( 3 5 ? >

8. The Comet, Atm. 1 6jz. had (on ehe first of April , St. A’.) pass'd 45L > 5 ,^ -n

Iseyond lhe most Northern Star of the Head of Taurus, and was distant i°. 43 '. Rossini/sirom the Star that was nearest to that towards the South. M. Castni having n. 82. f. 424S.consider’d these two Stars,, observ'd, That the Second is not leis bright thanthe First, and yet that Baycrus hath not marked it; And that at first Sight, itseems that Tycho hath lest it out in his Catalogue. For he puts fbur Stars inthe Place he calls in Quadrilatcro Cervicis, and he speaks not of this which isthe fifth, and maketh with the other four an Irregulär Pentagone. ThisOmission of Baycrus, and the Denomination which Tycbo useth to denote theseStars, which futes not with the Number nor the Configuration that now ap-pears, do Administer caule to doubt, whether the Star in Qucstion be not oneof thole that appear from time to time.

XVI. 1. Supponit Cl. Cajsmus, ad Planetam in Ellipsi moventem extendiab utroque Foco duas Rectas, quarum altera sit Medii,- altera autem VeriMotus Linea. Constructio porro talis est:

L est Centrum Concentrici A B C D E.

BLD est Diameter.

B A, B C, B P, sunt Intervalla Ap-parentia.

D E, D F, D (i sunt Intervalla Me-diorum Motuum.

B E, B F, B CL; item DA, D C,D P, sunt Linere Recta;.

B E secat DA in N ; B F secat D Cin O; B CL secat D P in R.

RHG est Linea Recta.

BI est Perpendicularis ad RHG.I est Centrum Ellipfcos.

H est Excentriciras.

IO — LI.

O est Focus, circaMedius motus ;

Verus.

IM = IN=LB.

M, est Apogeon ;

To find ihr A*phclia of thePUnets dircftly ;ty M. Calliiu.Confidered byMr. Nie. Mer-cator.

n. 57. f . 1168. -

F‘S> n/.

quemL, circa

ordinatur-quem

BLM, Anomalia Vera.

N, Perigeon ;

Demonstratio. 1. lllustrillimus ac Revcrendiff. .Ssthus X ardas, Episcopus Saris-luriensts, in Examine Astronomia; Philolaicx, docuit Methodum, ex data Ano-malia Media Planetarum, investigandi Verum ; qua; est hujusmodi.

C. est Centrum Ellipseos AEP ; F, secus circa quem ordinatur Medius' Kj. 1:»Motus. 8, focus circa quem ordinatur Verus Motus. A, Apom-on.

P, Perigeon. E, Erro sive Planeta. A F E, Anomalia Media. A S E, Ano-malia Vera. FET, Linea Recta ; ETrrrSE. ST, est Linea Recta.

In Triangulo 8 F T, dantur, 1. SF, distantia locorum; z. FT — FE- 4 -ES — AP. z. AFT, Angulus Externus, sive Anomalia Medii, squa-lis Summte Angulorum EST & T. Ergo inveniri potest F SE, sive Ano-malia Vera, aequalis Differentiae Angulorum, FST & T. Kimimtu.

Ut Scmi-Jumina Laterum F F Ö f S, ad femi-differentiam corundan j haTangens firni-fumm «t Angulorum EST C? T, ad Tangentem, stmi-differentiaeorundem.

Sed Semi-summa laterum FT & FS Invenitur, substituendo pro FI’xqualem AP, cujus Semis est AC, qui additus C S, semiifi ipffus F S, sackSemi-lümmam AS, Distantiam Planet« Maximam.

Tuta

V