We traveled from the top of Mendeleev's periodic table down a spiral staircase and around it. The second was written with the word "helium" in large letters. Helium, first discovered on the sun, is an inert gas. It permeates the whole earth. We used it to fill our airships, and this cabin shows us the full history of helium: from the bright green spectral lines of the corona to the black yttrium ore, a vein in Scandinavia from which the sun's gas, helium, can be pumped out.