The theoriques of the seuen planets shewing all their diuerse motions, and all other accidents, called passions, thereunto belonging. Now more plainly set forth in our mother tongue by M. Blundeuile, than euer they haue been heretofore in any other tongue whatsoeuer, and that with such pleasant demonstratiue figures, as euery man that hath any skill in arithmeticke, may easily vnderstand the same. ... VVhereunto is added by the said Master Blundeuile, a breefe extract by him made, of Maginus his Theoriques, for the better vnderstanding of the Prutenicall tables, to calculate thereby the diuerse motions of the seuen planets. There is also hereto added, The making, description, and vse, of two most ingenious and necessarie instruments for sea-men ... First inuented by M. Doctor Gilbert ... and now here plainely set downe in our mother tongue by Master Blundeuile.

¶The second figure belonging to the Theorique of the Moone.

[illustration]

IN which figure the circle F C E K signifieth the plane of the Eclipticke, and the centre thereof is marked with the point A: and the circle F B E I signifieth the plane of the deferent of the Epicicle, in the circum∣ference whereof is the centre of the first Epicicle, mar∣ked with the letter L; and in the circumference thereof is the centre of the second Epicicle, marked with the let∣ter M, and in the circumference thereof is the character of the Moone: and the centre of the deferent of the Epi∣cicle, is the same which the Eclipticke hath, that is to say, the centre A; and this circle crosseth the Eclipticke in two opposit points, that is to say, in the point F and E, called the Nodes, the one of which is called the head of the Dragon, marked with this caracter 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, and the other is called the taile of the Dragon, marked with this cara∣cter

〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉. Vnto either of which two Nodes when the Moon commeth, then she is in the Eclipticke, and in her moo∣uing from either of the said two Nodes shee goeth fur∣ther and further from the Eclipticke, vntill she come to one of the 2 limits of her latitude either North or South.

3. Whereof her North limit is marked in this figure with the letter B, and her South limit with the letter l, either of which limits is neuer more distant from the Ecliptick than fiue degrees, but from the Nodes each limit is di∣stant 90 degrees.

4. And hereby you may gather, that the two Nodes are nothing els but two points, in which the plane of the deferent of the Epicicles dooth crosse the plane of the Eclipticke. And the one of these Nodes is called the ascending Node or head of the Dragon, and the o∣ther is called the descending Node or the taile of the Dragon.

5. The head of the Dragon is that Node, vnto which when the Moon commeth, she beginneth to go North∣ward from the Eclipticke: and that Node is marked with this caracter 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉.

6. The taile of the Dragon is that Node, vnto which when the Moone commeth, she beginneth to go South∣ward from the Ecliptick, which Node is marked with this caracter 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉.

7. The line of the mean or true mouing of the Nodes is a line drawne from the centre of the world vnto any of the said Nodes: as in the former figure the line A F signifieth the line of the mouing of the head of the Dra∣gon, and the line A E signifieth the line of the mouing of the taile of the Dragon.

8. The meane mouing of the Nodes is an arch of the

Eclipticke, beginning at the first star of the Rams home or at the first true Vernall Equinox, and endeth at the line of the mouing of the Node, so as the said arch bee reckoned contrarie to the succession of the signes.

9. The true moouing of the Nodes is an arch of the Eclipticke, beginning at the first starre of the Rams horn, if the same be reckoned in the Eclipticke of the eight Heauen, or at the true Vernall Equinox, if the same bee reckoned in the Eclipticke of the first mouable, and en∣ding at the line of the mouing of the Node, so as the said arch be numbered according to the succession of the signes.

10. The line of the meane mouing of the Moone is a line drawne from the centre of the world through the centre of the first Epicicle, and so forth vnto the Eclip∣ticke. As for example, in the first figure the right line A E B is the line of the meane mouing of the Moone.

11. The place of the centre of the first Epicicle in the Eclipticke, is that point in which the line of the meane mouing of the Moone falleth in the Eclipticke. As in the said first figure the point B in the Eclipticke is the place of the centre of the first Epicicle.

12. The meane simple moouing of the Moones lon∣gitude, is an arch of the Eclipticke, beginning at the first starre of the Rams horne, and ending at the place of the centre of the first Epicicle. As in the said first figure the arch * H K is called the mean, equall, or simple mouing of the Moones longitude: and the daily mouing of this simple longitude is 13 degrees, ⁱ ₁₀· ⁱⁱ ₃₄· ⁱⁱⁱ ₅₃· and according vnto this motion the Moone maketh her reuolution in 27 dayes, 7 houres, ⁱ ₄₃· ⁱⁱ ₇· for in this time shee returneth vnto the first starre of the Rams horne, and this is called

the Periodicall moneth. As in the first figure the arch * H K is the equall simple mouing of the longitude of the Moone.

