In late 1780 the nature of the society was to change again with the move to Birmingham of Joseph Priestley. Priestley had been closely associated with the group's activities for over a decade and was a strong advocate of the benefits of scientific societies. Shortly after his arrival Lunar meetings moved from Sunday afternoons to Mondays to accommodate Priestley's duties as a clergyman, while the society's dependence on Matthew Boulton was lessened by holding meetings at other members' houses in addition to Soho House. The result was to be the society's most productive era.