Historical information

These transparent sheets were used to measure area on maps at various scales.
They were used if a planimeter wasn't available
The sheet was overlayed on the map and the shape transferred with a soft China graph or erasable lead pencil
The number of "dots" within the shape were counted and converted to an area
Each major 1 inch square block contained 100 dots (10 x 10)

Physical description

Transparent dot grid sheet

Inscriptions & markings

Forests Commission of Victoria
Area Scale
Scale 30 chains to the inch