Notes: "The Dietzgen 1750 Maniphase slide rule falls into the category of improved Mannheim slide rules, with the standard A, B, C, and D scales of the Mannheim, plus K and CI scales. The four screws on the back are for adjusting the upper stator for alignment and slide friction. This design was patented by K&E, and that plus the “Made in USA” on the front of the slide rule, and general overall similarity to K&E slide rules, has led many to speculate that K&E made slide rules for Dietzgen. "