13. But if the said motion dooth begin at the meane place of the Sunne, that is, at the line of the meane mo∣uing of the Sunne, then is it called the equall or meane longitude of the Moone from the Sunne, and then the daily motion is 12 degrees ⁱ ₁₁· ⁱⁱ ₂₆· ⁱⁱⁱ ₄₁· and according vn∣to this, the Moone maketh her reuolution in 29 dayes, 12 houres, ⁱ ₄₄· ⁱⁱ ₃· and the time of this reuolution is called the Synodicall moneth. So as if you subtract the equall simple moouing of the Sunne out of the equall simple moouing of the Moones longitude, the remainer will shew the meane longitude of the Moone from the Sunne. As in the said first figure suppose the arch * H to be the equall simple mouing of the Sunne, and the arch * H K to be the equall simple moouing of the Moones longitude. Now if you subtract * H out of * H K, the remainer will be H K, and that is the meane longitude of the Moone from the Sunne. And the finding of this at any time giuen, is taught in the 8 Precept, by helpe of the 13 and 14 Cannons, in the Collume whose title is Longitudo media à Sole.

14. And againe, sometimes the meane moouing of the centre of the first Epicicle or of the Moone, is ac∣counted to begin at the North limit, and then is it called by Ptolomey and Copernicus the mean motion of the lati∣tude of the Moone; because that after the same be corre∣cted, it sheweth the true latitude of the Moon: & the fin∣ding of this motion at any time is to be found in such or∣der as is shewed in the 8 Precept, by help of the 13 and 14 Cannons in the Colume, whose title is Latitudinis Lunae.

15. But Alphonsus and his followers make the begin∣ning of the said motion to be at the head of the Dragon, and is called by them the Argument of the latitude of the Moone, and the daily motion of the Moons latitude is 13 degrees, ⁱ _1•° ⁱⁱ ₄₅· ⁱⁱⁱ _•9· and according vnto this moti∣on she maketh her reuolution in 27 dayes, 5 houres, ⁱ ₅· ⁱⁱ ₃₆· And the Argument of the Moones latitude is to be sound at any time giuen, by adding of 90 degrees vnto the mean motion of her latitude: the manner of the fin∣ding whereof was shewed in the 14 definition of this Chapter.

16. And you haue to note, that according to the mo∣tion of the deferent of the Epicicle, the centre of the Epicicle is imagined to describe a circle in the middle of the said deferent: which circle is called the circle of the mouing of the centre; and this circle is signified in the first figure by the white circle in the middle of the blacke deferent of the Epicicle, described by the centre of the first Epicicle.

17. The first Epicicle is an orbe in the Theorique of the Moone, which continually carieth about the second Epicicle of the Moone. This orbe hath his owne proper motion about his owne poles and axletree, which axle∣tree is perpendicular vnto the plane of the deferent of the Epicicle, and is paralell vnto the said axletree of the said deferent: wherby it commeth to passe, that the plane of this first Epicicle is alwaies in the plane of his deferent. And the motion of this Epicicle is contrary to the suc∣cession of the signes, and the daily motion thereof is 13 degrees, ⁱ ₃· ⁱⁱ ₅₃· ⁱⁱⁱ ₅₆· and maketh one entire reuolution in 27 dayes and 13 houres almost: and the semidiameter of this Epicicle is 6 degrees, ⁱ ₃₅· whereof the semidiameter

of the mouing of his centre containeth 60.

18. The Auge of the first Epicicle is a point in the superficies thereof, which is furthest distant from the cen∣tre of the earth. And the opposit Auge is that point which is nearest vnto the centre of the earth. And the Auge and opposit Auge is determined by a right line drawne from the centre of the earth vnto the circumfe∣rence of the said first Epicicle, through the centre of the same. As in the first figure the point B is the Auge of the first Epicicle, and the point C the opposit Auge thereof.

19. The meane Anomalia of the Epicicle, which is otherwise called the meane Argument, is an arch of the first Epicicle, containing the distance betwixt the centre of the second Epicicle, and the Auge of the first Epici∣cle. And this is determined by a right line drawne from the centre of the first Epicicle vnto the centre of the se∣cond Epicicle, as this figure next following sheweth.