t$ to va/ masses ( wat] may be ei!r syn*ron\s )1 or may 9 "s way eng5d]1 analog\s movem5ts 9 ! ,e>?'s atmosph]e2 ?\gh no di/9ct pro(s ( ?is1 z a det]m9ate fact1 c be br\ght =w>d4 ,!re is no d\bt :atev] t at or ne> ! "t ( full ,moon1 ev5+ cl\ds t5d to disp]se z ! ,moon comes up to ! m]idian1 & t by ! "t ! ,moon has rea*$ ! m]idian a sky previ\sly ov]ca/ w h become almo/ or q cle>4 ,sir ,john ,h]s*el has allud$ to ?is by speak+ ( a 8t5d5cy to disappe>ance ( cl\ds "u a full ,moon02 & he consid]s ?is 8fully entitl$ to rank z a meteorological fact40 ,he goes on1 n unnaturally1 to sugge/ ! obvi\s ?\ght t su* dissipation ( t]re/rial cl\ds is due to ! circum/ance t1 assum+ heat really comes by radiation f ! ,moon 7& we h se5 on a previ\s page ! probability ( ?is7 su* radiant heat w be m pot5tial if x falls on ! ,e>? p]p5dicul>ly1 z f a ,m]idian ,moon1 ?an if x comes to u at any "o locality f a ,moon l[ d[n 9 ! obs]v]'s horizon1 & !re=e has to pass ?r\gh ! d5s] /rata ( ! ,e>?'s atmosph]e & suff] mat]ial enfeeblem5t accord+ly4 ,i am aw>e t ,mr4 ,ellis1 late ( ! ,royal ,obs]vatory1 ,gre5wi*1 has s\ght to %[ by a seem+ly p[]ful array ( /ati/ics t ! idea n[ "u consid]ation is unf\nd$1 b ,i consid] t we h "h only "o m illu/ration ( ! famili> /atem5t t y c prove any?+ y l by /ati/ics4 ,i am firmly conv9c$1 z ! result ( m ?an #cj ye>s' obs]vation1 t t]re/rial cl\ds d disp]se "u ! circum/ances /at$4 ,sir ,j4 ,h]s*el add$ t 8 /atem5t proce$$ f 8 own obs]vation 8made q indep5d5tly ( any k ( su* a t5d5cy hav+ be5 obs]v$ by o!rs4 ,humboldt1 h[ev]1 9 8 ,p]sonal ,n>rative1 speaks ( x z well kn[n to ! pilots & seam5 ( ,spani% ,am]ica40 ,sir ,john ,h]s*el fur!r rem>k$3--8,arago has %[n f a comp>ison ( ra91 regi/]$ z hav+ fall5 dur+ a long p]iod1 t a slight prepond]ance 9 respect ( quantity falls ne> ! #8new' ,moon ov] t :i* falls ne> ! #8full4' ,?is w\ld be a natural & necess>y consequ5ce ( a prepond]ance ( a cl\dless sky ab\t ! #8full1' & =ms1 !re=e1 "p & p>cel ( ! same meteorological fact40 ,b]nad9 has ass]t$ x to be a fact t _m ?und]/orms occur ab\t ! p]iod ( 8new0 or 8full0 ,moon4 ,b :at ,i want mo/ to w>n ! read] aga9/ is t popul> idea 7wond]fully wide-spread x mu/ be admitt$7 t at ! epo*s ( :at are call$1 mo/ illogically1 ! ,moon's 8*anges10 *anges ( wea!r may c]ta9ly be expect$4 ,!re is absolutely no f\ndation :atev] = ?is1 & /ill m void ( au?ority 7if su* a phrase is admissible7 is a table ( imag9>y wea!r to be expect$ at *anges ( ! ,moon1 (t5 met ) 9 books publi%$ half a c5tury ago1 & /ill occasionally repr9t$ 9 ?ird-rate almanacs1 & designat$ 8,dr4 ,h]s*el's ,wea!r ,table40 ,?is preci\s production is n only devoid ( au!nticity z reg>ds its "n1 b may easily be se5 to be fraudul5t 9 its reput$ facts any mon? 9 ! ye>4 ,x w\ld be beyond bo? my pres5t available space & ! legitimate objects ( ?is "w to attempt ev5 an outl9e ( ! influ5ces ov] ?+s t]re/rial ascrib$ to1 or associat$1 rightly or wrongly1 ) ! ,moon1 & ( :i* ! ^w 8lunatic0 p]haps af=ds ! mo/ famili> expon5t4 ,,*apt] ,,vii4 ,,m>s4 ,m>s1 ?\gh consid]ably small] ?an ! ,e>?1 is commonly reg>d$ z ! planet :i*1 tak5 all 9 all1 be>s mo/ resemblance to ! ,e>?1 ?\gh only "o-f\r? its size4 ,"u circum/ances :i* h already be5 briefly allud$ to 9 ,*apt] ,i41 ,m>s exhibits f "t to "t a slight phase1 b no?+ approa*+ 9 am\nt ! phases pres5t$ by ! two inf]ior planets1 ,m]cury & ,v5us4 ,:5 9 opposition to ! ,sun1 t is to say :5 on ! m]idian at midnight1 x has a truly circul> disc2 b betwe5 opposition & its two positions ( quadrature x is gibb\s4 ,at ! m9imum phase1 :i* is at ea* quadrature1 ,e4 or ,w4 z ! case may be1 ! planet resembles ! ,moon #c days f its 8full40 ,^! phases are an indication t ,m>s %9es by ! reflect$ light ( ! ,sun4 ,x is a rem>kable tribute to ,galileo's p[]s ( obs]vation t ) 8 trump]y telescope1 only a few in*es long1 he %\ld h be5 able to suspect ! exi/5ce ( a ,m>tial phase4 ,writ+ to a fri5d 9 #afaj he says3--8,i d>e n affirm t ,i c obs]ve ! phases ( ,m>s2 h[ev]1 if ,i mi/ake n1 ,i ?9k ,i already p]ceive t he is n p]fectly r\nd40 ,illu/ration3 ,fig4 #ab4--;,f\r views ( ,m>s diff]+ #ij 9 longitude 7,b>n>d74 ,! p]iod 9 :i* ,m>s p]=ms its j\rney r\nd ! ,sun 7call$ ! sid]eal p]iod7 is ab\t #fhg days2 b ow+ to ! ,e>?'s motion we are m conc]n$ ) :at is call$ ! planet's synodical p]iod ( #ghj days ?an ) its sid]eal p]iod ( #fhg days4 ,! synodical p]iod is ! int]val betwe5 two successive conjunctions or oppositions ( ! planet z reg>ds ! ,e>?1 & #ghj days be+ twice #cfe & #ej days ov]1 x foll[s t we h an opportunity ( see+ ! planet at its be/ ab\t e #b ye>s2 & ?is is "o ( ! reasons :y ,m>s has be5 s mu* & s ?or\ghly /udi$ z reg>ds its physical appe>ance4 ,( c\rse ,m>s is n equally well se5 e #b ye>s1 because x may s happ5 at a giv5 opposition t x may be at its ne>e/ to ! ,sun 7p]ihelion71 & ! ,e>? at its f>!/ f ! ,sun 7aphelion71 9 :i* case ! actual di/ance betwe5 ! two bodies w be ! greate/ possible4 ,:at is !re=e want$ is = ! planet to be ne>e/ to ! ,sun & ne>e/ to ! ,e>? at ! same "t1 "u :i* circum/ances x %9es ) a brilliancy rivall+ ,jupit]4 ,?is fav\rable comb9ation occurs once 9 #g synodical revolutions1 or ab\t e #ae ye>s4 ,! mo/ fav\rable oppositions occur at ! end ( ,augu/1 & ! lea/ fav\rable at ! end ( ,febru>y4 ,! next v fav\rable opposition w n occur until #aiji4 ,m>s may approa* to )9 ab\t #ce millions ( miles f ! ,e>? at a fav\rable opposition1 :il/ "u extreme circum/ances ! o!r way x may be no ne>] ?an #fa millions ( miles at opposition4 ,m>s 9 opposition is a v conspicu\s object 9 ! ,heav5s1 %9+ ) a fi]y r$ light :i* has always be5 reg>d$ z a peculi> attribute ( ! planet1 s mu* s t its "n1 or epi!t1 9 _m languages conveys ! idea ( 8fi]y0 or 8blaz+40 ,x is record$ t 9 ,augu/ #agai its brilliancy 0 su* z to cause a panic among/ ! public4 ,telescopically exam9$1 ,m>s is always f\nd to exhibit pat*es ( %ade ( v>i\s sizes & %apes1 &1 on ! :ole1 fairly p]man5t f ye> to ye>4 ,dur+ ! la/ few ye>s 9 p>ticul> ^! m>k+s h be5 subject$ to v c>eful scrut9y & measurem5t at ! h&s ( num]\s obs]v]s ( skill & exp]i5ce1 & arm$ 9 _m cases ) v p[]ful telescopes4 ,! conjo9t effect ( ! obs]vations obta9$ has be5 l>gely to augm5t our k ( ! planet's geography1 or 7to use ! prop] t]m7 8areography40 ,be=e describ+ ! m9ute/ details record$ & p5cill$ by ! be/ obs]v]s1 x w be be/ to speak ( ! lead+ g5]al features :i* are )9 ! grasp ( comp>atively small telescopes--say1 refractors ( #f in*es & reflectors ( #ab in*es 9 ap]ture4 ,! fir/ ?+ :i* pres5ts itself z v obvi\s on ! disc ( ,m>s1 is ! fact t c]ta9 portions are ruddy1 :il/ o!rs are gre5i% 9 hue4 ,x is g5]ally assum$ t ! r$ areas repres5t l& & ! gre5 areas wat]4 ,on ?is subject ,sir ,john ,h]s*el's rem>ks1 p5n$ ab\t half a c5tury ago1 may be said /ill to /& good4 ,he ascribes ! ruddy col\r to 8an o*rey t+e 9 ! g5]al soil1 l :at ! r$ s&/one di/ricts on ! ,e>? may possibly (f] to ! inhabitants ( ,m>s1 only m decid$40 ,! propriety ( ?is ?\ght w be be/ appreciat$ by a read] :o has travell$ ?r\gh p>ts ( ,nor? ,gl\ce/]%ire1 & se5 a succession ( pl\gh$ fields 9 t locality4 ,! deep r$ col\r ( ! soil is 9 _m places v conspicu\s4 ,x has (t5 be5 rem>k$ t ! r$ness ( ,m>s is mu* m noticeable ) ! nak$ eye ?an ) a telescope2 & ,arago c>ri$ ?is idea "o /ep fur!r 9 sugge/+ t ! high] ! optical p[] ! less ! col\r4 ,?is1 h[ev]1 might naturally be expect$4 ,! mo/ prom95t surface m>k+ on ,m>s is t kn[n z ! 8,kais] ,sea10 sometimes call$ ! 8,v-m>k0 f its resemblance to t lett]1 ?\gh a leg ( mutton w\ld be q z good a simile4 ,ea/ ( ! ,kais] ,sea & a little nor? ( ! planet's equator is a well-def9$ d>k /reak kn[n z 8,h]s*el ,,ii4 ,/rait02 :il/ on ! we/ side is ano!r %ad$ area :i* has be5 call$ 8,flamm>ion ,sea40 ,^! ?ree features are s v conspicu\s1 t1 provid$ ! hemisph]e 9 :i* !y are situat$ is fairly 9 front ( ! obs]v]1 8 telescope1 if x w %[ any?+ on ,m>s1 w %[ ^!4 ,! :ite pat*es se5 on c]ta9 occasions at ,m>s's ,n4 pole & close to its ,s4 pole =m ano!r special feature ( int]e/ connect$ ) ?is planet4 ,x admits ( no d\bt :atev] t ^! are imm5se masses ( sn[ & ice :i* und]go at /at$ int]vals *anges analog\s to ! *anges :i* we "k happ5 9 ! great fields ( ice situat$ 9 ! regions ( ! ,e>? surr\nd+ ! ,e>?'s two poles4 ,n only d ^! :ite pat*es look l sn[1 b if att5tion is paid to ! *anges !y und]go & ! epo*s at :i* ! *anges take place !re w be f\nd abundant confirmation ( ?is !ory1 = ^! pat*es decrease 9 size :5 br\ght "u ! ,sun's influ5ce on ! approa* ( summ] & increase aga9 9 size :5 ! summ] is ov] & w9t] draws ne>4 ,9 ! second half ( #ahib ! ,s\!rn ,pole 0 9 full view1 & dur+ especially ,july & ,augu/ ! dim9ution ( ! sn[ area f week to week 0 v evid5t4 ,s*iap>elli1 :o obs]v$ x ) great att5tion dur+ t season1 not$ at ! comm5cem5t ( ! season t ! sn[ rea*$ at ! fir/ z f> z latitude #gj & =m$ a pol> cap "s #abjj miles 9 diamet]4 ,its subsequ5t decrease1 h[ev]1 0 s m>k$ t two or ?ree mon?s lat] ! diamet] ( ! sn[ pat* _h dw9dl$ to no m ?an #ahj miles1 & became inde$ /ill small] at a lat] p]iod4 ,! summ] sol/ice on ,m>s occurr$ on ,octob] #ac1 #ahib1 :i* 0 !re=e ! epo* ( midsumm] = ,m>s's s\!rn hemisph]e4 ,:il/ ^! *anges 7 tak+ place 9 ! s\!rn hemisph]e1 no d\bt *anges ( ! rev]se "* 7 go+ on 9 ! nor!rn hemisph]e1 b !y 7 n visible f ! ,e>? because ! ,nor? ,pole 0 situat$ 9 t hemisph]e ( ,m>s :i* 0 turn$ away f ! ,e>?4 ,9 previ\s ye>s1 h[ev]1 ! ,nor? ,pole be+ turn$ t[>ds ! ,e>? its sn[ 0 also se5 to und]go ! same sort ( *ange2 9 o!r words1 0 se5 to melt4 ,?is happ5$1 & 0 se5 9 #ahhb1 #ahhd1 & #ahhf4 ,^! obs]vations ( ! alt]nate increase & decrease ( ! pol> sn[ on ,m>s may be view$ ) telescopes ( mod]ate p[]1 b ( c\rse x is m int]e/+ & pr(itable to wat* !m ) a l>ge telescope4 ,! fact 7= x is an und\bt$ fact7 t ! nor? pol> sn[ is conc5tric ) ! planet's axis :il/ ! s\!rn pol> pat* is ecc5tric to ! ext5t ( ab\t #ahj miles f ! s\!rn pole is "o :i* has n yet receiv$ a satisfactory explanation4 ,if bo? pat*es 7 ecc5tric s z to be exactly opposite to "o ano!r an explanation w\ld be mu* m easy = we might say t ! poles ( rotation lay 9 "o direction & ! poles ( cold 9 ano!r4 ,i h spok5 on a previ\s page ( ?ree specially conspicu\s %ad+s ( ,m>s1 & o!r simil> %ad+s to ! numb] p]haps ( a c\ple ( doz5 7 g5]ally recognis$ by a/ronom]s 7hav+ be5 mapp$ & nam$7 d[n to ab\t ! ye> #ahgg4 ,9 t ye> ! a/ronomical _w 0 />tl$ by ! ann\ncem5t t ,s*iap>elli ( ,milan1 an able & compet5t obs]v]1 _h discov]$ t ^? %ad$ areas :i* all previ\s a/ronom]s _h reg>d$ z cont95ts or va/ tracts ( l&1 7 9 reality isl&s1 t is to say1 s f>1 t ! cont95ts 9 "q 7 cut up by innum]able *annels int]sect+ "o ano!r at v>i\s angles4 ,:5 ?is discov]y 0 ann\nc$1 & old] obs]vations & draw+s came to be exam9$1 x 0 f\nd1 or at any-rate ?\ght1 t ^! s-call$ canals might be trac$ 9 draw+s ( e>li] dates by ,dawes1 ,sec*i1 & ,hold54 ,s mu* = #ahgg4 ,9 ,decemb]1 #ahha1 ! planet 0 aga9 9 opposition1 b f>!r (f 9 di/ance1 & !re=e small] 9 size ?an 9 #ahgg4 ,x 01 h[ev]1 high] up 9 ! ,heav5s z se5 at ,milan & ! wea!r appe>s to h be5 m fav\rable4 ,9 ^! alt]$ circum/ances ,s*iap>elli aga9 saw 8 canals1 b ?is "t !y 7 9 at lea/ z _m z tw5ty in/ances se5 9 duplicate2 t is to say1 a tw9 canal 0 se5 to run p>allel to ! orig9al "o at a di/ance ( f #bjj to #djj miles1 z ! case might be4 ,! exi/5ce ( n only s+le canals b ( tw9 canals seems an e/abli%$ fact1 = ,s*iap>elli's draw+s & descriptions h be5 confirm$ by compet5t te/imony2 b explanation is n[h]e2 especially 9 view ( ,s*iap>elli's own idea t ! duplication ( 8 canals is p]haps n a p]man5t feature b a p]iodical ph5om5on dep5d+ on1 or connect$ 9 "s way )1 ,m>s's seasons4 ,illu/ration3 ,fig4 #ac4--,m>s1 ,augu/ #bg1 #ahib 7,guiot74 ,sev]al po9ts /& out cle>ly e/abli%$ by ! obs]vations ( ,m>s dur+ ! opposition ( #ahid1 especially ! correctness ( ,s*iap>elli's discov]ies & maps4 ,mo/ ( ! canals orig9ally se5 by him 7 aga9 se51 & ?us _! exi/5ce 0 confirm$1 :il/ new ones 7 also notic$4 ,_m ( ^! canals 7 d\ble4 ,! great ext5t ( ! ,s4 ,pol> cap & its rapid disappe>ance z ,m>s's summ] approa*$ 0 also a special feature ( ! obs]vations ( #ahid4 ,x dw9dl$ until x became almo/ invisible1 or at be/ %[$ z a t9y speck4 ,x is ?\ght by "s obs]v]s t z ! ,pol> cap melts1 ! wat] collects r\nd ! ,pole1 & !nce fl[s ov] ! planet's surface1 giv+ rise to ! ph5om5on ( canals1 & t ?is is ! way ! planet's surface is irrigat$4 ,x may "h be rem>k$ t ! ^w 8canal10 :i* has be5 giv5 to ^! d>k /reaks cross+ & cutt+ up ! l>ge areas ( l& 9 ,m>s1 is an un=tunate "o1 sugge/+ z x does artificial ag5cy4 ,b ^! ,m>tial canals are probably1 especially ! l>ge/1 a great _m miles 9 wid? & hundr$s ( miles 9 l5g?1 ?\gh "s are small]2 & !y are probably nature's me?od ( di/ribut+ ov] ! cont95ts & l&s ( ,m>s ! wat] :i* collects r\nd ! ,pole dur+ ! rapid melt+ ( ! ,pol> sn[s4 ,! idea ( ! pres5ce ( cl\d or mi/ on ,m>s also receiv$ /rong confirmation 9 #ahid4 ,l>ge portions ( ! planet's disc 7 f\nd to be hidd5 f view4 8,h]s*el ,i4 ,cont95t0 & ! 8,m>aldi ,sea0 7bo? well-kn[n m>k+s on ,m>s1 readily visible ) small telescopes7 7 at times q obscur$ by cl\d4 ,inde$1 ! ,m>aldi ,sea 0 occasionally q blott$ out3 o!r well-kn[n m>k+s 7 also ei!r blott$ out or only fa9tly se54 ,^! facts seem almo/ to prove conclusively ! exi/5ce ( cl\d & vap\r 9 ,m>s1 especially z "s ( ^! m>k+s subsequ5tly aga9 assum$ _! ord9>y =m & col\r4 ,bright projections too 7 se5 at times on ! t]m9ator ( ,m>s1 giv+ rise to ! belief t !re are high m\nta9s on ! planet1 ?