The Armillary Sphere, A Blueprint

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[SIZE="6"]The Armillary Sphere[/SIZE]




[SIZE="5"]A Blueprint to the creation of a faithful reproduction of Toril and its surrounds.

By Manannan Maiea, The Magnificent
Wyrm-Watcher
Hedge-Wizard
1382[/SIZE]

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Introduction

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[SIZE="4"]Any skilled observer of the heavens above will eventually begin to note how it is that the stars and planets, with a few exceptions, follow a vaguely circular pattern around the night sky.  Sometimes their voyages can also be seen to be nearer, or closer as proven by changes in the brightness as seen through looking glass or with the aid of magic.

Indeed, it is only the stars in the far north or south, nearest to the poles of Toril that do not travel at all, and the anomylous Wandering Star that offer any challenge to the trained Astronomer.  Of the rest, observation and practiced recordkeeping are all that is required to allow the calculation of the position, at any given time, of the celestial objects in the near, or even far environs of Toril.

To this knowledge, add a smattering of engineering.  Some rods, struts, gears, cogs and pins, and you find yourself at the beginnings of an understanding as to how one might replicate all the Cosmos, in Brass.

The Armillary Sphere.[/SIZE][/tface]

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[tface=FellSC][SIZE="5"]Legend, and Meaning of the Orbits[/SIZE]

[INDENT][INDENT][SIZE="4"]A. - Equinoctial ring, showing the sun’s ascension (Ψ).
[FONT="Arial"]b.[/FONT] - North pole nut holding the sun (Ψ).
B. - Ecliptic ring, showing location of the sun on a specific day.
C. - Northern Tropic.
[FONT="Arial"]d.[/FONT] - Pin holding the moon (Selune).
D. - Southern Tropic.
[FONT="Arial"]e.[/FONT] - Where Northern Tropic touches ecliptic.
E. - Auril's circle.
[FONT="Arial"]f.[/FONT] - Where Southern Tropic touches ecliptic.
F. - Base of the World.
G. - Celestial Median.
H. - Solstitial Median.
J. - Terrestrial globe.
K. - Terrestrial axis.
L. - Flat celestial meridian.
M. - Movable horizon.
[FONT="Arial"]n.[/FONT] - Terrestrial north pole.
N. - Celestial north pole.
N. - Pedestal.
O. - Joint.
P. - Arc of joint O (0 to 90 degrees).
Q. - Brass arm.
[FONT="Arial"]r.[/FONT] - Elevation screw.
R. - Upright piece.
[FONT="Arial"]s.[/FONT] - Terrestrial south pole.
S. - Celestial south pole.
T. - Box.
U. - 1st of 2 axes of wheels for T (turns).
V. - 2nd of 2 axes of wheels for T (turns).
W. - Winch.
Ψ. - Sun (Lathander).
Ζ. - Moon (Selune).[/SIZE][/tface][/INDENT][/INDENT]

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Conclusion

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[SIZE="4"]By this construction, the machine is equally fitted to show either the real motion of the earth, or the apparent motion of the heavens.

To rectify the sphere for use, first slacken the screw [FONT="Arial"]r[/FONT] in the upright stem R, and taking hold of the arm Q, move it up or down until the given degree of latitude for any place be at the side of the stem R; and then the axis of the sphere will be properly elevated, so as to stand parallel to the axis of the world, if the machine be set north and south by a small compass: this done, count the latitude from the north pole, upon the celestial meridian L, down towards the north notch of the horizon, and set the horizon to that latitude; then, turn the nut [FONT="Arial"]b[/FONT] until the sun Y comes to the given day of the year in the ecliptic, and the sun will be at its proper place for that day: find the place of the moon's ascending node, and also the place of the moon, by an Ephemeris, and set them right accordingly: lastly, turn the winch W, until either the sun comes to the meridian L, or until the meridian comes to the sun (according as you want the sphere or earth to move) and set the hour-index to the XII, marked noon, and the whole machine will be rectified. â€" Then turn the winch, and observe when the sun or moon rise and set in the horizon, and the hour-index will show the times thereof for the given day.[/SIZE][/tface]

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Copies of this tome are periodically dusted, and re-catalogued.