2015-10-17 (Day 290) Dewdrops

I went out for a little walk to find a photo today, and came across these dewdrops gathered on a spider's web in the long grass.

It was a totally calm day, no noticeable wind whatsoever. And it was colder than it has been for previous days - so even though it was well into the afternoon the dewdrops had not evaporated away.

Look at all these little spheres of water. Aren't they beautiful? But why does the water form a sphere - shouldn't gravity be pulling the water down into the centre of the earth? Maybe the surface tension is stronger than gravity, and holds the sphere together?