Watch 1-ton millstones grind corn at the Morris Arboretum

Find out where the phrase "grist for the mill" came from with a demo of the restored historic grist mill at UPenn's Morris Arboretum in Chestnut Hill. Giant stones will grind corn and wheat kernels, which is then sifted and made into muffins served on site.

Where: Morris Arboretum at 100 E. Northwestern Avenue

When: July 19, 2015 at 1:00 p.m. to 4:00 p.m.

How much: $5