The radiometer also as known as lightmill is an educational and physical object to demonstrate, how powerfull the sunlight is. It was developed by the English physicist Sir William Crookes (1832-1919) in the year 1873.
This physical and technical miracle shows you how sunlight is changed into kinetic energy. The sun is the energy source of the future!
The solar radiometer became a technical interesting and entertaining object for the modern living room and shows you, when it stands next to the window, every shaft of sunlight because the wings start to move.
All lightmills are NEW and got a diameter about 110mm / 80mm / 60mm with a perfectly matching drop as the border of the chain.