{"id":2357,"date":"2017-11-14T14:54:29","date_gmt":"2017-11-14T14:54:29","guid":{"rendered":"http:\/\/uni.hi.is\/einar\/?p=2357"},"modified":"2017-11-14T14:54:29","modified_gmt":"2017-11-14T14:54:29","slug":"solblettarannsoknir-christians-horrebow-i-sivalaturni-med-thatttoku-eyjolfs-jonssonar-og-rasmusar-lievog","status":"publish","type":"post","link":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/?p=2357","title":{"rendered":"S\u00f3lblettaranns\u00f3knir Christians Horrebow \u00ed S\u00edvalaturni me\u00f0 \u00fe\u00e1ttt\u00f6ku Eyj\u00f3lfs J\u00f3nssonar og Rasmusar Lievog"},"content":{"rendered":"

Fyrstu ritu\u00f0u heimildirnar<\/a> um s\u00f3lbletti eru k\u00ednverskar og fr\u00e1 \u00fev\u00ed \u00e1 \u00e1ttundu \u00f6ld f.Kr. \u00c1 Vesturl\u00f6ndum s\u00e1ust \u00feessi fyrirb\u00e6ri einstaka sinnum, allt fr\u00e1 d\u00f6gum Forn-Grikkja fram \u00e1 sautj\u00e1ndu \u00f6ld, \u00e1n \u00feess \u00fe\u00f3 a\u00f0 menn tengdu \u00feau endilega beint vi\u00f0 s\u00f3lina. Oftast var tali\u00f0, a\u00f0 um v\u00e6ri a\u00f0 r\u00e6\u00f0a \u00feverg\u00f6ngur f\u00f6ruhnatta, einkum Merk\u00far\u00edusar, og umfj\u00f6llun um s\u00f3lbletti var \u00fev\u00ed l\u00edtil sem engin.<\/p>\n

\u00dea\u00f0 var \u00fev\u00ed ekki fyrr en Gal\u00edle\u00f3<\/a> gaf \u00fat hi\u00f0 merka rit sitt um s\u00f3lbletti<\/a>, \u00e1ri\u00f0 1613, sem umr\u00e6\u00f0ur um s\u00f3lbletti t\u00f3ku flugi\u00f0. Um \u00fe\u00e1 \u00e1hrifamiklu b\u00f3k og vi\u00f0br\u00f6g\u00f0in vi\u00f0 henni m\u00e1 lesa h\u00e9r<\/a>.<\/p>\n

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Teikning Gal\u00edle\u00f3s af s\u00f3larkringlunni, 23. j\u00fan\u00ed 1613.<\/figcaption><\/figure>\n

S\u00f3lblettaathuganir \u00ed S\u00edvalaturni<\/em><\/span><\/p>\n

Danska stj\u00f6rnufr\u00e6\u00f0ingsins Christians Horrebow<\/a> er n\u00fa einkum minnst fyrir ranns\u00f3knir \u00e1 s\u00f3lblettum, enda mun hann hafa veri\u00f0 me\u00f0 fyrstu m\u00f6nnum til a\u00f0 fylgjast reglubundi\u00f0 me\u00f0 yfirbor\u00f0i s\u00f3larinnar.<\/p>\n

Fyrir hans daga var Rasmus Bartholin<\/a> eini stj\u00f6rnumeistarinn \u00ed S\u00edvalaturni<\/a>, sem vir\u00f0ist hafa haft svipa\u00f0an \u00e1huga, en \u00fe\u00e6r ranns\u00f3knir st\u00f3\u00f0u stutt, jafnvel ekki nema eitt e\u00f0a tv\u00f6 \u00e1r. B\u00e6\u00f0i Ole R\u00f8mer<\/a> og Peder N. Horrebow<\/a>, fa\u00f0ir Christians, m\u00e6ldu s\u00fdndar\u00feverm\u00e1l s\u00f3larinnar \u00e1 mismunandi \u00e1rst\u00edmum og notu\u00f0u ni\u00f0urst\u00f6\u00f0urnar til a\u00f0 \u00e1kvar\u00f0a hringvik jar\u00f0brautarinnar. Eftir \u00fev\u00ed sem best er vita\u00f0 voru \u00fea\u00f0 einu ranns\u00f3knir \u00feeirra \u00e1 s\u00f3larkringlunni.<\/p>\n

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Teikning danska arkitektsins Lauritz de Thurah af S\u00edvalaturni \u00e1ri\u00f0 1748. Athugunarst\u00f6\u00f0in er \u00e1 turn\u00feakinu. H\u00fan haf\u00f0i l\u00edti\u00f0 breyst, \u00feegar Eyj\u00f3lfur J\u00f3nsson og s\u00ed\u00f0ar Rasmus Lievog st\u00f6rfu\u00f0u \u00fear vi\u00f0 stjarnm\u00e6lingar.<\/figcaption><\/figure>\n

