Calibration table for the Marinoni position micrometer by J. Scherer

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Object notes Associations
On the last page of volume IV of the Records of the Specola di Bologna, dated May 1734, there is a calibration table for the micrometer written by Eustachio Manfredi (1674-1739), who was the first astronomer of the Bologna Observatory. It gives the relation between a turn of the micrometric screw and the angle measurement.