Complex sentence: Vice-Admiral Robert FitzRoy RN (5 July 1805--30 April 1865) achieved lasting fame as the captain of HMS "Beagle" during Charles Darwin's famous voyage, and as a pioneering meteorologist who made accurate weather forecasting a reality.
Split into simpler sentences: Vice-Admiral Robert FitzRoy RN (5 July 1805--30 April 1865) was a career officer of the Royal Navy and a scientist. He was a pioneering meteorologist who made accurate weather forecasting a reality.