Complex sentence: Barbier's system was found to be too difficult for soldiers to learn, and was rejected by the military; in 1821 Barbier visited the National Institute for the Blind in Paris, France, where he met Louis Braille.
Split into simpler sentences: Barbier's system was found to be too difficult for soldiers to learn and was rejected by the military. In 1821, Barbier visited the National Institute for the Blind in Paris, France, where he met Louis Braille.