Re: Ecobra | Joseph Dietzgen | Eugene Dietzgen


Ian Lodge
 

Johann Eichmüller founded a company to manufacture compasses and ruling pens in Nuremberg in 1893. From 1901, Eichmüller began to work exclusively for the American Dietzgen company. US patent 808,644 of 1906 is for a compass mechanism and was granted to Johann Eichmüller, but was assigned to the Eugene Dietzgen Company of New York. The trademark incorporated an image of a windmill, which was also used alone. Eichmüller died in 1908 and his company was taken over by Eugene Dietzgen. The ECOBRA trademark (from Eichmüller and Co, Baeyische Reisszeugfabrik A.G.) was adopted in 1924. The trademark incorporated an image of a windmill, which was also used alone.

 

Slide rule manufacture began after WW2. Early rules were of unpainted aluminium alloy with engraved scales. I have a 25cm and a 12.5cm 1270. From about 1950, an improved alloy was used. This was coated with white enamel, the scales printed on and a coat of clear lacquer applied. Painted metal slide rules were supplied to Dietzgen in the 1950s: the model 1738 is an example. ECOBRA were still making good quality metal slide rules into the 1970s: the 1711 Cosmos is an example. ECOBRA also supplied plastic slide rules, although these were probably sourced from Japan. The ECOBRA 154 is clearly a Hope 530. Hope also supplied Nestler with plastic rules such as the Elemath.

 

Ian

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