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Büt because in. Obsemtions madc by the Bare Eye, these tim« considerabiyDiffer srom rhose with a Teleseope j and because the Beginning os Eclipses, andthe End of Total Darkneß, are scarce ro. be observed exactly, even with Glaslesnone being able clearly to distinguisti between the True Shadow and Penumbra,unless he hath scen for some time before, the Line separating th«m, paß alongupon the Surface of the Moon ; ) and lastly, Because in finali Partial Eclipses,the Beginning and End, and in Total Ones of small continuance in the Shadow,the Beginning and End of Total Darknese are unfit for Nitie Observations, ,byreasoq of the flow Change of Appearances, which the Oblique Motion of theShadow th£n causeth. For thde Reasons I {hall propourtd a Mcthod peculiarlydesigned for the Accomplifliment of the Geographical End in observing LunarEclipses, free ( as far as is poflible) from all the mentioned Inconveniendes.i For, First, st {hall not be Practicable without a Teleseope. Secondly, TheObserver, {hall flways have Opportunity, before his PrincipalObservation, to notcthe Distinctlon between the True Shadow and the Penumbra. And, Thirdly,

It {hall bc applicable to those Seasbns of the Eclipse, when there is the ludden-est Alteration in the Appearances. To satisfic all which Intents,

Let there bc of the Eminentes! Spots, dispersed overall Qiiarters oftheMoon’sSurface, a select Numbcr generallly agreed-on, to be constantly made use of, tothis Purpose, in all Parts of the World. As for Example, thole, which M,

Hc'vetius callfth, M. Sinai, M. JEi.ua, M. Porpbyrites, M. Sercrtmt, Inß-Besbicus,hiß Creta, Palus Maotis, Palus Mar, catis, . Lacus Xigcr Maj er.

Let in-each Eclipse, not all, but ( for Instance ) three of thefc Spats, whichtheu lie nearest to the Ecliptick, be exactly observ’d,when they-are First touch’dby. the. True.Shadow, and again, when they are just compleatly Entred into it,anst ( if ypu please) also in the Decrease ot the Edipsei when theyare firfl: ful-ly cfear from the.True Shadow. for the accurate Dctefminations of which Mo-ments of time ( that being in this Busineß of main hnportance ) let there be ta-ken Altitudes of Remarkable Fixt Stars ; on this side of the. Line, of such as Isebetween the /Equator and Trc/iicseof Cancer ; but beyond the Line, of siteh a$ aresituate towards the Othcr Tropick; and in, all Plaetfy pf such as at the TimeofiObservation are abottt sour Hours distans stom the Meridian.

2- Eclipsis Lun,t, Diei 29. 03 . An. 1697 . Observata «st Poterodami per Te- By M. Ja. Casi-lescopiutn quatuor sere pedum Parisiensium Octidao Convexo,in cujus Foco erant sini * n *

Fila Quatuor, sese in Axe intersecantia ad Angulos Rectos Sx. Semirectos, ad f ' li>

Phales dimetiendas, Macularumque Lunarium situm determinandum# Hoc Te- Vid: mfraikseopmm impolitum erat Fulcro habenti Axem in-situ parallelo Axi Mundi.con- ^ LIV ' 2 ‘stitutum, ut postquam ad Lunam directum esset ad unius Phasi-Observationem, F.'g. 15.;..poflyt ad alias Phases observandas per Lunae Semitam ad. Occasum fcyolvi; - Itaautem primo dirigebatur ad Lunam, ut eo stnmotö permanente Lunae LimbusBoreasts luo Motu ad Occasum raderet unum ex his Filis,, quod ideo Parallelumdicimus, licet ob Motum Lunas in Declinationem Motui Lunae ad Occasum-multo celeriori commixtura non nihil ab iEquatpre declinaret dum Lunae Diseusin reliqua tria Fila successive incideret. Horum triqm Fiseufura intermedium An*gulos Rectos cum-Parallelo efficiens, Rectum Perpendiculare ÖC. Verticale appel?lamus. Reliqua duo. Obliqua, quorunv Primum dicimus in' quod' prius Luna in-cidit, Secundum Obliquum in quod--Luna incidit posterius. Initio Eclipsis,

quando