Jean_LAMESCH_Sliderules_Collection_BOX_JL11

1776_PLATH_DREIECKRECHNER

1776_PLATH_DREIECKRECHNER

German DR2 "Dreieckrechner" (Knemeyer system) from the C. Plath company, Hamburg. Date 1942. Used by the Luftwaffe in WW2. Metal body (150mm diameter)), no case. Two moveable discs and cursor each slide. The side on the left picture is used to correct the flight direction changes caused by wind. More here and here .