Tell yea what timmy the tank engine if yea found my marbles yea wanna stick them in a jar with a bit of whiskey and sell them on ebay, yoe will get a nice price for um matey.
sorry breezer but that's not quite the case, they used to make lead shot in tall towers where the lead was dropped through sieves and into water over a distance to create perfectly spherical shot. some towers are still around one of them is in brentford middx
Boiling point is 99.6C but IIRC triple point is 0.01C as at that temperature both solid, liquid and gaseous states can exist - so you do get water vapour given off before the pan boils.
The stream of bubbles comes from an irregularity in the base of the pan which causes localised evaporation. . . wait for it . . . you can see a similar effect at the bottom of a full glass of beer where the bubbles will come from iregularities in the glass and not randomly (but that is CO2 coming out of solution rather than evaporation). Indeed a couple of years ago they experinented with dimpled bottoms on lager glasses as a way of generating more bubbles and making the head last longer.
Beer is more fun that water in a pan, tastes better than water when you drink it after you have seen the bubbles.