Charles Bruning Co.  /  USA                              (1960)
***************************************************************

SCALES   of  the   B R U N I N G    » MANNHEIM «     Model 2420
===============================================================
Front Side            [ inverse / RED ]               Back Side
===============================================================

( 0 ...  10" Ruler )
---------------------------------------------------------------
A       X2
---------------------------------------------------------------
B       X2                        S       sin(0.1X); sin(0.01X)
[CI]    [1/X]                     L       lgX
C       X                         T       tan(0.1X)
---------------------------------------------------------------
D       X
K       X3
---------------------------------------------------------------
( 0 ...  25 cm Ruler )

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

S keyed to A/B ;  T keyed to C/D

This SR is made of white plastic. Its back side has  screws  to
allow adjustment  of the sliding friction.  It came in a  black
cardboard case w. leather flap  and w. the BRUNING-Logo and the
Model-Number »2420« on it.

Body and Scales of this SR are the same as  POST »1452P« - BUT:
It has NO conversion tables on its back side and it has another
cursor.  Its GLASS was broken.  Replacement is made of PVC from
a CD-Case:  The Hairline is made with an  »X-ACTO«  and colored
with a red Permanent-Marker.

                     Historical Remarks ...
impressum:
***************************************************************
© C.HAMANN     http://public.BHT-Berlin.de/hamann      07/20/13