\gh "s obs]v]s reg>d$ ^! projections z high cl\ds p[]fully reflect+ ! ,sun's light4 ,m>s rotates on its axis 9 #bd;h4 #cgm4 #bbs41 a p]iod s ne>ly co9cid5t ) ! p]iod ( ! ,e>?'s rotation z greatly to facilitate ! mapp+ ( ,m>s's features by "w cont9u$ f day to day by obs]v]s :o h ! necess>y in/rum5tal means & arti/ic skill 9 h&l+ ! p5cil4 ,m>s has an atmosph]e :i* may be said to be no m ?an mod]ately d5se2 t is to say mu* less d5se ?an ! ,e>?'s atmosph]e4 ,( c\rse ! exi/5ce ( sn[1 :i* has be5 tak5 = grant$ on a previ\s page1 c>ries ) x ! exi/5ce ( wat] & aque\s vap\r--a fact capable ( indep5d5t spectroscopic pro(4 ,! incl9ation ( ,m>s's axis to ! ecliptic has n be5 asc]ta9$ ) all desirable c]ta9ty1 b if ,sir ,w4 ,h]s*el's e/imate t ! obliquity on ,m>s is #bh 7! ,e>?'s obliquity be+ #bc7 is correct1 x is evid5t t !re mu/ be a v close simil>ity betwe5 ! seasons ( ! ,e>? & ! seasons ( ,m>s1 !reby furni%+ ano!r l9k ( pro( to support ! /atem5t made at ! comm5cem5t ( ?is *apt] t1 tak5 all 9 all1 ,m>s is ! planet :i* be>s mo/ resemblance to ! ,e>?4 ,! app>5t abs5ce ( satellites 9 ! case ( ,m>s 0 long a matt] ( regret to a/ronom]s2 !y seem$ to ?9k t su* a planet ought to h at lea/ "o companion4 ,at la/1 9 #ahhg1 two 7 f\nd by ,hall at ,wa%+ton1 ,u4 ,s41 us+ a v f9e refractor ( #bf in*es ap]ture4 ,^! satellites1 :i* h be5 nam$ ,phobos & ,deimos1 are1 h[ev]1 v small1 = ,phobos at its be/ only resembles a /> ( mag4 #aa1 :il/ ,deimos is no bright] ?an a /> ( mag4 #ac2 f ?is x w be und]/ood t only v l>ge telescopes w %[ ei!r ( !m4 ,phobos revolves r\nd ,m>s 9 #g h\rs at a di/ance ( ab\t #fjjj miles1 :il/ ,deimos revolves 9 #cj h\rs at a di/ance ( ab\t #ae1jjj miles4 ,x has be5 ?\ght t nei!r ( !m c be m ?an ab\t #f or #g miles 9 diamet]1 & !re=e t !y c n af=d mu* light to _! prim>y4 ,m>s revolves r\nd ! ,sun 9 #fhf;d4 #bc;h4 #cjm41 at a mean di/ance ( #ada million ( miles1 :i* ! ecc5tricity ( its orbit may increase to #aed millions or dim9i% to #abh millions4 ,! planet's app>5t diamet] v>ies betwe5 #d 9 conjunction & #cj 9 opposition4 ,ow+ to ! great ecc5tricity ( ! orbit ! planet's app>5t diamet] z se5 f ! ,e>? v>ies v mu* at diff]5t oppositions4 ,! real diamet] is r m ?an #djjj miles4 ,,*apt] ,,viii4 ,,! ,,m9or ,,planets4 ,9 #aggb a ,g]man a/ronom] nam$ ,bode1 ( ,b]l91 drew att5tion to c]ta9 curi\s num]ical relations subsi/+ betwe5 ! di/ances ( ! v>i\s planets4 ,?is 8law10 z x has be5 sometimes call$1 usually be>s ,bode's "n1 ?\gh x 0 n he b ,j4 ,d4 ,titius ( ,wittemb]g :o really fir/ discov]$ x4 ,take ! numb]s-- #j1 #c1 #f1 #ab1 #bd1 #dh1 #if1 #aib1 #chd2 ea* ( :i* 7! second except$7 is d\ble ! prec$+2 add+ to ea* ( ^! numb]s #d we obta9-- #d1 #g1 #aj1 #af1 #bh1 #eb1 #ajj1 #aif1 #chh2 :i* numb]s approximately repres5t ! di/ances ( ! planets f ! sun express$ 9 radii ( ! ,e>?'s orbit4 ,a little table w make ! matt] m cle>4 ,planets4 ,di/ance3 ,bode's ,law4 ,true di/ance f ,sun4 ,m]cury #d #c4i ,v5us #g #g4b ,e>? #aj #aj4j ,m>s #af #ae4b ,c]es #bh #bg4g ,jupit] #eb #eb4j ,saturn #ajj #ie4d ,uranus #aif #aia4h ,neptune #chh #cjj4j ,bode hav+ exam9$ ^! relations & notic+ ! void betwe5 #af & #eb 7,c]es & ! o!r m9or planets1 & ,uranus & ,neptune also1 be+ !n unkn[n7 v5tur$ to pr$ict ! discov]y ( new planets1 & ?is idea /imulat$ him to organise a little company ( a/ronom]s to hunt = new planets4 ,be=e1 h[ev]1 ?is s*eme 0 got into work+ ord]1 ,piazzi1 director ( ! ,obs]vatory at ,pal]mo1 on ,janu>y #a1 #ahja1 not$ an #h? magnitude /> 9 ,taurus1 :i* on ! next & succe$+ nights he saw aga91 & f\nd _h mov$4 ,he obs]v$ ! /range object = #f weeks1 :5 illness int]rupt$ him4 ,h[ev] he wrote lett]s ann\nc+ :at he _h se51 "o ( !m to ,bode himself2 b ?is lett]1 ?\gh dat$ ,jan4 #bd1 did n rea* ,bode at ,b]l91 till ,m>* #bj--;a /rik+ illu/ration ( ! /ate ( ! ,po/al s]vice on ! ,cont95t less ?an #ajj ye>s ago4 ,! new body1 at fir/ assum$ to be a tailless comet1 0 ev5tually recognis$ to be a new planet2 & ! "n ( ,c]es1 ! tutel>y goddess ( ,sicily1 0 at ,piazzi's in/ance be/[$ ^u x4 ,look+ = ,c]es 9 ,m>*1 #ahjb1 ,olb]s at ,brem51 came ^u ano!r new planet1 :i* 0 aft]w>ds nam$ ,pallas4 ,at fir/ he ?\ght he _h got hold ( a new v>iable />1 b two h\rs suffic$ to %[ t ! object "u notice 0 9 motion4 ,! two new bodies 7 f\nd to be s mu* alike 9 size & appe>ance1 & 9 _! orbits1 t ,olb]s sugge/$ bo? 7 b fragm5ts ( "s l>g] body :i* _h be5 %att]$ by "s great convulsion ( nature4 ,! idea 0 a d>+ "o1 & x 0 an attractive "o1 ?\gh n[ reg>d$ z unt5able4 ,h[ev] x s]v$ ! purpose ( /imulat+ rese>*1 & ! discov]y ( ,pallas 0 foll[$ by t ( ,juno1 by ,h>d+1 at ,lili5?al #ahjd2 & ( ,ve/a1 by ,olb]s1 at ,brem5 9 #ahjg4 ,! organis$ se>* = m9or planets 0 rel9qui%$ 9 #ahaf1 presumably because no m planets seem$ to be =?com+1 & x does n appe> t any fur!r attempts 7 made by anybody till ab\t #ahcj1 :5 a ,prussian amateur1 nam$ ,h5cke ( ,driess51 pr(it+ by ! publication ( "s new /> maps put =? by ! ,b]l9 ,academy1 comm5c$ a me?odical se>* = small planets4 ,^! ,b]l9 maps1 "o = ea* h\r ( ,r4 ,a41 7 only complet$ 9 #ahei1 &1 !re=e1 ,h5cke _h only a small numb] ( !m at 8 comm& dur+ ! e>ly ye>s ( 8 lab\rs4 ,/ill x is /range t #ae ye>s elaps$ be=e 8 zeal & p]sev]ance 7 rew>d$1 8 fir/ discov]y1 ! planet ,a/ra1 n tak+ place till ,decemb] #ahde4 ,once h[ev] ! ice 0 brok5 new planets foll[$ ) consid]able rapidity1 & beg9n+ ) #ahdg1 no ye> has elaps$ )\t sev]al or _m hav+ be5 f\nd4 ,dur+ ! la/ decade ! numb] detect$ annually has be5 v great--sometimes z _m z #bj 9 a ye>1 b ?is has be5 ! result ( photography be+ br\ght to be> on ! "w4 ,x is obvi\s t if a photograph ( a giv5 field tak5 on any "o day is comp>$ ) a photograph tak5 a few days e>li] or lat]1 & any ( ! objects photograph$ h mov$1 _! *ange ( place w soon be notic$ & w be a di/9ct pro( ( _! planet>y nature4 ,x seems q c]ta9 t all ! l>g] ( ^! planets h n[ be5 f\nd1 = ! av]age brilliancy 7& ?is no d\bt means ! av]age size7 ( ^? rec5tly discov]$ has be5 /eadily dim9i%+ ye> by ye>1 & x looks z if ! limit ( visibility w soon be rea*$1 if x has n be5 rea*$ already4 ,! ?ree l>ge/ ( ^! bodies1 9 ord] ( size1 h g5]ally be5 ?\ght to be ,ve/a1 ,c]es1 & ,pallas2 b ,b>n>d1 f obs]vations made 9 #ahid1 conclud$ t ,c]es is #ebj miles 9 diamet]2 ,pallas1 #cjd miles2 & ,ve/a1 #bda miles4 ,z to all ! re/ ( ! m9or planets1 except+ ,juno1 ,horn/e9 is ( op9ion t ^? hav+ a great] diamet] ?an #be geographical miles are few 9 numb]1 & t ! majority ( !m are no l>g] ?an f #e to #ae miles 9 diamet]4 ,f :at has gone be=e ! read] w readily inf] t ^! m9or planets are ( no sort ( int]e/ to ! casual amateur :o dabbles 9 ,a/ronomy2 & inde$ t !y are ( v little int]e/ to anybody4 ,) a few g5]al /ati/ics1 !re=e1 ?is *apt] may be conclud$4 ,! total numb] ( m9or planets n[ kn[n ne>ly rea*es #ejj1 & e ye> increases ! li/2 b n1 h[ev]1 at z rapid a rate z 0 once ! case1 because ! ,g]man ma!maticians1 :o alone latt]ly h be5 will+ to tr\ble !mselves ) ! computation ( ! orbits1 are und]/ood to h ann\nc$ t !y are no long] able to keep pace ) ! discov]ies made4 ,^? :o c>e to inve/igate 9 detail ! circum/ances ( ^! planets w f9d great extremes 9 ! nature ( ! orbits4 ,:il/ ! planet ne>e/ to ! ,sun has a p]iod ( only #c ye>s1 ! mo/ di/ant occupies ne>ly #i ye>s 9 p]=m+ its j\rney r\nd ! ,sun4 ,s1 also1 !re are great diff]5ces 9 ! ecc5tricities ( ! orbits & 9 _! incl9ations to ! ecliptic4 ,:il/ "o planet revolves almo/ 9 ! plane ( ! ecliptic1 ano!r 7,pallas7 has an orbit :i* is incl9$ no less ?an #cd to ! ecliptic4 ,"o ^w1 9 conclusion1 z to ! names appli$ to ^! bodies4 ,at ! outset ! names giv5 71 )\t exception1 *os5 f ! my?ologies ( anci5t ,greece & ,rome1 b1 latt]ly1 ! mo/ fanta/ic & ridicul\s names h 9 _m cases be5 select$1 names :i* 9 too _m in/ances h s]v$ no o!r purpose ?an t ( display+ ! national or p]sonal vanity ( ! a/ronom]s :o appli$ !m to ! sev]al planets4 ,! ,fr5* are great (f5d]s 9 ?is matt]4 ,,*apt] ,,ix4 ,,jupit]4 ,! planet ,jupit] occupies1 9 "o s5se1 ! fir/ position 9 ! planet>y _w1 x be+ ! l>ge/ ( all ! planets4 ,moreov]1 ) ! exception ( ,v5us1 x is ! brighte/ ( ! planets4 ,z ) ,m>s1 & = ! l reason1 ,jupit]1 :5 9 ! positions kn[n z ! ,quadratures 7or ne> !reto71 exhibits a slight phase1 b ow+ to ! f> great] di/ance f ! ,sun ( ,jupit]1 comp>$ ) ,m>s1 ! deviation ( ! illum9at$ surface f t ( a complete circle is v small2 x is1 h[ev]1 p]ceptible at or ne> ! "t ( quadrature1 a slight %ad+ (f ( ! limb f>!/ f ! ,sun be+ traceable4 ,jupit] is notewor?y on acc\nt ( two features1 bo? ( !m m or less famili>1 at lea/ by "n1 to mo/ p--its belts & its satellites1--bo? ( :i* w be describ$ 9 due c\rse4 ,! belts are dusky /reaks1 :i* v>y f "t to "t bo? 9 bread? & numb]3 mo/ commonly two broad belts w be se5 ) two or ?ree n>r[] ones on ei!r side2 b sometimes all are r n>r[1 & _! n>r[ness is made up = by an increase 9 _! numb]4 ,illu/ration3 ,fig4 #ad4--;,jupit]1 ,novemb] #bg1 #aheg 7,dawes74 ,"u all circum/ances !y lie practically p>allel1 or ne>ly s1 to ! planet's equator4 ,x is g5]ally ?\ght t ! planet1 :atev] may be its actual /ructure or con/itution1 is surr\nd$ by a d5se cl\dy envelope1 & t ! %ad$ /reaks :i* we call belts are rifts 9 ?is atmosph]e1 :i* expose to view ! solid body ( ! planet und]nea?4 ,:e!r1 h[ev]1 ! t]m 8solid body0 is an accurate "o to be us$ 9 ?is connection is ?\ght by "s to be op5 to d\bt4 ,! laws :i* regulate ! exi/5ce ( ^! belts are q unkn[n2 inde$ x seems d\btful :e!r any laws exi/ at all1 = ! belts at "o "t appe> to und]go con/ant *ange1 :il/ at ano!r "t !y rema9 almo/ un*ang$ = sev]al mon?s4 ,x has be5 sugge/$ t :5 ! *anges are rapid x mu/ be presum$ t great atmosph]ic /orms are to be consid]$ z 9 progress1 & possibly ?is may be ! true explanation4 ,belts are commonly non-exi/5t imm$iately "u ! equator2 :il/ nor? & s\? ( ?is void space x mo/ usually happ5s t !re is "o broad belt & sev]al n>r[] ones 9 ea* hemisph]e4 ,at ea* pole ! planet's brightness is less ?an ! av]age brightness1 b x _c exactly be said t ?is is due to ! exi/5ce !re ( belts prop]ly s call$4 ,x 0 =m]ly consid]$ t no t+es ( col\r c\ld be trac$ on ,jupit] except a silv]y gray ( diff]5t degrees ( int5sity2 b dur+ ! la/ ?irty ye>s !re c be no d\bt t %ades ( br[n1 r$1 & orange1 ( no great dep?1 b yet q def9ite h be5 traceable4 ,_m obs]v]s concur 9 ?is op9ion4 ,:e!r ?is detection ( col\r is due to an absolute developm5t ( col\r dur+ ! p]iod 9 "q2 or :e!r its detection is m]ely ! result ( m c>eful scrut9y ) bett] in/rum5ts is a matt] z to :i* ! evid5ce is n cle>4 ,?\gh ! g5]al position ( ! belts is su* t !y are p>allel to ! planet's equator1 yet !re are sometimes exceptions to ?is rule1 = 9 a few v r>e in/ances a /reak 9 ! nature ( a n>r[ belt has be5 se51 incl9$ to ! equator at a decid$ angle1 p]haps #bj or ev5 m4 ,x occasionally happ5s t spots are se5 on ,jupit]'s belts4 ,sometimes ^! rema9 visible = a consid]able p]iod4 ,!y are ei!r d>k or lum9\s1 & _! orig9 is unkn[n4 ,besides ^! casual spots1 :i* are always small 9 size1 !re 0 visible dur+ _m ye>s foll[+ #ahgh a v rem>kable & conspicu\s l>ge spot1 /rongly r$ 9 col\r = sev]al ye>s1 ?\gh x aft]w>ds became mu* fa9t]4 ,?is spot exhibit$ an oval outl9e & 0 ab\t #bg1jjj miles long & #hjjj miles broad4 ,= ab\t #d ye>s x ma9ta9$ its int5se r$ col\r & its %ape almo/ unalt]$2 b aft] #ahhb1 ! %ape rema9+1 ! col\r s5sibly fad$4 ,! obs]vations :i* 7 made on ?is spot dur+ #ahhf by ,pr(essor ,h\gh at ,*icago1 ,u4 ,s41 ) an #ah-;in* refractor1 l$ him to ! op9ion t ! p]si/5ce ( ! r$ spot = s _m ye>s r5d]$ unt5able ! g5]ally accept$ !ory t ! ph5om5a se5 on ! surface ( ! planet are due to atmosph]ic causes4 ,"s a/ronom]s h ?\ght t a relation%ip subsi/s betwe5 ! spots on ! ,sun & ! spots on ,jupit]4 ,!re c]ta9ly seems an app>5t id5tity 9 po9t ( "t betwe5 ! two classes ( spots1 & on ! assumption t ! spots on ,jupit] are indicative ( di/urbances on ! planet1 ,rany>d broa*$ ! idea t bo? classes ( ph5om5a are dep5d5t on "s extrane\s cosmical *ange2 & are n relat$ z cause & effect4 ,br[n+ sugge/$ _m ye>s ago t ! r$ col\r ( ! belts is a p]iodical ph5om5on co9cid+ ) ! epo* ( ! greate/ display ( sunspots1 b ?is ?\ght does n appe> to h be5 foll[$ up by any "o4 ,spots on ,jupit] seem to h be5 fir/ record$ by ,rob]t ,hooke 9 #affd4 ,9 ! foll[+ ye> ,cass9i saw a spot :i* he f\nd to be 9 motion1 & by foll[+ x att5tively he inf]r$ t ! planet rotat$ on its axis 9 #i;h4 #efm4 ,x is a rem>kable illu/ration ( ! great c>e be/[$ by ,cass9i on 8 a/ronomical "w t ! be/ mod]n det]m9ations ( ,jupit]'s rotation-p]iod diff] f ,cass9i's e/imate by only half a m9ute4 ,be>+ 9 m9d ! enorm\s size ( ,jupit] comp>$ ) ! ,e>?1 :il/ its p]iod ( rotation is consid]ably less ?an half ! ,e>?'s1 x w be at once se5 t ! velocity ( matt] at ! planet's equator is imm5sely great--#dff miles p] m9ute aga9/ ! ,e>?'s #ag miles p] m9ute4 ,"o result ( ?is is ! great int5sity ( ! c5trifugal =ce at ! equator1 & likewise ! greatness ( ! compression ( ! planet's body at ! poles4 ,h9d has sugge/$ t ! great velocity :i* ?us evid5tly exi/s may h ! effect1 by reason ( ! developm5t ( ! heat :i* x gives rise to1 ( comp5sat+ ! planet = ! small am\nt ( heat :i* ow+ to its di/ance x receives f ! ,sun4 ,on fav\rable occasions ! brilliancy ( ,jupit] is v consid]able2 s mu* s t x rivals ,v5us & ,m>s4 ,& besides ?is1 !re appe>s to be some?+ special 9 ! nature ( ,jupit]'s surface1 = n only does x seem to radiate a mu* l>g] proportion ( ! sol> light :i* falls on x ?an d ! planets g5]ally1 b "s obs]v]s h express$ ! op9ion t x possesses inh]5t light ( its own4 ,speculations1 h[ev]1 su* z ?is mu/ always be receiv$ ) res]ve1 because ( ! evid5t difficulty ( mak+ sure ( ! facts on :i* !y mu/ be bas$4 ,"o ?