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WICHMANN  PRECISION   » 1417 «
( 25 cm with 50 cm Scales W1/W1' & W2/W2' )

 ``` GEBR. WICHMANN, Berlin / Germany (1930) *************************************************************** SCALES of the W I C H M A N N »PRECISION« Model 1417 =============================================================== Front Side [ inverse / RED ] Back Side =============================================================== ( 0 ... 28 cm Ruler ) L1 lg( W1 = sqrt(X) ) L2 lg( W2 = sqrt(10X) ) --------------------------------------------------------------- D X W1 sqrt(X) --------------------------------------------------------------- W1' sqrt(X) SIN 6° .. 18° ===read===>> W1' [1/W2'] [1/sqrt(10X)] SIN 19° .. 80° ===read===>> W2' [1/W1'] [1/sqrt(X)] TAN 6° .. 17° ===read===>> W1' W2' sqrt(10X) TAN 18° .. 45° ===read===>> W2' --------------------------------------------------------------- W2 sqrt(10X) SIN 2° .. 5° ===read===>> W2 --------------------------------------------------------------- K1 ( W1 = sqrt(X) )3 K2 ( W2 = sqrt(10X) )3 R E M A R K S : ( 1° = 60' ; 1' = 60" ) =============================================================== The TRIGONOMETRIC SCALES are divided in MINUTES(') & SECONDS(") Because the scales W1/W1' start at 1 and end at sqrt(10) and the scales W2/W2' start at sqrt(10) and end at 10 the 25 cm WICHMANN has the PRECISION of a 50 cm slide rule !!! This historic wooden model comes in a black cardboard case. It has a table with physical constants on its back side. In the body under the slider is a 33 ... 55 cm ruler. Historical Remarks ... Its shape with screwed scales, its table with physical data on its back side and also its cardboard case is very like the old NESTLER - AND! the pressed initials »A.N.« on the side of the »WICHMANN-1417« support it: It was made by ALFRED NESTLER. Compare the SCALE DESIGN with the NESTLER »PRAEZISION«, the POST-1442 » Dual 10"/5" POCKET-SR «, the FABER-CASTELL »COLUMBUS/A.Rohrberg« and the "modern" FABER-CASTELL »NOVO-DUPLEX« impressum: *************************************************************** © C.HAMANN http://public.beuth-hochschule.de/~hamann 03/31/08 ```