GEBR. WICHMANN, Berlin / Germany (1925) **************************************************************** S C A L E S of the W I C H M A N N » R I E T Z « ================================================================ Front Side Back Side ================================================================ ( 0 ... 27 cm Ruler ) K X3 A X2 ---------------------------------------------------------------- B X2 S sin(0.01X); sin(0.1X) L lgX C X T tan(0.1X) ---------------------------------------------------------------- D X L lgX ( 0 ... 28 cm Ruler ) R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================ The TRIGONOMETRIC SCALES are divided in MINUTES(') & SECONDS(") S keyed to A/B ; T keyed to C/D The slide rule is made of pear wood with scales on celluloid veneer. On the back side are physical & technical constants. There is no model number given. Under the slider are prints ... » GEBR. WICHMANN, BERLIN « » SYSTEM RIETZ « There is NO MAKER LOGO = ??? = Made by Albert Nestler = ??? = Historical Remarks ... impressum: **************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 04/22/12 |