+1 h[ev]1 seems less op5 to d\bt4 ,be>+ 9 m9d ! small am\nt ( heat :i* rea*es ,jupit] f ! ,sun1 !re is reason to inf] t ! cl\ds :i* c]ta9ly exi/ on ,jupit] mu/ owe _! orig9 to ! influ5ce ( "s o!r heat ?an sol> heat2 9 o!r words t ,jupit] possesses s\rces ( heat )9 itself4 ,jupit] has satellites1 #e 9 numb]4 ,! discov]y ( f\r ( ^!1 0 "o ( ! fir/ fruits ( ! inv5tion ( ! telescope1 = !y 7 f\nd by ,galileo 9 ,janu>y1 #afaj4 ,! #e? satellite is s small t x escap$ notice until z rec5tly z #ahib1 hav+ be5 discov]$ on ,septemb] #i ( t ye> by ,pr(essor ,b>n>d1 ) ! great ,lick telescope 9 ,cali=nia4 ,x is1 h[ev]1 s m9ute t "o c c\nt on "o's f+]s ! telescopes capable ( %[+ x4 ,! f\r old satellites ( ,jupit] %9e z />s ( ab\t ! #g? magnitude2 9 o!r words1 !y are suffici5tly bright to be visible ) telescopes h[ev] small3 inde$ sev]al in/ances are on record ( p]sons gift$ ) v good sight1 hav+ be5 able to see !m ) ! nak$ eye4 ,= ! /udy ( _! physical appe>ance v p[]ful optical assi/ance is necess>y1 b _! movem5ts are s rapid1 & ! ph5om5a :i* result f ^? movem5ts are s int]e/+1 t ^! bodies may be consid]$ to occupy ! fir/ place 9 ! /ock-9-trade ( e amateur a/ronom]1 :o lays himself out = planet-gaz+1 ) ! object ( pr(it+ himself or 8 fri5ds4 ,! ph5om5a "h allud$ to are kn[n z eclipses1 transits1 & occultations4 ,! f\r old satellites d n be> any names1 b are numb]$ f ! inn]mo/ outw>ds1 & are always allud$ to by _! numb]s z ,i1 ,,ii1 ,,iii & ,,iv4 ,an eclipse ( a ,jovian satellite is id5tical 9 pr9ciple ) an eclipse ( ! ,moon2 t is to say1 j z an eclipse ( ! ,moon happ5s :5 ! ,moon passes into & is lo/ 9 ! ,e>?'s %ad[1 s an eclipse ( a ,jovian satellite happ5s :5 su* satellite becomes lo/ 9 ! %ad[ ca/ by ! planet into space4 ,! ,i/ ,i,ind & ,i,i,ird satellites 9 consequ5ce ( ! smallness ( ! incl9ation ( _! orbits1 und]go eclipse once 9 e revolution r\nd _! prim>y1 b ! ,i,vth is less (t5 eclips$1 ow+ to ! jo9t effect ( its consid]able orbital incl9ation1 & ( ! di/ance to :i* x rec$es f its prim>y4 ,an occultation ( a ,jovian satellite is ak9 9 pr9ciple to an occultation ( a /> by ! ,moon4 ,z ! ,moon mov+ =w>ds sudd5ly cov]s a />1 s ! planet1 on occasions1 sudd5ly cov]s "o ( its satellites4 ,if ! satellite 9 "q is ! ,i,vth1 its disappe>ance beh9d ! planet & its reappe>ance f beh9d ! planet w bo? be visible 9 due succession4 ,?is is (t5 true also ( ! ,i,i,ird satellite1 b = reasons connect$ ) ! proximity to _! prim>y ( ! ,i/ & ,i,ind satellites1 only _! disappe>ance or reappe>ance 7n bo?7 c1 z a rule1 be obs]v$ on ! same occasion4 ,! mo/ int]e/+1 by f>1 h[ev]1 ( ! ph5om5a connect$ ) ,jupit]'s satellites are _! transits 9 front (1 t is across1 ! visible disc ( ! planet4 ,?\gh ^! transits are ( frequ5t occurr5ce1 yet !y are always int]e/+ because ( ! div]se appe>ances :i* ! satellites exhibit at diff]5t times1 & :i* _c be said to be 9 accordance ) any recognis$ laws4 ,moreov]1 9 obs]v+ ! transit ( a satellite1 we may (t5 see ! black %ad[ ca/ by ! satellite on ! planet's disc2 & ?is %ad[ w sometimes prec$e & sometimes foll[ ! satellite itself4 ,f ! fact t ! satellite g5]ally appe>s z a bright spot on a bright backgr\nd :il/ ! %ad[ is black1 or blacki%1 an inexp]i5c$ obs]v] is apt to look at ! %ad[ & ?9k he is see+ ! satellite4 ,jupit] revolves r\nd ! ,sun 9 n q #ab ye>s at a mean di/ance ( #dhc millions ( miles4 ,its app>5t diamet] v>ies betwe5 #ej & #cj accord+ to its position ) respect to ! ,e>?4 ,its true diamet] is ab\t #hh1jjj miles4 ,ow+ to its l>ge size & rapid rotation1 z has already be5 m5tion$1 ,jupit] is v mu* flatt5$ at ! poles4 ,! am\nt ( ?is 7! pol> 8compression0 z x is call$7 is ab\t #a_/af4 ,,*apt] ,x4 ,,saturn4 ,next beyond ,jupit]1 proce$+ outw>ds f ! ,sun1 we rea* ! planet ,saturn1 :i* beyond any d\bt is ! mo/ beautiful & mo/ int]e/+ ( all ! planets4 ,nobody :o has ev] _h a fairly good *ance ( see+ x c h ! lea/ d\bt t ?is is ! case4 ,briefly /at$ ! ?ree ma9 features :i* con/itute its claims are3--7#a7 ,its belts1 7#b7 its r+s1 7#c7 its satellites4 ,! belts ( ,saturn resemble g5]ally ^? ( ,jupit]1 b !y are m fa9t & less *angeable4 ,_! physical cause1 h[ev]1 may be assum$ to be ! same4 ,tak+ ! planet z a :ole1 x may be said t its ord9>y col\r is yell[i% :ite1 ! belts incl9+ to grayi% :ite2 ?\gh ! d>k belts h (t5 be5 ?\ght to exhibit a gre5i% hue4 ,lassell consid]$ t ! s\? pole is g5]ally d>k] ?an ! nor? pole & m blue 9 t+e4 ,illu/ration3 ,fig4 #ae4--,saturn1 ,jan4 #bf1 #ahhi 7,antoniadi74 ,!re is "o important p>ticul> 9 :i* ! belts ( ,saturn diff] f ^? ( ,jupit]4 ,jupit]'s belts are /raight1 :]eas ,saturn's are s5sibly curv$4 ,suppos+1 z is probable1 t ,saturn's belts are p>allel to ! planet's equator1 !n we mu/ assume t ! plane ( ?is equator makes a r consid]able angle ) ! ecliptic4 ,spots on ,saturn are v r>e4 ,:e!r ,saturn has an atmosph]e seems unc]ta91 or p]haps x may be said t "o has n be5 prov$ to exi/ b may exi/4 ,! "q ( pol> sn[ is also unc]ta91 b ,sir ,w4 ,h]s*el ?\ght he c\ld trace *anges ( hue at ! poles :i* might be due to ! melt+ ( sn[4 ,x is usual to speak ( ! planet itself "u ! "n ( ! 8,ball0 :5 x is n a "q ( ref]r+ to ! :ole ,saturnian sy/em collectively4 ,9 consequ5ce ( its di/ance f ! ,sun1 ,saturn und]goes no equival5t to a phase2 or to be m exact1 no phase c be detect$1 ?\gh !oretically :5 ! planet is 9 quadrature ! disc mu/ und]go an inf9itesimally small loss ( light4 ,?\gh ! po9t has n[-a-days no sci5tific importance1 x may p]haps be desirable j to make a brief allusion to ,sir ,w4 ,h]s*el's curi\s !ory t ,saturn 0 se5 by him to be compress$ n only at ! poles b at ! equator1 s t x resembl$ a p>allelogram ) ! corn]s r\nd$ (f4 ,x is difficult to imag9e :at c\ld h giv5 rise to ?is /range idea1 ?\gh1 ( c\rse1 ,h]s*el's good fai? 9 advanc+ x _c be call$ 9 "q4 ,i ref] to x because x w be f\nd m5tion$ 9 s _m books on a/ronomy1 (t5 "u ! "n ( ! 8squ>e-%\ld]$0 figure ( ,saturn4 ,z a !ory x may be reg>d$ z q explod$ 9 consequ5ce ( accurate measures by ,bessel1 ,ma9 & o!rs hav+ conclusively %[n t ! =m ( ! ball does n dep>t f t ( a regul> sph]oid4 ,9 ref]r+ to ,saturn g5]ally1 we speak ( its r+ 9 ! s+ul> numb]1 b1 9 po9t ( fact1 !re are sev]al r+s--?ree 9 p>ticul>4 ,! pr9cipal bright r+ is really d\ble1 & )9 ! inn]mo/ bright r+ !re is a dusky "o1 p]fect z a r+1 b n lum9\s z ! out] r+s are4 ,by way ( di/+ui%+ "o r+ f ano!r1 x is usual to adopt ,/ruve's nom5clature1 :]eby ! out]mo/ bright r+ is call$ ,a1 ! inn] bright r+ ,b1 & ! dusky r+ ,c4 ,a good engrav+ w convey m fully & m cle>ly an idea ( :at ! ,saturnian sy/em consi/s ( ?an ! fulle/ v]bal description w d4 7,see ,frontispiece47 ,to ! e>lie/ a/ronom]s :o possess$ telescopes1 ,saturn prov$ a great puzzle1 because x seem$ to und]go *anges ( %ape :i* 7 q inexplicable on any pr9ciples !n kn[n4 ,galileo1 :5 fir/ he saw x1 ?\ght x pres5t$ an oval outl9e :i* might be due to a c5tral planet hav+ a small] planet on ea* side ( x1 & accord+ly he ann\nc$ to 8 fri5d1 ,kepl]1 t ! mo/ di/ant planet 0 t]gem9um or tri-=m4 ,b great] magnify+ p[] l$ him to arrive at ! conclusion t ! planet 0 n a triple comb9ation ( sph]es1 b "o body1 ei!r oblong or oval 9 outl9e4 ,?is conclusion1 h[ev]1 0 soon f\nd to be unt5able1 because ! two 7suppos$7 tribut>y bodies gradually decreas$ 9 size until !y entirely disappe>$4 ,galileo writ+ to 8 fri5d1 ,wels]1 9 ,decemb] #afab1 ?us express$ himself3-- 8,:at is to be said conc]n+ s /range a metamorphosis8 ,are ! two less] />s consum$ aft] ! mann] ( ! sol> spots8 ,h !y vani%$ or sudd5ly fl$8 ,has ,saturn1 p]haps1 dev\r$ 8 own *ildr58 ,or 7 ! appe>ances inde$ illusion or fraud1 ) :i* ! glasses h s long deceiv$ me1 z well z _m o!rs to :om ,i h %ewn !m8 ,n[1 p]haps1 is ! "t come to revive ! well-nigh )]$ hopes ( ^? :o1 guid$ by m pr(\nd contemplations1 h discov]$ ! fallacy ( ! new obs]vations1 & demon/rat$ ! utt] impossibility ( _! exi/5ce4 ,i d n "k :at to say 9 a case s surpris+1 s unlook$ =1 & s novel4 ,! %ortness ( ! "t1 ! unexpect$ nature ( ! ev5t1 ! weakness ( my und]/&+1 & ! fe> ( be+ mi/ak5 h greatly conf\nd$ me40 ,illu/ration3 ,fig4 #af4--;,g5]al view ( ! ,phases ( ,saturn's ,r+s4 ,galileo seems to h become s out ( he>t 9 consequ5ce ( ! difficulty ( det]m9+ :at ^! *anges really meant1 t he gave up altoge!r obs]v+ ,saturn4 ,9 ! c\rse ( "t1 b by v gradual /eps1 a/ronom]s came to realise :at ! facts 74 ,! next idea t 0 broa*$1 0 t ! planet consi/$ ( simply "o c5tral ball1 & t ! excresc5ces :i* ,galileo _h be5 puzzl$ by 7 m]ely h&les z !y 7 call$1 7ans7 project+ l ! h&les1 say ( a s\p ture51 ?\gh :y !y %\ld v>y 9 size at /at$ int]vals rema9$ z great a my/]y z ev]4 ,x 0 n until ab\t #afef t ! true explanation 0 arriv$ at by a ,dut*man1 nam$ ,*ri/oph] ,huyg5s4 ,x 0 ! fa%ion 9 ^? days = sci5tific m5 to intimate to ! _w discov]ies :i* !y _h made by resort to my/]i\s anagrams1 :i* s]v$ 9 "s degree ! purpose :i* 9 ! pres5t day is s]v$ by ! law regulat+ copyright or pat5t rights4 ,accord+ly ,huyg5s publi%$ ! foll[+ s+ul> memor&um3-- aaaaaaa cccc d eeeee g h i iiiiii llll mm nnnnnnnnn oo oo pp q rr s ttttt uuuuu4 ,^! lett]s arrang$ 9 _! prop] ord] furni% ! foll[+ ,lat9 s5t5ce3-- ,annulo c+itur1 t5ui1 plano1 nusquam coha]5te1 ad eclipticam incl9ato2 :i* ,lat9 s5t5ce becomes 9 ! ,engli% tongue3-- 8,! planet is surr\nd$ by a sl5d] flat r+ incl9$ to ! ecliptic1 b :i* n[h]e t\*es ! body ( ! planet40 ,huyg5's discov]y 0 n a m]e piece ( guesswork1 = he sp5t sev]al ye>s c>efully obs]v+ ! alt]ations ( =m :i* ,saturn und]w5t1 be=e he came to ! conclusion t x 0 only ! exi/5ce ( a r+ surr\nd+ ! planet :i* w\ld expla9 ! v>i\s obs]v$ *anges4 ,x 0 by way ( gu>d+ himself f be+ robb$ ( ! fruits ( 8 discov]y :il/ he 0 accumulat+ ! necess>y pro( ( its tru?1 t he buri$ 8 ?\ghts 9 ! logogriph or anagram j quot$4 ,hav+ arriv$ at ! conclusion :i* he did1 he ?\ght himself suffici5tly sure ( 8 facts to pr$ict t 9 ,july or ,augu/ #afga1 ! planet w\ld aga9 appe> r\nd1 ! r+ becom+ invisible4 ,?is surmise prov$ practically correct1 9 s f>1 t 9 ,may #afga1 or )9 #b mon?s ( ! "t pr$ict$ by ,huyg5s1 ,cass9i saw ! planet z a simple ball unaccompani$ by any r+4 ,?is is a conv5i5t place at :i* to (f] a brief explanation ( ! *anges ( appe>ance z reg>ds ! ball & r+s :i* ,saturn und]goes4 ,^! *anges dep5d jo9tly on ,saturn's motion 9 its orbit r\nd ! ,sun1 & on ! correspond+ motion ( ! ,e>? 9 its orbit4 ,nei!r ,saturn nor ! ,e>? revolve r\nd ! ,sun exactly 9 ! ecliptic1 & ?is want ( co9cid5ce results 9 ! fact1 t twice 9 ! #bi ye>s occupi$ by ,saturn 9 j\rney+ r\nd ! ,sun1 ! plane ( its r+ is se5 edgeways by u on ! ,e>?2 :il/ at two o!r p]iods int]m$iate b equi-di/ant ! r+ is se5 op5$ out to ! wide/ possible ext5t2 t is1 s f> z we on ! ,e>? c by any possibility h a *ance ( see+ x4 ,illu/ration3 ,fig4 #ag4--,phases ( ,saturn's ,r+s at specifi$ dates4 ,! appe>ances pres5t$ by ! r+s :5 und]go+ ! trans=mations to :i* !y are subject1 w be readily und]/ood by an inspection ( ! annex$ engrav+s4 ,fig4 #ag1 indicates ! actual appe>ances 9 ! ye>s specifi$1 & ^! ye>s may be consid]$ z c>ri$ =w>d & br\ght up to date by sub/itut+ #ahgg = #ahdh1 #ahhe = #ahee1 #ahia = #ahfb1 & #ahih = #ahfi4 ,adv]t+ to fig4 #af1 x w suffice to rem>k t ! two c5tral phases ( ! r+s1 op5$ wide1 are to be deem$ co-relat$1 or inde$ id5tical 9 a geometrical s5se 7s to speak7 ! diff]5ce be+ t "o ( !m is to be deem$ to %[ ! nor!rn side ( ! r+ 7:i* is n[ 9 view & w cont9ue 9 view till #aijg7 :il/ ! o!r repres5ts ! s\!rn side1 :i* 0 9 view f #ahgg till #ahia4 ,! =ego+ is a brief /atem5t ( ! g5]al pr9ciple involv$ 9 ! *anges :i* take place1 b ! motions ( ! two planets introduce c]ta9 te*nical complications into ! details :i* w\ld be se5 by an obs]v] us+ a l>ge telescope2 ) ^!1 h[ev]1 ! ord9>y read] w n c>e to conc]n himself1 & ne$ n d s4 ,a great deal might be said ) respect to ! r+s treat$ descriptively4 ,i w n[ m5tion a few matt]s ( g5]al int]e/4 ,huyg5s reg>d$ ! app5dage to ,saturn1 ^: exi/5ce he e/abli%$1 to be a s+le r+1 b z f> back z #afge1 ,cass9i det]m9$ t ,huyg5's s+le r+ 0 really made up ( two1 "o ly+ inside ! o!r4 ,cass9i 9 ?is conclusion out/epp$ n only all ! obs]v]s ( 8 own c5tury1 b ^? ( ! succe$+ c5tury1 = ,sir ,w4 ,h]s*el ev5 #ajj ye>s aft] ,cass9i1 0 = a long "t unable to satisfy himself1 ev5 ) 8 sup]ior telescopes1 t ! black /reaks se5 9 ! r+ by ,cass9i1 & reg>d$ by him z indicative ( a sev]ance ( ! r+ into two p>ts1 really impli$ a sev]ance4 ,x is n[1 h[ev]1 accept$ z a fact t n only are ! r+s :i* are kn[n z ,a & ,b absolutely di/9ct1 b t ,a also is itself c]ta9ly duplex1 t is1 t x c]ta9ly consi/s ( two indep5d5t r+s4 ,9 addition to ?is _m compet5t obs]v]s arm$ ) p[]ful telescopes h obta9$ traces ( o!r sub-divisions1 bo? 9 ,a & ,b2 & ?\gh !re is "s want ( h>mony 9 ! details1 z /at$ by ! diff]5t obs]v]s1 yet und\bt$ly we mu/ speak ( ,saturn's r+s collectively z =m+ a multiple sy/em4 ,:at ! r+s are is a highly debatable po9t1 b ! prepond]at+ idea is t !y are n :at !y appe> to be1 namely solid masses ( matt]1 b are sw>ms ( indep5d5t fragm5ts ( matt]4 ,yet 8fragm5t0 is n ! be/ ^w to use1 because x implies t some?+ has be5 brok5 up to make ! fragm5ts4 ,r1 p]haps1 we %\ld say ) ,pr(essor ,"y1 t ! r+s are 8compos$ ( a sw>m ( sep>ate p>ticles1 ea* a little indep5d5t moon pursu+ its own pa? ar\nd ! planet4 ,! idea 0 sugge/$ long ago1 by ,j4 ,cass9i 9 #agae1 & by ,wright 9 #agej1 b 0 lo/ sight ( until ,bond reviv$ x 9 connection ) 8 discov]y ( ! dusky r+4 ,pr(essor ,b5jam9 ,pi]ce soon aft]w>ds demon/rat$ t ! r+s c\ld n be cont9u\s solids2 & ,cl]k ,maxwell f9ally %[$ t !y c be nei!r solid nor liquid %eets1 b t all ! kn[n conditions w\ld be answ]$ by suppos+ !m to consi/ ( a flock ( sep>ate & indep5d5t bodies1 mov+ 9 orbits ne>ly circul>1 & 9 "o plane--9 fact1 a sw>m ( meteors40 ,! ?ickness ( ! r+s se5 edgeways has be5 v>i\sly e/imat$4 ,sir ,j4 ,h]s*el sugge/$ #bej miles z an outside limit1 :i* ,g4 ,p4 ,bond r$uc$ to #dj miles4 ,x is g5]ally consid]$1 h[ev]1 t #ajj miles is probably n f> f ! tru?4 ,"y has po9t$ out t if a model ( !m 7 con/ruct$ on ! scale ( #a in* to repres5t #aj1jjj miles1 s t ! out] r+ ( su* a model w\ld be ne>ly #ag in*es 9 diamet]1 !n ! ?ickness ( ! r+ w\ld be repres5t$ by t ( an ord9>y %eet ( writ+ pap]4 ,consid]$ z a sy/em1 ! r+s are di/9ctly m lum9\s ?an ! planet1 & ( ! two bright r+s1 ! inn] "o is bright] ?an ! out] "o2 & ! inn] "o is less bright at its inn] edge ?an else:]e4 ,x is also to be notic$ t :5 se5 edgeways j ab\t ! "t ( ! ,saturnian equ9oxes1 :5 ! ,sun is %ift+ ov] f "o side ( ! r+ to ! o!r1 & ! r+ is dw9dl+ d[n to a n>r[ /reak1 its edges 7=m+ ! ans z !y are t]m$7 d n disappe> & reappe> at ! same "t1 & are n always ( ! same app>5t ext5t4 ,"o ansa1 inde$1 is sometimes visible )\t ! o!r1 & mo/ commonly x is ! ,ea/]n "o t is miss+4 ,to :at causes ^! v>i\s peculi>ities are due is unkn[n4 ,_m physical peculi>ities h be5 ei!r notic$ or suspect$ ) ref]5ce to ! bright r+s4 ,= in/ance1 on comp>+ "o ) ano!r1 "s p]sons h ?