Walther Calculator
"The great depression in 1923 saw a company under great stress for even a box of matches sold for 1 billion marks. In spite of difficulties the Walther Company managed to start again. By 1924 the Company looking towards new products to assist its recovery commenced making calculating machines based on the pin drum mechanism. A method by which depending on a selection lever a number of teeth remained protruding to actuate a pinion located in a movable carriage."

Ray Mackay - The Walther Company - Historic Recollections.

Source: Ray Mackay

X-Number World of Calculators