History of The Norden Bombsight and How It Works, Matt Clairborne aerocorner.com, "Norden was one of the first companies to combine a mechanical computer’s qualities into the actual bombsight. These computers used wheels and dials to solve complex math problems. By setting a few known factors, in this case, airspeed, altitude, and wind drift, the computer could do all of the math for the bombardier. This type of tool was called a tachometric bombsight."