\ght t _! surfaces are convex1 & t !y d n lie 9 ! same plane4 ,! exi/5ce ( m\nta9s on _! surface has m ?an once be5 suspect$4 ,aga91 x has be5 fanci$ t !y are surr\nd$ by an ext5sive atmosph]e4 ,x seems h>dly likely t ! r+s w\ld h an atmosph]e & n ! ball 7or vice v]s71 &1 !re=e1 no wond] t we h no obs]vations :i* c\nt5ance ! idea t ! ball does really possess an atmosph]e4 ,?is1 inde$1 seems to fl[ f ,tr\velot's obs]vation1 t ! ball is less lum9\s at its circumf]5ce ?an at its c5tre4 ,! circum/ances ( r+ ,c1 o!rwise call$ ! 8,dusky0 or 8,crape0 r+ are z curi\s hi/orically1 z !y are my/]i\s physically4 ,9 #ahch1 ,galle ( ,breslau1 notic$ :at he ?\ght to be a gradual %ad+ (f ( ! int]ior bright r+ t[>ds ! ball4 ,?\gh he publi%$ a /atem5t ( :at he saw1 ! matt] seems to h attract$ little or no notice4 ,9 #ahej1 ,g4 ,p4 ,bond 9 ,am]ica p]ceiv$ some?+ lum9\s betwe5 ! r+ & ! ball1 & aft] repeat$ obs]vations 9 conc]t ) 8 fa!r1 came to ! conclusion t ! lum9\s appe>ance :i* he saw1 0 nei!r less nor m ?an an indep5d5t & imp]fectly illum9at$ r+ ly+ )9 ! old r+s & conc5tric ) !m4 ,be=e1 h[ev]1 tid+s ( ,bond's discov]y rea*$ ,engl&1 b a few days aft] ! discov]y 9 po9t ( actual date1 ,dawes sudd5ly notic$ "o ev5+ z ,bond _h done1 a lum9\s %ad+ )9 ! bright r+s1 :i* he 0 n long 9 f9d+ out to be 9 reality a complete r+1 except s f> t a portion ( x 0 ( c\rse hidd5 f view beh9d ! ball4 ,he1 & ,o4 ,/ruve likewise1 notic$ t ?is new ,dusky ,r+ 0 occasionally to be se5 divid$ into two or m r+s4 ,! ,dusky ,r+ is transp>5t1 ?\gh ?is fact 0 n asc]ta9$ until #aheb1 or two ye>s aft] ,bond's discov]y ( ! r+4 ,! ,dusky ,r+ is n[ recognis$ z a p]man5t feature ( ,saturn1 b h[ f> x us$ to be p]man5t1 or h[ long x has be5 s1 is a matt] wrapp$ 9 d\bt4 ,record$ obs]vations by ,pic>d 9 #afgc1 & by ,hadley 9 #agbc1 made ( c\rse ) telescopes inf9itely less p[]ful ?an ^? ( ! pres5t day1 seem to sugge/ t bo? ! obs]v]s nam$ saw ! ,dusky ,r+1 )\t1 h[ev]1 be+ able to =m a cle> conception t x 0 a r+4 ,x is /range t dur+ ! long p]iod f #agbc to #ahch1 no "o--n ev5 ,sir ,w4 ,h]s*el1 ) 8 v>i\s telescopes--%\ld h obta9$ or at lea/ h record$ any suspicion ( its exi/5ce4 ,!re is1 h[ev]1 direct evid5ce t ! ,dusky ,r+ is wid] & less fa9t ?an =m]ly4 ,?is 0 directly confirm$ by ,c>p5t] 9 #ahfc1 :o says he saw x 8ne>ly z bright z ! illum9at$ r+1 s mu* s1 t x might easily h be5 mi/ak5 = a "p ( x40 ,9 #ahhc1 ,davidson f\nd a m>k$ diff]5ce 9 ! brilliancy ( ! two ends 7ans7 ( ! r+4 ,9 #ahhi ,b>n>d 0 =tunate en\gh to obs]ve an eclipse ( "o ( ,saturn's satellites by ! r+1 b ! eclipse1 t is ! concealm5t ( ! satellite1 0 only effect$ :5 x pass$ beh9d ! bright r+s2 ! dusky r+ did n oblit]ate x1 & h5ce !re 0 obta9$ a conclusive pro( ( ! transp>5cy ( ! dusky r+4 ,b>n>d fur!r conclud$ f 8 obs]vations t !re 0 no sep>at+ space or division betwe5 ! inn] bright r+ & ! dusky r+1 z has frequ5tly be5 repres5t$ 9 draw+s4 ,?is transp>5cy ( ! ,dusky ,r+1 z a matt] ( fact1 is !re=e und\bt$2 yet :at are we to consid] to be ! mean+ ( an obs]vation by ,wray 9 #ahfa1 t :il/ look+ at ! dusky r+ edgeways ! impression 0 convey$ to 8 eye t t r+ 0 v mu* ?ick] ?an ! bright r+s8 ,a v int]e/+ "q :i* has be5 mu* discuss$ has ref]5ce to ! /ability ( ! r+s4 ,x is g5]ally agre$ t ! con/itu5t p>ticles ( ! r+s mu/ be 9 motion r\nd ! prim>y or _! equilibrium c\ld n be ma9ta9$3 almo/ equally c]ta9 is x1 & = ! l reason1 t ! r+s _c be solid4 ,( actual *ange 9 ! r+s z reg>ds _! dim5sions1 we h no satisfactory pro(1 ?\gh au?orities diff] on ! po9t1 "s ?9k+ t ! r+s are exp&+ inw>ds1 s t ultimately !y w come into contact ) ! ball1 :il/ o!rs consid] no pro( :atev] ( su* *ange c be obta9$ f any ( ! obs]vations yet made 9 ! way ( measurem5ts4 ,we mu/ n[ proce$ to consid] ! satellites ( ,saturn4 ,^! are #h 9 numb]1 #g ( :i* move 9 orbits ^: planes co9cide ne>ly ) ! planet's equator1 :il/ ! rema9+ "o is incl9$ ab\t #ab !reto4 ,"o consequ5ce ( ?is co9cid5ce 9 ! planes ( ^! satellites1 :i*1 x %\ld be /at$1 are ! #g inn]mo/1 is t !y are always visible to ! inhabitants ( bo? hemisph]es :5 !y are n actually und]go+ eclipse 9 ! %ad[ ( ,saturn4 ,! satellites are ( v>i\s sizes1 & succe$ "o ano!r 9 ! foll[+ ord]1 reckon+ f ! ne>e/1 outw>ds3--,mimas1 ,enceladus1 ,te?ys1 ,dione1 ,rhea1 ,titan1 ,hyp]ion & ,iapetus4 ,any good #b-;in* telescope w %[ ,titan2 a #c-;in* w sometimes %[ ,iapetus2 a #d-;in* w %[ ,iapetus well1 toge!r ) ,rhea & ,dione1 b h>dly ,te?ys2 all ! o!rs require l>ge telescopes4 ,if ,saturn has any inhabitants at all con/itut$ l ourselves1 :i* is highly improbable1 !y w h a *ance ( see+ cele/ial ph5om5a ( ! greate/ int]e/4 ,:at ) ! r+s surr\nd+ ! planet & #h moons 9 con/ant motion1 !re w be an endless succession ( a/ronomical sights = !m to /udy4 ,! am\nt ( light receiv$ f ! ,sun _c be mu*--b>ely #a_/ajj? :at ! e>? receives4 ,! r+ & satellites w !re=e be useful z supplem5t>y s\rces ( light2 yet ! satellites w n furni% mu*1 = x has be5 calculat$ t ! surface ( ! sky occupi$ by all ! satellites put toge!r w\ld to a dwell] on ,saturn only am\nt to #f times ! area ( ! sky cov]$ by our ,moon2 :il/ ! intr9sic brightness ( all put toge!r w\ld be no m ?an #a_/af? "p ( ! light :i* we receive f our ,moon4 ,! only physical fact wor? not+ "h 9 connection ) ! satellites conc]ns ,iapetus4 ,cass9i two c5turies ago ) 8 indiff]5t telescopes ?\ght he _h asc]ta9$ t ?is satellite 0 subject to consid]able v>iations ( brilliancy4 ,sir ,w4 ,h]s*el confirm$ ,cass9i z to ?is4 ,he f\nd t x 0 mu* less brilliant :5 trav]s+ ! ea/]n half ( its orbit ?an at o!r times4 ,two conclusions h be5 drawn f ?is fact4 ,"o is t ! satellite rotates once on its axis 9 ! same "t t x p]=ms "o revolution r\nd its prim>y2 & t !re are portions ( its surface :i* are almo/ entirely incapable ( reflect+ ! rays ( ! ,sun4 ,?is la/ nam$ supposition may p]haps be well f\nd$1 b ! =m] ne$s m pro( ?an is z yet =?com+4 ,iapetus on ! :ole may be said to %9e z a /> ( ! #i? magnitude4 ,to ?is x may be add$ t ,titan is ( ! #h? magnitude1 b all ! o!rs mu* small]4 ,illu/ration3 ,fig4 #ah4--,saturn ) ! %ad[ ( ,titan on x1 ,m>* #aa1 #ahib 7,t]by74 ,saturn revolves r\nd ! ,sun 9 a little "u #bi ye>s at a mean di/ance ( #hhf millions ( miles4 ,its app>5t diamet] v>ies betwe5 #ae & #bj2 its true diamet] may be put at #ge1jjj miles4 ,! flatt5+ ( ! poles1 or 8pol> compression0 z x is call$1 is great] ?an t ( any o!r planet1 b is usually less noticeable ?an 9 ! case ( ,jupit]1 because ! r+ is apt to di/ract ! eye1 except :5 ne> ! edgeways phase4 ,! compression may be tak5 at #a_/i4 ,,*apt] ,,xi4 ,,uranus4 ,to ! ,anci5ts ,saturn 0 ! out]mo/ planet ( ! ,sy/em1 no?+ beyond x be+ kn[n4 ,nor inde$ 0 x to be assum$ t any m c\ld possibly exi/1 because ,m]cury1 ,v5us1 ! ,e>?1 ,m>s1 ,jupit]1 & ,saturn1 ) ! ,sun1 made #g cele/ial bodies ( prime importance2 & #g 0 ! numb] ( p]fection2 & !re 0 ?us provid$ "o cele/ial body to give a "n to ea* ( ! days ( ! week4 ,b ,sci5ce is n s5tim5tal2 & :5 m5 ( ,sci5ce come ^u :at looks l a discov]y !y d _! be/ to br+ _! discov]y to a successful issue1 h[ev] mu* p's prejudices may seem to /& 9 ! way at ! mom5t4 ,on a c]ta9 ev5+ 9 ,m>*1 #agha1 ,sir ,william ,h]s*el1 !n gradually com+ into notice z a practical a/ronom]1 0 engag$ 9 look+ at diff]5t fields ( />s 9 ! con/ellation ,gem9i :5 he light$ on "o :i* at once attract$ 8 special att5tion4 ,alt]+ 8 eyepiece1 & sub/itut+ a high] magnify+ p[] he f\nd ! app>5t size ( ! my/]i\s object enl>g$1 :i* conclusively prov$ t x 0 n a />2 = x is a well-kn[n optical prop]ty ( all />s t :atev] be ! size ( telescope employ$ on !m1 & h[ev] high ! magnify+ p[] no def9ite disc ( light c be obta9$ :5 9 focus4 ,h]s*el's new f9d1 !re=e1 0 pla9ly n a />1 & no idea hav+ 9 ^? days come into m5's m9ds ( !re be+ any new planets await+ discov]y1 he ann\nc$ z a matt] ( c\rse t he _h f\nd a new comet1 s soon z he asc]ta9$ t ! new body 0 9 motion4 ,! ann\ncem5t 0 n made to ! ,royal ,society till ,april #bf1 m ?an six weeks aft] ! date ( ! actual discov]y1 an indication1 by ! way1 ( ! dilatory circulation ( news a hundr$ ye>s ago4 ,! suppos$ comet 0 obs]v$ by ,maskelyne1 ! ,a/ronom] ,royal1 f\r days aft] ,h]s*el _h fir/ se5 x1 & ,maskelyne seems to h at once got ! idea into 8 head t he 0 look+ at a planet & n at a comet4 ,z soon z possible aft] ! discov]y ( a new comet ! practice ( a/ronom]s is to endeav\r to det]m9e :at is ! %ape ( ! orbit :i* x is pursu+4 ,all attempts to c>ry out ?is 9 ! case ( ,h]s*el's suppos$ new comet prov$ abortive1 because x 0 f\nd impossible to h>monise1 except = a %ort p]iod ( "t1 ! movem5ts ( ! new body ) ! =m ( curve usually affect$ by mo/ comets1 namely1 ! p>abola4 ,x is true1 z we %all see lat] on 9 speak+ ( comets1 t a c]ta9 numb] ( ^? bodies d revolve 9 ! clos$ curve kn[n z ! ellipse1 b x is usual to calculate ! p>abolic =m fir/ ( all1 because x is ! easi] to calculate2 & to p]sev]e ) x until x pla9ly appe>s t ! p>abola w n fit 9 ) ! obs]v$ movem5ts ( ! new object4 ,?is practice 0 c>ri$ out 9 ! case ( ,h]s*el's new body1 & x 0 ev5tually f\nd t n only 0 its orbit n p>abolic2 t n only 0 its orbit n an elongat$ ellipse ( ! k9d affect$ by comets2 b t x 0 ne>ly a circle1 & z ! body itself %[$ a def9$ disc ! conclusion 0 inevitable3 x 0 9 real tru? a new planet4 ,x has n tak5 long to write ?is /atem5t1 & x w take /ill less "t = ! read] to read :at has be5 writt51 b ! result j m5tion$ occupi$ ! att5tion ( a/ronom]s _m mon?s 9 work+ out1 /ep by /ep1 9 su* a way z to make sure t no mi/ake _h be5 made4 ,:5 x 0 once cle>ly det]m9$ t ,h]s*el _h add$ a new planet to ! li/ ( kn[n planets x became an int]e/+ matt] ( inquiry to f9d out :e!r x _h ev] be5 se5 be=e2 & to settle ! "n x %\ld be>4 ,a little rese>* soon %[$ t ! new planet _h be5 se5 & record$ z a fix$ /> by v>i\s obs]v]s on #bj previ\s occasions1 beg9n+ z f> back z ,dec4 #ac1 #afij1 :5 ,flam/ead regi/]$ at ,gre5wi* z a />4 ,^! v>i\s obs]vations1 spread ov] a p]iod ( #ia ye>s1 & all record$ by obs]v]s ( skill & em95ce mat]ially help$ a/ronom]s 9 _! ef=ts to calculate accurately ! %ape & nature ( ! new planet's orbit4 ,"o obs]v]1 a ,fr5*man nam$ ,le ,monni]1 saw ! planet no less ?an #ab times betwe5 #agej & #agga1 & if he _h _h 7:i* x is kn[n he _h n7 an ord]ly & me?odical m9d1 ! glory ( ?is discov]y w\ld h be5 lo/ to ,engl& & obta9$ by ,france4 ,arago has left x on record t he 0 once %[n "o ( ^! *ance obs]vations ( ,uranus1 :i* _h be5 record$ by ,le ,monni] on an old pap] bag 9 :i* hair p[d] _h be5 sold by a p]fum]4 ,a long discussion took place on ! "q ( a "n = ! new planet4 ,bode's sugge/ion ( 8,uranus0 is n[ 9 univ]sal use1 b x is )9 ! recollection ( _m p]sons liv+ t ?is planet bore sometimes ! "n ( ! 8,georgium ,sidus0 & sometimes ! "n ( 8,h]s*el40 ,! =m] designation 0 propos$ by ,h]s*el himself 9 complim5t to 8 sov]eign & patron ,george ,,iii4 ( ,engl&2 :il/ a ,fr5* a/ronom] sugge/$ ! latt] "n4 ,h[ev]1 nei!r ( ^! appellations 0 acceptable to ! a/ronom]s ( ! ,cont95t1 :o decl>$ 9 fav\r ( a my?ological "n1 ?\gh x 0 a long "t be=e !y agre$ to accept ,bode's 8,uranus40 ,! symbol commonly us$ to repres5t ! planet is =m$ ( ,h]s*el's initial ) a little circle add$ bel[1 ?\gh ! ,g]mans employ some?+ else1 8made 9 ,g]many10 to quote a too famili> phrase4 ,! visible disc ( ,uranus is s small t none b telescopes ( ! v l>ge/ size c make any?+ ( x4 ,a few s5t5ces !re=e w dispose ( ?is "p ( ! subject4 ,! disc is usually blui% 9 t+e1 & mo/ obs]v]s :o look at x consid] x uni=mly bright1 b !re is satisfactory te/imony to ! effect t "u ! mo/ fav\rable circum/ances ( in/rum5t & atmosph]e two or m belts1 n unlike ! belts ( ,jupit]1 may be trac$4 ,f ! position 9 :i* ^! belts h be5 se5 x is inf]r$ t ! satellites ( ,uranus 7pres5tly to be m5tion$7 are unusually mu* incl9$ to ! planet's equator1 & revolve 9 a retrograde direction1 contr>y to :at is ! ord9>y rule ( ! planets & satellites4 ,x is assum$ z ! basis ( ^! ideas1 7& by analogy x is reasonable to d ?is7 t ! belts are practically p>allel to ! planet's equator1 & at "r angles to ! planet's axis ( rotation4 ,to speak ( ! planet's axis ( rotation is1 9 "o s5se1 ano!r assumption1 because available obs]vations c sc>cely be said to enable u to demon/rate t ! planet does rotate on its axis1 yet we c h no moral d\bt ab\t x4 ,taylor has sugge/$ gr\nds = ! op9ion t 8!re c be v little d\bt t ,uranus is to a v l>ge ext5t self-lum9\s1 & t we d n see x :olly by reflect$ light40 ,to ?is ,gore adds ! idea t !re is 8/rong evid5ce 9 fav\r ( ! exi/5ce ( intr9sic heat 9 ! planet40 ,uranus is att5d$ by sev]al satellites4 ,x 0 once ?\ght t !re 7 eight1 ( :i* six 7 due to ,sir ,w4 ,h]s*el1 ! o!r two be+ ( mod]n discov]y4 ,a/ronom]s are1 h[ev]1 n[ agre$ t no m ?an f\r satellites c ju/ly be recognis$ z kn[n to exi/1 & !y are s m9ute 9 size t only ! v l>ge/ telescopes w %[ !m2 & !re=e our k ( !m is extremely limit$4 ,sir ,w4 ,h]s*el's idea t he _h se5 six satellites appe>s to h result$ f 8 hav+ on "s occasions mi/ak5 "s v small />s = satellites4 ,two only ( 8 six are ?\ght to h be5 real satellites4 ,! o!r two recognis$ satellites 7 f\nd bo? 9 #ahdg1 "o by ,lassell1 & ! o!r by ,o4 ,/ruve4 ,uranus revolves r\nd ! ,sun 9 r m ?an #hd ye>s1 at a mean di/ance ( #agha millions ( miles4 ,its app>5t diamet]1 se5 f ! ,e>?1 does n v>y mu* f #c :i* corresponds to ab\t #ca1jjj miles4 ,x has be5 calculat$ t ! light receiv$ f ! ,sun by ,uranus w\ld be ab\t ! am\nt furni%$ by #cjj full ,moons se5 by u on ! ,e>?1 ?\gh ano!r au?ority increases ?is to #afgj full ,moons4 ,f ,uranus ,saturn c be se51 & p]haps ,jupit]1 bo? z inf]ior planets1 j z we see ,v5us & ,m]cury2 b all ! o!r inn] planets1 includ+ ,m>s & ! ,e>?1 w\ld be hopelessly lo/ to view1 because p]petually too close to ! ,sun4 ,possibly1 h[ev]1 !y might1 on r>e occasions1 be se5 9 transit across ! ,sun's disc4 ,neptune1 ( c\rse1 w\ld be visible & be ! only sup]ior planet4 ,! ,sun itself w\ld appe> to an obs]v] on ,uranus z a v bright />1 ) a disc ( #a ( arc 9 diamet]4 ,,*apt] ,,xii4 ,,neptune4 ,we n[ come to ! be/ kn[n planet ( ! sol> sy/em1 reckon+ outw>ds f ! ,sun1 & ?