36
MaP Design
one line; on the conic projection shown in Figure 2.21, the arrow cannot be used.
Unfortunately, improper use of a north arrow is a common error. Compass roses that
show the cardinal directions (north, south, east, west) are generally used for naviga-
tion maps and are not usually appropriate for thematic maps.
If used, north arrows, like scales, are aids to the reader and shouldn’t dominate
the map. Many companies or agencies use a small logo for the arrow center and this
can be effective, but still shouldn’t overpower the map. Figure 2.22 shows a variety
of north arrows and compass roses.
If parallels and meridians are drawn on the map a north arrow is redundant. The
Kilometers
0
5
10
Kilometers
0
5
10
0
10
15
Kilometers
5
Kilometers
5 0
45
90
fIgURe 2.20.
Graphic scales can be drawn in a variety of ways.
N
fIgURe 2.21.
North arrows should not be used if meridians radiate or curve. The arrow on
this conic projection does not point north.
Map Design 37
choice of number of parallels and meridians depends on the scale of the map and its
purpose. A map for navigation will require a finer grid than a general atlas map. On
an atlas map the graticule serves to help the reader locate places. On a thematic map,
grid ticks can be used because the reader isn’t trying to determine precise locations. If
grid ticks are used, they must be shown on all sides of the map because this also gives
a sense of the type of projection (Figure 2.23).
