5
THE CLINOMETER
T
he SILVA Ranger compasses are practical instruments for measuring angles of
inclination. The long side of the compass coincides with the slope of the terrain.
Measure an angle of inclination in the following way:
1. Open the lid completely.
2. Turn the dial so that the cardinal point “W” on the dial is set at the index pointer.
3. Hold he compass at eye level with arms out-stretched so that the clinometer
needle is hanging vertically and follows the scale in the bottom of the compass
housing. “S” on the compass should point down.
4. Let one long side of the compass coincide with the slope of the terrain— the
inclination you wish to measure.
5. Read the angle of inclination at the point of the clinometer needle.
RULES OF USE
T
wo separate sets of rules apply to the use of a magnetic compass. One set applies
if you work “from map to terrain.” In this case you take “map bearings.” In the fol-
lowing, Sections A, B, C, D and E deal with “from map to terrain.”
E
xactly opposite rules apply if you work “from terrain to map.” In this case you use
“field bearings,” also called “magnetic bearings” and “compass bearings,” Sections F,
G and H deal with “from terrain to map.”
T
he word “map” is broadly interpreted to also include charts, descriptions and even
a mental picture of the terrain.
