ACCORDING to the Archive Antiques store owner, last week’s mystery item is an Ottis King slide rule used for multiplication and division. It was made in England and was popular in the days before digital calculators.
Three dozen readers wrote in with that same answer, which was a great turnout for week one. The fastest of them were: Maxine Burger, Tony Horsham, Stuart Hadrill, Charles Spiegel, Michelle Cooke, Robin Gilmour, Stephen Penneyston, Cedric Lockley and Brian Young. Arthur Sale PhD wrote to say it actually was not a spiral slide rule but rather a helical slide rule.