The Patchwork Girl of Oz

The Patchwork Girl of Oz by L. Frank Baum is a children's novel, the 7th set in the Land of Oz. In the previous Oz book, The Emerald City of Oz, magic was used to isolate Oz from all outside worlds. Baum did this to end the Oz series, but was forced to restart the series with this book due to financial hardships. In the prologue, he explains how he managed to get another story about Oz, even though it is isolated from all other worlds. He explains that a child suggested he make contact with Oz with wireless telegraphy.