The arte of nauigation wherein is contained all the rules, declarations, secretes, & aduises, which for good nauigation are necessarie & ought to be knowen and practised: and are very profitable for all kind of mariners, made by (master Peter de Medina) directed to the right excellent and renowned lord, don Philippe, prince of Spaine, and of both Siciles. And now newely translated out of Spanish into English by John Frampton. 1581.

The nienth Chapter, how the altitude of the North, is to be taken, although the Hori∣zon be not seene.

IT happeneth manye times to suche as sayle, that they cannot take y^e altitude of the North, because they cannot see the Horizon. This is be∣cause either the earth doth couer it, or

some cloude or vapour which riseth of the water, or it maketh so much dark∣nesse, that it cannot bee discerned, or for some other cause. And howe to know y^e Horizon is a thing so necessary, that lac∣king it the altitude of the North cannot any manner of way bee taken with the Ballestilla of this cause the saylers re∣ceiue very great hurte, for that manye times it happeneth to them, to passe many dayes without taking the alti∣tude and most of all in the winter.

Therefore to take away this hurte & inconuenience, I will declare in this present Chapter, in what manner the sayde altitude may bee taken although the Horizon be not seene, the which is this. The pilot or other person, that shoulde take this altitude, let him take a staffe or rodde of the greathes of a fin∣ger little more or lesse, and so high, that beeyng put vpright in the grounde, it come iustly to his sight, and beeyng made of this greatnesse, no more nor lese: let him make at the toppe of it a Crosse, and when hee will take the alti∣tude, let him ioyne his feete together, and laye downe the rodde straight and equall from the poynt of his feete, as farre as the rodde will reache, and let him make two poyntes, the one where he hath his feete, and the other as farre as the rodde doth reache, and in that poynt where the rodde doth reach, there doe you take him vp, and let some bodye holde him vpright, and the Bal∣lestilla beeyng taken his feete beeyng put in the poynt that he first had them put, let him take his altitude, making the Horizon in the highest parte of the rodde or staffe where hee marked the Crosse. And yee shall vnderstand that this is his Horizon, wheresoeuer hee findeth himselfe. And it is to be noted, that if the night were as darke, that y^e highest parte of the rodde cannot bee seene. That which I haue saide is his Horizon, then put vpon the toppe of the rodde, a signe or shew of fire, by the sight of the which hee may hit to put his Ballestilla right with the sayd rod, and so he shall take his altitude precise∣ly doing in the rest, to take away or put to the degrees, according to the place wherein the guardes are, as before hath beene declared.