An Aerial Battle. They were right in thinking warfare would also go skyward; however, a battleship based on a balloon would be a major liability these days. What French People in 1900 Thought Life Would Be Like in 2000
"Video phone technologies were available decades before finally catching on with Skype and mobile phones. Why do some technologies go nowhere, while others spread the instant they become available?" These from the middle of the Century I would think.