A variscale is variable length mechanical scale (ruler) designed to directly measure
latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north ...
and
longitude
Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek let ...
on
USGS
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
maps.
[Roos, M., 1967. Variscale stereo point marking instrument, Photogrammetric Engineering, 33(11):1260-64.]
References
External links
Instructions for using the Variscale
Measuring instruments
Cartography
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