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Ordnance Survey's Levelling of Great Britain |
[1GL, 2GL Abstract] [1GL, 2GL Transcription] |
[Timeline] [FBM List] |
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[assume Great Britain unless specifed] |
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First primary levelling (+) |
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Second geodetic levelling - England & Wales (+) |
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(World War One) |
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Measurement of the Ordnance Datum Newlyn |
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Relevelling of Greater London |
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Second geodetic levelling - Scotland |
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(2nd World War) |
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Second geodetic levelling - East Anglia and Kent |
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Third geodetic levelling - England & Wales |
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Third geodetic levelling - Scotland |
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Cyclic relevelling - England & Wales |
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Cyclic relevelling - Scotland |
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GPS era |
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[assume Great Britain unless specifed] |
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Sources used on this page
Ordnance Survay Maps a descriptive manual - J B Harley
[www.osni.gov.uk]