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Horizontal
Section 1 Method Accuracy Remarks Equipment 2
angle

Best for 40-
Home-made 80 m.
Medium to
3.1* graphomete Low For angles Graphometer
large
r greater than
10°.

Best for 40-
100 m.
For angles
Magnetic Medium to greater than
3.2** Medium Compass
compass large 10°.

No magne
tic distur-
bance.

Simple
Dry
Compass or Low to compass,
3.3* All sizes weather
protractor medium protractor,
only.
drawing sheet
Dry
Low to Plane-table,
3.3** Plane-table All sizes weather
medium drawing paper
only.

Perpendicul
Right-angle Medium to Measuring
3.4* Small ar to be set
method high line
out

Transit level
Useful on
Theodolite with gradua-
3.5*** All sizes High long
or transit ted horizon-
distances
tal circle

Adapt
method to
Miscella- Right-angle Medium to
3.6 length of Various
neous Only high
perpendi
cular
1
*Simple **More difficult ***Most difficult

A theodolite, sometimes called a transit, is an expensive
instrument which surveyors use to measure horizontal angles

precisely. Most theodolites are designed to measure vertical angles as

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