\gh ?is planet itself1 z an object to look at1 has no p>ticul> int]e/ = ! g5]al public1 yet ! hi/ory ( its discov]y is a matt] ( extreme int]e/4 ,moreov]1 x is v closely mix$ up ) ! hi/ory ( ! planet ,uranus1 :i* has j be5 describ$4 ,aft] ,uranus _h become fully recognis$ z a regul> memb] ( ! sol> sy/em1 a ,fr5* a/ronom] nam$ ,alexis ,b\v>d set himself ! task ( exhau/ively consid]+ ! movem5ts ( ,uranus ) a view ( det]m9+ its orbit ) ! utmo/ possible exactness4 ,8 available mat]ials rang$ !mselves 9 two gr\ps3--! mod]n obs]vations betwe5 #agha & #ahbj1 & ! e>ly obs]vations ( ,flam/e$1 ,bradley1 ,may]1 & ,le ,monni]1 ext5d+ f #afij to #agga4 ,b\v>d f\nd 9 sub/ance t he c\ld frame an orbit :i* w\ld fit 9 ) ea* gr\p ( obs]vations1 b t he c\ld n obta9 an orbit :i* w\ld reconcile bo? sets ( obs]vations dur+ ! #acj ye>s ov] :i* !y jo9tly ext5d$4 ,he !re=e ra%ly came to ! conclusion t ! e>li] obs]vations1 hav+ be5 made :5 me?ods & in/rum5ts 7 alike relatively imp]fect1 7 probably inaccurate or o!rwise untru/wor?y1 & _h bett] be reject$4 ,?is seem$ = a:ile to solve ! difficulty1 & results :i* he publi%$ 9 #ahba repres5t$ ) all reasonable accuracy ! !n movem5ts ( ! planet4 ,a v few ye>s1 h[ev]1 suffic$ to reveal discordances betwe5 obs]vation & !ory1 s m>k$ & regul> z to make x p]fectly cle> t x 0 n ,b\v>d's "w :i* 0 faulty b t ,uranus itself _h gone a/ray ?r\gh ! op]ation ( def9ite b z yet unkn[n causes4 ,:at ^! causes 7 c\ld only be a matt] ( surmise bas$ ^u ! evid5t fact t !re 0 "s s\rce ( di/urbance :i* 0 evid5tly ?r[+ ,uranus out ( its prop] place & regul> c\rse4 ,fir/ "o & !n ano!r a/ronom] gave att5tion & ?\ght to ! matt]1 & ev5tually ! conclusion 0 arriv$ at t !re exi/$1 m remote f ! ,sun ?an ,uranus1 an undiscov]$ planet :i* 0 able to make its influ5ce felt by d]ang+ ! movem5ts ( ,uranus 9 its ord9>y j\rney r\nd ! ,sun e #hd ye>s4 ,?is conclusion on ! "p ( a/ronom]s becom+ kn[n1 a "y ,cambridge /ud5t1 !n at ,/4 ,john's ,college1 ,john ,c\* ,adams by "n1 resolv$1 9 ,july #ahda1 to take up ! subject1 ?\gh x 0 n until #ahdc t he actually did s4 ,! problem to be solv$ 0 to sugge/ ! precise place 9 ! sky at a giv5 "t ( an imag9>y planet massive en\gh to pu%1 or pull1 out ( its normal place ! planet ,uranus1 :i* 0 evid5tly be+ pu%$ at "o "t & pull$ at ano!r4 ,x w\ld also be "p ( ! problem to pr$ict ! di/ance f ! ,sun ( ! planet ?us imag9$ to exi/4 ,adams work$ pati5tly & sil5tly at ?is v pr(\nd & difficult problem = #a ye>s :5 he f\nd himself able to =w>d to ,airy1 :o _h become ,a/ronom] ,royal aft] be+ a ,cambridge ,pr(essor1 "s provisional elem5ts ( an imag9>y planet ( a size1 at a di/ance1 & 9 a position to meet ! circum/ances4 ,x is greatly to be regrett$1 on m gr\nds ?an "o1 t ,airy did no?+ b pigeon-hole ,adams's pap]s4 ,_h he done :at might h be51 & probably 01 expect$1 t is1 _h he made !m public1 or bett] /ill _h he made telescopic use ( !m1 a long & unpleasant int]national controv]sy w\ld h be5 avoid$1 & ,adams w\ld n h be5 robb$ 9 "p ( ! well-des]v$ fruits ( 8 protract$ lab\rs4 ,we mu/ n[ turn to consid] some?+ t 0 happ5+ 9 ,france4 ,9 ! summ] ( #ahde1 j be=e ,adams _h f9i%$ 8 "w1 & "o & a half ye>s aft] he comm5c$ x a "y ,fr5*man1 :o aft]w>ds rose to great em95ce1 ,u4 ,j4 ,j4 ,le ,v]ri]1 turn$ 8 att5tion to ! movem5ts ( ,uranus ) a view ( asc]ta9+ ! cause ( _! recognis$ irregul>ity4 ,9 ,novemb] #ahde he made public ! conclusion t ^? irregul>ities did n exclusively dep5d ^u ,jupit] or ,saturn4 ,he foll[$ ?is up 9 ,june #ahdf by a second memoir to prove t an unkn[n ext]ior planet 0 ! cause ( all ! tr\ble1 & he assign$ evid5ce z to its position v mu* z ,adams _h done #h mon?s previ\sly4 ,airy on receiv+ a copy ( ,le ,v]ri]'s memoir seems s f>1 at la/1 to h be5 r\s$ t he took ! tr\ble to comp>e ,le ,v]ri]'s conclusions ) ^? ( ,adams s long 9 8 possession neglect$4 ,f9d+ t a rem>kably close accord exi/$ betwe5 ! conclusions ( ! two m51 he came to realise t bo? mu/ be ( value1 & he wrote a =tnight lat] to sugge/ to ,pr(essor ,*allis ! desirability ( 8 in/itut+ a se>* = ! suspect$ planet4 ,*allis began )9 two days1 b 0 h&icapp$ by n hav+ 9 8 possession any map ( ! />s 9 ! neighb\rhood sugge/$ z ! locale ( ! planet4 ,he lo/ no "t h[ev] 9 mak+ su* a map1 b1 ( c\rse1 ! do+ s caus$ an appreciable delay1 & x 0 n until ,septemb] #bi1 #ahdf1 t he f\nd an object :i* excit$ 8 suspicions & ev5tually prov$ to be ! planet s\ght =4 ,x 0 subsequ5tly asc]ta9$ t ! planet _h be5 record$ z a /> on ,augu/ #d & #ab1 & t ! /> ( ,augu/ #ab 0 miss+ f ! zone obs]v$ on ,july #cj4 ,! discov]y ( ! planet 0 !re=e j miss$ on ,augu/ #ab because ! results ( ea* ev5+'s "w 7 n adequately comp>$ ) :at _h gone be=e4 ,mean:ile ?+s _h n be5 /&+ /ill 9 ,france4 ,9 ,augu/ #ahdf1 ,le ,v]ri] publi%$ a ?ird memoir int5d$ to develope in=mation respect+ ! probable position ( ! planet 9 ! heav5s4 ,9 ,septemb] #bc a summ>y ( ?is ?ird memoir 0 receiv$ by ,encke at ,b]l91 accompani$ by ! reque/ t he w\ld coop]ate in/rum5tally 9 ! se>* = x4 ,encke at once direct$ two ( 8 assi/ants nam$ ,d',arre/ & ,galle to d ?is1 & !y 7 =tunately well circum/anc$ = ! task4 ,unlike ,*allis1 :o1 z we h se51 c\ld d no?+ until he _h made a map = himself1 ! ,b]l9 obs]v]s _h "o ready to h&1 :i* by good *ance _h j be5 publi%$ by ! ,b]l9 ,academy = ! "p ( ! heav5s :i* bo? ,adams & ,le ,v]ri] assign$ z ! probable locality 9 :i* ! anxi\sly desir$ planet w\ld be f\nd4 ,galle call$ out ! visible />s "o by "o :il/ ,d',arre/ *eck$ !m by ! map1 & sudd5ly he came ^u an unm>k$ object :i* at ! mom5t look$ l an #h? magnitude />4 ,! foll[+ night %[$ t ! suspici\s object 0 9 motion1 & x 0 soon asc]ta9$ to be ! trans-,uranian planet :i* 0 be+ se>*$ =4 ,! discov]y :5 ann\nc$ excit$ ! livelie/ int]e/ all ov] ! _w4 ,x did m2 x creat$ a bitt] feel+ ( res5tm5t on ! "p ( ,fr5* a/ronom]s t ! laurels claim$ by !m %\ld h be5 also claim$ 9 an equal %>e by a "y & unkn[n ,engli%man1 & accord+ly ! old cry ( 8p]fide ,albion0 arose on all sides4 ,i h be5 p>ticul> 9 /at+ ! v>i\s dates :i* belong to ?is n>rative1 9 ord] to make z cle> z possible ! facts ( ! case4 ,?is is ev5 n[ necess>y1 because ?\gh ! a/ronom]s ( ,engl& & ,g]many are will+ to give ,adams & ,le ,v]ri] ea* _! fair %>e ( ?is great discov]y1 ! same imp>tial _s is n to be f\nd 9 ,france1 = no?+ is m common1 ev5 9 ! pres5t day1 9 look+ at ,fr5* books ( a/ronomy1 ?an to f9d ,adams's "n ei!r gloss$ ov] or absolutely suppress$ altoge!r :5 ! planet ,neptune is "u discussion4 ,h[ rem>kable a discov]y ?is 01 w p]haps be realiz$1 :5 x is /at$ t ,adams 0 only #b out 9 assign+ ! position ( ! new planet1 :il/ ,le ,v]ri] 0 ev5 ne>]1 be+ b>ely #a out4 ,we "k practically no?+ respect+ ! physical appe>ance ( ,neptune1 ow+ to its imm5se di/ance f u1 & = ! l reason ! ,neptunian a/ronom]s1 if !re are any1 w "k absolutely no?+ ab\t ! ,e>?2 inde$1 _! k ( ! ,sol> ,sy/em w be re/rict$ to ,uranus1 ,saturn1 & ! ,sun4 ,ev5 ! ,sun w only h an app>5t diamet] ( ab\t #a ( arc1 &1 !re=e1 w only seem to be a v bright />1 yield+ light equal 9 am\nt1 accord+ to ,zlln]1 to ab\t #gjj full moons4 ,!re is "o satellite belong+ to ,neptune1 & z ?is has be5 calculat$ to exhibit a disc #aj 9 diamet]1 a c]ta9 am\nt ( light w no d\bt be af=d$ by x especially if1 z is n unlikely1 ,neptune is itself possess$ ( "s inh]5t lum9osity indep5d5tly ( ! ,sun4 ,! fact t ,neptune seems de/itute ( visible spots or belts1 results 9 our be+ ignorant ( ! p]iod ( its axial rotation1 ?\gh x %\ld be /at$ t 9 #ahhc1 ,maxwell ,hall 9 ,jamaica1 obs]v$ p]iodical fluctuations 9 its light1 :i* he ?\ght impli$ t ! planet rotat$ on its axis 9 r less ?an #h h\rs4 ,sev]al obs]v]s ?\ght #bj or #cj ye>s ago1 t !y _h notic$ indications ( ,neptune be+ surr\nd$ by a r+ l ,saturn's r+1 b ! evid5ce z to ?is is v inconclusive4 ,x is q c]ta9 t none b ! v l>ge/ telescopes 9 ! _w w\ld %[ any su* app5dage1 & ?is planet seems to h be5 neglect$ ( late ye>s1 by ! possessors ( su* telescopes4 ,moreov]1 if a r+ exi/$ x w\ld only op5 out to its full ext5t once 9 e #hb ye>s1 be+ ! half ( ! p]iod ( ! planet's revolution r\nd ! ,sun 7j z ,saturn's r+ only op5s out to ! fulle/ ext5t e #ad ye>s71 s t1 obvi\sly1 suppos+ suspicions ( a r+ dat+ back #cj or #dj ye>s 7 well f\nd$1 x might well be t ano!r #cj or #dj ye>s might ne$ to elapse1 be=e a/ronom]s w\ld be 9 a position to see _! suspicions revive4 ,neptune revolves r\nd ! ,sun 9 #afd ye>s1 at a mean di/ance ( #bgia millions ( miles4 ,its app>5t diamet] sc>cely v>ies f #b4 ,its true diamet] is ab\t #cg1jjj miles4 ,no compression ( ! ,poles is p]ceptible4 ,its "o satellite revolves r\nd ,neptune 9 #e days1 & 9 a retrograde direction1 at a mean di/ance ( #bbc1jjj miles1 & %9es z a /> ( ! #ad? magnitude4 ,?is is a peculi>ity :i* x only %>es ) ! satellites ( ,uranus1 s f> z x reg>ds ! planet>y memb]s ( ! ,sol> ,sy/em1 ?\gh !re are _m retrograde ,comets4 ,! "q has (t5 be5 moot$1 :e!r !re exi/s1 & belong+ to ! ,sol> ,sy/em1 a planet f>!r (f ?an ,neptune4 ,!re does seem "s evid5ce ( ?is1 z we %all bett] und]/&1 :5 we come to ! subject ( long-p]iod ,comets1 ?\gh x _c be said t mu* progress has yet be5 made 9 arriv+ at a solution ( ! problem4 ,unless !re does exi/ a trans-,neptunian planet1 a ,neptunian a/ronom] w "k v little ab\t planets1 = ,uranus & ,saturn w alone be visible to him4 ,bo? w ( c\rse be :at we call 8inf]ior planets10 & "u ! be/ ( circum/ances w cut a poor figure 9 ! ,neptunian sky4 ,,*apt] ,,xiii4 ,,comets4 ,i suppose t x is ! exp]i5ce ( all ^? :o happ5 to be 9 any s5se1 h[ev] humble1 speciali/s 9 a c]ta9 bran* ( sci5ce1 t f "t to "t1 !y are beset ) que/ions on ! "p ( _! fri5ds respect+ ^? p>ticul> matt]s :i* x is kn[n t !y h specially /udi$4 ,!re is no fault to be f\nd ) ?is ?ir/ = in=mation1 always suppos+ t x is kept )9 due b\nds2 b my motive = allud+ to x "h1 is to see :e!r any well-m>k$ conclusion c be drawn f x1 )9 my own k z reg>ds a/ronomical facts or ev5ts4 ,n[ 9 ! case ( ! sci5ce ( a/ronomy 7= :i* 9 ?is connection ,i1 = ! mom5t1 w v5ture to speak71 !re is c]ta9ly no "o dep>tm5t :i* s unfail+ly1 at all times & 9 all places1 seems to evoke su* popul> sympa?y & int]e/ z ! dep>tm5t :i* deals ) ,comets4 ,sun-spots may come & g2 bright planets may %9e m brightly2 ! ,sun or ,moon may be obscur$ by eclipses2 tempor>y />s may bur/ =?1--all ^! ?+s are )9 ! k5 ( ! g5]al public by means ( newspap]s or almanacs1 b x is a comet :i* evokes m que/ion+s & conv]sations ?an all ! o!r matt]s j ref]r$ to put toge!r4 ,:5 a new & bright comet appe>s1 or ev5 :5 any comet n v bright gets talk$ ab\t1 ! old "q is /ill fre% & v]dant--8,is !re any dang] to ! ,e>? to be appreh5d$ f collision ) a ,comet80 foll[$ by 8,:at is a ,comet80 8,:at is x made (80 8,has x ev] appe>$ be=e80 8,w x come back aga980 & s on4 ,que/ions 9 ?is /ra9 h m (t5 ?an ,i c tell ( be5 put to me4 ,!y seem ! /ock que/ions ( all :o w condesc5d to replace = five m9utes 9 ! day ! newe/ novel or ! p5d+ p>liam5t>y election4 ,x may be tak5 z a fact 7?\gh 9 no prop] s5se a rule7 t a bright & conspicu\s comet comes ab\t once 9 #aj ye>s1 & a v rem>kable comet e #cj ye>s4 ,?us we h _h dur+ ! pres5t c5tury bright comets 9 #ahaa1 #ahbe1 #ahce1 #ahdc1 #aheh1 #ahfa1 #ahgd & #ahhb1 :]e( ^? ( #ahaa1 #ahdc1 & #aheh 7 specially celebrat$4 ,te/$ !n by ei!r /&>d ( words 8bright & conspicu\s10 or 8specially celebrat$10 x may be affirm$ t a good comet is n[ due1 s let u prep>e = x by gett+ up ! subject 9 advance4 ,i w n attempt to answ] 9 regul> ord] or 9 any set =m ! que/ions :i* ,i h j m5tion$ z be+ /ock que/ions1 b !y w be answ]$ 9 sub/ance z we g along4 ,!re is "o matt] 9 connection ) comets :i* has deeply impress$ itself ^u ! public m9d1 & t is ! pres5ce or abs5ce ( a 8tail40 ,x is n too mu* to say t ! g5]ality ( p reg>d ! tail ( a comet z ! comet2 & t ?\gh an object may be a true comet f an a/ronom]'s po9t ( view1 yet if x has no tail its claims g = n\ght ) ! mass ( mank9d4 ,we h "h probably a remnant ( anci5t ?\ght1 especially ( t l9e ( ?\ght :i* 9 bygone times associat$ ,comets univ]sally ) ! idea t !y 7 especially s5t to be port5ts ( national disa/]s ( "o k9d or ano!r4 ,?is is br\ght out by numb]less anci5t au?ors1 & by none m =cibly ?an ,%akespe>e4 ,h5ce we h su* passages z ! foll[+ 9 ,julius ,cs> 7,act ii41 sc4 #b73-- 8,:5 begg>s die !re are no comets se51 ,! ,heav5s !mselves blaze =? ! dea? ( pr9ces40 ,9 ,h5ry ,,vi4 7,"p ,i41 ,act i41 sc4 #a7 we f9d ! well-kn[n passage3-- 8,comets import+ *ange ( times & /ates ,br&i% y\r cry/al tresses 9 ! sky1 ,& ) !m sc\rge ! bad revolt+ />s ,t h cons5t$ unto ,h5ry's dea?40 ,!re are 9 po9t ( fact two di/9ct ideas evolv$ "h3 7#a7 t comets are prophetic ( evil1 & 7#b7 />s pot5tial = evil4 ,!re is ano!r passage 9 ,h5ry ,,vi4 7,"p ,i41 ,act iii41 sc4 #c7 ev5 m pron\nc$3-- 8,n[ %9e x l a ,comet ( rev5ge1 ,a prophet to ! fall ( all our foes40 ,aga92 9 ,hamlet 7,act i41 sc4 #a7 we f9d3-- 8,z />s ) tra9s ( fire1 & dews ( blood1 ,disa/]s 9 ! ,sun40 ,once m2 9 ! ,tam+ ( ! ,%rew 7,act iii41 sc4 #b7 we h ! m g5]al1 b /ill emphatic en\gh1 idea express$ by ! simple words ( ref]5ce to-- 8,"s ,comet or unusual prodigy40 ,%akespe>e may be said to h liv$ at ! epo* :5 a/rology 0 9 high fav\r1 & x may be t he only gave utt]ance to ! curr5t op9ion preval5t among all classes 9 ^? /ill some:at 8,d>k ,ages0 7s call$74 ,?is1 h[ev]1 c h>dly be said ( ! au?or ( my next quotation--,john ,milton 7,p>adise ,lo/1 bk4 ,,ii473-- 8,satan /ood ,unt]rifi$1 & l a ,comet burn$1 ,t fires ! l5g? ( ,ophiu*us huge ,9 ?' ,arctic sky1 & f its horrid hair ,%akes pe/il5ce & w>40 ,jump+ ov] a c5tury we f9d ! anci5t !ory /ill 9 vogue1 or ,?omson 7,seasons1 ,summ]7 w\ld nev] h writt53-- 8,amid ! radiant orbs ,t m ?an deck1 t animate ! sky1 ,! life-infus+ suns ( o!r worlds2 ,lo6 f ! dread imm5sity ( space1 ,return+ ) accel]at$ c\rse1 ,! ru%+ comet to ! sun desc5ds2 ,&1 z he s9ks bel[ ! %ad+ e>?1 ,) awful tra9 project$ o'er ! heav5s1 ,! guilty nations tremble40 ,ev5 ,napoleon ,i4 _h s]vile flatt]]s :o1 z late z #ahjh1 tri$ to extract a/rological influ5ce out ( a comet by way ( bol/]+ up 8,old ,bony40 ,b en\gh ( poetry & fiction1 let u ha/5 back to prosaic fact4 ,illu/ration3 ,fig4 #ai4--,telescope ,comet ) a nucleus4 ,comets z objects to look at may be class$ "u ?ree =ms1 ?