APPENDIXi Hanc itaque regulam pone fuper centrum rotula?, & fac vnum fo- ramen rotundum,id quod mittatur clauus cum foramine rotundus, qui ambo conftringar, ita vt index hac atque illac volui poffit. Vt patet in figura prsefenti. … f Vfns huiHS inftrumenti. N ftellifera no&is claritate fubleua rotulam cum manu- brio verfus feptentrionein,& moue rotulam huc & illuc, donec radius vifuahs ab oculo tuo per ccntrum inftru- menti ad ftellam poiarem tranfeat: Gmiliter extra rotu- lam idem radius ad extrcmas duas ftellas maioris…
Cosmography · Geography
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