\u00de\u00f3tt Christian Horrebow hafi einnig gert svipa\u00f0ar m\u00e6lingar, beindist \u00e1hugi hans fyrst og fremst a\u00f0 s\u00f3lblettunum og heg\u00f0un \u00feeirra. Hann t\u00f3k a\u00f0 sko\u00f0a blettina og skr\u00e1 fj\u00f6lda \u00feeirra sk\u00f6mmu eftir a\u00f0 hann h\u00f3f st\u00f6rf hj\u00e1 f\u00f6\u00f0ur s\u00ednum og fylgdi \u00feeim ranns\u00f3knum eftir allt til dau\u00f0adags, n\u00e6r fj\u00f6rut\u00edu \u00e1rum s\u00ed\u00f0ar. \u00c1 \u00e1runum \u00ed kringum dv\u00f6l fyrsta \u00edslenska stj\u00f6rnufr\u00e6\u00f0ingsins, Eyj\u00f3lfs J\u00f3nssonar<\/a>,<\/span> \u00ed Kaupmannah\u00f6fn vir\u00f0ast f\u00e1ir hafa fylgst jafn vel me\u00f0 blettunum og stj\u00f6rnufr\u00e6\u00f0ingarnir \u00ed S\u00edvalaturni. Um \u00feessar athuganir m\u00e1 me\u00f0al annars lesa \u00ed n\u00fdlegri meistararitger\u00f0<\/a> eftir Carsten S. J\u00f6rgensen. Bestu heimildina um d\u00f6nsku ranns\u00f3knirnar er \u00fe\u00f3 a\u00f0 finna \u00ed merkri grein fr\u00e1 1770<\/a>\u00a0 eftir Christian Horrebow sj\u00e1lfan (sj\u00e1 bls. 469-536). \u00dear birtir hann ni\u00f0urst\u00f6\u00f0ur \u00far athugunum stj\u00f6rnufr\u00e6\u00f0inganna \u00ed S\u00edvalaturni \u00e1 s\u00f3lblettum \u00e1ri\u00f0 1769 og l\u00fdsir \u00feeim \u00ed sm\u00e1atri\u00f0um me\u00f0 t\u00f6flum og teikningum.<\/p>\n

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Teikningarnar s\u00fdna hluta af ni\u00f0urst\u00f6\u00f0um s\u00f3lblettaathugana \u00ed S\u00edvalaturni sumari\u00f0 1769. \u00dar myndavi\u00f0auka me\u00f0 grein Horrebows fr\u00e1 1770. B\u00f3kstafirnir \u00e1 teikningunum v\u00edsa til frekari uppl\u00fdsinga um blettina \u00ed grein hans.<\/figcaption><\/figure>\n

\u00cd greininni fjallar Horrebow auk \u00feess um s\u00f6gu s\u00f3lblettaranns\u00f3kna fram a\u00f0 \u00feeim t\u00edma, l\u00fdsir blettum af mismunandi st\u00e6r\u00f0 og r\u00e6\u00f0ir sta\u00f0setningu \u00feeirra og hreyfingu. Jafnframt segir hann fr\u00e1 \u00fev\u00ed, a\u00f0 fj\u00f6ldi blettanna breytist me\u00f0 t\u00edma og getur \u00feess s\u00e9rstaklega, a\u00f0 \u00feeir hafi veri\u00f0 \u00f3venju f\u00e1ir \u00e1 seinni hluta sautj\u00e1ndu aldar og \u00ed byrjun \u00feeirrar \u00e1tj\u00e1ndu, \u00e1 skei\u00f0i sem n\u00fa er venjulega kennt vi\u00f0 enska stj\u00f6rnufr\u00e6\u00f0inginn E. W. Maunder<\/a>. Fr\u00e1 \u00fev\u00ed hann h\u00f3f ranns\u00f3knir hafi hann hins vegar sjaldan s\u00e9\u00f0 s\u00f3lina \u00e1n bletta og fj\u00f6ldi \u00feeirra s\u00e9 \u00f3venju mikill um \u00feessa mundir (s\u00f3lsveiflan vir\u00f0ist einmitt hafa n\u00e1\u00f0 h\u00e1marki \u00e1ri\u00f0 1769). (Sj\u00e1 einnig Vi\u00f0b\u00f3t 1<\/em> \u00ed lok f\u00e6rslu.)<\/p>\n

M\u00e6lingar fyrir \u00f6nnur \u00e1r en 1769 birti Horrebow \u00ed Dansk Historisk Almanak,<\/em> sem Danska V\u00edsindaf\u00e9lagi\u00f0 gaf \u00fat (sj\u00e1 meistararitger\u00f0<\/a> J\u00f6rgensens).<\/p>\n

Samkv\u00e6mt grein Horrebows var \u00fea\u00f0 fyrst og fremst p\u00f3lst\u00e6\u00f0i R\u00f8mers (Machina aequatorea), sem nota\u00f0 var vi\u00f0 athuganir \u00e1 s\u00f3lblettum \u00ed S\u00edvalaturni (fr\u00e1 og me\u00f0 1767). P\u00f3lst\u00e6\u00f0i\u00f0 skemmdist illa \u00ed brunanum mikla 1728<\/a>, svo anna\u00f0hvort hefur \u00fea\u00f0 veri\u00f0 gert upp e\u00f0a endursm\u00ed\u00f0a\u00f0. \u00c1 \u00fea\u00f0 var venjulega settur 94 cm linsusj\u00f3nauki me\u00f0 \u00fer\u00e1\u00f0asigti og skr\u00fafum\u00e6li. Vita\u00f0 er, a\u00f0 sk\u00f6mmu \u00e1\u00f0ur en grein Horrebows var skrifu\u00f0, haf\u00f0i athugunarst\u00f6\u00f0in fengi\u00f0 n\u00fdjan t\u00edu feta langan og litvillulausan Dollond-linsusj\u00f3nauka me\u00f0 10 cm sj\u00f3ngleri. Hann mun hafa veri\u00f0 nota\u00f0ur vi\u00f0 blettaranns\u00f3knirnar \u00feegar a\u00f0st\u00e6\u00f0ur leyf\u00f0u.<\/p>\n

