previous <<==>> next

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



KEUFFEL & ESSER, New York / USA        SN = 540205        (1960)
****************************************************************

S C A L E S   of  the    » POLYPHASE DUPLEX «      Model 681497
================================================================
Front Side              [ inverse / RED ]              Back Side
================================================================

                              K           X3 
DF        πX                  A           X2 
----------------------------------------------------------------
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)]
----------------------------------------------------------------
D         X                   D           X 
L         lgX                 [DI]        [1/X]

R E M A R K S :
================================================================
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:
****************************************************************
© C.HAMANN     http://public.BHT-Berlin.de/hamann       07/13/12