A replica of a mildewed 14th- century scroll has been unfurled and displayed at a library in New York. An eagle clutching arrows and ribbons, on a tattered flag made around 1803, has just been restored and framed for viewing at a Philadelphia museum. Near Boston a museum exhibition decodes cryptic symbols like compasses and columns embossed on metal badges and embroidered onto aprons. That the public is now being enthusiastically shown these previously hidden-away items indicates that Freemasons in America are trying to shed their reclusive, somewhat fusty image. Tour guides at the groups’ lavishly ornamented lodges, mostly built...