Slide Rule with Addiator

"As opposed to slide rules which were analog devices, slide adders were discrete devices. However, because of its sliding nature, slide adders were more related to slide rules than to mechanical calculators. Faber-Castell, a well known slide rule manufacturer, bought Addiator and incorporated its device in the back of their slide rules."

James Redin

Photo Source: Timo Leipala

X-Number World