Over-arching beauty of stalactites

A READER contacted me.

There’s a stone bridge dating from the 1840s which spans a stream near his home. He was astonished when he looked under the bridge and found small stalactites hanging from the arch.

This isn’t that uncommon. If the bridge is made of limestone, or at least held together with lime mortar, and there is a constant drip of water through the masonry stalactites will form, provided there is a reasonable amount of carbon dioxide dissolved in the water.