To be published, [electronic resource] : twenty mezzotinto prints, by Charles Townley, from his own drawings, After the Original Portraits of the most eminent Painters, executed by themselves, And preserved in the Great Duke's Gallery at Florence. Four of the Prints, each on half a Sheet of large Imperial Paper, will be published in May 1777, and sold for One Guinea. The rest, in Sets of the same Number and Price, as soon as possible.