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PICKETT   MODEL 2   ( 10" / 25 cm Scales )
Old Model :   Made of Gray Magnesium Alloy

 ``` PICKETT & ECKEL, Chicago, Illinois / USA (1945) ***************************************************************** S C A L E S of the » ALL METAL DECI LOG LOG « Model 2 ================================================================= Front Side [ white on black ] Back Side ================================================================= 3rdRoot(X< 1;4;7 Digits,.. >) 1/N1 1/10^0.001X 3rdRoot(X< 2;5;8 Digits,.. >) 1/N2 1/10^0.01X 3rdRoot(X< 3;6;9 Digits,.. >) 1/N3 1/10^0.1X L lgX 1/N4 1/10^X ----------------------------------------------------------------- T1 tan(0.1X) Explanations how to find the T2 tan(X) location of the decimal point ST arc(0.01X) S sin(0.1X); cos(0.1X) CF X/log(e) = X/M [CI] [1/X] [CI] [1/X] C X C X ----------------------------------------------------------------- D X D X; [ Co = 10s-Complement ] sqrt( X < ODD-No-Digits > ) N1 10^0.001X sqrt( X < EVEN-No-Digits > ) N2 10^0.01X N3 10^0.1X N4 10^X REMARKS: ================================================================= The CURSOR shows a Serial(?)Number = 037843 on its bottom side. The DF-Scale is folded at 1/M where e = 2.71828 = EulerConst. M = lg(e) = 0.43429 and 1/M = ln(10) = 2.30259 IT FOLLOWS: Using the D-Scale X, the N-Scales result in Power-of-10( X ) Using the DF-Scale X, the N-Scales result in Power-of-e( X ) Using the N-Scales X, the D-Scale result in lgX Using the N-Scales X, the DF-Scale result in lnX Later this idea is repeated in the famous Slide Rule N4-ES EXAMPLE of using [ Co = 10s-Complement ]-SCALE with the X-Scale: lg(0.01) = -2 = [8] - 10 ====>>> lg( 1/N ) = [Co] - 10 Historical Remarks ... This old model was made of magnesium alloy. It was oxidized and powdery on the edges and the slider was locked. For restoration it had to be disassembled, the oxidized layers scratched away and VASELINE was applied to all sliding parts. impressum: ***************************************************************** © C.HAMANN http://public.beuth-hochschule.de/~hamann 08/09/08 ```