Description and Notes:
This is an original Lotter drawing set which bears the article number 202 a.b.TV. It contains the ingenuously designed and highly sought after precision parallel compass. Unlike simpler handle self-centering mechanism of gear pair and ball-bearing types, each of the two legs of the compass is constructed as a four-bar parallelogram kinematic chain similar to that of a floating arm desk lamp, which consists of the handle, the upper and the lower part of the leg, and a coupler link to close the loop; so that when the compass is opened, not only the handle is always centered, but the lower part of the two legs would also be parallel to the handle and to each other regardless the opening angle. It should, however, be noted that the design is in fact not original, as it is similar to that of the Halden vertical drawing compass devised earlier.
The detailed official history and chronicles of the company is yet to be found. Nevertheless the following information was provided by a member of the Drawing Instruments Group of Yahoo:
"'Lotter' was founded in 1896 in Wilhelmsdorf, Germany and was sold to Boden in 1980. It is also possible that as founding year 1892 has to be claimed, dependent on the way Lotter and Boden parted in 1896. Since Boden was (and is) situated in Emskirchen, a few kilometers from Wilhelmsdorf, it is feasible that Boden just parted with the mutual company in Wilhelmsdorf and started his own factory in Emskirchen."
According to another member of the group, who bought the first set as a trainee (From a Dutch Engineering school) in Solingen, Germany in 1955, the production of the parallel set should be started no later than 1952.