Determining the speed and the direction in which the wind is blowing, is one of the most importantShih problems in meteorology. But, nevertheless, these operations are not solely, meteoorganov prerogative. "Simple," the population is engaged in parallel all the time the same, while having a purely practical interest. For this purpose known to all simple priborchik - weathervane. Its various forms, we may contact you to watch almostevery day and everywhere. In addition, almost every boy, who spent his childhood in the Soviet Union, the master. This instrument is quite simple in design, it is not surprising is it spread. If you pay attention to the design features, any vane consists of three main parts: the axis of rotation, the sail, the counterweight-pointer. OhSue rotation can be wooden or metal shaft (trumpet), which by means of a bearing support unit is mounted sail-pointer. The sail consists of a metal sheet of different shape which lends itself to the wind pressure and pivots towards its blast. On the other hand bearing assembly is opposed to a pointer, kotoing, in turn, rotates in the direction from which the wind blows. To determine the strength of the wind, you can use an ordinary propeller. Such simplicity of the design only contributes to the development of creative and practical thinking. With a little physical effort and mental work, you can create a device that will perform basicth feature and really decorate your roof.