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Abstract

Obtaining continuous record of Earth variables, now a standard, has been a problem for centuries. First attempts for graphical continuous records started in the XVIII Century; but those early attempts did not generalize. It was necessary to wait until the second half of the XIX Century for their generalization.The continuous record was hampered by technical problems. Continuous analogue records were obtained on paper support (smoked, ink photographical, etc.) and a main issue was to get enough power for the mechanism moving the paper sheets. A second problem was to get a stable speed for the records. All these problems were not really overcome until the second half of the XX Century, when electrical power generalized all over the world and allowed powerful and precise mechanism to sustain properly the advancement of the recording sheets.Other problems were the limited amplitude and resolution posed by the sheet’s dimensions and the paper speed, as well as the frequency band wide required. These problems forced original and specific solutions for each case. In fact, graphical continuous recording was a continuous trade between the desired record and the technical available solutions,This presentation reviews the evolution of the analogue continuous record in several fields of geophysics (meteorology, seismology, oceanography, geomagnetism) pointing some insights allowing a better interpretation of the recorded series.