Abstract
THE Geodetic Report of the Survey of India, vol. 6, deals with the very varied and extensive work done during the period Oct. 1929—Sept. 1930. A regular latitude variation programme has been started, supplementing the regular longitude observations, and in due course will throw light on the existence or otherwise of crustal drift. The irregularities in the longitude results remain unexpectedly large: to improve the time-keeping, a Shortt clock has been obtained. The form of the geoid in India and the gravity work have now brought irrefutable confirmation of Burrard's Hidden Range, which at first was inferred from rather scanty deflexion data; the Hidden Range is found to be flanked on both sides by troughs. Again, the levelling results obtained in Bengal during the last seventy years have been discussed. The closing errors of the various circuits are found to be surprisingly large, much greater than should occur in the class of levelling explained. It appears that they can be simply and naturally explained by supposing that real changes of level have occurred. Parts of the alluvial plains of northern Bengal and Bihar seem to have been rising at the rate of one foot in twenty years; tidal records indicate that Calcutta is not sinking, so that the country farther north is presumed to be rising. Further, tidal predictions for the Indian Ocean have been published in a new and cheap form of greatly increased scope, on lines similar to those of the Admiralty Tide Tables.
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Geodesy in India. Nature 129, 341 (1932). https://doi.org/10.1038/129341b0
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DOI: https://doi.org/10.1038/129341b0