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KEUFFEL & ESSER   4080-3   ( 10" / 25 cm Scales )



KEUFFEL & ESSER, Hoboken, NewJersey / USA      SN = 224842        (1930)
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S C A L E S   of  the    » LOG LOG DUPLEX TRIG «            Model 4080-3
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Front Side                   [ inverse / RED ]                 Back Side
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L      lgX           [LL0]   [exp(-0.001X) .. exp(-0.01X) .. exp(-0.1X)]
LL1    exp(0.01X)    [LL00]  [exp(-0.1X) .. exp(-1X) .. exp(-10X)]
DF     πX            A       X2 
------------------------------------------------------------------------
CF     πX            B       X2
[CIF]  [1/πX]        T       tan(0.1X) ; [cot(0.1X)]
[CI]   [1/X]         ST      arc(0.01X)
C      X             S       sin(0.1X) ; [cos(0.1X)]
------------------------------------------------------------------------
D      X             D       X 
LL3    exp(X)        [DI]    [1/X]
LL2    exp(0.1X)     K       X3

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

The scales [LL0] & [LL00] are keyed to scale A.

This model is made of mahogany with scales on celluloid veneer.
The sturdy cardboard case is covered with black artificial leather
but the lid is made of genuin leather.

                     Historical Remarks ...
impressum:
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© C.HAMANN      http://public.beuth-hochschule.de/~hamann       05/17/09