        Could these globes work on the same principle?  Each of them had two wires, supporting a thin spring.  Even the cut-away tube had a spring in it.  Might these creatures have discovered a way to use leylines to produce a glow from metal?  Or, were they able to shape darker crystals in a spiral pattern somehow?  She scribbled a note to consult with Pinkie Pie on the different methods of petriculture.