Details like this are why I really do love the Internet Archive's growing collection of out-of-copyright scanned in books. The detail is a small part of the cover of Jacob's The Arts in the Middle Ages.
The University of Toronto is contributing to the collection too. (Which is how I found out about the collection, thanks to gleodream.) I see old-style bar codes and know that if anyone tried to check them out, they'd need to allow an extra minute or two for the librarian to put a new-style bar code on them.
If you're looking for public domain images, advertisements, and texts, this is a treasure trove.
Note: I can't see all the pages in the PDFs with MacOS X's Preview program. Adobe Reader works just fine.