We bought this leaded and cut glass prism at a craft show in Tallahassee, Fla. probably 35 years ago not knowing it would be an accurate predictor of spring. I checked it yesterday as the sun was coming up and it was not reflecting any rainbows on the wall. Today (first day of spring) it cast two rainbows on the wall. It has been hanging in our front window since we moved here 20 + years ago. We subsequently noticed that on the first day of spring it would cast rainbows on the ceiling. This will continue through the summer and as we go deeper into spring/summer the rainbows will become more until there are so many it is magical.
The sun is just at the right place or the earth rotation is just right on the first day of spring that the small prism inside the do-dad, reflects rainbows on the walls and ceiling. We have been following it for years now and on the first day of spring it does its thing. We had no idea it would do this when we hung it up but like they say down south - even a blind hog finds an acorn sometimes.