Thought you'd like that. 
I think he meant to ask about the fountain.
Muddy feet, probably. Lead is crystalline, not that you can usually see the boundaries, but think of expanded polystyrene, the size is similar. Lead is pretty unreactive. The bonds between the lead atoms in each crystal are stronger than the bonds to the atoms in the next crystal, cos they don't line up. Some ionic salts (dirty water) will react with lead , slowly. One type is what you get leeched out of cement over time. The easiest places to react with lead atoms are where the bonds to the next atoms are less strong. That's those crystal interfaces in the metal. That reduces even more the inter-crystal strength, so when you bend the pipe the crystals move apart. The surfaces are often reddish, which is why people call it rust.
I think he meant to ask about the fountain.Muddy feet, probably. Lead is crystalline, not that you can usually see the boundaries, but think of expanded polystyrene, the size is similar. Lead is pretty unreactive. The bonds between the lead atoms in each crystal are stronger than the bonds to the atoms in the next crystal, cos they don't line up. Some ionic salts (dirty water) will react with lead , slowly. One type is what you get leeched out of cement over time. The easiest places to react with lead atoms are where the bonds to the next atoms are less strong. That's those crystal interfaces in the metal. That reduces even more the inter-crystal strength, so when you bend the pipe the crystals move apart. The surfaces are often reddish, which is why people call it rust.
