A curious observation about the mid 19th century spiral map of PP that appears on the covers of several editions: Penguin Classics, Wordsworth Classics, Everyman Classics. Each of the three books show in the top right corner of the book that (with various amount of cropping) this is a "Plan of Road from The City of Destruction to the CELESTIAL CITY Engraved espressly for WILLIAMS' Elegant Edition of THE PILGRIM'S PROGRESS."
Which is all very well, except that my copy of the 1850 Edition of PP George Virtue published by George Virtue contains the same map (or at least up to the fold where it is torn off as I couldn't afford a copy with an intact map...) with an equally special dedication, this time "Engraved expressly for VIRTUE'S Elegant Edition of..."
Who got their engraved map first? Who else also had one expressly engraved for them? Is the Virtue map the same as the much publicized Williams map? And who is the promiscuous engraver expressly engraving for multiple publishers?