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.

Another example of counting the way of your shippe in sayling right East. Chap. 36.

SVppose then that you haue to sayle from the newe found lande right East in the Parallel of 50. degrées: and hauing caused your houre glasse to begin to run iust at noone, you set foorth and sayle the space of 15. dayes, not forgetting euery day once to turne your houre glasse. Now if at the 15. dayes end, you would know how many leagues you haue sayled, to finde in your Card in what place you are, you must first tarrie vntill your houre-glasse be cleane runne out, and at that instant séeke by your Astronomicall ring, or by some vni∣uersall Dyall, to know what houre it is, which because you haue sayled right East, you finde to be two houres and twelue minutes afternoone, then resorting to the Table aforesaide, you finde in the third colum the 50. degrées of altitude, together with the num∣ber 168. leagues and a halfe, annexed to the saide degrée for one houre of that Parallell, which summe being multiplyed by two houres, maketh 337. leagues, then multiply once againe 168. by the odde 12′· and deuide the product thereof by 60. so shal you find in the quotient 33. leagues and somewhat more, which being added to the former summe 337. leagues will make in all 370. leagues and a little more, and that is the true quantitie of your voyage. And Cogniet sayth that by practizing this way of coun∣ting, you may know euery day, yea euery houre, what way your shippe maketh in sayling right East or West.