Dictionary of precision Instrument-makers and related craftsmen

A. G.               Approvisionnement Général de la Marine

Crowned ‘C’    A stamp applied to objects made of copper alloys to indicate that tax had been paid on the object so marked. This tax on copper alloys was introduced by royal edict in February 1745 and abolished 4 February 1749, being one of several ‘minor new taxes’ introduced to help finance the War of the Austrian Succession, ended by the treaty of Aix-La-Chapelle, February 1749. The punch mark was to be applied, on payment of the appropriate fee, ‘to all work, old or new, in bronze, pure copper, cast, mixed copper, forged, moulded, hammered, planed, engraved, gilt, silvered or “put in colour”, without any exception’. The inclusion of ‘old work’ means that the mark may be found on items predating the period of application if they were regilt or resold during these four years. [1]

SGDG             Sans garanti du Gouvernement (disclaimer added to instruments protected by a patent

S. H.                Service Hydrographique [de la marine]