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.

How to finde out the right and oblique ascention of any starre, and also of the ascentionall difference. The 32. Proposition.

THe right ascention of any star is an arch or portion of the Equator, to be counted from the first point of Aries according to the succession of the signes, with which portion in a right Spheare any starre both riseth mounteth to the Meridian, and setteth: and in an oblique Spheare it is a portion of the Equator, wherewith the star is mounted to the Meridian: as for example, in a great Spheare the star called Cor Leonis, that is to say, the hart of the

Lion, both riseth, mounteth and setteth with the 145. degr. 30′· of the Equinoctiall. But the right ascention of the said starre in an oblique Spheare, is to be found onely by bringing the said starre to the Meridian, and you shall find it to be all one with the right ascention in a right Spheare, for by bringing the starre called Cor Leonis to the Meridian in an oblique Spheare, you shall finde the right ascention thereof to be all one with that which it had in a right Spheare, that is 145. degrées 30′· of the Equi∣noctiall. But if you would know the oblique ascention of any star, then hauing set the Globe at your Latitude, bring the starre to the East part of the Horizon, & marke what degrée of the Equinoctial

riseth therewith and that is the oblique ascention: As for example, the Globe standing at the Latitude 52. bring the starre, Cor Leo∣nis to the East part of the Horizon, & by staying the Globe there, you shall find the 127. degrée of the Equinoctiall to rise with that starre. Now if you would know the ascentionall difference, that is to lay, the difference betwixt the right and oblique ascention, you haue no more to doe but to subtract the lesser out of the grea∣ter, and the remainder shall be the ascentionall difference, as in the former example, take 127 degrées out of 145. degrées and 30′ and there shall remaine 18. degrées 30′· and that is the ascentio∣nall difference, by helpe wherof you may know the encrease and decrease of the artificiall day and night throughout the yeare in any Latitude, if you obserue that order which I haue already set downe in the first part of my Spheare, the 50. Chapter.