First, look at this picture:
This is frozen dew/rain, it was cold this morning and it might have rained during the night but that's not really relevant I think.
Here are my questions:
- Why is the frozen water only on the top of this rail made of stone? Why not on the sides?
- Why not on the ground?
Right now I guess that for question 1 it is gravity doing its thing, that is the water falls on the sides and thus there's very little to freeze.
For question 3 I'm guessing the stone type is different and this triggers the visible freezing, e.g the stone is not porous at all while the ground is? Or maybe the ground is warmer because it is less sensible to temperature variations (the rail being much more exposed)?