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The tool was DEFINITELY NOT invented by Henry Bouchard. See Denis Diderot, Jean D'Alembert: L'encyclopédie de Diderot et d'Alembert, ou dictionnaire raisonné des sciences, des arts et des métiers. Paris, 1751-80. On Plate XIII ""Outils de Marbrerie"", you find fig. 12 and 14, with dicription ""boucharde"".

Best regards, PUNG. See also German Wiki."