415 METUODJ'S OBSERrJXDI 



fcd comn:! plr.ifcos tcmpore illo e loco fiio , qiiem iu 

 coiitaclii limbonim ciim cipillis immobiiibns tencb;\nt , mo- 

 tii pnmi mobilis hu;i 'cxeiiiit , ct :id c:ipiiliim , qiii ad ea 

 dirigitiii- , propiiis iiccediint , \el ;ib etxiem longiiis rccc- 

 diiiit •, :idco vt diiV.intia corum a iimbo proximo pcr ob- 

 rcrii.itionem hanc liimpta neced-uio maior , vcl minor vc- 

 ra , (cii ea , qu:ic in contacflii limboriim ciim capillis fuit , 

 c(ro debc:U. Nequc fola haec obleniatio crrori obnoxii 

 ell , fcd cundem in pri<«cm ctiam obleiiiationcm dcriuat , 

 augctotie. Propcrarc cnim dcbct oblcruator cum priori 

 oblenijtionc , licct ea id minimc patiatur , 11 accurata cllc 

 debeat , ne h.uic intermittat , vel non cxadc faciat , ct 

 dum aninnim ad vtramquc codem momento dillcndit , 

 neutram dcbito rigore tacict. Acccdit quod pcr micromc- 

 tron li(K nnn omni temporc obferuatioiicm huiusmodi in- 

 ftirucrc licc.u , fed illo tantum , quo phafis cclipfcos , feii 

 dilbmtia limborum cclipfuuis et oblaiiantis dill.iiuiac duo- 

 rum capillorum immobilium quorumcunqiic acqualis cft. 

 Fieri ergo potell , vt cxercitatilfimus oblcru:itor micn)mc- 

 tro huius generis exquilitilhmo inlhuL^us , cchpfiquc aj^pa- 

 renti obleruandac diligtntilfimc iiucntus ob iiicommodita- 

 tcs oblcruaudi liipra dclcriptas nullam pn)rfus harum ob- 

 fcnruionum inlhtucrc polht ^ praclertim autem fi dunuuc 

 cclipfi nubcs vci rarillimc ctiam intcrueniant aliquod(iuc 

 C quatuor illis puncflis ad ob!cruationcm hanc rcquifitis mo- 

 mcnto oblcruationi dcbito tcgant. Numcms cnim obfcr- 

 vationum huiu-moJi iii micn^mctro hoc , mcthodo eius iti 

 fcrciuc , exigmis taiitum poliibili»^ tll. Cum itaque obfcr- 

 vati') phafuim ecliplcos chordanimquc dcfcdiuanim codcm 

 tcmporis momcnto mnituenda tam nia^iiis diilicultatibiis 



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