What Scottish play, published in 1725, reached over 100 printings by 1800, was called ‘the noblest pastoral’ by Robert Burns, inspired more than forty paintings, more than ‘from the entire works of Chaucer, Defoe, Swift, Richardson, or Fielding’ (R. Altick, Paintings from Books), and was performed by amateur companies throughout Scotland as late as the end of the 19th century?