Hyperbolic Match Output
Maker:KEUFFEL & ESSER (USA)
Model:Log Log Duplex Vector No. 4083-3
Scales Front: || L, LL1, DF || CF, CIF, CI, C || D, LL3, LL2||
Scales Back: || LL0, LL00, A || B, T&T, ST, S&S || D, Th, Sh2, Sh1|| See C.M. - K&E Catalogs site.
Gauge Marks: π is on A, B, CF, and DF; π/4 is on A and B scales; The marks 1°, ' and " are on scale ST.
Construction: 10 in.; Plastic face on wood ; Cursor is framed. Adjustable metal brackets.
Date: 1939 - 1947
Source: Clark McCoy's Collection
Information: (See C.M. - K&E Catalogs site).