\gh ! same comet may und]go su* *anges z w at diff]5t epo*s 9 its c>e] cause x to put on ea* v>iety ( =m 9 succession4 ,?us ! comet ( #ahbe se5 dur+ t ye> z a brilliant nak$-eye object1 aft] be+ lo/ 9 ! sun's rays1 0 aga9 f\nd on ,april #b1 #ahbf by ,pons4 ,lam5table 7 8 cries at ! mis]able plight x 0 94 ,he describ$ x z totally de/roy$3 )\t tail1 be>d1 coma or nucleus1 a m]e spectre4 ,! simple/ =m ( comet is a m]e nebul\s mass1 almo/ always circul>1 or p]haps a little oval1 9 outl9e4 ,x may ma9ta9 ?is appe>ance ?r\gh\t its visibility2 or1 gr[+ bright] may become a comet ( ! second class1 ) a c5tral cond5sation1 :i* develop+ becomes a 8nucleus0 or head4 ,x may reta9 ?is feature = ! re/ ( its c>e]1 or may pass into ! ?ird class & ?r[ out a 8coma0 or be>d1 :i* w p]haps develop into a tail or tails4 ,do+ ?is x w n unfrequ5tly gr[ bright en\gh & l>ge en\gh to become visible to ! nak$ eye4 ,9 exceptional cases ! nucleus w become z bright z a #bnd or ev5 #a/ magnitude />1 & ! tail may acquire a l5g? ( sev]al or _m degrees4 ,9 ! la/ nam$ case ( all ! comet becomes1 p> excell5ce accord+ to ! popul> s5tim5t1 8a comet40 ,x w n[ be readily inf]r$ t ! a/ronom] 9 8 obs]vatory has to d ) _m comets :i* ! public at l>ge nev] he> (1 or if !y d he> (1 treat ) contempt1 because !y are de/itute ( tails4 ,illu/ration3 ,fig4 #bj4--,wells's ,comet ( #ahhb1 se5 9 full daylight ne> ! ,sun on ,sept4 #ah4 ,illu/ration3 ,fig4 #ba4--,qu5isset's ,comet1 ,july #i1 #ahic 7,qu5isset74 ,! tails ( comets exhibit v great v>ieties n only ( size b ( =m2 "s are long & sl5d]2 "s are long & mu* spread out t[>ds _! ends1 l quill p5s1 = in/ance2 "s are %ort & /umpy1 m]e tufts or excresc5ces r ?an tails4 ,n unfrequ5tly a tail seems to consi/ ( two p>allel rays ) no comet>y matt]1 or x may be only a v slight am\nt ( comet>y matt] traceable 9 ! int]space2 "s h "o ma9 tail consi/+ ( a pair ( rays su* z j describ$1 toge!r ) "o or m subsidi>y or (f-%oot tails4 ,! comet ( #ahbe _h five tails & ! comet ( #agdd _h six tails4 ,x might be inf]r$ f all ?is t ! tails ( comets are s exce$+ly irregul>1 unc]ta9 & casual z to be am5able to no laws4 ,?is 0 long consid]$ to be ! case2 b a ,russian obs]v] nam$ ,br$i*91 z ! result ( mu* /udy & rese>*1 has arriv$ at ! conclusion t all comet tails may be br\ght "u "o or o!r ( ?ree types2 & t ea* type is indicative ( c]ta9 di/9ct diff]5ces ( orig9 & condition :i* he consid]s himself able to def9e4 ,! fir/ type comprises tails :i* are long & /raight2 8!y are =m$0 7to quote ,"y's /atem5t ( ,br$i*9's views7 8( matt] ^u :i* ! ,sun's repulsive action is f twelve to fifte5 times z great z ! gravitational attraction1 s t ! p>ticles leave ! comet ) a relative velocity ( at lea/ f\r or five miles a second2 & ?is velocity is cont9ually increas$ z !y rec$e1 until at la/ x becomes enorm\s1 ! p>ticles travell+ sev]al millions ( miles 9 a day4 ,! /raight rays :i* are se5 9 ! figure ( ! tail ( ,donati's ,comet1 tang5tial to ! tail1 are /ream]s ( ?is fir/ type2 z also 0 ! enorm\s tail ( ! comet ( #ahfa4 ,! second type is ! curv$ plume-l tra91 l ! pr9cipal tail ( ,donati's ,comet4 ,9 ?is type ! repulsive =ce v>ies f #b4b times gravity 7= ! p>ticles on ! convex edge ( ! tail7 to half t am\nt = ^? :i* =m ! inn] edge4 ,?is is by f> ! mo/ common type ( comet>y tra94 ,a few comets %[ tails ( ! ?ird type--%ort1 /ubby1 bru%es viol5tly curv$1 & due to matt] ( :i* ! repulsive =ce is only a fraction ( gravity--f #a_/aj to 40 ,br$i*9 wi%es x to be inf]r$ t ! tails ( ! #a/ type are probably compos$ ( hydrog52 ^? ( ! #bnd type ( "s hydro-c>bon gas2 & ^? ( ! #crd ( ! vap\r ( iron1 probably ) "s admixture ( sodium & o!r sub/ances4 ,br$i*91 z a reason = ^! conclusions1 supposes t ! =ce :i* g5]ates ! tails ( comets is a repulsive =ce1 ) a surface action ! same = equal surfaces ( any k9d ( matt]2 ! effective accel]at+ =ce !re=e measur$ by ! velocity :i* x w\ld produce w\ld dep5d ^u ! ratio ( surface to mass 9 ! p>ticles act$ ^u1 & s1 9 8 view1 %\ld be inv]sely proportional to _! molecul> weights4 ,n[ x happ5s t ! molecul> weights ( hydrog51 ( hydro-c>bon gases1 & ( ! vap\r ( iron be> to ea* o!r j ab\t ! requir$ proportion4 ,i am "h /at+ ! views & op9ions ( o!rs )\t def9itely pr(ess+ to be satisfi$ ) !m1 b z !y h met ) "s acceptance1 x is prop] to *ronicle !m1 ?\gh we "k no?+ ( ! nature ( ! repulsive =ce "h talk$ ab\t4 ,x might be electric1 x might be any?+4 ,! spectroscope c]ta9ly l5ds "s c\nt5ance to ,br$i*9's views1 b we ne$ f> m k & /udy ( comets be=e we %all be ju/ly entitl$ to dogmatise on ! subject4 ,illu/ration3 ,fig4 #bb4--;,holmes's ,comet1 ,nov4 #i1 #ahib 7,d5n+74 ,illu/ration3 ,fig4 #bc4--;,holmes's ,comet1 ,nov4 #af1 #ahib 7,d5n+74 ,?is has be5 r a digression4 ,i g back n[ to prosaic matt]s ( fact1 ( :i* a va/ & int]e/+ array pres5t !mselves = consid]ation 9 connection ) comets4 ,let u consid] a little 9 detail :at !y are1 to look at4 ,we h se5 t a well-develop$ comet ( ! normal type usually comprises a nucleus1 a head or coma1 & a tail4 ,comets :i* h no tails g5]ally exhibit heads ( v simple /ructure2 & if !re is a nucleus1 ! nucleus is little else ?an a /ell> po9t ( light4 ,b 9 ! case ( ! l>g] comets1 :i* are almo/ or q visible to ! nak$ eye1 ! head (t5 exhibits a v complex /ructure1 :i* 9 n a few cases seems to convey v def9ite indications ( ! op]ations go+ on at ! "t4 ,figs4 #bb & #bc may be tak5 z samples ( a complex comet>y head1 ?\gh no two comets resemble "o ano!r exactly 9 details4 ,fig4 #bd =cibly conveys ! idea t we are look+ at a process ( developm5t analog\s to an upru% ( wat] f a f\nta91 or p]haps ,i might bett] say1 f a bur/ wat]pipe4 ,!re is a di/9ct idea ( a jet4 ,?is self-same idea1 9 ano!r =m1 pres5ts itself 9 ! case ( ^? comets :i* exhibit :at a/ronom]s are 9 ! habit ( call+ 8lum9\s envelopes40 ,! jet 9 ?is case is n /rictly a jet because x is n a cont9u\s outfl[1 or ov]fl[1 ( matt]2 ! idea r sugge/s itself ( an int]mitt5t ov]fl[ result+ 9 accumulat$ lay]s1 or /rata1 ( matt] becom+ visible4 ,b ) ?is we come to a /&/ill2 we _c tell :]e ! matt] comes f1 & /ill less1 :]e x goes to2 we c only record :at our eyes1 assi/$ by telescopes1 tell u4 ,!re c1 h[ev]1 ,i ?9k1 be no d\bt t ! matt] ( a comet becomes display$ to our s5ses z ! result ( a process ( expulsion1 or repulsion1 f ! nucleus2 & !n1 hav+ become laun*$ into space1 x comes "u ! influ5ce1 also repulsive1 ( ! ,sun4 ,all ^! ?+s are visible facts4 ,z to causes1 we sugge/ little1 because we "k s little4 ,anyone :o has se5 a comet & has wat*$ ! displays ( jets & lum9\s envelopes1 su* z ,i h endeav\r$ to set =?1 w realise at once h[ impossible x is to describe ^! ?+s 9 words4 ,!y mu/ be se5 ei!r 9 actual be+ or 9 picture4 ,"s fur!r allusions to ?is bran* ( ! subject may p]haps be m advantage\sly made aft] we h consid]$ ! movem5ts & orbits ( comets4 ,illu/ration3 ,fig4 #bd4--;,comet ,,iii4 ( #ahfb1 on ,aug #bb1 %[+ jet ( lum9\s matt] 7,*allis74 ,!re is (t5 a slight g5]al resemblance betwe5 a planet & a comet1 z reg>ds ! pa? :i* ea* class ( body pursues4 ,probably ! lea/ reflective p]son likely to be foll[+ me "h und]/&s ! b>e fact1 t all ! planets revolve r\nd ! ,sun1 & are held to def9$ orbits by ! ,sun's influ5ce1 or attraction1 z x is call$4 ,p]haps1 x is n equally realis$1 t 9 a some:at simil>1 b n q ! same way1 comets are influ5c$ & controll$ by ! ,sun4 ,comets mu/ be consid]$ z reg>ds _! motions to be divisible into two classes3--7#a7 ,^? :i* belong to ! ,sol> ,sy/em2 & 7#b7 ^? :i* d n4 ,ea* ( ^! two classes mu/ aga9 be sub-divid$1 if we w\ld really obta9 a j conception ( h[ ?+s /&4 ,by ! ,comets :i* belong to ! ,sun1 ,i mean ^? :i* revolve r\nd ! ,sun 9 clos$ orbits2#e & are1 or may be1 se5 aga9 & aga9 at recurr+ int]vals4 ,!re are #b or #c doz5 comets :i* pres5t !mselves to our gaze at /at$ int]vals1 v>y+ f ab\t #c to #gj ye>s4 ,!re are aga9 o!r comets :i* )\t any d\bt 7ma!matically7 are revolv+ r\nd ! ,sun 9 clos$ orbits1 b 9 orbits s l>ge & ) p]iods ( revolution s long 7(t5 _m c5turies71 t ?\gh !y w return aga9 to ! sight ( ! inhabitants ( ! e>? "s day1 yet no second return hav+ be5 actually record$1 ! a/ronom]'s pr$iction t !y w return1 rema9s at pres5t a pr$iction bas$ on ma!matics b no?+ m4 ,!re is ano!r class ( ,comet ( :i* we see examples f "t to "t1 & hav+ se5 !m once %all nev] see aga94 ,?is is because ^! ,comets move 9 orbits :i* are n clos$1 & :i* are kn[n z p>abolic or hyp]bolic orbits respectively1 because d]iv$ f ^? sections ( a cone :i* are call$ ! ,p>abola & ! ,hyp]bola4 ,x mu/ be und]/ood t :at ,i am n[ ref]r+ to is purely a matt] ( orbit1 & t no relation%ip subsi/s betwe5 ! size & physical features ( a ,comet & ! pa? x pursues 9 space4 ,! only sort ( res]vation1 p]haps1 to be made to ?is /atem5t is1 t ! comets celebrat$ = _! size & brilliancy1 are (t5 f\nd to be revolv+ 9 elliptic orbits ( great ecc5tricity1 :i* means t _! p]iods may am\nt to _m c5turies4 ,x may be well to say some?+ n[ z to :at is ! ord9>y c>e] ( a comet1 s f> z visibility to u1 ! inhabitants ( ! ,e>?1 is conc]n$4 ,?\gh ?is might be illu/rat$ by ref]5ce to ! hi/ory ( _m comets1 p]haps !re is no "o m suitable = ! purpose ?an ,donati's ,comet ( #aheh4 ,9 =m] times1 :5 telescopes 7 few or non-exi/5t1 brilliant comets (t5 appe>$ v sudd5ly1 j z a c>riage or a man does1 z y turn ! corn] ( a /reet4 ,su* ?+s ev5 happ5 /ill3 = in/ance1 ! great comet ( #ahfa bur/ ^u u all at once at a day's notice4 ,usually1 h[ev]1 n[ 9 consequ5ce ( ! l>ge size ( ! telescopes 9 use1 & ! great numb] ( obs]v]s :o are incessantly on ! wat*1 comets are discov]$ :5 !y are v small1 because remote bo? f ! ,e>? & ,sun1 & _m weeks1 or ev5 mon?s1 x may be1 be=e !y %9e =? 9 _! ultimate spl5d\r4 ,n[1 let u see h[ ^! /atem5ts are support$ by ! hi/ory ( ,donati's comet 9 #aheh4 ,on ,june #b 9 t ye>1 x 0 fir/ se5 by ,donati at ,flor5ce1 z a fa9t nebulosity1 sl[ly j\rney+ nor?w>ds4 ,june pass$ away1 & ,july1 & ,augu/1 ! comet all ! :ile rema9+ invisible to ! nak$ eye2 t is to say1 x fir/ became p]ceptible to ! nak$ eye on ,augu/ #bi1 hav+ put =? a fa9t tail ab\t ,augu/ #bj4 ,aft] ! beg9n+ ( ,septemb] its brilliancy rapidly increas$4 ,on ,septemb] #ag1 ! head equall$ 9 brightness a #bnd magnitude />1 ! tail be+ #d long4 ,pass+ its po9t ( ne>e/ approa* to ! ,sun on ,septemb] #bi1 x came ne>e/ to ! ,e>? on ,octob] #aj2 ?\gh1 p]haps1 its appe>ance a few days previ\sly1 namely on ,octob] #e1 is ! ?+ be/ rememb]$ by ^? :o saw x1 because x 0 on t night t ! comet pass$ ov] ! #a/ magnitude /> ,arcturus4 ,= sev]al days ab\t ?is "t1 ! comet 0 an object ( /rik+ beauty 9 ! ,we/]n ,heav5s1 dur+ ! h\rs imm$iately aft] sun-set4 ,aft] ,octob] #aj1 x rapidly pass$ away to ! ,s\!rn hemisph]e1 dim9i%+ 9 brightness1 z x did s1 because rec$+ f ! ,e>? & ! ,sun4 ,x cont9u$ its c>e] ?r\gh ! w9t]2 became invisible to ! nak$ eye2 & f9ally invisible altoge!r 9 ,m>* #ahei4 ,x rema9$ 9 view1 !re=e1 = m ?an n9e mon?s1 n to return aga9 till ab\t ! ye> #caeh ,a4,d41 = its p]iod ( revolution 0 f\nd to be ab\t #bjjj ye>s4 ,i h be5 p>ticul> 9 sket*+ some:at fully ! hi/ory ( ?is comet s f> z we are conc]n$1 because1 z ,i h already said1 x is typical ( ! visible c>e] ( _m comets4 ,halley's comet 9 #ahce & #ahcf1 w5t ?r\gh a some:at simil> s]ies ( *anges4 ,?is comet--a well-kn[n p]iodical "o ( great hi/oric int]e/ & brilliancy--may be comm5d$ to ! y\ng] memb]s ( ! ris+ g5]ation1 because x is due to return aga9 to ^! p>ts ( space a few ye>s h5ce1 or 9 #aiaj4 ,illu/ration3 ,fig4 #be4--,saw]?al's ,comet1 ,june #d1 #ahhh 7,*>lois74 ,:at is a comet made (8 ,m5 ( ,sci5ce equally ) ! g5]al public w\ld l to be able to answ] ?is "q1 b !y _c d s ) satisfactory c]ta9ty4 ,a great _m ye>s ago ,sir ,john ,h]s*el wrote ?us3--8,x seems impossible to avoid ! foll[+ conclusion1 t ! matt] ( ! nucleus ( a comet is p[]fully excit$ & dilat$ into a vapor\s /ate by ! action ( ! ,sun's rays escap+ 9 /reams & jets at ^? po9ts ( its surface :i* oppose ! lea/ resi/ance1 & 9 all probability ?r[+ t surface or ! nucleus itself into irregul> motions by its reaction 9 ! act ( s escap+1 & ?us alt]+ its direction40 ,?is passage 0 writt5 ( c\rse be=e ! spectroscope _h be5 br\ght to be> on ! obs]vations ( comets1 b s f> z ,sir ,john ,h]s*el's rem>k implies ! pres5ce ( vap\r1 t is gas1 9 a comet1 ! surmise has be5 amply borne out by lat] discov]ies4 ,! fact t z a comet approa*es ! ,sun "s =ces1 no d\bt ( sol> orig91 come into op]ation to vaporise & !re=e exp& ! matt] compos+ ! comet is suffici5tly %[n by ! great developem5t :i* takes place z we h se5 9 ! tails ( comets1 b 9 reg>d to ! heads ( comets we are face to face ) a /range enigma4 ,?