Spiral slide-rule
1663
Spiral slide rule for complex numbers by Stanley with bakalite handle
1960-1965
Dixon's combined circular and spiral slide rule
Fuller's spiral logarithmic slide rule in mahogany box
Barnard's Co-ordinate spiral slide rule
1909
Barnard's Co-ordinate Calculator
1919
Otis King spiral slide rule
1950-1960
Fuller's spiral slide rule made by W.F.Stanley
1870-1880
Otis King pocket calculator (a spiral logarithmic slide rule)
1920-1925
Otis King pocket calculator
Otis King's patent calculator in case (a spiral logarithmic slide rule)
1923
Fuller's Spiral cylindrical slide rule
1921
Model K
1930-1940
Otis King pocket calculator (a spiral logarithmic slide rule)
Otis King's patent calculator (a spiral logarithmic slide rule)
1923