KEUFFEL & ESSER, New York / USA SN = 540205 (1960) **************************************************************** S C A L E S of the » POLYPHASE DUPLEX « Model 681497 ================================================================ Front Side [ inverse / RED ] Back Side ================================================================ K X3 DF πX A X2 ---------------------------------------------------------------- CF πX B X2 [CIF] [1/πX] T ; [T] tan(0.1X); [tan(X)] [CI] [1/X] ST arc(0.01X) C X S sin(0.1X); [cos(0.1X)] ---------------------------------------------------------------- D X D X L lgX [DI] [1/X] R E M A R K S : ================================================================ ATTENTION: Scale [tan(X)] refers to the reciprocal [CI] scale. This model is made of mahogany with scales on celluloid veneer. The print "US" indicates a former property of the US GOVERNMENT. It came in a brown leather case. Historical Remarks ... impressum: **************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 07/13/12 |