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.

About this Item

Title

Author

Sturmy, Samuel, 1633-1669.

Publication

London :: Printed by E. Cotes for G. Hurlock, W. Fisher, E. Thomas, and D. Page ...,

1669.

Rights/Permissions

To the extent possible under law, the Text Creation Partnership has waived all copyright and related or neighboring rights to this keyboarded and encoded edition of the work described above, according to the terms of the CC0 1.0 Public Domain Dedication ( http://creativecommons.org/publicdomain/zero/1.0/). This waiver does not extend to any page images or other supplementary files associated with this work, which may be protected by copyright or other license restrictions. Please go to http://www.textcreationpartnership.org/ for more information.

This text has been selected for inclusion in the EEBO-TCP: Navigations collection, funded by the National Endowment for the Humanities.

Link to this Item

http://name.umdl.umich.edu/A61915.0001.001

Cite this Item

"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." In the digital collection Early English Books Online 2. https://name.umdl.umich.edu/A61915.0001.001. University of Michigan Library Digital Collections. Accessed June 22, 2025.

Pages

PROBL. IV. The Elevation of the Pole, and Declination of the Sun being given; to find the Ascentional-Difference.

THis is represented in the Figure by SL in the Parallel of Declination, and it is therefore to be reduced into the common Radius, therefore take the Radius of the Parallel ST, and prick it from C to X, as before; then take the extent SL, and setting one Foot upon X, with the other draw the part of an Arch at a, lay a Ruler from C, that it may just touch the outside thereof, and it cuts the Circle in d, and take the Chord or Extent Hd; and you will find it 28 deg. 0 min. which being con∣verted into Time, is an Hour 52 min. and so much doth the Sun Rise before, and Set after Six in Summer; but so much doth he Rise after, and Set before Six in Winter, when he hath the same Declination South.

In the Right-Angled Spherical Triangle SLC are known. 1. SCL the Com∣plement of the Poles Elevation 38 deg. 32 min. 2. The Suns Declination 20 deg. 30 min. hence to find the Ascentional Difference SL.

As the Radius 90 deg. is in Proportion	10
to the Tangent of the Latit. 51 deg. 28 min. SCL	1009887
So is the Tangent of the Suns Declination 20 deg. 30′ SC	957273
to the Sign of SL the Ascentional-difference 28 d. 00 m.	967160

Extend the Compasses on the Artificial-Lines of Signs and Tangents, and you will find it, as before; or if you take the distance NS, and prick it from S to K, and lay the Ruler from Cover L, it will cut the Arch of the Meridian in d; then Measure the distance Nd on the Line of Chords, and it will be 28 deg. 00 min. as before found, that is one Hour 52 min.