Moving into the World War II years, the circular radio directional finder antenna on top of the museum’s O-47B recalls an interesting intelligence episode early in the war: The Battle of the Beams. Knickebein (Crooked Leg) was a German program that used two radio beams to accurately navigate and bomb at night. British intelligence at the Air Ministry, led by Reginald V. Jones, were aware of the system initially because a downed German bomber’s Lorenz navigation system was analyzed and seen to be far too sensitive to be a mere landing aid. A search by the British found two German signals met over the Rolls-Royce engine plant at Derby, England. The British also secretly recorded transcripts from German POW pilots indicating the existence of bombing beams. In addition, Churchill received Ultra intelligence mentioning “bombing beams.” The German signal used a Morse code dot for the area left of the correct heading and dashes for right and they blended into the beam when on course. The British used deception by placing false dots into the German signals to confuse the bomber crews and make them miss.