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.

PROPOSITION I. The Moon being 16 days old,* 1.1 I demand upon what Point of the Compass she will be at 8 of the Clock at night.

In all Questions of this nature you have the Hour and Time given, and the Moons Age, to find the Point of the Compass. To answer these Questions, place the middle Index of the Sun on 8 of the Clock at night; then bring the upper In∣dex of the Moon right over the 16th. day of her Age, in the middle Circle of the Sun, and the Index of the Moon or upper Circle points to E. b. S. half a point Southerly, the true Point of the Compass the Moon will be, when she is 16 days old, at 8 of the Clock at night.

[illustration] diagram of a compass

An Instrument Shewing y^e Changing of y^e Tides and y^e Variation of y^e Compas

Betweene fol: 6 & 7.

〈1 page missing〉〈1 page missing〉

Notes

• * 1.1

  Here the Variation Compass is to be placed.