The mariners magazine, or, Sturmy's mathematical and practical arts containing the description and use of the scale of scales, it being a mathematical ruler, that resolves most mathematical conclusions, and likewise the making and use of the crostaff, quadrant, and the quadrat, nocturnals, and other most useful instruments for all artists and navigators : the art of navigation, resolved geometrically, instrumentally, and by calculation, and by that late excellent invention of logarithms, in the three principal kinds of sailing : with new tables of the longitude and latitude of the most eminent places ... : together with a discourse of the practick part of navigation ..., a new way of surveying land ..., the art of gauging all sorts of vessels ..., the art of dialling by a gnomical scale ... : whereunto is annexed, an abridgment of the penalties and forfeitures, by acts of parliaments appointed, relating to the customs and navigation : also a compendium of fortification, both geometrically and instrumentally / by Capt. Samuel Sturmy.

PROBL. X. The Elevation of the Pole, and Declination of the Sun being given, to find the Suns Altitude at the Hour of Six.

TAke the nearest distance from S to the Horizon CL, and apply it to the Line of Signs, sheweth the Altitude to be 15 degr. 54 min. or the same taken of the Con∣cave-Sphere, and measured on the Line of ½ Tangents, sheweth the same; and so much is his Depression under the Horizon at Six, when he hath South-Declination 20 degr. 30 min.

In the Concave-Sphere, you may see all the Triangles plain, and we have known in this Triangle ZSN, (1.) The Complement of the Latitude ZN 38 degr. 32 m. (2.) the Complement of the Suns Declination NS 69 degr. 30 min. to find the Hypotenase ZS; therefore I say,

As the Radius 90 degr. is in Proportion	10
To the Co-Sign of 69 degr. 30 min. NS	954432
so is the Co-Sign of 38 degr. 32 min. ZN	989334
To the Sign of the Altitude 74 degr. 6 min. S 00	943766

Whose Sign is 15 degr. 54 min. is the Suns Altitude at the hour of Six, when he is 1 degr. 18 m. of ♐ in Latitude 51 deg, 28 m. Extend the Compasses from 90 degr. to 20 d. 30′, the same extent will reach from the Latitude 51 deg. 28 min. to 15 deg. 54 m. as before.