Mc Dermott’s Screw Propeller Computer
Taylor and Carpenter (Ithaca, N.Y.)
Sul lato sinistro interno sono riportate le istruzioni per l’uso. Presente la dicitura manoscritta "Regia Scuola Navale Superiore in Genova" la sigla "AS."(Angelo Scribanti). Stato di conservazione buono --- Note --- McDermott’s Screw Propeller Computer, manufactured by Taylor and Carpenter, Ithaca, NY, USA. and copyrighted in 1902 by George McDermott. Inside cover has directions for operating, and Tables for 1. Wake Percentage, 2. Surface Ratios and Propulsive Co-efficients, 3. Propulsive Co-eff Values, 4. Real Slip, 5. Relation of Characteristics. The fixed scales are for Diameter and Revolutions-Speed, and on the inner fixed scale for Indicated Horse Power. Two moving scales for Propulsive coefficient, Efficiency, Pitch Ratio,and Wake percentage. Paper scales on card folder with mock leather covering. [fonte: http://www.fleaglass.com/index.php?a=15&b=4003].