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P\u00f3lst\u00e6\u00f0i\u00f0 (Machina aequatorea) sem nota\u00f0 var vi\u00f0 s\u00f3lblettaranns\u00f3knirnar \u00ed S\u00edvalaturni. Myndin er \u00far b\u00f3k Peders N. Horrebow, Basis astronomiae<\/a>, fr\u00e1 1735. Sj\u00e1 einnig umfj\u00f6llun um m\u00e6lit\u00e6ki R\u00f8mers \u00ed grein Einars H. Gu\u00f0mundssonar<\/a> fr\u00e1 2008 (bls. 19-20).<\/figcaption><\/figure>\n

Eyj\u00f3lfur J\u00f3nsson og s\u00f3lblettirnir<\/em><\/span><\/p>\n

\u00c1 starfs\u00e1rum s\u00ednum \u00ed S\u00edvalaturni t\u00f3k Eyj\u00f3lfur J\u00f3nsson<\/span> virkan \u00fe\u00e1tt \u00ed ranns\u00f3knum Horrebows \u00e1 s\u00f3lblettum og \u00ed stjarnm\u00e6lingab\u00f3kum turnsins er a\u00f0 finna margar f\u00e6rslur fr\u00e1 honum. N\u00e6stu fj\u00f3rar myndir s\u00fdna hvernig unni\u00f0 var me\u00f0 ni\u00f0urst\u00f6\u00f0ur m\u00e6linganna.<\/p>\n

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B\u00e1\u00f0ar myndirnar eru \u00far stjarnm\u00e6lingab\u00f3k athugunarst\u00f6\u00f0varinnar \u00ed S\u00edvalaturni. S\u00fa efri s\u00fdnir fyrri \u00e1kv\u00f6r\u00f0un Eyj\u00f3lfs \u00e1 stj\u00f6rnuhnitum s\u00f3lbletta, 7. febr\u00faar 1768, \u00e1samt teikningu af st\u00f6\u00f0u \u00feeirra \u00e1 s\u00f3larkringlunni. \u00cd rau\u00f0u k\u00f6ssunum eru hnitin, t\u00edmahorni\u00f0 til vinstri og stj\u00f6rnubreiddin til h\u00e6gri. T\u00edmahorni\u00f0 er gefi\u00f0 upp \u00ed stj\u00f6rnut\u00edmaeiningum, en stj\u00f6rnubreiddin er m\u00e6ld \u00ed sn\u00faningum skr\u00fafum\u00e6lis mi\u00f0a\u00f0 vi\u00f0 ne\u00f0sta punkt s\u00f3larkringlunnar. Ne\u00f0ri myndin s\u00fdnir ni\u00f0urst\u00f6\u00f0ur \u00far seinni m\u00e6lingum Eyj\u00f3lfs sama dag. \u00de\u00e6r voru taldar n\u00e1kv\u00e6mari og \u00fev\u00ed birtar \u00ed Dansk Historisk Almanak<\/em> \u00e1ri\u00f0 1770. \u00dar meistararitger\u00f0<\/a> J\u00f6rgensen (bls. 66).<\/figcaption><\/figure>\n

 <\/p>\n

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Tafla og myndir \u00far grein Christans Horrebow \u00ed\u00a0Dansk Historisk Almanak<\/em> \u00e1ri\u00f0 1770. Taflan s\u00fdnir ni\u00f0urst\u00f6\u00f0urnar \u00far seinni m\u00e6lingum Eyj\u00f3lfs, 7. febr\u00faar 1768. Myndirnar s\u00fdna hins vegar ni\u00f0urst\u00f6\u00f0ur margra athugana fr\u00e1 mismunandi t\u00edmum. \u00cd efra horninu h\u00e6gra megin (Fig. 8) er teikning Eyj\u00f3lfs (\u00far fyrri f\u00e6rslunni) af s\u00f3larkringlunni 7. febr\u00faar 1768. \u00dar meistararitger\u00f0<\/a> J\u00f6rgensen (bls. 67).<\/figcaption><\/figure>\n

Vi\u00f0 ranns\u00f3knir \u00e1 s\u00f3linni, \u00f3h\u00e1\u00f0 \u00fev\u00ed hvort fylgst var me\u00f0 s\u00f3lblettum, s\u00f3lmyrkvum e\u00f0a \u00f6\u00f0rum fyrirb\u00e6rum tengdum \u00feessum bjarta himinhnetti, var eins og n\u00fa h\u00e6gt a\u00f0 nota tv\u00e6r mismunandi a\u00f0fer\u00f0ir til a\u00f0 vernda augun. Anna\u00f0hvort l\u00e9tu menn s\u00f3larlj\u00f3si\u00f0 falla \u00e1 skerm \u00fear sem h\u00e6gt var a\u00f0 sko\u00f0a mynd af s\u00f3linni, e\u00f0a \u00feeir settu s\u00f3lars\u00edu \u00e1 sj\u00f3naukann og horf\u00f0u beint \u00ed s\u00f3lina \u00ed gegnum s\u00eduna. \u00cd S\u00edvalaturni, eins og \u00ed \u00f6\u00f0rum stj\u00f6rnuathugunarst\u00f6\u00f0vum, voru s\u00edurnar anna\u00f0hvort ger\u00f0ar \u00far litgleri e\u00f0a reykgleri.<\/p>\n

