Complex sentence: He remained quiet until March, 1878, when he rowed J. R. Hymes, of Stockton, over a two mile course on the Thames, and defeated him; and three weeks later the pair met again on the Tyne, when Hawdon was again the victor.
Split into simpler sentences: He remained quiet until March, 1878, when he rowed J. R. Hymes of Stockton, over a two mile course on the River Thames and defeated him. Three weeks later the pair met again on the River Tyne, when Hawdon was again the victor.