Wind socks: I remember reading in 'West with the Night' by Beryl Markham (?) how she was requested to fly out to the bush in Kenya to pick up a seriously hurt person (1930's). Middle of the night as all such requests came. Well she asked the people to mark out a runway and put up a windsock. She arrived to find the strip with little wind showing, but her landing indicated differently. Said windsock wasn't too effective. The people not knowing much had taken the description literrally, with one end open, but unfortunately the other was closed!