\u00cd \u00feessu sambandi eru athyglisver\u00f0 umm\u00e6lin, sem Uno von Troil<\/a> hefur um Eyj\u00f3lf J\u00f3nsson \u00ed tveimur br\u00e9fum \u00e1ri\u00f0 1773, en hann haf\u00f0i hitt stj\u00f6rnumeistarann \u00e1 Arnarh\u00f3li \u00e1ri\u00f0 \u00e1\u00f0ur. Br\u00e9fin birti hann \u00ed hinu \u00feekkta riti s\u00ednu, Bref r\u00f6rande en resa til Island<\/a>, fr\u00e1 1777. \u00cd \u00fev\u00ed fyrra segir (bls. 40):<\/p>\n

[Jonson]<\/em> nyttjade med f\u00f6rdel, uti en af sig paafunnit telescop, Islands saa kallade svarta agat, i stellet for r\u00f6kt glas.<\/p><\/blockquote>\n

Og \u00ed \u00fev\u00ed s\u00ed\u00f0ara (bls. 247):<\/p>\n

Af detta svarta glas [\u00fe.e. svarta agat]<\/em>, har Herr Observat. Ej. Jonss, s\u00e5 vel \u00ed Ki\u00f6benhavn som Island, nyttjad til solaire tuber, i st\u00e4llet et annars r\u00f6ka glasen, och funnit detta mycket b\u00e4ttre.<\/p><\/blockquote>\n

Svarta agat<\/em> \u00e1 s\u00e6nsku er \u00fea\u00f0 sem vi\u00f0 \u00cdslendingar k\u00f6llum hrafntinnu<\/em> (\u00e1 d\u00f6nsku er tala\u00f0 um sort agat<\/em> og \u00e1 ensku obsidian)<\/em>. Samkv\u00e6mt \u00feessu hefur Eyj\u00f3lfur \u00fatb\u00fai\u00f0 s\u00f3lars\u00edur \u00far hrafntinnu\u00feynnum og nota\u00f0 vi\u00f0 s\u00f3larranns\u00f3knirnar \u00ed S\u00edvalaturni me\u00f0 g\u00f3\u00f0um \u00e1rangri. Jafnframt m\u00e1 r\u00e1\u00f0a af or\u00f0um von Troils, a\u00f0 Eyj\u00f3lfur hefur haldi\u00f0 \u00e1fram a\u00f0 fylgjast me\u00f0 s\u00f3laryfirbor\u00f0inu eftir a\u00f0 hann kom aftur til \u00cdslands. Er \u00feetta eina heimildin, sem \u00e9g hef fundi\u00f0 um \u00fe\u00e6r athuganir.<\/p>\n

H\u00e9r m\u00e1 einnig geta \u00feess, a\u00f0 \u00ed kennslub\u00f3k sinni \u00ed stj\u00f6rnufr\u00e6\u00f0i<\/a> <\/span><\/span>fr\u00e1 1796 tekur Thomas Bugge<\/a> \u00fea\u00f0 s\u00e9rstaklega fram, a\u00f0 hrafntinnu\u00feynnur s\u00e9u me\u00f0 afbrig\u00f0um g\u00f3\u00f0ar s\u00f3lars\u00edur (bls. 173)<\/span><\/span>. Hann minnist \u00fe\u00f3 ekki \u00e1 Eyj\u00f3lf \u00ed \u00fev\u00ed sambandi. \u00deeir Bugge og Eyj\u00f3lfur vir\u00f0ast ekki hafa haft mikil samskipti me\u00f0an s\u00e1 s\u00ed\u00f0arnefndi var \u00ed H\u00f6fn, enda var Bugge \u00fe\u00e1 \u00f6nnum kafinn vi\u00f0 landm\u00e6lingar og kortager\u00f0. Hvernig sem \u00e1 \u00fev\u00ed stendur vir\u00f0ist hrafntinna hvergi hafa veri\u00f0 notu\u00f0 vi\u00f0 s\u00f3larathuganir nema \u00ed S\u00edvalaturni og \u00e1 Arnarh\u00f3li, alla vega hef \u00e9g ekki enn fundi\u00f0 neinar heimildir um sl\u00edkt.<\/p>\n

