The Future that Never Was
If Charles Babbage* had succeeded, Jules Verne might have used one of these.
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* Babbage essentially invented the computer while Queen Victoria was still a young woman. Lord Byron's daughter, by Byron's detested mathematical wife, helped him do it in one degree or another that can not now be determined. That is, Babbage would have invented the modern computer had the technology been available. He hit upon the exact idea that makes a modern computer work, but the technology available to him was brass and wood. He did the best he could, but his machine never came close to being finished. The discovering had to be done all over again in the 1930s.