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.

CANON TRIANGULORUM LOGARITHMICUS. OR, A TABLE of ARTIFICIAL SINES and TANGENTS to every Degree and Minute of the QƲADRANT. The Common Radius being 10,000000. By Capt. SAMUEL STURMY.

[illustration] geometrical diagram

The Description of the TRIANGLE.

Let ZPS represent the Zenith, Pole, and Sun, ZP being 38 deg. 30 min. Complement of the Latitude, PS the Complement of the Suns Declination 70 deg. and the Complement of the Suns Altitude ZS 40 deg. 00 min. the Angle at Z shall shew the Azimuth, and the Angle at P the Hour of the Day from the Meridian: Then if from Z to PS we let down a Per∣pendicular, as ZR, we shall reduce the Oblique Triangle into two Rectangled Triangles ZRP and ZRS: If from S to ZP we let down a Perpendicular SM, we shall reduce the same ZPS into two other Triangles, as SMZ and SMP Rectangled at M. Whatsoever is said of any of these Triangles, the same holdeth for all other Triangles in the like Cases.

London, Printed by E. Cotes, Anno Dom. 1669.