Kenningar um e\u00f0li s\u00f3lbletta
\n<\/em><\/span><\/p>\n

\u00cd fyrrnefndri grein fr\u00e1 1770 fjallar Christian Horrebow um \u00fdmsar eldri hugmyndir um ger\u00f0 og e\u00f0li s\u00f3larinnar (bls. 473-74). Hann telur a\u00f0 kenning, sem hann eignar franska st\u00e6r\u00f0fr\u00e6\u00f0ingnum og n\u00e1tt\u00faruspekingnum Philippe de La Hire<\/a>, s\u00e9 \u00ed bestu samr\u00e6mi vi\u00f0 s\u00ednar eigin athuganir. Samkv\u00e6mt t\u00falkun Horrebows \u00e1 kenningunni er s\u00f3lin risast\u00f3r k\u00fala me\u00f0 miklum \u00f3j\u00f6fnum \u00e1 yfirbor\u00f0inu, st\u00f3rum sem sm\u00e1um, d\u00f6lum sem fj\u00f6llum. K\u00falan er umvafin flj\u00f3tandi eldefni (\u00fea\u00f0 er lj\u00f3shvolfi), sem h\u00e6kkar og l\u00e6kkar \u00e1 v\u00edxl, l\u00edkt og h\u00f6fin \u00e1 j\u00f6r\u00f0inni. Blettirnir eru mish\u00e1ir fjallstindar, sem koma \u00ed lj\u00f3s vi\u00f0 l\u00e6kkun eldhj\u00fapsins, en hverfa svo aftur, \u00feegar hj\u00fapurinn h\u00e6kkar. \u00deeir eru flestir vi\u00f0 mi\u00f0baug, \u00fev\u00ed \u00fear eru fj\u00f6llin h\u00e6st eins og \u00e1 j\u00f6r\u00f0inni. L\u00fdsing Horrebows er sennilega fengin \u00far kennslub\u00f3k \u00ed stj\u00f6rnufr\u00e6\u00f0i<\/a> eftir J\u00e9r\u00f4me Lalande<\/a> (2. bindi 1764, bls. 1209-10). Ef haft er \u00ed huga, hversu skammt ranns\u00f3knir \u00e1 s\u00f3linni voru \u00e1 veg komnar \u00e1 d\u00f6gum Horrebows, var \u00feetta alls ekki svo sl\u00e6m kenning. Thomas Bugge tekur til d\u00e6mis undir hana \u00ed stj\u00f6rnufr\u00e6\u00f0ib\u00f3k sinni<\/a> fr\u00e1 1796 (bls. 147-48).<\/p>\n

\u00deegar skoski stj\u00f6rnufr\u00e6\u00f0ingurinn Alexander Wilson<\/a> beindi sj\u00f3nauka a\u00f0 s\u00f3linni \u00e1ri\u00f0 1769, s\u00e1 hann hins vegar engin fj\u00f6ll \u00ed blettunum, heldur virtust \u00feeir vera einskonar d\u00e6ldir \u00ed eldhvolfinu. Wilson birti ni\u00f0urst\u00f6\u00f0ur s\u00ednar 1774 og setti jafnframt fram \u00fe\u00e1 tilg\u00e1tu, a\u00f0 s\u00f3lblettirnir v\u00e6ru g\u00f6t \u00ed lj\u00f3shafinu og \u00ed gegnum \u00feau s\u00e6ist \u00ed d\u00f6kkt yfirbor\u00f0 hins eiginlega s\u00f3laryfirbor\u00f0s. \u00cd \u00feessu sambandi m\u00e1 geta \u00feess, a\u00f0 hausti\u00f0 1770 efndi danska V\u00edsindaf\u00e9lagi\u00f0 til ver\u00f0launasamkeppni um svar vi\u00f0 spurningunni Hva\u00f0 eru s\u00f3lblettir<\/em>? Verkefni\u00f0 var \u00e1n efa komi\u00f0 fr\u00e1 Christian Horrebow. Alexander Wilson voru veitt ver\u00f0launin \u00ed \u00e1rsbyrjun 1772, \u00fe\u00f3tt tali\u00f0 v\u00e6ri a\u00f0 hann hef\u00f0i ekki f\u00e6rt n\u00e6gjanlegar sannanir fyrir kenningu sinni.<\/p>\n

Hinn \u00feekkti stj\u00f6rnufr\u00e6\u00f0ingur William Herschel<\/a> a\u00f0hylltist einnig \u00feessa kenningu. A\u00f0 auki taldi hann l\u00edklegt, a\u00f0 s\u00f3laryfirbor\u00f0i\u00f0 v\u00e6ri ekki mj\u00f6g fr\u00e1brug\u00f0i\u00f0 yfirbor\u00f0i jar\u00f0arinnar og \u00fear v\u00e6ru sennilega lifandi verur. R\u00e9tt er a\u00f0 minna \u00e1, a\u00f0 hugmyndir um kaldan s\u00f3larhn\u00f6tt hj\u00fapa\u00f0an heitu eldhvolfi voru r\u00edkjandi me\u00f0al stj\u00f6rnufr\u00e6\u00f0inga og e\u00f0lisfr\u00e6\u00f0inga allt fram \u00e1 sj\u00f6unda \u00e1ratug n\u00edtj\u00e1ndu aldar, \u00feegar s\u00fdnt var fram \u00e1 \u00fea\u00f0 me\u00f0 litr\u00f3fsm\u00e6lingum, a\u00f0 \u00fe\u00e6r st\u00f3\u00f0ust ekki.<\/p>\n

