Shown here is one of several "Glass Engines" built by glass artist Bandhu Scott Dunham. The form of power, the various shapes, the smooth motion, the assorted colors, the levels of translucence, the inherent fragility of the material itself.
I may have used the term "astonishing" on this blog before. I don't think I had a suitable frame of reference for the word until now.
Check out the Salusa Glassworks site for more images and QuickTime movies of Bandhu's Glass Engines and a hand-cranked marble track (and WHAT A MARBLE!)