Albert Nestler, Lahr in Baden / Germany (1950) ***************************************************************** S C A L E S of the N E S T L E R »PRAEZISION« Model 0270 ================================================================= Front Side [ inverse / RED ] Back Side ================================================================= ( 0 ... 27 cm Ruler ) L lg( W1 = sqrt(X) ) ; lg( W2 = sqrt(10X) ) ----------------------------------------------------------------- D X W1 sqrt(X) ----------------------------------------------------------------- W1' sqrt(X) SIN 6° .. 18° ===read===>> W1' [W2'] [ sqrt(10X) ] SIN 19° .. 80° ===read===>> W2' [W1'] [ sqrt(X) ] TAN 6° .. 17° ===read===>> W1' W2' sqrt(10X) TAN 18° .. 45° ===read===>> W2' ----------------------------------------------------------------- W2 sqrt(10X) SIN 2° .. 5° 40' ==read==>> W2 ----------------------------------------------------------------- K1 W13 K2 W23 R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================= The TRIGONOMETRIC SCALES are divided in MINUTES(') & SECONDS(") Because the scales W1/W1' start at 1 and end at sqrt(10) and the scales W2/W2' start at sqrt(10) and end at 10 the 25 cm NESTLER has the "PRECISION" of a 50 cm slide rule !!! This historic mahogany model has a table with physical constants on its back side and a blind print "28" ? It came without case. Historical Remarks ... Compare the SCALE DESIGN with the »NESTLER-27«, the »WICHMANN-1417« ( made by A.N. = Albert Nestler), the FABER-CASTELL »COLUMBUS/A.Rohrberg« and the "modern" FABER-CASTELL »NOVO-DUPLEX« impressum: ***************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 09/19/12 |