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Mynd \u00far grein eftir William Herschel fr\u00e1 1801. H\u00fan l\u00fdsir kenningu hans um e\u00f0li s\u00f3lbletta: S\u00f3lin er d\u00f6kkur og kaldur risahn\u00f6ttur, bygg\u00f0ur lifandi verum. Umhverfis hann er eldhvolf me\u00f0 g\u00f6tum og geta jar\u00f0arb\u00faar og a\u00f0rir s\u00e9\u00f0 d\u00f6kkt s\u00f3laryfirbor\u00f0i\u00f0 \u00ed gegnum \u00feau. \u00deetta sk\u00fdrir s\u00f3lblettina. \u00c1 ne\u00f0ra bor\u00f0i eldhvolfsins \u00fearf a\u00f0 vera einhvers konar skj\u00f6ldur, t.d. d\u00f6kkt millihvolf, eitt e\u00f0a fleiri, til \u00feess a\u00f0 s\u00f3larb\u00faar stikni ekki. Herschel setti \u00feessa kenningu fyrst fram \u00e1ri\u00f0 1795 og studdist \u00fear vi\u00f0 hugmynd Alexanders Wilson fr\u00e1 1774. Hennar var lengi geti\u00f0 \u00ed al\u00fe\u00fd\u00f0uritum um stj\u00f6rnufr\u00e6\u00f0i, t.d. Vorum s\u00f3lheimum<\/a> eftir Magn\u00fas Stephensen<\/a> (bls. 55) og\u00a0 Stj\u00f6rnufr\u00e6\u00f0i<\/a> Ursins<\/a> (bls. 10-11).<\/figcaption><\/figure>\n

Fj\u00f6ldi s\u00f3lbletta<\/em><\/span><\/p>\n

\u00cd merkri grein fr\u00e1 1843 birti Heinrich Schwabe<\/a>, \u00fe\u00fdskur \u00e1hugama\u00f0ur um stj\u00f6rnufr\u00e6\u00f0i, tilg\u00e1tu \u00feess efnis, a\u00f0 fj\u00f6ldi s\u00f3lbletta v\u00e6ri sveiflukenndur me\u00f0 um \u00fea\u00f0 bil t\u00edu \u00e1ra lotu. Ni\u00f0urst\u00f6\u00f0una bygg\u00f0i hann \u00e1 n\u00e6r tveggja \u00e1ratuga ranns\u00f3knum \u00e1 s\u00f3laryfirbor\u00f0inu. Uppg\u00f6tvunin vakti athygli svissneska stj\u00f6rnufr\u00e6\u00f0ingsins Rudolfs Wolf<\/a>, sem f\u00f3r flj\u00f3tlega a\u00f0 rannsaka s\u00f3lbletti sj\u00e1lfur. Jafnframt h\u00f3f hann a\u00f0 safna g\u00f6gnum um eldri m\u00e6lingar \u00e1 s\u00f3lblettum, allt aftur til \u00e1rsins 1610. \u00c1ri\u00f0 1852 haf\u00f0i hann komist yfir n\u00e6gjanlegt gagnamagn til a\u00f0 sta\u00f0afesta ni\u00f0urst\u00f6\u00f0ur Schwabes um s\u00f3lsveifluna og finna lotu hennar, sem reyndist vera 11 \u00e1r a\u00f0 me\u00f0altali. \u00c1 sama t\u00edma t\u00f3kst Wolf einnig a\u00f0 s\u00fdna fram \u00e1 sterka fylgni milli fj\u00f6lda s\u00f3lbletta og breytinga \u00e1 segulsvi\u00f0i jar\u00f0ar. \u00ddmsir a\u00f0rir komust a\u00f0 s\u00f6mu ni\u00f0urst\u00f6\u00f0u um svipa\u00f0 leyti.<\/p>\n

\u00dev\u00ed er \u00feetta nefnt h\u00e9r, a\u00f0 menn hafa l\u00f6ngum undrast, hvers vegna Christian Horrebow uppg\u00f6tva\u00f0i ekki s\u00f3lsveifluna l\u00f6ngu \u00e1 undan Schwabe. Sk\u00f6mmu \u00e1\u00f0ur en hann d\u00f3, \u00e1ri\u00f0 1776, haf\u00f0i Horrebow safna\u00f0 n\u00e6gum g\u00f6gnum til a\u00f0 sj\u00e1 sveifluna. \u00deetta m\u00e1 til d\u00e6mis sj\u00e1 \u00e1 myndinni h\u00e9r fyrir ne\u00f0an yfir fj\u00f6lda s\u00f3lbletta \u00e1 \u00e1runum 1761 til 1777.<\/p>\n

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Myndin s\u00fdnir me\u00f0alfj\u00f6lda s\u00f3lbletta samkv\u00e6mt m\u00e6lingum Christians Horrebow og samstarfsmanna hans \u00ed S\u00edvalaturni \u00e1 \u00e1runum 1761-1777. Eyj\u00f3lfur J\u00f3nsson t\u00f3k \u00fe\u00e1tt \u00ed m\u00e6lingunum \u00e1 \u00e1runum 1767 til 1770. Rasmus Lievog s\u00e1 um m\u00e6lingarnar 1776 til 1777 og Thomas Bugge um \u00fe\u00e6r allra s\u00ed\u00f0ustu, seinni hluta \u00e1rsins 1777. L\u00ednuriti\u00f0 er teki\u00f0 \u00far \u00far b\u00f3k Hoyts og Schattens <\/a>fr\u00e1 1997 (bls. 31), sem jafnframt gefur stutt og hnitmi\u00f0a\u00f0 yfirlit yfir s\u00f6gu s\u00f3larranns\u00f3kna. Sj\u00e1 einnig grein \u00feeirra<\/a> fr\u00e1 1995 um m\u00e6lingar Horrebows.<\/figcaption><\/figure>\n

