Complex sentence: The weld pool is central to the success of the welding process and was first observed in oxy-fuel welding by Fouché & Picard in 1903 after the discovery of acetylene by Edmund Davy in 1836.
Split into simpler sentences: The weld pool is central to the success of the welding process. It was first observed in oxy-fuel welding by Fouché & Picard in 1903, after the discovery of acetylene by Edmund Davy in 1836.