In 1971, Boston Gas commissioned artists Corita Kent to use one of two large natural-gas tanks in Dorchester as a giant canvas.

The result was an instant landmark: a rainbow of colored stripes that greets motorists on Rte. 93 and which is the world's largest copyrighted art work.

But did Kent, active in protesting the Vietnam War, add a political statement to the piece? Look closely at the left side of the blue stripe, and you'll see a man's profile. Now follow that profile down and an unmistakable beard appears - that of Ho Chi Minh.

Kent has since died, so she's not talking. But Boston Gas ardently denies any political tinge, saying the profile is a coincidence. A couple of years ago, when the company tore down the tank with the art on it, it had it re-painted on the remaining tank. Tank purists quickly noted that the profile had a rounder, less Ho-like nose. Boston Gas insisted the rounder beak was more in keeping with what it says was Kent's original design.