A tutor to astronomie and geographie, or, An easie and speedy way to know the use of both the globes, coelestial and terrestrial in six books : the first teaching the rudiments of astronomy and geography, the 2. shewing by the globes the solution of astronomical & geographical probl., the 3. shewing by the globes the solution of problems in navigation, the 4. shewing by the globes the solution of astrological problemes, the 5. shewing by the globes the solution of gnomonical problemes, the 6. shewing by the globes the solution of of [sic] spherical triangles : more fully and amply then hath ever been set forth either by Gemma Frisius, Metius, Hues, Wright, Blaew, or any others that have taught the use of the globes : and that so plainly and methodically that the meanest capacity may at first reading apprehend it, and with a little practise grow expert in these divine sciences / by Joseph Moxon ; whereunto is added Antient poetical stories of the stars, shewing reasons why the several shapes and forms are pictured on the coelestial globe, collected from Dr. Hood ; as also a Discourse of the antiquity, progress and augmentation of astronomie.

PROB. II.

To make an Equinoctial Dyal.

DIscribe a Circle, on a square board or Plane as B C E D, and through A the Center thereof draw a straight line Parallel to one of the sides, as B E; Cross that straight line with another straight line as C D at Right Angles, so shall the Circle be divided into 4 equal parts: Divide each of these four equal parts into 90. degrees; as in the Figure. This Circle shall represent the Horizon.

Erect a wyer exactly perpendicular to the Center of the Plane; and that wyer shall be the Gnomon or Style of the Dyal.

Then Elevate one of the Poles of your Globe into the Zenith, and bring the Equinoctial Colure to the Meridian. And because in every hours Time 15 degrees of the Equator passes through the Meridian in Heaven, therefore turn the Globe till 15 degrees of the Equator pass through the Meridian of your Globe; so shall the Colure pass by 15 degrees of the Horizon also. Therefore from the Center of your Plane draw straight lines through 15▪ degrees from one of the Semidiameters both waies: and those straight lines shall be two Hour-lines: Then turn the Globe till 15 degrees more of the Equator pass through the Me∣ridian, and you will find as before, the Colure pass by 15 degrees more of the Horizon: therefore on your Plane number 15. de∣grees further beyond both the former lines, and from the Center draw straight lines through both those 15. degrees, and they shall be two Hour lines more. Fór all the other Hour lines turn the Globe till 15. degrees of the Equator at a time pass through the Meridian, as before, and you will find that for every 15. de∣grees of the Equator that passes through the Meridian, the Colure will pass through 15. degrees of the Horizon: therefore those

Hour lines must be drawn from the Center according to the succession of every 15 degrees on your Plane, Having drawn the Hour lines, you may set figures to them, beginning to num∣ber your Hour lines from one of the Diameters, marking it with XII, and the next Hour line to the left hand with I, and the next II, the next III, &c. to XII. and begin again with I, II, III, &c. till you come to the other XII, where you began: and then your Dyal is finished. See the Figure.

[illustration]

This is an Universal Dyal, and serves in all Latitudes: therefore when you place it you must set one of the XII^s downwards, and the Axis Parallel to the Axis of the World.

But note, Both faces of this Dyal ought to be divided, and the Gnomon must appear on both sides like the stick in a Whir∣ligig, which childeren use; or else you must turn it upside down, so oft as the Sun passes the Equinoctial.