The Queen Installs Knights of the Thistle -- The Queen, wearing the green velvet robe and black, white-plumed hat of the order of the thistle, at the installation service in St. Giles' Cathedral, Edinburgh, yesterday. The Queen, Accompanied by the Duke of Gloucester, attended service at St. Giles' Cathedral, Edinburgh, yesterday, and installed the Dukes of Buccleuch and the earl of Haddington as knights of the thistle. June 28, 1952. (Photo by Paul Popper Ltd.).