Complex sentence: The mill was severely damaged in a storm some time during the 1870's and is rumoured to be haunted by the ghost of a heartbroken woman who threw herself from the tower around this time.
Split into simpler sentences: The mill was severely damaged in a storm some time during the 1870's. The windmill is rumoured to be haunted by the ghost of a heartbroken woman who threw herself from the tower around this time.