letter scale

This letter scale was manufactured in Czechoslovakia, this country name is pressed into the bottom. The top plate of the scale is advertising six products of the French firm Dr. Bengué & Fils, pharmaciens, from Paris. The advertising imprint is graphically beautiful. The letter scale is selfadjusting to zero because the pointer arm is suspended rotatable. The scale range is 100 grams. In the first 20 grams every gram has a stripe of measure. Above 20 grams there is a stripe per five grams. Dr. Jules Bengué lived from 1840 to 1898. He has several patents to his name. The company stopped in 1976. From when this letter scale dates is unknown to me.
The design was made by the firm Balduin Heller's Söhne, Teplitz-Schönau in Czechoslovakia. It was protected in April 1935 by a German patent DE1334238. The top plate of this letter scale is even more consistent with the design shown in the patent.
Below som more pictures of this letter scale.