Chasing the prism

You asked what I was doing, so let me tell you—I went on an expedition up toward the sunshine! I climbed onto a low stool and scrambled all the way up to the wide wooden window sill. Right in the corner, there was a glass prism hanging from a cord, casting sparkling rainbow patches across the painted wood! I reached out to touch a bright violet streak, and when my finger brushed the hanging glass, it swung and sent the colors dancing all over the frame. I spent ages trying to catch each jumping patch before they flickered away!