Reading The Circle And Vernier; Sighting And Focusing The Telescope - David White L6-20N Owner's Manual

Reading the circle and vernier

The 360° horizontal circle is divided in quadrants (0-90°). The
circle is marked by degrees and numbered every 10 degrees. To
obtain degree readings, it is only necessary to read the exact
degree at the intersection of the zero index mark on the vernier
and the degree mark on the circle (or on the vertical arc of the
level-transit.)
75 degrees
For more precise readings, the vernier scale is used. The vernier
lets you subdivide each whole degree on the circle into fractions,
or minutes. There are 60 minutes in a degree. If the vernier zero
does not coincide exactly with a degree mark on the circle, note
the last degree mark passed and, reading up the vernier scale,
locate a vernier mark that coincides with a circle mark. This will
indicate your reading in degrees and minutes.
75 degrees,
45 minutes
Sighting and focusing
the telescope
Aim the telescope at the object and sight first along the top of the
telescope tube. Then look through the telescope and adjust the
focus.
When cross hairs are positioned on or near the target, tighten the
horizontal clamp and make final settings with the tangent to bring
the cross hair exactly on point.
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