Map and Compass

1. What they did

This is a short handbook from 1964, number 7 in The Boy Scout Series, published by the National Council of the Boy Scouts of Canada to teach Scouts map reading and compass use. It is a teaching manual, not a research study. In short sections it explains:

• Maps. What a map is, why topographic maps serve Scouts best (the 1:50,000 and 1:125,000 scales are recommended), map symbols, and contour lines.
• Using a map. Setting (orienting) a map, reading its scales, and giving six-figure grid references.
• The compass. A short history, how the needle works, the parts of the orienteering compass, and magnetic north versus true north (declination).
• Using the compass. Following a bearing, taking a bearing, returning to the start, and using map and compass together.
• Practice. Orienteering events, orienteering games, making a map with a home-made plane table, and making a “romer” for precise map references.

Quizzes on map symbols and on map references, with answers at the end, use sample topographic maps.

2. What they found

As a teaching manual, the booklet gives instructions rather than findings. Its main points:

Maps

• On topographic maps, black shows the work of people (roads, railways, towns, bridges, boundaries and names), blue shows water, and brown shows hills and valleys. Some maps also show woodland in green and main highways in red.
• Every point on a contour line is at the same height above sea level, usually 25 feet from the next line. Lines far apart mean gentle slopes (suitable for a campsite); lines close together mean steep ground; lines that come together mean a cliff.
• A map can be set by compass, by known landmarks, by watch and sun (described as very rough), or by the stars, using the Pole Star (Polaris).
• Six-figure map references give the easting (the vertical grid line) first and then the northing (the horizontal grid line), each with a third figure estimated in tenths of a grid square.

The compass

• The needle points to magnetic north, not true north. The booklet places the magnetic north pole about 1,400 miles south of the geographic North Pole, near the west coast of the Boothia Peninsula.
• Declination depends on where you are. Near a line through Port Arthur, Fort William, Nelson and Churchill, compass north is close to true north. At the time of writing, the compass pointed 15° west of true north in Ottawa and 24° east in Vancouver. The rule given is to add westerly declination and subtract easterly declination.
• The needle is a small magnet, so the compass should be kept away from knives, bicycles, wire fences and even zip fasteners.
• Directions are best given in degrees (magnetic azimuth) rather than by the cardinal points, because degrees are more accurate.
• To follow a bearing: set the bearing on the compass housing, turn your whole body until the needle lies over the north marking, then sight a landmark straight ahead and walk to it. To return to the start, hold the compass with the direction arrow pointing back towards you and do the same.
• Map and compass are used together in three steps: lay the base plate along the route, turn the housing to line up with the map’s north-south lines, then turn your body until the needle lies over the north arrow. An extra step adjusts for declination.

Practice

• Four kinds of orienteering event are described: route orienteering (marking stations found along a set route), project orienteering (with Scoutcraft tasks at each station), point orienteering (choosing your own route between points in order), and score orienteering (choosing which stations to visit for the best score within a time limit).
• Games include the “silver dollar” game (three legs of 100 feet, adding 120° each time, to see how close you return to a marker), a miniature compass walk, compass walks along a line of fence posts using back bearings, and a compass competition in which each participant first measures the length of their step over 200 feet.
• Map-making with a plane table and a sight ruler rests on “three D’s”: direction, distances and detail. Distances are paced (one inch to 40 strides is suggested as a scale), and each station is checked by back-sighting and the compass.

3. What they concluded

• Learning to read degrees rather than cardinal points, and allowing for declination, makes compass work more accurate.
• Once Scouts are proficient with map and compass, they can test their skills against other patrols in orienteering events, organised by their district or council, or arranged with another Scout troop.
• A finished map is of little use without place names, a north indication and a scale; the mapmaker should also add their name, patrol, troop and the date.

6. Other technologies, skills or innovations

• The orienteering compass: a needle in a rotating housing on a transparent base plate, with a direction-of-travel arrow, an orienting arrow, an inch scale for Canadian maps and a millimetre scale for some foreign maps.
• Home-made equipment: a plane table (a board about 12 by 14 inches on three legs about 4 feet long, with a compass fixed on top), a sight ruler made from a ruler and two finishing nails, and a cardboard romer for reading map references precisely.
• Pacing to measure distance on the ground.