elimination of all interfering noises of mechanical origin at adjusting
the listening equipment only one single source remained. The nearly always
present wind caused noise due to turbulence around parts of the listening
equipment. This noise was decreased by use of a listening cabin. The cabin
was built up around the listening equipment by a reinforcement steel frame
covered with a thin more or less transparent jute cover. Without this cage
the equipment was inoperable with a wind speed of 4 m/sec. Using the
cage however listening was still possible with 6 m/sec. A second advantage
was that the listener was not disturbed by movements in his field of view.
To the disappointment of the Measurements Building, the military authorities did not support the further development, apparently in the belief that the cage was too impractical.