A topographic map lets us describe where a feature is and in which direction it lies. Two skills are tested: giving direction and giving position.
Direction and bearing
The compass has 8 main points: north, north-east, east, south-east, south, south-west, west and north-west. A more exact method is the bearing, an angle measured clockwise from north and always written with three digits from 000° to 360°. For example, due east is a bearing of 090° and due south is 180°.
Key idea
Direction is always read from one place to another. The direction of X from Y is found by standing at Y and facing X. On a map, north is at the top (grid north).
Grid references
Blue grid lines form squares. Vertical lines are eastings (numbered left to right) and horizontal lines are northings (numbered bottom to top). A four-figure grid reference names one whole square, giving the easting first, then the northing. A six-figure grid reference is more precise: each square is imagined as divided into tenths, so the position is fixed to a point inside the square. Because the numbering never repeats on one map, every six-figure reference points to just one place, which is why examiners use it to name features exactly.
Example
To read a six-figure reference, go along the corridor (eastings) first, then up the stairs (northings): read 46, estimate 5 tenths across, then 23, estimate 8 tenths up, giving 465238.
Remember
- Eastings before northings, every time.
- Bearings are measured clockwise from north, 000°-360°.
- A four-figure reference locates a square; six figures locate a point.