Ph.J. Maul Duograd letter scale
The enamel scale of this letter scale has the indications Duograd, concav and D.R.G.M. There are indeed two graduations on this scale, hence Duograd. The top scale from zero to fifty grams is subdivided per gram and is used when the counterweight is raised. The lower scale from zero to 250 grams is subdivided per five grams and is used when the counterweight is lowered. The enamel scale is somewhat skewed, this is concav. The designation D.R.G.M. means Deutsches Reich Gebrauchs Muster, a more readily available, cheaper design protection compared to a patent protection. At the top of the black frame is the M logo of the maker Philipp Jakob Maul from Hamburg in Germany. There are also letter scales with Monograd on the scale, see for example this Monograd, or this Aero airmail letter scale. There is also a somewhat older version of the Duograd with a cast iron base, a round letter plateau and a pointer without an extra support arm, see below. The frame of the less old Duograd is made of strip steel. The pointer does have an extra support arm and the letter plateau is rectangular. In the letter plateau the text is NIET VOOR HANDELSDOELEINDEN (= NOT LEGAL FOR TRADE).
Below some more images of this Duograd letter scale.
back of the letter scale
