Cammenga PRECISION LENSATIC Instructional Booklet page 14

Coordinates are determined using the North/South and
East/West lines on a map (grid lines). Positions are
determined on a map by intersecting coordinates. The lower
left is the origin and coordinates are read to the right and then
up. (see fig. 5)
The position of "X" is read 04-24. Read the number from the
left to the right, then from the bottom to the top. For greater
accuracy, each of the boxes created by the grid lines can be
divided into 10 imaginary lines in both directions. Since the
position of "X" is not directly on one of the grid line
intersections, repeat the steps explained above with these
imaginary lines. The position of "X" would then be read
045-245.
12
28
27
26
25
24
23
22
21
20
1 2 3
(FIGURE 5)
X
4 5 6 7 8 9