Gorgeous Concav postal letter scale by Ph. J. Maul. It is a robust weighing scale made out of cast iron and brass, the concave-shaped reading chart is made of enamel. The range of the letter scale shown, is 0-500 grams.
The Concav scale has two reading charts. The upper one is up to 100 grams. To use the upper chart, the weight needs to be put in the upper position. The lower chart reaches up to 500 grams and to use the lower chart, the weight needs to be put in the lower position.
On the lower chart there is a gradation stripe per gram, on the upper chart there is a gradation stripe per 5 grams.
Manufactured by Jacob Maul in Germany, 1910's