Complex sentence: Although Watt is far more famous today, Newcomen rightly deserves the first credit for the widespread introduction of steam number of small steam devices of various sorts had been made, but most were essentially novelties.
Split into simpler sentences: Although Watt is far more famous today, Newcomen rightly deserves the first credit for the widespread introduction of steam power. Prior to Newcomen a number of small steam devices of various sorts had been made, but most were essentially novelties.