Einhverra hluta vegna birti Horrebow ekkert um athuganir s\u00ednar \u00e1 \u00f6\u00f0rum tungum\u00e1lum en d\u00f6nsku og \u00fea\u00f0 kom \u00fev\u00ed \u00ed hlut danska stj\u00f6rnufr\u00e6\u00f0ingsins og st\u00e6r\u00f0fr\u00e6\u00f0ingsins Thorvalds N. Thiele<\/a> a\u00f0 birta m\u00e6lingarnar \u00e1 al\u00fej\u00f3\u00f0avettvangi, nokku\u00f0 sem hann ger\u00f0i a\u00f0 \u00e1eggjan Rudolfs Wolfs \u00e1ri\u00f0 1859. \u00dea\u00f0 var \u00fev\u00ed ekki fyrr en r\u00famum \u00e1ttat\u00edu \u00e1rum eftir l\u00e1t Horrebows, sem al\u00fej\u00f3\u00f0asamf\u00e9lag stj\u00f6rnufr\u00e6\u00f0inga f\u00e9kk fyrst uppl\u00fdsingar um hinar merku s\u00f3lblettaathuganir \u00ed S\u00edvalaturni.<\/p>\n

\u00de\u00f3tt l\u00edti\u00f0 hafi heyrst \u00ed Christian Horrebow erlendis, m\u00e1 sj\u00e1 \u00fea\u00f0 \u00e1 hinum d\u00f6nsku greinum hans, a\u00f0 hann var mj\u00f6g n\u00e1l\u00e6gt \u00fev\u00ed a\u00f0 uppg\u00f6tva s\u00f3lsveifluna. Til d\u00e6mis getur hann \u00feess \u00ed Dansk Historisk Almanak<\/em> \u00e1ri\u00f0 1775, a\u00f0 svo vir\u00f0ist sem fj\u00f6ldi og st\u00e6r\u00f0 s\u00f3lbletta endurtaki sig eftir \u00e1kve\u00f0inn \u00e1rafj\u00f6lda, \u00fe\u00f3tt enn s\u00e9 ekkert h\u00e6gt a\u00f0 fullyr\u00f0a um \u00fea\u00f0. \u00c1ri\u00f0 eftir segir hann svo \u00ed sama almanaki:<\/p>\n

Jafnvel \u00fe\u00f3tt athuganir s\u00fdni, a\u00f0 breytingar \u00e1 s\u00f3lblettum s\u00e9u algengar, \u00fe\u00e1 er ekki h\u00e6gt a\u00f0 finna neina fasta reglu um \u00fe\u00e6r, e\u00f0a hversu lengi breytingarnar vara. \u00c1st\u00e6\u00f0an er fyrst og fremst s\u00fa, a\u00f0 fram a\u00f0 \u00feessu hafa stj\u00f6rnufr\u00e6\u00f0ingar ekki fylgst mj\u00f6g n\u00e1i\u00f0 me\u00f0 s\u00f3lblettum. \u00dea\u00f0 er \u00e1n efa vegna \u00feess, a\u00f0 \u00feeir hafa tali\u00f0 a\u00f0 \u00fatkoman yr\u00f0i ekki s\u00e9rlega \u00e1hugaver\u00f0 fyrir stj\u00f6rnufr\u00e6\u00f0i og e\u00f0lisfr\u00e6\u00f0i. Vonandi tekst \u00fe\u00f3 me\u00f0 t\u00ed\u00f0ari m\u00e6lingum a\u00f0 finna sveiflut\u00edma breytinganna, eins og \u00feegar hefur tekist a\u00f0 finna reglu \u00ed hreyfingu hinna himinhnattanna. \u00de\u00e1 fyrst ver\u00f0ur h\u00e6gt a\u00f0 rannsaka hva\u00f0a \u00e1hrif s\u00f3lblettir hafa \u00e1 hnettina, sem s\u00f3lin l\u00fdsir upp og stj\u00f3rnar.<\/p><\/blockquote>\n

A\u00f0 lokum er h\u00e9r n\u00fdleg mynd af t\u00ed\u00f0ni s\u00f3lbletta fr\u00e1 1600 til 2009:<\/p>\n

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T\u00ed\u00f0ni s\u00f3lbletta fr\u00e1 1610 til 2009. Eftir 1749 er um m\u00e1na\u00f0arleg me\u00f0alt\u00f6l a\u00f0 r\u00e6\u00f0a. \u00dearna er me\u00f0al annars stu\u00f0st vi\u00f0 m\u00e6lingar Christians Horrebows og a\u00f0sto\u00f0armanna hans, \u00fear \u00e1 me\u00f0al Eyj\u00f3lfs J\u00f3nssonar, fr\u00e1 \u00e1runum 1761 og 1764-76. Einnig er stu\u00f0st vi\u00f0 m\u00e6lingar Rasmusar Lievog 1776-77 og Thomasar Bugge 1777. Sj\u00e1 n\u00e1nar h\u00e9r<\/a>.<\/figcaption><\/figure>\n

\u00d6rl\u00edti\u00f0 um Rasmus Lievog og Thomas Bugge<\/em><\/span><\/p>\n

Sk\u00f6mmu \u00e1\u00f0ur en Horrebow d\u00f3 h\u00f3f Rasmus Lievog<\/a> st\u00f6rf sem a\u00f0sto\u00f0arstj\u00f6rnumeistari \u00ed S\u00edvalaturni. Hann hefur greinilega hloti\u00f0 \u00fej\u00e1lfun \u00ed sko\u00f0un s\u00f3lbletta hj\u00e1 Horrebow, \u00fev\u00ed \u00feegar Thomas Bugge<\/a> t\u00f3k vi\u00f0 sem yfirstj\u00f6rnumeistari, \u00e1ri\u00f0 1777, l\u00e9t hann Lievog halda \u00e1fram s\u00f3lblettaathugunum um t\u00edma. Ni\u00f0urst\u00f6\u00f0ur \u00feeirra m\u00e6linga eru nota\u00f0ar \u00ed l\u00ednuritunum h\u00e9r fyrir ofan.<\/p>\n

