Heidelberg Army Airfield (Source: Fred Schenk, Det 3) One of the instruments inside the fenced area on the photo (below) is a so-called instrument shelter, a louvered box facing north (to not let the sun shine in when opening) which contained a "dry bulb" thermometer for measuring the air temperature and a "wet bulb" thermometer for determining the moisture in the air. The other one is part of a ceiling light, used for determinng cloud heights. The part in the enclosure was the "receiver." The "transmitter" was a light that shone straight up into the sky. It was located near the small white building in the background. In the drum-like part over my left shoulder were strong lenses and the drum traveled up and down the light beam and when the beam produced a spot on clouds, the drum reported that to a read-out instrument in the weather station. This method only worked for lower clouds and was rather crude, but in those days one could always locate an airfield at night by its light beam, if the instrument was on. The little shed (T-206) was, I seem to recall, a storage shed for weather equipment parts and tools.