Details and Image
Area of Use
Circular and Spiral Slide Rules
Barron / Chandler?s Adding and Subtracting Scale
Ø 8.2 cm
Adding and Subtracting
"Slide chart with copyrighted design by E. F. Chandler for doing addition and subtraction with either: (i) fractions, (ii) in 1/64th increments, (iii) their decimal equivalents or (iv) mixed calculations."