Return of the Galileo thermometer. The coloured liquid inside the glass bulbs, along with the outer glass tube, makes for interesting refraction and optical effects.
I saw a spectrum refracted onto the wall which reminded me of this. I was hoping to try and photograph the thermometer with the spectrum in the background, but due to the position it was impossible. Instead, the thermometer is lying flat on some white card.
Two other shots of the Galileo Thermometer here and here. I think this most recent shot is my favourite of the three.
My dad used to have one of these, but all of his were a dark red colour - and matched his living room. It was really tall, and we sat it on the floor. Maaaan memories! This is a really nice picture by the way - I love how the sun shining through the coloured liquid creates the spectrum. Really beautiful!