A.W.Faber, Geroldsgruen / Germany (1927)
************************************************************
S C A L E S of the F A B E R » RIETZ « Model 375
============================================================
Front Side Back Side
============================================================
( 0 ... 27 cm Ruler )
K X3
A X2
------------------------------------------------------------
B X2 S sin(0.1X)
ST arc(0.01X)
C X T tan(0.1X)
------------------------------------------------------------
D X
L lgX
( 0 ... 29 cm Ruler )
R E M A R K S : ( 1° = 60' ; 1' = 60" )
============================================================
The TRIGONOMETRIC SCALES are divided in MINUTES & SECONDS
This historic wooden » Model 375 « has no reciprocal scale.
On its back side is a table with technical constants.
It came in a black cardboard case.
Historical Remarks ...
Production Code = 7_3 = March 1927
impressum:
************************************************************
© C.HAMANN http://public.BHT-Berlin.de/hamann 06/12/10
|