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