By the time the United States entered World War II, the military rushed to equip its bombers with the Norden bombsight. Those bombers, in most cases, had a crew of ten men: pilot, copilot, navigator, gunners, and, most crucially, bombardiers, the people who aimed and dropped the bombs. If the bombardier did not do his job, then the efforts of all nine of his crewmen were wasted.
A wartime military training film for bombardiers explained the importance of the Norden bombsight by showing aerial photographs of enemy targets:
One of them may be your target. They are the reason for your being here. The reason for all the vast equipment assembled in this and other bombardier schools. For the instructors here to train you. For the pilots here to fly you on your missions.
In all likelihood some one of you now sitting in this room will see one of these targets, not projected on a screen but moving under the crosshair of your bombsight. And where will they fall, those bombs of yours?…One hundred feet off? Five hundred feet? That will depend on how well you’ll have taught your fingers and your eyes to match the precision that has been built into your Norden bombsight.
Its official name was the Mark XV. It was dubbed “the football” by the airmen who used it. It weighed fifty-five pounds. It sat on a kind of platform—a packing box, stabilized by a gyroscope—that kept it level at all times, even as the plane was bouncing around. The bombsight was essentially an analog computer, a compact, finely machined contraption composed of mirrors, a telescope, ball bearings, levels, and dials. From a moving plane, the bombardier peered through the telescope at the target and made a fantastically complicated series of adjustments. Norden created sixty-four algorithms that he believed addressed every question of the bombing problem, including: How much do the speed and direction of the wind affect the trajectory of a bomb? How much does the air temperature affect it? Or the speed of the aircraft? To be properly trained on the Norden took six months.
Just watching the Army training film is enough to hurt your head. The narrator says,
Now look at the line in the flooring. That was your sighting line when you started. Goes straight to the target. I know: when you’re up in the air there aren’t any nice convenient lines drawn in the ground to help you. Your bombsight, though, gives you the equivalent of them. Remember how the sight’s made in two parts? Underneath, there’s the stabilizer. And in that there’s another gyro, only it has a horizontal axis.
Above that is your sight. The stabilizer is fixed in the longitudinal axis of the airplane. But you can keep turning the sight so that it’s always pointing at the target. But the sight is also connected to the stabilizer by rods. By these, the gyro controls the position of the sight, so that no matter how much the airplane yaws, the sight will always point in the same direction.
All this so the bombardier could know exactly when to shout, “Bombs away!”
McFarland explained one of the fine points of Norden’s work:
One of Norden’s sixty-four algorithms compensated for the fact that when you drop a bomb it takes thirty seconds to hit the target. During those thirty seconds, the earth actually moves as it spins on its axis.
So he actually created a formula. If it was going to take twenty seconds for the bomb to hit the target, then the earth would move—I’m going to make up a number—twelve feet. You therefore had to adjust the computer to [the fact that] the target’s now moved twelve feet. If you’re at twenty thousand feet, it might move twenty-five feet. And all of these then had to be put into this computer.
The Army bought thousands of Norden bombsights. Before every mission, the bombardier, with an armed escort, would retrieve his device from a vault. He would carry it out to the plane in a metal box. In the event of a crash landing, the bombardier was instructed to destroy the bombsight immediately, lest it fall into enemy hands. Legend has it that bombardiers were even given an eighteen-inch-long explosive device to do the trick. And, as a final precaution, they had to take a special oath: “I solemnly swear that I will keep inviolate the secrecy of any and all confidential information revealed to me, and in full knowledge that I am a guardian of one of my country’s most priceless assets, do further swear to protect the secrecy of the American bombsight, if need be, with my life itself.”
In the middle of all this drama and secrecy was Carl Norden. Maddening, eccentric Norden. Before the United States entered the war, while he was still perfecting his invention, he would sometimes leave Manhattan and return to his mother’s house, in Zurich. McFarland said this would put US officials “up in arms”：