KEUFFEL & ESSER, Hoboken, NewJersey / USA SN = 103686 (1930) ***************************************************************** S C A L E S of the » LOG LOG DUPLEX « Model 4092-3 ================================================================= Front Side [ inverse / RED ] Back Side ================================================================= K X3 LL0 exp(-0.1X) // exp(-0.01X) DF πX A X2 ----------------------------------------------------------------- CF πX B X2 [CIF] [1/πX] S sin(0.1X); sin(0.01X) [CI] [1/X] T tan(0.1X) C X C X ----------------------------------------------------------------- D X LL3 exp(X) L lgX LL2 exp(0.1X) LL1 exp(0.01X) R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================= The TRIGONOMETRIC SCALES are devided in MINUTES(') & SECONDS(") S keyed to B ; T keyed to C ; LL0 is keyed to A Scale (!!!) ; LL1, LL2 & LL3 are keyed to D This SR is made of mahogany with scales on celluloid veneer. The brown leather case has the inscription » LOGLOG DUPLEX/4092-3S « One glass was broken and replaced by a home made acrylic. A 2nd Version with F R A M E D CURSOR is in the Collection ... ----------------------------------------------------------------- SN = 321846 (*) R E M A R K : !!! CONFUSING !!! ***************************************************************** Observe LL0-Scale is keyed to A-Scale ... exp(-0.2)=0.82; exp(-0.7)=0.5; exp(-2)=0.135 (=!!!=) exp(-0.04)=0.960; exp(-0.07)=0.932 Compare MODEL 4080-3 (!) Here in Model 4092-3 are 2 SCALES MIXED: LEFT PART OF [LL00] = .90 .. .05 RIGHT PART OF [LL0] = .97 .. .91 Historical Remarks ... impressum: ***************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 11/21/14 |