Albert Nestler, Lahr in Baden / Germany (1950)
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S C A L E S of the N E S T L E R »PRAEZISION« Model 0270
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Front Side [ inverse / RED ] Back Side
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( 0 ... 27 cm Ruler )
L lg( W1 = sqrt(X) ) ; lg( W2 = sqrt(10X) )
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D X
W1 sqrt(X)
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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'
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W2 sqrt(10X)
SIN 2° .. 5° 40' ==read==>> W2
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K1 W13
K2 W23
R E M A R K S : ( 1° = 60' ; 1' = 60" )
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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:
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© C.HAMANN http://public.BHT-Berlin.de/hamann 09/19/12
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