WMF
letter scale
No. 525

Again a letter scale from the Württembergische Metallwarenfabrik from Gieslingen/Steige in Germany. The scale base is marked at the bottom. In the middle is the number 525. In a catalog from 1914 this can be found as model number 525. On one side is the marking OX, then a logo of WMF and then the marking I/O. OX means that the silver surface has been artificially darkened. The WMF logo with the beehive which at the top is not horizontally embossed and has a rhombus in which an ostrich and the capitals WMF G, dates from the period 1910-1925. The marking I/O indicates that 1 gram of silver is applied per square decimeter. Another source says that the normal amount of silver is applied per unit area, which is rather vague. The letter α (alpha) is in the inside edge. I don't know the meaning of this. At the bottom of the back of the letter scale stand, once again is the logo of WMF with the ostrich in a rhombus on a beehive.
The scale of this letter scale has Gr. as the unit of measure. The scale up to 50 grams has a stripe of measure per five grams. Only between 10 and 20 grams there is a stripe per each gram. A special feature of this model is the hinge at the bottom of the stand. The weighing mechanism can thus be set to zero. According to a page in the 1914 WMF catalog this idea was protected by a D.R.G.M. patent. Until now, I didn't find it.
There are many more letter scale models from WMF, see for example WMF letter scale, the WMF No.117 and also this WMF letter scale. They mainly differ in the execution of the scale basis. Some models have a stamp box, other models an ink set, other more extensive models an ink set, an envelope holder, ink blotter, pen holder, stamp box and a thermometer.
Below some more images of this old WMF letter scale.