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Astro Addiator
This stylus-operated Addiator is designed for addition and subtraction of angles in degrees-minutes-seconds or time in hours-minutes-seconds, where the number system uses sexagesimal units (i.e. based on 60). Note the maximum value '5' in two of the columns.
The machine is double-sided, with one side for addition and the other side for subtraction. In the photographs it is displaying the angle 123 45' 12.34" or the time 123hrs 45min 12.34sec.
84 x 128 x 6 mm (3.3" x 5.0" x 0.25").
This version manufactured about 1938 - 1957.
It is called 'Astro' since it would have been useful to Astronomers.