He conceived an experimental set-up that would send infrared radiation through a tube of gas and into a detector, a thermopile, which would translate temperature differences into electrical current.
These bulb-shaped organs are joined to tube feet (podia) on the exterior of the animal by short linking canals that pass through ossicles in the ambulacral groove.
Each neon tube is individually blown and shaped, then filled with rarefied neon gas that is zapped with up to 15,000 volts of electricity to create that distinctive glow.