Bugge var mun einbeittari og reglufastari v\u00edsindama\u00f0ur en Horrebow, h\u00e9lt g\u00f3\u00f0u sambandi vi\u00f0 erlenda stj\u00f6rnufr\u00e6\u00f0inga og birti margar m\u00e6lini\u00f0urst\u00f6\u00f0ur \u00ed erlendum t\u00edmaritum og b\u00f3kum. Hann a\u00f0hylltist framsetningu Newtons \u00e1 e\u00f0lisfr\u00e6\u00f0inni og haf\u00f0i or\u00f0i\u00f0 fyrir umtalsver\u00f0um \u00e1hrifum fr\u00e1 ensku uppl\u00fdsingunni.<\/p>\n

\u00de\u00f3tt Bugge hef\u00f0i pers\u00f3nulega mikinn \u00e1huga \u00e1 s\u00f3linni, t\u00f3k hann snemma \u00fe\u00e1 \u00e1kv\u00f6r\u00f0un a\u00f0 h\u00e6tta s\u00f3larathugunum a\u00f0 mestu og fylgja \u00ed sta\u00f0inn r\u00edkjandi straumum \u00ed stj\u00f6rnufr\u00e6\u00f0i.\u00a0Hann mun hafa veri\u00f0 me\u00f0 fyrstu m\u00f6nnum til a\u00f0 sj\u00e1 korn\u00f3tta \u00e1fer\u00f0 s\u00f3laryfirbor\u00f0sins, en hirti ekki um a\u00f0 birta ni\u00f0urst\u00f6\u00f0urnar \u00e1 al\u00fej\u00f3\u00f0avettvangi, heldur a\u00f0eins \u00ed kennslub\u00f3k sinni \u00e1ri\u00f0 1796 (bls. 144).<\/p>\n

\u00deannig einbeitti hann s\u00e9r a\u00f0 ranns\u00f3knum \u00e1 fyrirb\u00e6rum, sem \u00fe\u00f3ttu mikilv\u00e6gari en s\u00f3lin \u00e1 \u00feeim t\u00edma. \u00dea\u00f0 kann einnig a\u00f0 hafa \u00e1tt nokkurn \u00fe\u00e1tt \u00ed \u00e1kv\u00f6r\u00f0un hans, a\u00f0 hann mun hafa vanmeti\u00f0 h\u00e6fileika Christians Horrebow sem stj\u00f6rnufr\u00e6\u00f0ings. Ef Bugge hef\u00f0i hins vegar haldi\u00f0 \u00e1fram langt\u00edma ranns\u00f3knum fyrirrennara s\u00edns, samhli\u00f0a \u00f6\u00f0rum verkefnum, m\u00e1 telja n\u00e6r fullv\u00edst, a\u00f0 hann v\u00e6ri n\u00fa einkum \u00feekktur fyrir a\u00f0 uppg\u00f6tva s\u00f3lsveifluna. Segja m\u00e1, a\u00f0 \u00e1kv\u00f6r\u00f0un hans um ranns\u00f3knar\u00e1herslur s\u00e9 sl\u00e1andi d\u00e6mi um glata\u00f0 t\u00e6kif\u00e6ri \u00ed raunv\u00edsindum.<\/p>\n

Hinn kraftmikli Bugge vann skyldust\u00f6rf s\u00edn alla t\u00ed\u00f0 af mikilli samviskusemi og \u00ed s\u00f6nnum gu\u00f0s\u00f3tta. Hann var vins\u00e6ll me\u00f0al nemenda, en \u00fe\u00f3tti frekar einstrengislegur \u00ed stj\u00f3rnunarst\u00f6rfum. Hann lag\u00f0ist til d\u00e6mis gegn \u00fev\u00ed, a\u00f0 H. C. \u00d8rsted<\/a> og H. C. Schumacher<\/a> fengju \u00e1 s\u00ednum t\u00edma st\u00f6\u00f0ur vi\u00f0 Hafnarh\u00e1sk\u00f3la. Schumacher var\u00f0 s\u00ed\u00f0ar eftirma\u00f0ur Bugges og \u00d8rsted helsti raunv\u00edsindafork\u00f3lfur sk\u00f3lans. \u00deeir b\u00e1ru Bugge illa s\u00f6guna a\u00f0 honum l\u00e1tnum og komu \u00feannig \u00ed veg fyrir a\u00f0 hans yr\u00f0i minnst a\u00f0 ver\u00f0leikum fyrr en l\u00f6ngu s\u00ed\u00f0ar.<\/p>\n

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Vi\u00f0b\u00f3t 1<\/strong> (26. j\u00fan\u00ed 2019): N\u00fdlega birtust tv\u00e6r fr\u00f3\u00f0legar greinar um s\u00f3lblettaathuganir Horrebows \u00ed t\u00edmaritinu Solar Physics<\/em>: <\/span><\/p>\n