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 find out the right ascention of the sunne, or of any degree or portion of the Ecliptique. The 12. Proposition. (Book 12)

TAke the Rete and the label cleane from the Astro∣labe, and séeke out in the Ecliptique line of the mater the signe and degrée whose right ascention you would know, and marke what Meridian cut∣teth that point: that done, place the labell vpon the pinne which standeth in the very Centre of the Iewell, and make the fiduciall line thereof to lie right vppon, and alongest the Equinoctiall line eyther towardes your right hand or towards your left, according as the signe & degrée whose ascention you séeke is placed in the mater. Then marke where the foresaid Meridian cutteth through the labell, and also through the

Equinoctiall line, and the number of degrées contained in the labell, betwixt the Centre and that point of the Equinoctial is the right ascention of that degrée of the Ecliptique which you séeke, which number of degrées you must count vpon the labell in this maner. For if that signe and degrée be contained betwixt the first point of Aries and the first point of Cancer, then you must begin to count vpon the labell at the Centre, and so procéede forwarde towards Cancer, the right ascention of whose first point is 90. de∣grées, but if the signe and degrée which you séeke, be betwixt the beginning of Cancer and the beginning of Libra, which is at the very Centre right against Aries, then you must count vpon the labell backward from 90. to 180. by adding to euery tenth space of the labell 10. degrées, so as the first number procéeding towards your left hand shall be 100. and next to that 110. and so foorth vntill you come to 130. which is the right ascention of the first point of Libra, and from Libra you must count towards Ca∣pricorne 190. then 200. and so foorth till you come to 270. which is the right ascention of the first point of Capricorne: and from thence you must count 280. 290. then 300. and so foorth towards the Centre vntill you come to 360. which is the right ascention of the last point of Pisces, so as though there be set downe in the labell but 90 degrées both forward and backwarde, yet 90. being foure times repeated, doe make in all 360. which is the whole Longitude of the Equinoctiall. As for example, you would know perhaps the right ascention of the tenth degrée of Sagittarius, here by séeking in the mater you shall find that the Meridian pas∣sing through that degrée will cut both the labell being layde to∣wards your left hande, and also the Equinoctiall in the 248. de∣grées 21. minutes, which is the right ascention of the tenth de∣grée of Sagittarius, in counting whereof remember to beginne from 180. that is from the Centre, and this ascention agréeth with the Table of right ascentions set downe in Stadius his E∣phemerides the 44. page of his booke. Againe in séeking to know the right ascention of the 10. degrée of Taurus, if you beginne to count vpon the labell from the Centre, which is the first point of Aries, you shall finde that the Meridian which passeth through the 10. degrées of Taurus will cut the labell, and the Equinoctiall line in the 37. degrée 35′·