Place the pinhole at the end of slot 3 (marked "4-6") at the end
of the second vector; stick a pin or sharp pencil through the
hole to hold the pinhole there; rotate the plotting scale until
the 1,600-mil line on the azimuth dial is parallel to any north-
south grid line and directed toward grid north; draw a line in
the 4-6 slot to 18 (18 knots) at the selected map scale. Mark
the end of this vector with the number 6 to indicate 6,000 meter
height and add a small circle (Figure 2-4).