A weathervane is made from a somewhat flat piece of metal that catches the air, turns on an axis, and points in the same direction as the wind. The first vane, a word that comes from the Old English for “flag,” was invented 2,000 years ago by Andronicus, a Greek astronomer who fashioned one to look like the god Triton. Since then, the simple rooftop object has taken shapes ever more elaborate. George Washington commissioned a Dove of Peace for his home in Mount Vernon. This is the first exhibition in four decades to examine the craft of weathervanes, and even its title suggests surprise—“The Art of the Winds.” —E.C.