A rather wooden television in Grizedale Forest

We loved this sculpture in Grizedale Forest, set up like an old-fashioned front room. It had been there 3 decades so the television set was a traditional vacuum tube version. In these, the screen was the wide end of a glass vacuum tube. The narrow neck of the tube was hidden in the cabinet-back of the set. In that neck was a thin wire that had a small voltage through it to get it glowing. This gave electrons enough thermal energy to be "boiled off" the wire and into the vacuum. A nearby cylindrical metal anode was set to up to +6000V and attracted the electrons. The inside of the glass tube was conducting and also at this large positive potential which allowed the electrons to pass through the anode without sticking to it. They hit the screen, which had a fluorescent coating, lighting it up. The beam was moved around the screen using vertical and horizontal electromagnets in the neck of the tube. They moved the beam so fast that the single beam seemed to be lighting up the whole screen.