KEUFFEL & ESSER, New York / USA SN = 130526 (1950) ***************************************************************** VERSION (B) S C A L E S of the » P O C K E T « Model 4097_D ================================================================= Front Side [ inverse / RED ] Back Side ================================================================= ( 0 ... 5" Ruler ) A X2 DF πX ----------------------------------------------------------------- CF πX S sin(0.01X); sin(0.1X) B X2 [CI] [1/X] L lgX C X T tan(0.1X) ----------------------------------------------------------------- D X K X3 ( 0 ... 13 cm Ruler ) R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================= The TRIGONOMETRIC SCALES are divided in MINUTES & SECONDS S keyed to B ( on BACK SIDE !); T keyed to C/D This Celluloid Pocket-SR was found in a Flea-Market with a broken Cursor-Window. Replacement is made of PVC from a CD-Case: The Hairline is made with an »X-ACTO« and colored with a black Permanent-Marker. There is an OLDER VERSION (A) in the Collection -------------------------------------------------- with an O L D E R L O G O and SN = 52934 ... Historical Remarks ... impressum: ***************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 10/11/12 |