\gh ! tails exp& ! heads contract z ! comet approa*es its position ( greate/ proximity to ! ,sun4 ,hav+ pass$ ?is po9t ! head exp&s aga94 ,?is curi\s circum/ance1 fir/ po9t$ out by ,kepl] 9 #afah1 has (t5 be5 notic$ s9ce1 & notic$ inde$ n z ! result ( m]e eye impressions1 b aft] c>eful micrometrical measurem5t ) suitable in/rum5ts4 ,i ?9k ! confession mu/ be made t we are hopelessly ignorant ( ! nature ( comet's except t gases are l>gely conc]n$ 9 _! con/itution4 ,x seems impossible to d\bt t "s tails ( comets are holl[ cyl9d]s or holl[ cones4 ,su* a !ory w\ld acc\nt = ! fact1 s (t5 notic$1 t s+le tails are usually mu* bright] at _! two edges ?an at ! c5tre4 ,?is is ! natural effect ( look+ transv]sely at any transluc5t cyl9d] ( measureable ?ickness4 ,x 0 long a moot po9t :e!r comets are self-lum9\s1 or :e!r !y %9e by reflect$ light2 b x is n[ g5]ally admitt$ t :il/ a "p ( ! light ( a comet may be d]iv$ by reflection f ! ,sun yet z a rule !y mu/ be reg>d$ z %9+ by _! own intr9sic light4 ,x %\ld be /at$ "h by way ( caution t ! obs]vations on ?is subject are n s consi/5t z "o c\ld wi%1 & x seems necess>y to assume t all comets are n con/itut$ alike1 & t !re=e :at is true ( "o does n necess>ily apply to ano!r4 ,to ^? :o possess telescopes 7n necess>ily l>ge ones7 opportunities = ! /udy ( comets h mu* multipli$ dur+ ! la/ few ye>s1 = we are n[ acqua9t$ ) a gr\p ( small comets :i* are con/antly com+ into view at %ort int]vals ( "t4 ,! comets h n[ become s num]\s t seldom a ye> passes )\t "o or m ( !m com+ into view4 ,:il/ t kn[n z ,encke's revolves r\nd ! ,sun 9 #c ye>s1 ,tuttle's do+ ! same 9 #ac ye>s1 !re are f\r o!rs ^: p]iods av]age ab\t #e ye>s1 #e :i* av]age #f ye>s1 toge!r ) "o ( #g ye>s & "o ( #h ye>s4 ,x is ?us evid5t t !re is a con/ant succession ( ^! objects available = /udy1 & t v few mon?s c ev] elapse t "s "o or m ( !m are n on view4 ,!y be> ! names ( ! a/ronom]s :o ei!r discov]$ !m orig9ally1 or :o1 by /udy+ _! orbits1 discov]$ _! p]iodicity4 ,! names run z foll[s1 beg9n+ ) ! %orte/ 9 p]iod & end+ ) ! longe/3-- ,encke's4 ,w9necke's4 ,temple's ,second 7#ahgc1 ,,ii47 ,brors5's4 ,temple's ,fir/ 7#ahfg1 ,,ii47 ,swift's 7#ahhj1 ,v47 ,wolf's 7#ahhd1 ,,iii47 ,b>n>d's 7#ahhd1 ,,ii47 ,faye's4 ,d',arre/'s4 ,d5n+'s4 ,f9lay's4 ,tuttle's4 ,i _c /ay to dwell ^u ei!r ! hi/ory or description ( ^! comets sep>ately1 b mu/ cont5t myself by say+ g5]ally t :il/ z a rule !y are n visible to ! nak$ eye1 yet sev]al ( !m may occasionally become s visible :5 !y return to p]ihelion "u circum/ances :i* br+ !m m ne> ?an usual to ! e>?4 ,sev]al o!r comets are on record :i* x 0 suppos$ at "o "t w\ld c]ta9ly h be5 entitl$ to a place 9 ! above li/1 b ?ree ( !m 9 p>ticul> h1 "u v my/]i\s circum/ances1 entirely disappe>$ f ! ,heav5s4 ,*ief among/ ! my/]i\s comets mu/ be rank$ t :i* goes by ! "n ( ,biela4 ,?is comet1 fir/ se5 9 #aggb1 0 aft]w>ds f\nd to h a p]iod ( ab\t #f ye>s1 & on num]\s occasions x reappe>$ at int]vals ( t l5g? d[n to #ahde1 :5 ! my/]i\s "p ( its c>e] seems to h comm5c$4 ,9 ,decemb] ( t ye> ?is comet ?rew (f a fragm5t ( ne>ly ! same %ape z itself1 & ! two portions travell$ toge!r side by side = f\r mon?s1 ! di/ance betwe5 ! fragm5ts sl[ly increas+4 ,at ! end ( ! f\r mon?s 9 "q ! comet pass$ out ( sight ow+ to ! di/ance f ! e>? to :i* x _h atta9$4 ,! comet return$ aga9 to p]ihelion 9 #aheb1 rema9+ visible = ?ree weeks4 ,! two portions ( ! comet notic$ 9 #ahdf reta9$ _! individuality 9 #aheb1 b ! di/ance betwe5 !m _h increas$ to ab\t eight times ! greate/ di/ance notic$ 9 #ahdf4 ,z a comet ,biela's ,comet has nev] be5 se5 s9ce #aheb1 & x mu/ n[ be reg>d$ z hav+ p]man5tly disappe>$4 ,b :at seems to h happ5$ is ?is1 t ,biela's ,comet has become brok5 up into a mass ( meteors4 ,on ,novemb] #bg1 #ahgb1 & aga9 9 ,novemb] #ahhe1 :5 ! e>? 9 travell+ along its own orbit rea*$ a c]ta9 po9t :]e its orbit int]sect$ ! =m] orbit ( ,biela's ,comet ! ,e>? enc\nt]$1 in/ead ( ! comet :i* ought to h be5 !re1 a wond]ful mass ( meteors2 & x is n[ g5]ally accept$ t ^! meteors1 :i* app>5tly are keep+ m or less toge!r z a fairly compact sw>m1 are n\ght else ?an ! dis9tegrat$ mat]ials ( :at once 0 ,biela's ,comet4 ,illu/ration3 ,fig4 #bf4--;,biela's ,comet1 ,febru>y #ai1 #ahdf4 ,x is extremely probable t z "t goes on we %all be able to say t an intimate connection subsi/s betwe5 p>ticul> comets :i* h be5 & p>ticul> meteoric sw>ms4 ,we already possess pro( t o!r comets :i* once came )9 our view 7 at t "t revolv+ r\nd ! ,sun 9 orbits s comp>atively small t !y %\ld h reappe>$ at int]vals ( half-a-doz5 or s ye>s1 yet !y h n reappe>$4 ,! "q !re=e sugge/s itself1 ,h !y be5 subject to "s great int]nal disa/] :i* has l$ to _! dis9tegration8 ,x may be said )\t d\bt t ?is is 9 ! highe/ degree probable2 b %ort ( ?is1 t is %ort ( total dis9tegration into small fragm5ts1 we h sev]al cases on record ( :at ,i may1 = ! mom5t1 call ord9>y comets break+ up into two or ?ree fragm5ts4 ,= a long :ile a/ronom]s 7 naturally loa? to believe t ?is 0 possible1 & !re=e !y discr$it$ ! /atem5ts to t effect :i* _h be5 made4 ,?\gh x w\ld occupy too mu* space to give ! p>ticul>s ( ^! comets 9 full x may yet be wor? :ile j to m5tion ! names ( "s ( !m1 presum$ to be ( %ort p]iod1 :i* seem$ nev]!less to h elud$ our grasp4 ,i w\ld "h specially m5tion ,liais's ,comet ( #ahfj & ! second comet ( #ahha z seem+ly hav+ und]gone "s sort ( disruption ak9 to :at happ5$ 9 ! case ( ,biela's ,comet4 ,!re is ano!r gr\p ( p]iodical comets to be m5tion$4 ,^! are six 9 numb] & seem to h p]iods ( #gj ye>s or a little m4 ,( ^! ?ree h n yet giv5 u ! *ance ( see+ !m aga92 two h paid u a second visit1 & !re=e _! p]iods are n op5 to d\bt2 :il/ ! mo/ fam\s ( ?is gr\p1 8,halley's10 has be5 record$ to h %[n itself to ! ,e>? no less ?an #be times1 beg9n+ ) ! ye> #aa ,b4 ,c4 ,x 0 ,halley's comet :i* %one ov] ,europe 9 ,april #ajff1 & 0 consid]$ ! =]unn] ( ! conque/ ( ,engl& by ,william ( ,norm&y4 ,x figures 9 ! fam\s ,bayeux tape/ry z a hairy /> ( /range %ape4 ,x w\ld seem t !re exi/s 9 "s inscrutable mann] a connection betwe5 ea* ( ! ?ree great ext]ior planets & c]ta9 gr\ps ( comets4 ,9 ! case ( ,jupit] ! association is s v pron\nc$ z long ago to h attract$ notice2 b ! ,fr5* a/ronom]1 ,flamm>ion1 has br\ght =w>d "s sugge/ions t ,saturn has "o comet 7& p]haps two7 ) :i* x is associat$2 ,uranus1 two 7& p]haps ?ree72 & ,neptune1 six2 :il/ f>!r (f ?an ,neptune ! fact t !re are two comets1 suppos$ p]iodical1 )\t a kn[n planet to run ) !m has inspir$ ,flamm>ion to look ) a fri5dly eye on ! idea 7(t5 moot$7 t outside ( ,neptune !re exi/s ano!r undiscov]$ planet revolv+ r\nd ! sun 9 a p]iod ( ab\t #cjj ye>s4 ,! ,jupit] gr\p ( comets des]ves a few additional words4 ,!re are c]ta9ly n9e1 & p]haps twelve comets revolv+ r\nd ! ,sun 9 orbits ( su* dim5sions t !y ei!r rea* up to or slightly ov]rea* ! orbit ( ,jupit]4 ,! effect ( ?is condition ( ?+s is t on occasions ,jupit] & ea* ( ! comets may come into su* proximity t ! sup]ior mass ( ,jupit] may ex]cise a v s]i\sly di/urb+ influ5ce ov] a flimsy & e!real body l a comet4 ,!re is reason to suppose t "s ( ! comets n[ belong+ to ! ,jupit] gr\p h n done s = any great l5g? ( "t1 b hav+ be5 w&]+ ab\t1 ei!r 9 elliptic orbits ( great ext5t1 or ev5 9 p>abolic orbits1 h accid5tally come )9 rea* ( ,jupit]1 & s h be51 z x 71 captur$ by him4 ,h5ce1 ! orig9 ( ! t]m1 ! 8capture !ory10 z appli$ to ^! family gr\ps ( comets :i* ,i h j /at$ to exi/1 ea* presid$ ov]1 z x 71 by a great planet4 ,x may be t at "s future "t ?is !ory w help u to a clue to ! fact t besides ! comets ( ,lexell ( #aggj1 ,bla9pa9 ( #ahai1 & ,di ,vico ( #ahdd1 %ort p]iod comets unacc\ntably miss+1 !re are sev]al o!rs presum$ to h be5 revolv+ 9 %ort p]iod orbits :5 discov]$1 & z to :i* x is v /range t !y %\ld n h be5 se5 be=e _! only record$ visit to u1 & equally /range t !y %\ld nev] h be5 se5 s9ce4 ,is !re any reason to fe> ! results ( a collision betwe5 a comet & ! ,e>?8 ,none :atev]4 ,h[ev] vague may be1 & 9 a c]ta9 s5se mu/ be1 our answ] to ! "q1 8,:at is a comet80 c]ta9 is x t e comet is a v impond]able body--a sort ( airy no?+1 a mass ( gas or vap\r4#f ,at ! same "t x always has be5 & p]haps /ill is difficult to p]suade ! public t :atev] might be ! effect on a comet if x 7 to /rike ! ,e>?1 ! effect on ! ,e>?1 7 x to be /ruck by a comet1 w\ld be nil4 ,?is is n altoge!r a matt] ( speculation1 = accord+ to a calculation by ,h9d1 on ,june #cj1 #ahfa1 ! ,e>? pass$ into & ?r\gh ! tail ( ! great comet ( t ye> at ab\t two-?irds ( its di/ance f ! nucleus4 ,assur$ly !re 0 no dynamical result2 b x seems1 h[ev]1 n unlikely t !re 0 an optical result2 at any rate1 traces ( some?+ ( ?is sort 7 not$4 ,h9d himself1 9 ,middlesex1 obs]v$ a peculi> phosphoresc5ce or illum9ation ( ! sky :i* he attribut$ at ! "t to an auroral gl>e4 ,l[e1 9 ,nott+ham%ire confirm$ ,h9d's /atem5t ( ! appe>ance ( ! heav5s on ! same day4 ,! sky _h a yell[ auroral gl>e-l look1 & ! ,sun1 ?\gh %9+1 gave b feeble light4 ,! comet 0 pla9ly visible at #g4de p4 m4 7dur+ sun%9e71 & _h a mu* m hazy appe>ance ?an on any subsequ5t ev5+4 ,l[e adds t 8 ,vic> _h ! pulpit c&les light$ 9 ! ,p>i% ,*ur* at #g o'clock 7x 0 a ,sunday71 ?\gh only five days _h elaps$ s9ce ,midsumm] day1 :i* itself proves t "s s5sation ( d>kness 0 felt ev5 :ile ! ,sun 0 %9+4 ,s f> z ,i rememb] !re has be5 no su* ?+ z a comet panic dur+ ! pres5t g5]ation1 at any rate 9 civilis$ c\ntries1 b x is on record t !re 0 a v consid]able panic 9 #ahcb 9 connection ) ! return ( ,biela's ,comet 9 ! w9t] ( t ye>4 ,olb]s z ! result ( a c>eful /udy 9 advance ( ! comet's movem5ts f\nd t ! comet's c5tre w\ld pass only #bj1jjj miles )9 ! ,e>?'s orbit1 & t z ! nebulosity ( ! comet _h 9 #ahje be5 m ?an #bj1jjj miles 9 diamet]1 x 0 c]ta91 unless its dim5sions _h dim9i%$ 9 ! #bg ye>s1 t "s ( ! comet's matt] w\ld ov]lap ! ,e>?'s orbit2 9 o!r words w\ld envelop ! ,e>? itself1 if ! ,e>? happ5$ to be !re4 ,?is conclusion :5 x became public 0 q en\gh to create a panic & make p talk ab\t ! =?com+ de/ruction ( our globe4 ,x 0 no?+ to ! po9t 79 ! public m9d7 t a/ronom]s 7 able to pr$ict t ! ,e>? w\ld n rea* ! place :]e ! comet w\ld cross ! ,e>?'s orbit until f\r weeks aft] ! comet _h come & gone4 ,h[ev]1 we n[ "k t no?+ happ5$1 & ,i am ju/ifi$ 9 add+ t ev5 if !re _h be5 contact1 ,e>? meet+ comet face to face1 no?+ 7s]i\s7 w\ld h occurr$ s f> z ! ,e>? 0 conc]n$4 ,?is seems a conv5i5t place = ref]r+ to a matt] :i* :5 x 0 fir/ broa*$ excit$ a great deal ( int]e/1 b ab\t :i* "o does n he> mu* n[-a-days4 ,! p]iod ( ! small comet kn[n z ,encke's 7:i*1 revolv+ z x does r\nd ! ,sun 9 a little m ?an ?ree ye>s1 has ! %orte/ p]iod ( any ( ! p]iodical comets7 0 f\nd _m ye>s ago to be dim9i%+ at ea* successive return4 ,t is to say1 x always atta9$ its ne>e/ di/ance f ! ,sun at ea* app>ition #b h\rs soon] ?an x ought to h done4 ,9 ord] to acc\nt = ?is gradual dim9ution 9 ! comet's p]iod ,encke conjectur$ ! exi/5ce ( a ?9 e!real m$ium suffici5tly d5se to affect a light flimsy body l a comet1 b incapable ( ob/ruct+ a planet4 ,x has be5 rem>k$ by ,h9d t 8?is contraction ( ! orbit mu/ be cont9ually progress+1 if we suppose ! exi/5ce ( su* a m$ium2 & we are naturally l$ to inquire1 ,:at w be ! f9al consequ5ce ( ?is resi/ance8 ,?\gh ! cata/rophe may be av]t$ = _m ages by ! p[]ful attraction ( ! l>g] planets1 especially ,jupit]1 w n ! comet be at la/ precipitat$ on ! ,sun8 ,! "q is full ( int]e/1 ?\gh altoge!r op5 to conjecture40 ,a/ronom]s are n altoge!r agre$ z to ! propriety ( ?is explanation4 ,"o argum5t aga9/ x is t ) p]haps "o exception none ( ! o!r %ort-p]iod comets 7all ( !m small & presumably defici5t 9 d5sity7 seem affect$ z ,encke's is4 ,on ! o!r h& ,sir ,john ,h]s*el fav\r$ ! explanation j giv51 z also does ,h9d :o is ! highe/ liv+ au?ority on comets4 ,a ,g]man ma!matician1 ,von ,a/51 :o devot$ imm5se lab\r to ! /udy ( ! orbit ( ,encke's ,comet1 ?\ght !re %\ld be no hesitation 9 accept+ ! idea ( a resi/+ m$ium1 subject to ! limitation t x does n ext5d beyond ! orbit ( ,m]cury4 ,von ,a/5's allusion to ,m]cury t\*es a subject :i* belongs m directly to ! "q ( ,m]cury's orbit & to t o!r v int]e/+ "q1 8,are !re any planets1 n at pres5t kn[n1 revolv+ r\nd ! ,sun )9 ! orbit ( ,m]cury40 ,:i* is ! l>ge/ & mo/ magnific5t comet record$ 9 hi/ory8 ,x is virtually impossible to answ] ?is "q1 because ( ! extravagant & inflat$ language made use ( by anci5t & m$ieval 7,i _h almo/ add$1 & mod]n7 writ]s4 ,!re is no d\bt t ! comet ( #afhj1 /udi$ by ,sir ,i4 ,newton1 ! tail ( :i* 0 curv$1 & f #gj to #ij long1 mu/ h be5 "o ( ! f9e/ on record1 z x 0 also ! "o :i* came ne>e/ to ! ,sun1 = x almo/ graz$ ! ,sun's surface4 ,! comet ( #agdd1 visible z x 0 9 broad daylight1 01 no d\bt1 ! f9e/ comet ( ! #ah? c5tury1 ?\gh 9 size x has be5 surpass$2 yet its six tails mu/ h made x a mo/ rem>kable object4 ,s f> z ! #ai? c5tury is conc]n$1 our *oice lies betwe5 ! comets ( #ahaa1 #ahdc1 #aheh1 & #ahfa4 ,! comet ( #ahaa is spok5 ( by ,h9d z 8p]haps ! mo/ fam\s ( mod]n times4 ,indep5d5tly ( its great magnitude1 ! position ( ! orbit & epo* ( p]ihelion passage1 7 su* z to r5d] x a v spl5did circumpol> object = "s mon?s40 ,! tail z reg>ds its l5g? 0 n s v rem>kable1 = at its be/1 9 ,octob] #ahaa1 x 0 only ab\t #be long1 its bread?1 h[ev]1 0 v consid]able2 at "o "t #f1 ! real l5g? ( ! tail1 ab\t ! middle ( ,octob]1 0 m ?an #ajj1jjj1jjj ( miles1 & its bread? ab\t #ae1jjj1jjj ( miles4 ,! visibility ( ?is comet 0 co9cid5t ) ^? ev5ts :i* prov$ to be ! turn+-po9t 9 ! c>e] ( ,napoleon ,i41 & !re 7 n want+ ^? :o reg>d$ ! comet z a presage ( 8 disa/r\s failure 9 ,russia4 ,ow+ to ! long p]iod 7#ag mon?s71 dur+ :i* ?is comet 0 visible1 x 0 possible to det]m9e its orbit ) unusual precision4 ,argel&] f\nd its p]iod to be #cjfe ye>s1 ) no great] unc]ta9ty ?an #dc ye>s4 ,! great dim5sions ( its orbit w be realis$ :5 x is /at$ t ?is comet rec$es f ! ,sun to a di/ance ( #ad times t ( ! planet ,neptune4 ,illu/ration3 ,fig4 #bg4--,! ,great ,comet ( #ahaa4 ,donati's comet ( #aheh1 has already receiv$ a good deal ( notice at my h&s1 b ! "q rema9s1 :at are its claims1 to be reg>d$ z ! comet ( ! c5tury1 comp>$ ) t ( #ahdc8 ,x is n a little /range t ?\gh !re mu/ h be5 _m p]sons :o saw bo?1 yet x 0 only q rec5tly t ,i came across1 = ! fir/ "t1 a description ( bo? ^! comets f ! same p54 ,x ought1 h[ev]1 to be m5tion$ by way ( explanation1 t ! inhabitants ( ,europe only saw ! comet ( #ahdc1 :5 its brilliancy & ! ext5t ( its tail _h mat]ially dim9i%$1 ab\t a =tnight aft] x 0 at its be/4 ,! description ( ^! two comets to :i* ,i h allud$1 w be f\nd 9 ,g5]al ,j4 ,a4 ,ew>t's 8,/ory ( a ,soldi]'s ,life10 publi%$ 9 #ahha4 ,writ+ fir/ ( all ( ! comet ( #ahdc1 ,g5]al ,ew>t says3-- 8,x 0 dur+ our passage f ! ,cape ( ,good ,hope to ! ,equator1 & :5 n f> f ,/4 ,hel5a1 t we fir/ came 9 sight ( ! great comet ( #ahdc4 ,9 ! fir/ in/ance a small portion ( ! tail only 0 visible1 at "r angles to ! horizon2 b night aft] night z we sail$ along1 x gradually became l>g] & l>g]1 till at la/ up came ! head1 or nucleus1 z ,i ought prop]ly to call x4 ,x 0 a gr& & wond]ful sight1 = ! comet n[ ext5d$ ! extraord9>y di/ance ( "o-?ird ( ! heav5s1 ! nucleus be+1 p]haps1 ab\t ! size ( ! planet ,v5us40--7,vol4 i41 p4 #ge47 ,illu/ration3 ,fig4 #bh4--,! ,great ,comet ( #ahhb1 on ,octob] #ai 7,artus74 ,z reg>ds ,donati's comet ( #aheh1 :at ! ,g5]al says is3-- 8,a v l>ge comet made its appe>ance ab\t ?is "t1 & cont9u$ = sev]al weeks to be a magnific5t object at night2 x 01 h[ev]1 no?