Because glass is a liquid and not of solid matter, it behaves like very viscous water in many situations. Ordinary sheet of glass will sink in the middle when placed on top of two supports. Similarly, in old houses one can see how the windowpanes are thin at the top and thick at the bottom. Both these phenomena are due to the fact that glass ΓÇÿflowsΓÇÖ downwards like all other liquids. This flowing depends on the raw materials and way of making the metal, and it is very slow because glass is viscous, but it is perfectly possible to observe the phenomenon.
