This is a small French Hewlett disc in green glazed porcelain. The diameter is just under 4 inch. In the unglazed center it is marked with abbreviations in French: "B té"; Bréveté (patented), "SGDG"; Sans Garantie Du Gouvernement (without governmental guarantee). This Hewlett were taken down from a small loco shed on a old mining railway in the French alps.

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