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NESTLER » PRAEZISION «
( 25 cm with 50 cm Scales W1/W1' & W2/W2' )
Albert Nestler, Lahr in Baden / Germany (1912)
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S C A L E S of the N E S T L E R »PRAEZISION« Model 27
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Front Side Back Side
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( 0 ... 25 cm Ruler )
D X
W1 sqrt(X)
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W1' sqrt(X) SIN 6° .. 18° ===read===>> W1'
L1 lg( W1 = sqrt(X) ) SIN 19° .. 80° ===read===>> W2'
L2 lg( W2 = sqrt(10X) ) TAN 6° .. 17° ===read===>> W1'
W2' sqrt(10X) TAN 18° .. 45° ===read===>> W2'
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W2 sqrt(10X)
D' 10X
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SIN 2° .. 5° ==read==>> W2 ( Right Mark of Cursor Ext. )
K X3 ( Left Mark of Cursor Extention )
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 wooden model came in a black cardboard case.
It has a table with physical constants on its back side.
In the body under the slider is a 31 ... 53 cm ruler.
Historical Remarks ...
The slide rule came in bad shape: The slider was locked, scales
were dirty & scratched, partly broken, partly not glued. The
cursor was from NESTLER, but not the original one: It had to be
modified with an EXTENSION to use the scales from the side too.
"MouseOver" the Cursor to get DETAILED VIEWS ...
Compare the SCALE DESIGN with
the »NESTLER-0270«,
the »WICHMANN-1417« ( made by A.N. = Albert Nestler),
the POST-1442 » Dual 10"/5" POCKET-SR «,
the FABER-CASTELL »COLUMBUS/A.Rohrberg« and
the "modern" FABER-CASTELL »NOVO-DUPLEX«
P.S.: In 2008 the ORIG.CURSOR was found:
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