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   First,  a check-box is provided to let you turn the marking in question
on or off.

   The currently set spacings in declination and right ascension will
have check marks beside them.  This menu lets you adjust the spacing
and epoch of the marking.

   By default,  the menu will show "Automatic Spacing" checked.
This means that Guide will judge the ideal spacing for the amount
of area covered by a given chart, using a small spacing for small
fields of view and a larger spacing for large fields.  You will
probably be content to leave automatic spacing on at first.  If you
would like to override Guide's judgment, click on the spacing
desired in each column, and automatic spacing will be turned off.
After having adjusted the spacing to what you think it should be,
you can click "Automatic Spacing" on again, and Guide will follow
your judgment when you change levels.
                                          
   Similarly,  by default,  the marking will be shown in the J2000.0
epoch.  Click on the Epoch line, however, and you will be prompted to
enter the new epoch for this marking. The fact that different markings
can use different epochs allows you to,  for example,  use a J2000.0
grid with B1950.0 ticks.
                                                       
   Also,  by default,  all markings are in equatorial coordinates
(that is,  they define spacings in RA/dec).  But you do have the  
option of selecting ecliptic,  alt/az (horizon),  or galactic     
coordinate markings instead.  Finally,  you'll notice a box to select
the color of the marking in question.

   The remaining seven items each bring up fairly simple submenus,  in
which only the color selection and "on/off" radio buttons are available.
The only exception is the "Aperture" option.  This option lets you specify
the size of a circle,  to be drawn superimposed at the center of the
chart.  In this case,  the submenu lets you enter the size of this circle.

   This is usually used to show the apparent angular field of view of a
telescope.  For example,  if your telescope has (with a particular
eyepiece) a .74 degree field of view,  you could turn the aperture on
and set that size.  The resulting circle would let you see how much of
the sky is visible,  at a given time,  with that telescope/eyepiece.

   In entering the aperture size,  you can also enter 15' for a 15
arcminute circle,  or 45.3" for a 45.3 arcsecond circle.

   Also:  when any of these objects appears on-screen,  you can adjust
its display by right-clicking on it,  then clicking "Display".  The
only time it is truly necessary to go through the "Ticks,  Grids,
Etc." menu option is when the object type you want isn't on screen
(perhaps because it is turned off.)

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