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shown in the legend,  and Guide will let you choose a constellation
on which to recenter the chart.  Clicking on the hours shown in the
time in the legend adds or subtracts one hour from the current time
used by Guide (adds an hour for a left-click,  subtracts an hour for
a right-click.)  As you move the mouse over the legend,  Guide's
title bar will tell you what action a click on that point would do.

4:  PANNING AND ZOOMING                            

   To move to another part of the sky, you can move the mouse cursor to
somewhere else on the chart area,  and click on the LEFT mouse button.
A chart will be drawn at the same scale,  but centered at the point you
clicked on. Click on the center of the top of the chart, and you will
see a smaller version of the Big Dipper, with its brightest star at the
tip of the handle. This is Ursa Minor, the Small Bear or Little Dipper.
The bright star is the North Star, Polaris. The arcs of the
constellation boundaries center on (well, very close to)  this star; it
marks the celestial the North Pole. It's only coincidence that gives us
a fairly bright star near the pole right now; the South Pole has no
such luck,  and at many times in the past, no bright star has been near
the North celestial pole either.
                
   There are many ways to zoom out; you may for instance hit ,
the divide key. You will then see an area of the sky roughly twice
as large in both height and width. Because you see more sky, some
markings will be dropped out to avoid cluttering the screen: for
instance, the Bayer letters are now omitted. To zoom in, hit <*>,
the asterisk. You'll see the reverse of the Zoom Out process occur.
(The asterisk and division keys can be used at any time and at any
zoom level in the program: they are program-wide hotkeys. A list of
program-wide hotkeys is found on page 77;  or you can click on
Help... List Hotkeys,  or Settings... Toolbar.  This last option,
described in more detail on page 33,  also lets you reset hotkeys.)

   If you have a three-button mouse, you can click with the center
mouse button to combine recentering on that point with zooming out
one level.

   Usually,  whenever you zoom in or out, Guide tries to decide what
level of clutter you would like best. Stars will brighten or dim as
you zoom in or out, and dim stars will drop out as you zoom out and
appear when you zoom in. You can override Guide's judgment through
the Display menu.

   There are twenty "zoom levels" in Guide.  Level 1 is a full,  180
degree hemisphere field of view.  Level 2 defaults to a 90-degree
field,  and so on,  down to level 20 at .001 arcsecond.  (One will
rarely need such a field of view,  but it allows one to see even very
small outer planet satellites as disks,  or sometimes as lumpy
objects.)

   You can go directly to a particular level in four different ways.

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