Discharge lamps

Some years ago, I bought (from eBay) discharge lamps for helium, neon, argon, krypton and xenon, and in glass tubing bent to form the symbols for the elements. The three in this photo are the only ones still working. I suppose that the gases may have leaked out of the other two.  I've promised them to a (younger) former colleague, so took some photos as a record today.