The Second GEODETIC LEVELLING of ENGLAND & WALES 1912-1921 Published, by Order of the Ministry of Agriculture and Fisheries, by Colonel Sir Charles Close, KBE, CB, CMG, FRS Director-General of the Ordnance Survey, Southampton 1921 |
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[Companion volume to the '2GL Abstract' - Original Index] |
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Contents * | |||
Introduction | 4 | ||
I | (AJW) | History of the Ordnance Survey Levelling | 7 |
II | (AJW) | Instruments | 11 |
III | (AJW) | Methods of Observation | 15 |
IV | (HLPJ) | Orthometric and Dynamic Corrections | 19 |
V | (AJW) | Tidal Observations | 24 |
VI | (HLPJ) | Mean Sea Level | 30 |
VII | (HLPJ) | Effect of Meteorological Conditions on the level of the sea | 35 |
VIII | (HLPJ) | The errors of levelling and the method of reduction | 39 |
VIX | (HLPJ) | Reduction of the observations of the level net | 55 |
PLATES (gallery) |
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I | Diagram of network of 1st Geodetic Levelling. | ||
II | Diagram of network of 2nd Geodetic Levelling. | ||
III | Diagram of difference of level of old and new levelling | ||
IV | Diagram of Tidal Gauges, Liverpool | ||
V | Zeiss Level | ||
VI | Zeiss Level | ||
VII | Geodetic Staves | ||
VIII | Details of Geodetic Staves | ||
IX | Graduation of Geodetic Staves | ||
X | Fundamental Bench Mark | ||
XI | Flush Bracket | ||
XII | Dunbar Tidal Observatory | ||
XIIa | Newlyn Tidal Observatory | ||
XIII | Automatic Tide Gauge | ||
XIV to XX | Sea Level Curves [not scanned ...] | ||
XXI to XLII | Error Curves [not scanned ...] | ||
XLIII to XLVI | Reduction Equations [not scanned ...] | ||
* The initials are those of the writers of the respective chapters: AJW standing for Lieut.-Colonel A.J. Wolff, DSO, RE, and HLPJ for Mr H.L.P. Jolly, MA |