ABSTRACT
The convenience of pendulum observations seemed to entail a disposition to think in terms of simplified Earth-models even as the developing subject of geology showed just how complex the Earth's interior was likely to be. If there is an ultimate ironic twist to the Figure of the Earth story it is surely the vast and largely secret effort that went into the three-dimensional mapping of the northern hemisphere during the Cold War. With extraordinary accuracies available, the whole emphasis of gravity surveys has shifted away from surface topography to the search for gravity anomalies as indicators of underground features and mineral deposits. From Richer's equatorial measurements almost until the electronic age, the pendulum remained the sole instrument for the measurement of gravity to tolerable accuracy in the field. The Paris Academie ran a special conference with expert reviews of all aspects of the surveys and the modern subject’ and there were appropriate ceremonies in Ecuador.
