M. Blundevile his exercises containing sixe treatises, the titles wherof are set down in the next printed page: which treatises are verie necessarie to be read and learned of all yoong gentlemen that haue not bene exercised in such disciplines, and yet are desirous to haue knowledge as well in cosmographie, astronomie, and geographie, as also in the arte of navigation ... To the furtherance of which arte of navigation, the said M. Blundevile speciallie wrote the said treatises and of meere good will doth dedicate the same to all the young gentlemen of this realme.

Of the right, oblique, and meane ascention in particular, and of the chiefest causes of such diuersitie of ascentions. Chap. 32.

ANd for the better vnderstanding of the Astro∣nomicall ascention and descention, wee will make this diuision, for either it is of some point or starre, or else of some portion of a Circle chiefely of the Ecliptique line. In the ascention of any point or starre, wee consider two thinges. First what Angle it maketh with the Horizon either right or oblique. Secondly the time from the rising of the first minute of Aries, which is the first beginning of the Longitude of any starre or Circle in heauen, and in respect of the Angle euery ascention is sayd to be right in a right Spheare, and oblique in an oblique Spheare: A∣gaine the time of the ascention is to be measured by the degrées of the Equinoctiall from the first minute of Aries, vnto that degrée and minute of the Equinoctiall which ascendeth together with the starres, And note by the way that 15. degrées of the Equi∣noctiall do make an houre, and foure doe make one degrée of the same Equinoctiall, for foure times 15. doe make 60. minutes, which is an houre, Againe euery ascention considered, according to the time of his gate, is eyther right, oblique, or meane: if it be right, it is slowe: if it be oblique, it is quicke: if it be meane, it is equall. Now the ascention of any Arke or portion of a Circle is also eyther right, oblique, or meane: if it be right, it ascendeth slowely: if oblique, it ascendeth quickely: if meane, it ascendeth equally. And the better to vnderstand all these thrée kindes of as∣centions, I will set downe these twelue rules heere following, whereof fiue doe belong to the right Spheare, and seuen to the oblique.

In the right Spheare all the foure quarters rising from the foure principall points, haue a meane ascention, and so hath all the foure points themselues.

In the right Spheare all those signes that be equally distant from the foure principall points haue equall ascentions.

3 In the right Spheare all starres or pointes that be in the Sol∣sticiall Colure haue meane ascention.

4 In the right Spheare those signes that do ascend rightly, doe descend rightly, and those that doe ascend obliquely, doe descend obliquely.

5 In the right Spheare, Gemini, Cancer, Sagittarius, and Capricornus, doe ascende rightly, and all the rest obliquely.

6 In the oblique Spheare, the two Equinoctiall points haue meane ascention.

7 In the oblique Spheare ech halfe of the Spheare, beginning at eyther of the Equinoxes haue meane ascention: but this rule holdeth not, if that you beginne any other where.

8 In the oblique Sphere, those signes that do ascend rightly, do descēd obliquely, & those which ascend obliquely do descēd rightly.

9 In the oblique Spheare, the ascention of any supposed signe is equall to the descention of his opposite signe, and the descen∣tion of any supposed signe, is equall to the ascention of his op∣posite signe.

10 In the oblique Spheare, the ascention of any signe being ad∣ded to his descention, is equall to the ascention and descention of the same signe being in the right Spheare.

11 In the oblique Sphere euery two signes equally distant from the two points of the Equinoctiall, haue equall ascentions and descentions.

12 In the oblique Sphere vnder the pole Arctique, al signes from Cancer to Capricorne, do ascend rightly, and all the rest oblique∣ly, but contrariwise vnder the Pole Antarctique.

What is the chiefe cause of the diuersity of ascentions and descentions, aswell in the right as in the oblique Spheare?

The chiefe cause is the diuersity of the Angles which the Zo∣diaque maketh with the Horizon, for the sharper that the Angles be the lesser portion of the Equinoctiall riseth together with the Ecliptique, and the righter that the Angles be, the greater porti∣on of the Equinoctial riseth, but the Equinoctiall by reason of his vniformitie, maketh his Angles alwayes equall one to another, that is to say, in the right Spheare, it maketh right Angles, and in the oblique Spheare, though not right, yet in euery signe it maketh like Angles.