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FOWLER  VEST-POCKET  CALCULATOR

       
FOWLER's Long-Scale Vest-Pocket Calculator             SN = 11726
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FOWLER & Co., Manchester / England       w.Metal-Case    ( 1900 )

Diameter = 2 11/16 " (68 mm);   Thickness = 7/16" (11 mm)

The KNOB WITH RING turns the  m o v a b l e  FRONT SCALE
The  OTHER KNOB  turns (1st)  the POINTER on FRONT SCALE
                       (2nd)  m o v a b l e  BACK SCALE
FIXED INDEXES are under the  "RING" KNOB  on BOTH SCALES

Front Scales:
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   (a) An outer "Short" (7 1/2 ") Circular Scale    1 ... 10
   (b) Six inner Circles form a "Long" (30") Scale  1 ... 10

Back Scales:
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   (a) Outer "Short" (7 1/2 ") Circular Scale  1 ... 10
   (b) 1/X                                     10 ... 1
   (c) lg(X)                                   0.01 ... 1
   (d) sqrt(X)                                 0 ... 100
   (e) sin(0.1X)                               5°45' ... 90°
   (f) tan(0.1X)                               5°45' ... 45°
   (g) sin(0.01X)                              35' ... 5°45'


S H O R T  INSTRUCTION  for  Calculations  on   F R O N T  SCALES
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LIST OF ABBREVIATIONS:       M = Middle knob turns front scales
                             R = Knop ON THE RIGHT turns
                             C = Cursor on front
                             H = Hairlines are fixed
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MULTIPLICATION  2*3*4 = 24   Set X=2 under H with M
                             Set C on X=1 with R
                             Set X=3 under C with M
                           ( Read X=6 under H )
                             Set C on X=1 with R
                             Set X=4 under C with M
                   RESULT:   Read  X=24  under H
                                   ====
DIVISION           6/3 = 2   Set X=6 under H with M
                             Set C over X=3 with R
                             Set X=1 under C with M
                   RESULT:   Read  X=2  under H
                                   ===

R E M A R K S   T O   R E S T O R A T I O N  ...
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One GLASS WAS CRACKED.  The decision was made to replace both
glasses with PVC from a CD-Case.  Hairlines are made with an
»X-ACTO« and colored with a marker in RED  ==>>  The advantage:
FIXED POINTERS are RED, the MOVABLE POINTER is (orig.) BLACK.

impressum:
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© C.HAMANN   http://public.beuth-hochschule.de/~hamann   02/24/10