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KEUFFEL & ESSER   681497   ( 10" / 25 cm Scales )



KEUFFEL & ESSER, New York / USA        SN = 540205        (1960)
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S C A L E S   of  the    » POLYPHASE DUPLEX «      Model 681497
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Front Side              [ inverse / RED ]              Back Side
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                              K           X3 
DF        πX                  A           X2 
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CF        πX                  B           X2
[CIF]     [1/πX]              T ; [T]     tan(0.1X); [tan(X)]
[CI]      [1/X]               ST          arc(0.01X)
C         X                   S           sin(0.1X); [cos(0.1X)]
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D         X                   D           X 
L         lgX                 [DI]        [1/X]

R E M A R K S :
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ATTENTION:   Scale [tan(X)] refers to the reciprocal [CI] scale.

This model is made of mahogany  with scales on celluloid veneer.
The print "US" indicates a former property of the US GOVERNMENT.
It came in a brown leather case.

                 Historical Remarks ...
impressum:
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© C.HAMANN  http://public.beuth-hochschule.de/~hamann   07/13/12