PICKETT & ECKEL, Alhambra, California / USA (1947) ***************************************************************** SCALES of the » ALL METAL DECI MULTIPHASE LOG LOG « Model 3 ================================================================= Front Side [ white on black ] Back Side ================================================================= 1/N1 1/10^0.001X 3rdRoot(X< 1;4;7 Digits,.. >) 1/N2 1/10^0.01X 3rdRoot(X< 2;5;8 Digits,.. >) 1/N3 1/10^0.1X 3rdRoot(X< 3;6;9 Digits,.. >) 1/N4 1/10^X DF πX DF/M X/log(e) = X/M ----------------------------------------------------------------- CF πX CF/M X/log(e) = X/M T tan(0.1X); cot(0.1X) Explanations ST arc(0.01X) how to find the location S sin(0.1X); cos(0.1X) of the decimal point [CI] [1/X] [CI] [1/X] C X C X ----------------------------------------------------------------- D X D X; [ Co = 10s-Complement ] [DI] [1/X] N1 10^0.001X sqrt( X < ODD-No-Digits > ) N2 10^0.01X sqrt( X < EVEN-No-Digits > ) N3 10^0.1X N4 10^X REMARKS: ================================================================= The CURSOR shows a Serial(?)Number = F122178 on its top side. The DF/M-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/M-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/M-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 is made of magnesium alloy. For restoration it had to be disassembled, the oxidized layers scratched away and VASELINE was applied to all sliding parts. The SR came in a worn gray soft-plastic case to hook on the user's belt - typical for the USA: As seen in the "Western Movies" ready for a "quick draw" impressum: ***************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 07/09/13 |