Albert Nestler, Lahr in Baden / Germany (1920) **************************************************************** S C A L E S of the N E S T L E R » RIETZ « Model 20/3 ================================================================ Front Side Back Side ================================================================ ( 0 ... 27 cm Ruler ) K X3 A X2 ---------------------------------------------------------------- B X2 S sin(0.1X) ST arc(0.01X) C X T tan(0.1X) ---------------------------------------------------------------- D X L lgX ( 1:25 Ruler ) R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================ The TRIGONOMETRIC SCALES are divided in MINUTES(') & SECONDS(") This historic wooden » Model 20 « has NO reciprocal scale. On its back side is a table with physical constants. It came in a black cardboard case: The "/3" on the CASE refers to 3 HAIRLINES on the cursor. Historical Remarks ... impressum: **************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 04/03/07 |