Albert Nestler, Lahr in Baden / Germany                   (1930)
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                                                     VERSION (A)

S C A L E S   of  the    N E S T L E R    » RIETZ «    Model 23R
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Front Side             [ inverse / RED ]               Back Side
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( 0 ...  27 cm Ruler )

K        X3
A        X2
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B        X2                                 S         sin(0.1X)
[CI]     [1/X]                              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(")

There are 2 Versions in the Collection:
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This Vers.(A) has celluloid scales glued with additional screws.
In the body under the slider is a  30 ... 56 cm  ruler.  It has
a table with physical constants on its back side.  The cursor
glass is mounted by 2 metal profiles.  This historic mahogany
slide rule came in a black cardboard case as Model ...

          »  "RIETZ"  No.23RF «   ( ???  "F"  ???)

     

                     ... The "R" refers to the RECIPROCAL SCALE.

Newer Version (B)
Has "glued-only" scales, no inner ruler and a framed cursor.

Historical Remarks ...

This SR was also sold as  GEBR.WICHMANN  Model »1418 R III« ...

impressum:
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© C.HAMANN      http://public.BHT-Berlin.de/hamann      03/30/09