Albert Nestler, Lahr in Baden / Germany                   (1920)
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S C A L E S   of  the   N E S T L E R    » RIETZ «    Model 20/3
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Front Side                                             Back Side
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( 0 ...  27 cm Ruler )

K        X3
A        X2
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B        X2                                 S         sin(0.1X)
                                            ST        arc(0.01X)
C        X                                  T         tan(0.1X)
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D        X
L        lgX

( 1:25 Ruler )

R E M A R K S :                       (  1° = 60' ;   1' = 60" )
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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:
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© C.HAMANN     http://public.BHT-Berlin.de/hamann       04/03/07