KEUFFEL & ESSER, New York / USA SN = 421875 (1935) ********************************************************* S C A L E S of the » POLYPHASE DUPLEX « Model 4088-3 ========================================================= Front Side [ inverse / RED ] Back Side ========================================================= K X3 DF πX A X2 --------------------------------------------------------- CF πX B X2 [CIF] [1/πX] S sin(0.1X); sin(0.01X) T tan(0.1X) C X [CI] [1/X] --------------------------------------------------------- D X D X L lgX R E M A R K S : ( 1° = 60' ; 1' = 60" ) ========================================================= The TRIGONOMETRIC SCALES are in MINUTES(') & SECONDS(") S keyed to A/B ; T keyed to C/D This model is made of mahogany with scales on celluloid veneer. It has a cursor with flanges to cover the glass edges. The slide rule came in a brown leather case. Historical Remarks ... One glass was broken and replaced by a home made acrylic. impressum: ********************************************************* © C.HAMANN http://public.BHT-Berlin.de/hamann 06/23/07 |