Share 'What is this? eBay find.'

I found this on eBay while looking through the motion lamps. It was cheap enough, so I bought it.  It looks identical to a lava lamp base, but there's no seam or pinch. It has a color wheel and it definitely seems like something went on top (otherwise, why the pinch in the base?). It doesn't fit a 32oz. globe and it doesn't fit a 52oz. globe either. It doesn't get hot enough to heat a glitter la…