letter scale

This is one of the many letter scale models by Narcisse Briais from Paris in France. The weighing range is 60 grams and the scale is subdivided per 5 grams. The letter scale is completely brass. The base is molded. On the front of scale frame is engraved N x B that is the logo of Narcisse Briais. Below this is the text B^TE = Breveté (patented) and SGDG = Sans Garantie Du Gouvernement (without government guarantee, so not calibrated). Narcisse Briais was a French instrument maker who crafted letter scales and balances between 1859 and 1886. The N.B. logo was introduced in 1876. After 1886 G. Restorf took over the company and continued to apply the N.B. logo. In 1914 Restorf discontinued the company. After this M. Ducos used the logo N.B. on his letter scales in the period 1915-1926 and from 1927-1931 M. Guérin continued to apply the N.B. logo still on letter scales (source: Le Système métrique 1997-3, page 1124). This complicates a precise date, it can be at its largest between 1876 and 1931. This brass letter scale is already presented on a poster of Briais from April 1893. From Narcisse Briais, or from his successors, letter scales have been shown already, see the photographic scale, the Loth letter scale, de herbs & powder scale, the déposé letter scale, and this balance.
Below some more pictures of this old letter scale.