->S^.^ ) 374 ( ^?^- 



Ex allatis cxemplis fatii liqiict, crrorcm Qiia- 

 drantis propc Zcni;h parum dilfcrre ab errorc eiiisdcm 

 ad horizoatem: difcrcpantia paucoriim fccundornm partim 

 obfcruationibus partim tdbnlis ct rcduiflionibus adlcribl 

 poteft. Hinc fumto ex vtroquc medio prodit illc — 3*50''^ 

 qucm a vcro 5 fccundis vix abhidcrc vcrifiinilHmuni cft. 



Dctcrminatio latitndinis cx altitudiiiibus Solis 

 et fixarum mcridianis. 



Pofitioncm mcridiani detcrminabam ope circuH a- 

 zimuthalis, pedi Quadrantis adncxi , cuius diamctcr cft 

 X2j polhcum. Capicndo aUitudincs Sohs corrcfptmdcntcs 

 in ipfo tubi ccntro, notubam gradus ct minuta in circulo 

 mcmorato; atquc ex obfcruationibus matutinis ct pomeri- 

 dianis fumcbam mcdium, cui ob variationcm decHnationi* 

 Sohs hanc apphcui corrcdioncm. 



Dcnotantibus P clcuatione Poh 



D dcchnatione Solis boreah 



;;; corrcdionc meridici in fecundis, 



corrcdio quaefita =j!;^-^-^ = i 5 ''' cof D cofcc. (P - D) 

 quae in minuta prima commutata codcm modo ac corrc- 

 «flio mcndici apphcatur, in fignis ncmpc dcfccndcntibiis 

 additur, in afccndcntibus lubtrahitur. Pofito hoc modo 

 Quadrantc in mcridianum, dilfcrcntia intcr appulfum ccii- 

 tii foiis ad fihim micromctri vcrticalc, et mcridicm vc- 

 rum pcr altitudincs corrcfpundcntcs rcpcrtum, raro ad 6 

 vcl 8 fcrupula icmporis lccunda alhugcbat. 



Circa 



