FREDERICK POST CO., Chicago, Illinois / USA (1944) **************************************************************** SCALES of the P O S T » 1442 « Dual 10"/5" POCKET-SlideRule ================================================================ Front Side [ in RED ] Back Side ================================================================ K X3 Conversion Table A X2 Fractions-to-Decimal ---------------------------------------------------------------- B X2 L lg(X1); [lg(X2)] S sin(0.1X); sin(0.01X) T tan(0.1X) [C2] [X2] C X C1 X1 *) ---------------------------------------------------------------- D X D1 X1 = sqrt(X) DI 1/X [D2] [X2] = [sqrt(10X)] D X R E M A R K S : ( 1° = 60' ; 1' = 60" ) ================================================================ The TRIGONOMETRIC SCALES are in MINUTES(') & SECONDS(") S keyed to A/B ; T keyed to C/D This SR has a mahogany body with celluloid scales and a molded acrylic cursor. The SR came in an artificial leather case. *) It is a Dual 10"/5" POCKET-SlideRule, because ... Scales C1/D1 1 .. X1 .. sqrt(10); Scales [C2/D2] sqrt(10) .. [X2] .. 100 and D = X ; X1 = sqrt(X) ; [X2] = sqrt(10X) ... Therefore this 5" POCKET has the PRECISION of a 10" SR The INSTRUCTION MANUAL ( 14 pages ) can be downloaded from ... http://www.sliderulemuseum.com/Manuals/M155 ... pdf Compare the SCALE DESIGN with the NESTLER »PRAEZISION«, the »WICHMANN-1417« ( made by A.N. = Albert Nestler), the FABER-CASTELL »COLUMBUS/A.Rohrberg« and the FABER-CASTELL »NOVO-DUPLEX« Historical Remarks ... impressum: ***************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 12/10/13 |