Arial survey

Marine survey

Astronomical survey

Great trigonometrical survey

Land survey

Aerial survey

Marine survey

Astronomical survey

(RF/Length to be measured)

(Length to be measured/RF)

RF x length to be measured

RF x length of scale required

Drawing smaller than object

Drawing smaller, object bigger

Drawing bigger, object smaller

Drawing smaller, object smaller

Plain scale

Vernier scale

Scale of chords

Comparative scales