Here are some more things to check out if you're intrigued by the public domain:
Public Domain Day — Officially, a new crop of works enters the public domain on Jan 1, the start of a new year. But the Internet Archive regularly hosts a Public Domain day, a virtual celebration of all the wonderful creativity that is now open to the the public. Keep an eye on this page on the Internet Archive’s blog for information about the next Public Domain Day!
The Public Domain Review — a wonderful journal that focuses exclusively on works in the public domain. Head here to be inspired by beautiful public domain artworks, and to read scholars' writing on works in the public domain.
Image: Detail from a page of the second volume of M. F. Lewis' Fungi Collected in Shropshire and Other Neighbourhoods,via The Public Domain Review.