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.

EXAMPLE I. Of those that are more Easterly, which increase in Declination.

On the 26th of March, the first Year after the Leap-year, I desire to know the Declination of the Sun at Noon at Bantam in the East-Indies. 〈 math 〉〈 math 〉 I find by Globes, or the Plat of Mercator, that Bantam is to the Eastward of the Meridian of London about 110 Degrees; we do not esteem of a Degree or two, because it amounteth to nothing in this Practice. The Sun for his Course round the Heavens and Earth, which is 360 Degrees, hath need of 24 Hours; What time will 110 Degrees have? Facit 7 Hours, and something more not worth the noting; whereby the Sun comes to the Meridian 7 Hours sooner at Bantam, than it doth at London; That it is 12 a Clock at Noon at Bantam, when it is 4 of the Clock in the Morning with us at London. The Sun's Declination for the 26th of March, is 6 deg. 25 min.: The Difference of the Declination of the Day following, you find is 23 min. which it is increased; Therefore I say, If in 24 Hours the Declination increaseth 23 Minutes, How much then in 7 Hours? Facit almost 7 Minutes, that the Declination is less than it is at London. So that the Declination at Bantam that Day, is but 6 deg. 18 min. North: And on the contrary, when the De∣clination decreaseth, work, and you will have the Declination South, Eastward, or Westward.