(:title ~1910: Seidel & Naumann (SUN) Adding Machine:)


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This calculator was manufactured in Germany and is based upon a chain mechanism with a slider for each integer column, the sliders being pulled by means of a stylus.  Tens carry automatically. The result register can be cleared by means of the crank lever on the side, top right.  Subtraction is achieved by addition of the complementary numbers.

The A lever sets the machine for addition by erasing the last result whilst the M setting locks the current number in place so that it can be added to itself.

There were three models produced of which this is the smaller (9 column) version.  A sliding vertical bar which allows the columns of the result register to be lined up with the corresponding chain on the input panel appears to have gone missing.