Abstract
In order to make the study of the mountain air current, I have carried out an experiment using a model of mountain exposed in an air current, and a specially constructed small wind vane has been used. The vane can be shifted horizontally over the model mountain. The author has studied the stream-lines of the current. To study the motion of the vane, I have devised an optical system to take a photograph of the atitude of the vane at every position as it takes.
