h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

On a recent visit to the Physics department I saw an experiment of Lord Kelvin's which is still going strong 30 odd years after I last saw it and about 100 years after he set it up. He set up a ladder of pitch to investigate the states of matter reckoning that pitch may not be as solid as thought.

He set up three steps really (rather than a ladder) with vertical and horizontal surfaces. A block of pitch was put in the top step and the apparatus left in a corner of the department at room temperature. It has slumped like slow moving lava through the middle step and is over halfway across the lower step. The lowest leading edge is shiny as if newly molten but the rest is dull and caked. I can't recall how much further it has gone in 30+ yr but I've no doubt someone has measured it regularly

He also set up a tall glass tube filled with water and a quantity of dye was put in the bottom. It was to measure diffusion. As I recall it some of the pink colour had got about 2/3 of the way up. It stood in the corner of the main lecture theatre but I couldn't find it last month when I was in the department. Does anyone know if it's still there?

The main lecture theatre got rebuilt and all his stuff moved. That would most likely have stuffed the diffusion experiment unless they were VERY careful when moving it. A lot of his stuff is on display in the Common Room now.