FREDERICK POST CO., Chicago, Illinois / USA (1969)
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made by HEMMI / Japan
SCALES of the POST MINI-POCKET Bamboo-Based Model 1441
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Front Side [ inverse / RED ] Back Side
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( 0 ... 4" Ruler )
A X2
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B X2 S sin(0.01X); sin(0.1X)
[CI] [1/X] L lgX
C X T tan(0.1X)
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D X
R E M A R K S : ( 1° = 60' ; 1' = 60" )
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The TRIGONOMETRIC SCALES are divided in MINUTES & SECONDS
S keyed to A/B ; T keyed to C/D
This MINI was NOT A TOY! It came in a nice leather case.
The bamboo sides are held together with a metal sheet.
HEMMI introduced a year code, starts with 1950 = "A" ...
and the month code starts with Jan. = "A" ... This slide
rule has the code "TF", means it is made in June 1969.
Historical Remarks to POST ...
Historical Remarks to HEMMI ...
impressum:
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© C.HAMANN http://public.BHT-Berlin.de/hamann 06/23/07
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