International Institution for
the History of Surveying and Measurement
A Permanent Institution within the International
Federation of Surveyors (FIG)
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Baselines
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From 7th Report Adirondack Survey. 1880. Courtesy
W. G. Robillard. |
A baseline is a particular line on the
ground, usually several miles (km) long, that has been measured with the
utmost accuracy with the equipment available at the time. A list of these
together with some of the features of each is being compiled by J R Smith,
but with at least several hundred such lines there is some way to go.
Such lines are generally related to the use of triangulation. Over the last
350 years a wide variety of equipment has been used for such measures
ranging from wooden bars to glass rods, long wires and electromagnetic
methods.
Every triangulation scheme requires at
least one baseline to introduce scale into the results.
Examples:
Hounslow Heath 1785
See A History of the Ordnance
Survey. Ed. W A Seymour. 1980. Dawson. ISBN 0-7129-0979-6
Calcutta 1832 Historical
Records of the Survey of India. Vol. IV 1830-1843. R H Phillimore. 1958.
Lough Foyle 1828 An
Account of the Measurement of the Lough Foyle Base in Ireland with its
verification and extension by triangulation.W Yolland. 1847.
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