Imagine an eighteenth century farm that becomes a nineteenth century ecological disaster, a twentieth century tourist attraction, and a twenty-first century symbol of nature’s healing power. Enter through the long, low gift shop filled with every kind of tchotchke from key chains to tee shirts, pencils and shot glasses. Pony up $10.50 and you can be among tens of thousands every year that have a T.E. Lawrence moment at the Desert of Maine in Freeport, the self-proclaimed “most famous natural phenomenon” in the state. Natural? Well . . . after a fashion.