previous <<==>> next
KEUFFEL & ESSER POCKET 4097_D
( 5" / 12.5 cm Scales )
KEUFFEL & ESSER, New York / USA SN = 130526 (1950)
*****************************************************************
VERSION (B)
S C A L E S of the » P O C K E T « Model 4097_D
=================================================================
Front Side [ inverse / RED ] Back Side
=================================================================
( 0 ... 5" Ruler )
A X2
DF πX
-----------------------------------------------------------------
CF πX S sin(0.01X); sin(0.1X)
B X2
[CI] [1/X] L lgX
C X T tan(0.1X)
-----------------------------------------------------------------
D X
K X3 ( 0 ... 13 cm Ruler )
R E M A R K S : ( 1° = 60' ; 1' = 60" )
=================================================================
The TRIGONOMETRIC SCALES are divided in MINUTES & SECONDS
S keyed to B ( on BACK SIDE !); T keyed to C/D
This Celluloid Pocket-SR was found in a Flea-Market with a
broken Cursor-Window. Replacement is made of PVC from a CD-Case:
The Hairline is made with an »X-ACTO« and colored with a black
Permanent-Marker.
There is an OLDER VERSION (A) in the Collection
--------------------------------------------------
with an O L D E R L O G O and SN = 52934 ...
|
