rragnum tcmporis intcriialliim aHlgnari , ac tnlcm obfcr- 

 \aiionum fcricm pro lubitii vlterius continuari pofle. 



§■ I". Quoniam inuefligatio altiorum difTerentia» 

 lium binarum quantitatum p ti q fatis niolcftum calculum 

 pofhilat et mox ad enormem tcrminorum numerum cx- 

 crcfcit: hoc labore facilc lupcrfcdcre potciimus , fi modo 

 intcruallo tcmporis w aliquanto minorcm vaiorcm tiibua- 

 mi:s; tum autem ilLis operationcs pluries rcpctcre oportc- 

 bit. Ncquc vero ciiam ncceffc erit, in his detcrminationi- 

 bus fummum rigorcm obfcruare, quafi talis motus in coclo 

 rcuera exillcret ; fed quoninm noflrum inflitutum co tan- 

 tum dirigitur, ^t cx contemplationc fatis longae fcriei hu- 

 iusniodi obfcru.itionum cercum qiicndam ordincm ct lcgcm, 

 quafi diuinando cliciamus ; parum rcferct, vtrum loca as- 

 fignata fummo rigore fucrint computata, fiuc parumper a 

 Ycritatc difcrepaucrint. Qui crgo talcm laborem fufcipcrc 

 volucrir, haud cxiguum frudum in i\lhonoir.iam atiulilTc 

 erit ccnfcndus. 



Exempliim. 



f. 14.. Ponamus prin.o initio, cum Sol vcrfaretur 

 in A , corpus noflrum lunarc in ip(o plano cclipticac ad 

 diHantiam a Tcrra T I r o, cos ita normalitcr ad dircdic- 

 ncm TA fiiiflc proic^flum , vt cius motus angularis circa 

 Tcrram duplo rapidior fucrii quam motus Solis, atquc cx 

 liac dctcrminationc (lafus naturalis inucftigabimus motum, 

 quo h<>c corpus dcinccps cft progrcflurum. In lioc igitur 

 lcmporc primam cpocham conftituan us, pro qua proptcrca 

 liabcbinius fcqucntcs conditioncs: 



x*. 