+ to ! "o ,i _h se5 9 ! ye> #ahdc1 :5 on ! o!r side ( ! equator40--7,vol4 ii41 p4 #bje47 ,pass+ ov] ! great comet ( #ahfa1 on :i* ,i h already said a good deal1 ,i mu/ quit ! subject ( fam\s comets by a few words ab\t t ( #ahhb1 :i*1 ?\gh by no means "o ( ! l>ge/1 01 9 "s respects1 "o ( ! mo/ rem>kable ( mod]n times4 ,x 0 visible = ! long p]iod ( n9e mon?s1 & 0 conspicu\sly prom95t to ! nak$ eye dur+ ,septemb]1 b ^! facts1 ?\gh note-wor?y1 w\ld n h call$ = p>ticul> rem>k1 _h n ! comet exhibit$ "s special peculi>ities :i* di/+ui%$ x f all o!rs4 ,9 ! fir/ place1 x seems to h und]gone c]ta9 disruptive *anges1 9 virtue ( :i* ! nucleus became split up into f\r indep5d5t nuclei4 ,!n ! tail may h be5 tubul>1 its extremity be+ n only bifid1 b totally unsymmetrical ) respect to ! ma9 "p4 ,! tubul> "* ( ! tail 0 sugge/$ by ,tempel4 ,to o!r obs]v]s1 ?is feature gave ! idea ( ! comet1 prop]ly s-call$1 be+ enclos$ 9 a cyl9drical envelope1 :i* completely surr\nd$ ! comet1 & ov]lapp$ x = a consid]able di/ance at bo? ends4 ,f9ally 7& 9 ?is resembl+ ,biela's comet7 ! comet ( #ahhb seems to h ?r[n (f a fragm5t :i* became an indep5d5t body4 ,:at has gone be=e1 w1 ,i ?9k1 h s]v$ abundantly to e/abli% ! position ) :i* ,i />t$1 namely1 t comets occupy 7& des]v$ly s7 ! front rank among/ ^? a/ronomical objects 9 :i*1 on occasions1 ! g5]al public takes an int]e/4 ,i h ?us complet$1 s f> z ! space at my disposal has p]mitt$1 a popul> descriptive ,survey ( ! ,sol> ,sy/em4 ,^? :o h p]us$ ! prec$+ pages1 h[ev] slight may h be5 _! previ\s acqua9tance ) ! ,sci5ce ( ,a/ronomy tak5 z a :ole1 w h no difficulty 9 realis+ t :at ,i h said be>s b a small proportion to :at ,i h left unsaid4 ,!y w equally1 ,i hope1 be able to see1 )\t inde$ ! necessity ( a sugge/ion1 t all ^? wondr\s orbs :i* we call ! planets c\ld nei!r h come into exi/5ce nor h be5 ma9ta9$ 9 _! allott$ places = s _m ?\s&s ( ye>s1 except z ! result ( ,design emanat+ f an ,all-p[]ful ,creator4 ,,footnotes4 #a,! rem>k 9 ! text applies to all ! major planets & to a l>ge numb] ( ! m9or planets1 b c]ta9 ( ! m9or planets travel 9 orbits :i* are consid]ably incl9$ to ! ecliptic1 & !re=e to all ! o!r planets4 #b;,giv5 9 full 9 my ,h&book ( ,a/ronomy1 #d? ed41 vol4 i41 p4 #bf4 #c8,recollections ( ,pa/ ,life10 #bnd ed41 p4 #cje4 #d;,= "s in=mation respect+ ^! ,sec*i 8,types0 ( ,/>s1 see my 8,/ory ( ! ,/>s10 #bnd ed41 p4 #adj4 #e,! circle & ! ellipse are :at are call$ 8clos$0 curves4 #f;,x is n a little s+ul> t ! ,*9ese 9 bygone c5turies h (t5 allud$ to comets "u ! "n ( vap\rs2 e4g41 ! comet ( #afah is record$ z hav+ be5 8a :ite vap\r #bj cubits long40 ,,app5dix4--,,tables ,,( ,,! ,,sol> ,,sy/em4 ,,! ,,sun ,,& ,,planets4 ,"n4 ,sid]eal ,mean ,diamet]4 ,surface4 ,volume4 ,mass4 ,d5sity4 ,axial ,=ce ( ,velocity p]iod4 di/ance ,miles4 ,e>?#a4 ,e>?#a4 ,e>?#a4 ,e>?#a4 ,rotation4 gravity4 9 orbit4 f d4 h4 m4 ,fall3 ,miles p] ,sun4 ,ft4 9 #a h\r ,millions sec4 ( miles4 ,,sun 44444 44444 #hff1bjj #aa1idf #a1cje1jjj #ccb1jjj #j4be #be #g #dh #dfa h4 m4 s4 ,,m]cury #hh days4 #cf #c1jjh #j4add #j4jee #j4jff #a4bf #bd #e #cj #g #ajg1jjj ,,v5us #bbe #fg #g1dhj #j4hia #j4hda #j4ghb #j4ib #bc #ba #bc #ad #gh1jjj ,,e>? #cfe #ic #g1ibf #a4jjj #a4jjj #a4jjj #a4jj #bc #ef #d #af #ff1jjj ,,m>s #fhg #ada #e1jjj #j4cih #j4bea #j4ajg #j4de #bd #cg #bc #d #ec1jjj ,m9or ,planets ,eros 7#dcc7 #a4gf 44444 #ah ,eros is ! ne>e/ to ! ,sun ( ! ,m9or ,planets1 "p ye>s4 ( its orbit fall+ betwe5 ! ,e>? & ,m>s4 ,ve/a 7#d7 #c4f #bai #bad ,ve/a is ! l>ge/ ( ! ,m9or ,planets4 ,?ule 7#bgi7 #h4h #cif 44444 ,?ule is ! mo/ di/ant f ! ,sun ( ! ,m9or ,planets4 ,,jupit] #aa4h #dhc #hh1dci #abd #a1chi #cag #j4bc #i #ee #ba #da #bi1jjj ,,saturn #bi4d #hhf #ge1jcf #hi #hdh #id #j4aa #aj #bi #ag #ah #ba1jjj ,,uranus #hd4j #aghb #cj1hge #ae #ei #ad #j4be 8 #ac #ae1jjj ,,neptune #afd4f #bgib #cg1bje #ba #ajc #ag #j4ag 8 #ab #ab1jjj ,,satellite ,,( ,,! ,,e>?4 ,"n4 ,sid]eal ,di/ance ,diamet] ,surface4 ,volume4 ,mass4 ,d5sity4 ,axial ,=ce ( ,velocity p]iod4 f ,miles4 ,e>?#a4 ,e>?#a4 ,e>?#a4 ,e>?#a4 ,rotation4 gravity4 9 orbit4 d4 h4 m4 ,e>?4 d4 h4 m4 ,fall3 ,miles p] ,miles4 ,feet 9 h\r4 #a sec4 ,,moon #bg #g #dc #bcg1cjj #b1afj #j4jgd #j4jbjcd #j4jabh #j4fc #bg #g #dc #b4dh #b1bgc ,,satellites ,,( ,,m>s4 ,"n4 ,discov]]4 ,mean ,sid]eal ,diamet]4 ,maximum ,app>5t di/ance p]iod4 ,miles4 elongation4 /> f d4 h4 m4 magnitude4 ,m>s4 ,miles4 #a4 ,,phobos ,a4 ,hall1 ,augu/ #f1jjj #j #g #ci #g #ab #aa #ag1 #ahgg4 #b4 ,,deimos ,a4 ,hall1 ,augu/ #ae1jjj #a #f #ah #f #cb #ac #aa1 #ahgg4 ,,satellites ,,( ,,jupit]4 ,"n4 ,discov]]4 ,mean ,sid]eal ,diamet]4 ,app>5t ,app>5t di/ance p]iod4 ,miles4 diamet] /> f d4 h4 m4 ( ,jupit] magnitude4 ,jupit]4 se5 f ,miles4 satellite4 #e4 ,b>n>d 4444444 #j #aa #di 8 44444 4444 #a4 ,,io 444444444444444 #bfg1jjj #a #ah #bi #b1cij #ai #di #g #b4 ,,europa ,galileo1 ,janu>y #dbe1jjj #c #ac #ac #b1abj #ab #be #g #g-ac1 #afaj4 #c4 ,,ganym$e 444444444444444 #fgh1jjj #g #d #j #c1ihj #g #dg #f #d4 ,,calli/o 444444444444444 #a1aib1jjj #af #ah #e #b1igj #d #be #g ,,satellites ,,( ,,saturn4 ,"n4 ,discov]]4 ,mean ,sid]eal ,diamet]4 ,app>5t ,app>5t di/ance p]iod4 ,miles4 diamet] /> f d4 h4 m4 ( ,saturn magnitude4 ,saturn4 se5 f ,miles4 satellite4 #a4 ,,mimas ,sir ,w4 ,h]s*el1 #aae1jjj #j #bb #cg #a1jjj #cc #ag ,sept1 #ag1 #aghi #b4 ,,enceladus ,aug4 #bh1 #aghi #adg1jjj #a #h #ec 8 #bf #ae #c4 ,,te?ys ,j4 ,d4 ,cass9i1 #ahc1jjj #a #ba #ah #ejj #ba #ac ,m>*1 #afhd #d4 ,,dione ,m>*1 #afhd #bcd1jjj #b #ag #da #ejj #af #ab #e4 ,,rhea ,dec4 #bc1 #afgb #cbg1jjj #d #ab #be #a1bjj #ab #aj #f4 ,,titan ,huyg5s1 ,m>4 #be1 #geh1jjj #ae #bb #da #c1cjj #e #h #afec #g4 ,,hyp]ion ,w4 ,bond #iaf1jjj #ba #g #g 8 #d #ag ,lassell1 ,sept1 #ai1 #ahdh #h4 ,,iapetus ,j4 ,d4 ,cass9i1 #b1bba1jjj #gi #g #ec #a1hjj #b #i ,oct4 #be1 #afga ,,satellites ,,( ,,uranus4 ,"n4 ,discov]]4 ,mean di/ance ,sid]eal ,maximum f ,uranus4 p]iod4 elongation4 ,miles4 d4 h4 m4 #a4 ,,ariel ,lassell1 ,septemb] #abd1jjj #b #ab #bh #ab #ad1 #ahdg #b4 ,,umbriel ,o4 ,/ruve1 ,octob] #h1 #agc1jjj #d #c #bg #ae #ahdg #c4 ,,titania ,sir ,w4 ,h]s*el1 #bhe1jjj #h #af #ee #cc ,janu>y #aa1 #aghg #d4 ,,ob]on #cha1jjj #ac #aa #f #dd ,,satellite ,,( ,,neptune4 ,discov]]4 ,mean di/ance ,sid]eal ,maximum ,app>5t f ,neptune4 p]iod4 elongation4 /> ,miles4 d4 h4 m4 magnitude4 ,lassell1 ,octob] #bbc1jjj #e #ba #h #ah #ad #aj1 #ahdf ,,g5]al ,,index4 ,a4 ,adams1 ,j4 ,c41 #ade4 ,airy1 ,sir ,g4 ,b41 #ade4 ,anagram on ,v5us1 #fh2 on ,saturn1 #abg4 ,aphelion1 #aa1 #ajb4 ,app>5t movem5ts ( ! ,planets1 #ab1 #ad4 ,arago1 ,d4 ,j4 ,f41 #ii1 #abd1 #adj4 ,arctic regions ( ! ,e>?1 #ge4 ,argel&]1 ,f4 ,g4 ,a41 #agh4 ,ari/>*us ( ,samos1 #ga4 ,ari/>*us 7,lun> ,m\nta971 #ic1 #id4 ,a/]oids1 #aaj4 ,aurora ,borealis & spots on ! ,sun1 #ee2 & tw9kl+1 #hg4 ,autumnal ,equ9ox1 #gd4 ,axial rotation ( ! ,planets1 #ag1 #ahc4 ,b4 ,b>n>d4 ,e4 ,e41 #abj1 #acd4 ,b>n>d's ,comet1 #afh4 ,bayeux ,tape/ry1 #aga4 ,be] & ,mdl]2 _! map ( ! ,moon1 #if4 ,belts on ,jupit]1 #aae1 #abc2 on ,saturn1 #abb4 ,b]g]on's ,exp]im5t1 #ic4 ,bessel1 ,w41 #abd4 ,biela's ,comet1 #afh4 ,bode's s-call$ 8,law10 #aaj4 ,bond1 ,g4 ,p41 #acb1 #acc4 ,b\v>d1 ,a41 #adc4 ,bradley1 ,rev4 ,j41 #add4 ,br$e*9's !ory ( ,tails ( ,comets1 #aeg4 ,brors5's ,comet1 #afg4 ,c4 8,canals0 on ,m>s1 #ajf4 ,c>p5t]1 ,j41 #acd4 ,c>r+ton1 ,r4 ,c41 #df1 #di4 ,cass9i1 ,j4 ,d41 #cf1 #aah1 #abh1 #acj1 #acf4 ,c]es 7,m9or ,planet71 #aab4 ,*allis1 ,rev4 ,j41 #adf4 ,*>ts1 ,cele/ial1 #aab1 #adg4 ,*9ese obs]vations1 #be1 #agb4 ,cl\ds influ5c$ by ! ,moon1 #ih4 ,coggia's ,comet1 #ahgd1 #aea4 ,comets1 #aej2 p]iodic1 #afb1 #agj2 rem>kable1 #agf4 ,comp>ative sizes ( ! ,planets1 #aa4 ,comp>ative size ( ! ,sun f ! ,planets1 #ag4 ,compression ( ! ,planets1 #gj1 #abb1 #acg4 ,conjunction ( ! ,planets1 #ad1 #ae1 #ff4 ,cop]nican ,sy/em1 #gb4 ,cop]nicus1 #gb1 #gc1 #gf4 ,d4 ,d',arre/1 #adg4 ,d',arre/'s ,comet1 #afh4 ,dawes1 ,w4 ,r41 #ajf1 #acc4 ,day & night1 #ab4 ,day1 l5g? (1 #gd4 ,de ,la ,rue1 ,w41 #ce1 #cf1 #di1 #eb4 ,d5n+'s ,comet1 #afh4 ,d5sity ( ! ,planets1 #ag1 #ahc4 ,diamet] ( ! ,sun & ,planets1 #ahc4 ,di ,vico1 #fb1 #fc4 ,di ,vico's ,comet1 #agb4 ,di/ance ( ! ,planets f ! ,sun1 #bj1 #ahc4 ,donati's ,comet ( #aheh1 #aeg1 #afc1 #agh4 ,duf\r on ,tw9kl+1 #hd4 ,e4 ,e>?1 annual motion (1 #ge2 figure (1 #gj4 ,e>?%9e1 #ff1 #ic4 ,ecc5tricity ( ,planet>y orbits1 #aj1 #fj1 #ge4 ,eclipses ( ! ,sun1 #ef1 #eg2 ( ! ,moon1 #abj4 ,ecliptic1 plane (1 #i1 #aj1 #gd4 ,egyptian ,sy/em1 #gb4 ,elliptic ,orbits1 #aj4 ,elongation ( ,planets1 #ad4 ,encke1 ,j4 ,f41 #adg4 ,encke's ,comet1 #afg1 #agd1 #age4 ,equ9oxes1 #gd4 ,ew>t1 ,g54 ,j4 ,a41 #agh4 ,f4 ,facul on ! ,sun1 #db1 #dc4 ,faye's ,comet1 #afh4 ,f9lay's ,comet1 #afh4 ,flamm>ion1 ,c41 #fb1 #ff1 #aga4 ,flam/e$1 ,rev4 ,j41 #adj1 #add4 ,g4 ,galileo1 #hi1 #aja1 #abj1 #abe4 ,galle1 ,j4 ,g41 #adg4 ,gass5di1 #gf4 ,geodesy1 #gj4 ,georgium ,sidus1 #ada4 ,golds*midt1 ,h41 #d4 ,granules1 ,sol>1 #ch4 ,gravity on ! ,sun & ,planets1 #ahc4 ,h4 ,hall1 ,a41 #aji4 ,halley's ,comet1 #afd1 #aga4 ,heat rays ( ! ,sun1 #bj2 ( ! ,moon1 #if4 ,h]s*el1 ,sir ,w41 #cd1 #dj1 #dd1 #eh1 #ajj1 #ajc1 #acd1 #acg1 #ach1 #adb4 ,h]s*el1 ,sir ,j4 ,f4 ,w41 #bd1 #if1 #ii1 #ajc1 #acb1 #age4 ,h9d1 ,j4 ,r41 #aai1 #agc1 #age4 ,hold51 ,e4 ,s41 #ajf4 ,holl&1 ,sir ,h41 #gh4 ,holmes's ,comet1 #ahib1 #aei4 ,hom]'s ,iliad1 cit$1 #fh4 ,h[lett1 ,rev4 ,f41 #dg4 ,hugg9s1 ,w41 #dj4 ,huyg5s1 ,c41 #abg1 #acj4 ,hyp]bola1 #afb4 ,hyp]bolic ,comets1 #afb4 ,i4 ,incl9ation ( planet>y orbits1 #i4 ,inf]ior ,planets1 #i1 #ab4 ,j4 ,janss5 ,j41 #dg4 ,juno 7,m9or ,planet71 #aab4 ,jupit]3 its influ5ce on ,sun-spots d\btful1 #ea1 #ec2 on ,comets1 #aga2 its light1 #g4 ,k4 ,kepl]1 #ee1 #abe1 #aff4 ,kew ,obs]vatory1 #dg4 ,l4 ,la ,hire1 #fc4 ,lal&e1 #cd4 ,lassell1 ,w41 #abc1 #adb1 #ahe4 ,l$g]1 ,rev4 ,e41 #hd4 ,le ,monni]1 #adj1 #add4 ,le ,v]ri]1 ,u4 ,j4 ,j41 #adg4 ,lexell's ,comet1 #agb4 ,liais's ,comet1 #agj4 ,logogriphs z to ,v5us1 #fh2 z to ,saturn1 #abg4 ,m4 ,mdl]1 ,j4 ,h41 #fc1 #if4 ,magnetism1 ,t]re/rial1 #ee4 ,maps1 ,a/ronomical1 #aab1 #adg4 ,m>s1 #ajj4 ,maskelyne1 ,rev4 ,n41 #aci4 ,mass ( ! ,sun1 & ( ! ,planets1 #bj1 #ahc4 ,m$ium1 ,resi/+1 #age4 ,m]cury1 #eg2 phases (1 #ae2 its influ5ce on ,sun-spots1 #ea2 its lum9osity1 #fg4 ,milton1 ,j41 ,p>adise ,lo/1 cit$1 #aec4 ,m9or ,planets1 #aaj4 ,montigny on ,tw9kl+1 #hd4 ,moon1 #hi4 ,moonlight1 ,brightness (1 #if4 ,motions ( ! ,planets1 #aj4 ,m\nta9s ( ! ,moon1 #ij4 ,n4 ,napoleon ,i41 #aed1 #agf4 ,nasmy?1 ,j41 #dj4 ,ne$le1 ,magnetic1 #ee4 ,neptune1 #adc2 its influ5ce on ,uranus1 #adc4 ,newton1 ,sir ,i41 #agf4 ,nubian aft]-gl[1 #hc4 ,nucleus ( a ,sun-spot1 #bb4 ,o4 ,obliquity ( ! ecliptic1 #gd4 ,occultations ( ,jupit]'s ,satellites1 #aba4 ,olb]s1 ,w41 #aab1 #agd4 ,opposition ( ,planets1 #ac4 ,orbits ( ! ,planets1 #i1 #aj2 ( ,comets1 #afa4 ,p4 ,pallas 7,m9or ,planet71 #aab1 #aac1 #aad4 ,p>abola1 #afb4 ,p5umbra ( a ,sun-spot1 #bb4 ,p]ihelion1 #aa1 #ajb4 ,p]iodic ,comets1 #afb1 #agj4 ,p]turbations ( ,uranus by ,neptune1 #ade4 ,phases ( an inf]ior ,planet1 #ae2 ( a sup]ior ,planet1 #af2 ( ,m>s1 #ajj2 ( ,jupit]1 #aae4 ,piazzi1 ,g41 #aaa4 ,planets1 classification (1 #g2 comp>ative sizes (1 #aa2 movem5ts (1 #aj4 ,plut>*1 #ga4 ,poles ( ,m>s1 sn[ at1 #ajd4 ,prim>y ,planets1 #g4 ,ptolemaic ,sy/em1 #gb4 ,q4 ,quadrature ( a ,planet1 #af4 ,qu5isset's ,comet1 #ahic1 #aef4 ,r4 ,rays ( ! ,sun1 #bj4 ,refraction1 #gg2 effect (1 #gg4 ,r$ spot on ,jupit]1 #aah4 ,resi/+ ,m$ium1 #age4 ,retrograde motion ( a ,planet1 #ae4 8,rice gra9s0 on ! ,sun1 #ci1 #dj4 ,r+s ( ,saturn1 #abh4 ,rosse1 ,e>l (1 #ic4 ,rotation ( ! ,sun1 #bd1 #bh2 ( ! planets1 #ag1 #ahc4 ,rotundity ( ! ,e>?1 #gf4 ,s4 ,satellites ( ,m>s1 #af1 #ahd2 ( ,jupit]1 #af1 #ahd2 ( ,saturn1 #af1 #ahe2 ( ,uranus1 #af1 #ahe2 ( ,neptune1 #af1 #ahe4 ,saturn1 #abb4 ,saw]?al's ,comet1 #afe4 ,s*iap>elli1 ,j4 ,v41 #ei1 #fb1 #fc1 #ajf4 ,s*midt1 ,j4 ,f4 ,f41 #if4 ,s*rt]1 ,j4 ,j41 #eh1 #fb1 #fc4 ,s*wabe's obs]vations ( ,sun spots1 #df4 ,seas1 ,lun>1 #id4 ,seasons on ! ,e>?1 #ed1 #gd4 ,sec*i1 ,a41 #bh1 #ce1 #db1 #ej1 #hd1 #hf1 #ajf4 ,second>y ,planets1 #h4 ,%akespe>e1 citations f1 #aeb4 ,smy?1 ,c4 ,p41 #ib4 ,sn[ on ,v5us1 #ff2 on ,m>s1 #ajd2 d\btful on ,saturn1 #abc4 ,sol/ices1 #gd4 ,sph]ical =m ( ! ,e>?1 #gj4 ,spr]1 #df1 #ej4 ,spots on ! ,sun1 #ba1 #aah2 on ,v5us1 #fa2 on ,jupit]1 #aag2 on ,saturn1 #abc4 ,/ew>t1 ,b41 #eb1 #ef4 ,/ruve1 ,o41 #acd1 #adb4 ,sun1 #ah1 #ahc4 ,sup]ior ,planets1 #h2 movem5ts (1 #ae4 ,surfaces ( ! ,sun & ,planets1 #ahc4 ,swift's ,comet1 #afh4 ,sy/ems ( ! ,univ]se1 #gb4 ,t4 ,tables ( ! ,major ,planets1 #ahc4 ,tails ( ,comets1 #aed4 ,temple's ,p]iodical ,comets1 #afg4 ,t]m9ator ( ! ,moon1 #ij4 ,?omson's ,seasons cit$1 #aec4 ,tides1 #ih4 ,total ,eclipses ( ! ,sun1 #eg4 ,transits ( inf]ior ,planets1 #ac1 #be1 #fe4 ,tr\velot1 #acc4 ,turtle's ,p]iodical ,comet1 #afg1 #afh4 ,twilight1 #hj4 ,tw9kl+1 #hc4 ,ty*o 7,lun> ,m\nta9s71 #id4 ,ty*o ,brahe1 #gc4 ,ty*onic ,sy/em1 #gc4 ,u4 ,umbra ( a ,sun-spot1 #bb4 ,uranus1 #ach2 ! influ5ce ( ,neptune on1 #adc4 ,v4 ,velocity ( ! planets1 #ahc4 ,v5us1 #fa2 phases (1 #ae2 its influ5ce on ,sun-spots1 #ea1 #eb1 #ec4 ,v]nal ,equ9ox1 #gd4 ,ve/a 7m9or planet71 #aab1 #aac4 ,virgil1 citation f1 #ej4 ,volume ( ! ,sun1 #bj2 ( ! ,planets1 #ahc4 ,w4 ,wea!r influ5ces ascrib$ to ! ,sun1 #dd2 to ! ,moon1 #ih4 8,will[ leaves0 on ! ,sun1 #ci1 #dj4 ,wilson's !ory ( ,sun-spots1 #cb4 ,w9necke's ,p]iodical ,comet1 #afg4 ,wolf1 ,r41 obs]v] ( ,sun-spots1 #de1 #dh4 ,wolf's ,p]iodical ,comet1 #afh4 ,y4 ,"y1 ,c4 ,a41 #aca4 ,z4 ,zodiac1 movem5t ( ,planets 91 #ae4 ,,! ,,end4 ,transcrib]'s ,notes --,"s palpable typographical errors 7 correct$4 --,copyright & publi%]'s in=mation 0 includ$ f ! pr9t$ copy3 ?is e,book is public doma9 9 ! c\ntry ( publication4