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KEUFFEL & ESSER   4092-3   ( 10" / 25 cm Scales )
WITH A CONFUSING  LL0  SCALE  (*)






KEUFFEL & ESSER, Hoboken, NewJersey / USA    SN = 103686   (1930)
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S C A L E S   of  the     » LOG LOG DUPLEX «         Model 4092-3
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Front Side             [ inverse / RED ]                Back Side
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K        X3                       LL0   exp(-0.1X) // exp(-0.01X)
DF       πX                       A     X2
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CF       πX                       B     X2
[CIF]    [1/πX]                   S     sin(0.1X); sin(0.01X)
[CI]     [1/X]                    T     tan(0.1X)
C        X                        C     X
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D        X                        LL3   exp(X)
L        lgX                      LL2   exp(0.1X)
                                  LL1   exp(0.01X)

R E M A R K S :                        (  1° = 60' ;   1' = 60" )
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The TRIGONOMETRIC SCALES  are devided in  MINUTES(') & SECONDS(")

S keyed to B ;  T keyed to C ;
LL0 is keyed to A Scale (!!!) ;    LL1, LL2 & LL3 are keyed to  D

This SR is made of mahogany with scales on celluloid veneer.  The
brown leather case has the inscription  » LOGLOG DUPLEX/4092-3S «
One glass was broken and replaced by a home made acrylic.

A 2nd Version with  F R A M E D  CURSOR  is in the Collection ...
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                                                      SN = 321846


(*)  R E M A R K :                              !!! CONFUSING !!!
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Observe LL0-Scale is keyed to A-Scale ...
exp(-0.2)=0.82; exp(-0.7)=0.5; exp(-2)=0.135 (=!!!=)
                               exp(-0.04)=0.960; exp(-0.07)=0.932

Compare MODEL 4080-3 (!) Here in Model 4092-3 are 2 SCALES MIXED:

LEFT PART OF [LL00] = .90  ..  .05
                               RIGHT PART OF [LL0] = .97  ..  .91

                     Historical Remarks ...
impressum:
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© C.HAMANN   http://public.beuth-hochschule.de/~hamann   11/21/14