Complex sentence: In 1874 John Wainhouse sold the mill to his works manager, however, he refused to pay for the cost of building the chimney so Wainhouse decided to keep the tower for himself and use it as an observatory.
Split into simpler sentences: In 1874 John Wainhouse sold the mill to his works manager. However he refused to pay for the cost of building the chimney so Wainhouse decided to keep the tower for himself and use it as an observatory.