19. Ben's older brother John suffered from kidney stones. Ben developed a flexible urinary catheter to help him with his problem. A catheter is a thin and flexible tube inserted into a bodily passage or cavity in order to allow fluids to pass into or out of it
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27. Franklin invented a 24-hour, three-wheel clock that was much simpler than most clock designs of the time. In 1758, one of Franklin's friends, improved it.
28. Franklin developed swim fins because he was an avid swimmer. They were two wooden palettes, oval in shape and with a hole to put one's thumb.
